Early Survivorship and Clinical Outcomes of a Single-Peg Cementless Metal-Backed Patellar Component in Primary Total Knee Arthroplasty

Background Modern cementless metal-backed patellar components have re-emerged in total knee arthroplasty (TKA) with the goal of improving biologic fixation and implant survivorship. While contemporary multi-pegged cementless patellar designs have demonstrated promising outcomes, limited data exist regarding modern single-pegged cementless metal-backed patellar components. The purpose of this study was to evaluate early survivorship and clinical outcomes following implantation of a single-pegged cementless metal-backed patella in primary TKA. Methods A retrospective review was performed of 275 consecutive primary posterior-stabilized TKAs performed by a single surgeon between 2017 and 2023 utilizing a cementless single-pegged metal-backed patellar component. Primary outcomes included patellar component survivorship and revision. Secondary outcomes included anterior knee pain (AKP), manipulation under anesthesia (MUA), stiffness, infection, and return to the operating room. Results At 1-year follow-up, patellar component survivorship was 96.4%, with a 3.6% patellar component explantation rate. No patellar fractures or component dissociations were observed. AKP was reported in 25.7% of patients. MUA was required in 13.5% of patients, while lysis of adhesions occurred in 6.2%. Infection requiring irrigation and debridement occurred in 0.7% of patients. Exploratory subgroup analysis demonstrated higher rates of symptomatic anterior knee pain and patellar revision among female patients. Conclusions Modern single-pegged cementless metal-backed patellar components demonstrated acceptable short-term survivorship without patellar fracture or component dissociation at early follow-up. However, persistent anterior knee pain and symptomatic revision remained clinically relevant outcomes. Further comparative investigation evaluating modern cementless patellar designs and patient-specific patellofemoral morphology is warranted.