Background

Endoprosthetic reconstruction is an established method of treatment for primary bone tumours in children. Traditionally these were implanted with cemented intramedullary fixation. Hydroxyapatite collars at the shoulder of the implant are now standard on all extremity endoprostheses, but older cases were implanted without collars. Uncemented intramedullary fixation with hydroxyapatite collars has also been used in an attempt to reduce the incidence of problems such as aseptic loosening. Currently there are various indications that dictate which method is used.

Autologous chondrocyte implantation (ACII) has been shown to have favourable results in the treatment of symptomatic chondral and osteochondral lesions. However, there are few reports on the outcomes of this technique in adolescents.

The aim was to assess functional outcome and pain relief in adolescents undergoing autologous chondrocyte implantation (ACI).

Thirty-one adolescent patients undergoing ACI or Matrix-assisted chondrocyte implantation (MACI) were identified from a larger prospective study. Mean age was 16.3 years (range 14 – 18) with a mean follow-up of 66.3 months (12–126 months).

There were 22 males and nine females. All patients were symptomatic; 30 had isolated lesions and one had multiple lesions. Patients were assessed pre and postoperatively using the Visual Analogue Score (VAS), the Stanmore/Bentley Functional Rating Score and the Modified Cincinnati Rating System.

The mean VAS improved from 5.8 pre-operatively to 2 post-operatively. The Stanmore/Bentley Functional Rating Score improved from 2.9 to 0.9 whilst the Modified Cincinnati Rating System improved from 49.8 pre-operatively to 81.3 postoperatively with 87% of patients achieving excellent or good results. All postoperative scores exhibited statistically significant improvement from pre-operative scores.

The results show that, in this particular group of patients, this procedure produces reduction in pain and a statistically significant improvement in function postoperatively. We strongly recommend this procedure in the management of adolescents with symptomatic chondral defects.

Introduction: The London Implant Retrieval Centre (LIRC) was founded to investigate the high incidence of unexplained failures of Metal-on-Metal (MoM) hips. A multidisciplinary team analyse the failed hips, investigations include CT and MRI scans, blood and synovial fluid tests, wear measurements, X-rays and clinical data from the explanting surgeons.

Wear measurements of 100 explanted hips have been carried out on a Taylor Hobson 365 Roundness Machine using the LIRC Wear Protocol. It was found that 50% of explanted cups were wearing less than 5 μm/year and 60% of components were wearing less than 10 μm/year. Wear tests on hip joint simulators predict wear rates between 2 and 8 μm/year. However, 6% of cups are wearing faster than 100 μm/year, with 16% of cups have wear patches deeper than 100 μm and that 4% have a wear patch deeper than 300 μm.

Discussion: This paper considers the common characteristics of components in this very high wearing category. Engineering parameters such as head/cup clearance, surface finish, form errors and head cup contact conditions are investigated. This is correlated with clinical data and other results from the LIRC.

Cup position is an important factor, all of the high wearing components are outside the Lewinick’s Box, however it is shown that mal position is does not always lead to extreme wear. Further analysis is taking place to calculate the size of the contact patch between head and cup (based on patient data and biomechanics) and the proximity of the contact patch to the edge of the cup.

Conclusion: The study of explanted components shows that 6% exhibit extreme wear, and although several “risk” factors can be identified, it is not clear why only a proportion of these components show extremely high wear rates. This is the subject of current investigation.

Introduction: Local problems of metal on metal (MOM) hip arthroplasty such as pseudotumours, neck thinning and osteolysis maybe related to concentrations of cobalt and chromium ions in the synovial fluid. There is little reported on these values. Our aim was to determine the range of metal ion levels in synovial fluid, and to investigate the relationship between these samples and simultaneous blood samples.

Methods: Synovial fluid and whole blood samples were taken from 30 consecutive patients at the time of revision surgery for a painful MOM hip. Aspirated fluid was not visibly contaminated with blood. Impants were in situ for a mean period of 31 months. All had normal renal function. Samples were analysed using ICP mass spectrometry and compared with 10 samples from patients without implants.

Results: The mean (and range) of synovial fluid metal ion levels were 1965 ug/l (30 to 13618) and 6265 ug/l (11 to 81630) for Cobalt and Chromium respectively. There was a good correlation between synovial and blood levels for both cobalt (R=0.65, p = 0.0001) and chromium (R = 0.59, p = 0.006).

Discussion and Conclusion: Metal ions in synovial fluid from MOM hips are generated from wear of the bearing surfaces, the correlation with blood metal ion levels, shown in this study, suggest that blood levels may be used as surrogate marker for hip wear rate. Our range of synovial fluid metal ion levels may be useful for those conducting in vitro studies on the biocompatibility of MOM hips.

Blood metal ions have been widely used to investigate metal-on-metal hip replacements, but their ability to discriminate between well-functioning and failed hips is not known. The Medicines and Healthcare products Regulatory Agency (MHRA) has suggested a cut-off level of 7 parts per billion (ppb).

We performed a pair-matched, case-control study to investigate the sensitivity and specificity of blood metal ion levels for diagnosing failure in 176 patients with a unilateral metal-on-metal hip replacement. We recruited 88 cases with a pre-revision, unexplained failed hip and an equal number of matching controls with a well-functioning hip. We investigated the 7 ppb cut-off level for the maximum of cobalt or chromium and determined optimal mathematical cut-off levels from receiver-operating characteristic curves.

The 7 ppb cut-off level for the maximum of cobalt or chromium had a specificity of 89% and sensitivity 52% for detecting a pre-operative unexplained failed metal on metal hip replacement. The optimal cut-off level for the maximum of cobalt or chromium was 4.97 ppb and had sensitivity 63% and specificity 86%.

Blood metal ions had good discriminant ability to separate failed from well-functioning hip replacements. The MHRA cut-off level of 7 ppb provides a specific test but has poor sensitivity.

High Tibial Osteotomy (HTO) is a recognised method of correction for knee joint malalignment and unicom-partmental osteoarthritis. Long-term results of this technique have been reported and are favourable. Good results have also been reported with Autologous Chondrocyte Implantation (ACI-C, MACI). Malalignment, if present, should be corrected when ACI is performed. Although results have been reported for either procedure separately, the outcomes of combined HTO-ACI remain unreported. The aim of this study was to evaluate functional outcome in patients undergoing combined HTO-ACI procedures.

Twenty three patients undergoing a combined ACI-HTO procedure were identified retrospectively from a larger trial of patients undergoing ACI for symptomatic chondral defects. The mean age of the patients was 36 (28 – 49). The mean follow-up was 54 months (12 – 108) and mean defect size was 689mm2 (range 350 – 1200). Nine patients had ACI-C and HTO, the remainder having MACI and HTO. Pre and post-operative assessment was carried out using the Visual Analogue Score (VAS), the Bentley Functional Rating Score and the Modified Cincinnati Rating System.

The Mean VAS score improved from 7.4 (4 – 10) pre-operatively to 2.9 (0 – 6) post-operatively at the latest follow-up (p< 0.0001). The Bentley Functional Rating Score improved from 2.9 (2 – 4) to 1.8 (0 – 4), which was statistically significant (p< 0.0001). The Modified Cincinnati Rating System improved from 35.2 (20 – 49) pre-operatively to 68.7 (46 – 85) post-operatively (p< 0.0001). Fourteen patients underwent biopsy of the graft site at a mean of 13.7 months: 21% of biopsies were hyaline-like cartilage, 36% were mixed hyaline/fibrocartilage, 29 % were fibrocartilage and 14% were fibrous tissue.

Combining high tibial osteotomy with autologous chondrocyte implantation is an effective method of decreasing pain and increasing function in the short term. Further evaluation of this procedure is required.

Introduction: Autologous Chondrocyte Implantation (ACI) is a treatment option for symptomatic, full-thickness chondral/osteochondral injuries. Goals of surgery and rehabilitation include replacement of damaged cartilage with hyaline/hyaline-like cartilage, leading eventually to improved level of function. Intermediate and long-term results are promising in terms of functional improvement.

Purpose: To explore the hypothesis that non-hyaline cartilage repair tissue is associated with worse functional outcome and to assess whether the quality of the repair tissue formed following ACI improves with time post-surgery.

Methods and Results: Two hundred and forty eight patients who underwent ACI at our institution were studied, having had post-implantation biopsies of the repair tissue. Mean timing of biopsy was 14.8 months (range 3–55). 59 biopsies showed hyaline tissue (24%), 67 mixed hyaline and fibrocartilage (27%), 113 biopsies were fibrocartilage only (46%) and 9 patients had a fibrous tissue biopsy result (9%). 126 patients (51%) had hyaline tissue in the regenerate and demonstrated a mean Modified Cincinnati Rating Score (MCRS) of 84 and a mean Lysholm Score of 88 at last follow-up (Group 1). 122 patients (49%) had no hyaline tissue in the regenerate and scored a mean MCRS of 71 and a mean Lysholm Score of 73 (Group 2). Both Groups 1 and 2 demonstrated a statistically significant improvement in functional outcome between pre and post-operative scores (p< 0.0001). There was significant difference in post-operative scores between Groups 1 and 2 suggesting that presence of hyaline tissue in the regenerate is associated with improved functional outcome (p< 0.05). Finally, our statistical analysis suggested that if time post-implantation doubles, then the likelihood of a favourable histological outcome increases significantly.

Conclusion: ACI forms a durable repair tissue that remodels and continues to improve in quality with time. Poor functional outcome may reflect the presence of a non-hyaline cartilage repair tissue.

Introduction: Autologous chondrocyte implantation (ACI) has been used to treat patella cartilage lesions but several studies have indicated poorer results compared to lesions on the femoral condyles. This paper investigates the effectiveness of two different methods of ACI; porcine-derived collagen membrane as a cover (ACI-C) and matrix-carried autologous chondrocyte implantation (MACI).

Methods: 124 patients (mean age 33.5) with symptomatic osteochondral lesions in the patella were selected to undergo either ACI (56 patients) or MACI (68 patients). 1 year following surgery patients underwent check arthroscopy to assess the graft. Functional assessment was performed pre-operatively, at 6 months and yearly by using the modified Cincinnati score (MCS).

Results: 37.5% of patients experienced good or excellent clinical results according to the MCS in the ACI group compared with 69.2% in the MACI group (p = 0.0011). The mean MCS improved from 43.7 pre-operatively to 49.8 2 years following surgery in the ACI group, whereas in the MACI group the improvement was from 44.6 to 60.6 (p=0.07). Arthroscopic assessment showed a good to excellent International Cartilage Repair Society score in 89.7% of ACI-C grafts and 69.6% of MACI grafts (p = 0.08). There was a higher re-operation rate (p = 0.044) in the ACI group (29%) compared with MACI (10%).

Conclusions: The results from this paper suggest that MACI is more successful in the treatment of patella cartilage lesions than ACI even though arthroscopic assessment showed the converse to be true. The higher complication and re-operation rate suggests that we should be treating such patients with MACI.

High tibial osteotomy (HTO) is a recognised method of correction for knee joint malalignment and unicompartmental osteoarthritis. The long term results of this technique have been reported and are favourable. Autologous chondrocyte implantation (ACI-C, MACI) has also been reported to have good results It is advised that malalignment, if present, should be corrected if ACI is to be performed. Although results have been reported for either procedure separately, the outcomes of combined HTO-ACI remain unreported.

To evaluate functional outcome in a group of patients undergoing combined HTO-ACI procedures.

Twenty three patients undergoing a combined ACI-HTO procedure were identified retrospectively from a larger trial of patients undergoing ACI for symptomatic chondral defects. The mean follow-up was 54 months (range 12 – 108) and the mean defect size was 689 mm2 (range 350 – 1200). Nine patients had ACI-C and HTO, the remainder having MACI and HTO. Pre and postoperative assessment was carried out using the Visual Analogue Score (VAS), the Bentley Functional Rating Score and the Modified Cincinnati Rating System.

The Mean VAS score improved from 7.4 pre-operatively to 2.9 post-operatively (p< 0.0001). The Bentley Functional Rating Score improved from 2.9 to 1.8 (p< 0.0001) whilst the Modified Cincinnati Rating System improved from 35.2 pre-operatively to 68.7 post-operatively (p< 0.0001). There was no significant difference between ACI-C and MACI. Two patients developed a non union at a mean of 13 months and a further two patients had a failure of the chondrocyte graft at a mean of 22.5 months.

Combining high tibial osteotomy with autologous chondrocyte implantation is an effective method of decreasing pain and increasing function at mean of 54 months follow-up. Further follow-up is required to assess the long term outcomes of these combined procedures.

Non-invasive expandable prostheses for limb salvage tumour surgery were first used in 2002. These implants allow ongoing lengthening of the operated limb to maintain limb-length equality and function while avoiding unnecessary repeat surgeries and the phenomenon of anniversary operations.

A large series of skeletally immature patients have been treated with these implants at the two leading orthopaedic oncology centres in England (Royal National Orthopaedic Hospital, Stanmore, and Royal Orthopaedic Hospital, Birmingham).

An up to date review of these patients has been made, documenting the relevant diagnoses, sites of tumour and types of implant used. 74 patients were assessed, with an age range of 7 – 16 years and follow up range of 4 – 88 months.

