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.

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

Analysis of registry data shows that few units achieve results better than 99·98% control limits. Implant selection is considered a predictor of outcome variation in joint replacement. We analysed the outcomes of a unit with statistically “better than expected” results and compared to all other units within the National Joint Registry for England, Wales, Northern Ireland and Isle of Man (NJR). We sought to determine whether improved implant survival following primary total hip replacement (THR) is a centre effect or mediated by implant selection.

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

The SPAIRE technique (Spare Piriformis And Internus, Repair Externus) involves a muscle sparing mini-posterior approach to the hip.

Evidence will be prevented that the principle function of the “short external rotator” muscle group is primarily as an abductor and extensor of the flexed hip and has a profound influenced on weight bearing rising and propulsive motions; also that details of the insertions of the piriformis tendon and conjoint insertion of obturator internus and the gemelli (the Quadriceps Coxa) have previously been poorly appreciated. We have developed a surgical technique (SPAIRE) during which the only tendon released, and subsequently repaired, is obturator externus.

The author has carried out the SPAIRE technique for all routine hip arthroplasties for the last 18 months. This cohort has been compared with a matched control group for a comprehensive array of outcome measures. Results show no disadvantage of using the technique. On-table stability is so impressive that when the SPAIRE technique has been used no postoperative restrictions whatsoever are placed on the patient who is immediately encouraged to exercise the hip through a full excursion of movement.

Fewer tendons are damaged using the SPAIRE technique than any other approach to the hip including Direct Anterior and Direct Superior approaches. Randomised prospective studies are on-going using objective measurements of Gait and muscle power as well as functional and patient reported outcomes to prove benefit of the SPAIRE technique. For hemiarthroplasty cases a separate RCT is being undertaken comparing the SPAIRE technique with a direct lateral approach. It is believed that this technique may become the default technique for hemi- and total- hip arthroplasty through a posterior approach and for all hip fracture arthroplasty cases.

The risk of dying following total hip replacement (THR) is low and has declined over the last decades. The influence of comorbidities and worse physical status on mortality leads to the idea that patient-reported health status may also be a predictor of mortality. Although this has not been demonstrated in THR surgery, some studies in other fields have reported an association. The aim of this study was to investigate the relationship between patient-reported health status before THR and the risk of dying up to 5 years post-operatively.

The Swedish Hip Arthroplasty Register runs a nationwide PROMs program including the EQ-5D questionnaire to routinely monitor patients undergoing THR in Sweden. For these analyses, we used register data on 42,862 patients with hip osteoarthritis operated with THR between 2008 and 2012. Relative survival ratio was calculated by dividing the observed survival in the patient group by age- and gender-adjusted expected survival of the general population. Multivariable modelling proceeded with time-transformed Cox proportional hazards. Pre-operative responses to the five EQ-5D dimensions along with age, gender, education status, year of surgery, and hospital type were used as independent variables.

As a group THR patients had a better survival than the general population. Broken down by the five EQ-5D dimensions we observed differentiated survival patters. For all dimensions, those reporting moderate problems (level 2) had higher mortality than those reporting no problems (level 1) and those reporting extreme problems (level 3) had higher mortality than those reporting level 1 or 2.

Worse health status according to the EQ-5D before THR is associated with higher mortality up to five years after surgery. The complexity of the interactions between different patient-factors associated with outcomes complicates accurate assessments of risks and expected benefits for individual patients. EQ-5D responses may be useful in a multifactorial individualized risk assessment before THR.

Prospectively collected data is an important source of information subjected to change over time. What surgeons were doing in 1999 might not be the case anymore in 2016 and this change in time also applies to a number of factors related to the performance and outcome of total hip replacement. We evaluated the evolution of factors related to the patient, the surgical procedure, socio-economy and various outcome parameters after merging the databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare.

Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged with databases including general information about the Swedish population and about hospital care. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length of stay, mortality rate, adverse events, re-operation and revision rates and PROMs.

Most patients were operated because of primary osteoarthritis and this share increased further during the period at the expense of decreasing number of patients with inflammatory OA and hip fracture. Comorbidity and ASA scores increased for each year. The share of all cemented implants has dropped from 92% to 68% with a corresponding increase of all uncemented from 2% to 16%.

Length of stay decreased with about 50 percent to 4.5 days in 2012. The 30- and 90-day mortality rate dropped to 0.4% and 0.7%. Re-operation and revision rates at 2 years were lower in the more recent years. The postoperative PROMs are improving despite the preoperative pain scores getting worse.

Even in Sweden, always been considered as a very conservative country with regards to hip replacement surgery, the demographics of the patients, the comorbidities and the primary diagnosis for surgery are changing. Despite these changes the outcomes like mortality, re-operations, revisions and PROMs are improving.

