First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone.

Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging.

Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9-71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%).

The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration.

The UK falls behind other European countries in the early detection of Developmental Dysplasia of the hip (DDH) and there remains controversy surrounding screening strategies for early detection. Clinical detection of DDH is challenging and recognised to be dependent on examiner experience. No studies exist assessing the number of personnel currently involved in such assessments.

Our objective was to study the current screening procedure by studying a cohort of new-born babies in one teaching hospital and assess the number of health professionals involved in neonatal hip assessment and the number of examinations undertaken during one period by each individual.

This was a retrospective observational study assessing all babies born consecutively over a 14-week period in 2020. Record of each initial baby check was obtained from Maternity or Neonatal Badger. Follow-up data on ultrasound or orthopaedic outpatient referrals were obtained from clinical records.

1037 babies were examined by 65 individual examiners representing 9 different healthcare professional groups. The range of examinations conducted per examiner was 1- 97 with a mean of 15.9 examinations per person. 49% individuals examined 5 or less babies across the 14 weeks, with 18% only performing 1 examination. Of the 5 babies (0.48%) treated for DDH, one was picked up on neonatal assessment.

In a system where so many examiners are involved in neonatal hip assessment the experience is limited for most examiners. It is unsurprising that high current rates of late presentation of DDH are observed locally, which are in accordance with published national experience.

The progressive painful and disabling predicament of patients with severe osteoarthritis awaiting a total hip or knee arthroplasty (THA/TKA) results in a decline in muscle mass, strength and function also known as Sarcopenia.

We conducted a cross-sectional, prospective study of patients on the waiting-list for a THA/TKA in the South Australian public healthcare system and compared the findings to healthy participants and patients newly referred from their general practitioners. Participants with a history of joint replacements, pacemakers and cancers were excluded from this study. Outcomes of this study included (i) sarcopenia screening (SARC-F ≥4); (ii) sarcopenia, defined as low muscle strength (hand grip strength M<27kg; F<16kg), low muscle quality (skeletal muscle index M<27%, F<22.1%) and low physical performance (short physical performance battery ≤8). Additional outcomes include descriptions of the recruitment feasibility, randomisation and suitability of the assessment tools.

29 healthy controls were recruited; following screening, 83% (24/29) met the inclusion criteria and 75% (18/24) were assessed. 42 newly referred patients were recruited; following screening, 67% (30/45) met the inclusion criteria and 63% (19/30) were assessed. 68 waiting list patients were recruited; following recruitment, 24% (16/68) met the inclusion criteria and 75% (12/16) were assessed. Preliminary data shows increasing waiting time is associated with higher SARC-F scores, lower hand grip strength and lower muscle quality.

As a pilot study, preliminary data demonstrate that: (1) study subjects’ willingness to participate will enable a larger study to be conducted to establish the prevalence of sarcopenia and the diagnostic cut-off points for this patient group. (2) SARC-F is a suitable tool to screen for sarcopenia. (3) There is a positive correlation between waiting time for a THA/TKA and sarcopenia.

There is growing interest in the peri-operative management of patients with indications for hip and knee arthroplasty in the setting of modifiable risk factors such as morbid obesity, type 2 diabetes mellitus, and smoking. A recent survey of the American Association of Hip and Knee Surgeons (AAHKS) found that 95% of respondents address modifiable risk factors prior to surgery. The aim of this study was to poll Australian arthroplasty surgeons regarding their approach to patients with modifiable risk factors.

The survey tool used in the AAHKS study was adapted for use in the Australian context and distributed to the membership of the Arthroplasty Society of Australia via Survey Monkey.

Seventy-seven survey responses were received, representing a response rate of 64%. The majority of respondents were experienced, high volume arthroplasty surgeons. Overall, 91% of respondents restricted access to arthroplasty for patients with modifiable risk factors. Seventy-two percent of surgeons restricted access for excessive body mass index, 85% for poor diabetic control, and 46% for smoking. Most respondents made decisions based on personal experience or literature review rather than hospital or departmental pressures.

Despite differences in healthcare systems, our findings were similar to those of the AAHKS survey, although their responses were more restrictive in all domains. Differences were noted in responses concerning financial considerations for potentially underprivileged populations. The survey is currently being administered by arthroplasty societies in six other countries, allowing comparison of orthopaedic practice across different healthcare systems around the world.

In conclusion, over 90% of Australian arthroplasty surgeons who responded to the survey address modifiable risk factors prior to surgery.

To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay.

We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year.

270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001).

Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles.

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone.

Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging.

Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9–71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%).

The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration.

Prophylactic pinning of the contralateral hip in unilateral Slipped Upper Femoral Epiphysis (SUFE) persists as a source of debate with the majority of surgeons selecting this option in a proportion of patients whom they regard as at increased risk of a subsequent slip.

Universal prophylactic pinning was introduced in our region in 2005 after an audit of ten years local practice identified 25% of unilateral cases presented with a subsequent slip. This study reports our experience between 2005 and 2020.

In this prospective study, 44 patients presented with 55 affected hips compared with 60 patients with 67 affected hips in the original study. Two patients were excluded as their initial slip had not been treated in our unit. Of the 42 hips seven were bilateral, 34 of the 35 unilateral hips underwent prophylactic pinning. The one exception subsequently underwent prophylactic pinning due to developing pain.

Consistent with our original series, at a minimum follow up of 13 months there have been no complications of infection, fracture, chondrolysis or avascular necrosis subsequent to prophylactic pinning.