We identified five problems with lengthening. One was due to soft tissue restriction which resolved following excision of the hindering tissue. Another was due to autoclaving of the prosthesis prior to insertion and this patient, along with two others, all had successful further surgery to replace the gearbox. Another six patients required mechanism revision when the prosthesis had reached its maximal length. Complications included one fracture of the prosthesis that was revised successfully and six cases of metalwork infection (two of which were present prior to insertion of the implant and three of which were treated successfully with silver-coated implants). There were no cases of aseptic loosening.

Overall satisfaction was high with the patients avoiding operative lengthening and tolerating the non-invasive lengthenings well. Combined with satisfactory survivorship and functional outcome, we commend its use in the immature population of long bone tumour cases.

We measured the orientation of the acetabular and femoral components in 45 patients (33 men, 12 women) with a mean age of 53.4 years (30 to 74) who had undergone revision of metal-on-metal hip resurfacings. Three-dimensional CT was used to measure the inclination and version of the acetabular component, femoral version and the horizontal femoral offset, and the linear wear of the removed acetabular components was measured using a roundness machine.

We found that acetabular version and combined version of the acetabular and femoral components were weakly positively correlated with the rate of wear. The acetabular inclination angle was strongly positively correlated with the rate of wear. Femoral version was weakly negatively correlated with the rate of wear. Application of a threshold of > 5 μm/year for the rate of wear in order to separate the revisions into low or high wearing groups showed that more high wearing components were implanted outside Lewinnek’s safe zone, but that this was mainly due to the inclination of the acetabular component, which was the only parameter that significantly differed between the groups.

We were unable to show that excess version of the acetabular component alone or combined with femoral version was associated with an increase in the rate of wear based on our assessment of version using CT.

This study compared component wear rates and pre-revision blood metal ions levels in two groups of failed metal-on-metal hip arthroplasties: hip resurfacing and modular total hip replacement (THR).

There was no significant difference in the median rate of linear wear between the groups for both acetabular (p = 0.4633) and femoral (p = 0.0872) components. There was also no significant difference in the median linear wear rates when failed hip resurfacing and modular THR hips of the same type (ASR and Birmingham hip resurfacing (BHR)) were compared.

Unlike other studies of well-functioning hips, there was no significant difference in pre-revision blood metal ion levels between hip resurfacing and modular THR.

Edge loading was common in both groups, but more common in the resurfacing group (67%) than in the modular group (57%). However, this was not significant (p = 0.3479). We attribute this difference to retention of the neck in resurfacing of the hip, leading to impingement-type edge loading. This was supported by visual evidence of impingement on the femur.

These findings show that failed metal-on-metal hip resurfacing and modular THRs have similar component wear rates and are both associated with raised pre-revision blood levels of metal ions.

Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%).

Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18).

Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation.

Non-bacterial osteitis (NBO), a term referring to sterile bone lesions with non-specific histopathological features of inflammation, may be either uni- or multifocal, acute (6 months) or chronic, and recurrent. Only when the condition is chronic, recurrent and multifocal is it appropriate to use the term chronic recurrent multifocal osteomyelitis (CRMO).

We present our clinical experience as the largest reported series of children with NBO to date. Of 41 children (2–16 years) diagnosed with NBO in our institution over the last 6 years, 21 (51%) had recurrent disease and 18 of 41 (44%) had multifocal disease. The most common bones affected were the clavicle, femur and tibia (in order of decreasing prevalence) accounting for 44 (63%) of a total of 70 lesions. Only one individual had SAPHO syndrome and no other patients had evidence of bowel or skin disease. In the absence of evidence for an infective aetiology, we recommend non-steroidal anti-inflammatory agents as first line therapy, and bisphosphonates only in cases of resistant disease.

On the basis of our findings we propose a patient questionnaire and protocol for investigating and managing patients who present to orthopaedic surgeons with NBO. We predict that this will benefit patients with this disorder by providing valuable information about the pathogenesis, clinical outcome and response to treatment. In the future, clarification of the pathogenesis of this disease will undoubtedly help rationalise the therapeutic approach improving both quality of life and outcome for these patients.

Introduction: The aim of the study was to review the long-term survival and outcome of 49 consecutive endoprosthetic lower limb diaphyseal replacements undertaken for neoplastic conditions.

Methods: A retrospective review of all femoral and tibial diaphyseal replacements performed between 1990 and 2009 at our specialist bone and soft tissue tumour unit was performed. Minimum follow-up was one year. Joint sparing prostheses were excluded.

Results: 49 femoral (31) and tibial (18) diaphyseal replacements were implanted into 46 patients (31 male, 15 female). Mean age at surgery was 47 years (range 9–79). Surgery was performed for malignancy in 46 cases (97%), of which 41 (89%) were primary bone and soft tissue sarcomas. The predominant pathologies were osteosarcoma (24%), malignant fibrous histiocytoma (14%) and chondrosarcoma (14%). Mean follow-up was 81 months (range 12–221 months). Survival within the follow-up group was 96% at 1 year, 79% at 5 years, and 69% at 10 years. In surviving patients, using revision, recurrence and amputation as endpoints, prosthesis survival was 91% at 1 year, 58% at 5 years, and 33% at 10 years. In total, 13 prostheses underwent revision surgery and there were 3 amputations following diaphyseal replacement. Of these 16 cases, 75% were for aseptic loosening or prosthetic failure, 13% for tumour recurrence, and 13% for infection.

Discussion: Lower limb diaphyseal endoprosthetic replacements are a useful surgical treatment method for patients with malignant neoplastic diaphyseal bone lesions requiring excision and reconstruction. This is both limb salvage and joint-sparing reconstructive surgery.

Introduction: The Musculoskeletal Tumour Society recommends that patients with musculoskeletal tumours are treated in specialist centres. Core needle biopsy is an effective method of obtaining tissue diagnosis but a dilemma arises when the material is non-diagnostic. Our aim was to evaluate the management of non-diagnostic biopsies.

Method: We retrospectively reviewed all core needle biopsies performed between 2003 and 2009 in our regional centre. Non-diagnostic biopsies were identified and management reviewed.

Results: 4,520 core needle-biopsies were performed of which 120 (2.6%) were non-diagnostic. Of these 85 (70%) were treated definitively on the basis of existing imaging, 8 (7%) required further imaging before treatment and 27 (23%) had a repeat biopsy.

Of the 27 repeat biopsies a positive histological diagnosis was obtained in 22 patients. The remaining 5 were again non-diagnostic giving a total of 98 patients being treated definitively without a tissue diagnosis.

Of these 98 cases, 39 (40%) were treated non-operatively, 37 (38%) had curettage and 22 (22%) underwent wide excision.

In the curettage group 33 out of 37 patients had a benign tumour on final histology. Four patients turned out to have intermediate/high grade tumours and subsequently underwent wide excision.

In the wide excision group, 17 out of 22 patients had an intermediate/high grade tumour on final histology. Five patients underwent an unnecessarily wide excision of a benign lesion.

None of the patients treated non-operatively turned out to have a tumour.

Conclusion: After non-diagnostic core-needle biopsy, the patient can safely be managed without tissue diagnosis, with low error rate, provided they have been subjected to a multidisciplinary discussion.

Objectives:

To determine the diagnostic performance of image-guided percutaneous core needle biopsy (CNB) in patients presenting with pathologic fractures of the appendicular skeleton.

A retrospective audit identified 129 consecutive patients presenting with pathological fractures to a specialist orthopaedic oncology unit over a 9 year period. All patients underwent percutaneous CNB using CT (n=98), fluoroscopy (n=15) or US (n=16) guidance. In all cases MRI or CT was available prior to biopsy to assess the presence and degree of extra-osseous tumour mass. The resulting sample was classified as diagnostic (Group 1) or non-diagnostic (Group 2) on histopathological study. Diagnostic performance was evaluated on the basis of the diagnostic yield and accuracy; these were related to the site of the lesion and presence/absence of extra-osseous mass.

Of 129 biopsies, 99 (77%) were classified as Group 1 and 30 (23%) as Group 2. The commonest sites of pathological fracture without associated soft tissue component and resulting in a non-diagnostic biopsy were the proximal femur and proximal humerus. The average cross-sectional diameter of lesions in Group 1 was 5.7 x 5.9cm. Of the 30 lesions comprising Group 2, no soft tissue component was identified on pre-biopsy cross-sectional imaging in 27 lesions (90%) whereas the remaining 3 (10%) showed a smaller extra-osseous soft tissue component compared to the lesions in Group 1.

Image-guided percutaneous CNB is a reliable method for obtaining a tissue diagnosis in patients presenting with a pathologic fracture of the appendicular skeleton with high accuracy rate. However, those lesions which are purely intra-osseous or have only very small extra-osseous components are likely to be associated with a non-diagnostic biopsy, and should be considered for a primary open procedure.

Disarticulation of the hip in patients with high-grade tumours in the upper thigh results in significant morbidity. In patients with no disease of the proximal soft tissue a femoral stump may be preserved, leaving a fulcrum for movement and weight-bearing. We reviewed nine patients in whom the oncological decision would normally be to disarticulate, but who were treated by implantation of an endoprosthesis in order to create a functioning femoral stump. The surgery was undertaken for chondrosarcoma in four patients, pleomorphic sarcoma in three, osteosarcoma in one and fibrous dysplasia in one. At follow-up at a mean of 80 months (34 to 132), seven patients were alive and free from disease, one had died from lung metastases and another from a myocardial infarction. The mean functional outcome assessment was 50 (musculoskeletal tumor society), 50 and 60 (physical and mental Short-form 36 scores).

Implantation of an endoprosthesis into the stump in carefully selected patients allows fitting of an above-knee prosthesis and improves wellbeing and the functional outcome.

Elastofibroma dorsi is a rare, benign, slow-growing ‘pseudotumour’ classically presenting as an ill defined mass at the inferior pole of the scapula. Typical symptoms include mass, pain, scapular snapping and impingement like features. There is a predilection for females after the fifth decade of life. The aetiology is unclear.

We identified 15 patients (21 tumours) with a diagnosis of elastofibroma. Seven lesions were found on the left side and fourteen on the right; bilateral lesions were found in six patients. The male:female ratio was eight:seven and mean age at presentation was 60.9 years (range 40 – 71). The mean duration of symptoms (most commonly pain, mass and scapular snapping) prior to presentation was 25.8 months. Eighteen tumours were excised with a mean follow-up of 4.2 years (0.25–16). Four lesions were diagnosed by combined MRI and CT guided biopsy, the remainder identified using MRI alone. All patients were asked specifically about symptoms, occupation, family history and employment history (including hobbies). Pain was assessed using the Visual Analogue Score (VAS) and functional outcome using the Stanmore Percentage of Normal Shoulder Assessment (SPONSA) Score. Range of forward flexion of the shoulder joint was also assessed.

In the operative group, the mean VAS score improved from 4.6 (0–10) pre-operatively to 2.5 (0–8) post-operatively. Mean SPONSA scores improved from 61.5% (20 – 100) to 81.8% (30 – 100). Mean pre-operative forward flexion was 135 degrees (70 – 180), this improved to 166 degrees (100 – 180) post-operatively. A high number of patients had been involved in occupations involving heavy lifting. MRI had a 100% sensitivity in identifying elastofibroma when correlated with histopathological evaluation.

This series demonstrates that elastofibroma may be reliably diagnosed using MRI alone and, in the symptomatic patient, pain and function may be improved through operative excision.

Background: There is no consensus on the most appropriate prosthesis for treating osteoarthritis (OA) of the hip in young, highly active patients. Modern hip resurfacing is bone conserving, more stable and theoretically easier to revise than total hip arthroplasty. Early results of metal on metal resurfacing have been promising. We have compared two well matched cohorts of patients with regard to function, pain relief and patient satisfaction.

Methods: This prospective study included 2 cohorts of well matched patients treated with hip resurfacing (137 patients, 141 hips) and custom uncemented (CADCAM) stems (134 patients, 141 hips). All procedures were performed by a single surgeon. Outcome measures included Oxford, WOMAC and Harris hip scores. Statistical analysis was performed using the unpaired student’s t- test.

Results: One hundred and thirty four and 137 patients were included in the hip replacement and resurfacing groups respectively. The mean age of these patients was 54.6 years. The mean duration of follow up for the resurfacing group was 19.2 months compared to 13.4 months for the replacement group.

Pre operative oxford, Harris and WOMAC scores in the THA group were 41.1, 46.4 and 50.9 respectively while the post operative scores were 14.8, 95.8 and 5.0. In the HR group, pre- operative scores were 37.0, 54.1 and 45.9 respectively compared to 15.0, 96.8 and 6.1 post operatively. The degree of improvement was similar in both groups.

Conclusion: There was no significant difference in short term outcome between the groups of patients treated with hip resurfacing and total hip arthroplasty in the short term.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue neoplasm most commonly presenting in young to middle-aged adults. LGFMS is an indolent tumour with a deceptively benign histological appearance. Local recurrences are not uncommon and the tumours can metastasise. A particular gene translocation, FUS-CREB3L2, has been shown to occur commonly in cases of LGFMS. The literature suggests that the FUS-CREB3L2 fusion-gene is a specific marker for LGFMS.

We report the cytogenetic analysis of 29 cases of LGFMS, and clinical outcomes of 21 patients treated surgically between 1998 and 2008 at our regional bone and soft-tissue tumour centre. The mean age was 45.4 years. The most common location of tumours in our series was the lower limb. The mean follow-up was 30.1 months (range 0 to 125 months). To date, there have been no cases of local recurrence or metastasis.

