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.

Venous thromboembolism (VTE) is a preventable cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Clinical Excellence (NICE) has altered their prophylaxis guidance in the setting of total hip arthroplasty (THA). The aim of this study was to present the VTE incidence in 8,890 patients who underwent total hip arthroplasty between January 1997 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis.

Analysis of prospective data collection from consecutive patients undergoing THA was performed with the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within 6 months of the index operation as the primary outcome measure. 90-day all-cause mortality of this cohort of patients was also analysed.

8890 patients were reviewed. This included 7235 primary, 224 complex primary and 1431 revision cases. The incidence of DVT was 0.64% after elective THA and the incidence of PE was 0.54%. There was no difference in the incidence between primary and revision cases. The 90-day all-cause mortality was 0.88%. Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to VTE.

Our results support the use of aspirin as an effective form of prophylaxis against VTE following THA. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other attractive advantages of using aspirin for VTE prophylaxis.

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.

The Exeter V40 femoral stem is the most implanted stem in the NJR for primary THA. In 2004, the 44/00/125 stem was released for use in “cement-in-cement” revision cases. It has however been used ‘off-label’ as a primary stem when, for example, patient anatomy requires a smaller stem with a 44mm offset. We aimed to investigate survival of this stem in comparison to others in the range when used in primary THAs recorded in the NJR.

Analyses were performed using a dataset based on that used for the 2020 NJR annual report. Our exposure was the stem; the outcome was all-cause construct revision. Crude analyses were performed using Kaplan-Meier and adjusted using Cox models. The 44/00/125 stem was directly compared to other stems in the Exeter range.

We analysed 330,732 primary THAs using the Exeter V40 stem comprising 34.5% of the 958,869 THAs with complete information from the start of the NJR to 31 December 2018. The 44/00/125 stem was implanted in 2,158 primary THAs with 67.5% in female patients and a mean age of 67.8. The 10-year revision estimate for the 44/00/125 stem was 4.9% (95%CI 3.6, 6.8) and in constructs using an Exeter V40 stem was 2.8% (95%CI 2.7, 2.8). Controlling for age, sex and ASA demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (HR 1.8 (95%CI 1.4, 2.3)).

Although the revision estimate is within the NICE 10-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the Exeter V40 range. Attempts to control for age, sex and ASA will not take into account confounding by indication i.e. patients with more complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured by this but should be aware of the observed increased revision estimate and use the stem according to its indications.

Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision necessitate removal of all bone cement from the femur. In our two institutions, we have been using a cement-in-cement technique, leaving the distal femoral cement in selected cases for septic hip revision surgery.

Between February 2010 and September 2019, 89 patients with prosthetic hip infection underwent first or single stage procedures leaving the distal femoral cement in situ and performing a cement-in-cement revision. The mean patient age was 72.0 years (24–92). The median time from the last arthroplasty procedure was 29.0 months (1–294).

81 patients underwent revision using a cemented Exeter stem, 7 patients received an articulating spacer, and one patient underwent excision arthroplasty with the distal cement left in situ. Patients received clinical and radiographic follow-up with a mean of 42.8 months (range 11.0–120.1 months). Oxford hip scores were collected from each institution's existing databases.

9 patients (10.1%) died within one year of surgery. No deaths were directly related to joint infection or the surgery. One patient was lost to follow up before one year.

Of the remainder, 7 patients (8.9%) required further procedures for infection and were therefore considered to be treatment failures. 6 patients (7.6%) underwent planned second stage procedures with no recurrence of infection. 7 patients (8.9%) had further surgery for non-infective reasons. The Kaplan-Meier estimate of infection free survival at one year was 93.7% (95% CI 88.4 to 99.0%).

No patients underwent revision for stem loosening. Oxford hip scores were available at over one year postoperatively for 51 patients with a mean score of 30.6, and a mean gain of 11.9.

In our combined cohort of patients, cement-in-cement revision had an infection eradication rate of 91.1%. Patient selection is crucial, and the procedure can only be performed when there is a well-fixed cement mantle. However, when strict criteria are followed, this technique offers potential significant benefits to surgeons performing this challenging surgery, and more importantly the patients undergoing them.

