Midterm survival of a contemporary modular total knee replacement: a multicentre study of 1970 knees.

This retrospective study evaluated the midterm clinical and radiographic outcomes of a second-generation total knee replacement system. In a multicentre consecutive series of 1512 patients, 1970 knees were treated with the PFC Sigma knee system (Depuy, Warsaw, Indiana). The patients were reviewed for functional outcome, and underwent independent radiographic evaluation at a mean follow-up of 7.3 years (5 to 10). A total of 40 knees (2%) required revision, 17 (0.9%) for infection. The incidence of osteolysis was 2.2%. The ten-year survival with revision for any cause other than infection as the endpoint was 97.2% (95% CI 95.4 to 99.1). The PFC Sigma knee system appears to provide excellent results in the medium term.

Prevalence of dislocation after total hip arthroplasty through a posterolateral approach with partial capsulotomy and capsulorrhaphy.

The senior author altered his surgical technique during total hip arthroplasty from capsulectomy and capsulotomy with closure of the external rotator muscles to capsulotomy and capsulorrhaphy. One thousand patients (500 treated with each procedure) were studied retrospectively in order to determine the prevalences of dislocation after surgery with the two different techniques. The prevalence of dislocation was 2.8% after the capsulectomy and capsulotomy, whereas it was 0.6% after the new technique; this was a significant decrease in the rate of dislocation (p < 0.005, [symbol: see text] = 0.10).

Temporary articulating methylmethacrylate antibiotic spacer (TAMMAS). A new method of intraoperative manufacturing of a custom articulating spacer.

A temporary articulating antibiotic-impregnated cement spacer for use during the first stage of a two-stage revision of a total knee replacement that had failed because of infection was developed by one of us (W.M.G.). It is simply a knee prosthesis made of methylmethacrylate and antibiotics that is manufactured intraoperatively with use of instruments, medications, and supplies that are already available at most hospitals. This construct allows for motion of the knee during treatment of the infection, thereby reducing the risk of loss of motion after subsequent revision. The technique has been successfully utilized in five patients since 1999 and has now become our standard treatment method.

Safety of a clinical surveillance protocol with 3- and 6-week warfarin prophylaxis after total joint arthroplasty.

The charts of 1869 patients were reviewed for the occurrence of deep venous thrombosis (DVT) and pulmonary embolism after total hip or knee arthroplasty. Prophylaxis consisted of 3 (group 1; n=1235) or 6 (group 2; n=634) weeks low-dose warfarin, pneumatic compression boots worn by patients in the hospital, mobilization on the first postoperative day, and a clinical surveillance protocol. Venous ultrasound or ventilation/perfusion lung scintigraphy (V/Q) was performed only if patients became symptomatic. patients. Twenty-three (1.8%) patients were positive for DVT. Ventilation/perfusion lung scintigraphy was performed on 25 patients, and 5 (0.4%) patients were positive for pulmonary embolism. In group 2, 117 patients were evaluated for DVT, and 19 (3%) patients had positive results determined by ultrasound. Twenty-five patients were evaluated with V/Q and only 1 (0.16%) patient was positive for pulmonary embolism. No patient developed a fatal pulmonary embolism or postphlebitic syndrome. This prophylaxis protocol is an efficient and cost-effective method for the prevention of significant events after surgery.

Sequential bilateral total knee arthroplasty.

As the senior citizen population has grown, the incidence of osteoarthritis and joint replacement has increased. Bilateral total knee arthroplasty (BTKA) can be performed sequentially during one anesthetic. Studies have shown the complication rates differ only slightly for total knee arthroplasty procedures performed sequentially during one anesthetic or separately requiring two hospitalizations. With the use of staggered tourniquet deflation times, efficient OR time and motion techniques, and careful postoperative management, patients can achieve successful outcomes after BTKA during one anesthetic.

A comparison of the perioperative morbidity in total joint arthroplasty in the obese and nonobese patient.

