In May of 2007 at the age of 55, I underwent a hip resurfacing procedure in the right hip with fitment of a Smith and Nephew BHR metal prosthesis at Claremont Surgical in Cape Town, South Africa.  I had extensive and expensive rehabilitation and physiotherapy however I  never fully recovered and have suffered endless problems as follow:

• In 2008, my leg became swollen and the doctor fearing a thrombosis injected me with blood thinning medication.  I had a CAT scan which showed a bursar in the hip area which was collapsing the main vein – I then had a procedure to remove the liquid from the bursar but one week later the swelling returned.  I was advised to see a vascular surgeon who admitted me to hospital and inserted 2 stents, the first one collapsing under pressure from the bursar.

• In 2009 my leg again became swollen another scan showed the bursar had become tumerous and was pushing the vascular bundle against my pelvic bone and the stent had collapsed.  I was admitted to hospital where both orthopaedic and vascular surgeons operated – the stent being repaired and the tumerous mass being removed and the area around the prosthesis cleaned of debris.  The tissue was found to contain metal debris and I was found to be suffering from metallosis and an infection around the prosthesis.  I was put on a course of strong antibiotics to which I had a severe allergic reaction.  I was told no further operation on my hip was possible until this infection was cleared.  Since I can no longer afford the operation anyway I have not returned.

• From 2008, I was suffering from acute anxiety and depression which required hospitalisation and medication for several years.

• My one leg now being shorter than the other I have had stability and balance problems – unable to walk any distance because of pain and discomfort.  I believe this instability also contributed to a fall in 2010 and a second fall in 2011 – this time breaking my ankle.

• Lately I have noticed a marked deterioration in my sight as well as short term memory lapses and confusion with time lines.

I had no idea that all my problems mentioned above must clearly stem from the BHR metal prosthesis in my body, until reading an article in a magazine.

I would like to point out that besides the pain, discomfort and constant worry about what would happen next to my hip and the constant reminder because of the “clunk-clunk” when I move in certain ways, the time and the expense has taken its toll and today I have been unable to find a job and have neither pension nor savings nor medical aid as I am effectively destitute all being used to pay for the endless medical bills since my hip replacement.  I am now relying on my son for a living and am currently homeless, moving between various friends.

I approached a firm in South Africa who are involved in a class action against Du Puy.  They agreed to add me to the action as I did not realise there were a number of manufacturers of these prostheses – however on investigation they discovered I was not fitted with a Dupuy prosthesis but a Smith and Nephew “Birmingham” prosthesis. I subsequently went on line to find out what was being done to assist people who are suffering from the failure and after effects of this prosthesis in a case against this manufacturer as is being conducted against Du Puy and Johnson and Johnson.  I don’t see any cases being handled in South Africa and would like to ask your advice as to my next steps.

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ADA: Routine antibiotics not needed for patients with orthopedic implants

By DrBicuspid Staff

December 18, 2012 – There is insufficient evidence to recommend the routine use of antibiotics for patients with orthopedic implants to prevent infections prior to having dental procedures because there is no direct evidence that routine dental procedures cause prosthetic joint infections, according to new recommendations from the ADA and the American Academy of Orthopaedic Surgeons (AAOS).

The recommendations are based on a collaborative evidence-based clinical practice guideline that focuses on the possible linkage between orthopaedic implant infection and patients undergoing dental procedures.

“As clinicians, we want what is in the best interest of our patients, so this clinical practice guideline is not meant to be a stand-alone document. Instead it should be used as an educational tool to guide clinicians through treatment decisions with their patients in an effort to improve quality and effectiveness of care,” David Jevsevar, MD, MBA, chair of the AAOS Evidence Based Practice Committee, stated in a press release.

It has been long debated that patients with orthopedic implants, primarily hip and knee replacements, are prone to implant infections from routine dental procedures, he added.

“What we found in this analysis is that there is no conclusive evidence that demonstrates a need to routinely administer antibiotics to patients with an orthopedic implant, who undergo dental procedures,” Dr. Jevsevar said.

The new guidelines are based primarily on clinical research that examined a large group of patients, all having a prosthetic hip or knee and half with an infected prosthetic joint, according to Elliot Abt, DDS, MS, MSc, a general dentist in Skokie, IL, and a member of the ADA Council on Scientific Affairs who served as member of the AAOS-ADA work group.

In 2010, more than 302,000 hip replacement and 658,000 knee replacement procedures were performed in the U.S., according to the organizations. Infections can occur when foreign organisms enter the wound during or at any point following joint replacement, and can lead to additional surgery and prolonged antibiotic treatment.

“The research showed that invasive dental procedures, with or without antibiotics, did not increase the odds of developing a prosthetic joint infection,” he said.

The new guideline comprises three recommendations:

1. Recommendation one, which is based on limited evidence, supports that practitioners consider changing their longstanding practice of prescribing prophylactic antibiotics for patients who undergo dental procedures. Limited evidence shows that dental procedures are unrelated to prosthetic joint infection (PJI).
2. Recommendation two addresses the use of oral topical antimicrobials (topical antibiotic administered by a dentist) in preventing PJI in patients undergoing dental procedures. There is no direct evidence that the use of oral topical antimicrobials before dental procedures will prevent PJI.
3. Recommendation three is the only consensus recommendation in the guideline, and it supports the maintenance of good oral hygiene.

“Research is always changing and we need to work to improve clinical research databases, so in the future any type of prospective research done in this area will help shed light on prophylaxis and orthopedic infection rates,” Dr. Jevsevar said.

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Faulty hip implants have ruined lives says Orthopaedic Professor

As the Telegraph investigates the licensing process for hip implants, Professor Tom Joyce of Newcastle University explains some of the problems that can arise from poorly designed or manufactured prosthetics.

See the video in the original article here http://www.telegraph.co.uk/health/9626757/Faulty-hip-implants-have-ruined-lives-says-Orthopaedic-Professor.html

For the patients that Professor Joyce meets, the consequences of a hip replacement which fails are devastating: “Often, especially with these metal on metal hips, they have been in pain, there’s been swelling. I’ve even had some cases where adults have ended up back at home with their (elderly) parents looking after them.”

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By Ben Greenwood,

Dunkirk Lane, Hyde, Manchester, SK14 4NL.

19th October 2012

Over 300,000 hip replacements are carried out in the UK every year and the vast majority go without incident – a hip replacement is, after all, considered a ‘routine’ operation and is significantly less complicated than a lot of surgical procedures.

Metal-on-metal hip implants  - either used as ‘cap’ for the femoral bone in a hip resurfacing procedure or as a full implant in total hip replacement surgery – are one of the more prevalent hip prosthetics, accounting for around 40,000 of all hip replacements.

All hip resurfacing procedures make use of metal-on-metal hip implants; however, most total hip replacements will utilise ceramic or highly durable polythene prosthetics. Generally, you’ll be made aware of which you are receiving pre-surgery.

When successful, it’s estimated that metal-on-metal prosthetics can offer pain-free mobility for around 10 to 15 years. However, concerns have been raised over the past few years as to the safety of ‘metal-on-metal’ hip implants. Although designed with durability in mind, some metal-on-metal implants can fail and the friction between the metal can lead to metal debris breaking off and entering the bloodstream.

The cobalt and chromium particles produced by the wear and tear of a metal-on-metal joint can concentrate around the hip, causing serious damage to tissue and leading to serious pain and discomfort for a patient.

Should You Be Worried?

Perhaps the most notorious case of metal-on-metal hip implants failing is the DePuy ASL and ASL XL models, both of which have since been recalled. These implants were particularly susceptible to wear and released dangerous levels of metal into the bloodstream. It’s estimated that around 10,000 patients in the UK were fitted with these products; worldwide, this figure is much higher.

Thousands of patients have had to have follow up surgery to replace these particular implants, not to mention the pain and suffering they had to endure when the implant failed. Although recalled, there are still patients fitted with the implants. It has been recommended that these patients are monitored every year for the rest of their lives.

Beyond these particular products, however, there has been no solid evidence to suggest metal-on-metal implants are any more dangerous than other joint prosthetics. Caution should be advised, with regular monitoring carried out, but it remains that more people live comfortably after a metal-on-metal implant than suffer adverse effects.