Total hip replacements (THRs) provide pain relief and improved function to thousands of patients suffering from end-stage osteoarthritis, every year. Over 800 different THR constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Given the 10-year cumulative mortality of patients under 55 years of age receiving THRs is only 5% and that a recent study suggests 25-year THR survival of 58%, we aim to produce revision estimates out to 30 years that may guide future long-term benchmarks.

The local database of the Princess Elizabeth Orthopaedic Centre (PEOC), Exeter, holds data on over 20,000 patients with nearly 30-years follow-up with contemporary prostheses. A previous study suggests that the results of this centre are generalisable if comparisons restricted to the same prostheses. Via flexible parametric survival analysis, we created an algorithm using this database, for revision of any part of the construct for any reason, controlling for age and gender. This algorithm was applied to 664,761 patients in the NJR who have undergone THR, producing a revision prediction for patients with the same prostheses as those used at this centre.

Using our algorithm, the 10-year predicted revision rate of THRs in the NJR was 2.2% (95% CI 1.8, 2.7) based on a 68-year-old female patient; well below the current NICE benchmark. Our predictions were validated by comparison to the maximum observed survival in the NJR (14.2 years) using restricted mean survival time (P=0.32). Our predicted cumulative revision estimate after 30 years is 6.5% (95% CI 4.5, 9.4). The low observed and predicted revision rate with the prosthesis combinations studied, suggest current benchmarks may be lowered and new ones introduced at 15 and 20 years to encourage the use of prostheses with high survival.

Introduction

Varus alignment of the femoral component in total hip arthroplasty (THA) is thought to be a risk factor for implant loosening and early revision surgery. The purpose of this study was to evaluate whether the Exeter stem tolerates varus alignment and assess if this theoretical malalignment has an influence on clinical outcomes.

Introduction

Rationing of orthopaedic services is increasingly being used by Care Commissioning Groups (CCG) within the United Kingdom to restrict the numbers of patients being referred for Total Hip Arthroplasty (THA). In Devon, only patients with an Oxford Hip Score (OHS) less than 20 are referred on for specialist Orthopaedic Review. The aim of this study was to look at long term outcomes after THA to see if this rationing has any rational base to justify its use

Introduction

The Exeter Hip femoral component remains largely unchanged from the original design, introduced in 1970. It is a highly polished, modular, double tapered stem and has undergone various minor modifications to surface, modularity and most recently the taper; changed to the current V40^TM design in 2000.

The effect of any design modification cannot easily be foreseen and greater emphasis is now placed on ensuring appropriate monitoring for such implants.

Introduction

Revision of well cemented femoral components in revision THA can be technically challenging and time consuming. The cement in cement (CiC) technique addresses these issues. Results of femoral components which have undergone multiple CiC revisions have not previously been reported.

Introduction

There is sparse evidence regarding the survivorship beyond 20 years of both uncemented and cemented hip replacements in patients 50 years and under. We report a unique series reviewing 20–26 year follow-up of patients ≤50 years with cemented Exeter THR.

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.

We present 346 consecutive revision procedures for aseptic loosening with acetabular impaction bone grafting (AIBG) and a cemented polyethylene cup. Defects were contained with mesh alone. Mean follow up of 6.6 years, range 8 days-13 years. The Oxford Hip (OHS) and Harris Hip (HHS) scores were collected prospectively. Radiological definition of cup failure was either > 5mm displacement, or > 5° rotation. Cox regression analysis was performed on ten separate patient and surgical factors to determine their significance on survivorship.

Kaplan Meier survivorship at 10 years (42 cases remaining at risk) for aseptic loosening was 87% (95% confidence Interval (CI): 81.6 to 92.2) and 85.6% (95% CI: 80.3 to 90.9) for all revisions. These results are comparable to other reported series utilising AIBG. However, there were 88 cases (25%) that exceeded the radiological migration parameters, but their functional scores were not significantly different to the non-migrators: OHS p=0.273, HHS p=0.16. The latest post-operative mean OHS was 33 (SD 10.66). Female gender (p=0.039), increasing graft thickness (p=0.006) and the use of mesh (p=0.037) were significant risk factors for revision, but differing techniques in graft preparation, including artificial graft expanders (p=0.73), had no significant effect when analysed using Cox regression.

