RESUMO
PURPOSE: Calcaneal fractures (CFs) are rare but potentially debilitating injuries. Apart from the open, far lateral or sinus tarsi approach, operative treatment can be performed minimally invasive and percutaneously with intramedullary nailing. In this study, we sought to investigate the functional outcome of severe CFs treated with the C-Nail® implant. METHODS: Twenty-two CFs (9 × Sanders III and 8 × Sanders IV), operated between 2016 and 2019, were followed up with a mean duration of 36 (± 11) months. The AOFAS score, pre- and postoperative Böhler angles, wound healing disorders, and patient-reported outcome measures (PROMs) like pain levels and return to work/sport levels were assessed. RESULTS: The mean AOFAS score was 72.0 (± 9.8). Four patients sustained wound healing disorders, yet no implant-associated surgical revision was required. Fifty percent of patients were pain-free within 1 year. Within 1 year, about 50% of the patients could return to sports, and about 80% of the patients could return to work. PROMs and functional results align with those from other implants reported in the literature. CONCLUSION: Intramedullary nailing of severe CFs with the C-Nail® implant can be considered a safe treatment alternative that yields acceptable results at mid-terms.
RESUMO
BACKGROUND: Displaced transverse patellar fractures require open reduction and internal fixation. State-of-the-art stabilization techniques are tension band wiring (TBW) using Kirschner wires or cannulated screws. These techniques are associated with high rates of secondary fracture displacement, implant migration, implant prominence, wound-healing disturbances, and the need for implant removal. Recently, a locked intraosseous patellar nail prototype was developed. The aim of the present study was to investigate the biomechanical performance of this nail compared with TBW using cannulated screws. METHODS: Seven paired fresh-frozen human cadaveric knees were stripped of all soft tissues except the extensor apparatus. A transverse osteotomy was created to simulate an OTA/AO type 34-C1 transverse patellar fracture. The specimen pairs were randomly assigned to be fixed with TBW using cannulated screws or with the new intraosseous nail. Each specimen was cyclically tested for 5,000 cycles by pulling on the quadriceps tendon and simulating active knee extension and passive knee flexion within the range from 90° of flexion to full knee extension. Anterior and articular margin displacement of the fracture as well as interfragmentary rotation around the mediolateral axis were investigated with optical motion tracking after 100, 500, 1,000, 2,500, and 5,000 test cycles. RESULTS: Within the respective 5 testing-cycle time points evaluated, the articular margin displaced on average 68%, 60%, 72%, 76%, and 81% less after intraosseous nailing compared with TBW. Whereas the difference remained nonsignificant after 100 and 500 cycles (p ≥ 0.116), a trend toward significance was observed after 1,000 cycles (p = 0.063), which became significant after 2,500 and 5,000 cycles (p ≤ 0.043). CONCLUSIONS: From a biomechanical point of view, the locked intraosseous patellar nail may be an alternative to TBW using cannulated screws because of the higher interfragmentary stability provided at the articular fracture site. CLINICAL RELEVANCE: A locked patellar nail for transverse patellar fractures achieved a stable osteosynthetic construct that may reduce hardware-associated complications because of its intraosseous positioning.
