The primary treatment goal for patients with femoroacetabular impingement syndrome, a common hip condition in athletes, is to improve pain and function. In selected patients, in the short term following intervention, arthroscopic hip surgery is superior to a pragmatic NHS- type physiotherapy programme. Here, we report the three-year follow-up results from the FemoroAcetabular Impingement Trial (FAIT), comparing arthroscopic hip surgery with physiotherapy in the management of patients with femoroacetabular impingement (FAI) syndrome. Two-group parallel, assessor-blinded, pragmatic randomised controlled study across seven NHS England sites. 222 participants aged 18 to 60 years with FAI syndrome confirmed clinically and radiologically were randomised (1:1) to receive arthroscopic hip surgery (n = 112) or physiotherapy and activity modification (n = 110). We previously reported on the hip outcome score at eight months. The primary outcome measure of this study was minimum Joint Space Width (mJSW) on Anteroposterior Radiograph at 38 months post randomisation. Secondary outcome measures included the Hip Outcome Score and Scoring Hip Osteoarthritis with MRI (SHOMRI) score. Minimum Joint Space Width data were available for 101 participants (45%) at 38 months post randomisation. Hip outcome score and MRI data were available for 77% and 62% of participants respectively. mJSW was higher in the arthroscopy group (mean (SD) 3.34mm (1.01)) compared to the physiotherapy group (2.99mm (1.33)) at 38 months, p=0.017, however this did not exceed the minimally clinically important difference of 0.48mm. SHOMRI score was significantly lower in the arthroscopy group (mean (SD) 9.22 (11.43)) compared to the physiotherapy group (22.76 (15.26)), p-value <0.001. Hip outcome score was higher in the arthroscopy group (mean (SD) 84.2 (17.4)) compared with the physiotherapy group (74.2 (21.9)), p-value < 0.001). Patients with FAI syndrome treated surgically may experience slowing of osteoarthritisprogression and superior pain and function compared with patients treated non- operatively.
Cam morphology develops during adolescence and predisposes individuals to future hip pain and osteoarthritis. An improved understanding of cam development is required to determine whether the process is modifiable. The aim of this study was to characterise the risk factors, timing, and pathogenesis of cam formation.Background
Hypothesis/Purpose
The aim of this study was to investigate the structural integrity of torn and non-torn human acetabular labral tissue. A total of 47 human labral specimens were obtained from a biobank. These included 22 torn specimens and 25 control specimens from patients undergoing total hip arthroplasty with macroscopically normal labra. The specimens underwent dynamic shear analysis using a rheometer to measure storage modulus, as an indicator of structural integrity.Objectives
Methods
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
Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a group of patients presenting with early medial osteoarthritis of the knee, varus alignment and symptoms for more than 2 years. During development of this practice an association was observed between this phenotype of osteoarthritis and the presence of CAM deformity at the hip. A retrospective cohort study. All patients who underwent HTO since 2011 were identified (n=30). Comparator groups were used in order to establish whether meaningful observations were being made: Control group: The spouses of a high-risk osteoarthritis cohort recruited for a different study at our unit (n=20) Pre-arthroplasty group: Patients who have undergone uni-compartmental arthroplasty (UKA) for antero-medial osteoarthritis (n=20)All patients had standing bilateral full-length radiographs available for analysis using in house developed Matlab-based software for hip measurements and MediCAD for lower limb alignment measurements.Background
Methods
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
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
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
The dGEMRIC index correlates more strongly with the pattern of radiographic joint space narrowing in hip osteoarthritis at five year follow-up than morphological measurements of the proximal femur. It therefore offers potential to refine predictive models of hip osteoarthritis progression. Longitudinal general population studies have shown that femoroacetabular impingement increases the risk of developing hip osteoarthritis, however, morphological parameters have a low positive predictive value. Arthroscopic debridement of impingement lesions has been proposed as a potential strategy for the prevention of osteoarthritis, however, the development of such strategies requires the identification of individuals at high risk of disease progression. We investigated whether delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) predicts disease progression. This imaging modality is an indirect measure of cartilage glycosaminoglycan content.Summary
Introduction
The number of surgical procedures performed each year to treat
femoroacetabular impingement (FAI) continues to rise. Although there
is evidence that surgery can improve symptoms in the short-term,
there is no evidence that it slows the development of osteoarthritis
(OA). We performed a feasibility study to determine whether patient
and surgeon opinion was permissive for a Randomised Controlled Trial
(RCT) comparing operative with non-operative treatment for FAI. Surgeon opinion was obtained using validated questionnaires at
a Specialist Hip Meeting (n = 61, 30 of whom stated that they routinely
