Richard H. Rothman

Why are total knee arthroplasties failing today

The incidence of failure after knee replacement is low, yet it has been reported that more than 22,000 knee replacements are revised yearly. The purpose of the current study was to determine current mechanisms of failure of total knee arthroplasties. A retrospective review was done on all patients who had revision total knee arthroplasty during a 3-year period (September 1997–October 2000) at one institution. The preoperative evaluation in conjunction with radiographs, laboratory data, and intraoperative findings were used to determine causes of failure. Two hundred twelve surgeries were done on 203 patients (nine patients had bilateral surgeries). The reasons for failure listed in order of prevalence among the patients in this study include polyethylene wear, aseptic loosening, instability, infection, arthrofibrosis, malalignment or malposition, deficient extensor mechanism, avascular necrosis in the patella, periprosthetic fracture, and isolated patellar resurfacing. The cases reviewed included patients who had revision surgery within 9 days to 28 years (average, 3.7 years) after the previous surgery. More than half of the revisions in this group of patients were done less than 2 years after the index operation. Fifty percent of early revision total knee arthroplasties in this series were related to instability, malalignment or malposition, and failure of fixation.

The use of epidural steroids in the treatment of lumbar radicular pain. A prospective, randomized, double-blind study.

Seventy-three patients with lumbar radicular pain syndromes were treated in a prospective, randomized, double-blind fashion with either seven milliliters of methylprednisolone acetate and procaine or seven milliliters of physiological saline solution and procaine. All patients had radiographic confirmation of lumbar nerve-root compression, consistent with the clinical diagnosis of either an acute herniated nucleus pulposus or spinal stenosis. No statistically significant difference was observed between the control and experimental patients with either acute disc herniation or spinal stenosis. Long-term follow-up, averaging twenty months, failed to demonstrate the efficacy of a second injection of epidural steroids administered to the patients whose pain did not respond within twenty-four hours to an injection of either eighty milligrams of methylprednisolone acetate combined with five milliliters of 1 per cent procaine or two milliliters of sterile saline combined with five milliliters of 1 per cent procaine. Therefore, a decision to use epidural steroids must be made with the realization that we failed to demonstrate its clinical efficacy in this study and that reports of serious complications of this procedure have been published.

Total joint arthroplasty: When do fatal or near-fatal complications occur?

Background: With the recent trend toward minimally invasive total joint arthroplasty and the increased emphasis on faster recovery and shorter hospital stays, it has become increasingly important to recognize the timing and severity of the various complications associated with elective total joint arthroplasty to ensure that early patient discharge is a safe practice. Methods: We evaluated the systemic and local complications associated with primary unilateral lower-extremity arthroplasties performed during one year in 1636 patients. A total of 966 patients had a primary total hip arthroplasty, and 670 had a primary total knee arthroplasty. All complications that occurred in the hospital and for six weeks following the index surgery were recorded. The circumstances leading to the complications and the details of the therapeutic intervention for each complication were recorded. Analyses were performed to predict the factors that predispose patients to serious complications. Results: One patient (0.06%) in the cohort died during the hospital stay. There were a total of 104 major (life-threatening) complications, including cardiac arrest (one), tachyarrhythmia (thirty-three), pulmonary edema or congestive heart failure (ten), myocardial infarction (six), hypotensive crisis (four), pulmonary embolus (twenty-five), acute renal failure (fourteen), stroke (six), bowel obstruction or perforation (three), and pneumothorax (one). There were seventeen major local complications. Ninety-four (90%) of the major complications occurred within four days after the index surgery. Although older age, increased body mass, and preexistent comorbidities were important predisposing factors for serious medical complications, 58% of the patients who had life-threatening complications develop had no identifiable predisposing factors. Conclusions: This study demonstrated that most of the complications of lower-extremity total joint replacement occur within the time-frame of the typical hospital stay. Given the serious nature of some of these complications and the inability to identify many of the patients who may be at risk, we caution against early discharge of patients from the hospital after elective total joint arthroplasty in the lower extremity. Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Effect of femoral component offset on polyethylene wear in total hip arthroplasty.

Seventeen staged, bilateral total hip arthroplasties performed in 17 patients were reviewed to compare side-to-side polyethylene wear. Implants used on both sides were similar except for implant offset: one hip in each patient was replaced using a femoral component having a standard implant offset, whereas the other side had a lateral offset implant. The mean followup was 5.70 years (range, 2–10.2 years) on the side with a standard femoral implant and 5.67 years (range, 2–9.7 years) on the side with a lateralized femoral component. The only statistically different parameter between the sides was the femoral component offset. All other parameters affecting polyethylene wear, such as period of followup, head size, head type, cup size, cup inclination, medialization of cup, and patientrelated factors were similar on both sides. On the side with a standard femoral component, the mean actual prosthetic offset (determined by manufacturer’s specifications) was 35.2 mm and the radiologic offset was 31.5 mm. On the side with a lateralized femoral component, the actual prosthetic offset was 42.5 mm and the radiologic offset was 40.1 mm. The difference in offsets between the sides was statistically significant. The mean preoperative offset of the femur was 38.8 mm. Regression analysis revealed that only femoral component offset and cup size correlated significantly with linear wear rate. On the side with a standard femoral component, the linear wear rate was 0.21 mm per year, whereas on the side with a lateralized femoral component, the linear wear rate was 0.10 mm per year. The differences in the linear wear rates were significant. Lateralization of the femoral component in this series more closely restored preoperative hip biomechanics and significantly decreased polyethylene wear.

