Bone tissue experiences continued remodelling in response to changes in its biochemical and biophysical environment. Given the finite lifespan of osteoblasts, this continued bone formation requires replenishment from a progenitor population. Although this is largely believed to be from a skeletal stem cell population, given the limitation in in-vivo markers for this cell type, progress in demonstrating this mechanism is limited. Therefore, we characterized the LepR-Cre mouse strain and evaluated whether LepR positive cells are the progenitor population and if they contribute to the osteoblast population over time and in mechanically-induced bone formation in-vivo. Transgenic mouse strains; B6.129(Cg)-Leprtm2(cre)Rck/J to study LepR-expressing cells and B6.Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze/J as a reporter strain were obtained from Jackson Laboratories. Characterization studies were performed on LepR:tdTomato mice at embryonic stage (19.5dpc), 8 and 12 weeks old. Mice (12 weeks old) were subjected to compressive tibia loading with a 11N peak load for 40 cycles, every other day for 2 weeks. Histological analysis reveal that LepR is expressed from the embryonic stage in various organs including bones. LepR positive cells are found around blood vessels and on bone surfaces. Flow cytometry analysis show the amount of LepR positive cells negative for CD45 and Ter-119 markers inside the bone marrow increases over time and following tibial loading. Mechanical loading induces an increase in bone mass and bone parameters. This model allows us to track and evaluate the role of LepR positive cells as bone forming cells, and to decipher the role of these cells in mechanically-induced bone formation.

To evaluate the safety and efficacy of treating patients with Graf IIa developmental hip dysplasia.

The management of the developmentally immature Graf Type IIa dysplastic hip is controversial. Some authors advocate early treatment with an abduction harness whilst others adopt watchful waiting.

At our institution selective sonographic assessment for developmental dysplasia of the hip (DDH) was established in 1997 with prospective data collection. All infants diagnosed with Graf Type IIa hip(s) were treated with either a Pavlik harness or double nappies, with clinical and sonographic follow up until normalisation. Pelvic radiographs were routinely performed at 8 and 18 months follow up for assessment of residual dysplasia and/or complications of treatment. We evaluated the safety and efficacy of all treated patients between 2005 and 2013.

Complete clinical and radiological follow up (mean 2.1 years, 0.7–6.5) was available for 103 of 118 infants. 69 were treated with a Pavlik harness and 49 with double nappies. The chosen treatment was successful in 110 hips with no documented complications, well developed ossific nuclei on follow up radiographs, and no further treatments undertaken. In the double nappy group 4 infants deteriorated sonographically so were changed to a Pavlik harness with subsequent normalisation and successful treatment.

3 patients required VDRO at age 18 months (17–20) and 1 patient required closed reduction and spica cast treatment at age 11 months. No further complications arose in this group. The 15 patients lost to follow up had successful initial treatment but failed to attend for radiographic review.

Both Pavlik harness and double nappies are safe treatment modalities for Type IIa hip dysplasia. However, sonographic deterioration was observed in both groups with surgical intervention required in the minority, supporting the ongoing treatment of these immature hips.

Wear of polymeric glenoid components has been identified as a cause of loosening and failure of shoulder implants1,2 in vivo. A small number of shoulder joint simulators have been built for in vitro wear testing, however none have been capable of testing with physiological motion patterns in three axes and with physiological loading. The Newcastle Shoulder Wear Simulator was designed with three axes of motion, which are programmable so that different activities of daily living might be replicated. The simulator uses three pneumatic cylinders with integral position encoders to move five shoulder prostheses simultaneously in the flexion-extension, abduction-adduction, and internal-external rotation axes. Axial loading is applied with pneumatic cylinders supplied from a pneumatic proportional valve via a manifold, which also supplies a sixth static control station. In order to establish if that the machine can actually perform as intended, commissioning trials were conducted replicating lifting a 0.5 Kg weight to head height as a daily living activity. During the commissioning trials JRI Orthopaedics Reverse VAIOS shoulder prostheses were tested in 50% bovine serum at ambient temperature. The results show that the shoulder joint wear simulator can satisfactorily reproduce a daily living activity deliberately selected for having a large range of motion and loading. Other daily activities, such as drinking from a mug, are less demanding in the ranges of motion and loading and represent no difficulty in being reproduced on the simulator. Now successfully commissioned, this new multi-station shoulder wear simulator can wear test current and new designs of shoulder prosthesis in vitro

To report the clinical, functional and radiological outcome of consecutive primary hip arthroplasties using large diameter (36mm and above) ceramic bearing couples. We believe this to be one of the first independent series.

