Radiographic False Evidence of a Tibial Baseplate Fracture After Total Knee Arthroplasty.

Fracture of the tibial baseplate is a rare but dramatic cause of typically late fatigue failure in the setting of loosening after total knee arthroplasty. A 58-year-old female presented 4 months after total knee arthroplasty for evaluation of contralateral knee pain. Plain radiographs of the left knee incidentally suggested the possibility of tibial baseplate fracture despite minimal, expected postoperative symptoms. Subsequent computed tomography imaging demonstrated no confirmatory evidence of component failure or fracture. Malalignment and fatigue fracture are proposed etiologies of baseplate fractures. The presented case illustrates the importance of computed tomography imaging and clinical correlation when a diagnosis of baseplate fracture is suspected to avoid an unnecessary revision surgery.

Posterior Interosseous Nerve Proximity to Cortical Button Implant for Distal Biceps Repair With Single and 2-Incision Approaches.

PURPOSE: Fixation with a cortical button is the biomechanically strongest surgical approach for distal biceps repair, and utilization of the 2-incision approach may provide a more anatomical repair and improved terminal supination strength. The risk of injury to the posterior interosseous nerve (PIN) associated with this approach requires further investigation. METHODS: A distal biceps repair with a cortical button was performed on 10 cadavers, 5 utilizing the single-incision approach and 5 utilizing the 2-incision approach. Contrast was injected into the radial nerve and computed tomography scans were obtained. The distance between the drilled cortical perforation and the PIN was measured. RESULTS: The mean distance from the cortical perforation to the PIN was not significantly different between approaches (9.4 mm and 8.8 mm). A PIN entrapment was seen in 0 out of 5 for the single-incision approach and 1 out of 5 for the 2-incision approach. CONCLUSIONS: Distal biceps repair with cortical button fixation places the PIN at risk of injury regardless of the approach used. Methods of fixation that require bicortical drilling should be especially avoided when using the 2-incision approach. CLINICAL RELEVANCE: Distal biceps repair utilizing bicortical drilling for fixation through a 2-incision approach poses high risk of injury to the PIN and should be avoided.