An evaluation of the influence of force- and weight bearing (a)symmetry on patient reported outcomes after total knee arthroplasty

Acta Orthop Belg. 2020 Jun;86(2):294-302.


It has been reported that balance impairments and asymmetrical movement patterns occur in patients after total kne arthroplasty (TKA). The purpose of this study was to evaluate if force- and weight-bearing asymmetry correlate with patient-reported outcomes (PROMs). Twenty patients were prospectively analysed up to 6 months after TKA. Quadriceps- and hamstring force were measured using a hand-held dynamometer. Vertical ground reaction forces during sit-to-stand, stair descending and squatting were assessed by force plates. Patients were asked to complete the KOOS, OKS and 2011 KSS. The symmetry-ratios during sit-to-stand, squat and stair-descent improved significantly. Preopera-tive quadriceps-force was positively correlated with KOOS-Symptoms (r=0.583, p=0.037). The pre-operative load-symmetry ratio during STS was negatively correlated with improvement in KOOS Pain (r=-0.675, p=0.011) and Symptoms (r=-0.674, p=0.008). In deep flexion, preoperative bodyweight ratio was positively correlated with postoperative OKS (r=0.601, p=0.039), KSS-Satisfaction (r=0.675, p=0.011) and improvement in KSS-Satisfaction (r=0.684, p=0.029). Weight bearing and force asymmetry do exist before TKA and take up to at least 6-months to fully recover. The more symmetry in muscle-force and weight-bearing is found preoperatively, the better the PROMs will be at 6 months after surgery.

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee* / adverse effects
  • Arthroplasty, Replacement, Knee* / methods
  • Arthroplasty, Replacement, Knee* / rehabilitation
  • Exercise Therapy / methods*
  • Female
  • Hamstring Muscles / physiopathology
  • Humans
  • Knee Joint / physiopathology
  • Knee Joint / surgery
  • Male
  • Muscle Strength Dynamometer
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / surgery*
  • Outcome Assessment, Health Care / methods*
  • Patient Reported Outcome Measures*
  • Postoperative Complications* / diagnosis
  • Postoperative Complications* / physiopathology
  • Postoperative Complications* / rehabilitation
  • Postural Balance
  • Quadriceps Muscle / physiopathology
  • Range of Motion, Articular
  • Stair Climbing
  • Treatment Outcome
  • Weight-Bearing