Kwon Hyuck Min, Han Chang Dong, Yang Ick-Hwan, Lee Woo-Suk, Kim Chan Woo, Park Kwan Kyu
Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
Orthop Res Rev. 2020 Apr 5;12:53-60. doi: 10.2147/ORR.S243444. eCollection 2020.
Being underweight has never been studied in relation to the radiologic and clinical outcomes of total knee arthroplasty (TKA) in elderly patients. The aim of this study was to determine the effect of being underweight on TKA radiological and clinical outcomes and to investigate whether being underweight influences postoperative complications compared to normal body mass index (BMI) in elderly patients.
A total of 118 female patients aged 65 years or older with BMI < 25 kg/m who underwent primary TKA were divided into two groups based on BMI: group A: 18.5 kg/m < BMI < 25 kg/m; group B: BMI < 18.5 kg/m. The radiologic and clinical outcomes were evaluated at follow-up of 6, 12, and 24 months after surgery such as the hip-knee-ankle angle, the American Knee Society (AKS) score, Western Ontario and McMaster University score (WOMAC), and patellofemoral (PF) scale. Moreover, postoperative complications during follow-up were investigated.
Preoperative clinical scores did not differ significantly between the two groups. Postoperative WOMAC pain (1.8 ± 1.9 versus 3.4 ± 2.6, p = 0.02), WOMAC function (12.4 ± 8.1 versus 16.5 ± 8.5, p = 0.012) and PF scales (26.1 ± 3.6 versus 23.7 ± 4.1, p = 0.002) were worse in the underweight group at 12 and 24 months after surgery. The frequency of postoperative complications did not differ significantly between groups. In multivariate linear regression analysis, underweight patient group was significantly associated with worse postoperative WOMAC and PF scores (p = 0.002, 0.005).
Although postoperative complications of TKA did not differ between groups, underweight patients had worse clinical outcomes of TKA compared to patients with normal BMI in elderly patients. Therefore, care should be taken when performing TKA in elderly underweight patients.
体重过轻与老年患者全膝关节置换术（TKA）的放射学和临床结果之间的关系从未被研究过。本研究的目的是确定体重过轻对TKA放射学和临床结果的影响，并调查与正常体重指数（BMI）的老年患者相比，体重过轻是否会影响术后并发症。
共有118名年龄在65岁及以上、BMI<25kg/m²且接受初次TKA的女性患者根据BMI分为两组：A组：18.5kg/m²<BMI<25kg/m²；B组：BMI<18.5kg/m²。在术后6、12和24个月的随访中评估放射学和临床结果，如髋-膝-踝角、美国膝关节协会（AKS）评分、西安大略和麦克马斯特大学评分（WOMAC）以及髌股（PF）量表。此外，还调查了随访期间的术后并发症。
两组术前临床评分无显著差异。术后12个月和24个月时，体重过轻组的WOMAC疼痛评分（1.8±1.9对3.4±2.6，p=0.02）、WOMAC功能评分（12.4±8.1对16.5±8.5，p=0.012）和PF量表评分（26.1±3.6对23.7±4.1，p=0.002）更差。两组术后并发症的发生率无显著差异。在多变量线性回归分析中，体重过轻患者组与术后更差的WOMAC和PF评分显著相关（p=0.002，0.005）。
虽然两组TKA的术后并发症无差异，但与正常BMI的老年患者相比，体重过轻的患者TKA临床结果更差。因此，在老年体重过轻患者中进行TKA时应谨慎。