This study utilised NJR primary hip data from the 6^th Annual Report to determine the rate and indication for revision between cemented, uncemented, hybrid and resurfacing prosthetic groups. Regression analysis was performed to identify the influence of gender and ASA grade on these revision rates. Validity of the data was interrogated by exploring for episodes of misclassification.

Background

Since 1991 to 2008 approximately 800,000 Exeter stems have been sold worldwide with 80 reported cases of fracture (neck or stem). This study aimed to determine factors predisposing to fracture.

Impaction bone grafting (IBG) of the acetabulum in cemented primary total hip replacement is a useful technique in the management of acetabular deficiencies. It has the capacity to restore anatomy and bone stock with good long-term outcome. We present 125 consecutive cases of IBG with a cemented polyethylene component. All patients who received full IBG of the acetabulum in primary cemented Exeter total hip replacements and who underwent surgery between August 1995 and August 2003 were identified. All operative and follow-up data was collected prospectively and no patients were lost to follow-up. All patients underwent pre-operative and regular post-operative hip scores with the Harris, Oxford and the modified Charnley scoring systems. Data on indication, surgical technique, socket position and migration and revision was reviewed at a mean follow-up of 7.6 (range 5 to13.4) years.

Between August 1995 and August 2003, 113 patients (85 females) with an average age of 67.8 (range 22.9–99.2) years underwent 125 primary Exeter cemented total hip replacements with IBG of acetabular defects. Acetabular defects were classified according to the AAOS classification as cavitatory in 62 hips and as segmental, requiring application of a rim mesh prior to IBG, in 63 hips. Life tables were constructed demonstrating 86.4% survival of the acetabular component at 13.4 years with revision for any reason as the endpoint and 89.3% survival with revision for aseptic loosening as the endpoint. Of the seven patients who underwent revision for aseptic loosening, all had pre-operative segmental acetabular defects requiring application of a rim mesh. No patient who underwent IBG for a cavitatory defect required revision surgery for aseptic loosening. Survival of the Exeter cemented femoral component was 100% at 13.4 years with revision for aseptic loosening as the endpoint. There were 11 radiographic failures of the acetabular component, which have not been revised at latest review. One of these is symptomatic but not fit for revision surgery, two were asymptomatic at time of death and eight are asymptomatic but under review.

This is the largest series of IBG in the acetabulum in cemented primary THR. Our results suggest that the medium term survival of this technique is good, particularly when used for cavitatory defects. Although there were radiographic failures, these are largely asymptomatic and may not require revision.

The cement in cement technique for revision total hip arthroplasty (THA) has shown good results in selected cases. However, results of its use in the revision of hemiarthroplasty to THA has not been previously reported.

Between May 1994 and May 2007 28 (20 Thompson's and 8 Exeter bipolar) hip hemiarthroplasties were revised to THA in 28 patients using the cement in cement technique. All had an Exeter stem inserted at the time of revision. Clinical and operative data were collected prospectively. Clinical evaluation was by the Charnley, Harris and Oxford. Hip scores and radiographs were analysed post-operatively and at latest follow up.

The mean age at time of hemiarthroplasty revision was 80 (35 to 93) years. The reason for revision was acetabular erosion in 12 (43%), recurrent dislocation in eight (29%), aseptic stem loosening in four (14%), periprosthetic fracture in two (7%) and infection in a further two (7%) patients. No patient has been lost to follow up. Three patients died within three months of surgery. The mean follow up of the remainder was 50 (16 to 119) months. Survivorship with revision of the femoral stem for aseptic loosening as the endpoint was 100%. Three cases (11%) have since undergone further revision, one for recurrent dislocation, one for infection, and one for periprosthetic fracture.

The cement in cement technique can be successfully applied to revision of hip hemiarthroplasty to THA. It has a number of advantages in this elderly population including minimising bone loss, blood loss and operative time.

Removal of well-fixed cement at the time of revision THA for sepsis is time consuming and risks bone stock loss, femoral perforation or fracture. We report our experience of two-stage revision for infection in a series of cases in which we have retained well-fixed femoral cement.

