We present the clinical results and survivorship of consecutive 100 Birmingham Hip Resurfacings in 90 patients at a minimum follow-up of ten years. All procedures were carried out by an independent surgeon who commenced a prospective study in 1998. Patients were assessed clinically using the Western Ontario and McMaster Universities osteoarthritis index, Short-Form 36, Harris hip score and University of California, Los Angeles activity score. Radiological analysis was performed by an independent observer and blood metal ion levels concentrations were measured at ten years post-operatively in 62 patients. The median acetabular component inclination was 46.2° (34° to 59°) and anteversion 11.0° (0° to 30°). The median chromium concentration in the unilateral group was 1.74 (0.41 to 15.23) and for the bilateral group was 2.98 (1.57 to 18.01). The equivalent values for cobalt were 1.67 (0.54 to 20.4) and 1.88 (1.38 to 19.32).

In total there were eight failures giving an overall survival at ten years of 92% (95% confidence interval (CI) 86.7 to 97.3). BHR in male patients had an improved survivorship of 94.6% (95% CI 89.4 to 100) compared with females at 84.6% (95% CI 70.7 to 98.5), but this did not reach statistical significance (p = 0.119). Four of the nine BHRs with a bearing diameter of 42 mm failed.

The overall results were consistent with data produced from other centres in that the clinical outcome of large male patients was extremely encouraging, whereas the survival of the smaller joints was less satisfactory.

Reports of improved functional outcome of Metal on Metal Hip Resurfacing Arthroplasty (mHRA) to Total Hip Replacement needs to be balanced with concerns of metal ion release. By removing cobalt-chrome, cHRA reduces these risks. To the author's knowledge, there is no data available on functional outcomes of cHRA, therefore the aim of the study was to compare the function between cHRA patients and mHRA patients. 24 patients received a unilateral cHRA (H1, Embody) and was compared to 24 age and gender matched patients with a unilateral mHRA (BHR, Smith and Nephew). All patients completed the Oxford Hip Score (OHS)[T2] and underwent gait analysis on an instrumented treadmill before and at a mean of 74wks (+/− 10) for mHRA and 53wks (+/− 2) for cHRA post op. Walking trials started at 4km/h and increased in 0.5km/h increments until a top walking speed (TWS) was achieved. Vertical ground reaction forces (GRF) were recorded along with the symmetry index (SI). Spatiotemporal measures of gait were also recorded. Vertical GRF were captured for the entire normalised stance phase using statistical parametric mapping (SPM; CI = 95%). The gain in OHS was similar: H1 (25-46), BHR(27-47). TWS increased by 19% with H1 (6.02 – 8.0km/hr), and 20% with BHR (6.02 – 7.37km/hr). SPM of the entire gait cycle illustrated the restoration of symmetry in both groups with no difference in GRF across the stance phase between groups at 5km/hr pre-op and post-op. At faster speeds (6.5km/hr), H1 patients had a mid-support GRF slightly closer to normal compared to BHR. Both groups increased step length similar from pre to post op (H1:0.76 – 0.85cm, BHR:0.77-0.86cm). In this study, subjective and objective functional outcome measures suggest that short term functional outcomes of ceramic resurfacing is not inferior to metal resurfacing

