Biomechanical Study Concerning the Types of Resection in Arthrodesis of First Metatarsophalangeal Joint.

This work concerns a biomechanical study aiming to ascertain the optimal type of joint resection when performing a joint arthrodesis. A 3-dimensional digital model of the first metatarsophalangeal joint including the entire first metatarsal bone and proximal phalanx using CT scans of the forefoot was created. Using this computer model, 4 types of resections; ball-and-socket, flat-on-flat, wedge 90°, and wedge 100° were simulated. Parameters measured using this model were the force necessary to separate the 2 fused surfaces, the surface area of the resected surfaces and the shortening of the first ray. By measuring the reactive force necessary to separate the phalanx from the first metatarsal, the 90° wedge resection was found to be the most stable, with comparable results in the case of the 100° wedge resection. Wedge resections are also more favorable when comparing the shortening of the first ray. Wedge resections, though being more technically difficult to perform prove to be the most stable for metatarsophalangeal joint-1 arthrodesis using this model.

Results of 198 primary total hip arthroplasties using the Delta PF-FIT system with ceramic-on-ceramic articulating surfaces with average seven years follow up.

BACKGROUND: The lifetime implants is a key parameter that the surgeon should take into account at the time of the primary total hip arthroplasty (THA). The aim of this study was a clinical and radiographical evaluation of the Delta PF-FIT (LimaCorporate, Italy) THA system with ceramic-on-ceramic articulations. We have not found a clinical or radiographical assessment of this implant in available published literature. METHODS: A total of 197 (F = 94, M = 103) primary THAs were evaluated in 163 patients with a mean follow-up of 7.7 years (range 5.1-11.2 years (SD ± 1.5)) Harris hip Score (HHS) and the Western Ontario and McMaster Universities Arthritis index (WOMAC) were used for the clinical evaluation. The statistical evaluation was processed by standard statistical methods. The study was approved by Ethic Committee of the University Hospital Motol (Reference No. EK-73/19). RESULTS: The mean HHS score was found to be 97.59 points (61-100 range with a ± 5.13 SD, preoperative HSS was 51.21, range 28-73 with a ± 4,77 SD). 186 THAs were evaluated as excellent (90-100 points), 9 THAs rated as good (80-89 points), 1 THA was rated as fair (70-79) points and 1 THA rated as poor (less than 70 points). The mean WOMAC score was 97.38 points (65-100 range with a ± 5.18 SD, preoperative was 50,12, range 27-69 with a ± 4.85 SD). We documented an overall 99.49% Kaplan-Meier survival with a mean follow-up of 7.7 years with the FIT (LimaCorporate) stem revision and any component revision as the endpoint. With the Delta PF (LimaCorporate) cup revision as the endpoint, the survival was 100%. We have not found a previously published clinical or radiographical review of this THA system, the study shows a comparison with other THA implants. CONCLUSION: Evaluation of the Delta-PF-FIT (LimaCorporate, Italy) THA system with the use of ceramic-on-ceramic BIOLOX®Delta articulation surfaces shows very good outcomes.