Patients › General-Health
Peso, obesidade e saúde das articulações
How body weight and obesity affect joint load, osteoarthritis, and the risks and outcomes of joint surgery — including the role of weight loss before an operation.
O que é¶
O peso e a saúde das articulações estão intimamente ligados. Carregar peso extra coloca mais carga sobre as suas articulações, principalmente sobre a parte interna do joelho. Isso ajuda a explicar por que a artrose por desgaste (osteoartrite) é comum na parte interna do joelho em pessoas que vivem com obesidade [1]. O peso extra também afeta todo o seu corpo, e não apenas as articulações. A obesidade é uma doença que causa inflamação em todo o corpo, e essa inflamação também chega às suas articulações [2].
Esta página é para qualquer pessoa que carrega peso extra e tem dor nas articulações, ou que está pensando em fazer uma cirurgia articular. Ela também é para os pais, porque a obesidade em crianças é uma condição que pode mudar, e tratá-la pode melhorar a saúde das articulações e a saúde geral delas [3]. A boa notícia é que o peso é uma das coisas sobre as quais você pode fazer algo. Perder peso pode aliviar os sintomas nas articulações e diminuir alguns riscos relacionados à cirurgia.
O peso extra afeta as articulações de duas formas principais. A primeira é mecânica: mais carga passa pela articulação a cada passo. A segunda é química: a inflamação que acompanha a obesidade pode desgastar a superfície lisa dentro da articulação, e essa superfície pode não se adaptar bem a cargas maiores em adultos com obesidade [4]. No outro extremo da balança, estar abaixo do peso também traz riscos, incluindo alguns que se sobrepõem aos observados na obesidade [5].
O peso e a cirurgia estão ligados nos dois sentidos. Pessoas com sobrepeso ou obesidade tendem a precisar de prótese de quadril e de joelho mais jovens do que pessoas com peso normal [6]. Mas o peso extra não exclui a cirurgia. Pesquisas que avaliaram os resultados de dez anos após a prótese de quadril não encontraram motivo para restringir o acesso à cirurgia com base apenas no IMC [7]. Cuidar das outras condições de saúde e planejar a sua operação com cuidado pode levar a resultados semelhantes aos de pacientes com IMC normal [8].
Funciona mesmo?¶
A resposta honesta é que as evidências são mistas, e algumas delas são escassas. Perder peso pode aliviar os sintomas nas articulações e diminuir alguns riscos relacionados à cirurgia. Essa mensagem geral se sustenta. Mas, quando os pesquisadores examinam de perto operações específicas, o quadro é menos claro.
Nas próteses de quadril e de joelho, o peso extra aumenta a chance de precisar de uma operação de correção em alguns procedimentos. Estudos encontraram taxas mais altas de revisão após a prótese parcial de joelho em pessoas com obesidade [9], e taxas mais altas de revisão após a prótese reversa de ombro feita por fraturas [10]. Na prótese de quadril, um estudo verificou que a classe de obesidade não estava associada ao risco, ao grau de invasividade nem ao momento de novas operações [11]. Resultados como esses não apontam todos na mesma direção, e grande parte das pesquisas é pequena ou de curto prazo.
Alguns resultados são tranquilizadores, em termos simples. Após a cirurgia do quadril por vídeo, as pessoas com obesidade tiveram melhoras a longo prazo na dor e na função iguais às das pessoas com peso normal [12]. Após a cirurgia de fratura do punho, um estudo não encontrou diferença no movimento da articulação entre pessoas com peso normal e pessoas com obesidade [13]. Por outro lado, a cirurgia do joelho por vídeo tende a funcionar menos bem em pessoas com obesidade, principalmente quando já existe artrose [14].
Também há lacunas. Em pessoas com IMC de 45 ou mais, os estudos sobre um tipo de prótese de joelho foram pequenos demais para tirar conclusões firmes [15]. Para algumas escolhas cirúrgicas, os dados disponíveis são fracos demais para sustentar uma orientação firme em um sentido ou no outro [16].