We prospectively reviewed 519 consecutive primary THA using fully HAC coated acetabular shell and fully HAC coated stem (JRI Ltd) in 502 patients, with minimum follow-up of 32 months. A Biolox-Delta ceramic liner with an 18 deg taper and Biolox-Delta ceramic head (36mm and 40mm) were used in all cases, by 3 surgeons. None were lost to follow-up. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Return to sports and hobbies were recorded.

Mean age was 64.9 yrs (11–82yrs). There were no dislocations. 50–62mm acetabular shells were used. 36 mm head was used in 92% of cases. No acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (1), peri-prosthetic fractures (1). The mean Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. The Charnley score was 5.7 (5–6) for pain, 5.8 (4–6) for movement and 5.9 (4–6) for mobility. There was a significant improvement in the range of movement of the hip. There was no migration of acetabular component. Acetabular radiolucencies were present around one shell. No acetabular liner wear was demonstrated in CT Scans. Mean inclination was 7.4deg(37–65). Mean EQ-5D description scores and health thermometer scores were 0.84 (0.71–0.92) and 88 (66–96). With an end point of definite or probable loosening, the probability of survival was 100%. Overall survival with removal or repeat revision of either component for any reason as the end point was 99.1%.

The results of this study show an excellent clinical and functional outcome and support the use of a fully coated prosthesis with ceramic bearing couples. We envisage monitoring and prospectively reporting the long-term outcome of this series of patients.

Introduction

Viscosupplementation is used widely to provide symptomatic relief to patients with knee OA. This study aimed to compare the efficacy and safety of the standard (3×2ml) and single (1×6ml) dosing regimens of hylan G-F 20

To discuss the rationale, selection criteria, indications, and results of using large diameter ceramic heads in revision hip arthroplasty.

We routinely use Biolox family of ceramic heads and acetabular liners in patients undergoing revision total hip replacements. We present our experience in using ceramic articular bearings over the last 20 years and the switch to larger diameter ceramic heads. We also present our rationale for using a large diameter ceramic head instead of a large metal head.

We reviewed a total of 689 revision arthroplasties over this time period and we report the outcome of large bearing couples with case examples in primary and revision scenarios. Furthermore we compared a subset of patients (110) with large diameter ceramic heads – Biolox Delta 36mm to patients who had metal on metal (large head 42 mm and above) bearing couples. The performance of the ceramic bearing couples will be discussed along with the functional outcome of these patients. We found no difference in the functional, clinical sports activities (UCLA and Tegner scores) between patients who had large metal bearing couples and large ceramic couples. Complication rate was less with the ceramic bearing revision arthroplasties, as was patient satisfaction.

Ceramic bearing couples have stood the test of time and have demonstrated an excellent long term wear properties. The recent introduction of the large diameter couples proves to be an excellent alternative if not the first choice in young, complex primary and revision case scenarios.

Introduction

Viscosupplementation is used widely to provide symptomatic relief to patients with knee OA. This study aimed to compare the efficacy and safety of the standard (3×2ml) and single (1×6ml) dosing regimens of hylan G-F 20.

Earlier diagnosis is one of the key aims in achieving improved outcomes for patients with cancer. In general, the earlier a tumour is diagnosed, the easier it will be to treat and the greater the chance of cure. We have investigated how tumour size at diagnosis and duration of symptoms, both of which may act as a proxy for delay in diagnosis have varied over a 25 year period and whether there is evidence of improvement.

Data were available for 2568 patients with primary bone sarcomas and 2366 with soft tissue sarcomas. The mean size at diagnosis was 10.7 cm for bone tumours and 9.9cm for soft tissue sarcomas. The size of bone sarcomas had not changed with the passage of time but there had been a slight decrease in the size of soft tissue sarcomas (10.3 cm before 2000 vs 9.6cm after 2000, p=0.03). The duration of symptoms reported by patients varied widely with a median of 16 weeks for bone sarcomas and 26 weeks for soft tissue sarcomas. The median duration of symptoms for bone sarcomas had actually increased since 2000 (16 weeks before to 20 weeks after 2000, p⋋0.01), whilst it remained unchanged for soft tissue sarcomas. Further analysis showed that females tended to present with smaller tumours than males and that slower growing tumours (eg. liposarcoma and chondrosarcoma) tended to be larger and have a longer duration of symptoms than other tumours. 15% of patients with a soft tissue sarcoma had undergone a previous inadvertent excision – and this % has not changed over 20 years. Younger patients had smaller soft tissue soft tissue sarcomas than older patients but there was little difference for bone sarcomas.