All patients underwent two-stage revision for infection. At the first stage the prostheses and acetabular cement were removed but when the femoral cement mantle demonstrated good osseo-integration it was left in-situ. Following Girdlestone excision arthroplasty (GEA), patients received local antibiotics delivered by cement spacers, as well as systemic antibiotics. At the second stage the existing cement mantle was reamed, washed and dried and then a femoral component was cemented into the old mantle.

Sixteen patients (M:F 5:11) had at least three years follow-up (mean 80 months – range 43 to 91). One patient died of an unrelated cause at 53 months. Recurrence of infection was not suspected in this case. The mean time to first stage revision was 57 months (3 to 155). The mean time between first and second stages was nine months (1 to 35). Organisms were identified in 14 (87.5%) cases (5 Staphylococcus Aureas, 4 Group B Streptococcus, 2 Coagulase negative Staphylococcus, 2 Enterococcus Faecalis, 1 Escheria Coli). At second stage, five (31.2%) acetabulae were uncemented and 11 (68.8%) were cemented. There were two complications; one patient dislocated 41 days post-operatively and a second patient required an acetabular revision at 44 days for failure of fixation. No evidence of infection was found at re-revision. One patient (1/16, 7%) has been re-revised for recurrent infection. Currently no other patients are suspected of having a recurrence of infection (93%).

Retention of a well-fixed femoral cement mantle during two-stage revision for infection and subsequent cement-in-cement reconstruction appears safe with a success rate of 93%. Advantages include a shorter operating time, reduced loss of bone stock, improved component fixation and a technically easier second stage procedure.

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.

Aim

The aim of this study was to determine the medium term survivorship and function of the Exeter Universal Hip Replacement when used in younger patients, a group that is deemed to place high demands on their arthroplasties. Since 1988 The Exeter Hip Research Unit has prospectively gathered data on all patients who have had total hip replacements at the Princess Elizabeth Orthopaedic Hospital. There were 130 Exeter Universal total hip replacements (THR) in 107 patients who were 50 years or younger at the time of surgery and whose surgery was performed at least 10 years before. Mean age at surgery was 42 years (range 17-50 years.) Six patients who had 7 THRs had died, leaving 123 THRs for review. Patients were reviewed at an average of 12.5 years (range 10-17 years). No patient was lost to follow-up.

Purpose

We describe an update of our experience with the implantation of the first 325 Exeter Universal hips. The fate of every implant is known.

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.

The cement in cement technique for revision total hip arthroplasty (THA) has shown good results in selected cases. However results of its use in the revision of hemiarthroplasty to THA has not been previously reported.

Between May 1994 and May 2007 28 (20 Thompson’s and 8 Exeter bipolar) hip hemiarthroplasties were revised to THA in 28 patients using the cement in cement technique. All had an Exeter stem inserted at the time of revision. Clinical and operative data were collected prospectively. Clinical evaluation was by the Charnley, Harris and Oxford hip scores and radiographs were analysed post-operatively and at latest follow up.

The review of the first 325 Exeter Universal hips reported good long term survivorship despite the majority of cups being metal backed. We have reviewed the long term performance of the concentric all-polyethylene Exeter cups used with the Universal Exeter stem.

Clinical and radiographic outcomes of 263 consecutive primary hip arthroplasties in 242 patients with mean age 66 years (range, 18 to 89) were reviewed. 118 cases subsequently died none of whom underwent a revision. Eighteen hips have been revised; thirteen for aseptic cup loosening, three for recurrent dislocation and two for deep infection. Three patients (four hips) were lost to follow-up. The minimum follow-up of the remaining 123 hips was 10 years (mean 13.3 years, range 10–17). Radiographs demonstrated 4 (4%) of the remaining acetabular prostheses were loose. The Kaplan Meier survivorship at 14.5 years with endpoint revision for all causes is 91.5% (95% CI 86.6 to 96.2%). With endpoint revision for aseptic cup loosening, survivorship is 93.3% (CI 88.8 to 97.8%).

This series included a number of complex cases requiring bone blocks and/or chip autograft for acetabular deficiencies. The concentric all polythene Exeter cup and Exeter stem has excellent long term results particularly when factoring in the complexity of cases in this series.

