Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Aims

Scoliosis is a lateral curvature of the spine with associated rotation, often causing distress due to appearance. For some curves, there is good evidence to support the use of a spinal brace, worn for 20 to 24 hours a day to minimize the curve, making it as straight as possible during growth, preventing progression. Compliance can be poor due to appearance and comfort. A night-time brace, worn for eight to 12 hours, can achieve higher levels of curve correction while patients are supine, and could be preferable for patients, but evidence of efficacy is limited. This is the protocol for a randomized controlled trial of ‘full-time bracing’ versus ‘night-time bracing’ in adolescent idiopathic scoliosis (AIS).

Aims

Radiostereometric analysis (RSA) is the most accurate radiological method to measure in vivo wear of highly cross-linked polyethylene (XLPE) acetabular components. We have previously reported very low wear rates for a sequentially irradiated and annealed X3 XLPE liner (Stryker Orthopaedics, USA) when used in conjunction with a 32 mm femoral heads at ten-year follow-up. Only two studies have reported the long-term wear rate of X3 liners used in conjunction with larger heads using plain radiographs which have poor sensitivity. The aim of this study was to measure the ten-year wear of thin X3 XLPE liners against larger 36 or 40 mm articulations with RSA.

Introduction

The FitBone lengthening nail (Orthofix UK) is an intramedullary device licensed for the lengthening of long bones in adults in the UK. It contains a motor powered by electricity transmitted via an induction coil placed underneath the skin. It was developed in Germany two decades ago but uptake in the UK has only started more recently. The aim of this study was to review the first cohort of FitBone lengthening nails in a unit with significant experience of other lengthening nails (including PRECICE and Stryde).

Articular cartilage has poor repair potential and the tissue formed is mechanically incompetent. Mesenchymal stromal cells (MSCs) show chondrogenic properties and the ability to re-grow cartilage, however a viable human model for testing cartilage regeneration and repair is lacking. Here, we describe an ex vivo pre-clinical femoral head model for studying human cartilage repair using MSCs.

Human femoral heads (FHs) were obtained following femoral neck fracture with ethical permission/patient consent and full-depth cartilage wells made using a 3mm biopsy punch. Pancreas-derived mesenchymal stromal cells (P-MSC) were prepared in culture media at ~5000 cells/20µl and added to each well and leakage prevented with fibrin sealant. After 24hrs, the sealant was removed and medium replaced with StemPro^TM chondrogenesis differentiation medium. The FHs were incubated (37^oC;5% CO₂) for 3wks, followed by a further 3wks in standard medium with 10% human serum with regular medium changes throughout. Compared to wells with medium only, A-MSCs produced a thin film across the wells which was excised en-block, fixed with 4% paraformaldehyde and frozen for cryo-sectioning.

The cell/tissue films varied in thickness ranging over 20-440µm (82±21µm; mean±SEM; N=3 FHs). The thickness of MSC films abutting the cartilage wells was variable but generally greater (15-1880µm) than across the wells, suggesting an attachment to native articular cartilage. Staining of the films using safranin O (for glycosaminoglycans; quantified using ImageJ) was variable (3±8%; mean±SEM; N=3) but in one experiment reached 20% of the adjacent cartilage. A preliminary assessment of the repair tissue gave an O'Driscoll score of 10/24 (24 is best).

These preliminary results suggest the ex vivo femoral head model has promise for studying the capacity of MSCs to repair cartilage directly in human tissue, although optimising MSCs to produce hyaline-like tissue is essential.

Supported by the CSO (TCS/17/32).

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.

Contemporary indications for unicompartmental knee replacement (UKR) include bone on bone radiographic changes in the medial compartment with relatively preserved lateral and patellofemoral compartments. The role of MRI in identifying candidates for UKR is commonplace. The aim of this study was to assess the relationship between radiographic and MRI pre-operative grade and outcome following UKR.

A retrospective analysis of medial UKR patients from 2017 to 2021. Inclusion criteria were medial UKR for osteoarthritis with pre-operative and post-operative Oxford Knee Scores (OKS), pre-operative radiographs and MRI.

89 patients were included. Whilst all patients had grade 4 ICRS scores on MRI, 36/89 patients had grade 3 KL radiographic scores in the medial compartment, 50/89 had grade 4 KL scores on the medial compartment. Grade 3 KL with grade 4 IRCS medial compartment patients had a mean OKS change of 17.22 (Sd 9.190) meanwhile Grade 4 KL had a mean change of 17.54 (SD 9.001), with no statistical difference in the OKS change score following UKR between these two groups (p=0.873). Medial bone oedema was present in all but one patient. Whilst lateral compartment MRI ICRS scores ranged from 1 to 4 there was no association with MRI score of the lateral compartment and subsequent change in oxford score (P value 0.458). Patellofemoral Compartment (PFC) MRI ICRS ranged from 0 to 4. There was no association between PFC ICRS score and subsequent change in oxford knee score (P value .276)

Radiographs may under report severity of some medial sided knee osteoarthritis. We conclude that in patients with grade 3 KL score that would normally not be considered for UKR, pre-operative MRI might identify grade 4 ICRS scores and this subset of patients have equivalent outcomes to patients with radiographic Grade 4 KL medial compartment osteoarthritis.

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.

Aims

Rates of reverse total shoulder arthroplasty (rTSA) continue to grow. Glenoid bone loss and deformity remains a technical challenge to the surgeon and may reduce improvements in patients’ outcomes. However, there is no consensus as to the optimal surgical technique to best reconstruct these patients’ anatomy. This review aims to compare the outcomes of glenoid bone grafting versus augmented glenoid prostheses in the management of glenoid bone loss in primary reverse total shoulder arthroplasty.

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.

Aims

The purpose of this systematic review was to determine the rates of union for vascularized versus non-vascularized grafting techniques in the operative management of scaphoid nonunion. Secondary aims were to determine the effect of the fixation techniques used, the source of grafting, as well as the influence of fracture location (proximal pole) and avascular necrosis (AVN).

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.

Aims

In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss.

Aims

A typical pattern of blood loss associated with total hip arthroplasty (THA) is 200 ml intraoperatively and 1.3 l in the first 48 postoperative hours. Tranexamic acid (TXA) is most commonly given as a single preoperative dose only and is often withheld from patients with a history of thromboembolic disease as they are perceived to be “high-risk” with respect to postoperative venous thromboembolism (VTE). The TRanexamic ACid for 24 hours trial (TRAC-24) aimed to identify if an additional 24-hour postoperative TXA regime could further reduce blood loss beyond a once-only dose at the time of surgery, without excluding these high-risk patients.

Perioperative glucocorticoids have been used as a successful non-opioid analgesic adjunct for various orthopaedic procedures. Here we describe an ongoing randomized control trial assessing the efficacy of a post-operative methylprednisolone taper course on immediate post-operative pain and function following surgical distal radius fixation. We hypothesize that a post-operative methylprednisolone taper course following distal radius fracture fixation will lead to improved patient pain and function.

This study is a randomized control trial (NCT03661645) of a group of patients treated surgically for distal radius fractures. Patients were randomly assigned at the time of surgery to receive intraoperative dexamethasone only or intraoperative dexamethasone followed by a 6-day oral methylprednisolone (Medrol) taper course. All patients received the same standardized perioperative pain management protocol. A pain journal was used to record visual analog pain scores (VAS-pain), VAS-nausea, and number of opioid tablets consumed during the first 7 post-operative days (POD). Patients were seen at 2-weeks, 6-weeks, and 12-weeks post-operatively for clinical evaluation and collection of patient reported outcomes (Disabilities of the Arm, Shoulder and Hand Score [qDASH]). Differences in categorical variables were assessed with χ2 or Fischer's exact tests. T-tests or Mann-Whitney-U tests were used to compare continuous data.

