ABSTRACT
BACKGROUND: Preoperative planning is an integral aspect of managing complex deformity in reverse shoulder arthroplasty (RSA). The purpose of this study was to compare the success of patient specific instrumentation (PSI) and 3D computer-assisted planning with standard instrumentation (Non-PSI) in achieving planned corrections of the glenoid among patients undergoing RSA with severe bony deformity requiring glenoid bone grafts. METHODS: A retrospective case-control study was performed, including all patients that underwent RSA with combined bone grafting procedures (BIO-RSA or structural bone grafting) for severe glenoid deformity by a single between June 2016 and July 2023. Patients were required to have preoperative and postoperative CT scans as well as preoperative 3D planning performed for inclusion. Patients were divided into two groups based on the use of 3D computer-assisted planning with or without PSI (PSI vs. Non-PSI). The corrected inclination and version were measured by two separate reviewers on preoperative and postoperative 2D CT scans and compared to their corresponding preoperative planning goals utilizing bivariate analyses. RESULTS: We identified 45 patients that met our inclusion criteria (22 PSI and 23 Non-PSI). Preoperative inclination (mean ± SD) (PSI 10.12° ± 15.86°, Non-PSI 9.43° ± 10.64°; P = 0.864) and version (PSI -18.78° ± 18.3°, Non-PSI -17.82° ± 11.49°; P = 0.835) measurements were similar between groups. No significant differences in the mean deviation (error) between the postoperative and planned inclination (PSI 5.49° ± 3.72; Non-PSI 6.91° ± 5.05; P = 0.437) and version (PSI 8.37° ± 5.7; Non-PSI 5.37° ± 4.43; P = 0.054) were found between groups. No difference in the rate of outliers (>10° error) was noted in inclination (P = 0.135) or version (P = 0.445) between groups. Greater planned version correction was correlated with greater error when PSI was utilized (PSI r = 0.519, P = 0.013; Non-PSI r = 0.362, P = 0.089). CONCLUSION: Both PSI and 3D computer-assisted planning without PSI (Non-PSI) appear to be useful techniques to achieve version and inclination correction among patients undergoing RSA with severe glenoid deformity required glenoid bone grafting with no clear superiority of one method over the other. Surgeons should be aware that when utilizing PSI, slightly greater error in achieving version goals may occur as version correction is increased.
ABSTRACT
BACKGROUND: Tibial component aseptic loosening remains problematic in primary total knee arthroplasty (TKA). Influential factors include component design, metallurgy, and cement technique. Additionally, reports advocate for longer tibial stem fixation in high body mass index (BMI) patients. We have utilized a single stem length modular titanium baseplate in patients regardless of BMI, bone quality, or malalignment. We report the survivorship of this implant with focus on the impact of elevated BMI and postoperative malalignment. METHODS: We retrospectively reviewed patients who underwent TKA with a single modular titanium baseplate with a cruciate-shaped keel between 2004 and 2018. In total, 2,949 TKAs with a minimum of 1-year follow-up were included. The mean follow-up was 7 years. The primary outcome was component failure stratified by BMI and postoperative malalignment. High viscosity cement was utilized in all cases. Chi-squared and t-tests were used to compare outcome variables across groups. RESULTS: Eighty-five implants (2.8%) were revised with 46 (1.6%) for aseptic loosening. Failure was not associated with BMI, gender, American Society of Anesthesiologists class, or Charlson Comorbidity Index. There was no difference in failure rate by BMI (P = .26) or by malalignment (outside of 3° from neutral mechanical axis) (P = .67). Age was associated with failure as patients with failed TKAs were younger (61 vs 65, P < .01). CONCLUSION: This design of a specific modular titanium base plate with a cruciate-shaped keel and grit blast surface demonstrated 99% survivorship regardless of patient BMI or malalignment over 7-year follow-up period. Consistent cement technique with high viscosity cement indicates that component design remains an important variable impacting survivorship in TKA.
