体重、肥胖与关节健康 资料

本页面由机器翻译,尚未经临床医生审核。英文版本为权威版本。

什么是

体重与关节健康密切相关。体重超标影响的不仅仅是您的膝关节。医生现在将肥胖视为一种影响全身的疾病,而不仅仅是关节承受的额外负荷 [1]。肥胖会引起炎症,随着时间推移可能磨损关节 [1]。这就是为什么较高的体重指数(BMI,即体重相对于身高的衡量指标)会增加膝关节和手部患关节炎的风险,即使是在其他方面都健康的人身上也是如此 [2]。

在手术前后,体重超标同样很重要。如果您正在考虑关节置换手术,体重是医生会考虑的众多因素之一。随着现代假体和手术技术的进步,一些与体重相关的风险已有所降低 [3]。但在另一些情况下,体重显然很重要。例如,在髋关节镜(微创)手术后,超重或肥胖的人最终需要进行全关节置换的比例高于体重正常的人 [4]。

好消息是,体重是您可以改变的 [5]。多活动身体有两方面的好处:它能保护您的心脏,而且良好的体能本身就能降低体重超标带来的部分健康风险 [6]。即使只进行少量的剧烈运动,大约每周30到35分钟,似乎也能抵消腹部肥胖与心脏病之间的关联 [7]。饮食也很重要,不过对于体重增加的主要原因究竟是吃什么还是活动太少,目前仍有争论 [8]。

医生会结合您的整体健康状况与您讨论体重问题,而不是把它当作决定一切的单一数字。

它有效吗?

坦白地说,这取决于“它”指的是什么。对于关节置换手术前的减重,有多种选择。一种用于体重管理的药物(司美格鲁肽,semaglutide)已被研究作为髋关节置换术前减重手术的替代方案,研究发现两者术后的假体存活率和并发症发生率相似 [9]。对于重度肥胖并伴有晚期膝关节炎的人,与直接进行膝关节置换相比,减重手术本身带来的总体减重幅度更大 [10]。

在运动方面,情况则不一。一项针对已接受减重(减肥)手术女性的试验发现,进行短时间高强度间歇运动并配合力量训练的人,比进行持续中等强度运动的人减重更多 [11]。至于肝脏脂肪,体重超标的成年人可能需要累计消耗大量运动能量(超过10,000 kcal)才能减少肝脏中的脂肪 [12]。

接下来谈谈手术效果。在这方面,证据总体上令人放心,但并不完美。对于膝关节置换,在一项研究环境中,BMI高于40与更多早期并发症无关 [13]。膝关节置换术后僵硬是一个常见的担忧,但在现有研究中,体重较高的人出现僵硬的情况并不比其他人更常见 [14]。对于髋关节置换,一种假体设计在重度肥胖人群中显示出良好的五年存活率 [15]。对于肩关节置换,体重与需要翻修手术的几率升高无关 [16]。

但在某些情况下,体重确实很重要。在髋关节镜手术后,肥胖人群需要进行全髋关节置换的几率是体重正常人群的两倍以上 [17]。对于单髁(部分)膝关节置换,澳大利亚关节置换登记数据显示,肥胖与较高的翻修率有关 [18]。而对于一种现代机器人辅助膝关节置换技术,肥胖仍然是假体失败的一个实际风险因素 [19]。

有几点需要注意。这类研究大多是观察性研究,也就是长期跟踪观察人群,而不是直接检验治疗方法。有些研究规模较小。不同关节和不同手术技术的结果也有差异。因此,较为公允的总结是:体重对某些风险的影响大于其他风险,医生可以和您讨论哪些风险适用于您。

风险有哪些?

体重对不同风险的影响方式各不相同,而您可能预想的一些情况并没有得到研究的支持。对于膝关节置换,在一项研究环境中,BMI高于40与更多早期并发症无关 [13]。体重较高的人在膝关节置换术后出现僵硬的情况并不更常见,因此当手术在临床上确有必要时,不应仅仅因为担心僵硬而放弃手术 [14]。对于肩关节置换,体重与血栓风险有关,但与感染无关 [20]。

有些风险确实会随着体重增加而上升。在髋关节镜手术后,肥胖人群需要进行全髋关节置换的几率是体重正常人群的两倍以上 [17]。对于单髁(部分)膝关节置换,澳大利亚关节置换登记数据显示,肥胖与较高的翻修率有关 [18]。对于一种现代机器人辅助膝关节置换技术,肥胖仍然是假体失败的一个实际风险因素 [19]。在膝关节镜手术后,肥胖和原本已存在的关节炎都会使效果较差以及转为关节置换的可能性增加 [21]。对于腿部骨折的儿童,肥胖会使住院期间的结果变差 [22]。

有几项研究结果不太明确。一项关于机器人辅助膝关节置换的研究发现,重度肥胖人群有并发症增多的趋势,但差异没有统计学意义 [23]。同一项研究还发现,BMI低于25的人关节僵硬更多 [23]。对于BMI达到或超过45的人接受非骨水泥型膝关节置换,由于病例数太少,无法得出确切结论 [24]。

医生会根据您的体重、关节情况以及拟进行的手术,与您讨论哪些风险适用于您。

这适合您吗?

