Lower limb strength following total knee arthroplasty: a systematic review

Total knee arthroplasty (TKA) is commonly performed for end-stage knee osteoarthritis to relieve pain and improve quality of life. Understanding specific muscle weakness following TKA is required in order to develop targeted rehabilitation programmes for TKA patients. The aim of this systematic review was to determine whether TKA patients have reduced strength in lower limb muscle groups compared to controls.

A search of common scientific databases was conducted. A modified published checklist was used to assess the risk of bias. A meta-analysis was completed for each lower limb muscle group in three separate post-operative time periods (4-6 months, 1-3 years, and >3 years). The GRADE approach was used to determine the quality of the evidence.

Fifteen studies met the inclusion criteria for this review. There was low quality evidence for all meta-analyses. The meta-analyses showed that TKA patients had weaker quadriceps than the controls at every post-operative time (pooled effect sizes between -2.81 and -0.53). The meta-analyses of hamstring strength for patients 1-3 years post-operatively also showed patient weakness (pooled effect size=-1.87) and no significant difference at >3 years post-operatively (pooled effect size=-0.20).

There was low quality evidence of quadriceps and hamstring weakness following TKA. Further research is required to determine if other lower limb muscles also display similar muscle weakness. Strategies that specifically target strengthening of these muscle groups may need to be incorporated in rehabilitation to improve outcomes from TKA.

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