What Should You Do If You’ve Been Affected

If you feel that are suffering from the adverse effects of a metal-on-metal hip joint, then the chances are you will require follow-up surgery to replace the prosthetic. Consult with your GP immediately; ignoring the problem will only make it worse.

In the case of DePuy implants, the company has covered the cost of consultations and follow-up surgery. However, it may be the case that you are also entitled compensation for the pain you suffered as a result of the initial implant, as well as any loss of earnings through time off work.

Once you have consulted with your doctor and had the issue resolved (your health should always come first), get in touch with a medical negligence solicitor to discuss your case. Thousands of people who have suffered as a result of orthopaedic medical negligence have successfully claimed for compensation, so don’t be afraid of pursuing your case or feel like chasing up a case is futile.

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ScienceDaily (July 26, 2012) — Thousands of veterans and warfighters returning to the U.S. suffer with limb amputations, and for many, standard prosthetics are not an option. Skin issues or short remaining-limb length can cause amputees to forgo the typical socket-type attachment systems.

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I am a GP and after months of pain and disability I had a Hip Replacement in September 2007. This was done by Mr ******* , who in view of my age (then 53yo) recommended Birmingham resurfacing with a Metal on Metal prosthesis – by Smith and Nephew. I suffered considerable post-operative pain but was out of hospital after 6 days and back at work after 6 weeks.

I regained a fairly active lifestyle, including some cricket and skiing, but have found that this year I have experienced increasing pain and stiffness in the hip, worst in the morning. I was seen in the orthopaedic clinic and have had my Cobalt and Chromium levels measured:-

May 2012

Cobalt *                     555 nmol/L N 0 – 17
Chromium *              304 nmol/L N 0 – 20

MHRA Thresholds:-
Cobalt                       7ppb equivalent to 120 nmol/L
Chromium                7ppb equivalent to 135 nmol/L

Analysed at Southampton University Hospitals NHS Trust

I assume that the symptoms I am currently experiencing are due to the Cobalt/Chromium causing local inflammation.

At any rate when Mr ***** saw the results he advised me to have the prosthesis removed and listed me for surgery on the NHS 4 weeks later.

While I appreciate that the surgery needs doing I am nevertheless apprehensive about the experience.

I spoke to the complaints department at Smith & Nephew to enquire if they would be able to defray some of the expenses of being off work. They were less than helpful, to the point of being a little rude.

I think that if they had been more polite I might have left it at that. As it is however I feel I would like to take this further.

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Hip Prostheses: New JRC report summarises current knowledge and identifies further research needs

Every year, about one million patients worldwide undergo total hip arthroplasty surgery to regain pain-free mobility. Following recent problems with certain metal-on-metal hip joint prostheses, regulators around the globe are looking into the efficiency and safety of these medical devices.

Uwe Holzwarth , Giulio Cotogno: Total Hip Arthroplasty. State of the Art, Challenges and Prospects. July 2012 (application/pdf 2035Kb) en

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Bone Cement Implantation Syndrome

PA PSRS Patient Saf Advis 2006 Dec;3(4):1,4-9.

PA-PSRS has received reports of six intraoperative cardiac arrests in patients—five resulting in death—associated with hip arthroplasties using bone cement to implant prostheses. While hip surgery is a common procedure among the elderly and generally considered safe and effective, mortality most often occurs postoperatively, usually from cardiopulmonary causes such as myocardial infarction or pulmonary emboli.1

Intraoperative deaths during hip arthroplasty occur less frequently but are almost exclusively associated with cementing of the femoral prosthesis.1,2 Although cardiac arrest and death are the most catastrophic symptoms associated with cemented arthroplasty, bone cement implantation syndrome (BCIS) is a well-recognized complex of sudden physiologic changes that occur within minutes of the use of methyl methacrylate cement to secure a prosthetic component into the femur.1-4 The cardiopulmonary complications of BCIS can be reduced through modern cementing techniques, appropriate anesthesia interventions, and adequate patient preparation, as well as avoiding the use of cement altogether.

This article presents the traditional and current opinions about the theories and causes of BCIS. In addition, this article includes information from the clinical literature on risk factors, risk reduction strategies and treatment.

BCIS: Past and Present

Intraoperative cardiorespiratory changes during total hip arthroplasties have been reported since cemented components were introduced in 1961.5,6 Theories about the cause of BCIS include the following:

• Direct effect of exothermic reaction of cement temperature7-9
• Air or gas embolism caused by polymerization of methyl methacrylate monomer7,8,10
• Hypersensitivity/anaphylactic reaction to the acrylic monomer7,9
• Reflex bradycardia7
• Increase in intramedullary pressure resulting from the introduction of hot acrylic cement (This increase could force marrow and fat into the circulation, producing pulmonary emboli.)7-9
• Fat and debris from the femoral shaft embolize from the femoral canal during cement and implant insertion3
• Toxic effects of the monomer (These effects may enhance the depressant cardiovascular effect of volatile halogenated anesthetic agents.)7
• Toxic cardiovascular effects of methyl methacrylate monomer or additives (These substances may produce hypotension when absorbed into the circulatory system.)6-9
• Increased amount of monomer absorbed by the large and well vascularized femoral shaft7,9
• Small amounts of toxic, unreacted methyl methacrylate monomer absorbed rapidly into the circulation9,11
• Embolic showers that occur during cement pressurization (Experimental studies using transesophageal echocardiography [TEE] indicate that these showers are directly correlated with changes in pulmonary parameters.)3

At one time, methyl methacrylate toxicity was considered the major cause of hemodynamic instability during arthroplasty surgery.5,11 However, this hypothesis has not been confirmed by animal studies. More than 30 times the level of methyl methacrylate ordinarily used in human arthroplasty must be used to produce significant changes in cardiopulmonary parameters.5,11,12 While absorbed monomer temporarily lowers blood pressure after insertion of bone cement, there is little evidence indicating that monomer causes severe systemic reactions.13 No correlation has been found between blood pressure changes and monomer concentration.5 Moreover, using a dog model, Orsini et al.5,11 determined that similar cardiopulmonary changes occur when using either bone cement or inert bone wax, producing high intramedullary pressures that force bone     marrow into the circulation at the time of cement and prosthesis insertion.5,11 Methyl methacrylate monomer is no longer considered the cause of cardiopulmonary dysfunction during procedures using cemented components.5

BCIS is now considered to be caused by the hemodynamic effects of medullary fat embolism, rather than the toxic effects of the cement itself.2,14 Cementing prior to prosthesis insertion causes sealing and pressurization of the femoral canal when the prosthesis is inserted. This leads to high intramedullary pressure, forcing medullary fat into the vasculature. This embolic load produces acute pulmonary hypertension that can lead to right ventricular dysfunction, ischemia, hypotension, and even sudden death.1,11,14-16 The severity of these symptoms does not correlate with the amount of methyl methacrylate used.16 Moreover, this syndrome occurs in the absence of methyl methacrylate use.16 Non-cemented arthroplasty produces lower intramedullary pressures, fewer emboli, and much less hemodynamic disturbance.2 TEE has shown that embolization of fat and marrow contents occurs with the insertion of both cemented and uncemented implants.1,12 However, the emboli associated with cement are of greater number, size, and duration.1

Trends in Prosthesis Fixation

While fixation of femoral prostheses with cement remains popular, cementless stem fixation has become more durable and clinically effective over the past two decades.17 A review of 10,299 primary total hip arthroplasties in the North American Hip and Knee Registry revealed that cement use for stem fixation declined from 66.2% of the procedures in 1995 to 38.6% in 2001 (p <0.001). Patients with good bone quality are considered good candidates for uncemented implants, particularly those with thick cortices and small medullary canals.18

Symptoms

An elderly female presented via ambulance following a fall at home. She was diagnosed as having a fracture of the left femoral neck. The patient was medically cleared for surgery based upon physical examination, normal lab work, and a normal electrocardiogram. An urgent left hemiarthroplasty was performed under spinal anesthesia. Intraoperatively, after cementing of the   prosthesis, the patient developed hypotension, bradycardia, and cardiac arrest. The surgical field was covered, and the patient was placed in supine position for cardiopulmonary resuscitation. The patient did not respond to resuscitative measures, and she expired.