Forty-three patients were enrolled from October 2018 to October 2019. 20 patients have been assigned to the control group and 23 patients have been assigned to the treatment group. There were no differences in age (p=0.7259), Body Mass Index (p=0.361), race (p=0.5605), smoking status (p=0.0844), or pre-operative narcotic use (p=0.2276) between cohorts. 83.7% (n=36) of patients were female and the median age was 56.9 years. No differences were seen in pre-operative qDASH (p=0.2359) or pre-operative PRWE (p=0.2329) between groups. In the 7 days following surgery, patients in the control group took an average of 16.3 (±12.02) opioid tablets, while those in the treatment group took an average of 8.71 (±7.61) tablets (p=0.0270). We see that significant difference in Opioid consumption is formed at postoperative day two between the two groups with patients in the control group taking. Patient pain scores decreased uniformly in both groups to post-operative day 7. Patient pain was not statistically from POD0 to POD2 (p=0.0662 to 0.2923). However, from POD4 to POD7 patients receiving the methylprednisolone taper course reported decreased pain (p=0.0021 to 0.0497). There was no difference in qDASH score improvement at 6 or 12 weeks. Additionally, no differences were seen for wrist motion improvement at 6 or 12 weeks.

A methylprednisolone taper course shows promise in reducing acute pain in the immediate post-operative period following distal radius fixation. Furthermore, although no statistically significant reductions in post-operative opioid utilization were noted, current trends may become statistically significant as the study continues. No improvements were seen in wrist motion or qDASH and continued enrollment of patients in this clinical trial will further elucidate the role of methylprednisolone for these outcomes.

Power production in the terminal stance phase is essential for propelling the body forward during walking and is generated primarily by ankle plantarflexion. Osteoarthritis (OA) of the ankle restricts joint range of motion and is expected to reduce power production at that ankle. This loss of power may be compensated for by unaffected joints on both the ipsilateral and contralateral limbs resulting in overloading of the asymptomatic joints. Total ankle arthroplasty (TAA) has been shown to reduce pain and has the potential to restore range of motion and therefore increase ankle joint power, which could reduce overloading of the unaffected joints and increase walking speed. The purpose of this study was to test the hypothesis that ankle OA causes a loss of power in the affected ankle, compensatory power changes in unaffected lower limb joints, and that TAA will increase ankle power in the repaired ankle and reduce compensatory changes in other joints.

One hundred and eighty-three patients (86 men, 97 women with average ages 64.1 and 62.4 years respectively) requiring surgical intervention for ankle OA were prospectively enrolled. Implant selection of either a fixed (INBONE or Salto Talaris) or mobile (STAR) bearing implant was based on surgeon preference. Three-dimensional kinematics and kinetics were collected prior to surgery and one year post-operatively during self-selected speed level walking using an eight-camera motion capture system and a series of force platforms. Subject walking speed and lower extremity joint power during the last third of stance at the ankle, knee, and hip were calculated bilaterally and compared before and after surgical intervention across the entire group and by implant type (fixed vs. mobile), and gender using a series of ANOVAs (JMP SAS, Cary, NC), with statistical significance defined as p < 0 .05.

There were no gender differences in age, walking speed, or joint power. All patients increased walking as a result of surgery (0.87 m/s±0.26 prior to surgery and 1.13 m/s±0.24 after surgery, p < 0 .001) and increased total limb power. Normalized to total power (which accounts for changes in speed and distribution of power production across joints), prior to surgery the affected ankle contributed 19%±10% of total power while the unaffected ankle contributed 42%±12% (P < 0 .001). After surgery, the affected ankle increased to 25%±9% of total power and the unaffected ankle decreased to 38%±9% of total (P < 0.001). Other joints showed no significant power changes following surgery. Fixed bearing implants provide greater surgical ankle power improvement (61% versus 29% increase, p < 0 .002). Much of that change was due to the fact that those that received fixed-bearing implants had significantly lower walking speed and power before surgery.

Ankle OA reduced ankle power production, which was partially compensated for by the unaffected ankle. TAA increases walking speed and power at the affected ankle while lowering power production on the unaffected side. The modifications in power production could lead to increased physical activity and reduced overloading of asymptomatic joints.

Background

91% of blood loss in Total Hip Replacement (THR) occurs in the period after skin closure and the first 24 post-operative hours. TRAC-24 was established to identify if an additional 24-hour post-operative oral regime of Tranexamic acid (TXA) is superior to a once-only intravenous dose at surgery.

The purpose of this population-based study was to determine the association between morbid obesity and 10-year mortality and complications in patients undergoing primary THA.

A cohort study of 22,251 patients, aged 45–74 years old, treated with primary THA between 2002 and 2007 for osteoarthritis, was conducted using Ontario administrative healthcare databases. Patients were followed for 10 years. Risk ratios (RRs) of mortality, reoperation, revision, and dislocation in patients with body mass index (BMI) > 45 kg/m2(morbidly obese patients) compared with BMI ≤45 kg/m2 (non-morbidly obese) were estimated.

3.3% of the cohort (726) was morbidly obese. Morbidly obese patients were younger (mean age 60.6 vs. 63.3, P-value < 0 .001) and more likely to be female (63.9% vs. 52.2%, P-value < 0 .001), compared with non-morbidly obese patients. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% CI 1.18, 1.62). Risks of revision (RR 1.43, 95% CI 0.96, 2.13) and dislocation (RR 2.38, 95% CI 1.38, 4.10) were higher in morbidly obese men, compared with non-morbidly obese men, there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women, compared to non-morbidly obese women (RR 1.60, 95% CI 1.05, 2.40), there was no association between obesity and reoperation in men.

Morbidly obese patients undergoing primary THA are at higher risks of long-term mortality and complications. There were differences in complication risk by sex. Results should inform evidence-based perioperative counseling of morbidly obese patients considering THA.

Background

Improving primary care management of musculoskeletal (MSK) pain is a priority. A pilot cluster RCT tested prognostic stratified care for patients with common MSK pain presentations, including low back pain, in 8 UK general practices (4 stratified care; 4 usual care) with 524 patients. GPs in stratified care practices were asked to use i) the Keele STarT MSK tool for risk-stratification and ii) matched treatment options for patients at low-, medium- and high-risk of persistent pain. A linked qualitative process evaluation explored patients' and GPs' views and experiences of stratified care.

Purpose

Back pain is the primary cause of disability worldwide yet surprisingly little is known of the underlying pathobiology. We conducted a genome-wide association study (GWAS) meta-analysis of chronic back pain (CBP). Adults of European ancestry from 15 cohorts in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and UK Biobank were studied.

Background

Distal femoral replacements (DFR) are used in children for limb-salvage procedures after bone tumor surgery. These are typically modular devices involving a hinged knee axle that has peripheral metal-on-polyethylene (MoP) and central metal-on-metal (M-M) articulations. While modular connections and M-M surfaces in hip devices have been extensively studied, little is known about long-term wear or corrosion mechanisms of DFRs. Retrieved axles were examined to identify common features and patterns of surface damage, wear and corrosion.

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.

Introduction

In 2010, a widely used metal-on-metal hip implant was voluntarily recalled from the market by the manufacturer. Our lab performed detailed retrieval analysis of 548 of the explanted devices and 165 periprosthetic tissue specimens. We reported a high degree of variability in the multiple measurements that we performed on the components, including volumetric wear.

Other studies using semi-quantitative tissue grading methods to describe the histology of the periprosthetic tissues from metal-on-metal hips have looked for relationships between component wear and histological features. Grammatopoulos et al found higher ALVAL scores in 45 hip resurfacing patients with pseudotumors compared to 11 without pseudotumors and a moderately positive correlation between wear and the histological rankings for tissue necrosis and lymphocytic response.

We examined correlations between the component wear measurements from retrieval analysis and the tissue features in this large group of one metal-on-metal hip design.

Since the introduction of national guidelines in 2009 encouraging the use of total hip arthroplasty (THA) to treat intracapsular neck of femur fractures there has been no population-based studies into the surgical outcomes for this indication. This study aims to calculate the complication rates for THA when performed for a fractured neck of femur and compare them to THA performed for primary osteoarthritis in the same population.

