The effect of patella resurfacing in total knee arthroplasty on functional range of movement measured by flexible electrogoniometry

BackgroundThe need for patella resurfacing remains an area of considerable controversy in total knee replacement surgery. There would appear to be no reported evidence on the effect of patella resurfacing on knee function, as measured by functional range of movement used in a series of tasks, in patients undergoing knee replacement. The object of this study was to measure knee joint motion during functional activities both prior to and following total knee replacement in a randomised group of patients with and without patella resurfacing and to compare these patient groups with a group of normal age-matched subjects.MethodsThe study design was a double blinded, randomised, prospective, controlled trial. The knee joint functional ranges of movement of a group of patients (n = 50, mean age = 70 years) with knee osteoarthritis were investigated prior to and following total knee arthroplasty (4 months and 18–24 months) along with a group of normal subjects (n = 20, mean age = 67). Patients were randomly allocated into two groups, those who received patella resurfacing (n = 25) and those who did not (n = 25). Flexible electrogoniometry was used to measure the flexion–extension angle of the knees with respect to time in eleven functional activities.FindingsNo statistically significant differences (alpha level 0.05) in joint excursion of the affected knee were found between patients who received patella resurfacing and those who did not.InterpretationRoutine patella resurfacing in a typical knee arthroplasty population does not result in an increase in the functional range of movement used after knee replacement.