Body mass index and functional mobility outcome following early rehabilitation after a total knee replacement: a retrospective study in Taiwan

Arthritis Care Res (Hoboken). 2015 May;67(6):799-808. doi: 10.1002/acr.22474.


Objective: Obesity is associated with an increased risk of osteoarthritis, and the incidence of obese patients requiring a total knee replacement (TKR) has increased in recent years. A high body mass index (BMI) may influence post-TKR rehabilitation outcomes. We investigated the effects of obesity on functional mobility outcomes following post-TKR rehabilitation in Asian patients whose BMIs were not as high as those reported in similar studies performed in non-Asian countries.

Methods: A total of 113 patients were categorized as normal weight (n = 23), overweight (n = 32), class I obese (n = 31), or class II/III obese (n = 27). Patients were retrospectively followed up for 6 months after undergoing TKR followed by 2 months of active rehabilitation. Outcome measures were recorded at baseline and at the 2-month and 6-month followup assessments and included the Western Ontario and McMaster Universities Osteoarthritis Index and the following tests: functional reach, single-leg stance, ten-meter walk, timed up and go, chair rise, and stair climbing.

Results: A 4 × 3 (group × time) repeated-measures analysis of variance showed significant improvement in all of the outcome measures for all of the BMI groups at the 2-month and 6-month followup assessments (P < 0.05 for all). No significant intergroup differences at the 2-month and 6-month followup assessments were observed for any of the mobility measures except the functional reach and single-leg stance (P < 0.05).

Conclusion: Patients with class II/III obesity benefit from early post-TKR outpatient rehabilitation and respond as well as patients with lower BMIs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / adverse effects
  • Arthroplasty, Replacement, Knee / rehabilitation*
  • Asians
  • Biomechanical Phenomena
  • Body Mass Index*
  • Disability Evaluation
  • Female
  • Humans
  • Knee Joint / physiopathology
  • Knee Joint / surgery*
  • Male
  • Middle Aged
  • Obesity / complications*
  • Obesity / diagnosis
  • Obesity / ethnology
  • Obesity / physiopathology
  • Osteoarthritis, Knee / diagnosis
  • Osteoarthritis, Knee / ethnology
  • Osteoarthritis, Knee / etiology
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / surgery*
  • Recovery of Function
  • Retrospective Studies
  • Risk Factors
  • Severity of Illness Index
  • Taiwan / epidemiology
  • Time Factors
  • Treatment Outcome