Short Term Results of Cruciate Retaining TypeMobile Bearing Total Knee Arthroplasty: Using a Navigation System

PURPOSE: We wanted to report the minimum 3 year follow-up clinical results of the patients who underwent navigation guided cruciate retaining mobile bearing total knee arthroplasty and to evaluate the radiological results for a consecutive series of patients. MATERIALS AND METHODS: Cruciate retaining mobile bearing total knee arthroplasties with using a navigation system were performed for 54 knees. The mean patient age was 65 years old (range: 51~76 years). The mean follow up period was 44 months (range: 36~61 months). The Knee Society Score (KSS) and range of motion (ROM) were evaluated for the preoperative and postoperative clinical assessments. We evaluated the alignment and the position of the implants by using plane radiographs for the radiological assessment, and we investigated the wear and loosening of implants in the same manner at the last follow-up exam. RESULTS: The knee score improved from 38 to 91 (p=0.001) and the functional score improved from 46 to 92 (p=0.001). The mean range of motion was also improved postoperatively. The radiological results of the coronal axis alignment of the lower extremity and the implant position were satisfactory in 98% of the cases. Periprostheic osteolysis occurred in 4 cases, but there were no clinically significant osteolysis seen on the follow-up radiographs. CONCLUSION: Soft tissue balancing and the accuracy of implantation are necessary when performing cruciate retaining mobile bearing total knee arthroplasty. For this type of implant, navigation is useful tool to perform total knee arthorplasty for insuring the accuracy of the surgical procedure.

Hip Arthroplasty Using Cementless Modular Femoral Stem for Displaced Femoral Neck Fracture in Patients More than 70 Years Old

Purpose: To evaluate the clinical and radiological results of hip arthroplasty using a cementless modular femoral stem in patients older than 70 years with a femoral neck fracture. Materials and Methods: From January 2002 to May 2005, 67 hip arthroplasty procedures (66 patients) using a cementless modular femoral stem for displaced femoral neck fractures in patients older than 70 years of age were evaluated. All the patients were followed up for more than 2 years. The mean age at surgery was 77 (70~92) years. There were 22 men and 44 women. The mean follow up period was 31 months (24~41). The clinical evaluation was performed by examining the perioperative Activities of Daily Living (ADL) and postoperative complications. The radiological evaluation for femoral stem loosening and osteolysis was performed using the serial postoperative radiographs. The radiological evaluation for leg length discrepancies was performed using the immediate postoperative radiograph. Results: In preoperative ADL, 31 cases (46%) were in grade 1, 21 (31.5%) in grade 2, 14 (21%) in grade 3, 1 (1.5%) in grade 4 and none in grade 5. A review of the postoperative ADL revealed 25 cases (37.5%) in grade 1, 18 (27%) in grade 2, 21 (31%) in grade 3, 3(4.5%) in grade 4 and none in grade 5. Postoperative restoration of the ADL was observed in 48 cases (71.5%). There were no significant complications. Radiographically, all cases showed stable bony fixation of the femoral stem with the exception of 1 case, who showed subsidence and a pedestal reaction. Postoperative leg length discrepancy was observed in 5 cases (7.5%) but was <1 cm in all cases. Conclusion: In elderly patients older than 70 years of age with a displaced femoral neck fracture, cementless hip arthroplasty using a modular femoral stem provides good initial stability and subsequent secure bony fixation with minimal complications.

Radiological Results and Assessment of Navigation-Guided Total Knee Arthroplasty

PURPOSE: To assess the accuracy of implantation by radiologic results of navigation-guided total knee arthroplasty and compare radiologic results with navigation data. MATERIALS AND METHODS: Between September 2004 and May 2007, total knee arthroplasties were performed in 105 knees using navigation system and radiological results(group A) were compared with navigation data(group B). All patients had standing long anteroposterior radiographs of the lower extremities and supine lateral views of the knees at 6 weeks postoperatively. Mechanical axis deviation, alpha, theta, beta, gamma and delta angles were measured. Excepting alpha and gamma angles since there were no corresponding results among navigation data, reliability analysis was done for 4 angles. RESULTS: Radiological alignment on coronal plane relating to long-term prognosis were satisfactory in 97%. In analysis for reliability, mechanical axis deviation, theta, beta and delta angles showed moderate agreement. CONCLUSION: Radiological results of navigation-guided total knee arthroplasty allowed proper alignment and showed moderate agreement with navigation data, and thus navigation system will help to predict the postoperative radiological results.

Arthroscopic Treatment of Pigmented Villonodular Synovitis of the Shoulder: A Case Report

Pigmented villonodular synovitis (PVNS) is a benign proliferative lesion, involving synovial tissue in joints, tendon sheaths, and bursae. Pigmented villonodular synovitis is a rare and usually monoarticular condition and primarily affects the knee joint and hand. Polyarticular PVNS appears in less than 1% of all case and its occurrence in the shoulder is rare (<2%). We present a 64-year-old male who had pigmented villonodular synovitis of both shoulder joints, which was treated by arthroscopic total synovectomy.

Reconstruction of the Medial Collateral Ligament for the Medial Instability after Primary Total Knee Arthroplasty: A Case Report / 대한정형외과학회잡지

An absence or compromise of the medial collateral ligament that occurs after primary total knee arthroplasty is a challenging reconstructive problem. Treatment usually requires unlinked-constrained total knee arthroplasty. Revision with unlinked-constrained prostheses often causes more bone loss and transmits increased stress to the bone-cement and prosthesis-cement interfaces, which can increase the risk of aseptic loosening. However, there are no treatment options other than constrained prostheses. We present a 47-year-old female who suffered from medial instability that occurred after total knee arthroplasty, which was treated successfully by a medial collateral ligament reconstruction.