From the Department of Orthopaedics, University Hospitals Cleveland Medical Center, Cleveland, OH.
J Am Acad Orthop Surg. 2021 Jul 15;29(14):e722-e731. doi: 10.5435/JAAOS-D-20-00596.
A well-known association exists between obesity and knee osteoarthritis (OA) for both incidence and progression of the disease. However, the cartilage wear patterns in OA associated with obesity are less well studied.
The OA initiative, a prospective sample of 4,796 patients, was used for this study. After the application of inclusion and exclusion criteria, patients were stratified into increasing body mass index (BMI) cohorts (BMI < 25, 25 ≤ BMI < 30, 30 ≤ BMI < 40, and 40 ≤ BMI). Knee MRIs were assessed using the semiquantitative MRI Osteoarthritis Knee Score scores. Patellofemoral (PF), medial, and lateral compartment cartilage scores were compared among BMI cohorts, controlling for confounders using linear regression models.
In total, 2,006 patients were present in our cohort, 773 men (38.5%) and 1,233 women (61.5%); the mean age was 61.7 ± 8.9 years. Increasing BMI was independently associated with increasing grades of PF wear for both right and left knees in the lateral patella facet (right knee β: 0.208, 95% confidence interval [CI]: 0.128 to 0.288, P < 0.001, left knee β: 0.147, 95% CI: 0.056 to 0.237, P = 0.002), medial femoral trochlea (right knee β: 0.135, 95% CI: 0.065 to 0.204, P < 0.001, left knee β: 0.142, 95% CI: 0.063 to 0.221, P < 0.001), and lateral femoral trochlea (right knee β: 0.163, 95% CI: 0.093 to 0.232, P < 0.001, left knee β: 0.147, 95% CI: 0.067 to 0.226, P < 0.001). For the right knee, increasing BMI was associated with medial compartment wear in the posterior femoral area (β: 0.070, 95% CI: 0.015 to 0.126, P = 0.013) and lateral compartment wear in the central tibial area (β: 0.070, 95% CI: 0.002 to 0.138, P = 0.045). For the left knee, increasing BMI was associated with medial compartment wear in the central femoral area (β: 0.093, 95% CI: 0.016 to 0.171, P = 0.018).
Obesity is preferentially associated with increasing cartilage wear in the PF compartment in comparison to the tibiofemoral compartment. Physical therapy and exercise programs that promote weight loss should be modified to decrease forces on the PF joint.
肥胖与膝骨关节炎（OA）的发病和进展之间存在着明显的关联。然而，与肥胖相关的 OA 的软骨磨损模式研究得还不够充分。
本研究使用了前瞻性样本 4796 例患者的 OA 计划。在应用纳入和排除标准后，患者被分为体质量指数（BMI）递增队列（BMI<25、25≤BMI<30、30≤BMI<40 和 40≤BMI）。使用半定量 MRI 骨关节炎膝关节评分（MRI Osteoarthritis Knee Score）评估膝关节 MRI。在控制混杂因素的情况下，使用线性回归模型比较 BMI 队列之间的髌股（patellofemoral，PF）、内侧和外侧关节腔软骨评分。
在我们的队列中，共有 2006 例患者，其中 773 例男性（38.5%），1233 例女性（61.5%）；平均年龄为 61.7±8.9 岁。BMI 的增加与右膝和左膝外侧髌骨面的 PF 磨损程度的增加独立相关（右膝β：0.208，95%置信区间[CI]：0.128 至 0.288，P<0.001，左膝β：0.147，95%CI：0.056 至 0.237，P=0.002）、内侧股骨滑车（右膝β：0.135，95%CI：0.065 至 0.204，P<0.001，左膝β：0.142，95%CI：0.063 至 0.221，P<0.001）和外侧股骨滑车（右膝β：0.163，95%CI：0.093 至 0.232，P<0.001，左膝β：0.147，95%CI：0.067 至 0.226，P<0.001）。对于右膝，BMI 的增加与股骨后区的内侧关节腔磨损（β：0.070，95%CI：0.015 至 0.126，P=0.013）和胫骨中央区的外侧关节腔磨损（β：0.070，95%CI：0.002 至 0.138，P=0.045）有关。对于左膝，BMI 的增加与股骨中央区的内侧关节腔磨损有关（β：0.093，95%CI：0.016 至 0.171，P=0.018）。
肥胖与髌股关节腔的软骨磨损程度增加有关，而与胫股关节腔的软骨磨损程度增加相比则不那么明显。应修改促进减肥的物理治疗和运动计划，以减少髌股关节的受力。
