In metal-on-metal (MoM) hip replacements or resurfacings, mechanical induced corrosion can lead to a local inflammatory response, pseudo tumours and elevated serum metal ions, requiring revision surgery.

The size and diametral clearance of Anatomic (ADM) and Modular (MDM) Dual Mobility bearings matches that of certain MOM components. Presenting the opportunity for revision with exchange of the metal head for ADM/MDM bearings without removal of the acetabular component if it is well-fixed and appropriately positioned.

Between 2012 and 2020, across two centres, 94 patients underwent revision of a MoM hip replacement or resurfacing. The mean age was 65.5 (33–87) years. In 53 patients (56.4%), the acetabular component was retained, and dual mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). DM was only considered where the acetabular component was satisfactorily positioned and well-integrated into bone, with no surface damage. Patients underwent clinical and radiographic follow-up to at least one-year (mean 42.4 (12–96) months).

One (1.1%) patient died before one-year, for reasons unrelated to the surgery. In the DM group, two (3.8%) patients underwent further surgery; one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (12.2%) underwent further procedures; two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operative time (68.4 v 101.5 mins, p<0.001), postoperative drop in haemoglobin (16.6 v 27.8 g/L, p<0.001), and length of stay (1.8 v 2.4 days, p<0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p<0.001 both Cobalt and Chromium) although there was no difference between groups for this reduction (p=0.674 Cobalt; p=0.186 Chromium).

In selected patients with MoM hip arthroplasty, where the acetabular component is well-fixed, in a satisfactory position and there is no surface damage, the metal head can be exchanged for ADM/MDM bearings with retention of the acetabular prosthesis. Presenting significant benefits through a less invasive procedure, and a low risk of complications, including dislocation.

The MAKO Robotic arm is a haptic robotic system that can be used to optimise performance during total hip arthroplasty (THA). We present the outcome of the first 40 robotic cases performed in an NHS foundation trust along with the technique of performing robotic THA in our unit.

Forty consecutive patients undergoing robotic THA (rTHA) were compared to a case matched group of patients undergoing manual THA (m-THA). 2:1 blinded case matching was performed for age, sex, implants used (Trident uncemented socket and cemented Exeter stem, Stryker Mahwah, NJ, US) and surgeon grade. Comparisons were made for radiological positioning of implants, including leg length assessment, and patient reported functional outcome (PROMS). Pre- and post-operative radiographs were independently analysed by 2 authors.

All patients underwent THA for a primary diagnosis of osteoarthritis. No significant difference between groups was identified for post-operative leg length discrepancy (LLD) although pre-operatively a significantly higher LLD was highlighted on the MAKO group, likely due to patient selection. Significantly lower post-operative socket version was identified in the MAKO cohort although no difference in post-operative cup inclination was noted. However, there was significantly larger variance in post-op LLD (p=0.024), cup version (p=0.004) and inclination (p=0.05) between groups indicating r-THA was significantly less variable (Levene's test for homogeneity of variance). There was no significant difference in the number of cases outside of Lewinnek's ‘safe’ zone for inclination (p=0.469), however, there were significantly more cases outside Lewinnek's ‘safe’ zone for version (12.5% vs 40.3%, p=0.002) in the m-THA group.

We report the commencement of performance of MAKO robotic THA in an NHS institution. No problems with surgery were reported during our learning curve. Robotic THA cases had less variability in terms of implant positioning suggesting that the MAKO robot allows more accurate, less variable implant positioning with fewer outliers. Longer term follow-up of more cases is needed to identify whether this improved implant positioning has an effect on outcomes, but the initial results seem promising.

When Radiolucent lines (RLL) are observed around cemented acetabular components, they may progress and be associated with loosening.

We reviewed the incidence and progression of RLLs around the Exeter Contemporary flanged acetabular component and compared our results with other published series.

We reviewed a consecutive series of 203 sockets with a minimum 10-year follow-up. Up to date radiographs were reviewed by 2 independent assessors for the presence, location and thickness of RLL and an assessment for loosening/migration was made. Initial post-operative radiographs were examined for any case with RLLs at review.

