The Effect of Body Mass Index on Functional Outcome of Patients With Knee Replacement

Abstract

Objective To investigate the effects of body mass index (BMI) on the rehabilitation process in patients with a recent knee replacement. Design This retrospective cohort study included all patients admitted to a rehabilitation hospital, with a recent diagnosis of knee replacement and available hospital admission data including height and weight, between 2014 and 2017. Setting Rehabilitation hospital. Participants Study participants included patients who had undergone knee replacement surgery (N=742), with available BMI data. Interventions None. Main Outcome Measures FIM scores, including FIM change per day (FIM efficiency) by BMI category. Results The chart review identified 742 patients who had undergone knee replacement surgery, with available BMI data. The identified patients ranged in age from 58 to 85 years, with a mean age of 70 years. Of the patients included in the study, 24 were male, 49 were female, 73 were within the normal weight class, 180 in the overweight class, 189 in the obese class I, 143 in the obese class II, and 157 patients were classified as obese class III. The mean FIM efficiency was highest in the obese class II category (3.96). In a multivariate analysis after controlling for age, obese classes II and III had significantly better FIM efficiency. Conclusion This study did not demonstrate that obesity adversely affects the rate of recovery during hospitalization after knee replacement surgery.

Greater risk of all‐cause revisions and complications for obese patients in 3 106 381 total knee arthroplasties: a meta‐analysis and systematic review

“…One additional article was identified from citation search and 210 full‐text articles were assessed for eligibility. Finally, 91 studies were included, with 22 prospective, 4,7,8,16,22–39 54 retrospective, 6,9–12,14,15,17,40–85 and 15 case‐controlled studies 5,13,18,19,86–96 …”

“…There was 68.8% ( n = 239 897 of 348 585) females in the obese group and 62.9% ( n = 522 543 of 830 959) females in the non‐obese group. Fifty‐eight studies reported mean age at index TKA for both groups, ranging from 59.6 66 to 71.5 years 11 in the obese group, and from 58.0 93 to 74.6 years 44 in the non‐obese group.…”

“…This increases external validity and applicability to the general population 97 . Although there has been a recent analysis by Chaudhry, 98 this was performed with articles only until August 2016 and, since then, there have been several high statistically powered studies published, of which some had varying conclusions 11,12,23,25,28,34,39,44,47,51,58,59,71,75,77,82,85 . Furthermore, Chaudhry 98 only focused on all‐cause, aseptic and septic revision risks and did not investigate other complications and peri‐operative parameters.…”

Influence of body mass index on early post-operative functional outcomes after total knee arthroplasty: A prospective, clinical and observational study

“…25,26 Several additional studies, however, have shown that regardless of BMI category, individuals had similar or equivocal outcomes following TKA. [28][29][30] Furthermore, it is still unknown if BMI affects early phase mobility outcomes and functions during post-TKA rehabilitation. As a result, the current study investigated the effect of BMI on early phase mobility and functional outcome during post-TKA rehabilitation.…”

The effect of body mass index on functional outcome of patients with knee arthroplasty with and without hip abductor muscle strengthening: six months Follow-Up of a Randomized Pilot Study.

“…because of such reasons surgery is postponed till the weight reduction is achieved. The guidelines of American academy of orthopaedic surgeons and United Kingdom National Health Service suggest caution and rejection of surgery should be based on BMI (Burke et al, 2019b).…”