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.

For any figures or tables, please contact the authors directly by clicking on ‘Info & Metrics’ above to access author contact details.

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 management of patients with displaced intra-capsular hip fractures is usually a hip hemiarthoplasty procedure. NICE guideline 124 published in 2011 suggested that Total Hip Replacement (THR) surgery should be considered in a sub group of patients with no cognitive impairment, who walk independently and are medically fit for a major surgical procedure.

The Royal Devon and Exeter Hospital manages approximately 550 patients every year who have sustained a fracture of neck of femur, of which approximately 90 patients fit the above criteria. Prior to the guideline less than 20% of this sub-group were treated with a THR whereas after the guideline over 50% of patients were treated with THR, performed by sub-specialist Hip surgeons.

This practice is financially viable; there is no apparent difference in the overall cost of treating patients with THR. The effect of adoption of the NICE guideline was examined using 100 % complete data from 12 month post operative follow up. Only the Hemi-arthroplasty patients were significantly less likely to have stepped down a rung of independent living. Both THR and Hemi-arthroplasty patients were significantly less likely to have stepped down a rung of walking ability, but there was no significant difference between THR and Hemi-arthroplasty groups. Revision rates remained negligible.

The management of patients with displaced intra-capsular hip fractures is usually a hip hemiarthoplasty procedure. NICE guideline 124 published in 2011 suggested that Total Hip Replacement (THR) surgery should be considered in a sub group of patients with no cognitive impairment, who walk independently and are medically fit for a major surgical procedure.

The Royal Devon and Exeter Hospital manages approximately 600 patients every year who have sustained a fracture of neck of femur, of which approximately 90 patients fit the above criteria. Prior to the guideline less than 20% of this sub-group were treated with a THR whereas after the guideline over 50% of patients were treated with THR, performed by sub-specialist Hip surgeons. This change was achieved by active leadership, incorporation of ‘Firebreak’ lists, looking for cases, flexible use of theatre time and operating lists and the nomination of an individual senior doctor who was tasked with a mission to improve practice.

This practice is financially viable; the Trust makes over £1000 per THR for fracture. Complete outcome data at 120 days show significantly fewer patients stepping down a rung in terms of both independent living and independent walking.

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.

Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH. The objective was to perform a prospective evaluation of SDTSO with Cemented Exeter Femoral Component.

15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years were followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient was lost to follow-up.

Charnley-d'Aubigné-Postel scores for pain, function and range of movement were improved from a mean of 2, 2, 3 to 5, 4, 5 respectively. One osteotomy failed to unite at 14 months and was revised successfully. Clinical healing was achieved at a mean of 6 months and radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. A 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting was performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow-up. No sciatic nerve palsy was observed and no dislocation.

Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedullary autografting prevents cement interposition at the osteotomy site.

Comparison of the safety and efficacy of Bilateral Simultaneous Total Hip Arthroplasty (BSTHA) with that of staged (SgTHA) and unilateral (UTHA) 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 homogenous data revealed that there were no statistically significant differences between 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 heterogenous data demonstrated that mean length of hospital stay was shorter after bilateral simultaneous THR. Blood loss was reduced after bilateral simultaneous THR in all studies except for one, 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.

Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 Developmental Dysplasia of the Hip (DDH). Prospective evaluation of the use of subtrochanteric derotational femoral shortening with a cemented Exeter stem.

15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years followed-up for a mean of 114 months (range 52 to 168). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient lost to follow up. All 18 Crowe IV hips reviewed. Charnley-D’Aubigne-Postel score for pain, function and range of movement were improved from a mean of 2-2-3 to 5-4-5 respectively. One osteotomy failed to unite at 14 months and revised successfully. Clinical healing was achieved at a mean of 6 months while radiological evidence of union at a mean of 9 months. The mean length of the excised segment was 3 cm and the mean true limb lengthening was 2 cm. 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting performed in all cases. Mean subsidence was 1 mm and no stem was found to be loose at the latest follow up. No sciatic nerve palsy was observed and there were no post-operative dislocations.

Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with when a subtrochanteric derotational shortening osteotomy (SDSO) was necessary. A transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedullary autografting prevents cement interposition at the osteotomy site and promotes healing.