The Scottish Arthroplasty Project was used to identify all THAs performed in Scotland for neck of femur fracture and osteoarthritis between 1st of January 2009 and 31st December 2014. Dislocation, infection and revision rates at 1 year were calculated.

The rate of dislocation, infection and revision at 1 year were all significantly increased among the fracture neck of femur cohort. In total 44046 THAs were performed, 38316 for OA and 2715 for a neck of femur fracture. 2.1% of patients (n=57) who underwent a THA for a neck of femur fracture suffered a dislocation in the 1st year postoperatively, compared to 0.9% (n=337) when the THA was performed for osteoarthritis. Relative Risk of dislocation: 2.3870 (95% C.I. 1.8077–3.1252, p value <0.0001). Relative Risk of infection: 1.4561 (95% C.I. 1.0496–2.0200, p value 0.0245) Relative Risk of revision: 1.4807 (95% C.I. 1.0308–2.1268, p value 0.0336).

This is the first time a dislocation rate for THA performed for a neck of femur fracture has been calculated for an entire population. As the number of THAs for neck of femur fracture increases this dislocation rate will have clinical implications.

INTRODUCTION

Loosening is a major cause for revision in uncemented hip prostheses due to insufficient primary stability. Primary stability after surgery is achieved through press-fit in an undersized cavity. Cavity preparation is performed either by extraction (removing bone) or compaction (crushing bone) broaching. Densification of trabecular bone has been shown to enhance primary stability in human femora; however, the effect of clinically used compaction and extraction broaches on human bone with varying bone mineral density (BMD) has not yet been quantified. The purpose of this study was to determine the influence of the broach design and BMD on the level of densification at the bone-cavity interface, stem seating, the bone-implant contact area and the press-fit achieved.

INTRODUCTION

The restoration of the anatomical hip rotation center (HRC) has a major influence on the longevity of hip prostheses. Deviations from the HRC of the anatomical joint after total hip arthroplasty (THA) can lead to increased hip joint forces, early wear or loosening of the implant. The contact conditions of acetabular press-fit cups after implantation, including the degree of press-fit, the existence of a polar gap and cup orientation, may affect the HRC restoration, and therefore implant stability. The aim of this study was to determine the influence of acetabular press-fit, polar gap and cup orientation on HRC restoration during THA.

Background and objectives

Low back pain (LBP) is a major health challenge globally. Research has identified common trajectories of pain over time. We aimed to investigate whether trajectories described in one primary care cohort can be confirmed in another, and to determine the prognostic value of factors collected 5 years prior to the identification of the trajectory.

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.

Recently, a special type of surface pitting found on metal implants was proposed to arise from “inflammatory cell-induced” corrosion (ICI, Figure 1) (1, 2). The actual mechanism of this was unknown, but similar features were suggested to be artefacts of electrocautery damage from revision surgery (3). Under lab conditions and without the influence of any cells, we aimed to reproduce the same surface pits and structures with electrocautery.

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.

Young osteoarthritic male patients have been considered the ideal candidates for Metal-on-Metal (MoM) hip resurfacing arthroplasty (HRA), based on generally good long term results. In contrast, hip resurfacing in young female patients has become controversial. Recently, one implant manufacturer withdrew 46mm and smaller components, citing poorer than expected 10 year outcomes in females with smaller HRAs. Whether this difference is related to gender or to component size is still debated. Possible reasons for higher failure rates reported in females include higher rates of hip dysplasia, poorer bone quality and the risk of higher wear in some smaller sized implants with low cup coverage angles.

We reviewed HRA revision specimens with the aim of comparing mode of failure, time to revision, femoral cement characteristics and acetabular bone attachment in specimens larger and smaller than 46mm and from male versus female patients.

Valgus unloader knee braces are a conservative treatment option for medial compartment knee osteoarthritis (OA). These braces are designed to reduce painful, and potentially injurious compressive loading on the damaged medial side of the joint through application of a frontal-plane abduction moment. While some patients experience improvements in pain, function, and joint loading, others see little to no benefit from bracing [1]. Previous biomechanical studies investigating the mechanical effectiveness of bracing have been limited in either their musculoskeletal detail [2] or incorporation of altered external joint moments and forces [3]. The first objective was to model the relative contributions of gait dynamics, muscle forces, and the external brace abduction moment to reducing medial compartment knee loads. The second objective was to determine what factors predict the effectiveness of the valgus unloading brace.

Seventeen people with knee OA (8 Female age 54.4 +/− 4.2, BMI 30.00 +/− 4.0 kg/m², Kellgren-Lawrence range of 1–4 with med. = 3) and 20 healthy age-matched controls participated in this study which was approved by the institutional ethics review board. Subjects walked across a 20m walkway with and without a Donjoy OA Assist knee brace while marker trajectories, ground reaction forces, and lower limb electromyography were recorded. The external moment applied by the brace was estimated by multiplying the brace deformation by is pre-determined brace-stiffness. For each subject, a representative stride was selected for each brace condition. A generic musculokeletal model with two legs, a torso, and 96 muscles was modified to include subject-specific frontal plane alignment and medial and lateral contact locations [4]. Muscle forces, and tibiofemoral contact forces were estimated using static optimization [4]. We defined brace effectiveness as the difference in the peak medial contact force between the braced and the unbraced conditions. A stepwise regression analysis was performed to predict brace effectiveness based on: X-ray frontal plane alignment, medial joint space, KL grade, mass, WOMAC scores, unbraced walking speed, trunk, hip and knee joint angles and moments.

The OA Assist brace reduced medial joint loading by approximately 0.1 to 0.2 BW or roughly 10%, during stance. This decrease was primarily due to the external brace abduction moment, and not changes in gait dynamics, or muscle forces. The brace effectiveness could be predicted (R²=0.77) by the KL grade, and the magnitude of the hip adduction moment in early stance (unbraced). The brace was more effective for those that had larger hip adduction moments and for those with more severe OA.

The valgus knee brace was found to reduce the medial joint contact force by approximately 10% as estimated using a musculoskeletal model. Bracing resulted in a greater reduction in joint contact force for those who had more severe OA while still maintaining a hip adduction moment similar to that of healthy controls.

Aims

The appropriate management for patients with a degenerative tear of the rotator cuff remains controversial, but operative treatment, particularly arthroscopic surgery, is increasingly being used. Our aim in this paper was to compare the effectiveness of arthroscopic with open repair of the rotator cuff.

Aims

The increased in vivo resistance to wear of highly crosslinked polyethylene (HXLPE) in total hip arthroplasty (THA) has led to an increased use of larger articulations which have been shown to reduce the incidence of early dislocation. To date, there are few reports of the wear of larger articulations using second generation HXLPE liners. Our prospective cohort study measured the bedding-in and early wear of large (36 mm and 40 mm diameter) articulations involving a second generation X3 HXLPE liner and compared our findings with previous clinical and in vitro studies of the same material.

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.

Avascular necrosis of the femoral head (AVN) is associated with collapse of the femoral head and arthritic degeneration of the joint. The combination of an implant inserted into the femoral head that provides mechanical support and bone grafting to promote bone formation may offer a possible joint-preserving solution1. Seventeen such procedures were performed between November 2012 and March 2014 during an IRB approved clinical trial. Thirteen out of 18 patients remained unrevised at a minimum of 12 months; the results of radiographic and histological analysis of four revisions are presented.

The investigational device (Figure 1) was developed as a joint preserving treatment for AVN with a clinical grade of IIC or less according to the ARCO grading system2.

The device consisted of a braided spherical Nitinol cage with a Titanium / Nitinol orientation feature. It was implanted using fluoroscopic navigation into a spherical cavity cut into the femoral head via an 11mm diameter access tunnel. Once deployed, the implant was filled with a lightly impacted mixture of autologous bone graft and bone marrow soaked Conduit TCP (DePuy CMW, Blackpool, UK). The implant's purpose was to provide mechanical support to the weakened subchondral surface while the bone graft mixture re-integrated with the host bone.

