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.

Sciatic Nerve Palsy following Total Hip Replacement via Direct Anterior Approach after Recommencement of Warfarin for Prophylaxis in Atrial Fibrillation.

The occurrence of sciatic nerve palsy following posterior and anterolateral approaches to the hip has been well documented and is about 1-2%. To our knowledge, however, there are no reports of sciatic nerve palsy occurring secondary to the anterior approach to the hip for arthroplasty. We describe a case of sciatic nerve palsy secondary to haematoma formation following total hip replacement through the anterior approach. The recommencement of warfarin for prophylaxis against atrial fibrillation is thought to have been a contributing factor. Full recovery is rare following delayed diagnosis and early recognition of the signs of pain, parasthesia, and gradual loss of dorsiflexion and prompt drainage may reverse the condition. We advise caution with restarting warfarin following total hip arthroplasty.