Evaluation of the painful prosthetic joint: Relative value of bone scan, sedimentation rate, and joint aspiration

Seventy-two joint arthroplasties undergoing total hip or total knee surgery were studied prospectively with plain radiographs, three-phase bone imaging (3PBI), erythrocyte sedimentation rate (ESR), aspiration of the joint for culture, and multiple intraoperative cultures at the time of revision. Intraoperative cultures and the operative appearance were used to form a diagnosis of definite infection (unequivocal microbiology and gross sepsis), possible infection (positive microbiology or gross sepsis), or no infection (neither positive microbiology nor gross sepsis). For the preoperative diagnosis of infection, as opposed to aseptic loosening, 3PBI alone had a sensitivity of 33% and a specificity of 86%. In conjunction with plain radiographs, minimal improvement in accuracy was seen. A preoperative ESR greater than 30 had low sensitivity (60%) and a specificity of (65%). However, the ESR was statistically significantly higher in the joints with definite infection as compared to those joints without infection. The preoperative joint aspiration had a sensitivity of 67% and a specificity of 96% and, therefore, appears to be the most useful single test in the workup of a painful total joint arthroplasty.

The Noisy Ceramic Hip: Is Component Malpositioning the Cause?

Noisy ceramics bearing surfaces are a recently recognized problem in total hip arthroplasty. Component malposition as a potential cause has been proposed. Squeaking occurred in 28 (2.7%) of 999 patients undergoing ceramic on ceramic total hip arthroplasty at our institution. Patients were matched, in a 1:2 ratio by anthropometric and demographic variables and also prosthesis size and type. The acetabular position was measured using radiographs and computed tomography. There was no statistically significant difference in cup inclination (P = .25) or version (P = .38) between groups. Four hips that have been revised were available for retrieval analysis. Stripe wear and metal transfer to ceramic components were observed. Etiology of squeaking ceramic total hip arthroplasty remains elusive. Although malposition could be an important contributing factor, the latter cannot be the sole reason based on our findings. Further investigation to elucidate the etiology is warranted.

Long-term results of lumbar spine surgery complicated by unintended incidental durotomy

Unintended incidental durotomy is not an infrequent complication of spinal surgery (incidence, 0.3-13% reported). Although prompt repair is advocated, little has been written regarding any consequences of primarily repaired durotomles on long-term patient outcome. A retrospective review of 450 patients undergoing lumbar spine surgery revealed 17 cases (4%) of incidental durotomy, recognized intraoperatively and repaired primarily. These patients were evaluated at long-term follow-up (mean, 25.1 months); and their results were compared with controls matched for age, diagnosis, procedure, and length of follow-up. No differences of statistical significance could be identified in comparing the outcomes of the two groups. Incidental durotomy, when recognized and repaired intraoperatively, does not increase perioperative morbidity or compromise final result.

In Hospital Complications After Total Joint Arthroplasty

Total joint arthroplasty is a safe and successful procedure. However, numerous complications may present after elective arthroplasty. This study prospectively collected data on systemic and local in hospital complications after 15383 joint arthroplasties, which included 8230 total hip arthroplasties and 7153 total knee arthroplasties. In general, the incidence of complications was higher after knee arthroplasty, simultaneous bilateral surgery, and revision surgery. There were 22 (0.16%) deaths in this cohort. We identified 486 major systemic complications, the most common was pulmonary embolism (152), followed by tachyarrhythmia (92) and acute myocardial infarction (36). There were 109 major local complications, including 16 vascular injuries, 29 peripheral nerve injuries, 25 periprosthetic fractures, and 18 dislocations. Total joint arthroplasty, despite its success, can be associated with rare serious and life-threatening complications. This study provides a baseline of complications that can occur after elective joint arthroplasty.

Simultaneous bilateral versus unilateral total knee arthroplasty. Outcomes analysis.

One hundred consecutive, primary simultaneous bilateral total knee arthroplasties were prospectively compared with 100 consecutive, primary unilateral total knee arthroplasties in reference to relative risk, complications, cost, and need for rehabilitation. All procedures were performed using identical preoperative, intraoperative, and postoperative protocols. Postoperative confusion was approximately four times greater in the simultaneous bilateral total knee arthroplasties group (29% versus 7%), which was thought to represent an increased incidence of fat embolism. Cardiopulmonary complications were approximately three times greater after simultaneous bilateral total knee arthroplasties (14% versus 5%), and most commonly involved arrhythmias. The increased stress on the cardiopulmonary system with simultaneous bilateral total knee arthroplasties may make this procedure contraindicated in certain patients with preexisting disease. There was an approximately 17 times greater need for banked blood in the simultaneous bilateral total knee arthroplasties group (17% versus 1%), which is alarming given the persistent concerns of transfusion related disease transmission. Although the length of hospitalization was similar (6.4 days simultaneous bilateral total knee arthroplasties versus 6 days unilateral total knee arthroplasty), 89% of the patients in the simultaneous bilateral total knee arthroplasties group required a rehabilitation stay versus 45% of the patients in the unilateral total knee arthroplasty group. Total hospital charges averaged

Predicting Quality-of-life Outcomes Following Total Joint Arthroplasty Limitations of the SF-36 Health Status Questionnaire

53,168 for simultaneous bilateral total knee arthroplasties versus