Survivorship of the standard Exeter Universal cemented stem with revision of the femoral component for aseptic loosening as the endpoint has been reported as 100% at 12 years. A version for use in smaller femora, the Exeter 35.5 mm stem, was introduced in 1988. Although also a collarless polished taper, the stem is slimmer and 25 mm shorter than a standard stem.

Between August 1988 and August 2003 192 primary hip arthroplasties were performed in 165 patients using the Exeter 35.5 mm stem. Clinical and operative data were collected prospectively. Clinical evaluation was by the Charnley, Harris and Oxford hip scores and radiographs were analysed post-operatively and at latest follow up.

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.

Purpose: The authors would like to report a technical innovation in cemented hip arthroplasty. The new device, a “rim cutter” (patent pending) was designed in Exeter and aims at improving the surgical technique of insertion of cemented sockets. The principle aim of this innovation is to cut a rim around the periphery of the acetabulum to a set depth so that the flange of the socket seats into this rim and thus by sealing the space underneath the flange, there is a sustained rise in cement injection pressure behind the socket during implantation. This, improves cement macro and micro interlock, creates a congruent cement mantle with no radioluciencies, especially in the highly predictive DeLee-Charnley Zone I.

Materials and methods: A retrospective clinical study was performed in order to assess the radiological result of the use of the rim cutter. Two groups of patients with 30 in each group (consecutive cases) were enrolled in the present study. In group A, the rim cutter device was used while in group B, the acetabulum was prepared without the use of the rim cutter. In all cases an Exeter contemporary cup and stem were used. All cases were evaluated with postoperative radiographs which were analysed to record the anatomic measurements with regard to:

i) centre of rotation of the socket (COR),

These values were compared with the equivalent measurements made for a normal contralateral hip. In addition to these measurements, any radiolucent line in any zone was recorded. The post-operative film was templated using Orthoview (TM, Southampton, Hampshire) software, which is a digital X ray templating system.

Results: The group where the rim cutter was used showed significantly improved radiological parameters. In this group (group A) the socket was placed closer to the normal centre of rotation (COR) compared to the other group (group B) where the rim cutter was not used. This difference was statistically significant (p< 0.0001). Two cases in the non rim cutter group showed radioluciencies in Zone I. Similarly, with regard to the lateralisation of the COR, the implants in the rim cutter group were closer to the COR of the contralateral normal hip The cement mantle was found to be more concentric in the rim cutter group (in group A, more patients had the same width of cement mantle in all Zones) than the non rim cutter group. This difference between the two groups was statistically significant (p< 0.0001).

Conclusions: The introduction of the new “rim cutter” represents a progression in the technique for the preparation of the acetabulum in cemented hip arthroplasty. It indicates a further step, following the introduction of flanged sockets.

Introduction: Recurrent dislocation is a significant problem after total hip replacement. Aetiology is multifactorial and treatment should address the reason for dislocation. The use of a constrained tripolar liner is an option in the surgical treatment of dislocation.

Methods: A retrospective review was carried out of patients who have undergone revision hip surgery and had a constrained liner cemented into the acetabulum. Patients were identified from a computer database. All patients had a constrained liner cemented onto a satisfactory pre-existing cement mantle, cemented into a reconstruction ring, or cemented into a well fixed cementless shell. The Osteonics Tripolar Liner was used in all cases and the outer aspect of the tripolar liner was prepared with a burr to create grooves and thus improve cement interlock. Data collected included demographics, reason for revision, components used, re-revision rate, outcome and survival.

Results: There were 58 cases identified where a cemented constrained liner was inserted at revision hip surgery. Average age at time of surgery was 77years (range 40–94). Reason for use of a constrained liner was recurrent dislocation in over 95% of cases. There were 9 patients who died with less than 2 years follow-up; they were excluded, leaving a study group of 49 cases. Average duration of follow-up was 46months (range 24–76).

There have been 4 infections, one of which required removal of prostheses and 2 stage revision. There was one case of fall post-operatively and fracture of the contra-lateral femoral neck. There have been 3 implant failures requiring re-revision. All failures were due to disarticulation of the liner, 2 of which occurred in the same patient on separate occasions. There have been no revisions for loosening, and there have been no cases of failure at the bone-cement interface or at the cement-cement interface with the cement-in-cement technique. Overall survival of the cemented constrained liner was 91.8% at average 3.8years.

