Fujita Kenji, Sawaguchi Takeshi, Goshima Kenichi, Shigemoto Kenji, Iwai Shintaro
Department of Orthopedic Surgery and Joint Reconstructive Surgery, Toyama Municipal Hospital, 2-1 Imaizumi Hokubu-machi, Toyama, 939-8511, Japan.
Department of Orthopedic Surgery, Ishikawa Prefectural Central Hospital, 2-1 Kuratsukihigashi, Kanazawa, Ishikawa, 920-8530, Japan.
Arch Orthop Trauma Surg. 2023 Mar;143(3):1175-1183. doi: 10.1007/s00402-021-04212-4. Epub 2021 Oct 16.
The purpose of this study was to examine the influence of lateral hinge fractures in medial closing-wedge distal femoral osteotomy (MCWDFO) on bone union.
Twenty-one patients were followed-up for more than 1 year after MCWDFO. The incidence and type of hinge fracture, as well as the course of bone healing, were investigated. Slow healing was defined as bone union was not obtained until 3 months after surgery.
Hinge fractures were observed in 12 cases (57%). There were three types of hinge fractures. Type 1: the lateral cortex was completely cut through (4 cases), type 2: the osteotomy line was too proximal (6 cases), and type 3: the hinge point was significantly medial (2 cases). There was a significant difference in the mean correction angles between hinge fracture and no-fracture cases, with the mean angles being 13.8 ± 4.0° and 9.6 ± 3.1°, respectively. Sixty-seven percent (8/12) of cases with hinge fractures developed slow healing. Among the hinge fracture cases, when there was no displacement of the hinge fracture and good contact with the anterior flange, 40% (2/5) of cases developed slow healing. If there was displacement of the hinge or no contact of the anterior flange, 86% (6/7) of cases developed slow healing. In contrast, only 11% (1/9) of subjects who did not have a hinge fracture, developed slow healing. In 67% (6/9) of cases with slow healing, a correction loss of 2° or greater (average: 4.3 degrees valgus) was observed. There were no cases of non-union. Clinical outcomes at 1 year showed no significant difference between the groups with and without hinge fractures.
There is a very high risk of hinge fracture in patients undergoing MCWDFO. Hinge fractures often lead to slow healing and a loss of correction. We recommend the endpoint of the distal lateral cortex of the femur as the ideal hinge point for the prevention of hinge fractures. Bone union is obtained slowly in even all hinge fracture cases without revision surgery. Consequently, surgical results are not affected by the occurrence of hinge fracture at 1 year.
本研究旨在探讨股骨远端内侧闭合楔形截骨术（MCWDFO）中外侧铰链骨折对骨愈合的影响。
对21例行MCWDFO术后的患者进行了1年以上的随访。调查铰链骨折的发生率、类型以及骨愈合过程。愈合缓慢定义为术后3个月仍未实现骨愈合。
12例（57%）观察到铰链骨折。铰链骨折有三种类型。1型：外侧皮质完全断裂（4例），2型：截骨线过于靠近近端（6例），3型：铰链点明显偏内侧（2例）。铰链骨折病例与无骨折病例的平均矫正角度存在显著差异，平均角度分别为13.8±4.0°和9.6±3.1°。67%（8/12）的铰链骨折病例出现愈合缓慢。在铰链骨折病例中，当铰链骨折无移位且与前侧骨皮质接触良好时，40%（2/5）的病例出现愈合缓慢。如果铰链有移位或与前侧骨皮质无接触，则86%（6/7）的病例出现愈合缓慢。相比之下，无铰链骨折的患者中只有11%（1/9）出现愈合缓慢。在67%（6/9）的愈合缓慢病例中，观察到矫正丢失2°或更大（平均：4.3°外翻）。无骨不连病例。1年时的临床结果显示，有铰链骨折组与无铰链骨折组之间无显著差异。
接受MCWDFO的患者发生铰链骨折的风险非常高。铰链骨折常导致愈合缓慢和矫正丢失。我们建议将股骨远端外侧皮质的终点作为预防铰链骨折的理想铰链点。即使在所有未进行翻修手术的铰链骨折病例中，骨愈合也很缓慢。因此，1年时手术结果不受铰链骨折发生的影响。