Fifteen of our patients (52.2%) were FUS-CREB3L2 translocation-positive. This suggests either that the translocation incidence in our LGFMS series is lower than other studies, or that reverse-transcriptase polymerase chain reaction (PCR) is substantially less sensitive than the literature suggests. The patients in this series testing positive presented at a younger age (38.2 years, compared to 45.6 years), and had larger tumours than their negative counterparts (mean diameter 97.6mm, compared to 65.2mm), although there was no difference in clinical outcome.

We conclude that PCR testing for the FUS-CREB3L2 translocation is a useful tool for confirming the diagnosis of LGFMS, but has no role in predicting short-term clinical outcome. In our experience it is not necessary to perform wide excision, and marginal margins are adequate. Longer-term follow-up is required to elucidate whether the previously reported recurrence and metastasis rates are a true reflection of the nature of this tumour, and may identify differences in the long-term clinical outcome between translocation-positive and negative patients.

Within a study group of 102 consecutive patients diagnosed at a supra-regional bone tumour unit with chondrosarcoma of the femur, tibia or humerus, an association with previously treated breast cancer was noted.

There were 58 female patients and 44 male patients. The study group contained six females (10%, mean age 53 years) who had previously been treated for breast cancer, a higher proportion than would be expected. They were referred following identification of a solitary area of increased activity on routine screening with isotope bone scan, presumed to be a solitary bony metastasis.

Most (86%) of this breast carcinoma sub-group had developed low-grade bone chondrosarcoma (Trojani grade 0.5-I) and only one case (14%) had developed high-grade chondrosarcoma (Trojani grade II-III).

A suspicious long bone lesion on bone scan in a patient with a past medical history of breast cancer must, therefore, not be assumed to be a metastasis without further investigation; the possibility of a chondral lesion should be considered. It is important that patients receive a full multidisciplinary team investigation prior to treatment in order to obtain the correct tissue diagnosis, as the management of these conditions is often different.

Our study suggests there may be a relationshipbetween patients previously treated for breast cancer and the development of subsequent chondrosarcoma.

Introduction: One of the most important factors affecting the outcome of revision THR of the femoral stem is the variability of femoral endosteal geometry after removal of the in-situ stem. A custom made implant would greatly reduce the inventory of the ‘Off the shelf” (OTS) components. This study presents the medium to long-term results of a cohort of patients with this revision prosthesis.

Methods: During the period November 1991 to November 1998, 158 patients were implanted with a computer-assisted design and computer-assisted manufactured (CAD-CAM) revision prostheses (Stanmore Implants Worldwide, Biomedical Engineering Unit, RNOH) by the senior author (SMA). There were 97 males and 61 females. The average age was 63.1 years (34.6 – 85.9). The indications for revision surgery were aseptic loosening (135 cases, 85.4 %), peri-prosthetic fractures (6 cases, 3.8 %), infection (12 cases, 7.6%) and liner wear (3 cases, 1.9%).

Results: At 10 years all patients reported relief of pre-operative pain and the average hip flexion was 95o (90 o –110o). Oxford, Harris and WOMAC hip scores in the pre-operative and post-operative period were 41.1, 44.2 and 52.4 respectively and 18.2, 89.3 and 12.3 respectively (p< 0.0001, p< 0.0001, p< 0.0001).

There were 6 complications (3.8%) in this series; a periprosthetic fracture of the femoral diaphysis (1), posterior dislocation (2), failure secondary to aseptic loosening of the implant (1) and deep vein thromboses (2)

Discussion: These ten year results are encouraging and suggest that there is a role for the use of custom implants in revision THR, particularly where the anatomical variance of the proximal femur makes the use of OTS implants unsuitable.

Granular Cell Tumours are rare mesenchymal soft tissue tumours that arise throughout the body and are believed to be of neural origin. They often present as an asymptomatic slow-growing benign solitary lesion but may be multifocal. One to two percent of cases are malignant and can metastasise.

Described series in the literature are sparse. We examined our database and identified eleven cases in ten patients treated surgically and followed-up for a period of over six years (May 2002 to January 2009) in our regional bone and soft tissue tumour centre.

Five tumours were located in the lower limb, four in the upper limb and two in the axial skeleton. Mean patient age was 31.2 years (range 8 to 55 years). Excision was complete in one case, marginal in five cases and intra-lesional in five cases. No specimens showed evidence of malignancy. No patients required postoperative adjuvant treatment. Mean follow-up was 19.3 months (range 1 to 37 months), with no cases of local recurrence. One case was multi-focal.

Histopathological examination revealed the classical features of granular cell tumour in all cases. Typically, tumour cells were diffusely and strongly positive for S100 protein by immunohistochemistry, whereas the other markers tested were negative.

We believe this case series to be the largest of its type in patients presenting to an orthopaedic soft tissue tumour unit. We present our findings and correlate it with findings of other series in the literature.

Purpose: To determine if Cobalt-Chrome (CoCr) femoral components of knee replacement components roughen significantly, and when significant roughening may start.

Methods:

Retrieval study:

14 knee replacement components were retrieved after revision procedures. The average surface roughness (Ra) of the articulating regions of each condyle was measured by surface profilometry and compared to Ra of non-articulating regions, which acted as controls on each implant.

In vitro testing:

Pin-on-plate testing of 6 paired CoCr pins and vacuum γ-irradiated UHMWPE discs was carried out under a force of 2.3kN at 1Hz to investigate how the articular Ra of CoCr pins varied with increasing number of cycles. Ra was measured at 0, 10, 100 and 1000 cycles using surface profilometry.

Results:

Retrieval analysis:

Average medial femoral condyle Ra was significantly greater than control Ra (p=0.040). Average lateral femoral condyle Ra was not significantly greater than control Ra (p=0.158). Significantly higher average Ra was seen on the medial condyles when compared with the lateral condyles (p < 0.05). 8/14 retrieved femoral components had ≥1 significantly roughened condyle (p< 0.05).

In vitro testing:

At 100 and 1000 cycles the Ra of the CoCr pins was significantly greater than Ra at 0 cycles (p< 0.05).

Conclusion: A large proportion of femoral components of knee replacement implants roughen significantly in vivo, a finding supported by our in vitro testing which indicates that roughening may begin very early on. This may have important implications for aseptic loosening of knee replacement components. However, the average Ra of those CoCr surfaces significantly (p< 0.05) roughened was within acceptable limits for orthopaedic implants (0.050μm).

Chondrosarcoma is the second most common primary malignant bone tumour. Distinguishing between grades is not necessarily straightforward and may alter the management of the disease. We evaluated the correlation between the pre-operative needle biopsy and excision biopsy histological grading of chondrosarcoma of the femur, tibia and humerus.

A consecutive retrospective series of 100 patients with a histological diagnosis of chondrosarcoma was reviewed. Twenty-one patients were excluded because 20 had only excision biopsy and one had only the pre-operative biopsy on record, thus this series included 79 available cases. In 11 instances, there was a discrepancy in histological grade.

Therefore, there was an 86% (68 out of 79) accuracy rate for pre-operative histological grading of chondrosarcoma, based on needle biopsy. However, the accuracy of the diagnostic biopsy to distinguish low-grade from high-grade was 90% (71 out of 79).

Introduction: While the explant device has made revision of uncemented acetabular components technically easier, the unique design of the Birmingham Hip Resurfacing(BHR) acetabular component precludes the use of the standard explant extractor. The dual radius geometry of this socket causes impingement and damage to the curved blade of this device.

A novel adaptor was designed to correct for the differential radii and enable removal of the well fixed BHR socket with the explant. We present the results of our initial experience with this device.

Method: A prospective study was performed to evaluate the effectiveness of this device for revising the well fixed BHR socket. All cases were performed by a single surgeon via a posterior approach.

The explant cup extractor was used with its standard centering head and curved blades. The size of the explanted cup, last reamer size and size of the implanted component were recorded

Results: Three males and 7 females were included. Their average age was 58.1 years (48–65). Average time to revision of the BHR sockets was 24.2 months (7–40). Average explanted cup size was 51mm (46–58) and final reamer size 53.8mm (51–59). Average final socket size was54.8 (50–62). Overall there was a mean 2.8.mm size difference between the explanted cup and the final reamer.

Discussion: The thickness of the blade of the explant was 2mm therefore only 0.8 mm of bone was lost on average. The device enables a simple reproducible removal of the well fixed BHR sockets with preservation of acetabular bone stock.

Introduction: Autologous Chondrocyte Implantation (ACI) is a treatment option for full-thickness chondral, or osteochondral injuries that are painful and debilitating. Goals of surgery and rehabilitation include replacement of damaged cartilage with hyaline or hyaline-like cartilage, leading eventually to improved level of function. Intermediate and long-term results are promising in terms of functional and clinical improvement.

Purpose: To explore the hypothesis that the quality of the repair tissue, formed following Autologous Chondrocyte Implantation (ACI), improves with time post-surgery.

Methods and Results: Two hundred and forty eight patients who underwent autologous chondrocyte implantation in our institution were studied after having had post implantation biopsies of the repair tissue. Mean timing of biopsy was 14.8 months (range 3–55). 59 biopsies gave hyaline tissue (24%), 67 mixed hyaline and fibrocartilage (27%), 113 biopsies were fibrocartilage only (46%) and 9 patients had a fibrous tissue biopsy result (9%). Due to NHS restraints and waiting list targets biopsies were actually performed at various time points post implantation allowing us to statistically correlate histological findings with the maturity of the repair tissue.

Our statistical analysis suggests that if time post implantation doubles then the likelihood of a favourable histological outcome increases significantly.

Conclusion: Autologous chondrocyte implantation forms a durable repair tissue that remodels and continues to improve in quality with time. It is recommended that for future research/study purposes 24 months is used as an optimal time to look at histology, since our data show that outcome is still improving until this point.

Medical records of children < /=5 years, treated by the London sarcoma service for malignant primary bone tumours (average new cases osteosarcoma (OS)/Ewings sarcoma (ES), all ages: 125/year) between 1999 and 2009, were reviewed.

Results: 5 OS and 6 ES. Mean age – 4.2 years (range 2.1–5.8), 8/11 males. OS primary sites: distal femur (2), proximal femur (1) and proximal humerus (2); localised tumours only. Primary sites in the ES cohort included 1 distal femur, 2 chest wall (1 – spinal extension), 1 buttock (spinal extension), 1 temporal bone and 1 ulna; 1 had bone/bone marrow involvement, 1 had chest metastases. 4/5 OS (Euramos, MRC B007) and 5/6 ES (Euro-Ewings 99) were entered into phase III clinical trials. Delayed surgery for OS occurred at mean 12.1 weeks (range 11–13) – 4 limb salvage prostheses with 2/4 non-invasive growers, 1 forequarter amputation. All had a good (> 90% necrosis) histologic response to neoadjuvant therapy. Delayed surgery for ES occurred at mean 21.7 weeks (range 12.8 – 35), 1 limb salvage with prosthesis (non-invasive grower), 1 biological reconstruction; remainder had tumour resections. Histologic response: 50% good. In the OS cohort, 1 child died a toxic death; 1 developed pulmonary metastases and died 2 years from diagnosis; 1 has a metastatic recurrence in the opposite humerus 2 years from diagnosis and starts 2nd line therapy; 1 had local recurrence 1 year from diagnosis but alive at 7.4 years;1 alive/disease free at 2.5 years. In the ES cohort 5/6 are alive disease free -1, 4.1, 5.2, 6.9 and 7 years from diagnosis; 2 needed 2nd line therapy for recurrent distant disease 4.5 and 5.8 years off therapy, 1 of whom has just recurred again (6.1 years from diagnosis).

Conclusion- improving early survival rates in the very young with OS remains a significant challenge. Quality of survival requires further age-appropriate study.

Introduction: Initial results for the management of osteochondral defects with both ACI-C and MACI have been encouraging, showing significant clinical improvement. This single-centre study set out to determine any significant difference in outcomes between ACI-C and MACI.

Aim: Reporting three year follow up of clinical and arthroscopic assessment of prospective analysis of ACI-C and MACI used in the management of symptomatic, full-thickness chondral and osteochondral defects in the knee.

Method: Following assessment arthroscopy and harvesting of chondrocytes for culture, patients were randomised into the ACI-C or MACI arm and underwent their respective procedures one month later. In ACI-C a covered technique is employed using a porcine-derived type I/III collagen membrane sutured in place; MACI requires cultured autologous chondrocytes to be seeded in a bi-layered type I/III collagen membrane which is glued into position. An arthroscopy was performed at 12 and 24 months postprocedure to assess graft coverage and biopsies taken to determine extent of hyaline, mixed and fibro-cartilage proliferation.

Results: 102 patients underwent either ACI-C (44) or MACI (58) with an average age of 33.6 (14–52). Mean Cincinnati knee rating scores recorded prior to assessment arthroscopy for ACI-C: 45.2 (10 – 94) and MACI: 45.5 (10 – 90) showed improvement at follow up with 63% of patients in the ACI-C group scoring good or excellent at three years, and 60% in the MACI group. ICRS arthroscopy scores were good or excellent in 91.4% of ACI-C and 76.1% of MACI patients at 24 months. Biopsies of the transplants at 24 months revealed proliferation of hyaline and mixed cartilage (hyaline and fibro-cartilage) in 48.6% of the ACI-C and 30.5% of the MACI patients.