The preceding account from a report submitted to PA-PSRS is an example of the onset of some BCIS symptoms in a patient. A more complete list of characteristics of BCIS includes the following:

• Systemic, life-threatening hypotension2,4,5,14,19,20
• Pulmonary hypertension2,11,14,19,20
• Increased central venous pressure20
• Pulmonary edema11
• Bronchoconstriction11
• Anoxia/hypoxemia1,5,11,14,19,20
• PETCO2 decrease4
• Cardiac dysrhythmia/arrhythmias1,4,11
• Cardiogenic shock1
• Cardiac arrest1,4,5,11,20
• Sudden death4,5,20
• Fat/marrow emboli2,11,20
• Hypothermia11
• Thrombocytopenia11

Incidence

For patients undergoing total hip arthroplasty with cemented implants, cardiopulmonary changes have contributed to intraoperative mortality ranging from 0.02% to 6.6% of the cases.5,21 Parvizi et al.1 reviewed 38,488 hip arthroplasties in 29,431 patients in an institution’s registry and found that the incidence of sudden intraoperative death during any kind of arthroplasty was 0.06%. For patients undergoing arthroplasty as a result of a fracture, however, intraoperative mortality increased to 0.18%. Those with fractures who received cemented arthroplasties had intraoperative mortality rates as high as 0.2% to 4.3%.1

Studies using TEE during hip arthroplasty indicate that intracranial and pulmonary emboli occur in from 0.5% to 2% of patients. Moreover, TEE revealed that emboli occur in most patients undergoing femoral medullary reaming and hip hemiarthroplasty.22 This suggests that embolic events during hip arthroplasty (even subclinical occurrence) are more common than generally recognized.22

Pathophysiology

Clinical and laboratory studies of cement implantation syndrome indicate the underlying cause of the systemic hypotension and sudden cardiac failure is right ventricular failure secondary to increased pulmonary artery pressure (PAP).2 Serious embolization increases the PAP and pulmonary vascular resistance (PVR), causing the thin-walled right ventricle to dilate so that the intraventricular septum shifts to the left.12 These changes decrease left ventricular compliance, reducing left ventricular filling and cardiac output.23 The resulting hypotension decreases coronary perfusion pressure. As right ventricular end-diastolic pressure increases, right coronary flow decreases, producing low systemic blood pressure and creating ischemia to the right ventricle.2,23 This process produces a vicious cycle of right ventricular depression, failure, and death.23 Such changes can occur within minutes of inserting a cemented prosthesis.2 Overall, there is a markedly decreased stroke volume of the heart accompanied by increased right ventricular area and decreased left ventricular area.12

Embolization is enhanced when tissue thromboplastin from the bone marrow, forced into the veins of the proximal femur during prosthetic insertion, activates a clotting cascade, lesions of the venous endothelium, and thrombogenesis.24

Risk Factors

Patient Factors

Elderly patients with underlying cardiovascular disease who are undergoing cemented arthroplasty for repair of a fracture are at greatest risk for developing BCIS.1 Advanced age has been associated with a higher mortality rate.1,11,25 Severe osteoporosis may place a patient at higher risk also because osteoporotic bones have enlarged porous cavities and vascular spaces, which may allow marrow contents to enter the venous system more easily.1,11 Intertrochanteric or pathologic fractures are a risk factor.1,2 This may be due to the many co-morbid conditions associated with fractures that may increase mortality risk, compared to those patients undergoing elective hip replacement. Moreover, medical optimization may not occur in many fracture cases because of the urgency of surgical repair, increasing the potential for intraoperative mortality. Those with fractures have greater blood loss preoperatively and intraoperatively, contributing to hypovolemia and hypotension.1 Pathologic fractures may be a risk factor because of pressurization of abnormal vessels in cancerous bone.2

Severe underlying cardiovascular disease makes some patients unable to tolerate the pathophysiologic effects associated with the cementing and embolic process.1,11,24 Patients are susceptible to cardiac ischemia if their preoperative cardiopulmonary reserve is limited by pre-existing pulmonary hypertension, right ventricular dysfunction, or coronary artery disease.2,23,24

The pulmonary shunt values of healthy patients or those with mild systemic disease (ASA Class 1 or 2) who sustain embolic events can be re-established uneventfully at the end of the procedure. But, in those with severe systemic disease (ASA Class 3  or 4), pulmonary shunt values are likely to remain abnormally high even postoperatively, increasing the risk of morbidity.24 The severity of the patient’s pulmonary hypertension in response to embolization is associated not only with the extent of embolization and pre-existing cardiovascular status, but also with the compliance of the pulmonary vasculature and activity of humoral reflex mechanisms.11,12

Patients with fixed heart rates cannot compensate when stroke volume decreases.12 Therefore, patients with pacemakers or those receiving a sympathetic blockade caused by epidural anesthesia are at increased risk for this syndrome.12

Patients who are hypotensive or who have inadequate volume replacement 25 pre- or intraoperatively are less able to tolerate further ischemic changes associated with this syndrome.

Femoral tumors or cancer place a patient at risk because of potential alterations in the femoral vascular architecture that may increase the risk of marrow embolization.11

Patients with large femoral canals (21 mm or more) are at risk for hypotension when cement is inserted into the femoral canal because of an increased vascular surface and a greater amount of embolizable intramedullary contents.25 Males are more likely to have larger femoral canals than women.25

Severe outcomes from emboli may be more likely in those with a patent foramen ovale (25% of the population), which allows emboli to pass to the right heart (bypassing the lungs) and into the arterial system to the brain.19

Patients who are hemodynamically unstable at the time of cementing and prosthesis insertion are more likely to develop this syndrome.2

Technique

Technical aspects of the procedure can increase embolic load.2 For example, long stem femoral components are associated with higher risk.2,11,19 Revision surgery may increase the risk of cement-related hypotension as much as four times.2,19 Yet, one study indicated that a previously undisturbed femoral canal may place the patient at higher risk.11 Patients receiving volatile general anesthesia during arthroplasty procedures may be at greater risk for BCIS than those receiving spinal anesthesia.25

The risks of intraoperative death during cemented hip arthroplasty are well known.19-21 In the study by Parvizi et al.1 mentioned previously, involving a review of over 38,000 total joint arthroplasties, 23 intraoperative deaths occurred, all during cemented hip arthroplasty procedures (p<0.001). The cardiovascular collapse of all but three of these patients occurred during the process of cementing. However, in one year, no intraoperative deaths occurred in more than 12,500 patients who had a non-cemented procedure.

The same pattern was evident in a survey of trauma centers in Wales. In one year, 15 intraoperative deaths during hemiarthroplasty occurred in 847 patients having a cemented prosthesis. In the same year, no intraoperative deaths occurred in 328 patients having non-cemented prostheses.20

The major factor in emboli development is increased intramedullary pressure from mechanical compression in the femoral canal, which in turn is produced by the bone cement and insertion of the prosthesis stem.24 The process of cementing produces a transient but significant decline in cardiac output and reduction in stroke volume.26

In a 72-patient prospective randomized clinical trial, the controls received bone cement mixed conventionally, while the experimental group received bone cement mixed in a vacuum. All patients received hemodynamic and transesophageal echocardiography during cemented hip arthroplasty procedures. The incidence of severe cardiac complications and death was significantly reduced in those receiving bone cement mixed in a vacuum.10

Risk Reduction Strategies

Surgeons and anesthesiologists can provide major patient safety interventions to reduce the risk of BCIS, including the following:

Patient Assessment

• During preoperative and preanesthetic assessments, identify risk factors, particularly the patient’s cardiopulmonary reserve, and use this information to choose the prosthesis, surgical procedure, and techniques most likely to avoid cardiopulmonary complications.1,2,23,27
• If medically feasible, defer surgery until the patient’s medical and cardiovascular status can be maximized.1

Anesthetic Techniques

• Maintaining normovolemia,23 particularly at the time of cementing and prosthesis insertion.1,2,19
• Increasing inspired oxygen concentration  by administering 100% oxygen during the procedure.19,23
• When using general anesthesia, decreasing the concentration of volatile agent prior to prosthesis insertion.2,23
• Utilizing invasive hemodynamic monitoring when pre-existing cardiopulmonary problems exist and during cementing.1,19,23
• Providing drug administration through a CVP catheter to provide access to the central circulation, improve coronary perfusion, and maintain cardiac output.2