对于体重超标的人,关节置换手术同样可以取得良好效果,不应仅仅因为体重而被排除在外。针对BMI高于40人群的研究发现,在一项研究环境中进行手术时,体重与早期并发症无关 [13]。当手术在临床上确有必要时,不应仅仅因为担心膝关节置换术后僵硬而放弃手术 [14]。对于髋关节置换,在BMI达到或超过40的人群中,医生做这类手术的数量多少与翻修或感染风险无关 [25]。

有些情况需要更多考虑。对于肥胖人群,单髁(部分)膝关节置换需要翻修手术的几率更高 [18]。对于BMI达到或超过45的人接受非骨水泥型膝关节置换,由于病例数太少,无法得出确切结论 [24]。

如果您想在手术前减重,请主动询问。在接受膝关节或髋关节置换之前,很少有肥胖人士获得减重帮助,无论是药物、营养服务还是减重手术 [26]。一种药物——司美格鲁肽(semaglutide)——已被研究作为髋关节置换术前的一种选择,其假体存活率和并发症发生率与减重手术相似 [9]。

正确的选择取决于您的体重、关节情况和整体健康状况。这应该是您与医生共同做出的决定。上面的风险部分介绍了体重对每种手术的意义,医生可以和您讨论其中哪些适用于您。

核心要点

体重超标会改变某些风险,但不会改变其他风险,而且不应仅仅因为体重就把您排除在关节置换手术之外。手术前减重值得主动询问,因为很少有人获得这方面的帮助 [26],而且已有一种药物被研究作为髋关节置换术前的一种选择 [9]。请抱着现实的期望:体重对某些手术的影响大于其他手术,而最需要注意的是,这类研究大多是长期跟踪观察人群,而不是直接检验治疗方法。


References
  1. Reframing Obesity in Knee Osteoarthritis: A Call for a Transdisciplinary Approach Beyond Biomechanics. *Arthroscopy*. 2026. 10.1002/arj.70051
  2. Does metabolically healthy obesity increase the risk of knee and hand osteoarthritis? A population-based cohort study. *BMC Musculoskeletal Disorders*. 2026. 10.1186/s12891-026-09495-5
  3. Obesity and Total Knee Arthroplasty Revisited: Minimal Impact on Loosening and Mechanical Failure in the Modern Era. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2026.04.031
  4. The Effect of Body Mass Index on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Matched Analysis With 10-Year Follow-up. *The American Journal of Sports Medicine*. 2026. 10.1177/03635465251400355
  5. The Role of Obesity in Pediatric Orthopedics. *JAAOS: Global Research and Reviews*. 2019. 10.5435/jaaosglobal-d-19-00036
  6. Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis. *British Journal of Sports Medicine*. 2024. 10.1136/bjsports-2024-108748
  7. Joint associations of device-measured physical activity and abdominal obesity with incident cardiovascular disease: a prospective cohort study. *British Journal of Sports Medicine*. 2023. 10.1136/bjsports-2023-107252
  8. It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet. *British Journal of Sports Medicine*. 2015. 10.1136/bjsports-2015-094911
  9. Is Semaglutide a Safer Weight-Management Option Than Bariatric Surgery for Patients Undergoing Total Hip Arthroplasty (THA)?. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2025.08.068
  10. Impact Of Prior Bariatric Surgery Versus Immediate Total Knee Arthroplasty On Knee Function Among Patients Who Have Severe Obesity And Advanced Knee Osteoarthritis: The SWIFT Trial. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2026.05.033
  11. Impact of high-intensity interval training vs. moderate-intensity continuous training combined with strength training on physical and metabolic outcomes in post-bariatric surgery patients with sarcopenic obesity. *BMC Musculoskeletal Disorders*. 2026. 10.1186/s12891-026-09722-z
  12. Effect of exercise training on liver function in adults who are overweight or exhibit fatty liver disease: a systematic review and meta-analysis. *British Journal of Sports Medicine*. 2016. 10.1136/bjsports-2016-096197
  13. Body Mass Index > 40 Is Not Correlated With Early Complications in Patients Undergoing Primary Total Joint Arthroplasty at an Ambulatory Surgical Center. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2025.08.065
  14. Obesity Severity and Stiffness After Total Knee Arthroplasty Revisited: A Contemporary Analysis of Patients Requiring Manipulation Under Anesthesia. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2026.03.080
  15. Primary Total Hip Arthroplasty in Patients Who Have Morbid Obesity: A Propensity-Weighted Analysis of Dual Mobility and Standard Fixed-Bearing Implants. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2026.03.075
  16. Revision rates between obese and nonobese total shoulder arthroplasty patients: an Australian registry data study. *Journal of Shoulder and Elbow Surgery*. 2026. 10.1016/j.jse.2025.05.036
  17. Obese Patients Treated by Hip Arthroscopy for Femoroacetabular Impingement Syndrome — 10-Year Functional Outcomes and Conversion Rates to Arthroplasty Compared With Normal-Weight Patients. *The American Journal of Sports Medicine*. 2026. 10.1177/03635465251392585
  18. Obesity is Associated with Higher Rates of Revision Following Unicompartmental Knee Arthroplasty. *Orthopaedic Journal of Sports Medicine*. 2026. 10.1177/2325967125s00336
  19. Impact of high body mass index on functionally aligned image-based robotic total knee arthroplasty: Comparable functional outcomes but higher mechanical failures. *Journal of ISAKOS*. 2025. 10.1016/j.jisako.2025.100861
  20. Overweight and Premorbid Obesity Status Correlates With Thromboembolism Risk but Not Infection After Total Shoulder Arthroplasty. *Journal of Shoulder and Elbow Surgery*. 2026. 10.1016/j.jse.2026.05.022
  21. Editorial Commentary: Obesity and Osteoarthritis Are Risk Factors for Conversion to Arthroplasty, With or Without Previous Knee Arthroscopic Surgery. *Arthroscopy*. 2025. 10.1016/j.arthro.2025.04.036
  22. Impact of pediatric obesity on surgical outcomes of lower extremity fractures: a nationwide analysis (2010–2019). *BMC Musculoskeletal Disorders*. 2026. 10.1186/s12891-025-09349-6
  23. Impact of body mass index on robotic-assisted total knee arthroplasty outcomes: A retrospective cohort analysis. *Journal of ISAKOS*. 2025. 10.1016/j.jisako.2025.100927
  24. Body Mass Index of 45 Is a Safe Cut-Off for Cementless Total Knee Arthroplasty. *The Journal of Arthroplasty*. 2025. 10.1016/j.arth.2025.12.038
  25. Effects of Doctor Volume on Outcomes Following Primary Total Hip Arthroplasty in the Morbidly Obese: An Analysis From the American Joint Replacement Registry. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2025.07.037
  26. Disparities in Preoperative Weight Loss and Obesity Treatment Before Total Joint Arthroplasty. *The Journal of Arthroplasty*. 2026. 10.1016/j.arth.2026.06.021
Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Overview