Over 25 years 70 patients have undergone prophylactic pinning without complication. On the premise that 25% of our unpinned hips presented with subsequent slips before instituting our policy we estimate that we have prevented 17 subsequent slips over 25 years including the consequences which can be significant. We continue to advocate universal prophylactic pinning as an effective and safe practice in the management of SUFE.

Introduction & aims

The magnitude and pattern of acceptable migration in clinically successful cementless stems is not well understood. Radiostereometric analysis (RSA) is a well-recognised method of assessing implant migration.

Previous studies have reported long term RSA results for cemented stems. The aim of this study was to assess the long-term migration characteristics of the Corail hydroxyapatite-coated cementless stem at 10 years using RSA.

Historically avoidance of avascular necrosis (AVN) has been the primary objective in the management of an acute unstable slipped upper femoral epiphysis (SUFE). When achieved through pinning in situ it was invariably associated with significant malunion. With increasing appreciation of the consequences of femoroacetabular impingement, modern techniques aim to correct deformity and avoid AVN.

Exactly what constitutes an acute unstable SUFE is a source of debate but should represent 5–10% of all cases.

This audit reviewed cases over the past 25 years treated in one region. Of 89 patients with 113 slips, 21 hips were recorded as unstable. During this period the management has evolved from closed reduction and stabilization through pinning in situ, to open reduction.

Radiographic outcomes following these three treatment methods were compared with record of any subsequent surgery in the form of osteotomy or total hip arthroplasty.

Currently the lowest reported incidence of AVN in patients with an acute unstable slip is associated with the Parsch technique which combines open arthrotomy, digital reduction and screw fixation. Early outcomes with this technique are in accordance with those reported in the literature and represents a significant improvement in outcome when compared to earlier techniques used in the management of the severe unstable SUFE.

Prophylactic fixation of the contralateral hip in cases of unilateral slipped capital femoral epiphysis (SCFE) remains contentious. Our senior author reported a 10 year series in 2006 that identified a rate of subsequent contralateral slip of 25percnt; when prophylactic fixation was not performed. This led to a change in local practice and employment of prophylactic fixation as standard. We report the 10 year outcomes following this change in practice.

A prospective study of all patients who presented with diagnosis of SCFE between 2004 and 2014 in our region. Intra-operative complication and post-operative complication were the primary outcomes. 31 patients presented during the study period: 16 male patients and 15 female patients. The mean age was 12.16 (8–16, SD 2.07). 25 patients had stable SCFE and 5 had unstable SCFE. Stability was uncertain in 1 patient. 25 patients had unilateral SCFE and 6 had bilateral SCFE. 24 patients who had unilateral SUFE had contralateral pinning performed. 1 unilateral SCFE did not have contralateral pinning performed as there was partial fusion of physis on contralateral side.

In the hips fixed prophylactically there was 1 cases of transient intraoperative screw penetration into the joint and 1 case of minor wound dehiscence. There were no cases or chondrolysis or AVN. There were no further contralateral slips. This change in practice has been adopted with minimal complication. The fixation of the contralateral side is not without risk but by adopting this model the risk of subsequent slip has been reduced from 25percnt; to 0percnt;.

Training time in Trauma & Orthopaedics is pressured. In this action research project, we develop a feedback/self-reflection model for trainers and trainees, emphasising the contribution both groups make to training, to maximise cohesion and efficacy.

Starting in 2013, trainees completed anonymous feedback forms after each 6-month post. The 18-point quantitative questionnaire covers four training domains: WBA engagement, teaching/feedback, research/audit, operative training.

Consultant trainers completed a once-off corresponding 18-point self-reflection questionnaire. Additionally, trainers were asked for their expectations of and advice for trainees.

Individual trainer profiles were generated from trainee feedback questionnaires, allowing comparison between trainer-group-average, trainer-specific and trainer-self-reflection scores across 18 fields. Trainer profiles were uploaded to ISCP and used for recognition of trainer status for SOAR. This data provided basis for local service provision review with amendments to maximise training efficacy.

Results of thematic analysis of trainer feedback was shared with the trainee group. This and subsequent group self-reflection formed the basis of our ‘Trainee Charter’.

Trainee feedback illustrates high levels of satisfaction with local training (average global score 4.2/5). Strengths included ‘feedback’ and ‘operative teaching’; relative weaknesses included ‘research time’ and ‘OPD teaching’.

The ‘Trainee Charter’ details specific desirable behaviours that embody eight trainee-qualities consistently identified by trainers as important, including ‘honesty’ and ‘being organised’. The charter emphasises trainee contribution to training.

For the first time, trainers have the benefit of serial and individualised feedback. Trainees are better informed and empowered in relation to maximising their own training. Most importantly, both halves of the training-team are explicitly acknowledged.

Following the neonatal examination the 6–8 week ‘GP check’ forms the second part of selective surveillance for developmental dysplasia of the hip (DDH) in the UK. We aim to investigate the effectiveness of this 6–8 week examination for DDH.

This is a observational study including all infants born in our region over 5 years. Early presentation was defined as diagnosis within 14 weeks of birth and late presentation after 14 weeks. Treatment record for early and late DDH as well as referrals for ultrasound (US) following the 6–8 week check were analysed. The attendance at the 6–8 week examination in those patients who went on to present with a late DDH was also analysed.

23112 live births, there were 141 confirmed cases of DDH. 400 referrals for ultrasound were received from GP; 6 of these had a positive finding of DDH. 27 patients presented after 14 weeks and were classified as late presentations. 25 of these patients had attended the 6–8 week examination and no abnormality had been identified. The sensitivity of the examination was 19.4%, its specificity was 98% and it had a positive predictive value of 1.5%

For many years the 6–8 week ‘check’ has been thought of as a safety net for those children with DDH not identified as neonates, however we found that 4 out of every 5 children with DDH were not identified. It is essential efforts are made to impove detection as the long term consequences of late presentation can be life changing.