Conclusion: Results to date suggest significant clinical and arthroscopic improvement following ACI-C and MACI, with evidence of proliferation of hyaline cartilage at the transplant site. Limited differences are noted between the outcomes of the two techniques.

Purpose: We attempted to identify whether patients with early evidence of osteoarthritis (OA) on their pre-operative radiographs were associated with poorer outcomes after Autologous Chondrocyte Implantation (ACI).

Methods: We retrospectively reviewed radiographs of 94 consecutive patients who underwent ACI and had already had their knee function assessed according to the Modified Cincinatti Score 2 years following surgery. Changes were graded according to The Kellgren and Lawrence (K& L) and the Stanmore grading system. Two independent observers analysed the films to assess the reproducibility and accuracy of these grading systems for assessment of OA in the knee.

Results: Patients were divided into 2 groups; Group A were patients with excellent/good outcome (52 patients), those with fair/poor outcome were Group B (42 patients).13 patients in Group A and 21 patients in Group B had radiographic evidence of OA (p< 0.025). In 34 patients who had OA (mean age 33.6) the increase in Cincinatti score following surgery was minimal (33.5 to 37.5). In 60 patients where there was no evidence of OA (mean age 33.7) the score increased from 40 to 53.4. The inter-observer variation was greater using K& L (Kappa=0.31) compared with the Stanmore grading systems (Kappa=0.72).

Conclusions: Patients with early radiographic evidence of OA are unlikely to gain maximum benefit from ACI. Furthermore, we recommend the use of Stanmore grading system for the assessment of OA as it is more reproducible than the K& L grading system.

Introduction: The use of custom made CAD-CAM femoral stems in primary Total Hip Replacement allows preservation of valuable bone stock in anatomically challenging femora whilst optimising biomechanics and improving function. The custom prosthesis design and manufacturing process is carried out with the aid of computed tomography (CT), a system of tomographic image processing, a Computer–Aided Design (CAD) system and a Computer–Aided Manufacturing (CAM) system.

Aim: To report seven year minimum follow up of a custom made and designed femoral component used in total hip replacement, focusing on clinical and radiographic evidence of failure.

Methods: Patients who had an uncemented total hip arthroplasty, by one of the two senior authors, with a CAD-CAM hip between February 1993 and February 2000 were retrospectively studied. An independent observer evaluated all patients radiologically using Engh’s criteria of osteointegration and clinically using Harris and Oxford Hip Scores.

Results: 85 patients (47 male, 38 female) (102hips) underwent THA for a variety of reasons between February 1993 and February 2000. Average age was 53.7 (25.4–91.5). Average follow up was 9.3 years (7–15). The aetiologies for THA were: Developmental Dysplasia of Hip (22 hips), Osteoarthritis (25), Slipped Upper Femoral Epiphysis (3), Skeletal Dysplasia (11), Trauma (9), Perthe’s Disease (6), Avascular Necrosis (14), Tumour (4) and other (8). At last follow up 4 hips had been revised: 2 for aseptic loosening, 1 for deep infection and 1 for excessive acetabular cup liner wear. 84 patients were evaluated (one deceased from unrelated causes). Average Harris Hip Score was 81 (range 53–96). Average Oxford Hip Score was 24 (range15–43). A full set of x-rays was available for 73 patients and when evaluated all were radiographically stable. Endosteal bone formation or spots welds were present on all 73 of the x-rays. Radiolucent lines at the bone-implant interface were present on 7/73 x-rays but did not correlate with clinical problems. There was no evidence of bone pedestal formation.

Conclusions: Clinical results are good to excellent with little radiographic evidence of failure. CAD-CAM hips can be safely and reliably used for a variety of aetiologies with predictable result at least up to seven years postoperatively.

Introduction: The non-invasive growing prosthesis continues to be used successfully for the treatment of limb salvage operations in tumour patients. We report our continued experience in 17 skeletally immature patients with osteosarcoma of the distal femur.

Methods: Patients had a mean age of 10.2 years (range 6 to 15) at the time of surgery. The endoprosthesis was lengthened at appropriate intervals in outpatient clinics without anaesthesia using the principle of electromagnetic induction.

Results: The mean follow-up was 28 months (range 2 to 55). The prostheses were lengthened by a mean of 47.4 mm (range 0.5 to 208) and maintained a mean knee flexion of 110 degrees (range 90 to 120 degrees).

Complications developed in seven patients: two implants failed requiring revision, one peri-prosthetic fracture occurred, one developed a flexion deformity of 25 degrees at the knee joint, which was subsequently overcome and three died of disseminated disease.

Discussion: The medium term results from patients treated with this device have continued to show a promising outcome. Four patients successfully completed desired lengthening, six patients are continuing with ongoing lengthening. The implant avoids multiple surgical procedures, general anaesthesia and assists in maintaining leg-length equality.

Orthopaedic surgeons vary in their attitude towards resurfacing of the patella in total knee arthroplasty. Few studies are available to assess outcome and patient preference. We evaluated post-operative anterior knee pain and knee preference in patients with bilateral knee replacements and unilateral patellar resurfacing.

We reviewed 30 patients who had undergone bilateral knee replacement with patellar resurfacing on only one side. Follow-up was from five to 12 years and the patients were assessed using the Knee Society rating, an anterior knee pain rating and a satisfaction score. Patients were also asked specifically if they had a preference for either knee. Assessment was performed without knowing which patella had been resurfaced.

Fourteen patients (47%) favoured the resurfaced knee, six (20%) the un-resurfaced knee and 10 (33%) had no particular preference. The overall prevalence of anterior knee pain was 50% in the un-resurfaced cases (six mild, six moderate, three severe) and 20% in the resurfaced knees (four mild, two moderate). No significant difference was found between knee scores. Three un-resurfaced patellae have been secondarily resurfaced.

This study shows a significant preference for the resurfaced side (p< 0.01), with a higher prevalence of anterior knee pain in non-resurfaced patellae (p< 0.05).

Introduction: Pathological fractures commonly undergo biopsy to establish tissue diagnosis and plan definitive surgical management.

Methods: 129 patients undergoing image-guided needle biopsy of a pathological fracture between 1998 and 2007 were prospectively identified. Imaging was by CT, ultrasound or fluoroscopy. Biopsy was by Jamshedi, Temno or Trucut needle. The outcome measure was ability to make a tissue diagnosis by this method.

Results: The median age at diagnosis was 43 years. 59% were male, 41% female. The four most common sites of pathological fracture were the femur (35%), humerus (28%), tibia (12%) and pelvis (11%).

The five most common histopathological diagnoses were chondrosarcoma (9%), osteosarcoma (9%), meta-static renal carcinoma (8%), giant-cell tumour (6%), lymphoma (5%).

77% of biopsies yielded a tissue diagnosis. The remaining 23% underwent open biopsy, repeat image-guided needle biopsy or were not further investigated.

In the 30 cases (23%) of non-diagnostic biopsies 80% of these lesions had no extra-osseous component to them and the remaining 20% had a very small extra-osseous component.

Discussion: A tissue diagnosis of a pathological fracture can be obtained by primary image-guided needle biopsy in 77% of cases referred to a specialist bone tumour service. The majority (80%) of unsuccessful biopsies were of lesions with little or no extra-osseous component to the lesion.

Our aim was to review the short-term clinical results of a single-institution cohort undergoing opening wedge high tibial osteotomy (HTO).

We undertook a prospective clinical and radiographic review of our cohort of patients who had undergone opening wedge HTO for varus malalignment. The Cincinnati scoring system was used for objective assessment. Pre- and post-operative radiographs were evaluated and Blackburne-Peel (BP) and Insall-Salvati (IS) ratios recorded, as well as integrity of the lateral hinge.

We reviewed 55 knees (51 patients: 34 men and 17 women; mean age, 44.2years; range 34–58years) followed up for a minimum 12 months (range, 12–62months). All patients had relief of pain, but six met our criteria of failed treatment where either revision fixation was required or proceeded to total knee arthroplasty for persisting symptoms. Cincinnati scores were 94.5% excellent (52/55) and 5.5% good (3/55) at 1 year, whilst at last follow-up they were 87.2% excellent (48/55), 9.1% good (5/55) and 3.6% fair (2/55). There was a significant improvement in mean American Knee Society score at 1 year and maintained at last follow-up (p< 0.05). Radiographically the lateral hinge was noted to be breached in 9.1% (5/55), but no incidence of non-union was identified. There was no significant change in IS index, however BP index diminished by a mean 15.3% (range, 7.4–28.2%). Medial opening wedge tibial osteotomy results in patellar infera, but successful clinical and functional outcomes have been demonstrated. The fact ther e is inconsistency between the two indices assessing patellar height ratio we believe reflects the inherent variability in the techniques employed. Distalisation of the tibial tubercle will mean the IS ratio remains unaffected, whilst the BP index more accurately demonstrates the lowering of patella relative to the joint line. However there may be other factors which are not immediately appreciated, such as changes in the tibial inclination or antero-posterior translation.

We retrospectively studied 67 patients who underwent proximal humeral replacement with the Bayley-Walker prosthesis, for tumour of the proximal humerus between 1997 and 2007. Of the 67 patients 10 were lost to follow up. Of the 41 surviving patients, function was assessed using the Musculoskeletal Tumour Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) questionnaire.

4 of the 41 patients received the new Bayley-Walker ‘captured’ proximal humeral replacement. The mean age was 46 years (7–87). The mean MSTS score at follow-up was 72.0 % and the mean TESS score was 77.2 %. The sub-group of 4 pts who received the new captured prosthesis had a mean MSTS score of 77.7 %. There was no mechanical failure of any prostheses in the follow up period.

Endoprosthetic replacement for tumour of the proximal humerus with the Bayley-Walker prosthesis, is a reliable operation yielding reasonable functional results and good long-term prosthesis survivorship. The performance of this prosthesis is expected to improve further with the new ‘captured’ prosthesis.

Our aim was to review the short-term clinical results of a single-institution cohort undergoing opening wedge high tibial osteotomy (HTO).

We undertook a prospective clinical and radiographic review of our cohort of patients who had undergone opening wedge HTO for varus malalignment. The Cincinnati scoring system was used for objective assessment. Pre- and post-operative radiographs were evaluated and Blackburne-Peel (BP) and Insall-Salvati (IS) ratios recorded, as well as integrity of the lateral hinge.

We reviewed 55 knees (51 patients: 34 men and 17 women; mean age, 44.2years; range 34–58years) followed up for a minimum 12 months (range, 12–62months). All patients had relief of pain, but six met our criteria of failed treatment where either revision fixation was required or proceeded to total knee arthroplasty for persisting symptoms. Cincinnati scores were 94.5% excellent (52/55) and 5.5% good (3/55) at 1 year, whilst at last follow-up they were 87.2% excellent (48/55), 9.1% good (5/55) and 3.6% fair (2/55). There was a significant improvement in mean American Knee Society score at 1 year and maintained at last follow-up (p< 0.05). Radiographically the lateral hinge was noted to be breached in 9.1% (5/55), but no incidence of non-union was identified. There was no significant change in IS index, however BP index diminished by a mean 15.3% (range, 7.4–28.2%). Opening wedge HTO provides a means of relieving stress distribution through the medial tibiofemoral compartment and results in effective relief of symptoms with improvement in functional outcome and quality of life.

Introduction: We report our experience with use of the SMILES prosthesis in primary knee arthroplasty.

Methods: The Stanmore Modular Individualised Lower Extremity System (SMILES prosthesis) has been shown to be effective in complex revision knee surgery. It incorporates a rotating hinge platform knee joint and can overcome the major problems of bone loss and ligamentous laxity.

38 patients (41 knees) who received a primary SMILES knee prosthesis by one of the senior authors between 1990 and 2006 were retrospectively studied. Knee function was assessed pre and post-operatively using the Oxford knee score (0–48 scoring system) and the Knee Society Score. Patients receiving surgery for tumours were excluded. The main indications for primary SMILES were bone loss and ligamentous laxity.

Results: The minimum follow-up was 18 months with a mean of 5 years (1–17). The mean age of the patients was 57.7 years (23–86); 15 of the patients were male. The indications for surgery were trauma (12), osteoarthritis with deficient medial collateral ligament (8), polio (7), rheumatoid arthritis (5), epiphyseal dysplasia (4), achondroplasia (2), avascular necrosis (1), osteogenesis imperfecta (1) and ankylosing spondylitis (1).

2 patients died and 5 were lost to follow-up. 2 patients required revision surgery (one for infection and one for re-bushing). Post-operative complications included peroneal nerve palsy (1) and DVT (1). The mean Oxford knee score improved from 9 pre-op to 44 post-op, and the mean knee society score improved from 24 pre-op to 71 post-op. The average range of motion was 57 degrees pre-op and 88 degrees post-op.

Conclusion: We conclude that the SMILES prosthesis offers significant improvement in clinician and patient assessed outcome scores in complex primary knee arthroplasty. The cost compares favourably with other designs and its use is well established.

Introduction: Approximately 0.5 % of patients with metal on metal hip replacements develop post operative pain which is thought to be due to an immune reaction to metal wear particles, known as Aseptic Lymphocyte Dominated Vasculitis Associated Lesion (ALVAL). Treatment usually requires revision to a non metal on metal hip.. Is the development of ALVAL more likely in those patients with high wear rates?

