股骨近端防旋髓内钉治疗老年股骨转子间骨折内固定失败原因分析

Failure analysis of proximal femoral nail antirotation in treatment of geriatric intertrochanteric fractures

目的分析股骨近端防旋髓内钉(proximal femoral nail antirotation,PFNA)内固定治疗老年股骨转子间骨折的失败原因。方法回顾分析2015年5月-2017年6月采用PFNA内固定治疗的136例股骨转子间骨折患者临床资料。其中男106例,女30例;年龄60~80岁,平均75.5岁。骨折按Evans-Jensen分型,Ⅰ型45例,Ⅱ型50例,Ⅲ型23例,Ⅳ型13例,Ⅴ型5例。受伤至手术时间2~4d,平均3d。根据手术前后X线片,总结PFNA内固定失败患者的骨折类型(稳定型和不稳定型)、骨折复位质量(根据Baumgaertner等的标准评定)、外侧壁及后内侧骨皮质完整性,分析失败原因。结果136例患者术后均获随访,随访时间7~18个月,平均13.6个月。术后发生PFNA内固定失败17例(12.5%),其中稳定型骨折3例、不稳定型骨折14例;骨折复位质量优2例、良5例、差10例;外侧壁完整10例、缺损7例;后内侧骨皮质完整9例、缺损8例。内固定失败原因分析:(1)股骨转子间后内侧骨皮质缺失致术后12周出现髋内翻8例,其中7例继续非负重观察,术后6个月骨折愈合;1例术后发生螺旋刀片切出,行人工全髋关节置换术。(2)外侧壁缺损致内固定失败7例,其中2例术后发生螺旋刀片退钉,非负重观察,于骨折愈合后取出内固定物;2例发生旋转畸形,旋转均不超过15°,未作特殊治疗,术后6个月骨折端愈合;3例术中致股骨转子间外侧壁破裂,非负重观察,术后6个月骨折愈合。(3)术中主钉远端螺钉锁偏2例,其中1例为术中及时发现并重新植钉,1例于术后3d摄片发现并伴股骨干裂隙骨折,均非负重观察,术后1年后骨折端愈合。结论股骨转子间骨折类型(尤其是不稳定型骨折)、股骨近端外侧壁完整性、后内侧骨皮质是否缺损是PFNA治疗老年股骨转子间骨折成败的内在危险因素,术中对外侧壁有效保护及良好的骨折复位质量是术者必须重视的外在因素。

Objective To analyze the failure factors of proximal femoral nail antirotation(PFNA) in the treatment of geriatric intertrochanteric fractures. Methods The clinical data of 136 cases of intertrochanteric fracture treated with PFNA internal fixation between May 2015 and June 2017 were retrospectively analyzed. There were 106 males and 30 females, aged from 60 to 80 years, with an average age of 75.5 years. According to Evans-Jensen classification, there were 45 cases of type Ⅰ, 50 cases of type Ⅱ, 23 cases of type Ⅲ, 13 cases of type Ⅳ, and 5 cases of type Ⅴ. The time from injury to operation was 2-4 days, with an average of 3 days. According to the X-ray films before and after operation, the fracture types(stable and unstable), reduction quality(according to Baumgaertner’s criteria), integrity of lateral wall and posteromedial cortex of the patients with failure of PFNA internal fixation were summarized, and the causes of failure were analyzed. Results All the 136 patients were followed up 7-18 months(mean, 13.6 months). There were 17 cases(12.5%) of PFNA internal fixation failure after operation, including 3 cases of stable fracture and 14 cases of unstable fracture;the quality of fracture reduction was excellent in 2 cases, good in 5 cases, and poor in 10 cases;10 cases with complete lateral wall and 7 cases with defect;9 cases with complete posteromedial cortex and 8 cases with defect. Reasons for failure of internal fixation:① There were 8 cases of coxa varus at 12 weeks after operation due to the loss of posteromedial cortex of femoral intertrochanteric, 7 of them continued non-weight-bearing observation and fracture healed at 6 months after operation;1 case underwent total hip arthroplasty with spiral blade excision after operation.②There were 7 cases of internal fixation failure caused by lateral wall defect, including 2 cases of screw blade retraction,continued non-weight-bearing observation, and removed the internal fixator after fracture healing;2 cases of malunion of rotation with the rotation of no more than 15°, fracture healed at 6 months after operation without special treatment;and3 cases of rupture of lateral intertrochanteric wall during operation, continued non-weight-bearing observation and fracture healed at 6 months after operation.③ The distal locking of the main screw was deviated in 2 cases during operation. One of them was found and replanted in time during operation, and 1 case was found with fracture of femoral shaft on 3 days after operation, following 1 year of non-weight-bearing observation and fracture ending healing.Conclusion The types of intertrochanteric fractures(especially unstable fractures), the integrity of the proximal lateral wall of femur, and the defect of the posteromedial cortex are the internal risk factors for the success or failure of PFNA in the treatment of geriatric intertrochanteric fractures. The effective protection of the lateral wall during operation and the good quality of fracture reduction are the external factors that must be paid attention to.