Aims. The Birmingham Hip Resurfacing (BHR) arthroplasty has been used as a surgical treatment of coxarthrosis since 1997. We present 20-year results of 234 consecutive BHRs performed in our unit. Methods. Between 1999 and 2001, there were 217 patients: 142 males (65.4%), mean age 52 years (18 to 68) who had 234 implants (17 bilateral). They had patient-reported outcome measures collected, imaging (radiograph and ultrasound), and serum metal ion assessment. Survivorship analysis was performed using Kaplan-Meier estimates. Revision for any cause was considered as an endpoint for the analysis. Results. Mean follow-up was 20.9 years (19.3 to 22.4). Registry data revealed that 19 hips (8.1%) had been revised and 26 patients (12%) had died from causes unrelated to the BHR. Among the remaining 189 hips, 61% were available for clinical follow-up at 20 years (n = 115) and 70% of patients had biochemical follow-up (n = 132). The cumulative implant survival rate at 20 years for male patients was 96.5% (95% confidence interval (CI) 93.5 to 99.6), and for female patients 87% (95% CI 79.7 to 94.9). The difference was statistically significant (p = 0.029). The mean Oxford Hip Score, Hip disability and Osteoarthritis Outcome Score, and Forgotten Joint Score were 45 (29 to 48), 89 (43 to 100), and 84 (19 to 100), respectively. The mean scores for each of the five domains of the EuroQol five-dimension three-level questionnaire were 1.2, 1.0, 1.2, 1.3, and 1.1, and mean overall score 82.6 (50 to 100). Ultrasound showed no pseudotumour. Mean cobalt and chromium levels were 32.1 nmol/l (1 to 374) and 45.5 nmol/l (9 to 408), respectively. Conclusion. This study shows that BHRs provide excellent survivorship and functional outcomes in young male patients. At 20 years, soft-tissue imaging and serum metal ion studies suggest that a metal-on-metal resurfacing implant can be well tolerated in a group of young patients. Cite this article: Bone Joint J 2023;105-B(9):946–952

Aims. The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. Methods. The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken. Results. Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83). Conclusion. This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs. Cite this article: Bone Joint J 2024;106-B(6):540–547

Aims. The first aim of this study was to evaluate whether preoperative renal function is associated with postoperative changes in whole blood levels of metal ions in patients who have undergone a Birmingham Hip Resurfacing (BHR) arthroplasty with a metal-on-metal bearing. The second aim was to evaluate whether exposure to increased cobalt (Co) and chromium (Cr) levels for ten years adversely affected renal function. Methods. As part of a multicentre, prospective post-approval study, whole blood samples were sent to a single specialized laboratory to determine Co and Cr levels, and the estimated glomerular filtration rate (eGFR). The study included patients with 117 unrevised unilateral BHRs. There were 36 females (31%). The mean age of the patients at the time of surgery of 51.3 years (SD 6.5), and they all had preoperative one-, four-, five-, and ten-year laboratory data. The mean follow-up was 10.1 years (SD 0.2). Results. Median Co levels at one year postoperatively increased significantly compared with the preoperative values, by a factor of 9.7, from 0.13 to 1.26 ppb (p < 0.001), and the median Cr levels increased significantly by a factor of 2.5, from 0.60 to 1.50 ppb (p < 0.001). Lower preoperative eGFRs were associated with significantly larger increases in Co at one year compared with the preoperative levels (ρ = -0.26; p = 0.005), but there was no relationship between preoperative eGFRs and changes in Cr at one year (ρ = -0.13; p = 0.153). Metal levels remained relatively constant with the passage of time, with a median ten-year value of 1.12 ppb for Co and 1.29 ppb for Cr. There was no significant relationship between the Co and Cr levels at ten-year follow-up and the change in eGFR from the preoperative level to that at ten years (ρ = -0.02; p = 0.827 for Co; ρ = -0.008; p = 0.933 for Cr). Conclusion. Although patients with lower preoperative eGFRs tended to have larger increases in Co levels at one year, increased metal levels for patients who underwent unilateral BHR did not adversely affect renal function during the first ten postoperative years. Cite this article: Bone Joint J 2024;106-B(3 Supple A):44–50

