Revision total hip arthroplasty (THA) is a challenging scenario following complex primary THA for developmental dysplasia of hip (DDH). This study envisages the long-term outcomes of revision DDH and the role of lateral structural support in socket fixation in these young patients who may require multiple revisions in their life-time. Hundred and eighteen consecutive cemented revision THAs with minimum follow up of 5 years following primary diagnosis of DDH operated by a single unit between January 1974 and December 2012 were analysed for their clinical and radiological outcomes.Background
Materials and methods
Custom flanged acetabular components (CFAC) have been shown to be effective in treating complex acetabular reconstructions in revision total hip arthroplasty (THA). However, the specific patient factors and CFAC design characteristics that affect the overall survivorship remain unclear. Once the surgeon opts to follow this treatment pathway, numerous decisions need to be made during the pre-operative design phase and during implantation, which may influence the ultimate success of CFAC. The goal of this study was to retrospectively review the entire cohort of CFAC cases performed at a large volume institution and to identify any patient, surgeon, or design factors that may be related to the long-term survival of these prostheses. We reviewed 96 CFAC cases performed in 91 patients between 2004 and 2017, from which 36 variables were collected spanning patient demographics, pre-operative clinical and radiographic features, intraoperative information, and implant design characteristics. Patient demographics and relevant clinical features were collected from individual medical records. Radiographic review included analysis of pre-operative radiographs, computer tomographic (CT) scans, and serial post-operative radiographs. Radiographic failure was defined as loosening or gross migration as determined by a board-certified orthopedic surgeon. CFAC implant design characteristics and intra-operative features were collected from the design record, surgical record and post-operative radiograph for each case respectively. Two sets of statistical analyses were performed with this dataset. First, univariate analyses were performed for each variable, comprising of a Pearson chi-square test for categorical variables and an independent t-test for continuous variables. Second, a random forest supervised machine learning method was applied to identify the most influential variables within the dataset, which were then used to perform a bivariable logistic regression to generate odds ratios. Statistical significance for this study was set at p < 0.05.Introduction
Methods
Registry data from around the world demonstrates instability following primary THA is a leading indication for revision. However, the burden of THA dislocation is poorly documented and is not routinely recorded or reported at a national level. Our aim was to determine the rate of dislocation following primary THA in contemporary practice and in doing so determining the burden of THA dislocation to the NHS in Wales. We considered all Welsh residents who underwent primary THA from 2011–2016. Via clinical coding linkage using Patient Episode Database for Wales (PEDW), the equivalent of HES data in England, we were able determine re-admission for dislocation, revision THA following dislocation and all cause revision at 1 to 5 years follow-up.Introduction
Method
Short bone-conserving femoral stem implants were developed to achieve more physiological, proximal bone loading than conventional femoral stems. Concerns have arisen, however, that improved loading may be offset by lower primary stability because of the reduced potential area for bony contact. The aim of this study was to determine the primary stability of a novel short femoral stem compared with a conventional femoral stem following cementless total hip arthroplasty (THA), in a prospective, blinded, randomised, controlled trial using radiostereometric analysis.Background
Aims
The study sought to determine the results of labral restoration among patients over age 60 compared to a cohort of younger adults. 21 consecutive patients over age 60 undergoing labral repair with minimum one-year follow-up were compared to a contemporaneous group of 21 patients age 18–55 matched for gender, degree of chondral damage, and associated FAI or dysplasia. Follow-up averaged 18.9 months (12 to 24 months). The study group averaged 63.2 years (61 to 71); with 20 FAI and one dysplasia. 19 had acetabular articular damage (2 grade IV, 11 grade III, 5 grade II, 1 grade I) and 6 had femoral changes (1 grade IV, 5 grade 3). The control group averaged 35.8 years (20 to 54). Average improvement among the study group was 28.1 points modified Harris Hip Score (mHHS) and 37.5 points iHOT; and among the control group, 21.2 points mHHS and 37.1 points iHOT. There was no statistically significant difference between the two groups in the amount of improvement, with statistically and clinically significant improvement noted in both. Two study group patients underwent total hip arthroplasty (THA) at average 10 months with one control group THA at 11 months. All three converted to THA had combined grade IV acetabular and grade III femoral damage. There were no repeat arthroscopies and no complications in either group. We conclude that patients over age 60 can benefit from arthroscopic labral repair with improved outcomes, modest rates of conversion to THA, and small risk of complication. Results are comparable to younger adults. Combined bipolar grade IV or grade III articular damage is a harbinger of conversion to THA, regardless of age.
