Fixed-angle plates in patella fractures - a pilot cadaver study.

OBJECTIVE: Modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring are currently the fixation of choice for patellar fractures. Failure of fixation, migration of the wires, postoperative pain and resulting revision surgery, however, are not uncommon. After preliminary biomechanical testing of a new fixed-angle plate system especially designed for fixation of patella fractures the aim of this study was to evaluate the surgical and anatomical feasibility of implanting such a plate-device at the human patella. METHODS: In six fresh unfixed female cadavers without history of previous fractures around the knee (average age 88.8 years) a bilateral fixed-angle plate fixation of the patella was carried out after previous placement of a transverse central osteotomy. Operative time, intraoperative problems, degree of retropatellar arthritis (following Outerbridge), quality of reduction and existence of any intraarticular screw placement have been raised. In addition, lateral and anteroposterior radiographs of all specimens were made. RESULTS: Due to the high average age of 88.8 years no patella showed an unimpaired retropatellar articular surface and all were severely osteoporotic, which made a secure fixation of the reduction forceps during surgery difficult. The operation time averaged 49 minutes (range: 36-65). Although in postoperative X-rays the fracture gap between the fragments was still visible, the analysis of the retropatellar surface showed no residual articular step or dehiscence > 0.5 mm. Also in a total of 24 inserted screws not one intraarticular malposition was found. No intraoperative complications were noticed. CONCLUSIONS: Osteosynthesis of a medial third patella fracture with a bilateral fixed-angle plate-device is surgically and anatomically feasible without difficulties. Further studies have to depict whether the bilateral fixed-angle plate-osteosynthesis of the patella displays advantages over the established operative procedures.

[Femoral fracture in congenital femoral deficiency. A therapeutic challenge?]. / Femurfraktur bei kongenitalem Femurdefekt. Eine therapeutische Herausforderung?

There are no reports in the literature about femoral fractures in adults with congenital femoral deficiency. We report on a femoral fracture in a 60-year-old patient with congenital femoral deficiency. Despite early difficulties in mobilisation and delayed union after an angle-stable plate osteosynthesis, full weight bearing was reached after 8 months. The treatment of fractures in combination with congenital femoral deficiency remains difficult and depends on the extent of the defect, the complexity of the fracture, and associated anomalies. The objective of the often demanding operative treatment of a femoral fracture in combination with a congenital femoral deficiency should be reestablishment of the patient's walking ability.

[Dynamic cerclage wiring of patellar fractures. Complications and midterm functional results]. / Die Zuggurtungsosteosynthese nach Patellafraktur. Komplikationen und mittelfristige klinische Ergebnisse.

BACKGROUND: Preserving the patella and its accurate anatomic reduction after fracture is extremely important to avoid retropatellar arthrosis. METHODS: The data of 50 patients with patellar fractures treated by cerclage wiring was analyzed in relation to complications. In addition, 37 patients were called in for follow-up examination, and the functional results were assessed according to the Tegner and Lyshom scores. RESULTS: Minor complications occurred in 50% and major complications in 30% of cases. Despite the high complication rate, 70% of the examined patients revealed excellent to good objective or subjective results, while 10% of the patients showed poor results. No correlation existed between the fracture severity and the complication rate on the one hand or the postoperative objective outcome on the other hand. CONCLUSION: Operative treatment of patellar fractures is still demanding. Although most of the examined patients were quite satisfied and demonstrated excellent to good results, the high complication rate is reason to take other methods of internal fixation into consideration to further optimize results.