Nagayama Kyohei, Shishido Takaaki, Ishida Tsunehito, Iwasa Norihiko, Nishikawa Yohei, Tateiwa Toshiyuki, Masaoka Toshinori, Yamamoto Kengo
Orthopedics, Tokyo Medical University Hospital, Tokyo, JPN.
Orthopedic Surgery, Tokyo Medical University Hospital, Tokyo, JPN.
Cureus. 2024 Oct 24;16(10):e72282. doi: 10.7759/cureus.72282. eCollection 2024 Oct.
Total knee arthroplasty (TKA) is expected to improve knee pain and enable patients to regain the ability to walk, but the associations between preoperative and postoperative changes in body composition, muscle strength, and activity remain unclear. In this study, we investigated the association between changes in body composition before and after TKA surgery, the recovery process of muscle strength, and changes in activity, as well as the effects of obesity on TKA.
A total of 124 patients with unilateral knee osteoarthritis (OA) who underwent TKA were retrospectively evaluated. Body weight (BW) and body composition (body fat percentage (BFP) and diseased limb muscle mass (DLMM)), measured by bioelectrical impedance analysis, quadriceps muscle strength (QMS), measured using the isometric muscle strength meter, number of steps (NOS), and Japanese Orthopaedic Association (JOA) OA knee diseases treatment outcome criteria (JOA score) before the operation, at postoperative six months (PO6M), and at postoperative one year (PO1Y) after the operation were investigated and compared between the non-obese (BMI < 25 kg/m) group, including underweight (<18.5 kg/m) and normal weight patients (18.5 to 24.9 kg/m), and obese (BMI ≥ 25 kg/m) group, including overweight (25.0 to 29.9 kg/m) or obese patients (≥30.0 kg/m).
In all patients, JOA scores significantly improved from 59.7 preoperatively to 81.2 at PO6M, and 82.7 at PO1Y (both p < 0.01). QMS significantly increased from 112.4 N preoperatively to 144.0 N at PO6M, and 151.0 N at PO1Y (both p < 0.01). On the other hand, there was no significant change in BW, BFP, NOS, and DLMM. A comparison between the obese (n = 76) and non-obese (n = 48) groups demonstrated that there was no significant difference in JOA scores preoperatively, but scores at PO1Y were significantly higher in the non-obese group (p < 0.01), and QMS increased significantly postoperatively in both groups, but the enlargement rate at PO1Y was 1.4% in the obese group versus 10.4% in the non-obese group (p = 0.04).
In the body composition of TKA patients, BW, BFP, and DLMM/BW did not change significantly from preoperatively to PO1Y, but QMS and JOA scores showed significant improvement at PO6M and PO1Y compared to preoperatively. The obese patients showed less improvement in JOA scores than non-obese patients, and the rate of increase in QMS at PO1Y was smaller, suggesting that rehabilitation focusing on muscle-strengthening training is necessary even at PO6M, especially in obese patients.
全膝关节置换术（TKA）有望改善膝关节疼痛并使患者恢复行走能力，但术前与术后身体成分、肌肉力量和活动变化之间的关联仍不明确。在本研究中，我们调查了TKA手术前后身体成分变化、肌肉力量恢复过程和活动变化之间的关联，以及肥胖对TKA的影响。
对124例行TKA的单侧膝关节骨关节炎（OA）患者进行回顾性评估。通过生物电阻抗分析测量体重（BW）、身体成分（体脂百分比（BFP）和患侧肢体肌肉质量（DLMM）），使用等长肌力计测量股四头肌力量（QMS），记录术前、术后6个月（PO6M）和术后1年（PO1Y）的步数（NOS）以及日本骨科协会（JOA）OA膝关节疾病治疗结果标准（JOA评分），并在非肥胖（BMI < 25 kg/m²）组（包括体重过轻（<18.5 kg/m²）和正常体重患者（18.5至24.9 kg/m²））与肥胖（BMI≥25 kg/m²）组（包括超重（25.0至29.9 kg/m²）或肥胖患者（≥30.0 kg/m²））之间进行比较。
所有患者中，JOA评分从术前的59.7显著提高到PO6M时的81.2，PO1Y时为82.7（均p < 0.01）。QMS从术前的112.4 N显著增加到PO6M时的144.0 N，PO1Y时为151.0 N（均p < 0.01）。另一方面，BW、BFP、NOS和DLMM无显著变化。肥胖组（n = 76）和非肥胖组（n = 48）之间的比较表明，术前JOA评分无显著差异，但非肥胖组PO1Y时的评分显著更高（p < 0.01），两组术后QMS均显著增加，但肥胖组PO1Y时的增大率为1.4%，而非肥胖组为10.4%（p = 0.04）。
在TKA患者的身体成分中，从术前到PO1Y，BW、BFP和DLMM/BW无显著变化，但与术前相比，QMS和JOA评分在PO6M和PO1Y时显著改善。肥胖患者的JOA评分改善程度低于非肥胖患者，且PO1Y时QMS的增加率较小，这表明即使在PO6M时，尤其是肥胖患者，也有必要进行以肌肉强化训练为重点的康复治疗。