The pelvis is known to undergo significant movement during Total Hip Replacement (THR). We developed a 4D-tracking device employing an inertial measurement unit (IMU) to track changes in pelvic orientation during THR. The IMU was mounted on the iliac crest in 39 cases with tracking initiated at the commencement of surgery and digital logging of significant intra-operative milestones (i.e. acetabular impaction). The system was validated by videoing a select number of cases and the 4D model linked in real-time. Data were processed using a custom Java-based infrastructure to calculate roll (left/right) and tilt (flexion/extension). 19 patients underwent direct anterior approach (DAA) and 20 posterior approach (PA). Comparing DAA to PA, at acetabular impaction there was mean pelvic roll seen of 3.7°(range 0.5–10.1°) in the DAA group, and 5.6°(range 0.1–16.2°) in the PA group. Mean tilt in the DAA group was 3.7°(range: 0.2–7.1°) and in the PA group was 1.7°(range: 0.2–4.3°). Mean BMI in the DAA group was 25.2(range: 18.4–34.2) and 29.1(range: 21.5–42.4). There was no direct correlation between BMI and the amount of roll or tilt recorded for individual patients. The IMU tracking device provided a useful and real-time method of assessing pelvic orientation during THR via both the DAA and posterior approach. Specific variations in tilt and roll are consistent with previous literature. Significant variation in the pattern of pelvic movement was noted to be dependent on the approach and the position of the patient on the operating table.
The aim of this study was to determine whether patients with
metal-on-metal (MoM) arthroplasties of the hip have an increased
risk of cardiac failure compared with those with alternative types
of arthroplasties (non-MoM). A linkage study between the National Joint Registry, Hospital
Episodes Statistics and records of the Office for National Statistics
on deaths was undertaken. Patients who underwent elective total
hip arthroplasty between January 2003 and December 2014 with no
past history of cardiac failure were included and stratified as
having either a MoM (n = 53 529) or a non-MoM (n = 482 247) arthroplasty.
The primary outcome measure was the time to an admission to hospital
for cardiac failure or death. Analysis was carried out using data
from all patients and from those matched by propensity score.Aims
Patients and Methods
We used the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) to investigate the risk of revision due to prosthetic joint infection (PJI) for patients undergoing primary and revision hip arthroplasty, the changes in risk over time, and the overall burden created by PJI. We analysed revision total hip arthroplasties (THAs) performed due to a diagnosis of PJI and the linked index procedures recorded in the NJR between 2003 and 2014. The cohort analysed consisted of 623 253 index primary hip arthroplasties, 63 222 index revision hip arthroplasties and 7585 revision THAs performed due to a diagnosis of PJI. The prevalence, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression.Objectives
Methods
Synovasure has been designed and validated for use in the diagnosis of periprosthetic joint infection (PJI). It has a reported sensitivity of 97.4% (CI 86.1–99.6%) and specificity of 95.8% (CI 90.5–98.6%), higher than the variable results reported for aspiration by most units. At a cost of £500 per test, we aimed to establish cost-effectiveness and diagnostic accuracy, to determine its role in routine practice. We developed a protocol for pre-operative aspiration or intra-operative use. Prerequisites for entry were a high index of clinical suspicion for PJI and equivocal standard investigations. All cases were discussed at the lower limb arthroplasty MDT and approved only if use would change clinical management. Over 15 months, 36 tests were approved for 22 aspirations (5 hip, 17 knee) and 14 intra-operative cases (7 hip, 7 knee). 10/36 had undergone previous revision surgery. 35/36 cases complied with the protocol. All 22 Synovasure aspirations were negative, corresponding to the microbiology in all but one case; thought to be a contaminant. In the intra-operative group there was one true positive and 12 true negative tests, giving a sensitivity of 100% (95% CI 2.5–100%) and a specificity of 100% (95% CI 73.5–100%). Synovasure influenced decision making in 34/36 procedures. One test failed and in another there was evidence of frank infection. In 11 cases no surgery was performed versus a potential two-stage revision and in 21 cases a single rather than two-stage revision was performed. Resulting in estimated savings of £686,690, offset against a cost of £18,000. The Synovasure test was found to be sensitive and specific and can aid decision-making particularly in complex cases with an equivocal diagnosis of PJI. The use of this test through a robust protocol driven peer review MDT process not only reduces patient morbidity but drives significant efficiency savings.