Aims. It is not known whether change in patient-reported outcome measures (PROMs) over time can be predicted by factors present at surgery, or early follow-up. The aim of this study was to identify factors associated with changes in PROM status between two-year evaluation and medium-term follow-up. Patients and Methods. Patients undergoing Birmingham Hip Resurfacing completed the Veteran’s Rand 36 (VR-36), modified Harris Hip Score (mHHS), Tegner Activity Score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at two years and a minimum of three years. A change in score was assessed against minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) thresholds. Binary logistic regression was used to assess the relationship between patient factors and deterioration in PASS status between follow-ups. Results. Overall, 18% of patients reported reductions in mHHS total score exceeding MCID, and 21% reported similar reductions for WOMAC function scores. Nonetheless, almost all patients remained above PASS thresholds for WOMAC function (98%) and mHHS (93%). Overall, 66% of patients with mHHS scores < PASS at two years reported scores > PASS at latest follow-up. Conversely, 6% of patients deteriorated from > PASS to < PASS between follow-ups. Multivariable modelling indicated body mass index (BMI) > 27 kg/m. 2. , VR-36 Physical Component Score (PCS) < 51, VR-36 Mental Component Score (MCS) > 55, mHHS < 84 at two years, female sex, and bone graft use predicted these deteriorating patients with 79% accuracy and an area under the curve (AUC) of 0.84. Conclusion. Due to largely acceptable results at a later follow-up, extensive monitoring of multiple PROMs is not recommended for Birmingham Hip Resurfacing patients unless they report borderline or unacceptable hip function at two years, are female, are overweight, or received a bone graft during surgery. Cite this article: Bone Joint J 2019;101-B:1431–1437

Abstract. Background. To determine the long-term survival outcomes of Copeland Resurfacing Hemiarthroplasty (CRHA) performed by a single surgeon series. Methods. A retrospective cohort study which looked at patients who underwent CRHA over 6 years. Re-operations including revisions with component exchange taking place in our hospital and at local centres were reviewed. Oxford Shoulder Score (OSS) was used to assess their functional outcomes pre- and post-CRHA. Results. 80 CRHAs were performed in 72 patients between 2007 and 2013 with a mean follow-up of 6.5 years. The mean follow-up was 79 months (50–122). The primary indication for CRHA was osteoarthritis (76.3%), cuff tear arthropathy (16.3%), rheumatoid arthritis (5%) and post-trauma (1.3%). The mean pre-operative OSS was 16, which doubled following CRHA surgery. Fifteen patients underwent revision surgery due to ongoing glenoid pain with a mean revision time following primary CRHA being 49 months. Projected survival at the endpoints 5,7 and 10 years were 83, 81 and 79% respectively. Conclusion. This study provides us with a much longer average follow-up period in comparison to many other studies published. Previous studies, support resurfacing as a useful implant in reducing pain and improving function in the short-term; but this series demonstrates over the medium-term a relatively high revision rate of about 20% in comparison with other arthroplasty options, despite the revision rate seeming to plateau from the 5-year mark onwards

Aims. During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the National Institute for Health and Care Excellence (NICE) recommended always resurfacing the patella, rather than never doing so. NICE found insufficient evidence on selective resurfacing (surgeon’s decision based on intraoperative findings and symptoms) to make recommendations. If effective, selective resurfacing could result in optimal individualized patient care. This protocol describes a randomized controlled trial to evaluate the clinical and cost-effectiveness of primary TKR with always patellar resurfacing compared to selective patellar resurfacing. Methods. The PAtellar Resurfacing Trial (PART) is a patient- and assessor-blinded multicentre, pragmatic parallel two-arm randomized superiority trial of adults undergoing elective primary TKR for primary osteoarthritis at NHS hospitals in England, with an embedded internal pilot phase (ISRCTN 33276681). Participants will be randomly allocated intraoperatively on a 1:1 basis (stratified by centre and implant type (cruciate-retaining vs cruciate-sacrificing)) to always resurface or selectively resurface the patella, once the surgeon has confirmed sufficient patellar thickness for resurfacing and that constrained implants are not required. The primary analysis will compare the Oxford Knee Score (OKS) one year after surgery. Secondary outcomes include patient-reported outcome measures at three months, six months, and one year (Knee injury and Osteoarthritis Outcome Score, OKS, EuroQol five-dimension five-level questionnaire, patient satisfaction, postoperative complications, need for further surgery, resource use, and costs). Cost-effectiveness will be measured for the lifetime of the patient. Overall, 530 patients will be recruited to obtain 90% power to detect a four-point difference in OKS between the groups one year after surgery, assuming up to 40% resurfacing in the selective group. Conclusion. The trial findings will provide evidence about the clinical and cost-effectiveness of always patellar resurfacing compared to selective patellar resurfacing. This will inform future NICE guidelines on primary TKR and the role of selective patellar resurfacing. Cite this article: Bone Jt Open 2024;5(6):464–478