A mensagem para você é esta. O peso extra muda alguns riscos relacionados à cirurgia articular, mas não exclui a cirurgia, e muitas pessoas com obesidade se saem bem após a operação. O seu médico pode conversar com você sobre quais desses resultados se aplicam à sua articulação e à sua situação.
Quais são os riscos?¶
Os riscos mais prováveis relacionados à cirurgia articular são os que você nota nos primeiros dias e semanas: problemas na ferida, rigidez e uma recuperação mais lenta. O peso extra pode tornar alguns deles mais prováveis. Após a cirurgia de fraturas do braço e da mão, as pessoas com obesidade tiveram taxas de complicações mais altas nos primeiros 90 dias e novamente aos 2 anos [17]. Aos 2 anos, essas complicações incluíram a consolidação do osso na posição errada, a falta de consolidação do osso e a necessidade de nova cirurgia [17].
Alguns riscos dependem da articulação e da operação. Após a prótese parcial de joelho, as pessoas com obesidade precisaram de operações de correção com mais frequência [9]. O mesmo aconteceu após a prótese reversa de ombro feita por fraturas, em que o peso extra esteve associado a mais correções no geral e a mais problemas com a articulação saindo do lugar [10]. Em um tipo de prótese de joelho robótica, a obesidade continuou sendo um fator de risco para o implante se soltar com o desgaste ou falhar mecanicamente [18].
Nem todos os riscos apontam na mesma direção, e alguns resultados são realmente mistos. Em outro estudo sobre prótese de joelho robótica, a tendência a mais complicações em pessoas com obesidade grave (IMC de 35 ou mais) não foi estatisticamente clara [19]. A rigidez após a prótese de joelho é uma preocupação conhecida, mas um estudo verificou que um peso maior não estava associado a mais rigidez nem a resultados piores após um procedimento para soltar um joelho rígido [20]. Estar abaixo do peso também traz riscos, e alguns deles se sobrepõem aos riscos da obesidade [5].
Também há lacunas reais no que se sabe. Em pessoas com IMC de 45 ou mais, os estudos sobre um tipo de prótese de joelho foram pequenos demais para tirar conclusões firmes sobre a segurança [15]. Em crianças com fraturas dos membros inferiores, a obesidade significou internações mais longas no hospital e mais altas hospitalares que as famílias não desejavam [21].
O quadro geral é este. O peso extra aumenta alguns riscos relacionados à cirurgia, mas não exclui a cirurgia, e muitos desses riscos podem ser reduzidos cuidando das outras condições de saúde e planejando a sua operação com cuidado [8]. O seu médico pode conversar com você sobre quais deles se aplicam a você.
É a opção certa para você?¶
Se você carrega peso extra e tem dor nas articulações, esta página foi escrita para você. O peso extra não exclui a cirurgia. Muitas pessoas com obesidade se saem bem após a prótese de quadril e de joelho, principalmente quando as outras condições de saúde são controladas e a operação é planejada com cuidado [8]. Perder peso antes da cirurgia pode aliviar os sintomas nas articulações e diminuir alguns riscos relacionados à operação.
A cirurgia não é o único caminho. Em algumas articulações e algumas operações, o peso extra aumenta a chance de precisar de uma operação de correção mais tarde [9]. O seu médico pode comparar as opções com você, incluindo cuidados não cirúrgicos, como exercícios e controle do peso, e ajudar você a avaliar o que cada uma oferece.
Esta é uma decisão compartilhada. Você traz os seus objetivos, a sua dor e o seu dia a dia. O seu médico traz as evidências sobre a sua articulação e a sua situação. Juntos, vocês podem decidir o momento e o tipo de tratamento mais adequados para você.
Conclusão¶
Carregar peso extra afeta as suas articulações e alguns dos riscos relacionados à cirurgia, mas não exclui a cirurgia. Perder peso pode aliviar os sintomas nas articulações e diminuir alguns desses riscos, e vale a pena considerá-lo como parte do seu plano, junto com exercícios e outros cuidados. A expectativa realista é de um progresso constante, e não de uma solução rápida, porque os resultados variam de pessoa para pessoa. A ressalva mais importante é que as evidências sobre operações específicas são mistas; por isso, converse com o seu médico sobre quais resultados se aplicam à sua articulação e à sua situação.