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

Improvements in function after THA can be evaluated using validated health outcome surveys but studies have shown that PROMs are unreliable in following the progress of individuals. Formal gait lab analysis is expensive, time consuming and fixed in terms of location. Inertial Measurement Units (IMUs) containing accelerometers and gyroscopes can determine aspects of gait kinematics in a portable package and can be used in the outpatient setting (Figure 1). In this study multiple metrics describing gait were evaluated pre- and post THA and comparisons made with the normal population

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

Post-operative gait abnormalities are recognized following total hip arthroplasty (THA). Despite global improvement in functional outcome, gait abnormality persists for a decade or more. In this study 3-dimensional gait analysis (3DGA) was performed using a portable system with Inertial Measurement Units (IMUs) to quantify this abnormality.

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.

Introduction

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

Introduction

Cemented stems have given good results with no difference in outcome when comparing taper slip and composite beam designs in short-term randomised trials. We aimed to ascertain differences in outcome between the different cemented design philosophies using a large-scale registry analysis.

The design of hip replacements is based on the morphology of the proximal femur. Populations living in hard water regions have higher levels of serum calcium and magnesium which promote bone mineralization. A case control study was performed comparing proximal femoral morphology in patients living in soft and hard water regions to determine whether the effect of water hardness had an implication in the future design of hip-prostheses.

The proximal femoral morphology of 2 groups of 70 aged and sex matched patients living in hard and soft water regions at mean age 72.24 (range, 50 to 87 years) were measured using an antero-posterior radiograph of the non-operated hip with magnification adjusted.

The medullary canal diameter at the level of the lesser trochanter was significantly wider in patients living in the hard water region (mean width 1.9 mm wider; p=0.003). No difference was found at the isthmus, Dorr index, or cortical bone ratio.

In conclusion proximal femoral morphology does differ: a wider medullary canal at the level of the lesser trochanter in hard water regions. This size difference is relatively small and is unlikely therefore to affect the mechanics of the current femoral stem prostheses components.

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.

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.

Introduction: Total hip arthroplasty is one of the most frequently performed surgical procedures, with implants usually giving over 90% survival at 10 years. The failure rate is primarily due to aseptic loosening often associated with progressive bone stock loss. Impaction of cancellous morselized allografts with cement can be used for revision total hip arthroplasty in such cases. There is increasing interest in the use of synthetic bone graft substitutes as extenders to allograft due to the shortage and variable quality of allograft. A chemically-pure synthetic calcium phosphate (CaP) allograft extender is compared with allograft alone for acetabular and/or femoral revisions using the Impaction Grafting technique.

Methods: 96 hips in 94 patients underwent revision hip arthroplasty using impaction grafting at 4 sites. Hip revision using impaction grafting was carried out using the Exeter X-Change Instrumentation system, using an Exeter Stem and/or a cemented polyethylene cup. Patients were randomized to receive allograft or CaP plus allograft in a 50:50 volume. Clinical and radiographic assessment was conducted pre-operatively and immediately post-operatively and at 6, 12 and 24 months. Clinical assessments included Harris Hip, Oxford and Charnley modified Merle d’Aubigne scores. Clinical complications were also recorded. Radiographs were assessed for the graft quality, radiolucent lines, lyses or migration, and incorporation of graft. The X-rays were also independently reviewed by an experienced author.

Results: The mean age was 70.2 years (range 41–89 years) with 58 males and 36 females. A total of 40 femoral revisions and 88 acetabular revisions were conducted. There were 46 patients in the ApaPore group, 49 patients in the allograft group and 1 patient who received CaP/allograft and allograft for an acetabular and femoral revision respectively.

No deep infections or adverse events due to the CaP were reported, with no significant difference in complication rates including revision and re-operations. No significant difference in acetabular migration, femoral subsidence, radiolucencies and lyses between the groups was observed. The independent review found no difference between the groups in terms of migration. The bone density was apparently greater for the ApaPore group at 12 months (p=0.001) and 24 months (p=0.012) although the significance of this is unclear. No significant difference in the clinical measures was observed between the groups.

Conclusion: CaP is comparable with allograft in terms of performance and safety when used as an allograft extender for total hip revision arthroplasty using impaction grafting.

The demand for primary hip replacements has grown steadily over the past 20 years and continues to do so. The challenge is to deliver a high quality and cost-effective service by developing short-stay pathways to optimise patient care and outcome.

A four-day hip protocol was established, with attention to detail on analgesia, thrombo-prophylaxis, mobilisation and patient motivation. A multi-disciplinary team was trained to deliver the pathway on a designated ward for primary hip replacements with the aim to discharge patients on the third post-operative day (four day stay in total). Before the initiation of this audit our average stay for primary hips was nine days. The national average stay is 10.6 days, with the top 10 trusts averaging 6.7 days.

In the initial three-month trial, 66 hip replacements (39 females and 27 males) done by the hip team at Princess Elizabeth Orthopaedic Centre in Exeter were audited against the four-day hip protocol. Average age was 72.4 years (range 44 – 92 years). Two patients were discharged on the second post-operative day and another 15 patients on the third post-operative day. As a result, we managed to get 25.8% of the patients home within four days. Overall, the average length of stay was only 6.3 days.

In conclusion, while we only achieved our target in 25.8% of patients, the project improved our overall length of stay remarkably. It is clearly evident that a targeted pathway focused to patient care in all aspects using a multi-disciplinary approach can improve the overall service delivery.