The use of dual mobility cups in revision total hip arthroplasty for failed large head metal-on-metal bearings.

PURPOSE: Revision of failed large head metal-on-metal (MoM) total hip arthroplasty (THA) is a challenging procedure particularly to reconstruct acetabular bone defect due to osteolysis and to achieve hip stability due to soft tissue damages, both potentially caused by adverse reaction to metal debris (ARMD). This study aimed to evaluate the outcome of dual mobility cup (DMC) constructs in revision THA for failed large head MoM bearings with a special attention to the occurrence of dislocation or re-revision. METHODS: Between 2015 and 2019, 57 patients (64 THAs, 41 men, mean age = 65 ± 10 years) underwent revision for MoM THA with the use of DMC were prospectively included in our total joint registry. Mean time to revision was 11 ± 2.5 years. The causes for revision were adverse reaction to metal debris (ARMD) in 49 THAs (76%), painful hip with elevated blood cobalt-chromium ions in seven (11%), and acetabular aseptic loosening in eight (13%). The revision was complete in 22 THAs (34%) and acetabular only in 42 (66%). Clinical and radiographic outcomes, complications, and re-revisions were evaluated at most recent follow-up. RESULTS: At mean follow-up of six ± 1.5 years, the pre- to postoperative Harris Hip Score improved from 74 ± 19 to 92 ± 4 (p = 0.004). Complications occurred in 11 cases (17%): five dislocations (8%), three periprosthetic infections (5%), two aseptic loosening of the acetabular component (3%), and two periprosthetic fractures (3%). Re-revision was required in six cases (9%). CONCLUSION: The use of DMC is a reliable option to prevent instability and ensure a stable acetabular reconstruction in revision THA for failed large head MoM bearings. However, dislocation after revision remains a concern, particularly in cases of severe soft tissue damage related to ARMD.

Epidemiology of Pediatric Upper Extremity Fractures in a Tertiary Care Center in Switzerland.

OBJECTIVE: Fractures in children are common and account for 10% to 25% of injuries in children with considerable effects on activity restriction and subsequent high socioeconomically impact. Eighty percent of all fractures in children occur at the upper extremity. The article investigates the epidemiology and fracture pattern of the upper extremity within a pediatric population consulting a tertiary referral hospital in Switzerland. METHODS: Study population included all patients younger than 18 years presenting with an upper extremity fracture. Recorded data were age, sex, side, season of the year, mechanism, type of fracture, and applied treatment. RESULTS: Fractures of the upper extremities represented 76% with a mean age of 9 years and 7 months. Compared with girls, boys had a risk ratio of 1.35 (1.14-1.6) of having a traumatic injury. The radius, with 298 fractures (37%), was the most injured bone. Overall simple fall from his or her height and soccer represented the main injury mechanisms accounting for 26% and 9%, respectively. Eighty-six percent of fractures were treated by cast with or without closed reduction, 11% (92) by closed reduction and pinning or elastic stable intramedullary, and only 3% of fractures were treated by open reduction and internal fixation. CONCLUSIONS: Eighty-six percent of all fractures could be treated by conservative methods. Only 17% need surgical treatments by orthopedic surgeons. This shows how important it is to train residents in pediatrics for the treatment of upper limb fractures in children.