The retrieved femoral heads were trimmed to leave approximately 3mm of bone around the implant, dehydrated, embedded in methacrylate resin, sectioned and thinned into 50–70µm coronal slices for histological analysis. The following observations were made (Figure 2):

Case 1 (Female, age 70, ARCO IIB, revised after 2 days): The patient was revised for spontaneous sub-trochanteric fracture secondary to osteoporosis. Contact between the native bone and bone graft was observed. Marrow elements and repair tissue were visible within the pores in the graft (Figure 2a).

Case 2 (Male, age 67, ARCO IIIC, revised after 82 days): Two wires were broken but retained within the braided structure. A radiolucent gap caused by the presence of fibrous tissue between the graft mixture and native bone was evident suggesting that the implant was unable to prevent progression in this case.

Case 3 (Female, age 70, ARCO IIC, revised after 482 days): The cavity penetrated the subchondral surface; at revision the implant was found to have breached the articular cartilage. There was partial separation of the proximal osteonecrotic fragment and no evidence of graft revascularisation or remodelling within the implant.

Case 4 (Male, age 42, ARCO IIC, revised after 469 days): There was no indication of bone graft re-integration. Collapse of the necrotic bone and deformation of the implant was diagnosed from 1 year follow-up x-rays.

Bone ingrowth fixation of large diameter, beaded cobalt chromium cups is generally considered to be reliable but this is typically judged radiographically. To date, implant retrieval data of attached bone has been limited. This study evaluated correlations between the pre-revision radiographic appearance and the measured amount of bone attachment on one design of porous coated cup.

The histopathology of periprosthetic tissues has been important to understanding the relationship between wear debris and arthroplasty outcome. In a landmark 1977paper, Willert and Semlitsch (1) used a semiquantitative rating to show that tissue reactions largely reflected the extent of particulate debris. Notably, small amounts of debris, including metal, could be eliminated without “overstraining the tissues” but excess debris led to deleterious changes. Currently, a plethora of terms is used to describe tissues from metal-on-metal (M-M) hips and corroded modular connections. We reviewed the evaluation and reporting of local tissue reactions over time, and asked if a dose response has been found between metal and tissue features, and how the use of more standardized terms and quantitative methodologies could reduce the current confusion in terminology.

Purpose and Background:

To identify treatment effect modifiers within the STarT Back Trial which demonstrated prognostic stratified care was effective in comparison to standard care for patients with low back pain.

Background and purpose

To identify methods used to measure free living sedentary behaviour in people with back pain and review the validity and reliability of identified measures.

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.

This abstract is currently withdrawn to allow an independent review of findings to take place.

This protocol describes a pragmatic multicentre randomised controlled trial (RCT) to assess the clinical and cost effectiveness of arthroscopic and open surgery in the management of rotator cuff tears. This trial began in 2007 and was modified in 2010, with the removal of a non-operative arm due to high rates of early crossover to surgery.

Cite this article: Bone Joint Res 2014;3:155–60.

Objective

Mortality rates reported by the National Joint Registry for England and Wales (NJR) were higher following cemented total knee replacement (TKR) compared with uncemented procedures. The aim of this study is to examine and compare the effects of cemented and uncemented TKR on the activation of selected markers of inflammation, endothelium, and coagulation, and on the activation of selected cytokines involved in the various aspects of the systemic response following surgery.

This purpose of this study was to investigate whether prophylactic pinning of the contralateral hip in unilateral slipped upper femoral epiphysis affects subsequent femoral morphology.

To determine the effect of prophylactic pinning on growth we compared contralateral hip radiographs of 24 proximal femora prophylactically pinned with 26 cases observed, in a cohort of patients with unilateral SUFE. Validated measurements were used to determine hip morphology; the articulo-trochanteric distance (ATD) and the ratio of the trochanteric-trochanteric distance (TTD) to articulo-trochanteric distance (TTD:ATD) in addition to direct measurement of the femoral neck length. Post-operative radiographs were compared to radiographs taken at a 12–84 months follow-up.

Comparing pinned and unpinned hips the neck length was shorter (mean 5.1 mm vs 11.1 mm) and the ATD was lower (p=0.048). The difference between initial and final radiograph TTD:ATD ratio for each case was calculated. The average was 0.63 in the prophylactically pinned group and 0.25 in the unpinned group (p=0.07).

When hips of the same patient were compared on final radiographs, there was a smaller difference in TTD:ATD between the two sides when the patient had been prophylactically pinned (0.7) as opposed to observed (1.47). This was not statistically significant (p=0.14).

Universal prophylactic pinning of the contralateral hip in slipped upper femoral epiphysis is controversial and alteration of the proximal femoral morphology is one reason for this.

Our results show that prophylactic pinning does not stop growth but does alter subsequent proximal femoral morphology by causing a degree of coxa vara and breva. Some loss of growth in the prophylactically pinned hip contributes to reduction in leg length inequality at skeletal maturity which is advantageous.

No iatrogenic complications were observed with single cannulated screw fixation. Prophylactic pinning prevents the potential catastrophe of a subsequent slip, is safe and the effect on growth is, if anything, beneficial.

Level of evidence: III

Objectives

To investigate psychosocial and biomedical outcomes following total hip replacement (THR) and to identify predictors of recovery from THR.

Objectives

We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip.

Adequate range of knee motion is critical for successful total knee arthroplasty. While aggressive physical therapy is an important component, manipulation may be a necessary supplement. There seems to be a lack of consensus with variable practices existing in managing stiff postoperative knees following arthroplasty. Hence we did a postal questionnaire survey to determine the current practice and trend among knee surgeons throughout the United Kingdom.

A postal questionnaire was sent out to 100 knee surgeons registered with British Association of Knee Surgeons ensuring that the whole of United Kingdom was well represented. The questions among others included whether the surgeon used Manipulation Under Anaesthaesia (MUA) as an option for stiff postoperative knees; timing of MUA; use of Continuous Passive Motion (CPM) post-manipulation.

We received 82 responses. 46.3% of the respondents performed MUA routinely, 42.6% sometimes, and 10.9% never. Majority (71.2%) performed MUA within 3 months of the index procedure. 67.5% routinely used CPM post-manipulation while 7.3% of the respondents applied splints or serial cast post MUA. 41.5% of the surgeons routinely used Patient Controlled Analgaesia +/− Regional blocks. Majority (54.8%) never performed open/arthroscopic debridement of fibrous tissue for adhesiolysis.

Knee manipulation requires an additional anaesthetic and may result in complications such as: supracondylar femur fractures, wound dehiscence, patellar tendon avulsions, haemarthrosis, and heterotopic ossification. Moreover studies have shown that manipulation while being an important therapeutic adjunct does not increase the ultimate flexion that can be achieved which is determined by more dominant factors such as preoperative flexion and diagnosis. Manipulation should be reserved for the patient who has difficult and painful flexion in the early postoperative period.

There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery.

There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs.

In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.

Cite this article: Bone Joint J 2013;95-B:486–92.

Background

A wide array of measures has been developed to assess the role of psychological factors in the development and persistence of pain. Yet there is likely to be considerable conceptual overlap between such measures, and consequently a lack of clarity about the importance of psychological factors.

Background

People with back pain often experience long-term pain with recurrences and fluctuations. However, few studies have considered which factors predict long-term outcomes.

It has been suggested that metal ion levels are indicative of in vivo bearing performance of metal-on-metal hip replacements. A cobalt or Chromium level of 7μg/L or higher is proposed to be indicative of a bearing malfunction and the need for clinical intervention. Component design, size, acetabular orientation, patient gender and activity level have been suggested as factors leading to accelerated wear and elevated metal ions. The contact patch to rim (CPR) distance is a calculation that describes the distance from the point where a theoretical joint reaction force intersects the cup to the acetabular rim for a patient in standing position, dependent on the coverage, size, and orientation of the acetabular component. It has been suggested that CPR distance determines the hip joint susceptibility to edge loading, and the risk for increased wear and high ion levels (Langton et al JBJS Br 91: 2009). This study examined the effects of patient activity, gender, and CPR distance on serum metal ion concentrations in a series of patients treated with one type of metal on metal hip resurfacing arthroplasty (MMHRA) performed by one surgeon.