We aim to report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong HAC coated femoral and acetabular components.

We reviewed 586 consecutive cementless primary THA in 542 patients with a minimum 12-18 year follow-up, performed at one institution between 1986 and 1994. Twenty-eight (32 THA) were lost to follow-up. Clinical outcome was measured using Harris, Charnley and Oxford scores. Quality of life using EuroQol

EQ-5D. Radiographs were systematically analysed.

The mean age was 75.2 years. Dislocation occurred in 12 patients (three recurrent). Re operations were performed in 11 patients (1.9%). Four acetabular and one stem revisions were performed for aseptic loosening. Other re-operations were for infection (two), periprosthetic fractures (two), cup malposition (one), revision of worn liner (two). The mean Harris and Oxford scores were 89 (79–96) and 18.4 (12–32) respectively. The Charnley score was 5.7 for pain, 5.3 for movement and 5.4 for mobility. Acetabular radiolucencies were present in 54 hips (9.7%).

The mean linear polythene wear was 0.06 mm/year. Stable stem by bony ingrowth was identified in all hips excluding one femoral revision case. Mean stem subsidence was 2.2mm (0.30–3.4mm). Radiolucencies were present around 37 (6.6%) stems. EQ- 5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, survival at 12 years was 96.1% for acetabular and 98.3% for femoral components. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 97.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period.

We report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic (HAC) coated acetabular components.

We reviewed 412 consecutive cementless primary THA using fully coated acetabular shell in 392 patients—with a minimum 12 to 18 year follow-up—performed at two institutions between 1986 and 1994. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study. Fully HAC coated stems were used in all patients. The clinical outcome was measured using Harris, Charnley and Oxford hip scores and the quality of life using EuroQol EQ-5D. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured. The radiographic stability of the acetabular component was determined by Enghs criteria.

The mean age was 74.4 years. The mean Harris and Oxford scores were 87 (78– 97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5-6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in four hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4° (38–65).

Radiolucencies were present around 37 (6.6%) stems. Dislocation occurred in 10 patients (three recurrent). Re-operations were performed in nine patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (three), periprosthetic fractures (one), cup malposition (one) and revision of worn liner (three). Mean EQ-5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 97.1% for acetabular component. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 96.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period.

Bone and Soft Tissue Sarcomas represent approximately 1% of all malignant tumours. Delays in diagnosis are frequent and the average size of Sarcomas at diagnosis has averaged 10cm for many years. In 1999 guidance was produced by NICE with the aim of leading to the earlier diagnosis of common cancers – including Sarcomas. We have attempted to analyze whether this guidance has had any impact on either the size of the tumours at diagnosis or the symptom duration prior to diagnosis experienced by the patients.

Data for patients referred to the Royal Orthopaedic Hospital in Birmingham between 1992 and 2007 with Bone Sarcomas (n=1592) and Soft Tissue Sarcomas (n=2004) were analysed to determine the effect of the guidance. For Bone Sarcomas the mean size of the tumours decreased from 11.2cm prior to the guidance to 10.7cm after the guidance but the change was not statistically significant (p=0.09). The mean duration of symptoms increased from 18 to 21.2 weeks (p=0.01). For Soft Tissue Sarcomas, mean size fell from 10.8cm to 9.5cm (p<0.001), however the duration of symptoms actually increased from 27.3 to 32.1 weeks (p=0.01). Statistical modelling using restricted cubic splines confirmed these trends in the data.

These results show that whilst there may have been a slight improvement in the size at diagnosis of Soft Tissue Sarcomas, overall most patients still experience a long delay between the onset of symptoms and diagnosis and commencement of treatment. It is difficult to conclude that the early diagnosis guidance produced in 1999 has had a significant effect on the basis of this study. Strategies to improve awareness of the symptoms and clinical features of Bone and Soft Tissue Sarcomas are still urgently required.

Objectives

To assess the affects of a delay in diagnosis on the survival rates of Bone Sarcoma (BS) using size and symptom duration as measures of delay.

Objective

Sarcomas are a rare group of tumours, which pose numerous problems regarding correct diagnosis and appropriate management. This study aimed to examine whether symptom duration and tumour size at diagnosis have changed over time, using size and symptom duration as methods of comparison.