Surgical Techniques

Patient Condition

• In the presence of pre-existing cardiopulmonary dysfunction, avoiding bilateral hip replacements with cemented prostheses23 and using non-cemented prostheses may prevent cardiovascular instability.1,19,20,23
• During the procedure, if the patient’s mean arterial pressure decreases by 20 to 30% below baseline during canal reaming or plugging, changing the technique from cemented to uncemented prosthesis to minimize embolic load.1,19

Lavage

• Conducting thorough, pulsatile, high pressure, high-volume lavage and brushing and drying of the intramedullary canal of the femoral shaft to remove tissue prior to cement insertion reduces disturbances in pulmonary function and prevents microembolization of marrow contents and the embolic response, thereby reducing the risk of fat embolism and minimizing circulatory changes.1,3,11,15,19,23,27

Venting Hole

• For long-stem prostheses, using a venting hole in the distal femur reduces distal trapping of debris and reduces pressurization by creating intramedullary drainage.1,3,5,11,15,19,21 However, drilling a venting hole may reduce the prosthesis stability or increase the risk of fracture.2

Cement Restrictor/Plug

• Using a cement restrictor may cause less physiological disturbance.17 The restrictor may help compartmentalize marrow, fat, debris, and blood, reducing the risk of BCIS,3,28 particularly if combined with other methods to reduce intramedullary pressures (e.g., a venting hole). However, for some high-risk patients, the surgeon may wish to avoid increased femoral pressurization that might occur with the sole use of a restrictor.1

Cement Preparation

• Before insertion, working the cement to  remove volatile vasodilator compounds.23
• Mixing bone cement in a vacuum.10
• Using low viscosity cement to reduce intramedullary canal pressures.21

Insertion

• Using a cement gun to apply the cement under sustained low pressure, thus avoiding excessive cement pressurization.1,11,19 The retrograde cement gun technique provides more even pressure distribution and less pressure of residual debris than finger packing of cement7 and is less likely to negatively impact physiological parameters.3,21
• Slowly introducing the prosthesis stem into the cemented femoral canal reduces pressurization, as well.19 Implant insertion     produces maximum pressure, not cement insertion.3
• Some surgeons have used vacuum along the linea aspera to drain the proximal femur to reduce high intramedullary pressure during cement and prosthesis insertion, thus reducing migration of bone marrow and fat into the venous system.24

Parvizi et al. reported that many of these risk reduction strategies reduced the overall mortality rate more than 3.5 times from the first study period (1969 to 1988) to the second study period after these changes were implemented (1988 to 1997) (p<0.05).1 This suggests that intraoperative death associated with hip arthroplasties can be reduced by interventions related to patient assessment, patient selection, intraoperative fixation techniques, and improved monitoring and anesthesia management,1 including an immediate resuscitation protocol based on the pathophysiology of right ventricular failure.2

Treatment

BCIS may be reversible with prompt basic life support, combined with treatment to maintain both coronary perfusion pressure and right heart function.14 An anesthesiologist ordinarily manages this intervention of supporting the cardiovascular system, treating right heart failure, administering 100% oxygen, and maintaining aggressive volume support. Quick initiation of hemodynamic monitoring is helpful in light of the potential for severe pulmonary hypertension and impaired cardiac output. Early placement of a pulmonary artery catheter allows use of pulmonary vasodilators, in addition to assessment   of positive end-expiratory pressure levels in extreme circumstances.11 When cement is first introduced into the femoral shaft and for about ten minutes thereafter, the anesthesiologist must be cautious about conducting anesthesia until the patient’s arterial blood pressure spontaneously returns to its initial level.9

When symptoms of BCIS occur, the anesthesiologist can administer fluid volumes to augment right ventricular preload. When CVP monitoring indicates large increases in central venous pressure, the anesthesiologist can cease fluid loading.23 Direct-acting vasopressors, such as phenylephrine or norepinephrine, can be titrated to restore adequate aortic perfusion. This process combats right ventricular ischemia and improves right ventricular function.

To improve contractility and ventricular function, anesthesia can administer inotropes, such as dobutamine, provided there is adequate right ventricular perfusion pressure to meet the increased oxygen demand caused by these agents.23 Isoproterenol can be beneficial if the patient has adequate perfusion pressure, even though it causes vasodilation. If perfusion pressure is inadequate, isoproterenol can cause further hypotension and deterioration in the patient’s condition.23

The above interventions to restore right ventricular function must be initiated immediately when symptoms of embolization occur (e.g., reduced SaO2, reduced PETCO2, tachycardia, bradycardia).23

If this syndrome does not result in sudden cardiac death, it may persist for several hours.15 BCIS is a time-limited process.2 Both human and animal studies indicate that pulmonary artery pressures normalize within 24 hours.2 Healthy hearts can recover within minutes, even from large embolic loads associated with cemented implantation. BCIS is reversible even in elderly, critically ill patients, if their hemodynamic stability is maintained by supportive therapy.2 Therefore, it is essential to immediately identify BCIS and institute aggressive measures in the operating room that address the right ventricular ischemia and failure.2,23

The ability to tolerate embolic load is related to the heart’s ability to maintain adequate right ventricular output during increased pulmonary vascular resistance.12 A key factor in maintaining cardiac output during and after embolization is the ability to increase the heart rate in the presence of decreased stroke volume.12

Notes

Parvizi J, Holliday AD, Ereth MH, et al. Sudden death during primary hip arthroplasty. Clin Orthop Relat Res 1999 Dec;(369):39-48.

Byrick RJ. Cement implantation syndrome: a time limited embolic phenomenon. Can J Anaesth 1997 Feb;44(2):107-11.

Scott S, McCaskie AW, Calder SJ, et al. Current cementing techniques in hip hemi-arthroplasty. Injury 2001 Jul;32(6):461-4.

Lafont ND, Kostucki WM, Marchand PH, et al. Embolism detected by transoesophageal echocardiography during hip arthroplasty. Can J Anaesth 1994 Sep;41(9):850-3.

Orsini EC, Byrick RJ, Mullen JBM, et al. Cardiopulmonary function and pulmonary microemboli during arthroplasty using cemented or non-cemented components. J Bone Joint Surg 1987 Jul;69-A(6):822-31.

Schuh FT, Schuh SM, Viguera MG, et al. Circulatory changes following implantation of methylmethacrylate bone cement. Anesthesiology 1973 Oct;39(4):455-7.

Nice ED. Case report: cardiac arrest following use of acrylic bone cement. Anaesth Intensive Care 1973 Feb;1(3):244-5.

Methacrylate mystery. Trans St Johns Hosp Dermatol Soc 1972;58(1):101-2.

Rezkowski J. Intraoperative complications connected with use of bone cement. Anaesth Resusc Intensive Ther 1974 Jan-Mar;  2(1):71-6.

1Werner L. A response to ‘Sudden deaths during hip hemi-arthroplasty’ Parry G. Anaesthesia 2003 Sep;58(9):922-3. In: Anaesthesia 2004 Feb;59(2):200.

Fallon KM, Fuller JG, Morley-Forster P. Fat embolization and fatal cardiac arrest during hip arthroplasty with methylmethacrylate. Can J Anesth 2001 Jul-Aug;48(7):626-9.

Murphy P, Edelist G, Byrick RJ, et al. Relationship of fat embolism to haemodynamic and echocardiographic changes during cemented arthroplasty. Can J Anaesth 1997 Dec;44(12):       1293-1300.

Kirwan WO. Systemic phenomena and bone cement. Ir J Med Sci 1973 Nov;142(6):342-5.

Jenkins K, Wake PJ. Cement implantation syndrome. Anaesthesia 2002 Apr;57(4):416.

Biomet. Bone bed preparation and pressurization in total hip replacement: fat embolism [online]. [cited 2006 Feb 3]. Available from Internet: http://www.bonecement.com/index/php?id= 16943&no_cache=1.

Parvizi J, Ereth MH, Lewallen DG. The role of methylmethacrylate monomer in the formation of haemodynamic outcome of pulmonary fat emboli. J Bone Joint Surg Br 1999 Mar;81(2):369.

Huo MH, Brown BS. What’s new in hip arthroplasty. J Bone Joint Surg Am 2003 Sep;85-A(9):1852-64.