Referências¶
[1] Cartilage contact characteristics of the knee during gait in individuals with obesity. Journal of Orthopaedic Research. 2022. DOI: 10.1002/jor.25288
[2] Reframing Obesity in Knee Osteoarthritis: A Call for a Transdisciplinary Approach Beyond Biomechanics. Arthroscopy. 2026. DOI: 10.1002/arj.70051
[3] The Role of Obesity in Pediatric Orthopedics. JAAOS: Global Research and Reviews. 2019. DOI: 10.5435/jaaosglobal-d-19-00036
[4] Body mass index moderates the association between gait kinetics, body composition, and femoral knee cartilage characteristics. Journal of Orthopaedic Research. 2020. DOI: 10.1002/jor.24655
[5] Weight on the fixation: the influence of body mass index on lower extremity fracture fixation outcomes. Injury. 2025. DOI: 10.1016/j.injury.2025.112864
[6] Overweight and Obese Patients Require Total Hip and Total Knee Arthroplasty at a Younger Age. Journal of Orthopaedic Research. 2019. DOI: 10.1002/jor.24460
[7] 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
[8] 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
[9] Obesity is Associated with Higher Rates of Revision Following Unicompartmental Knee Arthroplasty. Orthopaedic Journal of Sports Medicine. 2026. DOI: 10.1177/2325967125s00336
[10] 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
[11] 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
[12] 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
[13] Influence of body mass index on health-related quality of life after surgical treatment of intra-articular distal radius fractures. A retrospective 7-year follow-up study. Hand Surgery and Rehabilitation. 2019. DOI: 10.1016/j.hansur.2019.09.004
[14] 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
[15] 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
[16] 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
[17] Obesity is associated with higher 90-day and 2-year complication rates following surgical fixation of upper extremity fractures: A nationwide analysis. Injury. 2025. DOI: 10.1016/j.injury.2025.112891
[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] 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
[20] 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
[21] 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
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].
- Obesity is a systemic disease with profound inflammatory consequences on joint health, extending beyond mechanical burden [11].
- There is significant confusion regarding the relationship between energy intake, energy expenditure, and obesity, with greater attention historically focused on diet than physical inactivity [5].
- 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 [10].
- Each 1-unit increase in body mass index is associated with a 9% reduction in osteoporosis risk [2].
- Obesity affects knee cartilage contact location primarily in the medial compartment, which explains part of the high prevalence of medial knee osteoarthritis in the obese population [17].
- Increased CDC weight category is associated with worsening clinical outcomes across all measures following meniscus repair in pediatric and adolescent populations [8].
- Increased body mass index among patients with total joint replacement is associated with decreased ambulatory activity [13].
- Overweight and obese patients require total hip and total knee arthroplasty at a significantly younger age than normal-weight patients [18].
- Obese and overweight patients convert to total hip arthroplasty at significantly higher rates compared with normal-weight patients following hip arthroscopy for femoroacetabular impingement syndrome [22].
- Underweight patients demonstrate an elevated risk for complications that overlap with those seen in obese patients following lower extremity fracture fixation, yet experience lower rates of other complications [6].
- In a cohort of obese patients undergoing total hip arthroplasty, WHO obesity class was not associated with the risk, invasiveness, or timing of reoperations [21].
- Ten-year functional outcomes and revision rates of total hip arthroplasty do not justify restricting access to surgery on the basis of body mass index [51].
- Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia after total knee arthroplasty [12].
- Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients with normal body mass index in ambulatory surgical centers, questioning body mass index as an exclusion criterion for primary total joint arthroplasty [3].
- 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 [15].
- The absence of direct comparative studies precludes causal inference regarding the role of weight-bearing timing in medial meniscus posterior root tear repair [7].
- Mortality did not decrease in association with increasing body mass index in isolated blunt abdominal trauma, as this may be offset by the increase in co-morbidities in this population [4].
- The Arthritis Committee recognizes the profound importance of arthritic disorders to the general population, not only as a health problem, but for their social and economic impact [25].
- Both the individual and the physician have many options from which to choose when selecting an appropriate weight loss program [14].