Methods: Retrieved Metal on Metal (MOM) hip implants; periprosthetic tissue and blood samples were obtained from patients (n = 18) undergoing revision for unexplained pain at a mean of 2 years post operatively. The following variables were measured:

linear wear rate (depth of the femoral head and acetabular socket wear patch/time from operation);

All implants and tissue samples were analysed against control samples from patients undergoing revision of MOM hips for fractured femoral neck or impingement.

Results: Linear wear rates of retrieved implants, and blood levels of cobalt and chromium from patients with unexplained plain were greater than from control patients. Histolopathological analysis of tissue showed dense inflammatory infiltrates with healthy looking endothelial cells in all vessels from both patient groups.

Discussion and Conclusion: A painful MOM hip was associated with high wear rates and blood metal levels. The local inflammatory response was similar to “ALVAL”, ie lymphocyte dominated, but not exclusive to those patients with unexplained pain. We question whether ALVAL represents a vasculitis, or merely a classical lymphocyte driven inflammatory tissue response to metal debris particles.

Aim: To review the short-term clinical results of a single-institution cohort undergoing opening wedge high tibial osteotomy (HTO).

Method: We undertook a prospective clinical and radiographic review of our cohort of patients who had undergone opening wedge HTO for varus malalignment. The Cincinnati scoring system was used for objective assessment. Pre- and post-operative radiographs were evaluated and Blackburne-Peel (BP) and Insall-Salvati (IS) ratios recorded, as well as integrity of the lateral hinge.

Results: we reviewed 55 knees (51 patients: 34 men and 17 women; mean age, 44.2 years; range 34–58 years) followed up for a minimum 12 months (range, 12–62 months). All patients had relief of pain, but six met our criteria of failed treatment where either revision fixation was required or proceeded to total knee arthroplasty for persisting symptoms. Cincinnati scores were 94.5% excellent (52/55) and 5.5% good (3/55) at 1 year, whilst at last follow-up they were 87.2% excellent (48/55), 9.1% good (5/55) and 3.6% fair (2/55). There was a significant improvement in mean American Knee Society score at 1 year and maintained at last follow-up (p< 0.05). Radiographically the lateral hinge was noted to be breached in 9.1% (5/55), but no incidence of non-union was identified. There was no significant change in IS index, however BP index diminished by a mean 15.3% (range, 7.4–28.2%).

Discussion: Medial opening wedge tibial osteotomy results in patellar infera, but successful clinical and functional outcomes have been demonstrated. The fact there is inconsistency between the two indices assessing patellar height ratio we believe reflects the inherent variability in the techniques employed. Distalisation of the tibial tubercle will mean the IS ratio remains unaffected, whilst the BP index more accurately demonstrates the lowering of patella relative to the joint line. However there may be other factors which are not immediately appreciated, such as changes in the tibial inclination or antero-posterior translation.

Autologous chondrocyte implantation is an option in the treatment of full-thickness chondral or osteochondral injuries which are symptomatic. The goal of surgery and rehabilitation is the replacement of damaged cartilage with hyaline or hyaline-like cartilage, producing improved levels of function and preventing early osteoarthritis. The intermediate results have been promising in terms of functional and clinical improvement.

Our aim was to explore the hypothesis that the histological quality of the repair tissue formed after autologous chondrocyte implantation improved with increasing time after implantation.

In all, 248 patients who had undergone autologous chondrocyte implantation had biopsies taken of the repair tissue which then underwent histological grading. Statistical analysis suggested that with doubling of the time after implantation the likelihood of a favourable histological outcome was increased by more than fourfold (p < 0.001).

Introduction: Blood management in the perioperative period of the total joint arthroplasty procedure has evolved over the last 3 decades. We performed two separate studies:

1) observational study to analyse surgeon’s and anaesthetist’s attitude to transfusion

Method: 500 orthopaedic surgeons and 336 anaesthetists were surveyed to assess current UK attitudes towards transfusion practice following arthroplasty.

200 patients (88 THR, 99 TKR, 13 hip resurfacing) were evaluated. Blood Hb, hand grip strength and vigour scores using fatigue questionnaire were estimated both preoperatively and at 3 days following surgery. POMS and the required duration of in-patient physiotherapy were also noted. The protocol for blood transfusion was for those with Hb less than 8 g/dL and/or post-operative symptoms attributable to anaemia.

Results: In an uncomplicated patient following total hip arthroplasty, 53.2% of surgeons and 63.1% of anaesthetists would transfuse at or below Hb of 8g/dL. Mean transfusion threshold in surgeons was 8.3g/dL compared to 7.9g/dL for anaesthetists (p< 0.01). 97% of surgeons transfused two or more units compared to 78% anaesthetists (p< 0.01). This threshold Hb increased if patient was symptomatic (surgeons 9.3g/dL, anaesthetists 8.8g/dL, p< 0.05), or if known to have pre-existing ischaemic heart disease (surgeons 9.0g/dL, anaesthetists 9.2g/dL, p< 0.05).

A greater fall in postoperative Hb correlated significantly with a greater reduction in post-operative vigour score (p=0.02). Also a greater fall in vigour score was found to correlate significantly with the duration of in-patient physiotherapy (p< 0.001). A reduction in Hb of > 4g/dL from the pre-operative Hb predicted a significantly higher reduction in vigour score (p=0.03). A weak correlation was seen between a fall in Hb and POMS (p=0.09).

A higher pre-operative Hb did not reduce the required duration of in-patient physiotherapy (p=0.72). There was no correlation between post-operative Hb and POMS (p=0.21) or duration of in-patient physiotherapy (p=0.20).

A higher pre-operative grip strength predicted an early date of discharge by the physiotherapists (p=0.02).

Conclusion: Haemoglobin level below 9g/dL is the most common ‘trigger’ for blood transfusion. Surgeons tend to be more aggressive in their attitude to transfusion. A fall in Hb of more than 4 g/dL has a detrimental effect on post-operative rehabilitation. Pre-operative grip strength measurements are valuable in predicting the rehabilitation potential of patients undergoing lower limb arthroplasty.

Introduction and aim: We have previously shown an association between whole blood metal ions and reduced CD8+ T cells in patients with unilateral metal on metal (MOM) hip resurfacings. Our aim was to substantiate this controversial finding with a follow up cohort of larger numbers of patients before further immunological investigation.

Method: We measured lymphocyte subset counts and whole blood Cobalt and Chromium in 2 groups of patients: a Birmingham hip resurfacing group (n=100); and a metal on polyethylene MOP hip arthroplasty group (n=34). Metal ions were measured using inductively-coupled mass spectrometry (ICP-MS) with a Dynamic Reaction Cell (DRC). The detection limit was 10 parts per trillion. All hip components were well fixed, clinically and radiologically.

Results: Cobalt and chromium levels were significantly elevated in the MOM resurfacing group compared to the MOP group (p< 0.0001). There was a statistically significant decrease in the MOM resurfacing groups’ level of CD8+cells (T cytotoxic) (p=0.005) when analysed by a Mann-Whitney U test. There was no significant difference between levels of CD4+ (T helper cells), CD19+ (B cells) and CD16/56+ (Natural Killer cells). A threshold level of blood cobalt and chromium ions for depression of total numbers CD8+ T cells was observed.

Conclusions: This follow up cohort of 100 MOM hip resurfacing patients has replicated the association of reduced CD8+ T cells and raised metal ion levels observed in our founder cohort. This was specific to CD8+ T cells. We are now more certain that this association needs further detailed immunological investigation.

Introduction: Smoking is associated with impaired wound healing, delayed bony union following fractures and an adverse effect on the immune system. Furthermore, smoking is an important risk factor for the development pulmonary complications following major surgical procedures, as well as wound complications. We determined whether smoking had a deleterious effect on outcome after autologous chondrocyte implantation (ACI) in the treatment of ostechondral defects of the knee.

Methods: We identified 103 (54 females and 49 males) patients with a mean age of 34.2 (range 18 to 49) who had undergone ACI between January 2001 and August 2004 who also had their smoking status recorded. The patients were divided into 3 groups according to their smoking status. The Visual Analogue Score, Bentley Functional Rating Score and Modified Cincinatti Scores were used to assess function pre-operatively, 6 months and then yearly thereafter.

Results: Group 1 consisted of 31 smokers (mean pack years of 13.4), group 2 consisted of 63 non-smokers and group 3 contained 9 ex-smokers. In Group 1, the Modified Cincinatti Score pre-operatively, 6 months, 1 year and 2 years following surgery were 34.1, 42.6, 43.5 and 46.7 respectively. In group 2 the scores were 47.4, 59.6, 59.1, 65.3, and in group 3 the scores were 39.8, 50, 53.3, 51.8. At the 1 year check arthroscopy, the graft failure rate in group 1 was 12% and biopsies revealed mixed hyaline and fibrocartilage in only 25% (there were no patients with hyaline cartilage). There were no graft failures in group 2 and 43.8% of the biopsies performed were either hyaline (12.5%) or mixed hyaline and fibrocartilage (31.3%). The wound complication rate was 24% in group 1 and 8% in group 2.

Conclusions: The results of this study suggest that people who smoke have a worse functional outcome and a higher complication rate following chondrocyte implantation. This association has not been previously described and should be included in the pre-operative counselling of patients undergoing the procedure.

Introduction: Pharmacological and mechanical methods are recommended to prevent venous thromboembolism (VTE) following hip replacement (THR). However, data on mechanical methods such as graduated compressive stockings (GCS) are limited. This study examined the efficacy and safety of GCS when added to fondaparinux.

Methods: The randomised treatments were 2.5 mg fondaparinux for 5–9 days starting postoperatively alone or with GCS for 42±7 days. The primary efficacy outcome was VTE or sudden death prior to Day 42±7. All patients were to have duplex USS at day 42 + 7. VTE was defined by verified symptomatic VTE or asymptomatic proximal DVT. The main safety outcomes were major and minor bleeding and VTE death.

Results: 856 patients were randomised, of which 799 were THR patients. Of these 756 (95%) were evaluable, 377 in the fondaparinux and 379 in the fondaparinux plus GCS groups. Risk factors for thrombosis were recorded (age > 75 in 20%, history of obesity in 21%, cancer in 6% and VTE in 3%). Compliance with GCS was high, with 85% wearing them continuously. The primary efficacy outcome of VTE or sudden death in THR patients was similar in each treatment group, the results were 5.5% in the fondaparinux only group and 5.3% in the fondaparinux with GCS group; odds ratio was 0.96, 95% confidence interval 0.50–1.83, p=0.91. Outcomes were not different for long-length and short-length stockings. Major bleeding occurred in one patient (< 1%), minor bleeding in 6.7%. No VTE deaths were reported.

Discussion: The addition of GCS to fondaparinux showed no benefit in thromboprophylaxis over fondaparinux alone in this large study of THR patients. Therefore GCS may not be indicated in patients receiving fondaparinux. Graduated compression stockings are time consuming to measure and fit, inconvenient and expensive; therefore we recommend a reconsideration of this current and commonly used practice in THR.

Introduction: Several studies have implicated excessive weight as a negative predictor of success of total knee arthroplasty. In addition, obese patients are known to have increased risk of wound complications after orthopaedic and general surgery. The purpose of this study was to compare the clinical and functional outcomes of autologous chondrocyte implantation for treatment of osteochondral defects of the knee performed in obese patients with those performed in non-obese patients.

Methods: We analysed the data on all our patients that have been followed up for a minimum of 2 years and had their height and weight recorded initially in our database. Functional assessment consisted of Bentley Functional Rating Score, Visual Analogue Score, and the Modified Cincinatti Scores (collected prospectively at 6 months, 1 year, 2 years and 3 years following surgery). Patients were placed into 3 groups according to their body mass index (BMI). Group A consisted of patients with BMI of 20 to 24.9, group B patients with BMI of 25 to 29.9 and Group C are patients with BMI of 30 to 39.9.

Results: There were 80 patients (41 males and 39 females) with a mean age of 35.4 (range 18 to 49). The mean BMI for the entire group was 26.6. The pre-operative, 6 month, 1 year, 2 year, and 3 year Modified Cincinatti Score in Group A (32 patients) was 54.4, 80.3, 82.7, 74.7 and 72.6. Similarly in Group B, the scores were 53, 41, 54, 56, 49.5 and in Group C the scores were 36.3, 36.3, 49.6, 36, and 35.7. The wound infection rate in Group A was 6.25%, in Group B was 17.6% and Group C was 14.3%.

Conclusions: Initial results from this study suggest that BMI is an important predictor of outcome after chondrocyte implantation. The group of patients that would gain most benefit from ACI are patients that are not overweight (defined by BMI in the range of 20 to 24.9). Further work is being carried out to support the hypothesis that surgeons should strongly consider not operating on patients unless the BMI is less than 25.

Introduction: We have previously shown an association between whole blood metal particles from unilateral metal on metal (MOM) hip resurfacing and reduced CD8+ T cells (JBJS Br April 2006). There are no reported clinical effects of these findings. Certain patients maybe at high risk of developing clinical effects; one such group is patients with bilateral hip resurfacings. There are no published studies of bilateral hip resurfacings. Our aim was to investigate the association between whole blood metal ions and reduced CD8+ T cells in a follow up cohort of bilateral MOM hip resurfacings.

Method : Peripheral blood samples were analysed from patients with bilateral MOM hip resurfacings (n=25), unilateral hip resurfacings (n=34) and metal on polyethylene (MOP) hip arthroplasty (n=34). Samples were analysed for: lymphocyte subsets (FACS analysis); whole blood cobalt and chromium ion levels (using inductively-coupled mass spectrometry). Xrays revealed all hip components were well fixed.

