Subsidence of Polyetheretherketone Cage after Anterior Cervical Fusion / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to evaluate the rate and direction of subsidence that occurred after anterior cervical discectomy and fusion using the polyetheretherketone (PEEK) cage and to analyze the risk factors of subsidence. MATERIALS AND METHODS: Thirty two patients (36 segments) who underwent anterior cervical discectomy and fusion using the PEEK cage and autologous cancellous iliac bone graft from July 2003 to November 2011 were enrolled in this study. anterior segmental height (ASH), posterior segmental height (PSH) and cage corner distance (CCD) were measured on plain radiographs. Subsidence was defined as > or =2 mm decrease in the average of ASH and PSH at the final follow up compared to that measured in the immediate postoperative period. A decrease of more than 3 mm was defined as severe subsidence for further statistical analysis. RESULTS: Subsidence of more than 2 mm was observed in 14 segments (38.9%) and severe subsidence (> or =3 mm) was observed in seven segments (19.4%). The direction of subsidence was examined by comparison of means of decreased ASH and PSH and anterior subsidence outweighed posterior subsidence (p<0.001). Examination of CCD showed that inferior subsidence was more frequent than superior subsidence (p<0.001, p=0.047). Among the suspicious risk factors for subsidence, intraoperative disc space distraction (anterior distraction: p=0.031, posterior distraction: p=0.007) and height of inserted cage (p=0.032) showed statistical significance. CONCLUSION: Considerable incidence of subsidence was observed after use of the cage. Using a cage of appropriate height and prevention of intraoperative over-distraction of disc space will be helpful to prevention of subsidence of the cage after anterior cervical discectomy and fusion using the PEEK cage.

Double Parallel Plates Fixation for Distal Humerus Fractures

PURPOSE: The purpose of this study was to review the outcome of fixation of distal humerus fractures using recently-introduced double parallel plate system in sagittal plane. MATERIALS AND METHODS: From May 2004 to June 2008, seventeen patients with distal humerus fractures underwent primary open reduction and internal fixation with double parallel plates. According to the AO classification, there were 2 A3, 2 C1, 7 C2, and 6 C3 type fractures. Outcome assessment was performed by using the Mayo Elbow Performance index (MEPI). RESULTS: At a mean follow up of 18 (range, 12 to 32) months, 4 patients were rated as excellent, 8 as good, and 5 as fair in terms of MEPI. The average arc of elbow flexion after primary operation was 116 (range, 90~140) degrees with a mean flexion contracture of 13 (range, 0 to 30) degrees. One patient required reoperation due to fixation failure and six patients underwent capsulolysis and three patients underwent ulnar nerve neurolysis. The time to begin elbow motion exercise had negative correlation with total elbow range of motion and multiple trauma patients had significantly lower MEPI functional score compared to those without combined injury. CONCLUSION: Double parallel plating allowed adequate fixation for distal humerus fractures regardless of patient age and fracture pattern. Partial ankylosis and unlar nerve compression symptoms were the main causes of reoperation.

Retrograde Intramedullary Nailing for Periprosthetic Supracondylar Fractures of the Femur after Total Knee Arthroplasty

BACKGROUND: Periprosthetic supracondylar fractures of the femur after total knee arthroplasty are not common but are usually difficult to treat due to the advanced age of patients and frequently accompanying osteoporosis. Retrograde intramedullary nailing can be effective in promoting healing of these fractures by providing sufficient stability, but the number of beneficiaries is small due to its limited applicability and the postoperative function has rarely been assessed. This study evaluated the efficacy of retrograde intramedullary nailing for the treatment of periprosthetic supracondylar fractures of the femur using the clinical outcomes. METHODS: Between January 2000 and May 2006, 9 patients (10 knees) with periprosthetic supracondylar fractures of the femur underwent retrograde intramedullary nailing. An open reduction and additional fixation using a shape memory alloy ring were used in 3 of them in whom a closed reduction was not successful. The clinical and radiographic findings were reviewed retrospectively in 7 patients (8 knees), excluding 2 who were unavailable for a follow-up assessment due to death. The mean follow-up period was 39 months (range, 24 to 82 months). The union and alignment of the fracture were assessed radiographically. The postoperative function was evaluated using Sanders' criteria. RESULTS: Radiographic union was obtained in all patients after an average of 13 weeks (range, 12 to 15 weeks) postoperatively. No postoperative infection, heterotopic ossification and component loosening were observed. After union, the coronal alignment averaged 0.1degrees valgus (range, 3.6degrees varus to 2.6degrees valgus) and the mean sagittal alignment was 1.9degrees of extension (range, 0.9degrees of flexion to 6.3degrees of extension). The mean range of motion was 103degrees (range, 90degrees to 120degrees) postoperatively. At the last follow up, there were 1 excellent, 5 good and 2 fair results according to Sanders' criteria. CONCLUSIONS: With retrograde intramedullary nailing, excellent fracture union and good functional recovery were obtained in patients with periprosthetic supracondylar fractures.