How It Works¶
Systemic and Metabolic Mechanisms¶
- Obesity is a systemic disease with profound inflammatory consequences on joint health [11].
- Obesity promotes lipid accumulation in mouse cartilage via acetyl-CoA carboxylase (ACC) mediated chondrocyte de novo lipogenesis [41].
- Inhibition of ACC ameliorates lipid accumulation in chondrocytes, suggesting ACC could be targeted to treat obesity-associated osteoarthritis [41].
- Diet-induced obesity alters bone morphology and mineral density in a manner dependent on dietary free fatty acid content [40].
- Adolescent murine obesity alters structural, mechanical, and compositional properties of bone, which may have lasting implications on bone health even after obesity is corrected [36].
- There is confusion regarding the relation of energy intake and energy expenditure to obesity, with more attention focused on diet than physical inactivity [5].
- An aggregate exercise programme energy expenditure greater than 10,000 kcal may be required to promote reductions in intrahepatic fat [20].
- When combined with liraglutide treatment, exercise results in a more holistic state of health that may enhance adherence and promote longer-term weight-loss maintenance [19].
Biomechanical and Cartilage Effects¶
- Obesity affects knee cartilage contact location mainly in the medial compartment, explaining part of the high prevalence of medial knee osteoarthritis in the obese population [17].
- Articular cartilage may not adapt to higher joint loads in adults with obesity [39].
- Aging and obesity are associated with a loss of the positive relationship between cartilage thickness and ambulatory loads [23].
- Under weight-bearing conditions, patellofemoral joint contact areas increased by an average of 24% [43].
- Obesity did not enhance cartilage degeneration in the absence of fracture or surgical trauma [34].
Clinical Outcomes and Complications¶
- Each 1-unit increase in BMI is associated with a 9% reduction in osteoporosis risk [2].
- Following medial meniscus posterior root tear repair, osteoarthritis progression occurs at higher rates with elevated BMI [38].
- Obese patients demonstrate increased risks of malunion, nonunion, and revision at 2 years following surgical fixation of upper extremity fractures [26].
- Underweight patients demonstrate an elevated risk for complications that overlap with those seen in obese patients following lower extremity fracture fixation [6].
- Obesity remains a critical risk factor for mechanical failures in functionally aligned image-based robotic total knee arthroplasty [28].
- 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 [42].
- A statistically significant increase in arthrofibrosis was found in patients with BMI <25 kg/m2 undergoing robotic-assisted total knee arthroplasty [42].
- Modern surgical practices and implant designs may have mitigated traditional obesity-related risks regarding loosening and mechanical failure in total knee arthroplasty [24].
- Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia for total knee arthroplasty [12].
- 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 for primary total joint arthroplasty [3].
- Body mass index has a weak-to-moderate association with peri-incisional adiposity in primary total joint arthroplasty patients [27].
- The soft tissue-to-bone ratio reflects local anatomical factors that directly influence surgical exposure and wound healing, unlike BMI [35].
- No significant differences were observed between above-average and below-average BMI groups regarding clinical improvements following arthroscopically assisted posterior latissimus dorsi tendon transfer [16].
Trauma and Mortality¶
- Mortality did not decrease in association with increasing BMI in isolated blunt abdominal trauma, potentially offset by increased co-morbidities [4].
- The "Obesity Paradox" in major trauma is explained by biomechanical protection resulting in a lower Injury Severity Score, which neutralizes the increased physiological and comorbidity burden of the obese state [37].
Modifiability and Management¶
- Obesity is modifiable, and addressing the issue can improve the orthopaedic and overall health of children [1].
- Both individuals and physicians have many options from which to choose when selecting an appropriate weight loss program [14].
What the Evidence Shows¶
Pediatric Orthopedics¶
- Increased CDC weight category is associated with worsening clinical outcomes across all measures in pediatric and adolescent populations following meniscus repair [8].
- Pediatric obesity substantially lengthened length of stay and encouraged undesirable discharge when compared to non-obese individuals in lower extremity fracture cases [32].
Bone Density and Systemic Effects¶
- Each 1-unit increase in BMI was associated with a 9% reduction in osteoporosis risk based on a dose–response analysis of nine studies [2].
