A mid-term clinical outcome study of the Advance Medial Pivot knee arthroplasty.

The Advance Medial Pivot Total Knee Arthroplasty (Wright Medical Technology, Arlington, Tennessee, USA) has been designed to reproduce modern ideas of knee kinematics. We report a prospective clinical outcome study of 284 arthroplasties in 225 consecutive patients with a mean follow-up of 6.7 years (range 4 to 9 years). For evaluation, both objective and subjective clinical rating systems and serial radiographs were used. At final follow-up, 10 (4.4%) patients (10 knees) only were lost from follow-up and four (1.8%) patients (five knees) had died for reasons unrelated to the surgery with their knees performing well. There was an 82% compliance in the intervals of follow-up evaluation. All patients showed a statistically significant improvement (p=0.01) in the Knee Society clinical rating system, WOMAC questionnaire, SF-12 questionnaire, and Oxford knee score. The majority of patients (92%) were able to perform age-appropriate activities with a mean knee flexion of 117 degrees (range 85 degrees to 135 degrees) at final follow-up. Survival analysis showed a cumulative success rate of 99.1% at 5 years. Two (0.7%) arthoplasties, in which patient selection and surgical errors were identified, were revised due to aseptic loosening, one due to infection and one due to a traumatic dislocation. This study demonstrates satisfactory mid-term clinical results for this knee design.

Autograft contamination during preparation for anterior cruciate ligament reconstruction.

BACKGROUND: The autograft preparation process for anterior cruciate ligament reconstruction has a potential for graft contamination. The purpose of this study was to evaluate the possibility of contamination of the bone-patellar tendon-bone and hamstring tendon autograft during preparation for anterior cruciate ligament reconstruction. METHODS: A primary isolated reconstruction of the anterior cruciate ligament with use of bone-patellar tendon-bone autograft (thirty patients) and hamstring tendon autograft (thirty patients) was performed in a prospective, consecutive series of patients. Three tissue samples were obtained for culture from each graft at different time-intervals during the graft preparation. In addition, the erythrocyte sedimentation rate and the C-reactive protein level were evaluated preoperatively and on the third, seventh, and twentieth postoperative days, and the clinical course of all patients was monitored. RESULTS: The time needed for graft preparation was significantly longer for hamstring autografts (nineteen minutes) than for bone-patellar tendon-bone autografts (ten minutes) (p = 0.032). In the hamstring group, cultures of graft tissue from four patients (13%) were positive for bacteria. In the bone-patellar tendon-bone group, cultures of graft tissue from three patients (10%) were positive for bacteria; the difference between groups was not significant (p = 0.923). No patient had development of a postoperative infection. There were no differences between patients with a contaminated graft and those with an uncontaminated graft with regard to postoperative changes in the erythrocyte sedimentation rate or the C-reactive protein level at all time-intervals. CONCLUSIONS: A high rate (12%) of autograft contamination can be expected during autograft preparation for anterior cruciate ligament reconstruction. The contamination rate is almost equal for both bone-patellar tendon-bone and hamstring tendon autografts. We could not identify an association between contaminated grafts implanted in the knee and postoperative inflammatory markers such as the erythrocyte sedimentation rate and the C-reactive protein level.