We report a rare case of Hip Resurfacing dislocation three years after a bilateral Hip Resurfacing in a very strong patient and show the maneuver to do a closed reduction on a film done at the surgical theatre under general anesthesia. Hip resurfacing dislocation is a very rare entity described in the literature and more rare after three years. With conventional total hip replacement the dislocation rate is 2–5%. In the international literature the dislocation rate with resurfacing is 0.21%. We describe a case of a 47 years old male patient who was submitted to a biltateral 54 × 60 mm Hip Resurfacing in November 16 th and 18th, 2011 (two separate days). He had a normal post op and returned to his work after six weeks and recreational activities after four months. Three years later, on November 8th, 2014 he did an extreme movement of hip flexion, adduction and internal rotation when he was gardening and planting a tree seedling suffering a left hip dislocation. Hopefully we could reduce the dislocated hip in a closed manner in the following morning. Patient went home next day but on that same night had important abominal pain needing to return to hospital when numerous gallbladder stones where found being submitted to a total laparoscopic colecistectomy two days later. It was really a bad luck week. Metal ions are still normal and patient is symptomless until today having returned to his recreational activities. We will show in a movie the maneuver to do this closed reduction and hope by showing this maneuver that our colleagues do not have to do an open dislocation in the future in case they face a Hip Resurfacing dislocation

When the Birmingham Hip Resurfacing (BHR) metal-on-metal implant system was approved by the United States Food and Drug Administration in 2006, a multicenter, prospective, post-approval study (PAS) was required. This study uses data from the PAS to investigate metal level and glomerular filtration rate (GFR) trends over the first decade in vivo. Between October 2006 and March 2011, 290 primary BHR procedures were performed among 262 patients at 5 sites. Whole blood samples were sent to a single specialized laboratory to determine GFR, cobalt (Co) and chromium (Cr) levels. The population for this study consists of 117 unrevised unilateral patients with a mean age at surgery of 51.3±6.5 years who had pre-operative, 1-year, 4-year, 5-year and 10-year laboratory data. The mean follow-up for these patients that included 36 females was 10.1±0.2 years. Median metal levels at 1-year increased relative to pre-operative values for Co (by a factor of 9.7 from 0.13 to 1.26 ppb, p<0.001) and Cr (by a factor of 2.5 from 0. 60 to 1.50 ppb, p<0.001). Metal levels subsequently remained relatively constant over time with a median 10-year value of 1.12 ppb for Co and 1.29 ppb for Cr. Based on 585 blood samples from all 117 patients, there was no relationship between GFR and Co (. →. =−0.06, p=0.14) or Cr (. →. =0.05, p=0.27) levels. However, lower pre-operative GFR values were associated with larger increases in Co at 1-year relative to the pre-operative level (. →. =−0.26, p=0.005). There was no relationship between pre-operative GFR values and changes in Cr at 1 year (. →. =−0.13, p=0.15). Through the first decade in vivo, elevated whole blood metal levels for unilateral BHR patients do not appear to adversely affect GFR. However, patients with lower pre-operative GFR values tend to have larger increases in their Co level at 1-year

Aims

Elevated blood cobalt levels secondary to metal-on-metal (MoM) hip arthroplasties are a suggested risk factor for developing cardiovascular complications including cardiomyopathy. Clinical studies assessing patients with MoM hips using left ventricular ejection fraction (LVEF) have found conflicting evidence of cobalt-induced cardiomyopathy. Global longitudinal strain (GLS) is an echocardiography measurement known to be more sensitive than LVEF when diagnosing early cardiomyopathies. The extent of cardiovascular injury, as measured by GLS, in patients with elevated blood cobalt levels has not previously been examined.