Results : When compared to patients with standard MOP hip replacements there was a 30% reduction in both the bilateral and unilateral resurfacing groups’ level of CD8+ cells (T cytotoxic) (p=0.010). All other lymphocyte subgroups were not significantly different. There was evidence of a threshold effect of raised metal ions and reduced CD8+ T cells but no evidence of a dose-response relationship.

Conclusions : Bilateral MOM hip resurfacing is associated with a reduced CD8+ T cell count when compared to MOP hip arthroplasty. This association is not significantly different from the levels seen after unilateral MOM hip resurfacing.

Introduction and aim: We have previously shown suppressed levels of CD8+ T lymphocytes in patients with metal-on-metal (MOM) hip resurfacing compared to patients with metal on polyethylene hip replacements. Functional assessment of T lymphocytes may help to determine the importance of this CD8+ reduction following hip resurfacing.

Method: We isolated peripheral blood mononuclear cells (PBMC) from patients with unilateral MOM hip resurfacing (n=7) and healthy controls without hip replacement (n=8). Patients with hip resurfacing had excellent Harris Hip scores (mean 90) and well fixed components on radiographs. Whole blood and serum levels of Cobalt (Co) and Chromium (Cr) ions were measured with Inductively-Coupled Mass Spectrometry. T cell function was assessed by

cell proliferation assays (3H-thymidine incorporation) and

Results: Co and Cr ion levels were significantly elevated in the MOM hip resurfacing group compared to the control group (p< 0.001). Proliferation rates of T cells were comparable between the two groups over one week, but interferon-gamma (IFN-γ) production in the MOM hip resurfacing group was significantly decreased (p < 0.05), when compared to the control group.

Conclusion: IFN-γ is normally produced by CD8+ (T cytotoxic cells) and CD4+ (T helper 1 cells) in response to viral infection and high levels of IFN-γ is associated with autoimmune disease. Raised levels of metal ions from hip resurfacing reduces the production of IFN-γ following stimulation with PHA. This finding has been patented for potential therapeutic use through MRC technology.

Introduction: ACI is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We report the minimum 2 year follow-up results of 192 patients randomised to autologous chondrocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) and matrix-induced autlogous chondrocyte implantation (MACI) for the treatment of osteochondral decfects of the knee.

Methods: 192 patients (mean age 34.2) were randomised to have either ACI (86 patients) or MACI (106 patients). 1 year following surgery patients underwent check arthroscopy (with or without biopsy) to assess the graft. Functional assessment was performed yearly by using the modified Cincinatti knee score, the Bentley functional rating score and the visual analogue score.

Results: 24 patients were excluded from the study as they underwent additional procedures (e.g. high tibial osteotomy). In the ACI group the modified Cincinatti score increased from 42.5 pre-operatively to 56.7, 54.1, and 60.4 at 1 year, 2 years and 3 years respectively. In the MACI group the Cincinatti scores increased from 46.0 pre-operatively to 59.9, 58.9, and 58.4. Arthroscopic assessment showed a good to excellent International Cartilage Repair Society score in 90.7% of ACI-C grafts and 68.4% of MACI grafts. Hyaline-like cartilage or hyaline-like with fibrocartilage was found in biopsies of 51.9% of ACI-C grafts and 25.9% of MACI grafts.

Conclusions: ACI grafts are more likely to produce hyaline-like or mixed hyaline-like cartilage and fibro-cartilage with better ICRS grades than MACI grafts. However, this does not translate to better a clinical functional outcome. More importantly, ACI and MACI had similar results that were maintained at 3 years.

We aimed to determine whether proximal femoral bone remodelling, as measured by DEXA scan for each Gruen Zone, differed for 3 different femoral stem designs. These were:

Group 1 – Triple taper polished (C-stem J& J DePuy)

Ethical Committee approval was obtained and all patients gave informed consent. All operations were performed by 3 surgeons using a standard lateral approach, third generation cementing technique and a standard post-operative regime.

Seventy-five patients were randomised prospectively using a stratified randomisation programme for known risk factors in bone density. The randomisation was stratified by age, sex, Charnley Group (A or B), BMI and femoral neck bone mineral density. There were 25 patients in each Group, 5 patients did not have complete data sets and were therefore withdrawn from evaluation.

The Groups were similar with regard to age, sex, BMI, BMD and Charnley Group. Patients were followed up at 3, 6, 12 and 24 months by Nurse Practitioners for clinical and radiological evaluation and DEXA scan at each time of follow-up. There were no catastrophic failures of sepsis or dislocation. All patients functioned well at 24 months by Harris Hip Score.

The bone remodelling pattern will be described for each stem design. Findings are summarised thus. In the lateral Gruen Zones the triple taper and collared stem design faired better and both behaved differently to the double taper design. In Gruen Zone 7, all stems demonstrated reduced bone density as compared to pre-operative scans but this was less with the triple taper design.

Purposes of Study: To establish what happens, over time, to an ACL graft which is implanted in the skeletally immature knee.

Methods/Results: 5 cases of hamstring ACL reconstruction in prepubertal patients were available from the practices of 2 surgeons in which there were X-ray/MRI images taken over a period of an average of approximately 3 years from the operation. The changes in graft dimensions were measured from these images. No case of growth arrest was seen, nor of soft tissue contracture such as fixed flexion. All patients recovered to their same pre-injury level of activity, including elite level sport in 3 cases. Clinical laxity tests were always satisfactory but the senior authors have noticed that they tighten in time.

The growth of the patients was an average 17cm. The graft diameters did not change despite large changes in graft length (average 145%). Most of the length gain was in the femur.

Conclusion: Much has been written regarding potential harm to the growth plate in these patients but we are not aware of literature on the subject of the fate of the graft itself. Considerable length changes in the grafts were evident. The biological phenomena taking place in the graft are unknown. We have clearly shown an increase in the size of graft tissue due to lengthening but no change in girth. Either the graft stretches or tissue neogenesis occurs, or both. If it simply stretched then the graft would be expected to become narrower, at least in places- it did not. Nevertheless the ‘tightening’ phenomenon reported anecdotally could be due to the graft having to stretch but failing to keep up with growth. As the volume of graft increases so much then at least some neogenesis is highly likely.

Aims: To compare the clinical and functional outcomes of autologous chondrocyte implantation for treatment of osteochondral defects of the knee performed in overweight, obese and patients of ‘ideal weight’as defined by their BMI.

Methods: We analysed the data on all our patients that have been followed up for a minimum of 2 years and had their height and weight recorded initially in our database. Functional assessment consisted of the Modified Cincinatti Scores (collected prospectively at 6 months, 1 year, 2 years and 3 years following surgery). Patients were placed into 3 groups according to their body mass index (BMI). Group A consisted of patients with BMI of 20 to 24.9, group B patients with BMI of 25 to 29.9 and Group C are patients with BMI of 30 to 39.9.

Results: There were 80 patients (41 males and 39 females) with a mean age of 35.4 (range 18 to 49). The mean BMI for the entire group was 26.6. The pre-operative, 6 month, 1 year, 2 year, and 3 year Modified Cin-cinatti Score in Group A (32 patients) was 54.4, 80.3, 82.7, 74.7 and 72.6. Similarly in Group B, the scores were 53, 41, 54, 56, 49.5 and in Group C the scores were 36.3, 36.3, 49.6, 36, and 35.7. The wound infection rate in Group A was 6.25%, in Group B was17.6% and Group C was 14.3%.

Conclusions: Initial results from this study suggest that BMI is an important predictor of outcome after chon-drocyte implantation. The group of patients that would gain most benefit from ACI are patients that are not overweight (defined by BMI in the range of 20 to 24.9). Further work is being carried out to support the hypothesis that surgeons should strongly consider not operating on patients unless the BMI is less than 25.

Aims: To investigate

the influence of histology on durability of cartilage repair following collagen-covered autologous chon-drocyte implantation (ACI-C) in the knee.

Patients and methods: The modified Cincinnati scores (MCRS) of eighty-six patients were evaluated prospectively at one year and at the latest follow-up (mean follow-up = 4.7yrs. Range = 4 to 7 years). Biopsies of their cartilage repair site were stained with Haema-toxylin and Eosin and some with Safranin O and the neo-cartilage was graded as hyaline-like (n=32), mixed fibro-hyaline (n=19) and fibro-cartilagenous tissue (n=35). Macroscopic grading of the repair tissue using the international cartilage repair society grading system (ICRS) was available for fifty-six patients in this study cohort. Statistical analyses were performed to investigate the significance of histology and ICRS grading on MCRS at 1 year and at the latest follow-up.

Results: The MCRS of all three histology groups were comparable at one year evaluation (p=0.34). However, their clinical scores at the latest follow-up showed a significantly superior result for those with hyaline-like repair tissue when compared to those with mixed fibro-hyaline and fibro-cartilagenous repair (p=0.05).

There was no correlation between the ICRS grading and MCRS either at one year (p=0.12) or at the latest follow-up (p=0.16). Also, the ICRS grading of the repair tissue did not correlate with its histological type (p=0.12).

Conclusion: We conclude that any form of cartilage repair gives good clinical outcome at one year. At four years and beyond, hyaline-like repair tissue produces a more favourable clinical outcome. Macroscopic evaluation using the ICRS grading system does not reflect the clinical outcome or its durability or the histological type of repair tissue.

Objective: To investigate the possible effects of preop-erative Neuromuscular Electrical Stimulation (NMES) to the quadriceps and hamstrings for the patients undergoing Total Knee Replacement (TKR) during the immediate postoperative period. Design: Prospective, randomised controlled study. Participants: 36 patients with osteoarthritis(OA) of the knee who were waiting for the elective TKR were randomly assigned to 1 of 2 groups (18 per group): control and study group. The study group patients received NMES to the quadriceps and hamstrings preoperatively. One patient in the control group and five patients in the study group were excluded due to the following reasons: operation postponed (two), unicompartmental knee replacement was performed (one), patients not willing to continue to use NMES due to personal reasons (two) and inappropriate/unable to use NMES (one). Both the control and the study group patients received standard physiotherapy postoperatively. Intervention: NMES (100Hz frequency; 0 to 55 volts amplitude; 1 second on/1 second off stimulation protocol) to the quadriceps and hamstrings muscle groups for 3 to 6 weeks preopera-tively. Amplitude adjustments and usage timings were made by patients (at home) as dictated by the comfort level. Main outcome measures: Immediate postoperative assessment of straight leg raise, stair walking, flexion of knee, pain, walking distance, length of stay for rehabilitation and total length of hospital stay. Limitations: Small number of participants and only early followups were performed. Results: The outcome data suggest a possible benefit, but did not reach statistical significance in all but one parameter, early stair walking.

Purpose: We report on minimum 2 year follow-up results of 71 patients randomised to autologous chon-drocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the knee.

Introduction: ACI is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autolo-gous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes.

Results: 71 patients with a mean age of 33 years (15–48) were randomised to undergo either an ACI-C or a MACI. 37 had ACI-C and 34 MACI. The mean size of the defect was 5.0cm2. Mean duration of symptoms was 104.4 months (9–456). Mean follow-up was 33.5 months (24–45). Functional assessment using the modified Cincinnati knee score, the Bentley functional rating score and the visual analogue score was carried out. Assessment using the modified Cincinnati knee score showed a good to excellent result in 57.1% of patients followed up at 2 years, and 65.2% at 3 years in the ACI-C group; and 63.6% of patients at 2 years, and 64% at 3 years in the MACI group. Arthroscopic assessments showed a good to excellent International Cartilage Repair Society score in 81.8% of ACI-C grafts (22 patients) and 50% of MACI grafts (6 patients). Fisher’s exact test showed a p value of p=0.35 (not statistically significant). Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in biopsies of 56.3% of the ACI-C grafts (9 out of 16 patients) and 30% of the MACI grafts (3 out of 10 patients) after 2 years. Fisher’s exact test showed a p value of p=0.25 (not statistically significant).

Conclusion: At this stage of the trial we conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI.

Introduction: There have been 70,000 hip resurfacings implanted, predictions are for it to become 12% of the US hip replacement market by 2010 (Goldmann Sachs report Oct 2005). There is concern that the cobalt and chromium ions released from metal on polyethylene hip replacements cause immune dysfunction in the form of T cell mediated hypersensitivity (indicated by increased numbers and stimulation of T cells). If metal ions cause significant effects on white blood cells we might reasonably expect to detect this by simply measuring numbers of white blood cells.

Aim : To examine the possibility that raised metal ions may cause an abnormal number of white blood cells, termed a blood dyscrasia.

Method : Peripheral blood samples were analysed from 68 patients: 34 in the hip resurfacing group and 34 in the standard hip arthroplasty group. Samples were analysed for counts of each sub-group of lymphocyte. Functional assessment was also performed using a activation panel of white cell CD markers. Whole blood cobalt and chromium ion levels were measured using inductively-coupled mass spectrometry. All hip components were well fixed.

Results : Cobalt and chromium levels were significantly elevated in the resurfacing group compared to the hybrid group (p< 0.001). There was a statistically significant decrease in the resurfacing groups’ level of CD8⁺ cells (T cytotoxic/suppressor) (p=0.010). There was a characteristic pattern of immune modulation seen on the activation panel.

Conclusions : We found an immune modulation in patients with metal on metal hip resurfacing. This was not a hypersensitivity reaction. This change in T cell function may be detrimental or beneficial to patients.

