RESUMEN
BACKGROUND: Two related recent reports described high error rates for implant positioning and reduced implant survivorship in manual unicompartmental knee arthroplasty (MUKA) compared to robotic-assisted unicompartmental knee arthroplasty (RUKA). The present study scientifically replicated these reports by comparing MUKAs similarly performed by an experienced high-volume surgeon in similar patients using the same study methods as these reports. METHODS: A total of 216 consecutive MUKAs were retrospectively evaluated radiographically for achievement of implant positioning targets. Achievement of targets was compared to the published MUKA and RUKA outcomes and correlated with revision rates and patient-reported outcome measures. RESULTS: There were 20% of study MUKAs compared to 88.1% of comparison MUKAs (P < .001) and 31.4% of comparison RUKAs (P < .048) that failed to meet all 7 implant positioning targets. The MUKA revision rates were significantly lower in the study sample than for comparison MUKAs (3.2% versus 14.2%, P < .001). Implant survivorship was 91.7% (95% confidence interval 84.9, 98.5%) at 8.9 years compared to 70.0% (95% confidence interval 56.0, 80.0%) at 10.2 years, respectively. Most patient-reported outcome measures did not differ based on achievement of implant positioning targets (P ≥ .072). CONCLUSIONS: Present study findings indicate that observations in the 2 recent reports may not be generalizable to all UKA surgeons. Additional data on the relationship between implant positioning and revision as well as functional outcomes are needed to identify appropriate robotic arthroplasty applications.
Asunto(s)
Artroplastia de Reemplazo de Rodilla , Prótesis de la Rodilla , Osteoartritis de la Rodilla , Procedimientos Quirúrgicos Robotizados , Humanos , Artroplastia de Reemplazo de Rodilla/métodos , Estudios Retrospectivos , Supervivencia , Osteoartritis de la Rodilla/cirugía , Procedimientos Quirúrgicos Robotizados/métodos , Medición de Resultados Informados por el Paciente , Resultado del Tratamiento , Articulación de la Rodilla/cirugíaRESUMEN
PURPOSE: Revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) is technically demanding but can be performed with computer navigation system guidance. The purpose of this study was (1) to compare the outcomes of revision of UKA to TKA to those of primary TKA and (2) to describe a surgical technique for the revision of UKA to TKA using a navigation system. METHODS: From May 2011 to April 2014, a total of 298 knees underwent primary navigation-assisted TKA (group 1), and navigation-assisted UKA revision to TKA was performed in 15 patients (group 2). One to three propensity score matching was performed to compare the two groups after a minimum of three years of follow-up. Radiographic and clinical outcomes in addition to radiolucent lines were evaluated during follow-up. RESULTS: In group 1, there was one case that required metal block augmentation with the long stem under the tibial plate due to severe bone loss, while in other cases, short stems were used, and cement and autogenous bone grafts were used to fill bone defects due to minimal bone loss. Pre- and post-operative outcomes were significantly improved in both groups (p < 0.001). There were no statistical differences between groups in pre- and post-operative outcomes except post-operative Knee Society Function Score (KSFS) (p = 0.008). There were no radiolucent lines in the tibia or femur in either group during follow-up. CONCLUSIONS: With the use of an appropriate surgical technique, navigation-assisted revision of UKA to TKA can yield clinical and radiologic outcomes comparable to those of primary navigation-assisted TKA. LEVEL OF EVIDENCE: Level IV.