Abstract. Objectives. Patella resurfacing in primary total knee arthroplasty (TKA) remains a contentious issue. Australian rates of patellar resurfacing are 66.6%, significantly higher compared to UK rates of 8–15% and Swedish rates of 2%. Resurfacing has gained popularity in Australia since registry data has shown decreased revision rates with no increase in patellar component related complications. We present for discussion an analysis of 113,694 total knee arthroplasties using commonly implanted prostheses in the UK. Methods. We included all TKA's since the Australian register's conception on 01/09/1999 for a primary diagnosis of osteoarthritis involving the use of either the Triathlon or Duracon implant with and without patellar components. The primary outcome of the study was time to revision for Triathlon's resurfaced and non-resurfaced prosthesis compared to the Duracon's equivalent data. We also analysed the reasons for revision between the 4 groups, type of revision and complication rates. We then compared minimally stabilised and posterior stabilised prostheses. Results. The cumulative revision rate for Triathlon prostheses with resurfacing after 12 years was 3.2% (95% CI, 2.9% to 3.6%) compared to 5.6% (95% CI, 5.0% to 6.2%) without resurfacing. Duracon's equivalent data was 6.3% with resurfacing and 5.9% without resurfacing. Triathlon prosthesis with resurfacing have much lower rates of revision due to loosening, patellofemoral pain, patellar erosion compared to unresurfaced Triathlon prostheses. Conclusion. Triathlon with re-surfacing has lower revision rates regardless of age or BMI. Previous concerns regarding patellofemoral loosening, tibial wear, maltracking relate to Duracon only, indicating the importance of implant specific studies. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. Hip resurfacing arthoplasty (HRA) is an alternative to total hip arthroplasty (THA), which has increased in the last years, especially in young patients. A suitable positioning of the resurfacing head is important, mainly because it is strongly related with the neck fracture. The goal of this work was to evaluate the influence of the resurfacing head positioning in the load distribution along the femurs’ structures. Materials and methods. Using 3D scan technology, the exterior geometry of a composite femur, used to create the FE models, was obtained. Three resurfacing models were used in three different positions in the frontal plane. A model with a positive offset of +5mm (Resurfacing #1), in neutral position (Resurfacing #2), and with a negative offset of −5mm (Resurfacing #3) was developed. A Birmingham® Hip Resurfacing prosthesis was chosen according to the femurs’ head. It was positioned in the femur and acetabulum by an experimented surgeon. The metal on metal contact pair was implemented. Models were aligned with 7° and 9°, considering the position of the anatomical femurs in sagittal and frontal planes. Models were constrained on the wing of the ilium and ischial tuberosity, allowing only vertical and rotational movements on the iliac side. Femurs were constrained on its distal side, allowing only rotational movements. Results. The most important strains in four different aspects, anterior, posterior, medial and anterior were analyzed. The highest differences occurred on the medial alignment of femurs. Comparing models Resurfacing #1 and Resurfacing #2, the highest displacement increase (11%) comparatively at the neutral position was observed. Besides, comparing models Resurfacing #2 and Resurfacing #3, displacement decrease of 13% (resurfacing #3) in the same region was observed. Thus, one can conclude that: a positive offset increases the strains on the femurs neck; a negative offset decreases the strains on the same region. According to these results, one can state that the risk of neck fracture in resurfacing implants slightly increases as the resurfacing head is positioned with a positive offset. Beyond that region, differences are not relevant