- Obesity is more than a mechanical burden on the knee; it is a systemic disease with profound inflammatory consequences on joint health [11].
Total Joint Arthroplasty: Knee¶
- 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 knee arthroplasty, questioning BMI as an exclusion criterion [3].
- Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia, and concern for stiffness alone should not serve as a categorical barrier to total knee arthroplasty or manipulation under anesthesia when clinically indicated [12].
- Obesity remains a critical risk factor for mechanical failures in functionally aligned image-based robotic total knee arthroplasty, despite comparable functional outcomes [28].
- Obese patients are at increased risk of higher rate of revision following unicompartmental knee arthroplasty based on AOANJRR data [33].
- Total weight loss percentage was higher in bariatric surgery patients (28.7%, P < 0.001) compared to immediate total knee arthroplasty in patients with severe obesity and advanced knee osteoarthritis [47].
- The numbers were too small to draw conclusions in patients who have a BMI ≥ 45 regarding the safety of cementless total knee arthroplasty [9].
Total Joint Arthroplasty: Hip¶
- 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 [21].
- In morbidly obese patients, dual mobility implants demonstrated excellent five-year survivorship with outcomes comparable or slightly superior to fixed-bearing constructs [44].
- 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 [30].
Total Joint Arthroplasty: Shoulder¶
- Obesity has an increased risk of all-cause revisions and revision for instability or dislocation in patients receiving reverse total shoulder arthroplasty indicated for fractures [29].
Arthroscopy and Soft Tissue¶
- 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 [22].
- Hip arthroscopy for the treatment of femoroacetabular impingement and labral tears in patients with obesity yielded significant and sustainable long-term improvements, which were equivalent to those of a benchmark matched control group of normal-weight patients [45].
- 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 [16].
- 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 [50].
Fracture Fixation and Trauma¶
- Underweight patients demonstrated an elevated risk for complications that overlapped with those seen in obese patients, yet experienced lower rates of others, in lower extremity fracture fixation [6].
- At 2 years, obese patients demonstrated increased risks of malunion, nonunion, and revision following surgical fixation of upper extremity fractures [26].
- Mortality did not decrease in association with increasing BMI in isolated blunt abdominal trauma, as this may be offset by the increase in co-morbidities in this population [4].
Patient Selection and Preoperative Factors¶
- BMI has a weak-to-moderate association with peri-incisional adiposity in primary total joint arthroplasty patients [27].
- Women had decreased odds of losing greater than five pounds before surgery despite increased odds of having preoperative bariatric surgery [31].
- Increased body mass index among patients with a total joint replacement is associated with decreased ambulatory activity [13].
Weight Management and Lifestyle¶
- 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 [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 [10].
- 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 [19].
- An aggregate exercise programme energy expenditure (>10 000 kcal) may be required to promote reductions in intrahepatic fat in adults who are overweight or exhibit fatty liver disease [20].
- Women with high-intensity interval training had significant reduction in their weight and BMI compared to those who followed moderate-intensity continuous training protocol in post-bariatric surgery patients with sarcopenic obesity [48].
Practical Considerations¶
Preoperative Management and Weight Loss¶
- Obesity is a modifiable condition, and addressing it can improve orthopaedic and overall health in children [1].
- There is significant confusion regarding the relationship between energy intake, energy expenditure, and obesity, with greater attention focused on diet than on physical inactivity [5].
- Both individuals and physicians have multiple options available when selecting an appropriate weight loss program [14].
- 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 [19].
Arthroplasty Outcomes and Complications¶
- 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, questioning BMI as an exclusion criterion [3].
- The numbers in the study were too small to draw conclusions in patients who have a BMI ≥ 45 regarding cementless total knee arthroplasty [9].
- Increasing obesity severity is not associated with higher rates of postoperative stiffness or inferior outcomes following manipulation under anesthesia, and concern for stiffness alone should not serve as a categorical barrier to TKA or MUA when clinically indicated [12].
- Obesity is associated with higher rates of revision following unicompartmental knee arthroplasty based on AOANJRR data [33].