Current guidelines suggest that most lumps less than 5cm in size will not be malignant. We reviewed our experiences of small lumps at the Royal Orthopaedic Hospital, Birmingham, in order to try and identify factors associated with malignancy. All referrals to our clinic were included and data on size, symptoms, depth and diagnosis were analysed. We identified 325 patients, with 57 (17.5%) malignant and 268 (82.5%) benign lumps. Size >3cm was the most accurate predictor of malignancy (35.8% malignant vs 9.9% <3cm). 23.6% of lumps reported as increasing size were found to be malignant, compared to 8.6% of those that were not. Pain was found to be a poor predictor of malignancy, with only 15.5% of painful lumps found to be malignant and 18.9% of painless lumps found to be malignant. ‘Size >3cm’ has a sensitivity of 73.6% and a specificity of 56.3%, ‘Depth’ has a sensitivity of 73.6% and a specificity of 30.2%, ‘Increasing in Size’ a sensitivity of 71.4% and a specificity of 56.7% and ‘Pain’ a sensitivity of 33.3% and a specificity of 57.1%. If a lump has none of the above features then one can be 89.5% certain that it is not malignant. If it has 1 feature there is a 16.1% chance of its becoming malignant, 2 features a 58% chance, 3 features an 87% chance and if a lump has all 4 features there is a 93.5% chance of its being found to be malignant.

The main limitation with this study is that the data set is skewed because all lumps referred to the Oncology Department are by their nature suspicious. This study identifies those factors which suggest malignancy in small lumps and provides the basis for carrying out a large, community-based study on all lumps, to identify features associated with malignancy.

Aim

To compare the clinical effectiveness, functional outcome and patient satisfaction following intra articular injection with Synvisc^¯ and Hyalgan^¯ in patients with osteoarthritis (OA) of the knee.

Purpose: Reducing wait times for total hip (THA) or knee (TKA) joint arthroplasty is a Canadian health care priority. Models that maximise the capacity of advanced practice clinicians (nurses, physical therapists, sports medicine specialists) have been established to streamline care. Hospitals across the Hamilton Niagara Haldimand Brant Local Health Integration Network in Ontario collaborated to establish a Regional Joint Assessment Centre (RJAC). This study was designed to profile patients deemed suitable for surgical review, and to examine wait times for THA or TKA in RJAC patients compared to those referred directly to an orthopaedic surgeon’s office.

Method: Patients referred to the RJAC between July 2007 and August 2008 with knee or hip OA were included. Self-reported function was evaluated using the Oxford Hip and Knee Score that is scored out of 60 (higher scores reflect greater disability). Time to surgery was measured as the number of days from initial review to surgery. Group one consisted of patients that were referred to the RJAC while group two was comprised of patients who were referred directly to a surgeon’s office. Patient characteristics were examined using univariate analyses. Independent t-tests were used to examine between group differences.

Results: One hundred thirty-six patients (mean±sd: 68±2 years, body mass index 31±6 kg/m2, 83 females) with 150 hip and/or knee joint problems were reviewed in the RJAC. Of those, only 33% (45/136 patients) were deemed suitable for surgical review. Self-reported function (Oxford Scores) in the group requiring surgical review was significantly worse (40±7, p=0.03) than in those patients deemed unsuitable for surgical review (37±9). The RJAC group waited on average 130 days for THA and 129 days for TKA (below the provincial target of 182 days) while those referred directly to the surgeons’ offices waited significantly longer (194 days for THA and 206 days for TKA, p< 0.001).

Conclusion: Patients with hip and knee OA who require surgical review have worse self-reported function than those triaged to conservative care. Wait times for THA or TKA were significantly shorter for patients referred to the RJAC under the new model of care than for those referred directly to an orthopaedic surgeon’s office.

Aim: To discuss the rationale, selection criteria, indications, and results of using large diameter ceramic heads in primary and revision hip arthroplasty.

Patients and Methods: We routinely use Biolox family of ceramic heads and acetabular liners in patients undergoing total hip replacements. We present our experience in using ceramic articular bearings over the last 20 years and the switch to larger diameter ceramic heads. We also present our rationale for using a large diameter ceramic head instead of a large metal head.

