Mid-term results of total hip arthroplasty with anatomical ultra-short cementless stem in patients with developmental dysplasia of the hip Crowe type II.

The aim of this study was to present the mid-term results of ultra-short cementless stem total hip arthroplasty (THA) in patients with Crowe type II developmental dysplasia of the hip. The study consists of 68 patients (75 THAs) with a Proxima stem implanted between 2006 and 2015. The clinical results include Harris Hip Scores. Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. Kaplan-Meier survival analysis was performed. The mean age of patients was 48.4 years, with a mean follow-up 114 months. The average Harris Hip Score improved significantly from 45.1 preoperatively to 97.6 at the final evaluation (p < 0.001). Stem migration was observed in five hips (in all of them up to the 6th postoperative month, without any further progression of migration or radiological loosening). Bony trabecular development was detected in modified Gruen zones (1, 2, 4, 6, 7 for Proxima stem): in zone 1 (0%), 2 (49.3.0%), 4 (38.7%), 6 (82.7%), 7 (0%). Radiolucent lines were observed around one cup (DeLee and Charnley zone I) and three stems (none was loose, all three with fibrous stable fixation). Complications were found in three hips (4.0%): intraoperative periprosthetic femoral fracture (threated with cerclage wire) in two hips and squeezing hip in one patient (with perioperative ceramic inlay breakage and exchange). No hip was revised. The implant survival was 100.0% both clinically and radiologically. Observations in the mean follow-up of 114 months show that the results (clinical and radiological) of the Proxima stem in patients with Crowe type II DDH are promising.

Dynamic hip screw in proximal femoral fractures followed by "single-stage" hip arthroplasty-retrospective analysis.

The aim of this study is to present the results of single-stage total hip arthroplasty (THA) after Dynamic Hip Screw (DHS) failure, or secondary posttraumatic osteoarthrosis. From 2003 to 2020, 15 THAs were performed in group of 15 patients for the treatment of DHS failure, or for late complications following femoral neck and pertrochanteric fractures. The mean follow-up period after arthroplasty was 46.9 months (range 7-139). The patients were evaluated retrospectively-both clinically and radiographically, focussing on the demography, infection rate and other complications (revision surgery), during the year 2023. 9 males and 6 females were included in the study, with a mean age of 56.5 years (range 29-93) at the time of primary osteosynthesis. Each of them had proximal femoral fracture treated primarily with a DHS and then late one-stage revision surgery, with hardware removal and THA implantation. The median time between DHS osteosynthesis and THA was 41.2 months (range 4-114). Four patients (26.6%) had complications after THA, with the need for revision in two cases (13.3%). Dislocation rate was 6.6% (one case), with the need for repeated-revision of THA. The infection rate was 6.6% (one patient) with the need for revision of THA. Peroperative periprosthetic femoral fracture was observed in 13.3% (two patients) without any other problems. Six patients (40%) died during the follow-up period. Single-stage total hip arthroplasty with concomitant hardware removal bears a high- mortality rate, with a higher incidence of postoperative complications compared to elective THA.

Total hip arthroplasty with ultra-short uncemented stem in patients with osteonecrosis of the femoral head: mid-term results.

BACKGROUND: Mid-term results (clinical and radiographic) of ultra-short anatomical cementless stem total hip arthroplasty (THA) in patients with osteonecrosis of the femoral head (ONFH) has not often been presented. The aim of this study is to evaluate THA using the Proxima stem in patients with ONFH in the mid-term. METHODS: The study consists of 73 patients (97 THAs) with a Proxima stem implanted between 2006 and 2015. The mean age of patients was 47.4 years, with a mean follow-up 105.2 months. The clinical results include preoperative and postoperative Harris Hip Scores (HHSs). Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. The complications and revisions were registered. Kaplan-Meier survival analysis was performed to determine the implant survival. RESULTS: The average HHS improved significantly from 40.3 preoperatively to 98.0 at the final evaluation (p ˂ 0.0001). Stem migration (subsidence and "varisation") was observed in 11 hips (in 9 of them up to 6th postoperative month without any further progression, in 2 with progressive migration and radiological loosening). Bony trabecular development was detected in modified Gruen zones (1,2,4,6,7 for Proxima stem): in zone 1 (0%), 2 (67.0%), 4 (64.9%), 6 (64.9%), 7 (0%). Radiolucent lines were observed in 1 cup and 6 stems (2 were loose, 4 with fibrous stable fixation). Complications were found in 5 hips (5.1%): squeezing hip once, repeated dislocation in 1, 1 early deep infection, and 2 loose stems. 2 hips (2.1%) were revised (dislocation, infection). The implant survival was 98.9% and 97.9% clinically and radiologically, respectively. CONCLUSIONS: Observations in the mid-term show that the clinical and radiological results of the Proxima stem in patients with ONFH are promising. The stem design preserves the proximal femoral bone stock. The bony trabecular appearance confirms physiological proximal femoral load transmission.