  • Obesity is a modifiable condition, and addressing it can improve the orthopaedic and overall health of children [1].
  • Each 1-unit increase in BMI is associated with a 9% reduction in osteoporosis risk [2].
  • Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients who have normal BMIs at ambulatory surgical centers [3].
  • There is confusion about the relation of energy intake and energy expenditure to obesity, with much more attention focused on diet and obesity than on physical inactivity and obesity [4].
  • The available numbers are too small to draw conclusions in patients who have a BMI ≥ 45 undergoing cementless total knee arthroplasty [5].
  • Physical activity equivalent to approximately 30–35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident cardiovascular disease [6].
  • No significant differences were observed between above-average and below-average BMI groups, and BMI was not correlated with clinical improvements following arthroscopically assisted posterior latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears [7].
  • Obesity is a systemic disease with profound inflammatory consequences on joint health, extending beyond a mechanical burden on the knee [8].
  • Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia after total knee arthroplasty [9].
  • BMI has a weak-to-moderate association with peri-incisional adiposity in primary total joint arthroplasty patients [10].
  • Very few patients who have obesity received preoperative weight loss management before total knee arthroplasty or total hip arthroplasty via medications, nutrition services, or bariatric surgery regardless of sex or socioeconomic status [11].
  • The WHO obesity class was not associated with risk, invasiveness, or timing of reoperations in a cohort of obese patients who underwent total hip arthroplasty [12].
  • Obese and overweight patients converted to total hip arthroplasty at significantly higher rates compared with normal-weight patients following hip arthroscopy for femoroacetabular impingement syndrome [13].
  • Current evidence does not support the routine use of tibial stem extensions in obese total knee arthroplasty patients due to insufficient, heterogeneous, and very low certainty data [14].
  • BMI was not associated with an increased risk of revision in primary anatomic total shoulder arthroplasty indicated for osteoarthritis, nor for primary reverse total shoulder arthroplasty indicated for rotator cuff arthropathy [22].
  • Patients with obesity had >2-fold odds of conversion to total hip arthroplasty compared with normal-weight patients following hip arthroscopy for femoroacetabular impingement syndrome [26].
  • The surgeon's obesity-specific annual primary total hip arthroplasty volume was not associated with the risk of revision or periprosthetic joint infection in patients who had a BMI ≥ 40 [27].
  • The complication profile was similar across the spectrum of BMI values following aseptic revision total knee arthroplasty, aside from rising BMI increasing early complications [29].
  • The ten-year functional outcomes and revision rates of total hip arthroplasty do not justify restricting access to surgery on the basis of BMI [40].