The goal of this study was to determine if obesity is a risk factor for total joint arthroplasty. This was a retrospective review of 130 patients treated with either primary total hip arthroplasty or primary total knee arthroplasty during a two-year period (154 consecutive arthroplasties). The patients were placed in the nonobese or obese group. Obesity was defined as 20% above ideal weight for height, based on life insurance tables. There were 51 in the nonobese groups and 103 in the obese group. Charts were reviewed for a number of factors associated with postoperative complications. Operative time, intravenous fluids administered, and total blood loss were found to be slightly higher in the obese group. Only the difference in operative time proved statistically significant, however. The hospitalization time, number of days with a fever, number of transfusions, preoperative and postoperative hemoglobin levels, and days requiring intramuscular narcotics were very similar between the two groups. There were 0.29 minor complications per nonobese patient, but only 0.22 per obese patient. Major complications were encountered 0.22 times per nonobese patient and 0.10 times per obese patient. The patient is not necessarily at a higher risk for peroperative complications in total joint arthroplasty. The longevity of the implant in the obese patient was not determined in this perioperative study.

The function of the anconeus muscle.

The purpose of the present study is to determine whether the anconeus muscle contracts during abduction of the ulna. Abduction of the ulna occurs when pronation takes place around an axis passing through the head of the radius and the second digit. This is in contrast to pronation around an axis passing through the fifth digit, in which the ulna remains relatively stationary. Electromyograms of the anconeus were obtained from five subjects with the elbow supported in 90 degrees of flexion, in full extension, at rest, during supination-pronation around an axis passing through the fifth digit, and during motion around an axis through the second digit. Pronation of the forearm around the axis through the second digit resulted in the greatest amplitude of individual motor unit action potentials and the highest recruitment of additional action potentials. These findings provide evidence substantiating the function of the anconeus muscle as an abductor of the ulna.

Early mobilization of rabbit medial collateral ligament repairs: biomechanic and histologic study.

The postoperative management of repaired medial collateral ligaments is controversial. There are proponents for either early mobilization or immobilization. To contribute to an understanding of the issues, 24 adult Dutch rabbits were divided into four groups and a comparative study was made of their incised medial collateral ligaments, contrasting early immobilization with mobilization at three and six weeks. The ligaments were studied histologically and biomechanically. At three weeks, the immobilized ligaments were twice as strong as mobilized ligaments. Histologically, the immobilized ligaments demonstrated more fibroblastic reaction while the mobilized ligaments showed more mature tissue development at the repair site. There were no statistically significant differences between knees mobilized for six weeks and knees immobilized for three weeks and then subsequently mobilized for three weeks. In view of these results, the authors conclude that the deleterious effects of immobilization should be considered when planning postoperative or postinjury treatment of torn medial collateral ligaments.

Traumatic recurrent posterior dislocation of the radial head. A case report.

Traumatic recurrent isolated posterior dislocation of the radial head occurred in a 56-year-old woman. The differential diagnosis included congenital dislocation, neurovascular disorders, tumors of the forearm, and Monteggia-type fracture-dislocation. The etiology of the injury is obscure. The treatment of choice depends on the age of the patient and the status of the elbow. The characteristics distinguishing this case from others previously presented in the literature include the recurrence, posterior displacement, and age of the patient.

A comparison between arthrotomy and irrigation and multiple aspirations in the treatment of pyogenic arthritis: a histological study in a rabbit model.

Staphylococcus aureus pyogenic arthritis was produced in a group of eight rabbits. After 24 hours, all rabbits were treated with systemic procaine and benzathine penicillin for five days. Four rabbits were treated with daily aspiration, and four rabbits were treated with arthrotomy and irrigation. A study of the histology of cartilage of the lateral femoral condyle was made in the two groups. Animals treated with aspiration showed a greater degree of thinning of cartilage, acelluiarity, and cloning of chondrocytes than animals treated with arthrotomy and irrigation.