Conclusion: This study demonstrates that a cemented constrained tripolar liner is a viable option in revision hip surgery, particularly in the treatment of recurrent dislocation.

Introduction & methods: The aim of this study was to determine the medium term survivorship and function of the Exeter Universal Hip Replacement when used in younger patients, a group that is deemed to place high demands on their arthroplasties. Since 1988, The Exeter Hip Research Unit has prospectively gathered data on all patients who have had total hip replacements at the Princess Elizabeth Orthopaedic Hospital. There were 130 Exeter Universal total hip replacements (THR) in 107 patients who were 50 years or younger at the time of surgery and whose surgery was performed at least 10 years before. Mean age at surgery was 42y (range 17y to 50y.) Six patients who had 7 THRs had died leaving 123 THRs for review. Patients were reviewed at an average of 12.5 years (range 10 – 17 years). No patient was lost to follow up. Results: At review, 12 hips had been revised. Of these, 9 were for aseptic loosening of the acetabular component and one cup was revised for focal lysis and pain. One hip was revised for recurrent dislocation. One femoral component required revision in 1 case of infection. Radiographs showed that a further 11(10%) of the remaining acetabular prostheses were loose but that no femoral components were loose. Survivorship of stem and cup from all causes was 92.7%, at an average of 12.5 years. Survivorship of stem only from all causes was 99% and from aseptic loosening was 100%.

Conclusion: The Exeter Universal Stem is shown to perform extremely well in the younger patient. No femoral component became loose and only 9 acetabular components were revised for aseptic loosening

Introduction: Pressurization of PMMA can lead to cement extrusion. Although rare, the complications related to cement extrusion (‘CE’) are serious such as neurological, urological and vascular injuries. In a recent study the incidence of CE from acetabulum was found to be 42–50%, most of which was under transverse ligament. We advocate a technique of applying cancellous autograft on the medial floor and under the transverse ligament to provide cancellous surface for cement pressurisation, and to prevent CE. The aim of this study was to review our incidence of CE and radiolucent lines (‘RLL’).

Methods: Study group included 380 consecutive patients undergoing primary implantation of flanged cemented cup with spacers during 2002–2003. The mean age was 68 years. Surgeons of all grades, including junior doctors under supervision, performed the procedure. Early postoperative radiographs were reviewed to identify the incidence, site and extent of CE and incidence of RLL.

Results: We identified CE in 46 radiographs, 35 being inferior, 6 pelvic and 5 along retractors. The mean size of the CE was 240.5 mm². Radiolucent lines (RLL) in any of the Charnley zone were present in 58 cases. Two zone RLL were seen in seven cases (1.8%) and a circumferential radiolucency in one case (0.3%). There was no significant correlation between the grade of the operating surgeon and the incidence of CE (p, 0.15). There was no significant correlation between the grade of operating surgeon and the presence of RLL (p, 0.18).

Discussion: Results of this study confirm that incidence of CE with this technique is significantly less as compared with historic data (12% vs. 42%). Incidence of RLL is also less especially in zone 2 and 3. These findings support our hypothesis that use of autograft to convert acetabulum in contained hemisphere reduces incidence of CE and improves pressurization.

Introduction: Removal of all foreign material is the normal practice at the time of revision arthroplasty for sepsis. However, removal of well fixed bone cement is time consuming, can result in significant bone stock loss and increases the risk of femoral shaft perforation or fracture. We report our results of 2 stage revision hip arthroplasty with retention of a well fixed femoral cement mantle.

Methods: If the femoral cement mantle demonstrated good osseo-integration at first stage it was left in-situ. Following Girdlestone excision arthroplasty (GEA), patients received local and systemic antibiotics and underwent reconstruction at a second stage. At the second stage the femoral component was cemented into the old mantle.