Introduction and Aims: Allogenic blood transfusion is often required in lower-limb arthroplasty. The aims of this study were (1) to analyze the influence of anaemia on post-operative fatigue, hand grip strength, duration of in-patient physiotherapy and post-operative morbidity score (POMS) and (2) to investigate for prognostic factors to predict functional recovery following primary arthroplasty of the lower limb.

Patients and methods: This study was approved by the regional ethics committee. Two hundred patients (88 THR, 99 TKR and 13 hip resurfacing) were evaluated in this prospective trial. Blood haemoglobin concentration (Hb), hand grip strength and vigour scores using a validated fatigue questionnaire were estimated both preoperatively and at 3 days following surgery. Postoperative morbidity score (POMS) and the required duration of in-patient physiotherapy were also noted. The protocol for blood transfusion was for those with Hb less than 8 g/dL and/or post-operative symptoms attributable to anaemia.

Results: A greater fall in postoperative Hb correlated significantly with a greater reduction in post-operative vigour score (p=0.02). Also a greater fall in vigour score was found to correlate significantly with the duration of in-patient physiotherapy (p< 0.001). A reduction in Hb of > 4g/dL from the pre-operative Hb predicted a significantly higher reduction in vigour score (p=0.03). A weak correlation was seen between a fall in Hb and POMS (p=0.09).

A higher pre-operative Hb did not reduce the required duration of in-patient physiotherapy (p=0.72). There was no correlation between post-operative Hb and POMS (p=0.21) or required duration of in-patient physiotherapy (p=0.20).

A higher pre-operative grip strength predicted an early date of discharge by the physiotherapists (p=0.02).

Conclusion: We conclude that a fall in Hb of more than 4 g/dL has a detrimental effect on post-operative rehabilitation. Pre-operative grip strength measurements are valuable in predicting the rehabilitation potential of patients undergoing lower limb arthroplasty.

Purpose: We report a series of 58 patients with metastatic bone disease treated with resection and endoprosthetic reconstruction over a 5 year period at our institution.

Introduction: The recent advances in adjuvant and neo-adjuvant therapy in cancer treatment has resulted in improved prognosis of patients with bone metastases. Most patients who have an actual or impending pathological fracture should have operative stabilisation or reconstruction. According to BOA guidelines patients should undergo a single procedure which allows early full weight bearing and lasts the expected lifespan of the patient. The use of modern modular endoprostheses allows these criteria to be met.

Methods and Results: We retrospectively identified all patients diagnosed with metastatic disease to bone between 1999 to 2003. 171 patients were diagnosed with bone metastases. Metastatic breast and renal cancer accounted for 47% of the lesions. 58 patients with bone metastasis to the appendicular skeleton had an endo-prosthetic reconstruction. There were 28 males and 30 females. 11 patients had lesions in the upper extremity and 47 patients had lesions in the lower extremity. Mean age at presentation was 62 years (24 to 88 years). 19 patients are still alive, 34 patients had died and 5 were lost to follow-up. Patients died of disease at a mean of 22 months (2 to 51 months) from surgery. Mean follow-up was 55 months (24 to 78 months). There were 5 wound infections, 1 aseptic loosening, 3 dislocations, 1 subluxation and 1 prosthesis rotated requiring open repositioning. Patients were followed up and evaluated using the Musculoskeletal Society Tumour Score (MSTS) and the Toronto Extremity Salvage Score. The mean MSTS score was 73% (57 to 90%) and TESS was 71% (84 to 95%).

Conclusions: We conclude that endoprosthetic replacement for the treatment of bone metastases in selected cases achieves the aims of restoring function, allowing early weight bearing and alleviating pain. The complication rate is low.

Introduction: Since 1975, 6 types of extendable endo-prostheses have been developed at Biomedical Engineering, UCL, and Stanmore Implants Worldwide in conjunction with the surgeons at this centre.

Aims: To establish whether developments in design have had the desired effect of improving both implant survivorship and functional outcome.

Methods: This was a retrospective study using case notes, hospital databases and a radiological review, combined with contemporary functional outcome assessments (MSTS, TESS, SF36).

Results: 161 consecutive prostheses in 138 paediatric patients, between the years of 1983 – 2005, were implanted for primary bone tumours. Mean age was 10.3 (3 – 18), 81 were males and 57 females. There were 136 primary procedures and 25 revisions.

6 prostheses that used ball bearings to achieve length (designed in 1981) were implanted, 3 (50 %) were revised due to mechanical failure.

19 prostheses that utilised external C-washes (1998) to achieve length were implanted, 6 (32 %) were revised, half of these for mechanical failure.

Of the 98 minimally invasive prostheses (1992) that utilized an Allan key and screw-jack mechanism to lengthen, 14 (14 %) were revised, half of these for infection.

17 non-invasive extendable endoprostheses (2001) that are lengthened by electromagnetic coupling have been implanted so far. There has only been 1 (6 %) revision. This was due to full extension being reached.

Conclusions: Design improvements in growing endoprostheses since 1983 have led to improved survivorship. Initially this led to a reduction in mechanical failure and latterly to a reduction in infection, as indications for revision.

Key Words: Bone tumour, children, endoprosthesis, survivorship.

Purpose: We report a series of patients with malignant tumours of the pelvis that had a tissue expander inserted in the pelvis to facilitate radical radiotherapy, and report functional outcomes following treatment.

Introduction: Surgery for malignant tumours affecting the pelvis is challenging. Some tumours are suitable for internal hemipelvectomy and reconstruction, some require hindquarter amputation and some are inoperable. Overall prognosis is poor with high morbidity and mortality rates. There may be a place for alternative treatment with the insertion of pelvic spacers to facilitate radical radiotherapy. This is indicated in patients who have an inoperable tumour, who decline amputation, or who had an internal hemipelvectomy with close margins and high risk of local recurrence.

Methods & Results: We performed a retrospective review of all patients who presented with a malignant tumour of the pelvis and who underwent an insertion of a pelvic spacer followed by local high dose radiotherapy. Available patients were followed up and evaluated using the Musculoskeletal Society Tumour Score (MSTS) and the Toronto Extremity Salvage Score (TESS). There were ten patients; 5 had Ewing’s sarcoma, 3 had osteosarcoma, 1 had spindle cell sarcoma and 1 had alveolar soft part sarcoma. 4 patients had metastases on presentation. The average age was 30 years (14 to 56 years), and average follow-up was 15 months (12 to 24 months). 4 patients died and 6 are still alive. There were no surgical complications. The average length of hospital stay was 6 days (2 to 10 days). Patients averaged an MSTS score of 63% and a TESS of 67%.

Conclusion: Radical radiotherapy after spacer insertion offers an alternative to morbid surgery and is associated with good functional outcomes.

Aim: The aim of this study was to correlate the histology of cartilage repair site with long term clinical function.

Materials and methods: We have analyzed the clinical results of a cohort of patients who had collagen-covered autologous chondrocyte implantations performed since 1998. Our hypothesis was that the hyaline cartilage repair does influence the clinical outcome.

The modified Cincinnati scores (MCRS) of eighty-six patients were evaluated prospectively at one year and at the latest follow-up following ACI-C (mean follow-up= 4.7 years. Range= 4 to 7 years). All these patients underwent biopsies of their cartilage repair site performed at variable periods between six months and five years following ACI-C (mean=22.2 months). The neo-cartilage was graded as hyaline (n=32), mixed fibrohyaline (n=19), fibrocartilagenous (n=35) and fibrous (n=0).

Results: The clinical results showed that at one year, the percentage of patients with excellent and good results was 84.4, 89.5 and 74.3 respectively for those with hyaline, mixed fibro-hyaline and fibro-cartilagenous histology respectively. Their mean MCRS were 70.8, 72.4 and 66.2 respectively. This difference was not statistically significant (p=0.34).

However, their clinical scores at the latest follow-up demonstrated a significantly superior result for those with hyaline repair tissue when compared to those with mixed fibro-hyaline and fibro-cartilagenous repair tissue (p=0.05). The percentage of patients with excellent and good results for those with hyaline, mixed fibro-hyaline and fibro-cartilagenous repair was 75, 42 and 68.6 respectively. Their mean MCRS were 70.6, 56.8 and 63.9 respectively.

Conclusion: This study demonstrates that any form of cartilage repair would give good clinical outcome at one year. At four years and beyond, it appears that patients with hyaline repair tissue tend to show a more favourable clinical outcome whereas those who demonstrated mixed fibrohyaline and fibrocartilagenous repair would show less favourable clinical results.

Background: Metal-on-metal bearing hip replacements release between three and nine times more cobalt and chromium ions than a metal on polyethylene bearing hip replacement. We do not fully understand the cause for the variability of ion levels after metal on metal hip replacement. The factors that determine an individual’s levels of metal ions include: firstly, patient factors (renal failure, patient weight, high activity); secondly, manufacture factors (head size (and fluid film lubrication), carbide density, surface finish) and lastly study factors (bilateral implants, time from operation). Biomechanical studies suggest that component position, in particular acetabular inclination, is important for wear rate but there is no published correlation from clinical studies.

Aim: To investigate the relationship between acetabular inclination angle and metal ion levels of patients with Birmingham Hip resurfacings.

Methods: Using standardised radiographs, we measured the inclination angle (using UTHSCSA image tool) of the acetabular components in thirty-one patients (mean age 54 years) who underwent unilateral Birmingham hip resurfacing (mean time post operation of 22 months). We also measured peripheral whole blood chromium and cobalt ion concentrations using inductively coupled mass spectrometry. All components were well fixed.

Results: There was a positive correlation between the inclination angle (range 28 degrees – 55 degrees) of the acetabular component and whole blood concentration of Cobalt (range 2.3 – 7 mcg/L), Chromium (range 0.56 – 4.3 mcg/L) and total metal ion levels (range 3.1 – 10.3 mcg/L). This finding was statistically significant, with a Pearson correlation coefficient of 0.46 (95% CI 0.13-0.70) and a p-value of 0.00398.

Conclusion: Acetabular inclination angle is likely to be a factor in determining an individual’s metal ion levels in patients with metal on metal resurfacing. We also iden-tified a threshold level of 50 degrees inclination, after which the metal ion levels rise dramatically. We describe the possible biomechanical mechanisms to explain these results. We recommend surgeons implant the metal socket at an inclination angle of less than 50 degrees.

Background: Extra-compartmental limb soft tissue sarcomas are notoriously difficult to treat. These tumours can exhibit macro or microscopic spread beyond the confines of normal anatomical barriers and require radical resection, often necessitating excision of bone as well as soft tissue. This will inevitably affect the patient’s functional outcome. The primary operations for these aggressive sarcomas include wide local excision of soft tissue and adjacent involved bone, radical resection with endoprosthetic reconstruction and amputation.

Methods: 85 patients who underwent such an operation between 1995 to 2000 were reviewed and categorised according to whether they received wide local excision, endoprosthesis reconstruction or amputation. Patient demographics, sarcoma details, recurrence and survival rates were identified and compared between the three groups. Functional outcomes in the 45 patients still alive were assessed using TESS and MSTS scores.

Results: Mean age was 61 years (range 8 to 92). There were 51 males and 34 females. Anatomical distribution was as follows: arm 26, leg 47, pelvis 8 and other 4. The commonest histology subtypes were MFH, leiomyosarcoma and undifferentiated soft tissue sarcoma. 17 had wide local excision of bone and soft tissue, 32 underwent endoprosthesis reconstruction and 36 underwent primary amputation. Recurrence rates were highest in the endoprosthesis group at 19%. Five year survival was worst in the amputation group at 49%. Functional outcomes were highest in the wide local excision group, and similar in the other two surgical groups.

Conclusions: Unsurprisingly survival is poorest in the primary amputee group because of the highly aggressive nature of these sarcomas, despite having the most radical treatment. The similar functional outcomes shown between endoprosthesis reconstruction and primary amputation may be influential when considering cases in which this decision is unclear and function is the main issue at stake.

Purpose: We report the clinical and functional outcome of limb salvage surgery and endoprosthetic reconstruction of the distal tibia and ankle joint in 5 patients.

Introduction: The distal tibia is an uncommon site for primary malignant bone tumours and the treatment of choice for most patients is a below knee amputation. Patients who decline an amputation may be offered an endoprosthetic replacement. This is a technically challenging operation and may be associated with high morbidity.

Methods and Results: Over 25 years at our centre, 5 patients underwent distal tibial replacements for bone or soft tissue sarcomas. Two had osteosarcoma, one had a recurrence of Ewing’s sarcoma, one had malignant fibrous histiocytoma, and one had an adamantinoma. The mean age was 37 years (13 to 69 years). There were no tumour recurrences. Four patients developed complications with wound infection. Two of these resulted in below knee amputations. Average follow-up was 31 months (19 to 55 months) with 1 patient lost to follow-up. Patients were evaluated using the Toronto Extremity Salvage Score (TESS) and the Musculoskeletal Tumour Society (MSTS) score. The mean MSTS score was 88% and the mean TESS was 88.5%. Two patients who later had a below knee amputation and who were using a prosthesis averaged an MSTS score of 86.3% and a TESS of 89.3%.

