Amar D. Rajadhyaksha

Tennis after Total Knee Arthroplasty

In this study, patients who played tennis after undergoing a total knee arthroplasty were analyzed in terms of their functional abilities and degree of satisfaction. The patients were recruited by means of a questionnaire that was sent to players from lists supplied by the United States Tennis Association. The study group consisted of 28 men and 5 women (46 total knee replacements) with a mean age of 64 years. Only 21% (7 of 33) of the patients’ surgeons approved of their patients undertaking tennis activity, with 45% (15 of 33) recommending only doubles tennis. At both 1 year and a mean of 7 years after arthroplasty, players were playing both singles and doubles tennis approximately three times per week (range, one to seven). All tennis players polled were satisfied with their knee arthroplasties and their ability to resume playing tennis. Because the study patients played at a high level, future studies are needed to determine the effect of tennis on the general population, which does not play at such a uniformly high level. The long-term (15 to 20 years) effect of tennis activity on the clinical and radiologic outcome of total knee arthroplasty also needs to be determined.

Risk factors for pulmonary emboli after total hip or knee arthroplasty

Because it is difficult to predict which patients may sustain a pulmonary embolism after total hip or knee arthroplasty, we assessed multiple thrombophilic and hypofibrinolytic parameters to identify risk factors. Twenty-nine patients who survived a known pulmonary embolism after total knee or total hip arthroplasty were matched by age, gender, race, arthritic diagnosis, procedure, and surgery date with 29 patient-controls who had a total hip or knee arthroplasty but who did not have a symptomatic known pulmonary embolism or deep vein thrombosis. Twenty-one serologic measures and five genes associated with thrombophilia, hypofibrinolysis, or both were assessed without knowledge of group assignment. All patients with pulmonary embolism had at least one abnormality of plasminogen activator inhibitor activity, dilute Russell’s viper venom time, prothrombin time, or total cholesterol versus 13 of 27 (48%) control patients. Forty-seven percent of patients who experienced pulmonary embolism had at least two abnormalities of plasminogen activator inhibitor activity, dilute Russell’s viper venom time, prothrombin time, or total cholesterol, versus 7% of control patients. Preoperatively, to identify patients at high risk of pulmonary embolism, plasminogen activator inhibitor activity, dilute Russell’s viper venom time, prothrombin time, and cholesterol levels were most predictive. Using at least one abnormality of these four measures as a screening test to detect risk of pulmonary embolism, the test is sensitive (100%), and the predictive value of a negative test is high (100%). After additional prospective study, this may allow identification of patients at low risk (the majority of patients) in whom anticoagulation may not be required and a small group of patients at high risk for pulmonary embolism in whom prophylactic anticoagulation should be provided.

Fate of the unrevised all-polyethylene patellar component in revision total knee arthroplasty

Background: During revision total knee arthroplasty, the alternatives for addressing the well-positioned and secure all-polyethylene patellar component with minimal or no wear include retention, revision, and resection. The purpose of the present study was to determine the intermediate-term fate of all-polyethylene patellar components that were left in situ at the time of revision tibiofemoral arthroplasty.Methods: We retrospectively reviewed the results of 202 revision total knee arthroplasties, performed at four centers, in which a well-fixed, well-positioned all-polyethylene patellar component with minimal wear was retained. Clinical evaluation was performed to identify the presence of anterior knee symptoms or patellar failures, and the Knee Society clinical scores were recorded.Results: Sixty-eight percent of the revision tibiofemoral components were from a different manufacturer than the retained patellar component. Twenty-one patients (twenty-one knees; 10%) reported anterior knee pain at a mean duration of follow-up of seven years (range, two to fourteen years). Eleven of the twenty-one knees with anterior knee pain had evidence of component loosening, excessive wear, or delamination either on follow-up radiographs or on direct inspection at the time of reoperation. In the other ten knees, the findings were attributable to osseous impingement on the femoral component or soft-tissue dysfunction (including soft-tissue impingement, subluxation, and scarring). Seventeen of the twenty-one patients with anterior knee pain underwent additional surgery to address the source of the pain. Failures due to loosening or wear occurred only in patients in whom the patellar component had been sterilized with gamma irradiation in air; these failures occurred at a mean 7.3 years after revision (eleven years after primary total knee arthroplasty). The likelihood of patellar component failure was significantly greater when the component had been gamma irradiated in air than when it had been sterilized with another method (p = 0.0008). The average knee score increased from 42 to 86 points, and the average function score increased from 46 to 70 points.Conclusions: Retaining a well-positioned, stable all-polyethylene patellar component at the time of revision tibiofemoral arthroplasty can be successful, provided that the polyethylene has not oxidized. Manufacturing mismatch is acceptable with most contemporary designs provided that the patellar component articulates appropriately with the femoral implant.Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See p. 2 for complete description of levels of evidence.