Image-guided intra-articular hip injection of local-anaesthetic and steroid is commonly used in the management of hip pain. It can be used as a diagnostic and/or therapeutic tool and is of low cost (£75). The aim of this study was to assess how often a hip injection has a therapeutic effect. This is a retrospective, consecutive, case series of intra-articular hip injections performed in a tertiary referral hospital over a 2-year period (2013–4). Patients were identified from the radiology department's prospectively entered database. Clinical information, reason for injection and subsequent management was obtained from hospital records. All patients prospectively reported their pain levels in a numeric pain scale diary (out of 10) at various time points; pre-, immediately post-, 1st day-, 2nd day- and 2 weeks- post-injection. Only patients with complete pain scores at all time points were included (n=200, of the 250 injections performed over study period, 80%). The majority of injections were performed for osteoarthritis (OA) treatment (82%). The pain was significantly reduced from a pre-injection score of 7.5 (SD:2) to 5.0 (SD:3) immediately post-injection(p<0.001); only 24 (11%) reported any worsening of pain immediately post-injection. Pain significantly reduced further to 3.8(SD:3) at 2-weeks post-injection (p<0.001). 50% of patients had at least a 3 point drop in reported pain. No improvement was seen in 18 patients and 10 (5%) reported worse pain at 2-weeks compared to pre-injection. Of the OA cohort, 10% have required repeat injections, 45% required no further intervention and 45% underwent or are due for hip replacement. No immediate complications occurred. Intra-articular hip injection reduced pain in 86% of cases and has delayed any further surgical treatment for at least 2 years in over 50% of OA cases. It is hence a cost-effective treatment modality. Further work is necessary to describe factors predicting response.
High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA). We conducted a systematic review of studies evaluating surrogate markers for predicting long-term outcome in primary THA. Long-term outcome was defined as revision rate of an implant at ten years according to National Institute of Health and Care Excellence guidelines. We conducted a search of Medline and Embase (OVID) databases. Separate search strategies were devised for the Cochrane database and Google Scholar. Each search was performed to include articles from the date of their inception to June 8, 2015.Objectives
Methods
Outcomes following large joint arthroplasty are influenced by the accuracy of implant placement. Patient specific (PS) technology has been used in knee arthroplasty surgery however, its application in total hip arthroplasty remains relatively unexplored. We investigated whether conventional or PS guides, resulted in a more accurate reconstruction of the pre-operative head centre position.Introduction
Aims
Primary hip replacement in young active patients is on the increase. Due to the demands set by the patient, implants used in this patient group should have a proven long-term clinical and radiological outcome. We report our results in patients under the age of 50 using the C-Stem femoral component – a cemented triple tapered polished stem. Since the C-stem femoral component was introduced into clinical practice in 1993, 6906 C-stems have been used in primary hip replacements at our hospital. In this group, 896 patients were under the age of 50 at the time of surgery. We report the first 300 consecutive C-stems from this group. The surgical technique of using a bone block to allow subsidence and clearing of the calcar to increase loading of the proximal femur medially was routinely used together with a femoral cement gun and pressurizer.Introduction
Methods
The Corail stem is a fully HA coated tapered implant that has demonstrated long-term success. On the NJR it has become one of the most commonly used implants in the UK. The aim of our study was to document our experience of the revision of this implant together highlighting some important technical considerations. A retrospective review of a consecutive case series of revision procedures where the Corail stem was extracted. We considered time since implantation, collared or uncollared design, indication for revision, Paprosky classification of femoral deficiency, endo-femoral reconstruction or extended approach/osteotomy, subsequent reconstruction either further primary type implant (cemented or cementless) or revision femoral implant.Introduction
Patients/Materials & Methods
Large acetabular bone defects caused by aseptic loosening are common. Reconstruction of large segmental defects can be challenging. Various implants and operative techniques have been developed to allow further acetabular revision in cases where bone stock is poor. Reconstitution of bone stock is desirable especially in younger patients. The aim of the study was to review the clinical and radiological results of hip revision with structural acetabular bone grafts using fresh frozen allograft and cemented components. Between 1990 and 2014, 151 first time revisions for aseptic acetabular loosening with acetabular reconstruction with a fresh frozen structural allograft and cemented components were performed at our hospital. Graft dimensions, number of screws used and socket coverage by the graft were measured on the post-operative AP radiograph. Follow-up radiographs were analysed for socket loosening, quality of graft union, graft and graft resorption.Introduction