performed FAI surgery) and patient opinion was obtained from clinical
patients with a new diagnosis of FAI (n = 31).Objectives
Methods
Hip arthroscopy is a relatively new procedure and evidence to support its use remains limited. Well-designed prospective clinical trials with long-term outcomes are required, but study design requires an understanding of current practice. Our aim was to determine temporal trends in the uptake of non-arthroplasty hip surgery in England between 2001 and 2011. Using procedure and diagnosis codes, we interrogated the Hospital Episode Statistics (HES) Database for all hip procedures performed between 2001 and 2011, excluding those relating to arthroplasty, tumour or infection. Osteotomy procedures were also excluded.Introduction
Methods
Subtle deformities of the acetabulum and proximal femur are recognised as biomechanical risk factors for the development of hip osteoarthritis (OA) as well as a cause of hip and groin pain. We undertook this study to examine relationships between a number of morphological measurements of the acetabulum and proximal femur and the hip pain in a 20-year longitudinal study. In 1989 women of 45–64 years of age were recruited. Each had an AP-Pelvis radiograph at Year-2. These radiographs were analysed using a validated programme for measuring morphology. All morphological measurements were read blinded to outcome. At year 3 all participants were asked whether they experienced hip pain (side specific). This was repeated at visits up to and including 20-years. Logistic regression analysis (with robust standard errors and clustering by subject identifier) was performed using hip pain as a binary outcome. The model adjusted for baseline age, BMI and joint space and included only participants who were pain free on initial questioning.Introduction
Methods
Solid or cystic pseudotumour is a potentially destructive complication of metal on metal (MoM) couples, usually needing revision surgery. However, complete clearance of the pseudotumour is unlikely at times. This prospective case-controlled study reports cases which had recurrence after revision surgery for pseudotumour related to metal on metal hip couples. A total of 37 hips (33 MoM hip resurfacing and four big head MoM total hip arthroplasty (THA)) were revised for pseudotumour during the last 10 years. The patient demographics, time to revision, cup orientation, operative and histological findings were recorded for this cohort. Patients were divided into two groups - group R (needing re-revision for disease progression) and group C (control - no evidence of disease progression). Oxford hip scores (OHS, 0–48, 48 best outcome) were used to assess clinical outcome. The diagnosis of disease progression was based on recurrence of clinical symptoms, cross-sectional imaging, operative and histological findings.Introduction
Methods
Stem geometry is known to influence the outcome in THA; however it is unknown whether the material properties, stiffness in particular can influence the stem stability and outcome. The aim of this study was to measure the influence of stem material properties on micromotion and migration using Roentgen Stereophotogrammetric Analysis (RSA) system. 41 patients were implanted with a collarless polished tapered (CPT) femoral stem (Zimmer, Warsaw, Indiana), which was made of either cobalt-chromium (CoCr) (n=21) or stainless steel (n=20). RSA was used to measure dynamically inducible micromotion (DIMM: difference in stem position in going from double-leg stance (DLS) to single leg stance (SLS)), prosthesis bending (difference in the head-tip distance when going from DLS to SLS), and mean migration of the head, tip and the cement restrictor. DIMM and bending were measured at 3 months, migration at 6, 12 and 24 months. All analyses were carried out using SPSS for windows (v.15.0.0, Chicago. IL, USA). Results were reported as mean ± 95% confidence interval (CI) and regarded as significant when p < 0.05.Introduction
Methods
Since the introduction of 3rd generation Metal-on-Metal-Hip-Resurfacing-Arthroplasty (MoMHRA), thousands of such prostheses have been implanted worldwide in younger patients with end-stage hip osteoarthritis. However, no independent centre has reported their medium-to-long term outcome. The aim of this study is to report the ten year survival and outcome of the Birmingham Hip Resurfacing (BHR), the most commonly used MoMHRA worldwide. Since 1999, 648 BHRs were implanted in 555 patients, the majority of which were male (326). The mean age at surgery was 52.1years (range: 17–82), with primary OA as most common indication (85%). Mean follow up was 7.1years (range: 1–11). The Oxford Hip Score (OHS) and UCLA questionnaires were sent to all patients. Implant survival was established, with revision as the end point. Sub-analysis was performed by gender, femoral component size (small: <45mm, standard: 46–52, large: >53mm) and age at surgery (young:<50yrs, old:>50yrs).Introduction
Methods