There is evidence that recommends the retention of a well-fixed cement mantle at the time of revision hip arthroplasty. The cement-cement interface has been proven to have greater shear strength than a new bone-cement interface after removing a well-fixed cement mantle. This study reviewed a series of acetabular revision procedures with a minimum 2-year follow-up where the original cement mantle was left intact. From 1988 to 2004, 60 consecutive cement-in-cement revisions of the acetabular component were performed at our institution. Outcome was based on functional assessment using the Oxford, Charnley, and Harris scoring systems as well as radiographic analysis using the DeLee and Charnley criteria.

In total 60 procedures were performed in 60 patients (40 female and 20 male), whose mean age at surgery was 75 years (range 40 to 99 years). 80% were performed for recurrent dislocation, 13.3% during femoral component revision, 5% for acetabular component wear, and 1.7% for pain. No case was lost to follow-up.

There was one re-revision for aseptic cup loosening at 7 years, with 1 further case of radiological loosening identified at the latest review. There were 6 further cases of dislocation 4 of which were treated with further in-cement revisions. All other cases showed well-fixed components on radiographic analysis and no evidence of failure at the most recent follow up.

The cement-in-cement technique already has a good body of evidence based on revision of the femoral component and this study shows that the technique can be applied to acetabular revisions as well with good functional and radiological results in the short to medium term.

There is evidence that recommends the retention of a well-fixed cement mantle at the time of revision hip arthroplasty. The cement-cement interface has been proven to have a greater shear strength than a new bone-cement interface after removing the old cement mantle.

This study reviewed a series of acetabular revision procedures with a minimum 2 year follow-up where the original cement mantle was left intact. From 1988 to 2004, 61 consecutive cement-in-cement revisions of the acetabular component were performed at our institution. Outcome was based on functional assessment using the Oxford, Charnley, and Harris scoring systems as well as radiographic analysis using the DeLee and Charnley criteria.

In total 61 procedures were performed in 59 patients (40 female and 19 male), whose mean age at surgery was 75 years (range 40 to 99 years). 47 hips (77%) were performed for recurrent dislocation, 12 for polyethylene wear associated with other reasons for revision (aseptic stem loosening in 8, stem fracture in 2, femoral periprosthetic fracture in 1, subluxation in 1), 1 for unexplained pain, and 1 for disarticulation (intraprosthetic dislocation) of a constrained liner. No case was lost to follow-up. There was a significant improvement in the functional scores from the pre-operative status with the patients maintaining a low level of pain. There was one re-revision for aseptic cup loosening at 7 years, with 1 further case of radiological loosening identified at the latest review. There were 6 further cases of dislocation 4 of which were treated with further in-cement revisions. All other cases showed well-fixed components on radiographic analysis and no evidence of failure at the most recent follow up.

The cement-in-cement revision technique can be used in selected cases of acetabular revision surgery, providing satisfactory functional outcomes backed up by good radiographic results. Blood loss and surgical time are also significantly decreased.

Objectives: Retrospective case control study of management and outcome of periprosthetic femoral fractures, from the lower limb reconstruction unit in Exeter.

Material and Methods: 144 fractures over a period of 20 years were reviewed. The Vancouver classification system wasd used to clasify the fractures. The prosthesis length was measured pre and post-peratively. The use of impaction grafting technique for inadequate bone quality of the surrounding bone was assessed (type B3 fractures). The use of Dall/Miles, DCP and Mennen plates was also assessed. Healing was defined using radiological and clinical criteria and where available the Harris Hip Score. Chi-square test with p< 0.05 was used for the statistical analysis of the Results:

Results: When the Vancouver system was applied 2.85% of the fractures were classified as type A, 87.2% as type B and 10% as type C. Within the type B group 13.2% were subtype B1, 12% subtype B2 and 62% subtype B3. 1 out of 6 Mennen, 4 out of 16 Dall/Miles and 2 out of 20 DCP plates failed. Overall 68% healing, 5% non-union, 4% infection, 23% re-fracture rate at 12 months follow-up. Better healing was achieved when impaction grafting was used for B3 fractures (p=0.001). Better healing was achieved when the revision stem was bypassing the most distal fracture line by at least 2 ipsilateral femoral diameters and impaction grafting was used for B3 fractuires (p=0.01).

Conclusion: Impaction Grafting can compensate for the inadequate bone in type B3 fractures and appears to promote union. Revision stem should bypass the most distal fracture line by at least 2 cortical diameters to achieve healing.

Introduction: Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH.

Objective: Prospective evaluation of SDTSO with Cemented Exeter Femoral Component.

Material and Methods: 15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient lost to follow up.

