Risk of Postoperative Stiffness Following Multiligamentous Knee Injury Surgery Is Not Affected by Obesity: A Multicenter Study


      The purpose of this study was to examine the relationship between obesity and postoperative stiffness following surgical management of multiligamentous knee injuries (MLKIs) using a large two-center cohort, by both 1) using binary cutoffs at various body mass indexes (BMIs) and 2) a linear regression model.


      190 consecutive patients who underwent surgical management of MLKIs between January 2001 and March 2020 were reviewed at two level 1 academic trauma centers. Patient demographics, surgical characteristics, and manipulation under anesthesia (MUA)/lysis of adhesions (LOA) were reviewed. Patients were stratified by obesity grades: grade 1 (BMI 30 to <35) grade 2 (BMI 35 to <40); grade 3 (BMI >40), and compared with a nonobese comparison group with BMI <30. Multivariate logistic regressions were performed, including the covariates of age, gender, BMI, acute versus chronic injury, external fixator, vascular injury, knee dislocation, and Schenck Classification. Fisher’s exact test was used to compare rate of MUA between grades of obesity. Analyses were performed with R. Statistical significance was set at P < .05.


      The mean BMI of the cohort was 29.2 kg/m2. The mean overall follow-up was 27.2 ± 7.2 months (range: 14–142 months). There were 55 (29.1%) MUA procedures observed at a mean 3.77 ± 2.18 months (range: 1.8–9.7 months) after final MLKI surgery. No significant difference was found in BMI of patients who underwent a MUA compared to patients who did not (30.2 vs 28.8; P = .67). There was no significant difference in rate or time to MUA following MLKI surgery between groups, with logistic regression demonstrating no significance (P = .144). Use of external fixation at the index surgery (OR = 3.3 [95% CI: 2.2, 4.7; P < .0001]) and vascular injury (OR = 6.2 [95% CI: 1.8, 24.5; P = .005]) were found to be independent predictors for need for MUA.


      No difference in risk for postoperative stiffness requiring MUA following surgery for MLKI was found based on BMI. At all BMI levels, there were no significant increase in need for postoperative MUA, suggesting at minimum a neutralizing effect of obesity on postoperative stiffness. In addition, patients with external fixator use and vascular injury at index surgery were found to be at significantly higher risk for postoperative stiffness requiring MUA following surgery for MLKI. Surgeons should be aware of the risk factors for arthrofibrosis when proceeding with surgical repair or reconstruction of two or more ligaments of the knee.

