Department of Orthopaedic Surgery, Harborview Medical Center, University of Washington, 325 9th Avenue, Seattle, WA, 98104, USA.
Department of Orthopaedic Surgery, Stanford Hospitals and Clinics, Stanford, CA, USA.
Eur J Orthop Surg Traumatol. 2021 Oct;31(7):1421-1425. doi: 10.1007/s00590-021-02875-8. Epub 2021 Feb 15.
Excessive fracture site collapse and shortening in intertrochanteric femur fractures alter hip biomechanics and patient outcomes. The purpose of the study was to compare extent of collapse in cephalomedullary nails with blades or lag screws. We hypothesized that there would be no difference in collapse between helical blades and lag screws.
Retrospective cohort study.
Single U.S. Level I Trauma Center.
171 consecutive patients treated with cephalomedullary nails with either lag screw or blade for AO/OTA 31A1-3 proximal femur fractures and minimum 3-month follow-up.
Lag screw or helical blade in a cephalomedullary nail.
The primary outcome was fracture site collapse at 3 months.
There was a significantly higher proportion of reverse-oblique and transverse intertrochanteric femur fractures (31-A3) in the lag screw group (15/42 vs 25/129). A3 patterns were associated with more collapse. There was significantly less collapse in the blade group (median 4.7 mm, inter-quartile range 2.5-7.8 mm) than the screw group (median 8.4 mmm, inter-quartile range 3.7-11.2 mm, p 0.006). Median collapse was no different between blades and screws when comparing stable and unstable patterns. However, blades were independently associated with 2.5 mm less collapse (95%CI - 4.2, - 0.72 mm, p 0.006) and lower likelihood of excessive collapse (> 10 mm at 3 months, OR 0.3, 95% CI 0.13-0.74, p 0.007), regardless of fracture pattern.
Helical blades are independently associated with significantly less collapse than lag screws in intertrochanteric proximal femur fractures, after adjusting for unstable fracture patterns. In fracture patterns at risk for collapse, surgeons can consider use of a helical blade due to its favorable sliding properties compared to screws.
股骨转子间骨折中骨折部位过度塌陷和缩短会改变髋关节生物力学和患者预后。本研究的目的是比较髓内钉与刀片或拉力螺钉的塌陷程度。我们假设螺旋刀片和拉力螺钉之间不会有塌陷差异。
回顾性队列研究。
美国单一 1 级创伤中心。
171 例连续接受髓内钉治疗的患者，AO/OTA 31A1-3 股骨近端骨折，至少随访 3 个月，使用拉力螺钉或刀片。
髓内钉中的拉力螺钉或螺旋刀片。
拉力螺钉组中反向斜型和横断转子间股骨骨折（31-A3）的比例明显更高（15/42 比 25/129）。A3 型与更多的塌陷有关。刀片组的塌陷明显较少（中位数 4.7mm，四分位距 2.5-7.8mm），而螺钉组（中位数 8.4mm，四分位距 3.7-11.2mm，p<0.006）。比较稳定和不稳定的模式时，刀片和螺钉之间的中位塌陷没有差异。然而，刀片与 2.5mm 的塌陷减少独立相关（95%CI-4.2，-0.72mm，p<0.006），并且 3 个月时过度塌陷（>10mm）的可能性较低（OR 0.3，95%CI 0.13-0.74，p<0.007），与骨折模式无关。
在调整不稳定骨折模式后，与拉力螺钉相比，螺旋刀片独立与转子间股骨近端骨折的塌陷明显减少。在有塌陷风险的骨折模式中，由于与螺钉相比具有有利的滑动特性，外科医生可以考虑使用螺旋刀片。