Berry DJ, Barrack RL, McKellop HA, et al. Contemporary issues in total hip arthroplasty. Am J Orthop 2001 Aug;30(8):   626-32.

Saleh KJ, Kassim R, Yoon P. Complications of total hip arthroplasty. Am J Orthop Aug;31(8):485-8.

Parry G. Sudden deaths during hip hemi-arthroplasty. Anaesthesia 2003 Sep;58(9):922-3.

Rauh MA, Krackow KA. In-hospital deaths following elective total joint arthroplasty. Orthopedics 2004 Apr;27(4):407-11.

Narimatsu E, Kawamata M, Huse M, et al. Severe paradoxical intracranial embolism and pulmonary emboli during hip hemiarthroplasty. Br J Anaesth 2003;91(6):911-13.

Pietak S, Holmes J, Matthews R, et al. Cardiovascular collapse after femoral prosthesis surgery for acute hip fracture. Can J Anaesth 1997;44(2):198-201.

Koessler MJ, Pitto RP. Fat and bone marrow embolism in total hip arthroplasty. Acta Orthop Belg 2001;67:97-100.

Esemenli BT, Toker K, Lawrence R. Hypotension associated with methylmethacrylate in partial hip arthroplasties. Orthop Rev 1991 Jul;20(7):619-23.

Clark DI, Ahmed AB, Baxendale BR, et al. Cardiac output during hemoarthroplasty of the hip. A prospective, controlled trial of cemented and uncemented prostheses. J Bone Joint Surg Br 2001 Apr;83(3):414-8.

Breusch SJ, Heisel C. Insertion of an expandable cement restrictor reduces intramedullary fat displacement. J Arthroplasty 2004 Sep;19(6):739-44.

Biomet. Bone bed preparation and pressurization in total hip replacement: cement restrictors in the femur [online]. [cited 2006 Jan 9]. Available from Internet: http://www.bonecement.com/index.php?id=17015&no_cache=1.

Methyl Methacrylate

Methyl methacrylate (MME) is commonly found in healthcare facilities in surgical bone cement. It is a volatile, colorless liquid that has a strong, sharp, distinctive odor. It is an irritant to eyes, skin, mucous membranes, and the respiratory system. Occupational health risks from MME are mainly associated with breathing the vapors and handling the bone cement; however, it also poses explosion and fire risks (see below). MME remains in use because it forms a strong, hard polymer that bonds tightly to many other  substances. It can ensure a secure fixation of an implant to bone.

MME presents a fire hazard. When exposed to an ignition source (e.g., a Bovie), it can produce acetylene, which is an extremely flammable gas. Above the flash point (50°F), MME vapor-air mixtures can be explosive. Vapors are heavier than air and may flow to a distant ignition source and flash back.

Before working with MME, refer to the its Material Safety Data Sheet to learn of its properties, hazards, health effects, as well as requirements for storage and handling and measures for first aid, fire fighting, accidental release, exposure controls, and personal protection. Also, implement safe practices related to labeling of containers holding MME and its components, to ensure that this product is used as intended in the operative setting.

Sources

ECRI. Methyl methacrylate. Healthc Hazard Control 2004 Oct; Chemical Hazards 14.

Branson JJ, Goldstein WM. Primary total hip arthroplasty. AORN J 2003 Dec;78(6):947-74.

Mallinckrodt Baker, Inc. Material safety data sheet (MSDS). Methyl methacrylate. [online]. 2006 Feb 16 [cited 2006 Aug 31]. Available from Internet: http://www.jtbaker.com/msds/englishhtml/m5616.htm.

Pennsylvania Patient Safety Reporting System. Dangers associated with unlabeled basins, bowls, and cups. PA-PSRS Pat Saf Advis 2005 Mar;2(1):10-11.

Self-Assessment Questions

The following questions about this article may be useful for internal education and assessment. You may use the following examples or come up with your own.

1. Symptoms of bone cement implantation syndrome (BCIS) may include:
   1. Cardiac dysrhythmia/arrhythmia, hypotension, death
   2. Cardiac dysrhythmia/arrhythmia, hyperthermia, death
   3. Inflammation, pain, cellulitis
   4. Fracture, neurological impairment, osteoporosis
2. The underlying causes of BCIS symptoms include:
   1. Endocrine imbalance and erratic blood glucose control
   2. Liver and renal failure
   3. Sepsis and malignant hyperthermia
   4. Right ventricular failure and hemodynamic effects of medullary fat embolus
3. Usually BCIS symptoms occur during or within minutes of cementing the prosthesis.
   1. True
   2. False
4. BCIS risk factors include:
   1. Diseases that compromise the immune system
   2. Hypovolemia and pre-existing cardiac problems
   3. Multiple sclerosis and Parkinson’s disease
   4. Diabetes mellitus and low serum albumin
5. BCIS-specific risk reduction strategies include all but:
   1. Postponing arthroplasty until patient’s cardiac condition is stabilized
   2. Controlling intramedullary pressure
   3. Performing uncemented procedures in high-risk patients
   4. Labeling all basins, bowls, cups, and syringes used intraoperatively

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ORIGINAL ARTICLE

Year : 2012  |  Volume : 46  |  Issue : 3  |  Page : 297-303

Total hip arthroplasty for failed aseptic Austin Moore prosthesis

Pradeep Bhosale, Ashish Suryawanshi, Amber Mittal Department of Orthopaedics, Seth GS Medical College and KEM Hospital, Parel, Mumbai, India Date of Web Publication 18-May-2012

