Trabecular Metal Augmentation for Patellar Resurfacing in Primary Total Knee Arthroplasty with Severe Patellar Bone Deficiency: A Case Series

Background: Management of severe patellar bone deficiency during primary total knee arthroplasty (TKA) remains a technically demanding and controversial aspect of knee reconstruction.Conventional patellar resurfacing in patellae with residual thickness less than 10 mm is associated with an increased risk of fracture, component loosening, and extensor mechanism dysfunction.Although trabecular metal (TM) augmentation has demonstrated reliable fixation in revision TKA, evidence supporting its role in primary TKA is limited.Materials and methods: This retrospective case series reviewed 10 patients (12 knees) who underwent primary TKA with TM patellar augmentation for severe patellar bone deficiency (residual patellar thickness <10 mm).All procedures were performed by a single arthroplasty surgeon at a tertiary referral center.Clinical outcomes were assessed using the Oxford knee score (OKS), forgotten joint score (FJS), and knee range of motion (ROM).Radiographic evaluation assessed patellar component fixation, alignment, and migration.The mean follow-up was 37.8 months (range, 12-79 months).Results: All patients were female, with a mean age of 72.8 years (range, 59-81 years).The mean residual patellar thickness prior to reconstruction was 5.4 mm.Composite patellar thickness was restored to 20-24 mm in all knees.No intraoperative patellar fractures, extensor mechanism complications, or postoperative patellar component loosening were observed.At the final follow-up, the mean OKS was 40.8, the mean FJS was 70.6, and the mean ROM was 0-121.Implant survivorship was 100%, with no reoperations or revisions.Conclusions: Trabecular metal augmentation for patellar resurfacing in primary TKA provides reliable restoration of patellar thickness and patellofemoral biomechanics in severely deficient patellae, with excellent short-to mid-term functional and radiographic outcomes.