Results: We reviewed a total of 1189 arthroplasties over this time period and we report the outcome of large bearing couples with case examples in primary and revision scenarios. Furthermore we compared a subset of patients (110) with large diameter ceramic heads – Biolox Delta 36mm to patients who had metal on metal (large head 42 mm and above) bearing couples. The performance of the ceramic bearing couples will be discussed along with the functional outcome of these patients. We found no difference in the functional, clinical sports activities (UCLA and Tegner scores) between patients who had large metal bearing couples and large ceramic couples. Complication rate was less with the ceramic bearing arthroplasties, as was patient satisfaction

Conclusion: Ceramic bearing couples have stood the test of time and have demonstrated an excellent long term wear properties. The recent introduction of the large diameter couples proves to be an excellent alternative if not the first choice in young, complex primary and revision case scenarios

Aim: To report the clinical, functional and radiological outcome of consecutive primary hip arthroplasties using large diameter (36mm and above) ceramic bearing couples. We believe this to be one of the first reported series in the UK.

Methods: We prospectively reviewed 319 consecutive primary THA using fully HAC coated acetabular shell and fully HAC coated stem (JRI Ltd) in 302 patients, with minimum follow-up of 12 months. A Biolox-Delta ceramic liner with an 18 deg taper and Biolox-Delta ceramic head (36mm and 40mm) were used in all cases, which were performed in one institution by 3 surgeons. None were lost to follow-up. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Return to sports and hobbies were recorded.

Results: Mean age was 64.9 yrs (11–82yrs). There were no dislocations. 50–62mm acetabular shells were used. 36 mm head was used in 96% of cases. No acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (1), peri-prosthetic fractures (1). The mean Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. The Charnley score was 5.7 (5–6) for pain, 5.8 (4–6) for movement and 5.9 (4–6) for mobility. There was a significant improvement in the range of movement of the hip. There was no migration of acetabular component. Acetabular radiolucencies were present around one shell. No acetabular liner wear was demonstrated in CT Scans. Mean inclination was 47.4deg(37–65). Mean EQ- 5D description scores and health thermometer scores were 0.84 (0.71–0.92) and 88 (66–96). With an end point of definite or probable loosening, the probability of survival was 100%. Overall survival with removal or repeat revision of either component for any reason as the end point was 99.1%.

Conclusion: The results of this study show an excellent clinical and functional outcome and support the use of a fully coated prosthesis with ceramic bearing couples. We envisage to monitor and prospectively report the long-term outcome of this series of patients.

We aim to report the clinical, radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic coated acetabular components. We reviewed 412 consecutive primary THA using fully coated acetabular shell in 392 patients, with minimum 12-year follow-up to 18 years, performed at two institutions. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study.

Fully HAC coated stems were used in all patients. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured.

Mean age was 74.4 yrs. Dislocation occurred in 10 patients (3 recurrent). Revision operations were performed in nine patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (3), periprosthetic fractures (1), cup malposition (1), revision of worn liner (3). The mean Harris and Oxford scores were 87 (78–97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5–6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in 4 hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4 deg(38–65). Mean EQ-5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 96.1%. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 94.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long term period

The aim of this study was to compare the clinical outcome, radiological outcome, activity level and functional outcome of hip resurfacing against metal on metal (MOM) hip arthroplasty.

Matched pairs of patients were selected from consecutive patients who had either MOM arthroplasty (n=236) or hip resurfacing (n=264). We matched 346 patients (173 pairs) in terms of age, sex, diagnosis, and a minimum follow up of 60 months. The functional outcome was assessed using Harris, Charnley-MDP, SF-36, UCLA and Tegner scores. Mean follow up was 67 months (61–80).

Mean age was 54.5 years. Femoral neck fractures were seen in 4 patients in the resurfacing group. The mean acetabular inclination was 42.8 deg and 44.3 deg in the resurfacing and MOM groups. Mean stem subsidence was 1.2mm. Bony ingrowth was seen in ninety six stems and all stems were stable by Engh s criterion. Radiolucent halo was observed around the stem of two resurfacing heads. The mean Harris hip score was 87.9 and 88.2 in the MOM and resurfacing groups respectively (p=0.76). The SF 36 score was 77.8 and 80.1 (p=0.4). The UCLA and Tegner scores were 6.1 and 3.6 for the resurfacing group and 5.9 and 3.9 for the MOM group. Nine patients in the resurfacing group had a postoperative painful limp which settled by 3 months. There was no radiological evidence of implant failure at last follow up. Survival at 5 years was 100% for the MOM group and 94.1% for the resurfacing group.

Functional outcome and activity levels increased in both groups with no difference between the groups. Post operative complications were fewer in MOM group and return to activity was quicker. It appears that resurfacing arthroplasty offers no medium term advantages over MOM arthroplasty. However longer follow up is required to establish the longevity and durability of this implant.