Abstract Background: Though Austin Moore (AM) replacement prosthesis has fairly good short term results for intracapsular femoral neck fractures in the elderly, it still is a compromised option and has a high failure rate in the long run. The objective of the present retrospective study is to analyze the functional outcome, assess survivorship of revision total hip arthroplasty (THA) at mid to long term followup, and evaluate intraoperative difficulties faced during conversion of failed aseptic AM prosthesis to cemented THA. Materials and Methods: Eighty-nine cemented THA surgeries for failed AM prosthesis were performed between 1986 and 2005. AM failures were classified into seven groups on the basis of mode of failure. Infected failures were excluded from the study. There were 35 men and 54 women in the study group. The mean age was 68 years (range 57-91 years). Mean followup was 8 years (range 5-13 years). Results: Average Harris Hip Score improved from 65 preoperatively (range 42-73) to 87 (range 76-90) at 1 year postoperatively and to 86 (range 75-89) at the last followup. The overall complication rate was 4.5%. Conclusion: Conversion THA is an excellent treatment strategy for symptomatic failed AM hemiarthroplasty in terms of pain relief and restoration of function and mobility as near as possible to the preinjury level. Also, hemiarthroplasty should not be used in physically active patients, even in elderly individuals. Careful patient selection for hemiarthroplasty versus THA is vital and may decrease the incidence of complications and ameliorate the outcomes in the treatment of intracapsular femoral neck fractures. Keywords: Austin Moore prosthesis, hemiarthroplasty, total hip arthroplasty    Introduction Austin Moore prosthesis, historically, has served as a good implant over the years in the management of femoral neck fracture in elderly. There are many case reports of these actually lasting a long time (>20 years). [1],[2],[3] The disadvantages of AM prosthesis are relatively poor outcomes in active patients secondary to poor femoral fixation and a marked potential for acetabular erosion. [1],[2],[3] Therefore, at this time, the indication for a Moore’s arthroplasty should be reserved for very limited or nonambulatory, low-demand patients. [1],[2],[3]However, because of less cost and good short term results, its widespread use in improperly selected patients leads to large number of failures with this type of prosthesis. [4] improper placement of the prosthesis and the resulting biomechanical disturbances within the hip joint (excessive elongation or shortening of the extremity or improper rotation of the implant) are responsible for failure of hemiarthroplasty. Inadequate calcar seating, insufficient residual femoral neck length, insufficient metaphyseal fill, and errors in sizing the prosthesis are all associated with early failure of the AM hemiarthroplasty. [5] Llinas et al. [6] reported that after femoral neck fractures, there is a tendency of the femoral neck to resorb, allowing the hemiarthroplasty to sink into the medullary canal to the level of the lesser trochanter. Conversion total hip arthroplasty (THA) for failed AM prosthesis, therefore, may be more challenging and should be done with a great deal of caution to prevent intraoperative complications. [7] The objective of the present study is to analyze the functional outcome, assess survivorship of revision THA at mid to long term followup, and evaluate intraoperative difficulties faced during conversion of failed aseptic AM prosthesis to cemented THA in a tertiary care center.    Materials and Methods Ninety-one cemented THA surgeries for failed aseptic Austin Moore (AM) prosthesis were performed at our institute between 1986 and 2005. Two patients lost to followup and were excluded from the analysis. There were 35 men and 54 women. The mean age was 68 years (range 57-91 years). All patients had displaced intracapsular femoral neck fracture as the indication for primary surgery. Mean time to failure since primary surgery was 58 months (range 1-144 months). Mean preoperative Harris Hip Score (HHS) was 65. Thirty patients were community ambulators, 34 were homebound, and 25 were bedridden. Preoperative clinical evaluation (discharging sinus, swelling, redness, warmth, etc.) laboratory investigations in form of complete blood count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were measured to exclude infection. All the patients were operated in lateral decubitus position using posterolateral approach. We found that the difficulties were mainly encountered during three major surgical steps: Exposure, dislocation of prosthesis, and extraction of prosthesis. During exposure, when external rotators and capsule were difficult to identify (because of prior surgery), the scar tissue was elevated “en masse” from the intertrochanteric ridge posteriorly to prevent sciatic nerve injury. Before dislocating, femur was lateralized with bone hook and scar tissue was released meticulously from all around the prosthesis. Then, the prosthesis was dislocated posteriorly by flexing, adducting, and internally rotating the hip, checking synchronous motion of femur with prosthesis to avoid periprosthetic fractures. The anterior capsule, any scar tissue, and osteophytes were removed at this stage. Before extraction, the piriform fossa and the proximal periprosthetic area were cleared of any bone and fibrous tissue using bone nibblers and thin osteotomes so as to visualize prosthesis extraction holes. Then, the prosthesis was extracted using devices like bone hook, universal extractor, etc. In a few cases, cortical erosion and false tract [Figure 1] were found for which we first used an interlock nailing guide wire to negotiate false tract and then femoral reaming was done over guide wire using cannulated flexible reamers. Fiberoptic headlight was used to visualize the fibrous membrane and slightly angled curettes and metal bristle roller brush were used to remove it. Femoral and acetabular preparation and cementing were done using standard techniques. The results were evaluated using Harris Hip Score recorded preoperatively, at 1 year, and at each followup visit. Mean followup duration was 8 years (range 5-13 years). For statistical analysis, paired t-test was used to evaluate possible statistical differences of preoperatively and postoperatively values. Statistical significance was set at P<0.05. Figure 1: (a) Lateral radiographs of the prosthesis showing false tract posteriorly in the shaft of femur. (b) Bypassing the false tract with cannulated reamers over guide wireClick here to view We have categorized AM prosthesis failures into seven groups on the basis of mode of failure [Table 1]. Table 1: Classification of Austin Moore prosthesis failuresClick here to view Group 1 (n=6): The patients had periprosthetic fractures [Figure 2] often involving calcar for which we used longer femoral stem bypassing the fracture site by at least two cortical diameters or 5 cm, whichever was more. It was augmented with cerclage wiring and bone graft (auto or allograft). Figure 2: (a) X-rays of right hip showing periprosthetic fracture of the femur which was (b) managed using long stem cemented total hip arthroplasty augmented with cerclage wiring and bone graftClick here to view Group 2 (n=8): The patients had implant breakage. We removed broken implants, either endofemoral (n=5) or transfemoral (n=2). In one patient, we pushed the broken implant distally so that it could act as cement restrictor. One of the revised patients had a broken stem and a dislocated Austin Moore prosthesis head [Figure 3] which was removed through endofemoral approach. In transfemoral approach, opening in the medullary canal by creating a posterolateral bony lid which remains attached to the surrounding soft tissues (extended transfemoral osteotomy) was done to extract the broken implant and long stem prosthesis was used to bypass the cortical defect. Figure 3: (a) Radiograph showing broken AM prosthesis at the junction of neck and stem with dislocation of head or prosthesis which was (b) managed successfully with cemented total hip arthroplasty as shown in the 8 year postoperative radiographClick here to view Group 3 (n=36): The patients had calcar resorption often associated with shortening. In all these patients, prostheses were loose and often associated with fibrous tissue formation which was removed using fiberoptic light. We did augmentation of calcar with bone graft [Figure 4] to restore the limb length (vertical offset). Figure 4: (a) Radiograph showing calcar resorption with shortening which was revised to cemented total hip arthroplasty (b) showing augmentation of calcar with bone graft and cementClick here to view Group 4 (n=19): The patients had protrusion acetabuli [Figure 5] which was treated with impaction bone grafting (autogenous iliac crest bone graft preferred over allograft) using impactor and reverse reaming. In severe cases, we used antiprotrusion cages (n=3). The outer wall of the ilium is exposed for several centimeters above the bone defect, and the residual bone surfaces are roughened with a burr, reamers, or an osteotome. Morsellized pieces of bone graft are then packed into bone defects, leaving room for the antiprotrusion cages. Figure 5: (a) Radiograph showing erosion of the acetabulum leading to protrusion which was (b) revised to total hip arthroplasty (3 year postoperative radiograph)Click here to view Group 5 (n=6): The patients had instability [Figure 6] as demonstrated by telescoping of prosthesis in femoral canal during traction views. These were the patients where synchronous motion of femur with prosthesis was observed while dislocating prosthesis so as to avoid periprosthetic fracture. Figure 6: (a) Radiograph suggesting instability of the prosthesis which was evident on traction view as shown in (b) by telescoping of prosthesis in femoral canalClick here to view Groups 6 (n=2) and 7 (n=12): The patients often had either proximal calcar gap or tight fit between prosthesis head and acetabulum. These were the patients where care had to be taken while dislocating prosthesis head so as to avoid acetabular and femoral fracture.    Results Average HHS improved from 65 preoperatively (range 42-73) to 87 (range 76-90) at 1 year followup and to 86 (range 75-89) till the last followup [Table 2]. Mean followup duration was 8 years (5-13 years). Harris Hip Scores were affected by the indication for conversion arthroplasty. The P values of all the groups were less than 0.001, which suggests highly significant results except in group 6 where the P value was more than 0.05 which may be because of only two patients in that group. The overall complication rate was 4.5%. Deep infection occurred in two patients, which required two stage revision surgery. Loosening occurred in two patients after 10 years followup. Revision was subsequently performed in both these patients. Our 5 patients had limb length discrepancies(<2.5 cm). The mean leg length discrepancy was 12 mm (range 5-20 mm). Six patients had persistent groin pain. Heterotopic ossification was not found in any of the patients. Dislocation occurred in one hip which was reduced by closed manipulation under anesthesia. The patient did not have any recurrence thereafter. There were no distal neurovascular deficits in our patients. Survival of revision THA prosthesis in our study at 5 years was 97.75%. Table 2: Mean Harris hip score (approximately) in relation to groups and P valueClick here to view    Discussion Elderly patients with intracapsular femoral neck fractures commonly have been treated with AM prosthesis. It has been associated with a poor quality of life in the long term, with a very high incidence of groin and thigh pain in physically active elderly patients, largely as a consequence of acetabular cartilage degeneration and stem loosening, respectively. [8],[9],[10] The percentage of unsatisfactory results quoted in literature is variable, ranging from 13%, [11] 15%, [12] 29%, [13] and 34% [14] to 48% [15] in Western series and from 9% [16] and 35% [17] to 36% [18] in Indian series. Norrish Alan [19] reported the prosthesis survivorship of 94% (90-96%) at 5 years and only 83% (65-94%) at 12 years in an 8-year followup study. Failure of AM prosthesis in our study has been attributed to non modularity of AM prosthesis stem, inadequate lateralization of stem, poor interphase between metal and cartilage, calcar loading with poor AM fixation, implant bone instability, and poor soft tissue balancing (intraoperative observation of joint laxity with shuck test). Several studies have been published concerning the results following total hip replacement in failed hemiarthroplasty. Amstutz and Smith[20] noted very high incidence of intra- as well as postoperative complications. Intraoperative femoral fractures (n=5), perforations of the medial femoral cortex (n=2), instability (n=2), infection (n=2), deep venous thrombosis (n=3), progressive loosening (n=6) out of 41 patients. Amstutz and Smith [20] and Sarmiento and Gerard [21] reported significant improvement in pain after conversion of failed endoprosthesis to THA. The d’Aubigne and Postel rating for pain improved from 3.3 to 7.9 after conversion of failed endoprosthesis in the series of Amstutz and Smith. [20] Sarmiento and Gerard [21] also reported improvement from 2.8 to 5.78 using the same scoring system. Llinas et al. [6]conducted a larger study with longer followup (mean 87 months) and they had a 6% revision rate which is comparable to the 5% revision rate for primary total hip in the same study for a similar period. Cossey and Goodwin [22] reported 46 patients who had conversion arthroplasty with 1 year followup; they had no loosening, no dislocation, two patients had superficial infection, and three patients had died at the time of the final followup. Llinas