There were no revisions for aseptic loosening. 103 hips remained in situ with a minimum follow up of 10 years. Lucent lines were seen on 37/103 (36%) of hips with a mean follow up of 12.1 years (10.0–13.9 years). In these 37 hips, the lucency was present in one zone in 84%, two zones in 8% and all three zones in 8%.

Of the 37 hips with a RLL at minimum 10 years follow up, five exhibited a RLL immediately post-operatively. All 5 of these lines were initially isolated to zone 1 and progressed over the 10 years around at least 1 more zone. Only one line became circumferential, although the cup did not migrate.

Compared to previous papers (DeLee & Charnley, Hodgkinson and Garcia-Cimbrelo) the presence of RLL at 10 years is reduced in our series (table 2) and no cup migrated. All RLL seen in cups at both 10 years and immediate post-operatively in our series progressed (table 3), unlike in the previous studies. This reduction in lucent lines may be down to modern cementing techniques, cup design or a combination of both.

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Introduction

Reoperation within thirty days after hip fracture surgery is associated with increased mortality, length of stay and cost of care. The United Kingdom National Hip Fracture Database (NHFD) reported a significant increase in the 30-day reoperation rate for patients undergoing surgery for hip fractures in our unit from 2012 to 2014. We audited our data in order to validate this and identify any reversible trends.

Aims

We report on the outcome of the Exeter Contemporary flanged cemented all-polyethylene acetabular component with a mean follow-up of 12 years (10 to 13.9). This study reviewed 203 hips in 194 patients. 129 hips in 122 patients are still in situ; 66 hips in 64 patients were in patients who died before ten years, and eight hips (eight patients) were revised. Clinical outcome scores were available for 108 hips (104 patients) and radiographs for 103 hips (100 patients).

Introduction

We report on the outcome of a cemented flanged acetabular component at a minimum of 10 years post-operatively.

The technique of femoral cement-in-cement revision is well established, but there are no previous series reporting its use on the acetabular side at the time of revision total hip replacement. We describe the technique and report the outcome of 60 consecutive acetabular cement-in-cement revisions in 59 patients at a mean follow-up of 8.5 years (5 to 12). All had a radiologically and clinically well-fixed acetabular cement mantle at the time of revision. During the follow-up 29 patients died, but no hips were lost to follow-up. The two most common indications for acetabular revision were recurrent dislocation (46, 77%) and to complement femoral revision (12, 20%).

Of the 60 hips, there were two cases of aseptic loosening of the acetabular component (3.3%) requiring re-revision. No other hip was clinically or radiologically loose (96.7%) at the latest follow-up. One hip was re-revised for infection, four for recurrent dislocation and one for disarticulation of a constrained component. At five years the Kaplan-Meier survival rate was 100% for aseptic loosening and 92.2% (95% CI 84.8 to 99.6), with revision for any cause as the endpoint.

These results support the use of cement-in-cement revision on the acetabular side in appropriate cases. Theoretical advantages include preservation of bone stock, reduced operating time, reduced risk of complications and durable fixation.

Comparison of the safety and efficacy of bilateral simultaneous total hip replacement (THR) and that of staged bilateral THR and unilateral THR was conducted using DerSimonian-Laird heterogeneity meta-analysis. A review of the English-language literature identified 23 citations eligible for inclusion. A total of 2063 bilateral simultaneous THR patients were identified. Meta-analysis of homogeneous data revealed no statistically significant differences in the rates of thromboembolic events (p = 0.268 and p = 0.365) and dislocation (p = 0.877) when comparing staged or unilateral with bilateral simultaneous THR procedures. A systematic analysis of heterogeneous data demonstrated that the mean length of hospital stay was shorter after bilateral simultaneous THR. Higher blood transfusion requirements were expected following bilateral simultaneous THR than staged or unilateral THR, and surgical time was not different between groups. This procedure was also found to be economically and functionally efficacious when performed by experienced surgeons in specialist centres.