How It Works

Systemic and Metabolic Mechanisms

  • Obesity is a systemic disease with profound inflammatory consequences on joint health [8].
  • High BMI elevates the risk of both knee and hand osteoarthritis irrespective of metabolic status [33].
  • The increased risk of knee osteoarthritis attributed to high BMI is more evident in metabolically healthy participants [33].
  • Central obesity is significantly associated with the risk of glenohumeral joint osteoarthritis, especially in secondary GJO and normal BMI populations [35].
  • Each 1-unit increase in BMI was associated with a 9% reduction in osteoporosis risk [2].

Biomechanical and Structural Factors

  • Following medial meniscus posterior root tear repair, repairs show progression of osteoarthritis with higher rates seen with elevated BMI [31].
  • Obesity is modifiable, and addressing the issue can improve the orthopaedic and overall health of children [1].
  • There is enormous confusion about the relation of energy intake and energy expenditure to obesity, with much more attention focused on diet and obesity than on physical inactivity and obesity [4].

Impact on Surgical Outcomes

  • Modern surgical practices and implant designs may have mitigated traditional obesity-related risks regarding loosening and mechanical failure in total knee arthroplasty [15].
  • Obesity remains a critical risk factor for mechanical failures in functionally aligned image-based robotic total knee arthroplasty [18].
  • In a cohort of obese patients who underwent total hip arthroplasty, the WHO obesity class was not associated with risk, invasiveness, or timing of reoperations [12].
  • Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia for total knee arthroplasty [9].
  • Obese patients are at increased risk of a higher rate of revision following unicompartmental knee arthroplasty [21].
  • Obese and overweight patients converted to total hip arthroplasty at significantly higher rates compared with normal-weight patients after hip arthroscopy for femoroacetabular impingement syndrome [13].
  • No significant differences were observed between above-average and below-average BMI groups, and BMI was not correlated with clinical improvements following arthroscopically assisted posterior latissimus dorsi tendon transfer [7].
  • A nonsignificant trend toward a higher complication rate was observed in patients with severe obesity (BMI ≥35 kg/m2) undergoing robotic-assisted total knee arthroplasty [23].
  • A statistically significant increase in arthrofibrosis was found in patients with BMI <25 kg/m2 undergoing robotic-assisted total knee arthroplasty [23].
  • Obesity had a negative influence on lower extremity long bone fracture in-hospital outcomes in pediatric patients [17].
  • Type 2 diabetes is not an independent risk factor for reoperation when adjusted for BMI in obese patients undergoing total hip arthroplasty [20].

Risk Assessment and Patient Selection

  • The soft tissue-to-bone ratio reflects local anatomical factors that directly influence surgical exposure and wound healing, unlike BMI [30].
  • Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients who have normal BMIs at ambulatory surgical centers for primary total joint arthroplasty [3].
  • The numbers were too small to draw conclusions in patients who have a BMI ≥ 45 undergoing cementless total knee arthroplasty [5].
  • Very few patients who have obesity received preoperative weight loss management before total knee or hip arthroplasty via medications, nutrition services, or bariatric surgery regardless of sex or socioeconomic status [11].

Non-Operative Management and Lifestyle

  • Cardiorespiratory fitness is a strong predictor of cardiovascular disease and all-cause mortality and attenuates risks associated with overweight and obesity [34].
  • An aggregate exercise programme energy expenditure (>10 000 kcal) may be required to promote reductions in intrahepatic fat [19].
  • When combined with liraglutide treatment, exercise results in a more holistic state of health that may result in improved longer-term health and may enhance adherence to the treatment and promote longer-term weight-loss maintenance [16].
  • Findings support a BMI-based approach to perioperative semaglutide use, particularly in patients who have a BMI >30 [32].

What the Evidence Shows

General Pathophysiology and Systemic Effects

  • Obesity is a systemic disease with profound inflammatory consequences on joint health, extending beyond mechanical burden on the knee [8].
  • There is significant confusion regarding the relationship between energy intake, energy expenditure, and obesity, with greater attention historically focused on diet than on physical inactivity [4].

Bone Health and Metabolic Associations

  • An aggregate exercise programme energy expenditure greater than 10,000 kcal may be required to promote reductions in intrahepatic fat in adults who are overweight or have fatty liver disease [19].

Total Knee Arthroplasty (TKA)

  • BMI > 40 is not correlated with early complications in patients undergoing primary total joint arthroplasty at an ambulatory surgical center [3].
  • Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients with normal BMIs at ambulatory surgical centers [3].
  • BMI of 45 is identified as a safe cut-off for cementless total knee arthroplasty, though sample sizes were too small to draw conclusions for patients with a BMI ≥ 45 [5].
  • Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia [9].
  • Concern for stiffness alone should not serve as a categorical barrier to TKA or manipulation under anesthesia when clinically indicated [9].
  • Obesity remains a critical risk factor for mechanical failures in functionally aligned image-based robotic total knee arthroplasty, despite comparable functional outcomes [18].
  • A nonsignificant trend toward a higher complication rate was observed in patients with severe obesity (BMI ≥ 35 kg/m²) undergoing robotic-assisted total knee arthroplasty [23].
  • A statistically significant increase in arthrofibrosis was found in patients with BMI < 25 kg/m² undergoing robotic-assisted total knee arthroplasty [23].
  • Total weight loss percentage was higher in bariatric surgery patients (28.7%) compared to those undergoing immediate total knee arthroplasty for severe obesity and advanced knee osteoarthritis [37].

