Acetabular revision using a dual mobility cup as treatment for dislocation in Charnley total hip arthroplasty

Post-operative complications following total hip arthroplasty for trauma: A multicentre cohort study comparing dual mobility with conventional acetabular bearings

Aims

Dislocation of a total hip replacement is a serious complication after total hip arthroplasty (THA). Dislocation rates are higher when surgery is performed following trauma. Our study compares post-operative dislocation rates between conventional acetabular bearing (CAB) and dual mobility acetabular bearing (DMB) THA performed for neck of femur fracture alongside post-operative periprosthetic fracture, revision and mortality.

Methods

A retrospective multicentre cohort study at 9 hospital trusts in the United Kingdom of all THA performed for neck of femur fracture between March 2018 and February 2019.

Results

A total of 295 operations were performed. 64% (189) were CAB and 36% (106) were DMB. Average age was 75 years (38-98). 223 Female: 72 Male. The follow-up period was an average of 42 months (36-48). Overall revision rate was 1.6%,8 peri-prosthetic fracture rate was 6 (2%) and overall mortality was 9.8% (29) with no significant difference between cohorts for any outcome. The posterior approach (PA) was favoured 82% (242) vs the lateral approach (LA) 18% (53) with the PA used more often in patients undergoing DMB 96% (102) vs CAB 74% (140) p = 0.001. Patients approached posteriorly at the time of their index procedure were significantly less likely to sustain a simple dislocation following a DMB 0 (0%) vs. CAB 8 (5.7%) p = 0.015.

Conclusion

Our study demonstrates that the risk of dislocation following THA for trauma is more than four times higher than when conventional bearings are used compared to dual mobility acetabular components. This effect is most pronounced when the PA is utilised for the index procedure. The use of these bearings does not impact mortality, peri-prosthetic fracture or revision rate. We would encourage the use of dual mobility acetabular bearings in patients undergoing THA for fracture via a PA.

Acetabular Lip Augmentation Devices for the Unstable Total Hip Replacement-A Systematic Review

Background

The optimal management strategy for instability afte total hip arthroplasty remains unclear. Acetabular lip augmentation devices may offer an operative solution for recurrent instability. This systematic review reports the clinical outcomes of acetabular lip augmentation devices in comparison to other treatment options.

Methods

A literature search strategy was performed of Medline, EMBASE, and CENTRAL on September 19, 2020, for all studies reporting outcomes of acetabular lip augmentation devices for recurrent dislocation after total hip arthroplasty. Non-English language articles were excluded. Clinical and survivorship data were collated and analyzed.

Results

Thirteen studies describing acetabular augmentation were included for analysis. A total of 644 hips in 636 patients were augmented with a mean age of 75 years (39 to 103). Five different augmentation devices were used. The posterior lip augmentation device (PLAD, DePuy) was the most used (406 hips). Overall, acetabular lip augmentation devices had a 10% postoperative dislocation rate at a mean follow-up of 49 months (0.2 to 132). The PLAD had a 3.9% subsequent dislocation rate with a mean follow-up of 51 months (0.2 to 132). Only one study compared the PLAD to a dual-mobility cup, which demonstrated shorter operative times with the PLAD but higher rates of dislocation and revision surgery.

Conclusion

The quality of literature on lip acetabular augmentation devices is poor. In these studies, the postoperative dislocation rate after lip acetabular augmentation was relatively high. The PLAD (DePuy) has the most evidence and may offer a therapeutic option for recurrent instability, in very specific clinical situations.

Risk factors and modes of failure in the modern dual mobility implant. A systematic review and meta-analysis

Background

The aims of this meta-analysis were to: (1) validate the outcome of modern dual mobility (DM) designs in patients who had undergone primary and revision total hip arthroplasty (THA) procedures and (2) to identify factors that affect the outcome.

Methods

We searched for studies that assessed the outcome of modern DM-THA in primary and revision procedures that were conducted between January, 2000 to August, 2020 on PubMed, MEDLINE, Cochrane Reviews and Embase. The pooled incidence of the most common failure modes and patient reported outcomes were evaluated in patients who have received: (1) primary THA, (2) revision THA for all causes or (3) for recurrent dislocation. A meta-regression analysis was performed for each parameter to determine the association with the outcome. The study design of each study was assessed for potential bias and flaws by using the quality assessment tool for case series studies.

Results

A total of 119 studies (N= 30016 DM-THAs) were included for analysis. The mean follow-up duration was 47.3 months. The overall implant failure rate was 4.2% (primary: 2.3%, revision for all causes: 5.5%, recurrent dislocation: 6.0%). The most common failure modes were aseptic loosening (primary: 0.9%, revision for all causes: 2.2%, recurrent dislocation: 2.4%), septic loosening (primary:0.8%, revision for all causes: 2.3%, recurrent dislocation: 2.5%), extra-articular dislocation (primary:0.6%, revision for all causes:1.3%, recurrent dislocation:2.5%), intra-prosthetic dislocation (primary:0.8%, revision for all causes:1.0%, recurrent dislocation:1.6%) and periprosthetic fracture (primary:0.9%, revision for all causes:0.9%, recurrent dislocation:1.3%). The multi-regression analysis identified younger age (β=-0.04, 95% CI -0.07 – -0.02) and female patients (β=3.34, 95% CI 0.91–5.78) were correlated with higher implant failure rate. Age, gender, posterolateral approach and body mass index (BMI) were not risk factors for extra-articular or intra-prosthetic dislocation in this cohort. The overall Harris hip score and Merle d’Aubigné score were 84.87 and 16.36, respectively. Level of evidence of this meta-analysis was IV.

Conclusion

Modern dual-mobility designs provide satisfactory mid-term implant survival and clinical performance. Younger age and female patients might impact the outcome after DM-THA. Future research directions should focus on, (1) long-term outcome of modern dual-mobility design, including specific concerns such as intra-prosthetic dislocation and elevated metal ion, and (2) cost-effectiveness analysis of dual-mobility implant as an alternative to conventional THA for patients who are at high risk of dislocation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04404-4.