Results: 18 Crowe IV hips. Charnley-D’Aubigne-Postel score for pain, function and range of movement were improved from a mean of 2, 2,3 to 5,4,5 respectively. One osteotomy failed to unite at 14 months and revised successfully. Clinical healing was achieved at a mean of 6 month while radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow up. No sciatic nerve palsy observed and no dislocation.

Conclusion: Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedulary autografting prevents cement interposition at the osteotomy site.

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.

Introduction: Concerns have been raised regarding both the risk of non-union, and the ability to achieve stability with the use of an ETO in combination with cemented femoral impaction allografting.

Objective: To evaluate the long term follow-up results on all patients using ETO with Impaction Grafting.

Material and Methods: Eighteen patients with a mean age of 61 years were prospectively evaluated. The mean follow-up was 60 months (13 – 114). Charnley-D’aubigne-Postel scores, stem length, ETO length, ETO healing and complications were recorded. No patient was lost to follow-up.

Results: In 13 cases the femur was classified as Paprosky type 3B, in 1 case type 3A and in 4 cases type 4. The mean femoral diameter was 25 mm and the mean osteotomy length was 130 mm. In all cases the stem bypassed the distal osteotomy site with a mean of 58 mm (mean ratio to femoral diameter 2.3). Radiological and clinical healing were achieved in all cases at a mean of 6 months. No evidence of graft-host subsidence or lack of femoral stability was observed.

Conclusion: Further to bone augmentation, Impaction Grafting when performed appropriately protects the osteotomy site from cement interposition leading to a secure bony union of the osteotomy site. The distal osteotomy site should be bypassed by at least 2 ipsilateral femoral diameters. The presence of an ETO did not appear to affect graft stability.

Impaction bone grafting with a cemented polished double-taper stem as a technique for revision of the femoral component was introduced in 1987 at our institution.

As at January 2000, 540 cases in 487 patients had been performed. All procedures have been studied prospectively and there are no patients lost to follow-up. We present the survivorship and outcome data for these patients.

Survivorship at 15 years is 90.6 percent [95 percent confidence interval: 88–93 percent]. Clinical scores show marked and sustained improvement.

There have been 45 failures [8.3 percent]. Technical error contributed to 13 of the 24 non-infective complications, but with improved technique plus the addition of long stemmed impaction grafting, there have been no technical errors since 1996.

Our results show that revision of the femoral component with impaction bone grafting is a reliable and durable technique with an acceptably low complication rate and with excellent survivorship at 15 years.

Introduction & Aims: To study the survivorship and subsidence patterns of the first 433 Exeter polished, totally collarless, double tapered, cemented stems that were inserted between November of 1970 and the end of 1975 by 16 different surgeons (13 of them in the training grades) utilising first generation cementing techniques.

Method: A survivorship study up to the 33rd year of follow-up, using the contingency table method, was performed for all 433 hips, the end-point being revision for aseptic stem loosening. Stem subsidence in relation to the cement and the bone was measured in all survivors by a single observer on digitised films (magnified 200%) using the Orthochart™ software. Stem subsidence, the grade of cementing, ‘calcar’ resorption, visible cement fractures, focal lysis and radiolucent lines at the interfaces were assessed.

Results: Of the 433 hips, 21 were revisions of previously failed hips. 21.7% of patients have had a re-operation of some sort including 3.69% for stem fracture, 3.46% for neck fracture (all from a group of 95 stems with excessively machined necks), 9% for aseptic cup loosening, 3.46% for aseptic stem loosening, 1.84% for infection and 0.23% for recurrent dislocation). For the overall series, with revision for aseptic stem loosening as the end-point, the survivorship is 91.42% (95%CI: 70.82 to 100%). When all cases lost to follow-up (28 hips) are regarded as failures, survivorship is 82.9% (95%CI: 58.37 to 100%).

The average age at operation of the survivors was 55.7 years. No significant radiological subsidence between the cement and bone was found. Mean subsidence between the stem and the cement was 2.15mm, most occurring in the first 5 years and in all but 1 being less than 4. The maximum was 18mm (grade D cementing). Cementing grades were B in 65%, C in 27%, D in 8%. Resorption of the neck (13%) was associated with excessive socket wear or cement left over the cut surface of the neck (the ‘pseudocollar’). Visible cement fractures were found in 14%, none associated with focal lysis, which was seen in 11%.

Conclusions: Although 21.7% of patients in this series of the first 433 Exeter hips to be inserted in Exeter needed a re-operation of some sort, the stem rarely required surgery for aseptic loosening and was associated with benign long-term X-Ray appearances in spite of 1st generation cementing.