Outcome following total knee replacement in patients with a previous patellectomy

Although patellectomy is a rarely performed surgical procedure, patients may still progress to develop osteoarthritis of the tibiofemoral compartments leading to total knee replacement surgery. Due to the mechanical disadvantage of a previous patellectomy, it has previously been suggested that a prosthesis with more constraint should be used, however, there are conflicting reports in the literature. We aimed to assess the effects of stability following total knee replacement in patellectomised knee with revision as a primary endpoint. We reviewed the outcome of 25 total knee replacements in our institution in patients with a previous patellectomy. Ten were posterior stabilised and 15 minimally stabilised (including those with a 'deep dish'). Five of the patients in the minimally stabilised group underwent revision surgery, and 3 of these were early revision due to instability. None of the patients in the posterior stabilised group underwent revision. We conclude that when a total knee replacement is performed in a patient with a previous patellectomy a posterior stabilised implant should be used.