Is Modular Dual Mobility Superior to Standard Bearings for Reducing Dislocation Risk after Primary Total Hip Arthroplasty? A Retrospective Comparative Multicenter Study.

BACKGROUND: Dual mobility (DM) has been proven to reduce dislocation risk after total hip arthroplasty (THA). In the last decade modular DM (modDM) constructs have been introduced to allow the use of DM articulation with standard cementless acetabular shells. However, clinical evidence of modDM effectiveness is still low in primary THA and concerns about implant-related complications are increasing. This retrospective comparative multicenter study is aimed to investigate if the dislocation rate after primary THA could be reduced with modDM in comparison to standard bearing (SB). METHODS: 262 THAs were performed between 2017 and 2019, using SB (129 hips) or modDM (133) with the same cementless highly porous modular acetabular cup. Dislocations, complications and revisions were recorded and implant survival was analyzed. RESULTS: At 2.5-year mean follow-up, dislocation occurred in 4 hips (3.1%) within the SB group while intraprosthetic dislocation in 2 hips (1.5%) within the modDM group (p = 0.44). Implant survivals with revision due to dislocation were 95.2% and 95.9% at 4-year follow-up for SB and modDM, respectively (p = 0.50). CONCLUSIONS: modDM used in primary THA might reduce dislocation rate in comparison to SB, even in high-risk patients, however, caution is advocated due to specific intraprosthetic dislocation.

The management of Vancouver B1 and C periprosthetic fractures: radiographic and clinic outcomes of a monocentric consecutive series.

INTRODUCTION: Periprosthetic fractures (PFs) are a main complication after total hip arthroplasty (THA), with rising incidence. The optimal treatment of PFs is still being debated in the literature. Historically, high failure and reoperation rates are reported, although the introduction of locking plates has led to improved results. In this study we report clinical and radiographic outcomes of a consecutive series of Vancouver B1 and C fractures, treated with a novel type of locking plate. We also aim to identify the variables associated with healing time. METHODS: Between June 2013 and May 2019, 47 patients were consecutively admitted to the Emergency Department of our Hospital with a diagnosis of PF around a well-fixed THA stem. 31 patients fulfilled the inclusion criteria and were included in the study. All patients underwent osteosynthesis with a novel type of plate ("Ironlady" Intrauma, Rivoli, Italy) through a distally extended posterolateral approach. All surgical procedures were performed with the aim of reducing the rigidity of the fixation construct and preserving periosteal vitality. Demographic data, type of fracture, type of stem and its fixation, surgical details, and clinical and radiographical outcomes were recorded. Each variable was investigated to assess its relationship with fracture healing and healing time. RESULTS: 31 patients were included in the study. 4 patients died before the minimum follow-up of 6 months and were excluded from the series. The final sample consisted of 27 patients. Their median age at operation was 84.8 years (range 65.3-95.4 years); 21 were female. The median follow-up after surgery was 2.36 years (range 6 months-4.7 years). In the cohort there were 22 type Vancouver B1 fractures (81.5%) and 5 type C (18.5%). All fractures occurred postoperatively (no acute intraoperative fractures). Fracture union was achieved in 26 patients (96.3%). The following variables were found to be associated with increased healing time: Vancouver type of fracture, pattern of Vancouver B1 fracture type, age and male gender. CONCLUSIONS: On the base of our results, the management of Vancouver B1 and C type of PFs by locking plate osteosynthesis appears to be a safe and effective procedure. To enhance healing and reduce complication rate, accurate surgical technique is required, aiming to implement the proximal fixation, avoid stress rising, reduce rigidity of the osteosynthesis construct and preserve the plate-to-bone gap.

MODULUS Stem for Developmental Hip Dysplasia: Long-term Follow-up.

Between October 2001 and December 2010, 143 patients with developmental dysplasia underwent hip arthroplasty surgery using a conical stem with modular necks (MODULUS system, Lima Corporate, Villanova di San Daniele del Friuli, Italy). Thirty (21.0%) patients had both hips replaced, for a total of 173 implants. The mean age at the time of surgery was 55 years (range: 22-81 years). The mean follow-up was 87 months (range: 36-146 months); average Harris Hip Score increased from 42 (range: 23-65) preoperatively to 92 (range: 76-100) at the last follow-up. Stem revision was required in two cases. The MODULUS stem showed good long-term clinical and radiographic results, with a Kaplan-Meier survivorship of 97.6% (95% CI: 94.8-100.0%) at 8 years.

Mid-term results of an uncemented femoral stem with modular neck options.

We prospectively assessed the results of 239 primary total hip replacements performed using a conical stem combined with modular necks of different lengths and inclinations (Modulus System, Lima Corporate San Daniele Del Friuli, Udine, Italia) in 222 patients (50 men, 172 women), undergoing surgery between October 2001 and December 2006 and presenting with anatomical deformities of the proximal femur and/or acetabulum, including developmental dysplasia (DDH), ankylosis, and sequelae of osteotomies or fractures. Such conditions can make hip replacement problematic. The mean age at the time of surgery was 57.6 years (22 ÷ 83). No patients were lost to follow-up. 3 femoral components underwent revision. At a mean of 5 years follow-up the Harris Hip Score showed a significant improvement, increasing from 35 preoperatively to a mean of 96.6. Using Kaplan-Meier analysis the survival rate at 5 years was 98.28%. The Modulus stem showed good mid-term results in terms of survival, as well as clinical and radiographic outcome.