Elliot Sappey-Marinier1,2, Jobe Shatrov3,4,5, Cécile Batailler6,7, Axel Schmidt6, Elvire Servien6,8, Emmanuel Marchetti9, Sébastien Lustig6,7. 1. Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, 103 Grande Rue de la Croix-Rousse, 69004, Lyon, France. esappey@gmail.com. 2. Univ Lyon, Claude Bernard Lyon 1 University, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France. esappey@gmail.com. 3. Sydney Orthopaedic Research Institute, Chatswood, Sydney, Australia. 4. University of Notre Dame Australia, Sydney, Australia. 5. Hornsby and Ku-Ring Hospital, Sydney, Australia. 6. Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, 103 Grande Rue de la Croix-Rousse, 69004, Lyon, France. 7. Univ Lyon, Claude Bernard Lyon 1 University, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France. 8. LIBM - EA 7424, Interuniversity Laboratory of Biology of Mobility, Claude Bernard Lyon 1 University, Lyon, France. 9. Centre Orthopédique Fleming, 30 Avenue Alexandre Fleming, 38300, Bourgoin-Jallieu, France.
Abstract
PURPOSE: The purpose of the study was to compare clinical and radiological results between kinematic alignment (KA) and mechanical alignment (MA) with a posterior-stabilized (PS) total knee arthroplasty (TKA) with a post-cam mechanism at a minimum follow-up of 3 years. The authors hypothesized a higher risk of aseptic loosening when performing KA using PS TKA. METHODS: A retrospective monocentric single surgeon case control study was performed comparing 100 matched patients who had TKA performed using a MA philosophy to 50 patients receiving TKA with a KA technique between January 2016 and October 2017. All patients had the same knee prosthesis (GMK primary posterior-stabilized, Medacta®, Switzerland). Patient specific cutting blocks were used in both groups and a restricted KA (rKA) was aimed in the KA group. A hybrid cementation technique was performed. The new Knee Society Score (KSS) and radiological assessment were collected preoperatively and at the final follow-up. Comparisons between groups were done with the T test or Fisher exact test. Global survival curves were estimated with Kaplan-Meier model. Significance was set at p < 0.05. RESULTS: Mean follow-up was 42.9 months ± 3.6 (range 37.6-46.7) and 53.3 months ± 4.1 (range 45.5-59.8) for rKA and MA groups. Postoperatively, no significant differences were found for clinical scores between both groups. Radiological assessment found similar postoperative Hip-Knee-Ankle angle for rKA and MA groups (178° versus 179° respectively, NS). At last follow-up, a significant higher survivorship was found for the MA group compared to the rKA group (97 versus 84%; p < 0.001) for aseptic loosening revision as the endpoint. CONCLUSION: An increased risk of tibial implant loosening was found with rKA compared to MA using a posterior-stabilized TKA with a post-cam system at short-term follow-up. Caution should be taken when choosing the TKA design while performing rKA. LEVEL OF EVIDENCE: Retrospective case-control study, Level IV.
PURPOSE: The purpose of the study was to compare clinical and radiological results between kinematic alignment (KA) and mechanical alignment (MA) with a posterior-stabilized (PS) total knee arthroplasty (TKA) with a post-cam mechanism at a minimum follow-up of 3 years. The authors hypothesized a higher risk of aseptic loosening when performing KA using PS TKA. METHODS: A retrospective monocentric single surgeon case control study was performed comparing 100 matched patients who had TKA performed using a MA philosophy to 50 patients receiving TKA with a KA technique between January 2016 and October 2017. All patients had the same knee prosthesis (GMK primary posterior-stabilized, Medacta®, Switzerland). Patient specific cutting blocks were used in both groups and a restricted KA (rKA) was aimed in the KA group. A hybrid cementation technique was performed. The new Knee Society Score (KSS) and radiological assessment were collected preoperatively and at the final follow-up. Comparisons between groups were done with the T test or Fisher exact test. Global survival curves were estimated with Kaplan-Meier model. Significance was set at p < 0.05. RESULTS: Mean follow-up was 42.9 months ± 3.6 (range 37.6-46.7) and 53.3 months ± 4.1 (range 45.5-59.8) for rKA and MA groups. Postoperatively, no significant differences were found for clinical scores between both groups. Radiological assessment found similar postoperative Hip-Knee-Ankle angle for rKA and MA groups (178° versus 179° respectively, NS). At last follow-up, a significant higher survivorship was found for the MA group compared to the rKA group (97 versus 84%; p < 0.001) for aseptic loosening revision as the endpoint. CONCLUSION: An increased risk of tibial implant loosening was found with rKA compared to MA using a posterior-stabilized TKA with a post-cam system at short-term follow-up. Caution should be taken when choosing the TKA design while performing rKA. LEVEL OF EVIDENCE: Retrospective case-control study, Level IV.