Total Hip Arthroplasty (THA)

  • The WHO obesity class was not associated with the risk, invasiveness, or timing of reoperations after total hip arthroplasty in a cohort of obese patients [12].
  • Semaglutide appears to be a safe alternative to bariatric surgery for weight management before total hip arthroplasty, with similar implant survival and postoperative complication rates [25].
  • Dual mobility implants demonstrated excellent five-year survivorship with outcomes comparable or slightly superior to fixed-bearing constructs in morbidly obese patients undergoing primary total hip arthroplasty [36].

Arthroscopy and Joint Preservation

  • Patients with obesity had greater than 2-fold odds of conversion to total hip arthroplasty compared with normal-weight patients following hip arthroscopy for femoroacetabular impingement syndrome [26].
  • Obesity and preexisting osteoarthritis are known risk factors for predicting poor outcomes and conversion to arthroplasty after knee arthroscopy [24].
  • Lower body mass index correlates with improved patient-reported symptoms at the time of surgery in modern hip arthroscopy patients [39].

Shoulder Arthroplasty and Rotator Cuff

  • BMI was not associated with an increased risk of revision in primary anatomic total shoulder arthroplasty indicated for osteoarthritis or primary reverse total shoulder arthroplasty indicated for rotator cuff arthropathy [22].
  • Overweight and premorbid obesity status correlates with thromboembolism risk but not infection after total shoulder arthroplasty [28].
  • BMI was not correlated with clinical improvements following arthroscopically assisted posterior latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears [7].

Pediatric and Trauma Outcomes

Weight Management and Exercise Interventions

  • Physical activity equivalent to approximately 30–35 minutes of vigorous intensity per week appears to offset the association between abdominal obesity and incident cardiovascular disease [6].
  • When combined with liraglutide treatment, exercise results in a more holistic state of health that may result in improved longer-term health and enhance adherence to treatment [16].
  • Women with high-intensity interval training had significant reduction in weight and BMI compared to those who followed a moderate-intensity continuous training protocol after bariatric surgery [38].

Practical Considerations

Preoperative Management and Patient Selection

  • Very few patients with obesity receive preoperative weight loss management via medications, nutrition services, or bariatric surgery before total knee or hip arthroplasty [11].
  • Semaglutide is a safe alternative to bariatric surgery for weight management before total hip arthroplasty, with similar implant survival and postoperative complication rates [25].
  • BMI ≥ 40 is not correlated with early complications in patients undergoing primary total joint arthroplasty at an ambulatory surgical center when preoperative comorbidities are managed and surgical planning is customized [3].
  • The surgeon's obesity-specific annual primary total hip arthroplasty volume is not associated with the risk of revision or periprosthetic joint infection in patients with a BMI ≥ 40 [27].

Operative Outcomes and Complications

  • Obesity class is not associated with the risk, invasiveness, or timing of reoperations after total hip arthroplasty [12].
  • BMI is not associated with an increased risk of revision in primary anatomic total shoulder arthroplasty for osteoarthritis or primary reverse total shoulder arthroplasty for rotator cuff arthropathy [22].
  • BMI does not affect clinical outcomes following arthroscopically assisted posterior latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears [7].
  • Obese and overweight patients convert to total hip arthroplasty at significantly higher rates compared with normal-weight patients after hip arthroscopy for femoroacetabular impingement syndrome [13].
  • Obesity is associated with higher rates of revision following unicompartmental knee arthroplasty [21].
  • Rising body mass index increases early complications but not early reoperations following aseptic revision total knee arthroplasty [29].
  • The complication profile is similar across the spectrum of BMI values in aseptic revision total knee arthroplasty, excluding the specific increase in early complications noted with rising BMI [29].
  • Total shoulder arthroplasty remains relatively safe in patients with elevated BMI [28].
  • Specific tibial stem extension designs may benefit selected populations of obese total knee arthroplasty patients [14].
  • Pediatric obesity has a negative influence on in-hospital outcomes for lower extremity long bone fractures [17].

Systemic and Metabolic Considerations

  • Obesity is a systemic disease with profound inflammatory consequences on joint health beyond mechanical burden [8].
  • When combined with liraglutide treatment, exercise results in a more holistic state of health that may improve longer-term health, enhance treatment adherence, and promote longer-term weight-loss maintenance [16].