- Overweight and obese patients require total hip and total knee arthroplasty at a significantly younger age compared to normal-weight patients [18].
Fracture and Trauma Outcomes¶
- Underweight patients demonstrated an elevated risk for complications that overlapped with those seen in obese patients, yet experienced lower rates of other complications in lower extremity fracture fixation [6].
- Obesity substantially lengthened length of stay and encouraged undesirable discharge when compared to non-obese individuals in pediatric lower extremity fractures [32].
Joint Health and Biomechanics¶
- Obesity is a systemic disease with profound inflammatory consequences on joint health, extending beyond a mechanical burden on the knee [11].
- Obesity affects the contact location mainly in the medial compartment of the knee, which explains, in part, the high prevalence of medial knee osteoarthritis in the obese population [17].
- Aging and obesity are both associated with a loss of the positive relationship between cartilage thickness and ambulatory loads, and this relationship is dependent on the compartment and whether the load is generated by body size or subject-specific gait mechanics [23].
Soft Tissue and Arthroscopic Outcomes¶
- The absence of direct comparative studies precludes causal inference regarding the role of weight-bearing timing in medial meniscus posterior root tears repair [7].
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)
- [L3] Mortality did not decrease in association with increasing BMI, as this may be offset by the increase in co-morbidities in this population. [4] (10.1016/j.injury.2024.111612)
- [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. [5] (10.1136/bjsports-2015-094911)
- [L3] Underweight patients demonstrated an elevated risk for complications that overlapped with those seen in obese patients, yet experienced lower rates of others. [6] (10.1016/j.injury.2025.112864)
- [L4] However, the absence of direct comparative studies precludes causal inference regarding the role of weight-bearing timing. [7] (10.1002/arj.70529)
- [L3] Increased CDC weight category is associated with worsening clinical outcomes across all measures. [8] (10.1016/j.injury.2026.113122)
- [L3] However, the numbers were too small to draw conclusions in patients who have a BMI ≥ 45. [9] (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. [10] (10.1136/bjsports-2023-107252)
- [L5] Obesity is more than a mechanical burden on the knee; it is a systemic disease with profound inflammatory consequences on joint health. [11] (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. [12] (10.1016/j.arth.2026.03.080)
- [L4] We therefore conclude that increased body mass index (greater obesity) among patients with a total joint replacement is associated with decreased ambulatory activity. [13] (10.1002/jor.1100180106)
- [Paper] Both the individual and the physician have many options from which to choose when selecting an appropriate weight loss program. [14] (10.1016/s0278-5919(05)70176-9)
- [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. [15] (10.1016/j.arth.2025.11.056)
- [L2] No significant differences were observed between above-average and below-average BMI groups, and BMI was not correlated with clinical improvements. [16] (10.1016/j.xrrt.2025.100634)
- [L4] These findings suggest that obesity affects the contact location mainly in the medial compartment, which explains, in part, the high prevalence of medial knee OA in the obese population. [17] (10.1002/jor.25288)
- [L3] This is the first study to demonstrate the significantly earlier age at which THA and TKA are required for overweight patients and those in obese category 1, in addition to those in obesity categories 2 and 3. [18] (10.1002/jor.24460)
- [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. [19] (10.1136/bjsports-2021-104754)
- [L1] An aggregate exercise programme energy expenditure (>10 000 kcal) may be required to promote reductions in intrahepatic fat. [20] (10.1136/bjsports-2016-096197)
- [L3] In this cohort of obese patients who underwent THA, the WHO obesity class was not associated with risk, invasiveness, or timing of reoperations. [21] (10.1016/j.arth.2025.07.026)
- [L3] Obese and overweight patients converted to THA at significantly higher rates compared with normal-weight patients. [22] (10.1177/03635465251400355)
- [L4] These results suggest that aging and obesity are both associated with a loss of the positive relationship between cartilage thickness and ambulatory loads, and that the relationship is dependent on the compartment and whether the load is generated by body size or subject-specific gait mechanics. [23] (10.1002/jor.22530)
