The augment of the stability in leaving original internal fixation with multidimensional cross locking plate through femoral anterior approach for aseptic femoral nonunion

Background: Intramedullary nail fixation is the gold standard for the treatment of fresh femoral shaft fractures. Although the incidence of nonunion has decreased significantly, it still occurs from time to time, reaching 1-10%. The main reason was thought as the insecure anti-rotational stability. A lateral locking plate (LP), leaving the nail in situ, was applied to the fracture site to counter the rotational instability. To achieve much more stability, massive surgical exposure was needed for a longer plate or more uni-cortical screws fixation. To solve this problem, a new designed Multidimensional Cross Locking Plate (MDC-LP) was designed. The purpose of this study is to investigate its clinical advantage compared to lateral LP. Methods: In this retrospective study, forty-nine consecutive aseptic femoral nonunion from January 2015 to October 2019 were randomly assigned to treatment with MDC-LP (group A) and lateral LP (group B) and were analyzed after a minimum 1-year follow-up. The demographic data and surgical information were all compared. Functional outcomes were evaluated by Lower Extremity Functional Scale (LEFS) at last follow-up. Results: There are no significant differences in the mean age, gender, BMI, time since injury, initial fracture (close/open), nonunion type or location between groups. A 2-months advantage in the time to union was seen in the patients treated with MDC-LP (4.09 months versus 6.8 months in the lateral LP: p= 0.000). All the patients in group A at 9 months postoperatively have bone union but 91% in group B (p=0.449), but all the patients in group A at 6 months have bone healing but 63.6% in group B (p=0.001). More bicortical screw fixation was seen in the treatment with MDC-LP (7 versus 2 in the lateral LP: p= 0.000). Less blood transfusion during hospitalization in group A (222ml versus 745ml in group B: p=0.000). In addition, smaller incision and shorter plate was used in group A compared to those in group B. Better functional outcome in the LEFS was seen in the patients treated with MDC-LP (73 versus 62 in group B: P=0.000). In group A, no complications were observed. However, in group B, 5/22 cases suffered superficial infection and 1/22 patients had persistent nonunion. Conclusions: For the treatment of femoral nonunion, new designed MDC-LP may be a good option to enhance antirotation stability with retention of primary nailing by providing much more bicortical screw fixation and allow to be placed through femoral anterior approach with faster healing, less surgical trauma, and satisfactory functional outcome.

【背景】髓内钉固定是治疗新鲜股骨干骨折的金标准。尽管骨不连（nonunion）的发生率已显著降低，但仍时有发生，发生率达1%~10%，既往认为其主要原因是抗旋转稳定性不足。临床曾采用保留原位髓内钉的侧方锁定钢板（LP）固定骨折部位，以对抗旋转不稳定；但为获得更高稳定性，需通过大范围手术暴露放置更长钢板或采用更多单皮质螺钉固定。为解决这一问题，本研究团队设计了一款新型多维交叉锁定钢板（MDC-LP）。本研究旨在探讨该钢板相较于侧方锁定钢板的临床优势。

【方法】本回顾性研究纳入2015年1月至2019年10月期间连续收治的49例无菌性股骨骨不连患者，将其随机分为MDC-LP组（A组）与侧方锁定钢板组（B组），所有患者均完成至少1年随访并纳入分析。对比两组的人口统计学资料与手术相关信息，并于末次随访时采用下肢功能评分量表（LEFS）评估患肢功能结局。

【结果】两组患者的平均年龄、性别、身体质量指数（BMI）、受伤至手术时间、初始骨折类型（闭合/开放）、骨不连类型与部位均无显著差异。MDC-LP组患者的骨愈合时间较侧方锁定钢板组缩短2个月（4.09个月 vs 6.8个月，P=0.000）。术后9个月时，A组所有患者均达到骨性愈合，而B组仅91%患者达到骨性愈合（P=0.449）；术后6个月时，A组所有患者均实现骨愈合，而B组仅63.6%患者实现骨愈合（P=0.001）。MDC-LP组采用双皮质螺钉固定的例数更多（7例 vs 侧方锁定钢板组2例，P=0.000）。A组患者住院期间输血量更少（222ml vs B组745ml，P=0.000）。此外，与B组相比，A组手术切口更小、所用钢板更短。MDC-LP组患者的下肢功能评分量表得分更高（73分 vs B组62分，P=0.000）。A组未观察到并发症发生；而B组有5/22例患者出现浅表感染，1/22例患者存在持续性骨不连。

【结论】对于股骨骨不连的治疗，新型MDC-LP可通过提供更多双皮质螺钉固定来增强抗旋转稳定性，同时保留初始髓内钉固定，且可通过股前入路放置，具有骨愈合速度更快、手术创伤更小、功能结局满意的优势，是一种优质的治疗选择。