Key Evidence

  • [L5] Obesity is modifiable, and addressing the issue can improve the orthopaedic and overall health of children. [1] (10.5435/jaaosglobal-d-19-00036)
  • [L1] Based on our dose–response analysis of nine studies, each 1-unit increase in BMI was associated with a 9% reduction in osteoporosis risk. [2] (10.1186/s12891-026-09675-3)
  • [L3] Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients who have normal BMIs at ASCs, questioning BMI as an exclusion criterion and advocating for more inclusive, evidence-based patient selection. [3] (10.1016/j.arth.2025.08.065)
  • [L5] There is enormous confusion about the relation of energy intake and energy expenditure to obesity, with much more attention focused on diet and obesity than on physical inactivity and obesity. [4] (10.1136/bjsports-2015-094911)
  • [L3] However, the numbers were too small to draw conclusions in patients who have a BMI ≥ 45. [5] (10.1016/j.arth.2025.12.038)
  • [L3] Physical activity equivalent to approximately 30–35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident CVD. [6] (10.1136/bjsports-2023-107252)
  • [L2] No significant differences were observed between above-average and below-average BMI groups, and BMI was not correlated with clinical improvements. [7] (10.1016/j.xrrt.2025.100634)
  • [L5] Obesity is more than a mechanical burden on the knee; it is a systemic disease with profound inflammatory consequences on joint health. [8] (10.1002/arj.70051)
  • [L3] These findings suggest that increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following MUA and that concern for stiffness alone should not serve as a categorical barrier to TKA or MUA when clinically indicated. [9] (10.1016/j.arth.2026.03.080)
  • [L3] BMI has a weak-to-moderate association with peri-incisional adiposity in primary total joint arthroplasty patients. [10] (10.1016/j.arth.2024.08.020)
  • [L3] Very few patients who have obesity received preoperative weight loss management before TKA or THA via medications, nutrition services, or bariatric surgery regardless of sex or socioeconomic status. [11] (10.1016/j.arth.2026.06.021)
  • [L3] In this cohort of obese patients who underwent THA, the WHO obesity class was not associated with risk, invasiveness, or timing of reoperations. [12] (10.1016/j.arth.2025.07.026)
  • [L3] Obese and overweight patients converted to THA at significantly higher rates compared with normal-weight patients. [13] (10.1177/03635465251400355)
  • [L5] The authors conclude that current evidence does not support the routine use of tibial stem extensions in obese total knee arthroplasty patients due to insufficient, heterogeneous, and very low certainty data, though specific designs may benefit selected populations. [14] (10.1016/j.arth.2025.11.056)
  • [L3] These findings suggest modern surgical practices and implant designs may have mitigated traditional obesity-related risks. [15] (10.1016/j.arth.2026.04.031)
  • [Paper] It is clear that, when combined with liraglutide treatment, exercise results in a more holistic state of health that may result in improved longer-term health and may enhance adherence to the treatment and promote longer-term weight-loss maintenance. [16] (10.1136/bjsports-2021-104754)
  • [L4] Overall, these findings suggested that obesity had a negative influence on lower extremity long bone fracture in-hospital outcomes. [17] (10.1186/s12891-025-09349-6)
  • [L3] However, obesity remains a critical risk factor for mechanical failures. [18] (10.1016/j.jisako.2025.100861)
  • [L1] An aggregate exercise programme energy expenditure (>10 000 kcal) may be required to promote reductions in intrahepatic fat. [19] (10.1136/bjsports-2016-096197)
  • [L2] Overall, T2DM is not an independent risk factor for reoperation when adjusted for BMI. [20] (10.1186/s12891-026-09568-5)
  • [L3] Based on AOANJRR data, obese patients are at increased risk of higher rate of revision following UKA. [21] (10.1177/2325967125s00336)
  • [L3] BMI was not associated with an increased risk of revision in primary aTSA indicated for osteoarthritis, nor for primary rTSA indicated for rotator cuff arthropathy. [22] (10.1016/j.jse.2025.05.036)
  • [L2] However, a nonsignificant trend toward a higher complication rate was observed in patients with severe obesity (BMI ≥35 kg/m2), while a statistically significant increase in arthrofibrosis was found in patients with BMI <25 kg/m2. [23] (10.1016/j.jisako.2025.100927)
  • [L5] Obesity and preexisting osteoarthritis are known risk factors for predicting poor outcomes and conversion to arthroplasty after knee arthroscopy, but the study lacks a control group and specific procedural details to determine if the surgery itself drives progression versus patient factors. [24] (10.1016/j.arthro.2025.04.036)
  • [L3] Semaglutide appears to be a safe alternative to bariatric surgery for weight management before THA, with similar implant survival and postoperative complication rates. [25] (10.1016/j.arth.2025.08.068)
  • [L3] However, patients with obesity had >2-fold odds of conversion to THA. [26] (10.1177/03635465251392585)
  • [L3] However, the surgeon's obesity-specific annual primary THA volume was not associated with the risk of revision or PJI in patients who had a BMI ≥ 40. [27] (10.1016/j.arth.2025.07.037)
  • [L3] These findings support individualized thromboembolic risk assessment while suggesting TSA remains relatively safe in patients with elevated BMI. [28] (10.1016/j.jse.2026.05.022)
  • [L3] Otherwise, the complication profile was similar across the spectrum of BMI values. [29] (10.1016/j.arth.2026.01.024)
  • [L3] Unlike BMI, the STiB ratio reflects local anatomical factors that directly influence surgical exposure and wound healing. [30] (10.1016/j.arth.2025.09.022)
  • [L1] Following MMPRT repair, repairs show progression of osteoarthritis with higher rates seen with elevated BMI. [31] (10.1002/arj.70028)
  • [L3] Our findings support a BMI-based approach to perioperative semaglutide use, particularly in patients who have a BMI >30. [32] (10.1016/j.arth.2025.09.056)
  • [L2] High BMI elevates the risk of both knee and hand osteoarthritis irrespective of metabolic status, and the increased risk of knee osteoarthritis attributed to high BMI is more evident in metabolically healthy participants. [33] (10.1186/s12891-026-09495-5)
  • [L1] CRF is a strong predictor of CVD and all-cause mortality and attenuates risks associated with overweight and obesity. [34] (10.1136/bjsports-2024-108748)
  • [L2] Central obesity is significantly associated with the risk of glenohumeral joint osteoarthritis, especially in secondary GJO and normal BMI populations, suggesting that fat distribution should be included in the early screening and risk assessment system for GJO. [35] (10.1016/j.jse.2025.07.007)
  • [L3] In morbidly obese patients, DM implants demonstrated excellent five-year survivorship with outcomes comparable or slightly superior to fixed-bearing constructs. [36] (10.1016/j.arth.2026.03.075)
  • [L1] Total weight loss % was higher in bariatric surgery patients (28.7%, P < 0.001). [37] (10.1016/j.arth.2026.05.033)
  • [L1] Additionally, women with HIIT training had significant reduction in their weight and BMI compared to those who followed MICT training protocol. [38] (10.1186/s12891-026-09722-z)
  • [L4] This multicenter data set has demonstrated improved patient-reported symptoms at the time of surgery, a decrease in mean patient BMI, and an increase in symptom duration reported prior to surgery. [39] (10.1002/ksa.12745)
  • [L3] The ten-year functional outcomes and revision rates of THA do not justify restricting access to surgery on the basis of BMI. [40] (10.1016/j.arth.2025.07.044)