182 patients (73 females and 109 males)with a unilateral Conserve Plus (WMT, TN USA) MMHRA and had who had provided blood for metal ion analysis data from December 2000 to June 2011 were retrospectively studied. Only measurements made more than 12 months after surgery were included in order to exclude hips that had yet to reach steady-state wear. For patients with multiple draws, the most recent qualifying draw was used. Activity level was assessed by the UCLA activity score. The mean age was 51.5 years (20.0 to 77.5 years). The mean follow-up time for the last blood draw was 70 months (range, 12 to 165). Serum cobalt (CoS) and chromium (CrS) levels were analyzed using inductively coupled plasma mass spectrometry in a specialized trace element lab. Using acetabular abduction and anteversion measured by EBRA, component size, and reported coverage angle of the acetabular component, the CPR distance was calculated as previously described. Multiple logistic regression was performed to identify significant relationships between high metal ion levels (7 μg/L or greater) and gender, activity and CPR distance.

The median CoS level for the entire cohort was 1.13 μg/L (range, 0.15 to 175.30), and the median CrS level was 1.49 μg/L (range, 0.06 to 88.70). The average CPR distance was 13.8 mm (range, 3.2 to 22.1). There was a significant association between low CPR values and CoS and CrS. There was a 37-fold increase in the risk of CoS >7μg/L (p=0.005) and 11-fold increase in the risk of CrS > 7μg/L (p=0.003) when CPR distance was 10 mm or less. No associations were shown for gender and UCLA activity scores.

CPR distance was found to be a reliable predictor of ion levels > 7μg/L and appears to be a useful indicator to evaluate the multi-factorial process of edge-loading and wear. Patients with a low CPR distance should be monitored for increased metal ion levels.

The Conserve® Plus (Wright Medical Technology Inc., Arlington, TN) was introduced clinically in the United States in 1996. A study of the serum cobalt and chromium ion levels was started in 2000 in our center to monitor the metal ion levels over time as part of an FDA clinical trial.

Thirteen male and five female patients received this resurfacing for idiopathic osteoarthritis (14), post-traumatic degenerative changes (3) or developmental dysplasia (1). Fourteen received a unilateral implant but four subsequently received a contralateral device from 52 to 86 months post-op. Four patients had bilateral resurfacings done in a one-stage procedure. All surgeries were performed by the senior author. None of these patients had known exposure to cobalt or chromium, kidney disease or other metal implants elsewhere in their bodies. Each prospectively provided blood samples and then yearly thereafter to measure cobalt and chromium levels for up to 11 years. Metal levels were measured using atomic absorption spectrophotometry and inductively coupled plasma mass spectrometry by a specialized trace element analysis laboratory. Acetabular component position was evaluated using Einzel-Bild-Röentgen-Analysis (EBRA) software. Contact patch to rim (CPR) distance was computed as described by Langton et al JBJS Br 91: 2009. A mixed model linear regression analysis was performed to evaluate long term trends, and multivariate analysis was performed to examine effects of implant and patient covariates on the metal ion levels.

One bilateral patient underwent revision for femoral loosening, all other patients were clinically well-functioning at the time of last follow-up (ave 89 mos). The median pre-operative Co was below the detection limit (d.l) of 0.3μg/L and the median pre-operative Cr was 0.069μg/L (d.l. 03μg/L). Metal levels increased within the first year then decreased and stabilized (fig 1). For unilaterals over all time intervals, the median Co was 1.06 μg/L, while the median Cr was 1.58 μg/L. For bilaterals, the mean post-operative Co was 2.80 μg/L, while the mean Cr was 5.80 μg/L. Generally, Cr levels were higher at all time points than Co. Bilateral patients had Co values 1.96 times greater on average than the unilateral patients (p<0.001). None of the possible covariates studied (femoral size, cup abduction angle, cup anteversion, CPR distance, activity, BMI and testing method) were related to the assay values.

The results of this study have shown that serum metal levels in well functioning implants can be low and do not increase over time. These are among the lowest levels reported for resurfacing devices and comparable to levels reported for well functioning small diameter metal-on-metal total hips. The study is limited due to the relatively small sample size and limited range of values for the covariates studied. However, it included patients who were active, female or bilateral and we collected ion levels up to 11 years. We now recommend that patients who have well-oriented Conserve Plus components with stable radiographic interfaces and no incidences of unexplained pain or hip noises be scheduled for follow-up every 2–3 years, rather than annually.

In patients with conventional metal-on-Polyethylene (MoP) hip replacements, osteolysis can occur in response to wear debris. During revision hip surgery, surgeons usually remove the source of osteolysis (polyethylene) but cannot always remove all of the inflammatory granulomatous tissues in the joint. We used a human/rat xenograft model to evaluate the effects of polyethylene granuloma tissues on bone healing. Human osteoarthritic and periprosthetic tissues collected during primary and revision hip arthroplasty surgeries were transplanted into the distal femora of athymic (nude) rats. The tissues were assessed before and after implantation and the bone response to the tissues was evaluated after 1 week and 3 weeks using micro-computed tomography, histology, and immunohistochemistry. After 3 weeks, the majority (70%) of defects filled with osteoarthritic tissues healed, while only 21% of defects with polyethylene granuloma tissues healed. Polyethylene granuloma tissues in trabecular bone defects inhibited bone healing. Surgeons should remove polyethylene granuloma tissues during revision surgery when possible, since these tissues may slow bone healing around a newly implanted prosthesis. This model provides a method for delivering clinically relevant sized particles into an in vivo model for investigation.

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.

Background

Pseudotumours have been associated with metal-on-metal (MoM) hip replacements. We define it as a solid mass which may have cystic components that is neither neoplastic nor infectious in aetiology. The cause of a pseudotumour is not fully understood but could be due to excessive wear, metal hypersensitivity or due to an as-yet unknown cause.

Introduction

Children with early-onset scoliosis (EOS) with rib hump chest-wall distortion or fused/absent ribs have thoracic insufficiency syndrome (TIS). Commonly, respiration is adversely affected by loss of lung volume from chest-wall constriction and clinical loss of active rib cage expansion. The dynamic thoracic components of diaphragm or rib cage lung expansion during respiration is poorly characterised by radiograph or CT scan. Pulmonary function tests indicate only hemithorax performance. Dynamic lung MRI, however, can visualise both chest-wall and diaphragm motion, allowing assessment of each individual hemithorax performance, so that a dynamic classification system of the thoracic function can be developed.

The aim of this study was to examine the effects of cement in total knee arthroplasty on markers of inflammation and endothelial dysfunction, as surrogate markers for enhanced risk of vascular disease or precipitation of acute vascular events post-operatively.

A total of 36 patients were recruited, with 18 in each of the cemented and uncemented groups. Both groups were matched for age, sex and body mass index.

Venous blood samples were taken pre-operatively, day 1 and day 7 post-operatively. Serum levels of interleukin 6 (IL6), tumour necrosis factor (TNF□?, e-selectin, Von willebrand factor (vWF), tissue plasminogen activator (tPA) and soluble CD40 ligand were analysed. Also, real time analysis of the expression of CD40 and CD14/CD42a aggregates on monocytes was carried out using flow cytometry. Patients were excluded from the study if there were signs of either superficial or deep infection.

The only variable to demonstrate a significant difference between the two groups was the CD1442a count. There was a significant difference in the first 24 hours (p=0.00) and from day 1 to day 7 (p=0.02)

Our study suggests that the use of bone cement causes a significant rise in CD1442a count which has been linked to atherothrombosis and acute coronary syndromes. These changes may explain the increased incidence of venous thrombosis and thromboembolism post-operatively. However more research required in this field to delineate the exact pathways involved.

Increasingly, high flexion components have been touted by the industrial manufacturers of them as the implants of choice for routine total knee replacement (TKR). An acceptable flexion arc is obtainable in most patients through various intra-operative techniques; however, the importance of obtaining high flexion—which we define as greater than 120 degrees—is unclear.