Method
The value of Debridement-Antibiotics-and-Implant-Retention (DAIR) in prosthetic-joint-infection (PJI) is still a matter of debate as most studies to-date are underpowered with variable end-points. In our, tertiary referral, bone infection unit we consider DAIR to be a suitable option in all PJIs with soundly fixed prostheses, despite chronicity. The aims of this study were to define the long-term outcome following DAIR in hip PJI and identify factors that influence it. This is a retrospective consecutive case series of DAIRs performed between 1997 and 2013. Only infected cases confirmed by established criteria were included. Data recorded included patient demographics, medical history (ASA grade, Charlson and KLICC scores), type of surgery performed (DAIR or DAIR + exchange of modular components) and organism grown. Outcome measures included complications, implant survivorship and functional outcome (Oxford Hip Score, OHS).Introduction
Methods
Cross linked polyethylene (XLPE) has gained popularity as a bearing surface of choice for younger patients despite only medium term results being available for wear rates. Concern remains regarding the long-term stability and durability of these materials. In order to address these issues we present the longest radiological and clinical follow-up of XLPE. Since 1986, we have prospectively studied a group of 17 patients (19 hips) that underwent a cemented Charnley low friction arthroplasty using a combination of 22.225mm alumina ceramic femoral head, a modified Charnley flanged stem and a chemically cross-linked polyethylene cup. We now report the 28 year clinical and radiological results.Introduction
Patients/Materials & Methods
The number of total hip replacements taking place across the UK continues to grow. In an ageing population, with people living longer and placing greater strain on their prostheses, the number of peri-prosthetic femoral fractures is increasing. We studied the economic impact this has on a large university teaching hospital. All patients with a peri-prosthetic femoral fracture between 24/11/2006 and 31/5/2014 were identified using theatre databases. Radiographic and case note analysis was performed for each case. Costings from finance department for implants and in-patient stay were obtained.Introduction
Method
Severe osteolysis of the femur secondary to aseptic loosening in hip arthroplasty, remains a difficult revision scenario. Multiple techniques have been developed to aid the surgeon, including restoration of bone stock with impaction bone grafting or strut allografts, various distal fixation prostheses and mega-prostheses. Cemented femoral components, with integration of the cement into the cavitations, has largely fallen out of favour. We examined the long-term outcomes with this technique. Between 1977 and 1990, 109 patients had a cemented stem revision (without bone grafting) for severe femoral osteolysis in the absence of infection. Severe osteolysis was defined as cavitation in a minimum of 4 Gruen zones. Follow-up included functional scoring, radiological assessment and any complications. Further revision and survivorship analysis for stem failure or aseptic loosening of the femoral component were recorded.Introduction
Patients/Materials & Methods
Femoroacetabular Junction Impingement (FAI) describes abnormalities
in the shape of the femoral head–neck junction, or abnormalities
in the orientation of the acetabulum. In the short term, FAI can
give rise to pain and disability, and in the long-term it significantly increases
the risk of developing osteoarthritis. The Femoroacetabular Impingement
Trial (FAIT) aims to determine whether operative or non-operative
intervention is more effective at improving symptoms and preventing
the development and progression of osteoarthritis. FAIT is a multicentre superiority parallel two-arm randomised
controlled trial comparing physiotherapy and activity modification
with arthroscopic surgery for the treatment of symptomatic FAI.
Patients aged 18 to 60 with clinical and radiological evidence of
FAI are eligible. Principal exclusion criteria include previous
surgery to the index hip, established osteoarthritis (Kellgren–Lawrence
≥ 2), hip dysplasia (centre-edge angle <
20°), and completion
of a physiotherapy programme targeting FAI within the previous 12
months. Recruitment will take place over 24 months and 120 patients
will be randomised in a 1:1 ratio and followed up for three years.
The two primary outcome measures are change in hip outcome score
eight months post-randomisation (approximately six-months post-intervention
initiation) and change in radiographic minimum joint space width
38 months post-randomisation. ClinicalTrials.gov: NCT01893034. Cite this article: Aims
Methods