et al. [6] concluded that conversion arthroplasty had a higher rate of early loosening of the femoral component than after a primary THA, and this statement was supported by the results of Amstutz and Smith. [20] Sierra and Cabanela [7] in a larger series of 132 hemiarthroplasties that were converted to THA reported major complications in 45% including loosening in 10%, femoral fractures in 9%, and dislocations in 9.8%, after a mean followup of 7.1 years. Hammad and Abdel-Aal[23] reported no loosening in 47 patients of conversion THA after an average followup of 44 months. The reasons they stated were better cementing technique and stem design. Our study showed significant improvement in HHS following conversion arthroplasty, as found in previous studies. However, overall complication rate was significantly lower than most of the studies. Also, mean followup duration in our study, 8 years (range 5-13 years), was considerably higher than that reported in almost all studies. Deep infection occurred in two patients, which required two stage revision surgery. Loosening occurred in two patients after 10 years followup. Revision was subsequently performed in both these patients. Preoperative planning is essential in conversion THA. Assessment of acetabular and femoral bone quality, presence of endosteal cortical shell, and status of the greater trochanter are all important. Knowledge of the prior approach, range of motion, and power of the abductors are essential in planning the procedure. It may be necessary to plan ahead for a trochanteric osteotomy or trochanteric slide as proposed by Glassman et al. [24] According to our experience, the following intraoperative steps should be considered during conversion arthroplasty: En masse removal of scar tissue (capsule and external rotators’ distinction often difficult) from the intertrochanteric ridge posteriorly. Avoid inadvertent damage to the sciatic nerve during removal of scar tissue. Lateralization of femur with bone hook and release of scar tissue meticulously from all around the prosthesis prior to dislocation. Dislocate the prosthesis posteriorly by flexing, adducting, and internally rotating the hip, checking synchronous motion of femur with prosthesis to avoid periprosthetic fractures (especially in cases when there is movement between the femur and the prosthesis). In cases with a proximal calcar gap and in cases with a tight fit between prosthetic head and the acetabulum, care has to be taken to avoid fracturing the acetabulum and the femur during dislocation of the prosthetic head. Remove the anterior capsule, and any scar tissue and osteophytes to prevent retroversion of the cup. Clearance of the piriform fossa and the proximal periprosthetic area of bone and fibrous tissue in order to visualize the extraction holes of the prosthesis. In cases where bone plugs have been formed in the extraction holes, thin osteotomes should be used to remove the bone plugs. Failure to do so may lead to a periprosthetic fracture while extracting the prosthesis. Extract the prosthesis using devices like bone hook, universal extractor, etc. applying gentle force only in the direction of medullary canal. In a case of cortical erosion and a false tract, a guide wire for an interlocking nail should be used to avoid the false tract. Reaming should then be performed using cannulated flexible reamers. Use fiberoptic headlight to visualize the fibrous membrane and slightly angled curettes and a metal bristle roller brush to remove the membrane. Remnants of such a membrane may compromise the fixation of the subsequent cemented prosthesis by decreasing the total area of bone available for cement interdigitation, preventing intimate contact between cement and bone, and also by increasing the rate of endosteal bone resorption. Fragments of such fibrous membrane are metabolically very active, producing prostaglandin E2, collagenase, and interleukin 1b, all of which may contribute to resorption of adjacent bone. [25],[26],[27] In case of implant breakage, the broken stem can be extracted in two ways, either endofemoral or transfemoral. Endofemoral extraction can be accomplished anterogradely (using special extraction instruments) or retrogradely (when anterograde approach fails). A retrograde technique requires establishment of a standard retrograde femoral nailing portal and intramedullary rods to push the broken stem proximally. Sometimes, a broken implant can be pushed distally so as to act as cement restrictor. However, endofemoral approach is tedious and time consuming. Special instruments (like extraction hook, hollow mill, carbide drill, extraction cork screw) are needed when using this approach and such a technique always carries a risk of cortical perforation. The transfemoral approach includes sliding trochanteric osteotomy, extended trochanteric osteotomy, or distal fenestration of the femoral cortex to remove the broken implant. However, transfemoral approach requires bypassing the osteotomy by the new longer femoral stem with at least two canal diameters. Other methods like metal cutting ones have the risk of metallosis. Augment calcar with bone graft so as to restore the limb length (vertical offset) in cases of calcar resorption. It should be noted that the results after use of THA in displaced femoral neck fractures have been presented in several reports. Dorr et al.[28] reported no difference in results between cemented THA and cemented hemiarthroplasty, but the results associated with uncemented hemiarthroplasty were poor after a minimum duration of followup of 2 years. Function improved with time after THA but not after hemiarthroplasty. Gebhard et al. [29] demonstrated superior longevity of THA when compared with hemiarthroplasty with and without cement in 166 cases of displaced femoral neck fractures. The revision rate was 2.2% after THA, 7.9% after hemiarthroplasty with cement, and 13% after hemiarthroplasty without cement. Pain was the main reason for revision in hemiarthroplasty group. Lee et al. [30] reported their experience with primary THA in patients with femoral neck fractures. Their survivorship analysis showed a probability of survival of the prosthesis without revision of 95% at 5 years, 94% at 10 years, and 89% at 15 years. Conversion of endoprostheses to THA is challenging. Special attention should be given to the greater trochanter and to the femoral shaft to prevent intraoperative fractures. The incidence of perioperative complications in this subgroup of elderly individuals is high. When compared with primary THA after femoral neck fractures, patients having conversion from endoprostheses to THA fare worse at long term followup. [6],[7],[20] Keating et al. [31] and Blomfeldt et al. [32] reported increased pain and reduced walking ability after hemiarthroplasty compared with THA and this is in agreement with a previous review of the literature on outcomes and cost-effectiveness after surgical treatment of displaced femoral neck fractures. [33] The results from the Swedish Hip Arthroplasty Registry [34] have shown a probability for implant survival for primary THA in patients with hip fractures that is comparable with those in patients with osteoarthritis or rheumatoid arthritis. This suggests that primary THA in these elderly patients will survive their remaining lifespan, provided there are no early complications. This is in contrast to the hemiarthroplasty group, where there is a potential risk for deteriorating hip function, especially in the most active patients and in those with the longest life expectancy. [31] According to our experience, it seems reasonable to conclude that conversion arthroplasty is an excellent treatment strategy for symptomatic failed AM hemiarthroplasty in terms of pain relief and restoration of function and mobility as near as possible to the preinjury level. As to the primary treatment, there are reports in the literature showing that hemiarthroplasty should not be used in physically active patients, even in elderly individuals. [31] Careful patient selection for each type of arthroplasty (hemi versus total) after femoral neck fractures may decrease the incidence of complications and ameliorate the outcomes in the treatment of femoral neck fractures.    References 1. Klenerman L, Marcuson RW. Intracapsular fractures of the neck of the femur. J Bone Joint Surg Br 1970;52:514-7.   [PUBMED]  [FULLTEXT] 2. Clayer M, Bruckner J. The outcome of Austin-Moore hemiarthroplasty for fracture of the femoral neck. Am J Orthop 1997;26:681-4.   [PUBMED] 3. Emery RJ, Broughton NS, Desai K, Bulstrode CJ, Thomas TL. Bipolar hemiarthroplasty for subcapital fracture of the femoral neck: A prospective randomized trial of cemented Thompson and uncemented Moore stems. J Bone Joint Surg Br 1991;73:322-4.   4. Lunceford EM Jr. Use of the Moore self-locking Vitallium prosthesis in acute fractures neck. J Bone Joint Surg Am 1965;47:832-41.   [PUBMED]  [FULLTEXT] 5. Weinrauch P. Intra-operative error during Austin Moore Hemiarthroplasty. J Orthop Surg (Hong Kong) 2006;14:249-52.   [PUBMED]  [FULLTEXT] 6. Llinas A, Sarmiento A, Ebramzadeh E, Gogan WJ, Mc Kellop HA. Total hip replacement after failed hemiarthroplasty Or mould arthroplasty. Comparison of results with those of primary replacement. J Bone Joint Surg 1991;73:902-7.   7. Sierra RJ, Cabanela ME. Conversion of failed hip hemiarthroplasties after femoral neck fractures. Clin Orthop 2002;399:129-39.   [PUBMED] 8. Squires B, Bannister G. Displaced intracapsular neck of femur fracture in mobile independent patients: Total hip replacement or hemiarthroplasty. Injury 1999;30:345-8.   [PUBMED]  [FULLTEXT] 9. Gingras M, Clarke J, Evarts CM. Prosthesis replacement in femoral neck fracture. Clin Orthop Relat Res 1980;152:147-52.   10. Gowen M, Wood DD, Ihrie EJ, McGuire MK, Russell RG. An interleukin 1 like factor stimulates bone resorption in vitro. Nature 1983;306:378-80.   [PUBMED] 11. Andersson G, Nielsen JM. Results after arthroplasty of the hip with Moore’s prosthesis. Acta Orthop Scand 1972;43:397-410.   [PUBMED] 12. D’Arcy J, Devas M. Treatment of fractures of the femoral neck by replacement with a Thompson prosthesis. J Bone Joint Surg 1976;58:279-86.   13. Moore AT. The self- locking metal hip prosthesis. J Bone and Joint Surg 1957;39:811-27.   14. Salvati EA, Wilson PD. Long term results of femoral-head replacement. J Bone Joint Surg 1973;55:516-24.   15. Jensen JS, Holstein P. A long-term follow-up of Moore Arthroplasty in femoral neck fractures. Acta Orthop Scand 1975;46:764-74.   [PUBMED] 16. Saxena PS, Saraf JK. Moore prosthesis in fracture neck of femur. Indian J Orthop 1978;12:138.   17. Jadhav AP, Kulkarni SS, Vaidya SV, Divekar MM, Suralkar SP. Results of Austin Moore replacement J Postgrad Med 1996:42:33-8.   18. Kumar R, Singh T. Early results of prosthetic replacement in old neglected cases of fracture neck femur. Indian J Orthop 1980;14:1.   19. Norrish AR, Rao J, Parker MJ. Prosthesis survivorship and clinical outcome of the Austin Moore hemiarthroplasty: An 8-year mean follow-up of a consecutive series of 500 patients. Injury 2006:37:734-9.   20. Amstutz HC, Smith RK. Total hip replacement following failed femoral hemiarthroplasty. J Bone Joint Surg Am 1979;61:1161-6.   [PUBMED]  [FULLTEXT] 21. Sarmiento A, Gerard FM. Total hip arthroplasty for failed endoprosthesis. Clin Orthop 1978;137:112.   [PUBMED] 22. Cossey A, Goodwin M. Failure of Austin Moore hemiarthroplasty: Total hip replacement as a treatment strategy. Injury 2002;33:19-21.   23. Hammad A, Abdel-Aal A. Conversion total hip arthroplasty: Functional outcome in Egyptian population. Acta Orthop Belg 2006;72:549-54.   24. Glassman AH, Engh CA, Bobyn JD. Proximal femoral osteotomy as an adjunct in cementless revision total hip arthroplasty. J Arthroplasty 1987;2:47-63.   [PUBMED] 25. Goldring S, Schiller A, Roelke M, Rourke CM, O’Neil DA, Harris WH. The synovial like membrane at the bone-cement interface in loose total hip replacement and its proposed role in bone lysis. J Bone Joint Surg 1983;65:575-84.   26. Goodman S, Fornasier V, Kei J. The effects of bulk versus particulate ultra-high molecular weight polyethylene on bone. J Arthroplasty 1988;3 suppl:S41-6.   27. Gown M, Wood DD, Ihrie EJ, McGuire MK, Russell R. An interleukin 1 like factor stimulates bone resorption in vitro. Nature 1983;306:378-80.   28. Dorr LD, Glousman R, Hoy AL, Vanis R, Chandler R. Treatment of femoral neck fractures with total hip replacement versus cemented and noncemented hemiarthroplasty. J Arthroplasty 1986;1:21-8.   [PUBMED] 29. Gebhard JS, Amstutz HC, Zinar DM, Dorey FJ. A comparison of total hip arthroplasty and hemiarthroplasty for treatment of acute fracture of the femoral neck. Clin Orthop Relat Res 1992;282:123-31.   [PUBMED] 30. Lee PB, Berry Di, Harmsen WS, Sim FH. Total hip arthroplasty for the treatment of an acute fracture of the femoral neck: Long term results. J Bone Joint Surg 1998;80:70-5.   31. Keating JF, Grant A, Masson M, Scott NW, Forbes JF. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty: Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am 2006;88:249-60.   [PUBMED]  [FULLTEXT] 32. Blomfeldt R, Törnkvist H, Eriksson K, Söderqvist A, Ponzer S, Tidermark J. A randomised controlled trial comparing bipolar hemiarthroplasty with total hip replacement for displaced intracapsular fractures of the femoral neck in elderly patients. J Bone Joint Surg Br Feb 2007;89:160-5.   33. Iorio R, Healy WL, Lemos DW, Appleby D, Lucchesi CA, Saleh KJ. Displaced femoral neck fractures in the elderly: Outcomes and cost effectiveness. Clin Orthop 2001;383:229-42.   [PUBMED] 34. The Swedish National Hip Arthroplasty Registry. 2006. Available from: http://www.jru.orthop.gu.se/%5BLast cited on 2011 July 13].   Correspondence Address: Ashish Suryawanshi Department of Orthopaedics, 6th Floor, MSB, KEM Hospital, Parel, Mumbai 400 012 India