In our pilot study, a review was undertaken involving 60 of the senior authors patients who attained greater than 120 degrees of flexion after receiving an implant said to be high flexion based on the presence of both a rotating platform as well as a conforming cam-and-post third condylar space.

Despite the achievement of both high flexion and impressive patient satisfaction, no functional benefits were observed—an observation that is supported in the current literature. We will explore possible reasons for this discord and note that most patients did not express the desire to regularly perform high flexion activities such as kneeling, squatting and stooping on a daily basis. Our results and evaluation of the literature lead us to question the importance placed upon the achievement of the maximum possible post-operative flexion arc as well as the importance placed in the ability to perform high flexion activities.

This, in turn, calls into question the validity of many of the currently accepted outcomes measures used to post-operatively evaluate total knee replacements.

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.

Thromboprophylaxis for venous thromboembolism (VTE) after elective arthroplasty remains controversial. Previous surveys have shown considerable variation amongst orthopaedic surgeons, and the topic is still being debated. Chest physicians recently advocated that randomised data demonstrating a risk reduction with long- established thromboprophylaxis have been ignored by orthopaedic surgeons. We present the current thromboprophylaxis practice amongst AOA members performing elective hip and knee replacements and discuss its rationale.

All orthopaedic surgeons in the AOA were asked to complete a one page postal questionnaire asking for information regarding: whether they performed elective hip or knee arthroplasty, which methods of mechanical and/or chemical prophylaxis were routinely used, the time frame in ceasing thromboprophylaxis, the motive in using thromboprophylaxis, and whether thromboprophylaxis guidelines released by the AOA or RACS would be helpful in their orthopaedic practice.

Responses from the survery are currently being collected and analysed. These results will be ready for presentation at the AOA conference.

The results of the survey will be presented in addition to a discussion of the rationale behind current use of post-operative thromboprophylaxis for elective hip and knee arthroplasty and a need for clinical guidelines.

Aim

To examine the effects of total knee arthroplasty on markers of inflammation and endothelial dysfunction, as surrogate markers for enhanced risk of vascular disease or precipitation of acute vascular events post-operatively.

Aim

To compare a variety of commercially available bone graft substitutes (BGS) in terms of promoting adherence, proliferation and differentiation of osteoprogenitor cells.

Prevalence of rotator cuff tears increases with advancing age (Ellman et al). In spite of proximal humeral fractures being common in the elderly, the influence of a coexistent rotator cuff tear on outcome has, to our knowledge, not been previously investigated. This study prospectively assessed whether the presence of a rotator cuff tear in association with a proximal humeral fracture influences functional prognosis.

85 patients treated conservatively for proximal humeral fractures were evaluated prospectively with Ultrasonography to determine the status of the rotator cuff. Every patient was managed by immobilisation of the arm in a sling for two weeks followed by a course of physiotherapy based on the Neer regime. Functional outcome was measured using the Constant shoulder score and the Oxford shoulder score, at 3-months and 12-months post injury.

Sixty-six of the 85 patients were female. The fractures were equally distributed for hand dominance. There were 27 patients with an undisplaced fracture, 34 patients with Neer's Type II fracture and 24 patients with Neer's Type III and IV fracture. There were 43 patients with full thickness cuff tears and 42 patients with no cuff tear or a partial thickness tear. Full thickness cuff tears were much more frequent in the over 60 year age group, which is consistent with the known increased incidence of cuff tears with increasing age.

The outcome scores at 3 and 12 months showed no statistically significant difference for either the Constant score or the Oxford score with regards to cuff integrity. Analysis of these scores showed no correlation between presence or absence of a full thickness cuff tear and shoulder function

The results of this study indicate that rotator cuff integrity is not a predictor of shoulder function at 12 months following proximal humeral fracture, as measured by outcome scores. This suggests that there is therefore no clinical indication for routine imaging of the rotator cuff in patients for whom conservative management is the preferred treatment option.

We report a case of a male patient presenting with bilateral painful but apparently well-positioned and -fixed large-diameter metal-on-metal hip replacements four years post-operatively. Multiple imaging modes revealed a thick-walled, cystic expansile mass in communication with the hip joint (a pseudotumour). Implant retrieval analysis and tissue culture eliminated high bearing wear or infection as causes for the soft-tissue reaction, but noted marked corrosion of the modular neck taper adaptor and corrosion products in the tissues. Therefore, we believe corrosion products from the taper caused by mismatch of the implant components led to pseudotumour formation requiring revision.

Clinical proteomics is an exciting new sub-discipline of proteomics that involves the application of proteomic technologies at the bedside to identify new biomarkers, associated with specific diseases. In this study to compare serum protein profiles between identical age-matched groups of fracture and non-fracture controls, we looked at the initial proteomic profile of 10 patients who had fractures and compared them to age-matched controls to see if there was any specific difference indicative of fracture.

Background

Social context may be important in chronic pain. One focus is reactions to pain between persons with LBP and their partners. Researchers have investigated partner reactions and found influences on pain levels and psychological outcomes, but little is known about factors underpinning these reactions.

There have been many reports of metal ion levels measured in the bloodstream of patients after metal-on-metal hip replacement, and it is generally accepted that levels of cobalt (Co) and chromium (Cr) are elevated after these types of devices are implanted. However, it is not clear how to interpret these elevated levels; in particular what are the acceptable levels and what levels indicate that close monitoring of the patient is needed. Our aim was to establish the differences in metal ion levels between well functioning patients and those with clinical problems.

We measured serum Co and Cr levels (microgram’s per litre or μg/l) using inductively coupled plasma mass spectrometry with a well established collection protocol of all patients attending follow-up clinics. Our inclusion criteria for this study were all patients unilaterally implanted with a metal-on-metal hip resurfacing with no other metallic implant; patients were categorized as either A. Well Functioning or B. Clinically Problematic (pain, reduced function, reduced ROM, negative x-ray findings) and differences in ion levels between these two groups were examined. Well functioning patient data was only included if measurements were made more than 12 months post-operatively to avoid run-in wear levels. Abduction angle was also measured from x-rays of the pelvis, and the frontal plane coverage arc of each implanted cup calculated (De Haan JBJS[Br] 2008;90(10):1291–7). There were a total of 519 patients, with 358 in Group A and 161 in Group B; patients had a variety of devices with Birmingham Hip Resurfacing (64%) and Conserve Plus (29%) being the most commonly implanted. To establish a guideline upper ion level value for well functioning implants the upper 75th percentile values for Co and Cr levels for Group A patients having 15 mm or more coverage arc were calculated. The risk of having clinical problems was calculated as function of metal ion levels higher or lower than these upper limits.

The ion levels were significantly (Mann Whitney U p< 0.001) higher in Group B (mean [95% confidence intervals], Co 10.2 μg/l [5.9 to 14.5], Cr 10.3 μg/l [6.7 to 14.0]) compared to Group A (Co 2.3 μg/l [1.7 to 2.4], Cr 2.8 μg/l [2.3 to 3.4]). The well functioning upper limit for Co was 4.1 μg/l and for Cr was 5.2 μg/l. Metal ion levels greater than these upper limits were significantly (Chi-square p< 0.001) associated with the presence of clinical problems. The odds ratio for Co greater than 4.1 μg/l was 11.2 [95%CI 5.7 to 22.3] and that for Cr greater than 5.2 μg/l was 4.3 [95%CI 2.6 to 7.0].

There were significantly higher metal ion levels measured in patients with clinical problems after metal-on-metal hip resurfacing than those with well functioning hips. We have proposed upper acceptable limits for Co (4.1 μg/l) and Cr (5.2 μg/l) serum levels. Cobalt levels appear to be more reliable in predicting risk of clinical problems; levels greater than our proposed upper limit have 11 times the odds of developing clinical problems and patients with such levels should be followed closely.

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.