      Level of Evidence

      III, multicenter retrospective cohort study.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Mook W.R.
        • Ligh C.A.
        • Moorman C.T.
        • Leversedge F.J.
        Nerve injury complicating multiligament knee injury: current concepts and treatment algorithm.
        J Am Acad Orthop Surg. 2013; 21: 343-354
        • Schenck R.C.
        The dislocated knee.
        Instr Course Lect. 1994; 43: 127-136
        • Ridley T.J.
        • Cook S.
        • Bollier M.
        • et al.
        Effect of body mass index on patients with multiligamentous knee injuries.
        Arthroscopy. 2014; 30: 1447-1452
        • Werner B.C.
        • Gwathmey F.W.
        • Higgins S.T.
        • Hart J.M.
        • Miller M.D.
        Ultra-low velocity knee dislocations: Patient characteristics, complications, and outcomes.
        Am J Sports Med. 2014; 42: 358-363
        • Lian J.
        • Patel N.K.
        • Nickoli M.
        • et al.
        Obesity is associated with significant morbidity after multiligament knee surgery.
        J Knee Surg. 2020; 33: 525-530
        • Lynch A.D.
        • Chmielewski T.
        • Bailey L.
        • et al.
        Current concepts and controversies in rehabilitation after surgery for multiple ligament knee injury.
        Curr Rev Musculoskelet Med. 2017; 10: 328-345
        • Hanley J.
        • Westermann R.
        • Cook S.
        • et al.
        Factors associated with knee stiffness following surgical management of multiligament knee injuries.
        J Knee Surg. 2017; 30: 549-554
        • Cook S.
        • Ridley T.J.
        • McCarthy M.A.
        • et al.
        Surgical treatment of multiligament knee injuries.
        Knee Surg Sports Traumatol Arthrosc. 2015; 23: 2983-2991
        • Bodendorfer B.M.
        • Keeling L.E.
        • Michaelson E.M.
        • et al.
        Predictors of knee arthrofibrosis and outcomes after arthroscopic lysis of adhesions following ligamentous reconstruction: A retrospective case-control study with over two years’ average follow-up.
        J Knee Surg. 2019; 32: 536-543
        • Saini P.
        • Trikha V.
        Manipulation under anesthesia for post traumatic stiff knee-pearls, pitfalls and risk factors for failure.
        Injury. 2016; 47: 2315-2319
        • Kahan J.B.
        • Schneble C.A.
        • Li D.
        • et al.
        Increased neurovascular morbidity is seen in documented knee dislocation versus multiligamentous knee injury.
        J Bone Joint Surg Am. 2021; 103: 921-930
        • Flegal K.M.
        • Kit B.K.
        • Orpana H.
        • Graubard B.I.
        Association of all-cause mortality with overweight and obesity using standard body mass index categories.
        JAMA. 2013; 309: 71-82
        • Usher K.M.
        • Zhu S.
        • Mavropalias G.
        • Carrino J.A.
        • Zhao J.
        • Xu J.
        Pathological mechanisms and therapeutic outlooks for arthrofibrosis.
        Bone Res. 2019; 7
        • Park W.
        • Ramachandran J.
        • Weisman P.
        • Jung E.S.
        Obesity effect on male active joint range of motion.
        Ergonomics. 2010; 53: 102-108
        • Jeong Y.
        • Heo S.
        • Lee G.
        • Park W.
        Pre-obesity and obesity impacts on passive joint range of motion.
        Ergonomics. 2018; 61: 1223-1231
        • Stevens-Lapsley J.E.
        • Kohrt W.M.
        Osteoarthritis in women: Effects of estrogen, obesity and physical activity.
        Womens Health (Lond Engl). 2010; 6: 601-615
        • Romani W.
        • Patrie J.
        • Curl L.A.
        • Flaws J.A.
        The correlations between estradiol, estrone, estriol, progesterone, and sex hormone-binding globulin and anterior cruciate ligament stiffness in healthy, active females.
        J Womens Health (Larchmt). 2003; 12: 287-298
        • Shultz S.J.
        • Kirk S.E.
        • Johnson M.L.
        • Sander T.C.
        • Perrin D.H.
        Relationship between sex hormones and anterior knee laxity across the menstrual cycle.
        Med Sci Sports Exerc. 2004; 36
        • Park S.K.
        • Stefanyshyn D.J.
        • Loitz-Ramage B.
        • Hart D.A.
        • Ronsky J.L.
        Changing hormone levels during the menstrual cycle affect knee laxity and stiffness in healthy female subjects.
        Am J Sports Med. 2009; 37: 588-598
        • Maruyama S.
        • Yamazaki T.
        • Sato Y.
        • et al.
        Relationship between anterior knee laxity and general joint laxity during the menstrual cycle.
        Orthop J Sports Med. 2021; 92325967121993045
        • Spindler K.P.
        • Huston L.J.
        • et al.
        • MOON Knee Group
        Ten-year outcomes and risk factors after anterior cruciate ligament reconstruction: A MOON longitudinal prospective cohort study.
        Am J Sports Med. 2018; 46: 815-825
        • Pietrosimone B.
        • Kuenze C.
        • Hart J.M.
        • et al.
        Weak associations between body mass index and self-reported disability in people with unilateral anterior cruciate ligament reconstruction.
        Knee Surg Sports Traumatol Arthrosc. 2018; 26: 1326-1334
        • Patel N.M.
        • Talathi N.S.
        • Bram J.T.
        • DeFrancesco C.J.
        • Ganley T.J.
        How does obesity impact pediatric anterior cruciate ligament reconstruction?.
        Arthroscopy. 2019; 35: 130-135
        • Wilson S.M.
        • Mehta N.
        • Do H.T.
        • Ghomrawi H.
        • Lyman S.
        • Marx R.G.
        Epidemiology of multiligament knee reconstruction.
        Clin Orthop Relat Res. 2014; 472: 2603-2608
        • Qin C.
        • Roth C.
        • Lee C.
        • Athiviraham A.
        National trends, 90-day readmission and subsequent knee surgery following multi-ligament knee reconstruction.
        J Orthop. 2020; 21: 49-52
        • Natsuhara K.M.
        • Yeranosian M.G.
        • Cohen J.R.
        • Wang J.C.
        • McAllister D.R.
        • Petrigliano F.A.
        What is the frequency of vascular injury after knee dislocation?.
        Clin Orthop Relat Res. 2014; 472: 2615-2620
        • Chowdhry M.
        • Burchette D.
        • Whelan D.
        • Nathens A.
        • Marks P.
        • Wasserstein D.
        Knee dislocation and associated injuries: an analysis of the American College of Surgeons National Trauma Data Bank.
        Knee Surg Sports Traumatol Arthrosc. 2020; 28: 568-575
        • Bernhoff K.
        • Michaëlsson K.
        • Björck M.
        Incidence and outcome of popliteal artery injury associated with knee dislocations, ligamentous injuries, and close to knee fractures: A nationwide population based cohort study.
        Eur J Vasc Endovasc Surg. 2021; 61: 297-304