Katanbaf Reza M, Swartz Gabrielle N, Weiss Joshua, Mont Michael A, Delanois Ronald E, Nace James
The Rubin Institute for Advanced Orthopedics, Lifebridge Health, Sinai Hospital of Baltimore, Baltimore, Maryland.
St George's University, University Centre Grenada, True Blue, West Indies, Grenada.
J Arthroplasty. 2025 Jun 5. doi: 10.1016/j.arth.2025.05.113.
Body mass index (BMI) cutoffs remain controversial in unicompartmental knee arthroplasty (UKA), as one must balance complication risks and the need for conversion to total knee arthroplasty (TKA). This study aimed to analyze the impact of BMI, stratified by obesity class, on: (1) 90-day and 1- and 2-year postoperative complications; and (2) the 2- and 5-year TKA conversion rates.
We used a national, all-payer database to identify 4,823 patients who underwent UKA from 2016 to 2022 who had a history of osteoarthritis. Patients who had malignancy or trauma were excluded. Patients were stratified by BMI into four cohorts: BMI 20 to 29.9 (n = 923), BMI 30 to 34.9 (n = 1,404), BMI 35 to 39.9 (n = 1,052), and BMI 40+ (n = 698). We analyzed: (1) demographics and comorbidities, (2) complication rates at 90 days, and 1 and 2 years; and (3) rates of conversion to TKA at 5 years in patients who have a 5-year follow-up.
Higher BMI was associated with younger age and increased incidence of diabetes. No differences were seen in complication rates at 90 days, and 1 and 2 years between BMI groups. Unadjusted odds ratios (ORs) demonstrated increased 2-year TKA conversion risk among BMI groups 35 to 39.9 (OR 1.34, 95% confidence interval [CI] 1.02 to 1.78) and 40+ (OR 1.61, 95% CI 1.20 to 2.18). However, these were not significant following multivariate regressions. The highest odds were in the BMI 40+ group (OR 1.52, 95% CI 1.00 to 2.33), though still not statistically significant. Subgroup analysis of patients who had a 5-year follow-up showed no differences in TKA conversion rates.
Obese patients across BMI subclasses demonstrated no increased risk of postoperative complications after UKA. At 5 years, obese patients demonstrated no significant risk of conversion to TKA.
在单髁膝关节置换术（UKA）中，体重指数（BMI）的临界值仍存在争议，因为必须平衡并发症风险和转为全膝关节置换术（TKA）的必要性。本研究旨在分析按肥胖类别分层的BMI对以下方面的影响：（1）术后90天以及1年和2年的并发症；（2）2年和5年的TKA转换率。
我们使用一个全国性的全付费者数据库，识别出2016年至2022年期间接受UKA且有骨关节炎病史的4823例患者。排除有恶性肿瘤或创伤史的患者。根据BMI将患者分为四个队列：BMI 20至29.9（n = 923），BMI 30至34.9（n = 1404），BMI 35至39.9（n = 1052），以及BMI 40及以上（n = 698）。我们分析了：（1）人口统计学和合并症，（2）90天、1年和2年时的并发症发生率；以及（3）有5年随访的患者在5年时转为TKA的发生率。
较高的BMI与较年轻的年龄以及糖尿病发病率增加相关。BMI组之间在90天、1年和2年时的并发症发生率未见差异。未调整的优势比（OR）显示，BMI 35至39.9组（OR 1.34，95%置信区间[CI] 1.02至1.78）和BMI 40及以上组（OR 1.61，95% CI 1.20至2.18）在2年时TKA转换风险增加。然而，多变量回归后这些差异无统计学意义。最高的优势比在BMI 40及以上组（OR 1.52，95% CI 1.00至2.33），尽管仍无统计学意义。对有5年随访的患者进行亚组分析显示TKA转换率无差异。
UKA术后，各BMI亚类的肥胖患者术后并发症风险均未增加。在5年时，肥胖患者转为TKA的风险无显著增加。