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Hinge knee prostheses yield pain relief, good stability and functional outcome.

Hinge knee prostheses yield pain relief, good stability and functional outcome

The use of hinge knee prostheses can provide pain relief, satisfactory stability and a good functional outcome for complex primary and revision total knee arthroplasty cases that cannot be remedied with condylar replacement designs, according to a study from researchers in the United Kingdom.

The findings were presented by Herbert Gbejuade at the British Orthopaedic Association and the Irish Orthopaedic Association Combined Meeting 2011, in Dublin.

“Hinges have been in use since the advent of knee replacement,” Gbejuade said. “Earlier reports of high complication rates have concerned many surgeons who use them. More recently, improvements in instrumentation and designs coupled with a rise in demand for revision surgery have led to an increase in use.”

The authors reviewed 137 consecutive hinge knee arthroplasties — 42 primary, 95 revision — accounting for eight different models, all performed between 2004 and 2010. According to the study abstract, indications for hinge use included severe instability or bone loss, recurrent dislocations, septic or aseptic loosening of the prosthesis and finally as a salvage procedure for when other prostheses had failed.

Preoperative and postoperative American Knee Society scores were used to ascertain full clinical and radiological outcomes, with follow-up occurring at 1 year, 2 years and 5 years. The team also recorded postoperative complications.

Knee ligament deficiencies that led to severe instability were the most common indication for hinge prostheses, Gbejuade said. Patients had a mean follow-up time of 4.2 years, with mean preoperative scores of 24.4 improving to 70.6 postoperatively.

Gbejuade noted postoperative complications included six cases requiring further revision due to loosening, three cases requiring manipulation under anesthesia to treat stiffness and two cases that developed infection.

“In conclusion, we present a large series of rotating hinge replacement with good medium-term outcome,” Gbejuade said, noting a low complication rate with only one patient requiring a transfemoral amputation.

Reference:

Gbejuade H, Hassaballa M, Robinson J, et al. The use of hinge prostheses in primary and revision knee surgery, the Bristol experience. Presented at the British Orthopaedic Association and the Irish Orthopaedic Association Combined Meeting 2011. Sept. 13-16. Dublin.

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