Introduction

Cementless tapered wedge stems have shown excellent results over the last decade. Distal potting with inadequate proximal fit, as well as failure to achieve biologic fixation has led to thigh pain, loosening and implant failure. To support a variety of patient morphologies a novel tapered wedge stem was designed with reduced distal morphology, maximizing the proximal contact of the grit blasted surface. The objective of the study was to analyze the clinical outcomes of this stem design.

INTRODUCTION

As the demographic of the patient population requiring revision total knee arthroplasty (rTKA) continues to expand, varying preoperative conditions and activity levels need to be taken into consideration when analyzing postoperative outcomes. Factoring in preoperative activity levels can help manage the expectations of patients. The purpose of this study was to analyze the outcomes of low and high activity patients receiving a contemporary rTKA.

Background

Instability and dislocation are some of the most important postoperative complications and potential causes of failure that dual mobility total hip arthroplasty (THA) systems continue to address. Studies have shown that increasing the relative head size provides patients implanted with smaller and larger cups increased stability, greater ROM and a lesser incidence of impingement, without compromising clinical results. The purpose of the current study was to review clinical outcomes in three groups of primary THA patients receiving a dual mobility acetabular shell.

Introduction

Acetabular revision surgery remains a technically demanding procedure with higher failure rates than primary total hip arthroplasty (THA). An acetabular component with three dimensional porous titanium and anatomic screw holes (Figure 1) was designed to allow the cup to be positioned anatomically and provide reliable fixation.

1) INTRODUCTION

Acetabular fixation in cementless total hip arthroplasty (THA) relies on new technology for stability and survivorship of the implant. A highly porous 3D titanium coating was developed with a biologically inspired pore structure to improve initial friction fixation with mechanical stability and long term biological fixation. Ongoing research is investigating potential radiographic phenomenons these coatings produce, resulting in the presence of lucent lines. The purpose of this study was to evaluate clinical and radiographic outcomes of a 3D highly porous-coated titanium acetabular shell.

Introduction

There is limited evidence assessing the effect of the Ankle Foot Orthosis (AFO) on gait improvements in diplegic cerebral palsy. In particular, the effect of the AFO on vertical forces during gait has not been reported. Appropriate vertical ground reaction forces are crucial in enabling children with CP to walk efficiently. This study investigated the effect of AFO application on the vertical forces in gait, particularly the second vertical peak in force (FZ2) in late stance. The force data was compared with the barefoot walk.

The initial management of slipped upper femoral epiphysis (SUFE) can determine the occurrence of longterm disability due to complications. Previous surveys have concentrated on orthopaedic surgeons with a specialist paediatric interest. In many units in Scotland, the initial responsibility for management may be an admitting trauma surgeon with a different subspecialty interest.

All Orthopaedic surgeons in Scotland participating in acute admitting were invited to complete a web based survey to ascertain current practice in the initial management of adolescents presenting with SUFE.

92/144 (64%) of surgeons approached responded. When faced with a severe stable slip, 53% of respondents were happy to pin in situ, whilst 47% would refer either to a colleague or specialist paediatric unit. With an unstable slip of similar magnitude, 38% would self-treat, 18% refer to a colleague and 44% refer to a paediatric orthopaedic unit. Of those treating, 58% stated their treatment was selected irrespective of timing of presentation. 79% of respondents had treated 5 or less cases in the preceding 5 years with 7% more than 10 cases. Universal prophylactic pinning was supported in 29%, selective in 62% and never in 9%.

The responses obtained confirm the variance in management of SUFE that exists amidst acute admitting units in Scotland. Management of a stable slip is uncontroversial except possibly in severe cases. This contrasts with the acute unstable slip, in which various factors are thought to influence the outcome, such as instability and the issue of timing, which are not universally appreciated.

To examine the performance of film compared to DICOM (Digital Imaging and Communications in Medicine) images in the detection and volume appreciation of periprosthetic osteolysis around total knee replacements.

Simulated osteolytic lesions were created around 3 cadaveric total knee replacements and fluoroscopic-assisted radiography as well as Computed Tomography derived imaging taken. Arthoplasty surgeons then reviewed the hard images (AP, Lateral, Paired Obliques and Computed Tomography) on 2 separate occasions regarding the presence and size of lesions. With a minimum of 2 months since the last assessment, DICOM images taken from the same knees were then assessed by the same 3 arthroplasty surgeons in the same manner using Syngo™ Pictured Archive Communication System on hospital computer monitors.

Area under the ROC for lesions detection and kappa statistic for volume appreciation derived from the DICOM assessments were not superior with statistical significance to film assessments. Combinations of imaging that incorporated Paired Oblique views had superior performance in both hard-copy and DICOM imaging.

Digital imaging in this study has not clearly demonstrated superiority to film images for detection and volume appreciation of periprosthetic osteolysis around total knee replacements. The value of the addition of the oblique view to routine assessment is again demonstrated.

This multicenter study compared computer-navigated TKA using either MIS or conventional surgical technique, using a CR fixed bearing knee, Stryker Navigation system and dedicated MIS instrumentation. It was hypothesized that patients would benefit from the MIS technique by shorter recovery periods, less blood loss, faster wound healing and improved mobility during early rehabilitation.