Use of a Functional Temporary Prosthesis in a Two-Stage Approach to Infection at the Site of a Total Hip Arthroplasty

Two-stage revision arthroplasty is the gold standard for treatment of infection at the site of a total hip arthroplasty1-9. Unfortunately, removal of the components followed by a delay for antibiotic treatment can result in prolonged morbidity5,6. We describe two novel approaches to two-stage revision arthroplasty. ### General Description (Figs. 1-A, 2, 3) In thirty-two consecutive patients with an infection at the site of a total hip arthroplasty, we utilized a spacer composed of either the removed femoral component, which was autoclaved and then reimplanted, or an inexpensive modular femoral component. The femoral implant is coated with a mantle of antibiotic-impregnated polymethylmethacrylate before reinsertion3,7. A polyethylene acetabular liner is cemented in place with the same antibiotic-impregnated polymethylmethacrylate. The construct functions like a conventional total hip prosthesis but is intended to be utilized as a temporary implant in patients undergoing a two-stage approach to the management of an infection at the site of a total hip arthroplasty. Figs. 1-A, 1-B, and 1-C This sixty-nine-year-old patient presented with disabling pain seven years after a primary total hip arthroplasty. Fig. 1-A The preoperative anteroposterior radiograph shows loose …

Coding of diagnoses, comorbidities, and complications of total hip arthroplasty.

International Classification of Diseases coding of patient charts is used by hospitals to allow for billing of patients. Coding information also is used for assessing physician effectiveness. The purpose of the current study was to examine hospital coding for patients having total hip arthroplasty. One hundred consecutive primary total hip replacements were done at one medical center by two orthopaedic surgeons. Patient charts were coded by hospital coders according to the Health Care Finance Administration guidelines. Subsequently, an orthopaedist-based team did a secondary review of these charts and the two sets of codes were compared. The diagnostic codes were similar between the two groups for 87% (174 of 200 codes) of the cases. Comorbidities generally were undercoded by the hospital coders who reported 2.9 comorbidities per patient, whereas the secondary review reported 3.7 comorbidities per patient. The hospital coders found a complication rate of 1.2 per patient, whereas the secondary review revealed a rate of 0.4 per patient. Based on the results of the current study, the authors conclude that it is important to ensure three issues regarding the standard of coding and quality control: (1) the qualifications of the coders; (2) an interaction between coders and healthcare professionals to check that coding is accurate and reproducible; and (3) communication among various health professionals (including the primary surgeon) and coders to determine what actually are appropriate diagnoses, comorbidities, and complications.

The fate of revised uncemented acetabular components in patients with rheumatoid arthritis.

The results of patients with rheumatoid arthritis who had revision hip arthroplasty have been studied infrequently. The purpose of this study was to review the authors’ clinical and radiographic experiences and outcomes with revision hip arthroplasty. Revision total hip arthroplasties were done on 28 patients (30 hips). All hips had morselized bone grafting and four hips had bulk allografts for segmental defects. The mean age of the patients at the time of surgery was 50 years (range, 20–74 years). Patients were followed up for 4 to 15 years (mean, 7 years). At the latest followup, 14 hips (13 patients) of the 30 hips (47%) had good and excellent Harris hip score ratings. Mechanical failures included six hips (five patients) that had revision arthroplasty and two hips (two patients) that had resection arthroplasty. Six other hips (five patients) had poor Harris hip score ratings. The Kaplan-Meier survivorship curve for failure of the acetabular component revealed an 89% chance of survivorship curve for failure of the acetabular component revealed an 89% chance of survival at 60 months and a 44% chance of survival at 108 months. Based on the results of this study, revision hip arthroplasty for acetabular loosening with a cementless acetabular prosthesis has a low rate of success in patients with rheumatoid arthritis.

The Effect of Polyethylene Thickness on the Wear of Highly Cross-Linked Acetabular Liners in a “Near-Impingement” Hip Simulator Model

Introduction: Concern for stability and increased range of motion in THA has increased popularity of large femoral heads, while thin polyethylene liners have allowed acetabular component thickness to remain constant. Highly cross-linked polyethylene improves wear, but is accompanied by reduced toughness. Decreasing thickness may increase wear or cause gross fracture, especially at extremes of motion when contact between head and acetabulum nears the liner edge. We determined the effect of liner thickness on wear with large diameter heads in a near impingement model.