Malalignment of some designs of stem is associated with an increased risk of aseptic loosening and revision. We investigated whether the alignment of the cemented polished, double-taper design adversely affected outcome, in a multicentre prospective study. A multicentre prospective study of 1189 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and femoral stem alignment. All patients underwent a primary THR with the Exeter femoral stem (Stryker Howmedica Osteonics, Mahwah, NJ) and a variety of acetabular components. The primary outcome measure was the Oxford hip score (OHS) and change in OHS at five years. Secondary outcomes included rate of dislocation and revision. Radiographic evaluation of the femoral component was also undertaken. The long axis of the Exeter femoral component and the long axis of the femoral canal were located, and the angle at the point of intersection measured. The cementing quality was determined as defined by Barrack et al. Radiolucent lines at the cement-stem and cement-bone interface in the five year radiographs were defined using the zones described by Gruen et al. Subsidence was measured as the vertical dimension of the radiolucency craniolateral to the shoulder of the stem in Gruen zone 1 as described by Fowler et al. Cement fractures were recorded.Introduction
Methods
Studies have suggested that there is a reduction in head-neck-ratio (HNR) associated with MoMHRA. A reduction in HNR at operation would decrease range of movement and increase impingement risk. Impingement could lead to 20 edge loading, increasing wear. Serum ion levels of Chromium (Cr) and Cobalt (Co) are surrogate markers of wear. Although acetabular component orientation has been shown to contribute to wear and PT development, the role of a decrease in HNR has only been highlighted in PT development. This study aimed to measure changes in HNR that occur at resurfacing and determine any gender- and component size-specific differences. In addition it aimed to determine whether changes in HNR could be associated with increased wear. 84 patients (56M: 28F) with unilateral MoMHRA were included. The mean age at surgery was 57 years. The mean femoral component was 49mm. Components were considered small if <45mm, average if between 45–50mm and large if >50mm. Three designs were implanted; BHR, C+ and Recap. The average follow up was 4 years. All patients had Cr/Co levels measured at follow up. Patients were considered to have high ions if Cr and Co levels were 5.1ppb and 4.4ppb respectively. Pre-operative HNR (HNRpre) and the post-operative HNR (HNRpost) were made from the respective pelvic radiographs. Assuming a 2mm thick cartilage layer, the HNR based on the diameter of the articular cartilage pre-operatively (HNRart) was calculated. The immediate changes in HNR as a result of the operation were expressed relative to articular HNR pre-op: HNRartpost=HNRpost–HNRartINTRODUCTION
METHODS
Although simulation studies have shown superior wear properties of metal-on-metal articulations, increased concern exists regarding the excess in-vivo wear of a small number of Metal-on-Metal-Hip-Resurfacing (MoMHRA) implants. Serum ion levels of Chromium (Cr) and Cobalt (Co) are surrogate markers of wear. Risk factors associated with increased wear include female gender, small components, dysplasia, cup orientation outside safe zone and femoral head downsize during surgery with an associated decrease in Head-Neck-Ratio (HNR). However, these factors are interlinked. This study aims to identify the factors that are most important for subsequent wear of MoMHRA, by performing a multivariate analysis. 206 patients (124M: 82F) with unilateral MoMHRA were included in this study. The average follow up was 3.3 years. All patients had Cr/Co levels measured at follow up. Inclination and anteversion of each cup were measured using EBRA. Cups were analysed as being within or outside the previously defined optimum-zone. HNR measurements were made from pre-operative (HNRpre) and post-operative (HNRpost) radiographs. The immediate changes in HNR (downsize/upsize of femoral head) as a result of the operation were expressed as: HNRprepost=HNRpost–HNRpre Multivariate linear regression modelling was used to explore the association between measures of ions with the following predictor variables (gender, age, diagnosis, femoral component size, orientation of the acetabular component, head/neck ratio and position of femoral stem). Analyses were carried out separately for each outcome (Cr and Co). Classification and Regression Tree (CART) models were fitted as a complimentary approach to regression modelling.INTRODUCTION
METHODS
The introduction of hard-on-hard bearings and the consequences of increased wear due to edge-loading have renewed interest in the importance of acetabular component orientation for implant survival and functional outcome following hip arthroplasty. Some studies have shown increased dislocation risk when the cup is mal-oriented which has led to the identification of a safe-zone1. The aims of this prospective, multi-centered study of primary total hip arthroplasty (THA) were to: 1. Identify factors that influence cup orientation and 2. Describe the effect of cup orientation on clinical outcome. In a prospective study involving seven UK centers, patients undergoing primary THA between January 1999 and January 2002 were recruited. All patients underwent detailed assessment pre-operatively as well as post-op. Assessment included data on patient demographics, clinical outcome, complications and further surgery/revision. 681 primary THAs had adequate radiographs for inclusion. 590 hips received cemented cups. The primary functional outcome measure of the study was the change between pre-operative and at latest follow up OHS (OHS). Secondary outcome measures included dislocation rate and revision surgery. EBRA was used to determine acetabular inclination and version. The influence of patient's gender, BMI, surgeon's grade and approach on cup orientation was examined. Four different zones tested as possibly ± (Lewinnek Zone, Callanan's described zone and zones ± 5 and ±10 about the study's mean inclination and anteversion) for a reduced dislocation risk and an optimal functional outcome.INTRODUCTION
METHODS