Aim: While ankle fractures are not thought of as osteoporotic fractures, poor bone quality presents difficulties in fracture fixation of the distal fibula. We measured the relation between bone density of the distal fibula and the insertional and stripping torques of screws used for fibular plating using two different plate configurations.

Methods: Ten paired fresh cadaveric ankles (average age: 81.7 years) were used for the study. Computed tomography scanning with phantoms of known density was used to determine the bone density along the distal fibula. A standard small fragment seven-hole one-third tubular plate was applied to the lateral surface of the fibula, with three proximal bicortical cortical screws and two distal unicortical cancellous screws. A posterior plate in which all five screws were cortical and achieved bi-cortical purchase was subsequently applied to the same bones such that the screw holes did not overlap. A torque sensor was used to measure the torque of each screw during insertion (Ti) and then stripping (Ts).

Results: Mean bone density of the distal fibula is significantly less than in the shaft (p< 0.01). There was a moderate positive correlation between torque and bone density for the lateral plates (r2=0.6 for Ti and r2=0.7 for Ts), and a weak correlation for the posterior plates (r2=0.4 for Ti and Ts). For the proximal three screws, there was no significant difference in average Ti and Ts between lateral and posterior plates. For the distal two screws, posterior plates had significantly higher values for both Ti and Ts than the lateral plates (p< 0.01).

Conclusions: The insertion and stripping torques of the screws in the distal fibula were significantly higher and less dependent on bone density with a posterior plate than with a lateral plate.

Ion levels in the serum and urine of patients with metal-on-metal hip resurfacing implants can provide a means to monitor bearing wear. This presentation will discuss the current results, now out to 5 years for the Conserve Plus resurfacing. In particular, the effect of bilateral implantation on ion levels was examined

Forty-eight patients were studied. Forty-three of these cases were initially implanted with a unilateral resurfacing. Nine of these cases subsequently were implanted with a resurfacing implant on the contra-lateral side 4 to 48 months following the first implantation (staged implantations). Five cases had bilateral resurfacings done simultaneously. All surgeries were done in one institution by a single surgeon. Serum and urine samples were collected pre-operatively, and at 4 months, 12 months and annually thereafter. The samples were analysed for cobalt and chromium using atomic absorption spectrometry with a detection limit of 0.3 to 0.03ng/ml respectively. The data were compared between the groups and also correlated with UCLA activity scores, cup angle, BMI and component size.

All patients showed a rise in ions following implantation. The simultaneous bilateral levels were higher at all time periods compared with the staged bilaterals monitored at the same time point for the second hip, for example cobalt serum at 12 month uni = 2.24, simultaneous bilat = 2.53, staged bilat = 2.05ng/ml, and at 4 years uni = 1.20, simultaneous bilat = 2.93, staged bilat = 2.27ng/ml. There was no correlation between ion levels and UCLA activity score, gender, component size or cup angle (but only 4 hips had cups > 55 degrees).

Bilateral metal-on-metal hip resurfacings performed simultaneously resulted in higher levels of metal ions, particularly chromium, compared to staged implantations monitored at the same time periods. With the exception of a small number of outliers, the levels in this group of hip resurfacings were within the range of metal levels reported for other metal-on-metal total hips.

We report the consensus of surgical opinions of an international faculty of expert metal-on-metal hip resurfacing surgeons, with a combined experience of over 18 000 cases, covering required experience, indications, surgical technique, rehabilitation and the management of problematic cases.

Introduction: The Implant Retrieval Laboratory at Orthopaedic Hospital has been collecting and studying retrieved metal-on-metal total hip replacements for over 15 years. The analysis of these implants has provided important insights into their clinical wear performance and the biocompatibility of the wear products. In addition to stem-type implants of first generation (McKee-Farrar) and modern generation (Metasul) implants with metal-on-metal bearings, the lab has performed analysis on over 200 failed metal-on-metal hip resurfacing devices to determine factors relevant to their failure. The primary goal of these analyses was to understand the failure mechanisms and the ways in which failures may be preventable through optimized patient selection and surgical techniques. Lessons learned from these implants include: well-manufactured and well-placed metal-onmetal implants have very low wear rates; conversely poorly manufactured or badly placed implants can have high wear rates; hip resurfacing failures are most often the result of bad bone quality, bad surgical technique or both. Perhaps the most significant finding is that despite the presence of an implant producing wear debris and altering biomechanical stresses, the majority of hip joints heal, adapt and provide a clinically successful outcome.

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.

Purpose: To compare the reoperation rates of three commonly used forms of fixation for distal femur fractures.

Method: 89 patients treated between 2002 and 2006 were retrospectively reviewed (mean follow up 28 months).. 40 fractures were treated with an intramedullary nail (IMN), 34 with the LISS internal fixator and 16 with a DCS construct. Patients were reviewed clinically and radiographically. The primary treatment outcome was the rate of secondary surgical intervention; secondary outcomes included radiographic alignment and clinical outcome measures (LEM and SF-36).

Results: Reoperation: Reoperation rate for the DCS group was 12.5%, compared to 17.5 % in the IMN group and 44 % in the LISS group. Failure rates were the same when only AO type C fractures were considered. Most concerning in the LISS group was the rate of failure in distal short oblique type A fractures, in which catastrophic failure was observed in 4 of 9 patients. Alignment was similar comparing all three groups; the average radiographic distal femoral articular angle (DFAA) of was 10 degrees valgus in the DCS group, compared to 8 degrees in the IMN group and the LISS patients.

Conclusion: Reoperation rate was highest in this study when the LISS fixator was used for distal short oblique fractures of the femur. These fractures may benefit from fixation which achieves direct interfragmentary compression, such as an intramedullary device or compression plating.

Femoral neck fracture is a common short-term hip resurfacing failure mode, but later term fractures are starting to be reported. The fracture pattern may indicate whether etiology is primarily mechanical or biological¹. This study evaluated fracture patterns in conjunction with histology to determine etiology in a varied group of hip resurfacings.

Central 3mm thick coronal slices were cut from each of 50 cemented and 2 cementless fractured femoral components (27 males, 25 females). Fracture patterns were grouped as: “edge to edge”, “inside head”, “outside” and “edge to outside”¹. Sections were decalcified and processed for routine histology to examine viability and remodelling. Bone viability was judged on the presence of osteocyte nuclei. Components were judged to be unseated if the cement mantle was more than twice the manufacturers recommended thickness. Histological and clinical data were correlated with fracture pattern.

Overall average time to fracture was 6 months (1–85 months). There were 25 “edge to edge”, 12 “inside head”, 4 “outside” and 11 “edge to outside” fractures, which occurred after a median of 2.0, 13, 1.5, and 2.0 months respectively. The majority of the heads were viable, and the fractures occurred through a region of healing bone involving one or both edges. Fifteen heads with a substantial proximal avascular segment fractured at the interface between necrotic and viable bone, typically inside the component. Eleven implants (21%) were considered unseated. All 4 “outside” fractures were found to be unseated. All “inside head” fractures were seated, but 83% (10/12) of them were found to be avascular. The latest failure (85 months) occurred in association with wear-induced osteolysis. Both cementless components fractured early with an “edge to outside” pattern and were found to be substantially avascular.

Avascular heads failed from one month to four years, usually inside the component. Viable heads tended to fracture early through an area of healing bone at or below the rim. Most fractures were technical failure-sand might be avoided with better patient selection and surgical technique.

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.

Introduction: Management of Ficat stage III and IV hip osteonecrosis remains a formidable challenge in regards to long term care. We report a case of a hemiresurfacing arthroplasty lasting 23 years in a patient who received the implant for osteonecrosis associated with corticosteroid use following kidney transplantation. In 1981, a moderately obese, 27-year-old man presented with bilateral osteonecrotic collapse of the femoral heads secondary to heavy immunosuppressive corticosteroid therapy associated with a kidney transplant. The patient had suffered a loss of both kidneys after a bout of severe nephritis that resulted in replacement with a cadaver kidney in 1979. A cemented THARIES (total hip articular replacement with internal eccentric shells) metal-on-polyethylene resurfacing (Zimmer, Warsaw, Indiana) was implanted in the right hip in 1981. At 3 years post-operatively, the patient complained of acute, exacerbated pain in his right hip. The THARIES components were removed for acetabular and femoral loosening and replaced with a total hip replacement.