A prospective multicentre double-blind controlled trial included 69 patients matched for age, gender, BMI (MIS n=36, CONV n=33). Assessments at pre-op, 1 week, 3 and 6 months post-op included surgery time, bloodloss, range of motion, Knee Society Score (KSS) and WOMAC, Chair rise test and quadriceps strength. Radiographic analysis included radiographs for lucencies and CAT scans for alignment,

Four patients were lost to follow-up. The MIS group had significantly more prolonged surgery time and blood loss at 24 hours p<0.05. At 6 months mean flexion values for MIS (106,7°±12,91) and CONV 105,92 ±11,58) with no significant differences in flexion ROM between both groups at any time point. KSS scores showed a significant improvement (p<0,01) over time in both groups but no statistical significance between groups. WOMAC score also improved significantly (p<0,01) over time in both groups without reaching statistical significance. A significant decrease of anterior knee pain score was observed over time with no significant difference between both groups. Quadriceps strength recovery was not significant between groups but trended toward faster recovery in the MIS group. X-rays showed stable implants with no progressive radiolucent lines in all patients.

The hypothesis that patients benefit from the MIS technique in the short term was not confirmed by the results of this study. The MIS surgery technique resulted in more blood loss intra-op and in the first 24hours post op as well as an elongated surgery time. The MIS surgery technique also failed to generate clear advantages in clinical or functional outcome that persisted over time.

Introduction

Prophylactic pinning of the contralateral hip in the treatment of slipped upper femoral epiphysis (SUFE) has been shown to be safer than continued observation of the contralateral hip. This treatment remains controversial due to the potential for harm caused to an apparently unaffected hip.

There is evidence that pinning of an already slipped epiphysis causes growth disturbance of the proximal femur, however this has been questioned in that the slip occurs at the hypertrophic layer of the growth plate with no damage to the germative layer.

Osteolysis commonly causes total knee replacement (TKR) failure, often associated with asymptomatic large defects. Detection and size estimation of lytic defects is important for the indications and planning of revision surgery. Our study compares the utility of fluoroscopic-guided plain X-rays and computed topography (CT) in osteolysis detection and volume appreciation.

Three cadaveric specimens were imaged at baseline and following the creation of reamed defects (small, medium and large approximately = 1, 5 & 10 cm3 volume respectively) in the tibia and femur with TKR component implantation at each timepoint. Imaging was with fluoroscopic-guided plain X-rays (Anteroposterior & Lateral [APL], Paired Oblique [OBL]) as well as rapid-acquisition spiral Computed Topography [CT] with a beam-hardening artefact removal algorithm.

Three arthroplasty surgeons estimated the size of the lesion, if present, and confidence (none=0, fair=1, excellent=2) in their assessment on randomly presented images. Each surgeon performed two assessments of each image one month apart.

The accuracy of detecting lesions was determined using the area under the receiver-operating curve (AU-ROC) obtained from a logistic regression with adjustment for assessment sequence, observer, knee and bone. Volume appreciation and assessor confidence were determined using Kappa and the mean average of confidence scores respectively.

The AU-ROC using combinations of either APL/OBL/CT (0.83) or OBL/CT (0.83) resulted in superior detection of lesions (p<0.05) compared to APL (0.75) or OBL alone (0.77). Correct volume appreciation was highest with APL/OBL/CT (kappa=0.52), followed by APL/OBL (0.51) and was superior (p<0.05) to APL (0.29) or CT alone (0.31). Small and medium defects were more often missed than large with all modalities (20.3 vs. 39.7 %). Femoral defects were missed more often than tibial defects (40% vs. 28.7%) and small lesions missed more with CT (50%) versus APL (48%) and Oblique (40%). CT missed 19% of large sized defects, attributed mostly to femoral (29.1%) rather than tibial defects (8.3%)

Greater confidence was derived from use of CT (1.29) and APL (1.19) [Interquartile range (IQR) 1,2] when compared to OBL (.98, IQR 1,1) [p<.01]. Also, there was greater confidence regarding judgement of tibial defects (1.25, IQR 1,2) compared with femoral defects (1.05, IQR 1,1) [p<.01].

Combining all imaging modalities was synergistic and the most sensitive and specific means of defect detection and volume appreciation. CT provided more confidence, superior detection and volume appreciation when used in combination with APL/OBL versus APL/OBL alone. There is also additional value when APL is combined with OBL.

Tranexamic acid is a potent antifibrinolytic which has shown efficacy in reducing blood loss in total knee arthroplasty when administered intravenously. We performed a randomised controlled trial of oral tranexamic acid in total knee arthroplasty in order to assess the blood sparing effect of this preparation.

We investigated the effects of oral tranexamic acid on blood loss in 50 patients (25 treatment arm and 25 placebo) undergoing unilateral total knee replacement in a two year period starting January 2007. The treatment arm received 1500 mg of encapsulated oral tranexamic acid TDS pre-operatively, with the third dose occurring within two hours of surgery, and a fourth dose six hours post surgery. The control arm received an identically encapsulated non-active formulation at the same dosing intervals. Baseline pre-operative haemoglobin and heamatocrit measures were collected. Outcome measures were post-operative haemoglobin and haematocrit taken 12 to 24 hours post operatively and total blood loss in wound drains at 24 hours.

Results showed a non-clinically significant trend towards decreased blood loss and transfusion rates in the treatment arm when compared to placebo. No significant adverse events occurred in relation to the use of oral Tranexamic acid in this study. The perioperative use of oral tranexamic acid in conjuntion with elective total knee arthroplasty appears safe; however, its efficacy as a blood sparing medication is less than that which has been recorded with intravenous dosing. The study supports further consideration of the availability of intravenous tranexamic acid for decreasing blood loss in orthopaedic arthroplasty.

