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
Periprosthetic femoral fracture (PFF) is a potentially
devastating complication after total hip arthroplasty, with historically
high rates of complication and failure because of the technical
challenges of surgery, as well as the prevalence of advanced age
and comorbidity in the patients at risk. This study describes the short-term outcome after revision arthroplasty
using a modular, titanium, tapered, conical stem for PFF in a series
of 38 fractures in 37 patients. The mean age of the cohort was 77 years (47 to 96). A total of
27 patients had an American Society of Anesthesiologists grade of
at least 3. At a mean follow-up of 35 months (4 to 66) the mean
Oxford Hip Score (OHS) was 35 (15 to 48) and comorbidity was significantly
associated with a poorer OHS. All fractures united and no stem needed
to be revised. Three hips in three patients required further surgery
for infection, recurrent PFF and recurrent dislocation and three
other patients required closed manipulation for a single dislocation.
One stem subsided more than 5 mm but then stabilised and required
no further intervention. In this series, a modular, tapered, conical stem provided a versatile
reconstruction solution with a low rate of complications. Cite this article:
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 piriformis muscle is an important landmark
in the surgical anatomy of the hip, particularly the posterior approach
for total hip replacement (THR). Standard orthopaedic teaching dictates
that the tendon must be cut in to allow adequate access to the superior
part of the acetabulum and the femoral medullary canal. However,
in our experience a routine THR can be performed through a posterior
approach without sacrificing this tendon. We dissected the proximal femora of 15 cadavers in order to clarify
the morphological anatomy of the piriformis tendon. We confirmed
that the tendon attaches on the crest of the greater trochanter,
in a position superior to the trochanteric fossa, away from the
entry point for broaching the intramedullary canal during THR. The
tendon attachment site encompassed the summit and medial aspect
of the greater trochanter as well as a variable attachment to the
fibrous capsule of the hip joint. In addition we dissected seven
cadavers resecting all posterior attachments except the piriformis
muscle and tendon in order to study their relations to the hip joint,
as the joint was flexed. At flexion of 90° the piriformis muscle
lay directly posterior to the hip joint. The piriform fossa is a term used by orthopaedic surgeons to
refer the trochanteric fossa and normally has no relation to the
attachment site of the piriformis tendon. In hip flexion the piriformis
lies directly behind the hip joint and might reasonably be considered
to contribute to the stability of the joint. We conclude that the anatomy of the piriformis muscle is often
inaccurately described in the current surgical literature and terms
are used and interchanged inappropriately. Cite this article:
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
A moderator and panel of five experts led an
interactive session in discussing five challenging and interesting patient
case presentations involving surgery of the hip. The hip pathologies
reviewed included failed open reduction internal fixation of subcapital
femoral neck fracture, bilateral hip disease, evaluation of pain
after metal-on-metal hip arthroplasty, avascular necrosis, aseptic
loosening secondary to osteolysis and polyethylene wear, and management
of ceramic femoral head fracture.
Plasma levels of cobalt and chromium ions and
Metal Artefact Reduction Sequence (MARS)-MRI scans were performed
on patients with 209 consecutive, unilateral, symptomatic metal-on-metal
(MoM) hip arthroplasties. There was wide variation in plasma cobalt
and chromium levels, and MARS-MRI scans were positive for adverse reaction
to metal debris (ARMD) in 84 hips (40%). There was a significant
difference in the median plasma cobalt and chromium levels between
those with positive and negative MARS-MRI scans (p <
0.001).
Compared with MARS-MRI as the potential reference standard for the
diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt
or chromium with a cut-off of >
7 µg/l was 57%. The specificity was
65%, positive predictive value was 52% and the negative predictive
value was 69% in symptomatic patients. A lowered threshold of >
3.5 µg/l for cobalt and chromium ion levels improved the sensitivity
and negative predictive value to 86% and 74% but at the expense
of specificity (27%) and positive predictive value (44%). Metal ion analysis is not recommended as a sole indirect screening
test in the surveillance of symptomatic patients with a MoM arthroplasty.
The investigating clinicians should have a low threshold for obtaining
cross-sectional imaging in these patients, even in the presence
of low plasma metal ion levels.