Surgery: The acetabular cartilage of the other hip was rated intraoperatively as Grade III (no or minimal acetabular cartilage involvement), and was deemed suitable for hemiresurfacing. A 50 millimeter custom cemented titanium shell (Zimmer, Warsaw, Indiana) was implanted using a lateral incision and a trans-trochanteric approach. The patient continued to be assessed by the surgeon on a regular basis, and returned to an active lifestyle while his kidney function continued to be regulated with corticosteroids and imoran. In 1989, eight years following hemiresurfacing, the left hip radiographs showed a reduced joint space, with further new bone in the acetabular fossa, and the patient continued to do well. UCLA hip scores were 9, 9, 10, and 7 for pain, walking, function and activity, respectively compared with 6, 6, 4, and 4 preoperatively. Radiographs taken at 18 years post-operatively showed further narrowing of the joint space, but the patient continued to be asymptomatic. At the 22-year clinic visit, the patient, now 50 years old, complained of slight groin pain, and some minor limitation in his activities, but was still able to walk without any method of support, and able to participate in recreational exercise including swimming, baseball, and weight lifting. The resurfacing hip was revised to a total hip at 23 years post-op and the specimen was submitted for implant retrieval analysis. This involved sectioning the component into three, 3-millimeter thick coronal slices, which were decalcified and routinely embedded in paraffin.

Results: Hematoxylin and Eosin stained sections showed that the bone within the head was osteopenic but viable with areas of healed old necrotic segments of trabeculae which were surrounded by appositional new bone with some focal areas of recently formed woven bone. A fibrous membrane ranging from a few microns to 1.8 millimeters in thickness was present along most of the cement interface and this contained scattered particle-filled macrophages. There were occasional osteoclastic resorption fronts of bone against this membrane, but osteoblasts were also occasionally seen lining the non-membrane surface. The resurfaced head and neck showed remarkable preservation of bone stock. Although there was minimal cement penetration into the bone, either because of lack of initial penetration or from fragmentation of the cement over the years, the component was functionally well fixed. The bone was viable and there were minimal effects of the small amount of titanium metal debris.

Discussion: Studies report osteonecrosis of the femoral head developing in approximately 11% of hips and 20% of patients receiving organ transplants and for young patients conservative methods need to be pursued. While the best choice of treatment for osteonecrosis is not universally agreed upon, the options are limited once collapse of the femoral head has occurred. Treatment for these patients should be based on the progression of the disease, the age of the patient, and the patient’s long-term needs. This patient had a hemiresurfacing and a metal-on-polyethylene resurfacing; the latter succumbed to polyethylene induced osteolysis, but the hemiresurfacing provided good clinical function in a young, normally active patient for 23 years. While it is recognized that hemiresurfacing is not suitable for every patient with osteonecrosis, it remains a treatment option for some patients.

Introduction: A major concern with cemented hip resurfacing arthroplasty (HRA) femoral components is the thermal damage to femoral head during cement curing; this maybe linked to fracture (reported incidence ~2%) and early failure. We investigated the effect of a modifid surgical technique using pulse lavage, lesser trochanter suction and early reduction on the maximum temperature recorded in the femoral head during HRA, compared to manual lavage and reduction after cement curing.

Methods: Patients undergoing total hip replacement (THR) were given a dummy HRA procedure, during which a temperature probe was inserted into the femoral head and the measuring tip placed close to the reamed surface; the position of the probe was confirmed by inter-operative xray. Four subjects received a dummy HRA femoral component using manual lavage and Simplex cement. The implanted femur was kept dislocated until the cement cured. The implanted heads were then removed and sectioned to locate the temperature probes, the THR surgery was then performed. Five patients receiving a definitive HRA were also measured; for these subjects suction on the lesser trochanter was used, pulse lavage given for 30 seconds prior to cementing with Simplex, and pulse lavage of the femoral head for 2 minutes, applied 1 minute after cementing the femoral component. The implanted joint was then immediately reduced and a further two minutes of pulse lavage applied to the reduced joint. Temperatures were recorded until the cement finally cured. In every case the cement was hand mixed for 1 minute and the component implanted at 2 minutes 30 seconds after mixing began.

Results: Sectioning showed that probe tips were < 0.5mm from cement mantle. The maximum temperature recorded in the femoral head was significantly (p=0.014) greater for the manual technique, median value of 47.2°C (37.0 to 67.9°C), than for the pulse lavage technique, median value of 32.7°C (31.7 to 35.6°C).

Discussion: The results show that excessive bone temperatures can occur during hip resurfacing. Temperatures above 45°C kill bone cells, the manual technique may lead to substantial thermal necrosis. Technique modification, with the use of suction on the lesser trochanter, generous use of pulse-lavage and joint reduction prior to cement curing, significantly reduced the temperatures recorded. With the modified technique, the maximum temperatures were well below the threshold of thermal damage. This modified technique is recommended as the potential for thermal bone necrosis is significantly reduced.

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.

We examined the relationships between the serum levels of chromium and cobalt ions and the inclination angle of the acetabular component and the level of activity in 214 patients implanted with a metal-on-metal resurfacing hip replacement. Each patient had a single resurfacing and no other metal in their body. All serum measurements were performed at a minimum of one year after operation. The inclination of the acetabular component was considered to be steep if the abduction angle was greater than 55°.

There were significantly higher levels of metal ions in patients with steeply-inclined components (p = 0.002 for chromium, p = 0.003 for cobalt), but no correlation was found between the level of activity and the concentration of metal ions. A highly significant (p < 0.001) correlation with the arc of cover was found. Arcs of cover of less than 10 mm were correlated with a greater risk of high concentrations of serum metal ions. The arc of coverage was also related to the design of the component and to size as well as to the abduction angle of the acetabular component. Steeply-inclined acetabular components, with abduction angles greater than 55°, combined with a small size of component are likely to give rise to higher serum levels of cobalt and chromium ions. This is probably due to a greater risk of edge-loading.

We have reviewed 42 patients who had revision of metal-on-metal resurfacing procedures, mostly because of problems with the acetabular component. The revisions were carried out a mean of 26.2 months (1 to 76) after the initial operation and most of the patients (30) were female.

Malpositioning of the acetabular component resulted in 27 revisions, mostly because of excessive abduction (mean 69.9°; 56° to 98°) or insufficient or excessive anteversion. Seven patients had more than one reason for revision. The mean increase in the diameter of the component was 1.8 mm (0 to 4) when exchange was needed.

Malpositioning of the components was associated with metallosis and a high level of serum ions. The results of revision of the femoral component to a component with a modular head were excellent, but four patients had dislocation after revision and four required a further revision.

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: Hip resurfacing has been increasingly used procedure for physiologically young and active patients. Wear properties of the implants are considered to be excellent. We present a case of tumor like swelling of the thigh following metal on metal hip resurfacing.

Case report: 56 year old lady underwent metal on metal hip resurfacing for idiopathic osteoarthritis of right hip. Implant size: 38 mm head with 44 mm cup.

After 18 months of successful surgery she presented with short duration (2 weeks) history of thigh swelling with pain and stiffness in hip and knee. Clinically gross circumferential swelling of right thigh from inguinal ligament to the knee joint. She had increased serum cobalt chromium levels. Aspiration of hip revealed high levels of cobalt and chromium. Biopsy and intra operative samples at revision revealed “no infection or tumor but non specific inflammatory reaction.”

The patient underwent revision surgery to ceramic-plastic bearing.(THR).

12 months post operative, the swelling has reduced with painless mobile hip and knee joints.

Discussion: The metal on metal hip resurfacing could have produced high metal ion wear reaction leading to swelling. Which could be because of small diameter prosthesis with valgus position of femoral component with open cup angle of 49 degrees.