Results: 16 patients (M:F 5:11) had at least 3 years follow up (mean 80 months, range 43 to 91). 1 patient died of an unrelated cause at 53 months. Recurrence of infection was not suspected in this case. The mean time to first stage revision was 57 months (3 to 155). The mean time between first and second stages was 9 months (1 to 35). Organisms were identified in 14 (87.5%) cases (5 Staphylococcus Aureus, 4 Group-B Streptococcus, 2 Coagulase negative Staphylococcus, 2 Enterococcus Faecalis, 1 Escheria Coli). At second stage 5 (31.2%) acetabula were uncemented and 11 (68.8%) were cemented. There were 2 complications, 1 patient dislocated 41 days post-operatively and a second patient required an acetabular revision at 44 days for sudden loss of fixation. No evidence of infection was found at re-revision. Currently no patients are suspected of having a recurrence of infection.

Discussion: In-cement revision of the femoral component following GEA for sepsis is not associated with a higher rate of recurrence of infection. Advantages include a shorter operating time, reduced loss of bone stock, improved component fixation and a technically easier second stage procedure.

Introduction: We describe an update of our experience with the implantation of the first 325 Exeter Universal hips. The fate of every implant was known.

Methods: This is a review of the prospective data collected from the first 325 Exeter Universal stems (309 patients) inserted between March 1988 and February 1990. The procedures were undertaken by surgeons of widely differing experience. Clinical and radiological review was performed at a mean of 15.4 years.

Results: At last review 185 patients had died (192 hips). 104 hips remain in-situ. Survivorship at 17 years with revision for femoral component aseptic loosening was 100% (95% CI 97 to 100), with revision for acetabular component aseptic loosening was 92.85% (95% CI 87.0 to 96.2) and with any re-operation as the endpoint was 83.99% (95% CI 77.1 to 90.27). 12 patients (12 hips) were not able to attend for review due to infirmity or emigration, and scores were obtained by phone (x-rays were obtained in 4 patients). Mean D’Aubigné and Postel scores (Charnley modification) at review were 5.4 for pain and 4.5 for function. The mean Oxford score was 21.46 +/− 9.52 and the mean Harris score 73.35 +/− 17.32. On radiological review there were no femoral component failures. Three sockets (2.9%) were loose as demonstrated by migration or change in orientation (two patients were asymptomatic) and 5 sockets (4.8%) had radiolucent lines in all 3 zones but no migration. There are two patients awaiting socket revision.

Discussion: The high rate of clinical and radiological success of the Exeter Universal stem seen at 12 years is sustained at 17 years. Further cup failures have occurred but overall survivorship remains good. With the favourable long-term behaviour of the original Exeter stem, we feel optimistic that good function of the Universal stem will continue through the third decade.

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.

Retention of well fixed bone cement at the time of a revision THA is an attractive proposition, as its removal can be difficult, time consuming and may result in extensive bone stock loss or fracture. Previously reported poor results of cemented revision THA, however, have tended to discourage Surgeons from performing “cement in cement” revisions, and this technique is not in widespread use.

Since 1989, we have performed a cement within cement femoral stem revision on 354 occasions. The indications for in cement revision included facilitating acetabular revision, replacement of a monoblock stem with a damaged or incompatible head, revision of hemiarthroplasty to THA, component malposition and broken stem. Cement in cement revision was only performed in the presence of well fixed cement with an intact bone-cement interface. An Exeter polished tapered stem was cemented into the existing cement mantle on each occasion.

Follow up of 5 years or longer is available for 175 cases, and over 8 years in 41. On no occasion has a cement in cement femoral stem had to be re-revised during this time for subsequent aseptic loosening. Advantages include preservation of bone stock, reduced operating time, improved acetabular exposure and early post operative full weight bearing mobilisation. This technique has not been used for 1 stage revision of infection.

This experience has encouraged the refinement of this technique, including the development of a new short stem designed specifically for cement within cement revisions. This stem is designed to fit into an existing well fixed cement mantle of most designs of cemented femoral component or hemi-arthroplasty, with only limited preparation of the proximal mantle required. The new stem greatly simplifies cement in cement revision and minimises the risk of distal shaft perforation or fracture, which is otherwise a potential hazard when reaming out distal cement to accommodate a longer prosthesis.

Introduction and Aims: Functional results following revision total hip arthroplasty (THA) for infection may be inferior to those done for aseptic causes. This cross-sectional study compared the results of patients who had two-stage revision for infection using an articulating spacer device, with those of a control group who had revision for aseptic causes.