Conclusion: For those patients who are unwilling to undergo an amputation for malignant tumours of the distal tibia, endoprosthetic reconstruction is an alternative, but at the cost of increased risk of significant complications, functional deterioration and morbidity. There was little difference between functional scores for patients who proceeded to have a below knee amputation compared to patients who still had their endoprosthesis

The potential harm to the growth plate following reconstruction of the anterior cruciate ligament in skeletally-immature patients is well documented, but we are not aware of literature on the subject of the fate of the graft itself. We have reviewed five adolescent males who underwent reconstruction of the ligament with four-strand hamstring grafts using MR images taken at a mean of 34.6 months (18 to 58) from the time of operation. The changes in dimension of the graft were measured and compared with those taken at the original operation. No growth arrest was seen on radiological or clinical measurement of leg-length discrepancy, nor was there any soft-tissue contracture. All the patients regained their pre-injury level of activity, including elite-level sport in three. The patients grew by a mean of 17.3 cm (14 to 24). The diameter of the grafts did not change despite large increases in length (mean 42%; 33% to 57%). Most of the gain in length was on the femoral side. Large changes in the length of the grafts were seen.

There is a considerable increase in the size of the graft, so some neogenesis must occur; the graft must grow.

Introduction: Autologous chondrocyte implantation (ACI) is a technique described for treating symptomatic osteochondral defects in the knee. It is contra-indicated, however, in a joint rendered unstable by a ruptured anterior cruciate ligament (ACL). We present our early experience of combined ACL and ACI repair.

Methods: Patients underwent arthroscopic examination and cartilage harvesting of the knee. Chondrocytes were then cultured in plasma and a second operation was undertaken approximately four weeks later to repair the ruptured ACL with hamstring graft and to implant the chondrocytes via formal arthrotomy. Patients then underwent a graduated rehabilitation program and were reviewed at 6 and 12 months. Functional measurements were made using the Bentley functional scale and the modified Cincinnati rating system, with pain measured on a visual analogue scale. All patients also underwent formal clinical examination at each review.

Results: 4 out of the 5 patients reported an improvement in pain as measured on visual analogue scale, with 1 patient reporting no difference. 4 patients had stable knees as determined by negative anterior draw, negative Lachman’s test and negative pivot shift test; one patient showed improvement, but remained pivot shift positive. Improvements in Bentley scores were noted in 3 patients. Cincinnati scores were markedly improved in 3 patients and slightly improved in the remaining 2 patients. The only operative complications were a traction neuropraxia to the saphenous nerve of one patient requiring no treatment and a manipulation under anaesthesia for poor mobilisation in another patient, which was successful in improving range of movement. A further patient required arthroscopic trimming of the cartilage graft which had overgrown; this was also successful.

Conclusion: Symptomatic cartilage defects and ACL deficiency may co-exist in many patients and represent a treatment challenge. Our early results suggest that a combined ACL and ACI repair is a viable option in this group of patients and should reduce the anaesthetic and operative risks of a two-stage repair. More patients and longer follow up will be required to fully assess this technique.

We used a knee-sparing distal femoral endoprosthesis in young patients with malignant bone tumours of the distal femur in whom it was possible to resect the tumour and to preserve the distal femoral condyles. The proximal shaft of the endoprosthesis had a coated hydroxyapatite collar, while the distal end had hydroxyapatite-coated extracortical plates to secure it to the small residual femoral condylar fragment. We reviewed the preliminary results of this endoprosthesis in eight patients with primary bone tumours of the distal femur. Their mean age at surgery was 17.years (14 to 21). The mean follow-up was 24 months (20 to 31). At final follow-up the mean flexion at the knee was 102° (20° to 120°) and the mean Musculoskeletal Tumour Society score was 80% (57% to 96.7%).

There was excellent osteointegration at the prosthesis-proximal bone interface with formation of new bone around the hydroxyapatite collar. The prosthesis allowed preservation of the knee and achieved a good functional result. Formation of new bone and remodelling at the interface make the implant more secure. Further follow-up is required to determine the long-term structural integrity of the prosthesis.

Purpose: The purpose of this study was to use the thromboelastogram to determine whether autologous blood transfusion following primary total knee replacement surgery results in an alteration to systemic coagulation.

Methods: 44 patients were randomised to receive either Hartmann’s solution alone postoperatively (control group), or Hartmann’s solution and autologous blood at six hours (ABT group). Thromboelastogram measurements of systemic blood clotting were performed pre-operatively, and post operatively at 6h just prior to the commencement of the ABT, 6h 30mins, and 8h.

Results: At 8h post operation (2h post ABT), the ABT group when compared with the control group showed an earlier onset of coagulation (3.83 minutes versus 4.49 minutes, p=0.003) and the formation of a stronger clot as assessed by the TEG maximum amplitude (maximum clot strength 83.9mm versus 75.9mm, p< 0.001).

Conclusion: The transfusion of drained autologous blood following total knee replacement may lead to an exaggerated hypercoagulable postoperative state. Further investigation of this potentially serious consequence of autologous blood transfusion is required.

We have studied the relationship between metal ion levels and lymphocyte counts in patients with metal-on-metal hip resurfacings. Peripheral blood samples were analysed for lymphocyte subtypes and whole blood cobalt and chromium ion levels in 68 patients (34 with metal-on-metal hip resurfacings and 34 with standard metal-on-polyethylene total hip replacements). All hip components were radiologically well-fixed and the patients were asymptomatic. Cobalt and chromium levels were significantly elevated in the patients with metal-on-metal hip resurfacings, compared with the patients with standard metal-on-polyethylene designs (p < 0.0001). There was a statistically significant decrease in the level of CD8⁺ cells (T-cytotoxic/suppressor) (p = 0.005) in the metal-on-metal hip resurfacing group. A threshold level of blood cobalt and chromium ions was associated with reduced CD8⁺ T-cell counts. We have no evidence that our patients suffered as a result of this reduced level of CD8⁺ T-cells.

Background: Autologous chondrocyte implantation (ACI) was introduced over 15 years ago as a treatment for full-thickness chondral defects in the knee. Current understanding of ACI graft morphology and maturation in humans is limited. The aims of this study were determine the incidence of hyaline-like repair following ACI, and to clarify the relationship between repair morphology and clinical outcome.

Methods: A retrospective review of 194 ACI graft biopsies from 180 patients, and their clinical outcome was conducted. 154 Biopsies were performed 1 year after implantation and 40 biopsies were performed at 2 years. Three techniques of ACI implantation were used; Collagen covered ACI (ACI-C), periosteum covered ACI (ACI-P) and Matrix-Induced ACI (MACI).

Results: At 1 year, hyaline repair tissue was found in 48 (53%) ACI-C grafts, 7 (44%) ACI-P grafts, and 12 (36%) MACI grafts. The frequency of hyaline tissue found in biopsies performed at 2 years (84%) was significantly higher than those performed at 1 year (48.6%), p=0.0001, suggesting that grafts continue to remodel after the first year post implantation.

Clinical outcomes during the first two postoperative years did not vary according to repair morphology type, though hyaline repair was associated with better clinical outcomes beyond 2 years; At 1 year, good to excellent clinical scores were observed in 29 (78.4%) patients with hyaline-like repair, 23 (76.7%) patients with fibrohyaline repair, and 54 (74.0%) patients with fibrocartilage repair. By years 3 and 4 post-implantation, clinical scores further improved in patients with hyaline-like repair yet declined in those with fibrocartilage and fibrohyaline. The difference was significant at 3 years though not at 4 due to the small number of cases.

Conclusions: Achieving hyaline-like repair is critical to the longevity of cartilage repair. The finding of hyaline-like cartilage or fibrohyaline cartilage in 31 of 37 biopsies (84%) performed after 2 years is therefore encouraging and supports further use of the ACI technique.

Background: Autologous Chondrocyte Implantation (ACI) is widely used as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum cover technique include the use of porcine-derived type I/III collagen as a cover (ACI-C), and the use of a collagen bilayer seeded with chondrocytes (MACI).

Aim: To determine whether differences in clinical, arthroscopic and histological outcomes at 1 year exist between ACI-C and MACI techniques.

Methods: We have performed a prospective randomised comparison of ACI-C versus MACI for the treatment of symptomatic chondral defects of the knee on 91 patients of whom 44 received ACI-C and 47 received MACI grafts.

Results: Both treatments resulted in improvements of clinical scores after 1 year. Mean modified Cincinnati knee scores increased by 17.5 in the ACI-C group and 19.6 in the MACI group (p> 0.05). Arthroscopic assessments performed after 1 year demonstrated good to excellent ICRS graft repair scores in 79% of ACI-C grafts and 67% of MACI grafts. Hyaline-like or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43% of ACI-C grafts and 36% of MACI grafts after 1 year. The rate of graft hypertrophy was 9% in the ACI-C group and 6% in the MACI group. The frequency of re-operation was 9% in each group.

Conclusions: We conclude that clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI techniques. While the MACI technique is technically attractive, further long-term studies are required before widespread adoption of this new technique.

We prospectively randomised 104 consecutive patients undergoing primary cemented total knee arthroplasty to receive either a standard suction drain© (Redivac) or autologous transfusion drain® (Bellovac). There were fifty two patients in each group. Randomisation was performed using a software program (Minim) which set to stratify patients based on their age, sex and body mass index (BMI). All procedures were performed under pneumatic tourniquet.

Drains were released in recovery room 20 minutes after surgery and were removed 24 hours following surgery. Blood collected in the standard suction drain was discarded but blood collected in the autologous transfusion drains was transfused unwashed to the patient within six hours of collection.

13 patients (25%) in the study group had two or more units of homologous blood transfused in addition to the blood collected postoperatively and re-transfused (Average= 438mls). 12 patients (23%) in the control group had two or more units of homologous blood transfused. No sepsis, transfusion reactions, or coagulopathies were associated with the autologous blood re-transfused in the study group.

The use of autologous transfusion system (Bellovac) proved to be safe but failed to reduce the need for postoperative homologous blood transfusion following uncomplicated total knee arthroplasty.

Introduction and Aims: ACI (autologous chondrocyte implantation) using a periosteum cover was developed by Peterson et al. Recently, the technique has been developed using a Type I/Type III collagen membrane (Chondro-Gide). A second technique MACI (matrix-induced autologous chondrocyte implantation) has evolved using a membrane with chondrocytes seeded onto its surface. Aim is to review the one and two-year results of the first 159 patients at a single regional centre.

Method: The two-stage procedure was performed with a standardised, progressive rehabilitation program. Patients were assessed clinically at three, six, nine, 12 and 24 months (pain score, Modified Cincinnati, Bentley), and arthroscopically at 12 and 24 months.

Results: 159 patients have been assessed at one year and 101 patients at two years. Of those patients reviewed at one year, 110 patients had the ACI repair with Chondro-Gide, 31 patients had the ACI repair with periosteum and 18 patients had the MACI repair. Sixty-nine percent had good or excellent results at one year and 60% at two years.

These figures represent the early results of this study performed at this unit.

Conclusion: We propose that the ACI technique is valuable for selected patients with Chondral and osteochondral defects of the knee even with large and multiple defects in the articular cartilage.

Introduction and Aims: Uni-compartmental knee arthroplasty (UKA) is appropriate for one in three osteoarthritic knees requiring replacement. An accelerated protocol enables patients undergoing UKA to be discharged within 24 hours of surgery. Before such an approach is universally accepted it must be safe, effective and economically viable. A study was performed to compare the new accelerated protocol with current standard care in a state healthcare system.

Method: A single blind RCT design was used. Patients eligible for UKA were screened for NSAID tolerance, social circumstances and geographical location before allocation to either an accelerated recovery group (Group A) or a standard non-accelerated group (Group S). The accelerated protocol included dedicated pain management and discharge support. Primary outcome was the Oxford Knee Assessment at six months post-operation, compared using independent t tests. Pain, range of movement and incidence of complications were also recorded by assessors blind to group allocation. Cost effectiveness was calculated in quality life adjusted years (QLAY) using the Euroqual instrument. The study power was sufficient to avoid type 2 errors. The study was supported by a NHS Regional R& D grant.

Results: Forty-one patients (21 group A, 20 group S) were included. Groups had comparable age and patient profiles. Average discharge time was 37 hours (1.5 days) for group A and 114 hours (4.3 days) for group S. Pain on hospital discharge was similar for both groups. No significant difference was found between groups for pain or range of movement at any time, although patients in group S regained pre-operative flexion faster than group A. One major complication occurred in each group; one infection (group S) and one manipulation for poor movement (group A). The cost per QLAY for the new protocol was 59% of the standard care.

Conclusion: The new protocol allows for safe accelerated discharge from hospital after UKA. The approach is cost-effective and should help to increase the throughput of patients who require knee replacement.

Aims: The objective of this study was to clinically assess the outcome of CADCAM femoral components in the revision hip replacement. Methods: Between 1991 and 2000, 125 revision total hip replacements using CAD-CAM femoral components were performed. Clinical assessment was performed using the Harris Hip score, by direct patient consultation, and telephone or postal questionnaire. Survivorship was defined as the requirement for revision. Results: The patients were reviewed at a mean of 5.2 yrs (1 to 10)

The mean Harris hip score increased from 44 points (range, 27 to 71 points) preoperatively to 71 points (range, 21 to 98 points) at the time of the most recent follow-up. 9 patients required subsequent revision; 4 for aseptic loosening, 1 for septic loosening and 4 for fracture of the femoral component. Conclusions: CAD-CAM technology provides a viable alternative to the challenge of revision hip surgery, with results comparable to other cementless techniques.