The five year results of 8187 primary total knee replacements undertaken for osteoarthritis in patients under the age of 55 years are presented. The casese were submitted to the Australian Orthopaedic Association National Joint Replacement Registry in the period 1st September 1999 to 31st December 2006. This represents 6.3% of the 130,377 primary knee replacements recorded by the registry for this period.

The five year cumulative revision rate for patients under the age of 55 years was 8.0% (95% CI: 7.2 to 8.9). We compared the results to outcomes of older patients aged over 70 years at the time of surgery. The younger patients have a significantly higher risk of revision in the first five years (hazard ratio of 2.9; 95% CI= 2.59 to 3.26; p< 0.0001). Gender, mode of fixation, the use of cruciate retention or substitution prostheses or patella resurfacing did not significantly affect the rate of revision in those patients aged 55 years or less. Survival of fixed bearing implants was significantly better than that of mobile bearings. The most common reason for revision in this group was loosening (32.3%).

Total knee replacement in patients under the age of 55 years is associated with a much higher risk of revision in the first five years. A decision to proceed with total knee replacement in this age group should be accompanied by a careful explanation of this significantly increased risk compared to knee replacement in older individuals.

Aim: To evaluate the accuracy of ultrasound to locate the gastrocnemius musculotendinous junction (GMTJ) prior to surgery. There is no clear clinical method to precisely localise this junction, either in the paediatric or adult populations.

Method: Twenty calves in 12 paediatric patients with a diagnosis of spastic gastrocnemius muscle (GM) contracture underwent ultrasound examination prior to slide lengthening (Strayer). Surgeons did the ultrasound examination after only a short introduction to the method, using a portable ultrasound machine (Sonosite 180 PLUS) with a linear (5–10 MHz frequency range) transducer.

Only the GMTJ of medial head was located as it usually has a lower attachment and is thicker. The soleus muscle has short multipennate fibres running obliquely between aponeuroses overlying its anterior and posterior surfaces. GM has long parallel fibres and merges distally with the posterior aponeurosis of the soleus muscle. The GMTJ has a unique conical appearance on ultrasound. Pre operative skin markings were compared with the location of GMTJ during surgery.

Results: All ultrasound-guided locations of GMTJ were found to be accurate within 5mm at time of surgery.

Conclusions: This study indicates that ultrasound of the calf muscles by a surgeon prior to surgery is an accurate and reliable way of centering the incision over the GMTJ. The distinct morphological structure of the soleus muscle and overlying GM heads means that even surgeons with little ultrasound experience can perform the examination.

Introduction: Scaphoid non union probably occurs more frequently than we realise. That means that a significant ‘unknown’ population with this condition exists – people who carry on with life with some restrictions, but not enough to seek help. This wide variety of ‘expression’ of the symptoms needs to be borne in mind when considering how best to manage each patient.

Diagnosis: Diagnosis is often obvious. In most cases, plain radiographs are all that are necessary to make the diagnosis confidently. However, whilst radiographs will usually tell you if the scaphoid is healed or not, they will not give you any reliable information on vascularity of the fragments. MRI with contrast is needed to confidently describe the vascularity status, and so give the patient an accurate prognosis for surgery. In cases where union/non union is uncertain, CT will provide unequivocal information if the scan slices are orientated correctly.

I routinely request MRI with contrast before bone graft surgery so that I can give the patient an idea of the likely success of that surgery beforehand.

Decision making: Surgery is not always the best option for patients. Some patients have functioned perfectly well for many years with an un-united scaphoid, and the condition may only have come to light after a moderate re-injury. It is reasonable, in these cases, to treat with an expectant period of splintage. A number of these patients will become comfortable again – although still have an un-united scaphoid. You then have an opportunity to discuss the risks/benefits in a calmer atmosphere. When a recent scaphoid fracture (proven) has progressed to non union, I will always discuss grafting in some detail with each patient. This option is best employed when no degenerative changes have appeared, and therefore recent fractures (younger than 3–5 years) would be considered for grafting. If the non-union is older or of indeterminate age, care should be taken before recommending grafting. Indeed, a ‘successful’ bone grafting of an established and mature non-union with associated degenerative changes is likely to make the patient’s symptoms worse. Remember, one of the main reasons for recommending bone grafting is to reduce the risk of early degenerative disease (SNAC). If degenerative disease is already present, the main indication for grafting is no longer present. There are other surgical alternatives to bone grafting. These will be discussed under their broad categories of ‘motion preserving’ and ‘motion eliminating’ procedures.

Bone grafting: A choice exists between non-vascular-ised and vascularised bone grafting. Traditionally, graft has been harvested from the iliac crest, although, in my own Day Surgery practice, this is no longer possible for operational reasons.

This enforced restriction means that all my bone grafts now come from the distal radius. There is good evidence to support the use of graft from this site – especially in the younger male. As a result, I developed the technique of employing vascularised grafts for all my scaphoid non-unions. Not necessarily because I thought they were any better, but because they were straightforward to perform, offered no disadvantages, and may actually offer an advantage.

I favour the palmar grafts described by Mathoulin because of the biomechanics of the humpback deformity. Scaphoid waist non unions need a palmar wedge to restore their length and shape. Using a corticocancellous palmar wedge graft from the distal radius provides this.

Proximal pole non unions do demand a different approach (both surgically and in decision making). The Zaidemberg dorsal graft is usually more appropriate for these cases, but I recommend developing skills in both techniques to use the right graft for the right indication.

I will illustrate the surgical and rehabilitation techniques I employ in some detail, and discuss the results of these treatments in my personal series.