References

[1] The Role of Obesity in Pediatric Orthopedics. JAAOS: Global Research and Reviews. 2019. DOI: 10.5435/jaaosglobal-d-19-00036

[2] The association between body mass index and osteoporosis, with consideration of sex differences: a systematic review and dose-response meta-analysis. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09675-3

[3] Body Mass Index > 40 Is Not Correlated With Early Complications in Patients Undergoing Primary Total Joint Arthroplasty at an Ambulatory Surgical Center. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.08.065

[4] It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet. British Journal of Sports Medicine. 2015. DOI: 10.1136/bjsports-2015-094911

[5] Body Mass Index of 45 Is a Safe Cut-Off for Cementless Total Knee Arthroplasty. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2025.12.038

[6] Joint associations of device-measured physical activity and abdominal obesity with incident cardiovascular disease: a prospective cohort study. British Journal of Sports Medicine. 2023. DOI: 10.1136/bjsports-2023-107252

[7] Body mass index does not affect clinical outcomes following arthroscopically assisted posterior latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears: a minimum 5-year follow-up study. JSES Reviews, Reports, and Techniques. 2026. DOI: 10.1016/j.xrrt.2025.100634

[8] Reframing Obesity in Knee Osteoarthritis: A Call for a Transdisciplinary Approach Beyond Biomechanics. Arthroscopy. 2026. DOI: 10.1002/arj.70051

[9] Obesity Severity and Stiffness After Total Knee Arthroplasty Revisited: A Contemporary Analysis of Patients Requiring Manipulation Under Anesthesia. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.03.080

[10] Body Mass Index is Not an Appropriate Proxy for the Condition of Peri-Incisional Adiposity in Primary Total Joint Arthroplasty Patients. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2024.08.020

[11] Disparities in Preoperative Weight Loss and Obesity Treatment Before Total Joint Arthroplasty. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.06.021

[12] Obesity Class Does Not Associate With Incidence, Timing, or Invasiveness of Reoperations After Total Hip Arthroplasty. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.07.026

[13] The Effect of Body Mass Index on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Matched Analysis With 10-Year Follow-up. The American Journal of Sports Medicine. 2026. DOI: 10.1177/03635465251400355

[14] Reply to: "Letter to the Editor Commenting on: 'Current Evidence Does Not Support the Use of Tibial Stem Extension in Total Knee Arthroplasty of Obese Patients: A Systematic Review'". The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.11.056

[15] Obesity and Total Knee Arthroplasty Revisited: Minimal Impact on Loosening and Mechanical Failure in the Modern Era. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.04.031