Method: Patients admitted between December 1997 and December 2000 for two-stage revision of an infected hip replacement using the PROSTALAC articulating spacer were included. They were compared to patients who had revision of both components for aseptic causes over the same time period. Patients with periprosthetic fractures were excluded.

Pre-operative function was assessed using the Charnley score and bone loss was determined from pre-operative radiographs using the Paprowsky femoral and acetabular classifications. At a minimum two years follow-up, quality of life (QOL) was assessed using the WOMAC, Oxford-12 and SF-12 questionnaires. Patient satisfaction and co-morbidity data were also collected.

Results: There were 44 septic and 105 aseptic revision arthroplasties included in the study. There were no differences between the two groups with respect to co-morbidities, Charnley group, pre-operative pain, function or range of movement or loss of acetabular bone stock. The aseptic group had significantly worse femoral bone stock than the septic group (p=0.008).

All infected patients were treated with the PROSTA-LAC system at the first stage, and 40 patients were reimplanted at the second stage procedure. In four cases, a Girdlestone procedure was performed for persistent infection, although two were re-implanted later.

Re-operations in the septic group were required in six patients for: instability (three), fractured femoral component (one), failure of ingrowth (one), and for recurrence of infection (one). Eight aseptic patients had further revisions for: instability (four), failure of component fixation (three), and for periprosthetic fracture (one).

Although the functional results for both groups were good, the results following revision for sepsis were significantly worse. The mean normalised WOMAC score for infected patients was 66.1, compared to 74.4 for aseptic patients (p=0.028) and the mean Oxford score following infection was 22.4 compared to 18.9 for controls (p=0.007). The satisfaction scores following septic revision were also significantly worse (p=0.02).

Conclusion: Use of an articulated spacer in two-stage revision was successful in eradicating infection, allowing re-implantation in more than 90% of patients, and with good recovery of function. However, the functional results and satisfaction scores were significantly worse than those of a matched control group revised for aseptic causes.

Introduction and Aims: The aim was to study: 1) Patients’ ability to recall their pre-operative function following total hip replacement and how this recall alters with time. 2) Whether validated quality of life (QOL) assessment tools can be administered in the post-operative period to assess pre-operative function.

Method: The null hypothesis was: There is no correlation between functional scores collected pre-operatively and those collected post-operatively. Patients admitted for primary and revision hip arthroplasty between September 2002 and January 2003 were included.

Subjects completed the same questionnaire regarding pre-operative function before surgery, and then three days, six weeks and three months post-operatively. The questionnaire was a combination of the WOMAC, Oxford-12 and SF-12 questionnaires. Pearson’s correlation coefficient was used to evaluate the correlation between the pre- and post-surgery scores, and intra-class correlation coefficient (ICC) was used to assess agreement. Test-retest reliability was evaluated by Kendall’s Tau-b statistic.

Results: One hundred and four patients with a mean age of 61 years were included. There were 57 female patients and 47 males, 79 patients had primary hip replacements and 25 had revisions.

The results showed excellent correlation between pre-operative scores and those from all three postoperative time points. Pearson’s correlation coefficient for the WOMAC score was 0.75, 0.78 and 0.87 at three days, six weeks and three months respectively. The values for the Oxford-12 were 0.83, 0.78 and 0.92 at the same time points, and for the SF-12 they were 0.71, 0.63 and 0.81.

Agreement between pre- and post-operative scores was high. The ICC results for the WOMAC score at the same time points were 0.86, 0.88, and 0.93. For the Oxford-12 they were 0.91, 0.88 and 0.96 and for the SF-12 they were 0.83, 0.77 and 0.9.

Kendall’s Tau-b statistic showed high degrees of reliability for all three measures. The values for the WOMAC score at the three time points were 0.64, 0.61 and 0.72, and the results for the Oxford-12 and SF-12 scores were similarly high.

The effects on the statistics of age, sex, unilateral versus bilateral disease, and primary versus revision surgery were assessed, and no differences were found.

Conclusion: We found a high degree of correlation, agreement and test-retest reliability between QOL scores taken before hip replacement and those taken up to three months afterwards. Patients were able to recall their pre-operative functional status after surgery, and accurate pre-operative data may be collected retrospectively during the early post-operative period.