Salvage: No discussion about ‘management’ of scaphoid non union would be complete without some mention of salvage. However, salvage (in my opinion) is more than just dealing with a failed bone graft. ‘Salvage’ refers to the rescue of whatever function is available and appropriate for each patient. In some cases, I would recommend a plan that some people may regard as ‘salvage’ if it best suited an individual patient.

I will illustrate and justify the salvage techniques I consider in scaphoid non union.

Introduction: Scapholunate dissociation can occur after trauma or as part of a degenerative process. In the acute situation, it can be a difficult finding to recognise. There is little doubt that the best results of treatment in acute cases are obtained after an early primary repair. However, many patients do not present within a timescale considered optimum for primary repair.

I will discuss a personal approach to managing this condition at each stage of presentation, considering how appropriate each alternative treatment may be, and describing in detail what happens to such patients in my practice.

Diagnosis: This is perhaps the biggest challenge in this condition.

As specialist hand surgeons, we pride ourselves on a diagnostic suspicion whenever we are met with an appropriate history or likely injury mechanism. We are able to assess the patient individually, their plain radiographs, MRI arthrograms and arthroscopic findings. The challenge in providing a service for this injury, is to extend that knowledge (or make it readily accessible) to a wider group of generalists in Orthopaedic Surgery, Trauma Surgery and Emergency Medicine.

I will describe my method of assessment with preferred imaging techniques.

Decision making: Decision making in managing scaph-olunate ligament dissociation is not straightforward. A ‘recipe book’ approach will not provide the best for each individual patient, and management must be tailored to patients, injury types, duration and surgeon’s abilities.

I will illustrate some of the pitfalls in decision making with a series of case examples, and explain my personal approach.

Treatment: Operative treatments fall into 3 categories;

Acute repair

I will describe my preferred techniques, which procedures I no longer perform (and why) and rehabilitation programmes in detail for these categories.

Squeaking is a rare complication of hard-on-hard hip bearings. Occasionally the noise is troublesome enough to warrant revision surgery. The purpose of this study is to contribute to the understanding of the mechanism(s) underlying squeaking.

We analyzed 10 alumina ceramic-on-ceramic bearings from squeaking hips collected at revision surgery. The reason for revision was given as squeaking (6 cases) or squeaking and pain (4 cases). Six of the 10 patients were male, average patient age was 48. Bearings were retrieved after an average of 23 months in service (11 to 61 months). There were 4 different designs of acetabular component from 2 different manufacturers. Nine have an elevated metal rim which is proud of the ceramic and one does not. Two bearings were 36mm in diameter, 6 were 32mm and 2 were 28mm.

All 10 bearings showed evidence of edge loading wear. Mean dimensions of the wear patch were 37mm by 12mm on the acetabular component and 32mm by 13mm on the femoral heads. Wear dimension was not related to bearing diameter. Seven of the 10 implants also had evidence of impingement of the femoral neck against the elevated metallic rim or the ceramic insert or both. There was no chipping or fracture of any of the ceramic components.

Squeaking is a recently recognized complication of hard on hard bearing surface. This retrieval study is the first of its kind, to our knowledge attempting to unravel the mechanism of this undesirable complication. Although impingement seems to be present in majority of cases, the latter does not seem to be necessary. Edge loading wear was the common factor in all cases and this may prove to be a critical mechanism.

Aim: The dorsal flange stem was introduced following reports of stem fracture using the Charnley “flat-back” stem. This retrospective study reports the outcome using the Flanged Charnley stem in total hip replacement.

Materials and methods: Between January 1983 to December 1996, 1170 cemented total hip replacements (915 patients) were performed using the flanged Charnley stem. The main indications were osteoarthritis, rheumatoid arthritis and avascular necrosis. There were 532 females and 383 males aged 32 to 83 years (average 70.2 years). 612 patients were alive at an average follow-up of 16.6 years (9 to 22 years). All operations were performed by the trans-trochanteric or antero-lateral approach. Patients were evaluated using the Charnley’s modification of Merle d’Aubigne system.

Results: All patients had an improvement in function following the operation. Aseptic loosening of the stem was noted in 32 patients. Survivorship to revision of the femoral stem was 94% at 10 years (95% CI, 89%–99%) and 90% (95% CI, 81%–99%) at 15 years. The common complications included dislocation, wire breakage and trochanteric non-union. Femoral stem fracture resulted in 1 patient requiring stem revision.

Conclusion: The use of the Flanged Charnley stem in total hip replacement gives good long term outcome.

Introduction: Reported incidence of dislocation following dislocation of hip replacements varies from less than 1% to 8%, the majority (59%) being in the first 3 months and 77% within a year. Recurrent dislocation of total hip arthroplasty is a serious problem for both patient and surgeon. Revision of the components does not guarantee success and there is significant comorbidity associated with major revision surgery. Early techniques of cup augmentation were complicated by screw and augment failure, hence cup augmentation evolved into a low profile polyethylene wedge with a separate metal backing and five screw fixation called the Posterior Lip Augmentation device (PLAD).

Methods: 33 patients in Leeds and Inverness underwent PLAD placement between 1995 and 2000. They were followed up at a minimum of 5 years postoperatively (5–9 years). Where patients had died the cause of death and status of the PLAD at time of death was determined from the notes.

Results: The mean age at time of PLAD insertion was 73 years(43–94). The longest survival was 102 months, the shortest 8 days. Of the 33 patients undergoing PLAD insertion, 3 were lost to follow up, 13 had died by the time of follow up, 7 had been revised and 10 had survived revision free.

Discussion: When considering the revision as an end point, PLAD insertion compares favourably with total revision. As shown by the mortality of the patients in the cohort, a less invasive option for the patient with significant comorbidities is useful to have in the surgical armamentarium.

