Lower revision rates for cemented fixation in a long-term survival analysis of three different LCS designs.

BACKGROUND: In primary Total Knee Arthroplasty (TKA), it is still not clear if cemented or uncemented fixation has the best long-term survival. The Low Contact Stress (LCS) mobile-bearing (MB) knee system was introduced in 1977. The aim of this study is to investigate the long-term survival of this design with a minimum of 15-year follow-up. METHODS: A retrospective analysis was performed, with the primary endpoint for survival defined as revision. Cox regression analysis was performed to assess the association between type of fixation and the risk of revision, while correcting for potential confounders (diagnosis, design, age and sex). RESULTS: 1271 cases were included with inflammatory joint disease (IJD) (657 cases) and non-IJD (614 cases). TKAs were performed cemented in 522 cases and uncemented in 749 cases. A bicruciate retaining design was used in 180 cases, a rotating platform design in 174 cases and an anterior posterior glide posterior cruciate-retaining (PCR) design in 916 cases. Cumulative incidence of component revision at 15 years was 2.7% (95% CI 1.6; 4.5) for cemented and 10% (95% CI 8.1; 12.4) for uncemented TKA, respectively. The 20-year cumulative incidence was 2.9% (95% CI 1.7; 4.7) for cemented and 10.9% (95% CI 8.8; 13.4) for uncemented TKA, respectively. Age, non-IJD and PCR design were associated with a significantly higher risk of revision, regardless of the type of fixation. CONCLUSION: Long-term survival for patients undergoing cemented or uncemented TKA using the LCS MB system revealed lower revision rates for cemented fixation. Revision risk was higher in younger, non-IJD patients who had the PCR design, regardless of the type of fixation. For the LCS MB TKA design, it is recommended to use cemented fixation.

Influence of Preoperative Tibiotalar Alignment in the Coronal Plane on the Survival of Total Ankle Replacement: A Systematic Review.

BACKGROUND: It remains controversial whether significant preoperative tibiotalar varus and valgus deformity should be contraindications for total ankle replacement (TAR). The primary aim of this systematic review was to analyze the influence of preoperative tibiotalar varus and valgus alignment on the survival of TAR. METHODS: The databases MEDLINE and Embase were searched from onset through September 2018. Two authors performed study selection and data extraction using a predefined data extraction tool. Implant survival in the alignment groups was reported as "revisions per 100 component years." Additional procedures, complications, and revisions were also reported. Assessment of the methodological quality was performed using the Newcastle-Ottawa Scale (NOS). RESULTS: In total, 17 studies were considered eligible, in which a total of 1692 TARs were included from 1627 patients. The weighted mean follow-up was 52.4 (range, 1-147) months. The neutral alignment group included 711 TARs, the varus group included 545 TARs, and the valgus group included 332 TARs. Total revisions were 52, 37, and 36 in the preoperative tibiotalar neutral, varus, and valgus alignment groups, respectively. Revisions per 100 observed component years were 1.6, 1.7, and 2.5 in the preoperative tibiotalar neutral, varus, and valgus alignment groups, respectively. A total of 129 complications and 447 additional procedures were reported in 601 TARs. CONCLUSION: There was a strong indication that preoperative varus alignment in the coronal plane had a comparable implant survival to neutral alignment. Preoperative valgus alignment demonstrated a more negative influence on implant survival. LEVEL OF EVIDENCE: Level III, systematic review.