II Clinica Ortopedica, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1, 40137, Bologna, Italy.
Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
J Med Case Rep. 2024 Aug 31;18(1):400. doi: 10.1186/s13256-024-04739-1.
Distal femur osteotomies are a well known and valuable treatment option to manage valgus malalignment with unicompartmental arthritis. Early postoperative complications are well known, and risk factors, such as pulmonary diseases, smoke, high dependent functional status, and body mass index, have been studied, but no study is available about osteotomies when gait is abnormal because of neurodegenerative conditions or when mineral density is below the normal rate.
We report the case of a 44 year-old female Mediterranean patient who underwent a biplanar distal femur opening wedge osteotomy surgery following a lateral meniscus total removal, which led to the subsequent development of lateral compartment osteoarthritis and pain, despite general comorbidities, such as multiple sclerosis. Additionally, 2 months later a supracondylar femur fracture above the previously applied Tomofix plate was reported. Fracture was treated by applying a LCP condylar 16 hole (336 mm) plate, a structural fibular graft, and strut fibular graft on the opposite side.
The overall aim of this case report is to provide a lesson to surgeons who want to perform a realignment surgery of the lower limb in patients with abnormal gait. Not only mechanical axes are to be considered, but also bone density, patient's gait, and load force distribution along the bone stock. Emerging literature on three-dimensional cutting guides fails to account for these factors, thus promoting a standardized approach to surgery across all patients. The present case highlights a patient with low bone density and abnormal force distribution resulting from a pathologic neurodegenerative gait. In such cases, treatment decisions must carefully consider the biomechanical vulnerabilities of the native bone and the distribution of vector forces. These conditions must lead the choice toward a longer plate if an osteotomy is indicated, because surgery is more likely to fail.
对于单间室关节炎伴外翻畸形，股骨远端截骨术是一种众所周知且有效的治疗选择。术后早期并发症众所周知，并且已经研究了诸如肺部疾病、吸烟、高依赖功能状态和体重指数等风险因素，但尚无关于因神经退行性疾病导致步态异常或骨密度低于正常水平而行截骨术的研究。
我们报告了一例 44 岁的地中海女性患者的病例，她在外侧半月板全切除术后接受了双平面股骨远端开口楔形截骨术，随后出现外侧间室骨关节炎和疼痛，尽管存在多发性硬化症等一般合并症。此外，2 个月后，报告了先前应用 Tomofix 板上方的髁上股骨骨折。通过应用 LCP 髁 16 孔（336 毫米）板、腓骨结构性移植物和对侧支柱腓骨移植物治疗骨折。
本病例报告的总体目的是为希望对步态异常的患者进行下肢矫正手术的外科医生提供一个教训。不仅要考虑机械轴，还要考虑骨密度、患者的步态和沿骨库存分布的负荷力。关于三维切割导向器的新出现文献没有考虑到这些因素，因此促进了对所有患者的标准化手术方法。本病例突出了一位骨密度低且由于病理性神经退行性步态导致力分布异常的患者。在这种情况下，治疗决策必须仔细考虑固有骨的生物力学脆弱性和矢量力的分布。如果需要截骨术，这些情况必须导致选择更长的板，因为手术更有可能失败。