Introduction: The Pavlik harness is widely used in the management of developmental dysplasia of the hip and its efficacy in the treatment of instability and acetabular dysplasia is well established. There are some hips which although reducible consistently fail to stabilise in a harness irrespective of the age of application. We report three cases in which through altering the method of application of the harness, stability and subsequent normal development was achieved.

Method: Three patients age one week, six weeks and twelve weeks failed to stabilise in a harness applied in the conventional fashion. By rerouting the posterior “abduction strap” in front of the anterior “flexion” strap and attaching it as usual distally we observed improved abduction and more restriction of movement such that the unstable hip was held reduced. Reduction was confirmed by anterior ultrasound. The harness was converted back to the conventional application at four weeks by which time all of the hips had stabilised clinically. It was retained for a further eight weeks.

Results: Significant dysplasia was evident in all three hips at presentation ( alpha angles 32, 48 and 34). At average follow up of 23 months all hips were concentrically reduced with no significant persisting dysplasia nor evidence of avascular necrosis.

Discussion: Early reduction and stabilisation of the femoral head in DDH is important if subsequent intervention is to be minimised and it has been suggested that the more rigid Von Rosen splint is more effective than the Pavlik in achieving this. Our early experience with this simple modification has been successful in treating three unstable hips which would otherwise have failed splintage in our hands. We recommend it as an option to consider in the unstable hip, in conjunction with anterior ultrasound to confirm that reduction has been achieved from the outset.

As part of a user group of a collarless polished tapered stem a database was established in 1993 recording all significant data pre-operatively, intra-operatively and at 1,3,5 and 7 years.

All were primary hip replacements and the study included 38 different surgeons who were free to use the head size, approach and cup of their choosing. All hips had a collarless polished tapered prosthesis (Zimmer inc.).

Data on 2,250 hips were available for analysis and stratification of risk factors for dislocation. Correlation of head size and surgical approach was performed and tested for significance. The patient demographics were standard for a typical arthroplasty study group. Of the surgical approaches used, 13.1% were anterolateral, 27.55% lateral, 23.88% posterior and 35.47% Hardinge. There were no trochanter osteotomies or anterior approaches.

94 (100%) of the hips had a first dislocation occurring in the first two years: 38 during acute stay (40.43%), 45 from acute stay to the first year (47.88%) and 11 during the second year (11.7%). The 22mm head was associated with the greatest risk of dislocation (5.93%, P < 0.001). The risks with the 28mm head (3.05%) and the 26mm head (2.5%) were not significantly different. The lowest risk of dislocation occurred with the lateral approach (2.11%) and the highest with the posterior approach (5.99%). Dislocation rates for the anterolateral and Hardinge approaches (4.1% and 3.28% respectively) were not significantly different. Unfortunately data pertaining to frequency of capsular repair combined with the posterior approach was not available.

The combination of lateral approach and 28mm head was associated with the lowest dislocation risk of 1.56%, while the risk with the posterior approach and 22mm head was the highest at 10.09%.

We report a case of Perthes like changes in the rare disorder of Geleophysic dysplasia and add it to the world literature (24 cases). We found an increased incidence of Perthes at 12% (3/25). Geleophysic dysplasia is characterised by short stature with short limbs distally, normal intelligence, joint stiffness, hepatomegaly and happy facial characteristics. The disease has the clinical and histological appearance of a mucopolysaccharidosis. Perthes changes were seen at the age of 4 years and treated conservatively, with poor clinical results despite the early onset and reasonable radiological improvement. MRI scans of the affected hip did not show any unusual features that differentiate it from normal Perthes disease. The patient also developed carpal tunnel syndrome, which has been seen in with increasing frequency in mucopolysaccharidoses such as Hurlers syndrome, but has not been associated with Geleophysic dysplasia before.

Introduction and Aims: Despite comprehensive literature on knee arthroplasty outcomes there is a paucity of data on patient satisfaction and functional outcomes. We have examined patient satisfaction, function, and time to return to sport and activities of daily living.

Method: A retrospective cohort study using self-assessment forms reviewed all patients who had undergone an Oxford uni-compartmental knee replacement in one centre from 2000 to 2003 at a minimum one-year post-surgery. One hundred and fifty patients with 183 UKRs were reviewed. Twenty-two had bilateral surgery. The cohort contained 76 males and 74 females of mean age 71.5 years (range 52–90). Patients were assessed using the Oxford knee score and a further score of how ‘normal’ their knee felt. Physical activity was assessed according to Grimby’s scale. Sporting activity was assessed with regards to pre- and post-operative frequency, time taken to return to sport, and pain during and after exercise. Time to return to work was also noted.

Results: Mean Oxford knee score for males was 21.6 (range 12–43, SD 8.25) and females 22.8 (range 12–54, SD 9.78). Mean Grimby’s score for males was 4.1 (range 1–6, SD 1.2) and for females 3.6 (range 1–6, SDI.2). Mean time to return to walking as exercise was 7.9 weeks (range 1–47.6, SD 8.9), to swimming was 10 weeks (range 1–34.6, SD 9.9), to cycling 11.8 weeks (range 1–34.7, SD 11) to lawn bowling 24.5 weeks (range 4–104, SD 26.2) and golf 12.3 weeks (range 3–33.3, SD8.73). Return to sport, activities of daily living and return to work positively correlated to the patients’ perception of how ‘normal’ their knee felt.

Conclusion: This study observes activity levels and times to return to ADLs, work and sport that is a guide for patient education and post-operative expectation. When compared to a recent study of total knee arthroplasty patients from our institution the uni-compartmental patients were more satisfied and more active. Patients were more active pre-operatively and post-operatively, they were less likely to give up sport following surgery.