- [L3] These findings suggest modern surgical practices and implant designs may have mitigated traditional obesity-related risks. [24] (10.1016/j.arth.2026.04.031)
- [Paper] The Arthritis Committee recognizes the profound importance of arthritic disorders to the general population, not only as a health problem, but for their social and economic impact. [25] (10.1016/s0363-5023(83)80245-7)
- [L3] At 2 years, obese patients demonstrated increased risks of malunion, nonunion, and revision. [26] (10.1016/j.injury.2025.112891)
- [L3] BMI has a weak-to-moderate association with peri-incisional adiposity in primary total joint arthroplasty patients. [27] (10.1016/j.arth.2024.08.020)
- [L3] However, obesity remains a critical risk factor for mechanical failures. [28] (10.1016/j.jisako.2025.100861)
- [L3] Obesity has an increased risk of all-cause revisions and revision for instability or dislocation in patients receiving rTSA indicated for fractures. [29] (10.1016/j.jse.2025.05.036)
- [L3] Semaglutide appears to be a safe alternative to bariatric surgery for weight management before THA, with similar implant survival and postoperative complication rates. [30] (10.1016/j.arth.2025.08.068)
- [L3] Women had decreased odds of losing greater than five pounds before surgery despite increased odds of having preoperative bariatric surgery. [31] (10.1016/j.arth.2026.06.021)
- [L4] Obesity substantially lengthened length of stay and encouraged undesirable discharge when compared to non-obese individuals. [32] (10.1186/s12891-025-09349-6)
- [L3] Based on AOANJRR data, obese patients are at increased risk of higher rate of revision following UKA. [33] (10.1177/2325967125s00336)
- [Paper] Obesity did not enhance cartilage degeneration in the absence of fracture or surgical trauma. [34] (10.1002/jor.24799)
- [L3] Unlike BMI, the STiB ratio reflects local anatomical factors that directly influence surgical exposure and wound healing. [35] (10.1016/j.arth.2025.09.022)
- [Paper] Adolescent murine obesity alters structural, mechanical and compositional properties of the bone, which may have lasting implication on bone health even after the obesity is corrected. [36] (10.1002/jor.25378)
- [L3] Our findings strongly suggest that the "Obesity Paradox" in major trauma is not a mere statistical anomaly, but a reproducible phenomenon with a distinct mechanistic explanation: Biomechanical protection, which results in a lower ISS, neutralizes the increased physiological and comorbidity burden of the obese state. [37] (10.1016/j.injury.2025.112913)
- [L1] Following MMPRT repair, repairs show progression of osteoarthritis with higher rates seen with elevated BMI. [38] (10.1002/arj.70028)
- [L4] These findings suggest that articular cartilage may not adapt to higher joint loads in adults with obesity. [39] (10.1002/jor.24655)
- [Paper] Diet-induced obesity significantly altered bone morphology and mineral density in a manner that was dependent on dietary free fatty acid content. [40] (10.1002/jor.24219)
- [Paper] This was supported by the observation that ACC inhibition ameliorated lipid accumulation in chondrocytes, thereby suggesting that ACC could potentially be targeted to treat obesity-associated OA. [41] (10.1002/jor.25322)
- [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. [42] (10.1016/j.jisako.2025.100927)
- [L4] Under weight-bearing conditions, contact areas increased by an average of 24% (p < 0.05). [43] (10.1016/j.orthres.2004.08.003)
- [L3] In morbidly obese patients, DM implants demonstrated excellent five-year survivorship with outcomes comparable or slightly superior to fixed-bearing constructs. [44] (10.1016/j.arth.2026.03.075)
- [L3] Hip arthroscopy for the treatment of FAI and labral tears in patients with obesity yielded significant and sustainable long-term improvements, which were equivalent to those of a benchmark matched control group of normal-weight patients. [45] (10.1177/03635465251392585)
- [L1] Total weight loss % was higher in bariatric surgery patients (28.7%, P < 0.001). [47] (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. [48] (10.1186/s12891-026-09722-z)
- [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. [50] (10.1016/j.arthro.2025.04.036)
- [L3] The ten-year functional outcomes and revision rates of THA do not justify restricting access to surgery on the basis of BMI. [51] (10.1016/j.arth.2025.07.044)
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