Progressive Rehabilitation Following Total Knee Arthroplasty (PROG)

• Change from baseline in Stair climbing test (SCT) [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  Time to ascend and descend one flight of stairs
  
  

• Change from baseline in Timed-up-and-go Test (TUG) [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  
• Change from baseline in 6-minute walk test (6MW) [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  
• Change from baseline in muscle strength [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  Isometric quadriceps and hamstrings strength.
  
  
• Change from baseline in self-reported health status [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  WOMAC and SF-12
  
  
• Change from baseline in muscle activation [ Time Frame: pre operatively (average of two weeks before surgery), change from baseline at 1, 2, 3, 6 and 12 months ] [ Designated as safety issue: No ]
  Doublet interpolation for quadriceps activation.
  
  

Over 500,000 total knee arthroplasties (TKAs) are performed each year in the United States to alleviate pain and disability associated with knee osteoarthritis (OA), and this number is expected to grow to 3.48 million per year by the year 2030. TKA reduces pain and improves self-reported function compared to pre-operative levels, but post-operative deficits in walking speed (20% slower) and stair climbing speed (50% slower) can persist for years. Stair climbing performance is the single largest residual deficit after TKA with seventy-five percent of TKA patients reporting difficulty negotiating stairs after surgery. Collectively, these findings suggest that current rehabilitation does not adequately target the impairments that lead to long-term deficits in functional mobility after TKA.

The aim of the proposed trial is to evaluate the effectiveness of a progressive resistance rehabilitation program (PROG) after TKA compared to a traditional rehabilitation program (TRAD). The PROG intervention will involve intensive rehabilitation using progressive resistance exercise and faster progression to functional strengthening exercises. The TRAD intervention represents the synthesis of previously published TKA rehabilitation programs. Our preliminary data suggest that the PROG intervention has low risk and results in improved functional mobility and muscle strength. The investigators will measure function and strength at six time points (pre-op; 1, 2, 3, 6, and 12 months after TKA). The investigators will also evaluate the contribution of changes in muscle mass (atrophy/hypertrophy) and central activation to changes in muscle strength following PROG and TRAD interventions.