Introduction There are no reports on the epidemiology of revision hip arthroplasty in Australia. The aim of this study was to characterise the epidemiology of revision hip arthroplasty in relation to primary hip replacements in Australia.

Methods This study covered the seven year period 1993/1994 to 1999/2000. Data on all primary hip replacements and revisions done were obtained from the Australian Institute of Health and Welfare using the ICD-9 (81.53) and ICD-10 (Block No. 1492) cartegorisation. The data was stratified by age (five year age groups), sex, year and state or territory. Log linear modelling was used to examine the rate of revision procedures out of the total number of procedures (primary and revision). The effects of gender, age and year were examined in a series of hierarchical log-rate models (Poisson Loglinear Regression).

Results For the period of the study there were 18,027 revision cases and 122,595 cases of primary hip replacement, representing a revision rate of 14%. The rate of increase of primary hip replacements was significantly higher than the rate of increase of revisions (t= −12.1, p< 0.0005). The number of primary hip replacements performed nationally increased by 810 (95% confidence intervals 658,964) a year. The number of revisions increased by only 62 (95% confidence intervals 21,104) a year. The proportion of revisions decreased by 0.3% per year as determined by regression analysis. The hierarchical log-rate models indicate significant interactions between age and gender and beween age and year.

Conclusions The number of primary and revision hip replacements has been increasing with time. The rate of increase of revision hip replacements has been lower. The proportion of hip replacements that are revisions has been gradually dropping, probably due to a greater increase in the number of primary hip replacements.

Aims: To review the effectiveness of the Posterior Lip Augmentation Device (P.L.A.D.) in treating recurrent prosthetic total hip dislocation. Method: We reviewed 36 patients from 2 hip revision surgeons from 2 UK centres who underwent cup augmentation using this device since October 1995. Data were collected from case notes, X-rays and clinical review. All dislocations were posterior (minimum of 3 dislocations). In the majority of cases the abductors were poor or detached, and 35 of the 36 patients had undergone at least one major operation on their hip before a P.L.A.D. was þtted (mean 2.2 operations). Results: The mean age at the time of P.L.A.D. was 73 years (range 47–94). The longest P.L.A.D. follow up is 72 months, and is working well without problems reported by the patient or visible changes on x-ray. A total of 26 out of 36 patients (72.2%) have had a successful correction of their dislocation over this mean period of 21 months (range 8 days Ð 72 months). 10 patients (27.8%) developed signiþcant problems of which 7 (19.4%) required removal of the implant. There were 4 unrelated deaths in our cohort. Conclusions: We feel it has a place in the treatment of recurrent dislocation, particularly in the frail patient, with well-þxed and orientated components, where risks of revision surgery are high and there will be less loading postoperatively

The effect of screw geometry on the pullout strength of Anterior Cruciate Ligament [ACL] reconstruction is well documented. Most research has looked at the effect of screw length and diameter, however other factors such as the degree of taper may also be important. Tapered screws should in theory be associated with increased pullout strength. This has not been demonstrated either clinically or in vitro before. The aim of this study was to compare the pullout strength of ACL reconstruction with a parallel against a tapered screw.

A parallel and tapered screw were manufactured which were identical in all other respects. Sixty superficial digital flexors from the hind legs of sheep were harvested. The tendons were paired and combined to form a quadruple tendon reconstruction of approximately 7mm diameter as measured with graft sizer. An ACL reconstruction was performed on the proximal tibia of 30 bovine knees, which had been harvested in right and left knee pairs, using the quadruple tendon. Fifteen reconstructions were fixed using tapered screws and fifteen with non-tapered screws. The insertion torque of both tapered and non tapered screws were recorded using an instrumented torque screwdriver. The reconstructions were mounted in an Instron materials testing machine with an x-ray bearing system to eliminate horizontal forces, to ensure that the forces were all directed along the line of the tibial tunnel. The maximum pullout strengths were recorded in each case. Five knee pairs were subjected to bone densitometry scanning to ensure that any difference in pull out strength was not due to changes in bone density between right and left knee pairs.

Results indicated that there was no difference between right and left knee pairs [p = 0.58] and that tapered screws were associated with significantly higher pull-out strengths [p=0.007] and insertion torques [p = 0.001].

This study reports the outcome of using the Posterior Lip Augmentation Device (PLAD) for recurrent dislocation of total hip replacement. Twenty-seven patients (16 in Inverness, 11 in Leeds) were treated with the device. The indication for its use was recurrent dislocation of the hip in a patient who had a well-orientated and well-fixed cemented acetabular component. The patients had had between 2 and 14 dislocations before using the PLAD. 24 of the 27 patients had satisfactory control of the dislocations after surgery. The operation was found to be straightforward in most cases with few complications, although one case in the Inverness series has a partial sciatic nerve palsy which is recovering. Of the three failures, two had recurrent dislocation after the use of the PLAD. In one of these, in whom the dislocation followed acetabular reconstruction with impaction grafting, the cup also pulled out due to the semi-captive state after use of the PLAD. Both of these cases were treated by a Girdlestone excision arthroplasty. There was one final failure in whom there has been no further dislocation but following an abduction injury some four months after surgery, progressive cup loosening developed and he awaits revision of the cup. One patient complains of an occasional click in the hip joint and a broken screw is visible on x-ray but there has been no loss of position of the device and no further evidence of dislocation. Overall, we have found that this device gives satisfactory control of recurrent dislocations of the hip but the failures have stressed the need to ensure that the cup fixation is sound before inserting the device.