Fracture of a ceramic component in total hip
replacement is a rare but potentially catastrophic complication.
The incidence is likely to increase as the use of ceramics becomes
more widespread. We describe such a case, which illustrates how
inadequate initial management will lead to further morbidity and
require additional surgery. We present the case as a warning that
fracture of a ceramic component should be revised to another ceramic-on-ceramic
articulation in order to minimise the risk of further catastrophic
wear.
We have evaluated the difference in the migration patterns over two years of two cementless stems in a randomised, controlled trial using radiostereophotogrammetric analysis (RSA). The implants studied were the Furlong HAC stem, which has good long-term results and the Furlong Active stem, which is a modified version of the former designed to minimise stress concentrations between the implant and bone, and thus to improve fixation. A total of 23 Furlong HAC and 20 Furlong Active stems were implanted in 43 patients. RSA examinations were carried out immediately post-operatively and at six, 12 and 24 months post-operatively. The subsidence during the first year in the Furlong HAC stem, was approximately one-third that of the Furlong Active stem, the measured mean subsidence of the femoral head at six months being 0.27 mm (95% confidence interval (CI) 0.03 to 0.51) and 0.99 mm (95% CI 0.38 to 1.60), respectively (p = 0.03). One Active stem continued to subside during the second year. All hips, regardless of the type of stem were clinically successful as judged by the Oxford hip score and a derived pain score without any distinction between the two types of stem. The initial stability of the Furlong Active stem was not as good as the established stem which might compromise osseo-integration to the detriment of long-term success. The changes in the geometry of the stem, to minimise stress have affected the attainment of initial stability.
Pseudotumours are a rare complication of hip resurfacing. They are thought to be a response to metal debris which may be caused by edge loading due to poor orientation of the acetabular component. Our aim was to determine the optimal acetabular orientation to minimise the risk of pseudotumour formation. We matched 31 hip resurfacings revised for pseudotumour formation with 58 controls who had a satisfactory outcome from this procedure. The radiographic inclination and anteversion angles of the acetabular component were measured on anteroposterior radiographs of the pelvis using Einzel-Bild-Roentgen-Analyse software. The mean inclination angle (47°, 10° to 81°) and anteversion angle (14°, 4° to 34°) of the pseudotumour cases were the same (p = 0.8, p = 0.2) as the controls, 46° (29° to 60°) and 16° (4° to 30°) respectively, but the variation was greater. Assuming an accuracy of implantation of ± 10° about a target position, the optimal radiographic position was found to be approximately 45° of inclination and 20° of anteversion. The incidence of pseudotumours inside the zone was four times lower (p = 0.007) than outside the zone. In order to minimise the risk of pseudotumour formation we recommend that surgeons implant the acetabular component at an inclination of 45° (± 10) and anteversion of 20° (± 10) on post-operative radiographs. Because of differences between the radiographic and the operative angles, this may be best achieved by aiming for an inclination of 40° and an anteversion of 25°.
The presence of pseudotumours, which are soft-tissue masses relating to the hip, after metal-on-metal hip resurfacing arthroplasty has been associated with elevated levels of metal ions in serum, suggesting that pseudotumours occur when there is increased wear. We aimed to quantify the wear in vivo of implants revised for pseudotumours (eight) and of a control group of implants (22) revised for other reasons of failure. We found that the implant group with pseudotumours had a significantly higher rate of median linear wear of the femoral component at 8.1 μm/year (2.75 to 25.4) than the 1.79 μm/year (0.82 to 4.15; p = 0.002) of the non-pseudotumour group. For the acetabular component a significantly higher rate of median linear wear of 7.36 μm/year (1.61 to 24.9) was observed in the pseudotumour group compared with 1.28 μm/year (0.81 to 3.33, p = 0.001) in the other group. Wear of the acetabular component in the pseudotumour group always involved the edge of the implant, indicating that edge-loading had occurred. Our findings are the first direct evidence that pseudotumour is associated with increased wear at the metal-on-metal articulation. Furthermore, edge-loading with the loss of fluid-film lubrication may be an important mechanism of generation of wear in patients with a pseudotumour.