[16] Exercise in the maintenance of weight loss: health benefits beyond lost weight on the scale. British Journal of Sports Medicine. 2021. DOI: 10.1136/bjsports-2021-104754

[17] Impact of pediatric obesity on surgical outcomes of lower extremity fractures: a nationwide analysis (2010–2019). BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-025-09349-6

[18] Impact of high body mass index on functionally aligned image-based robotic total knee arthroplasty: Comparable functional outcomes but higher mechanical failures. Journal of ISAKOS. 2025. DOI: 10.1016/j.jisako.2025.100861

[19] Effect of exercise training on liver function in adults who are overweight or exhibit fatty liver disease: a systematic review and meta-analysis. British Journal of Sports Medicine. 2016. DOI: 10.1136/bjsports-2016-096197

[20] Type 2 diabetes is not associated with excess risk of periprosthetic joint infection in obese patients undergoing total hip arthroplasty. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09568-5

[21] Obesity is Associated with Higher Rates of Revision Following Unicompartmental Knee Arthroplasty. Orthopaedic Journal of Sports Medicine. 2026. DOI: 10.1177/2325967125s00336

[22] Revision rates between obese and nonobese total shoulder arthroplasty patients: an Australian registry data study. Journal of Shoulder and Elbow Surgery. 2026. DOI: 10.1016/j.jse.2025.05.036

[23] Impact of body mass index on robotic-assisted total knee arthroplasty outcomes: A retrospective cohort analysis. Journal of ISAKOS. 2025. DOI: 10.1016/j.jisako.2025.100927

[24] Editorial Commentary: Obesity and Osteoarthritis Are Risk Factors for Conversion to Arthroplasty, With or Without Previous Knee Arthroscopic Surgery. Arthroscopy. 2025. DOI: 10.1016/j.arthro.2025.04.036

[25] Is Semaglutide a Safer Weight-Management Option Than Bariatric Surgery for Patients Undergoing Total Hip Arthroplasty (THA)?. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.08.068

[26] Obese Patients Treated by Hip Arthroscopy for Femoroacetabular Impingement Syndrome — 10-Year Functional Outcomes and Conversion Rates to Arthroplasty Compared With Normal-Weight Patients. The American Journal of Sports Medicine. 2026. DOI: 10.1177/03635465251392585

[27] Effects of Surgeon Volume on Outcomes Following Primary Total Hip Arthroplasty in the Morbidly Obese: An Analysis From the American Joint Replacement Registry. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.07.037

[28] Overweight and Premorbid Obesity Status Correlates With Thromboembolism Risk but Not Infection After Total Shoulder Arthroplasty. Journal of Shoulder and Elbow Surgery. 2026. DOI: 10.1016/j.jse.2026.05.022

[29] Rising Body Mass Index Increased Early Complications, But Not Early Reoperations Following Aseptic Revision Total Knee Arthroplasty. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.01.024

[30] Soft Tissue-To-Bone Ratio Outperforms Body Mass Index in Predicting Periprosthetic Joint Infection in Total Knee Arthroplasty: A Retrospective Case-Control Study. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.09.022

[31] Medial Meniscus Posterior Root Tear Repairs Show Osteoarthritis Progression Over Time With Higher Rates Seen With Higher Body Mass Index. Arthroscopy. 2026. DOI: 10.1002/arj.70028

[32] The Effect of Body Mass Index on the Efficacy of Semaglutide Use at the Time of Total Knee Arthroplasty. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.09.056

[33] Does metabolically healthy obesity increase the risk of knee and hand osteoarthritis? A population-based cohort study. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09495-5

[34] Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis. British Journal of Sports Medicine. 2024. DOI: 10.1136/bjsports-2024-108748

[35] Association between central obesity and the risk of glenohumeral joint osteoarthritis: a prospective study. Journal of Shoulder and Elbow Surgery. 2026. DOI: 10.1016/j.jse.2025.07.007

[36] Primary Total Hip Arthroplasty in Patients Who Have Morbid Obesity: A Propensity-Weighted Analysis of Dual Mobility and Standard Fixed-Bearing Implants. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.03.075

[37] Impact Of Prior Bariatric Surgery Versus Immediate Total Knee Arthroplasty On Knee Function Among Patients Who Have Severe Obesity And Advanced Knee Osteoarthritis: The SWIFT Trial. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2026.05.033

[38] Impact of high-intensity interval training vs. moderate-intensity continuous training combined with strength training on physical and metabolic outcomes in post-bariatric surgery patients with sarcopenic obesity. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09722-z

[39] Lower body mass index and symptom burden in modern hip arthroscopy patients: Updated epidemiology and trends from the MASH multicenter cohort. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12745

[40] Do the Ten-Year Functional Outcomes and Revision Rates of Total Hip Arthroplasty in Obese and Morbidly Obese Patients Justify Restricting Their Access to Surgery?. The Journal of Arthroplasty. 2026. DOI: 10.1016/j.arth.2025.07.044