Introduction. Hip Resurfacing has been shown to be a valuable treatment for younger osteoarthritis patients related to functional outcomes. On the other hand, there is a higher risk for potential neck fractures and there is serious concern over metal-ion release and related health risks associated with the current metal-on-metal designs. Neck-preserving, short-stem implants may be a good alternative for younger patients. The current study investigated patient-reported outcomes from resurfacing and total hip arthroplasty (THA) with a neck preserving, short-stem implant (Corin MiniHip®). Methods. Hip disability and osteoarthritis outcome scores (HOOS) from a young group of patients (n= 52, age 48.9±6.1 years) who underwent hip resurfacing surgery and a cohort of patients who underwent MiniHip® THA surgery (n=73, age 48.2±6.6) were compared. MANCOVA analysis was conducted including follow-up period as covariate. To compare complexity of the surgical intervention, the average durations for both types of surgery were compared using non-parametric testing (Mann-Whitney's U). Results. As expected, both surgical interventions were associated with significant improvements in HOOS scores (p<0.0001, h2=.69); however, there were no group effects or interactions related to any of the HOOS subscales. Surgery duration was significantly longer for Resurfacing (104.4min±17.8) than for MiniHip® surgery (62.5min±14.8), U=85.0, p<0.0001, h2=.56. Conclusions. The current results indicate that the neck-preserving, short-stem approach via MiniHip Arthroplasty is equal to Resurfacing in terms of younger patients’ outcomes, while requiring shorter surgery duration. Additionally, there are serious concerns regarding the metal-on-metal designs of Resurfacing implants, which provides more support for the value of the presented short-stem alternative. Future research will aim at a longer-term (>5 years) evaluation of outcomes

A concern of metal on metal hip resurfacing arthroplasty is long term exposure to Cobalt (Co) and Chromium (CR) wear debris from the bearing. This study compares whole blood metal ion levels from patients drawn at one-year following Birmingham Hip Resurfacing (BHR) to levels taken at a minimum 10-year follow-up. A retrospective chart review was conducted to identify all patients who underwent a BHR for osteoarthritis with a minimum 10-year follow-up. Whole blood metal ion levels were drawn at final follow-up in June 2019. These results were compared to values from patients with one-year metal ion levels. Of the 211 patients who received a BHR, 71 patients (54 males and 17 females) had long term metal ion levels assessed (mean follow-up 12.7 +/− 1.4 years). The mean Co and Cr levels for patients with unilateral BHRs (43 males and 13 females) were 3.12 ± 6.31 ug/L and 2.62 ± 2.69 ug/L, respectively, and 2.78 ± 1.02 ug/L and 1.83 ± 0.65 ug/L for patients with bilateral BHRs (11 males and 4 females). Thirty-five patients (27 male and 8 female) had metal-ion levels tested at one-year postoperatively. The mean changes in Co and Cr levels were 2.29 ug/l (p = 0.0919) and 0.57 (p = 0.1612), respectively, at one year compared to long-term. These changes were not statistically significant. This study reveals that whole blood metal ion levels do not change significantly when comparing one-year and ten-year Co and Cr levels. These ion levels appear to reach a steady state at one year. Our results also suggest that regular metal-ion testing as per current Medicines and Healthcare products Regulatory Agency (MHRA) guidelines may be impractical for asymptomatic patients. Metal-ion levels, in and of themselves, may in fact possess little utility in determining the risk of failure and should be paired with radiographic and clinical findings to determine the need for revision

We present a consecutive case cohort of the first 100 Birmingham Hip Resurfacing (BHR)'s in 90 patients with a minimum follow up of 20 years. All procedures were performed by a single surgeon having commenced the study in 1998. The original cohort included 68 males with 75 hips (7 bilateral) and 22 females with 25 hips (3 bilateral). The mean age at index procedure was 52. Patients were recalled to review in clinic as per Medicines and Healthcare products Regulatory Agency guidelines with x-rays, metal ions and Harris Hip Scores recorded. After a minimum of 20 year follow-up review the known overall revision rate is 11%. 11 have died and 7 have been lost to review. In males the known revision rate is 4/75 (5%), 3 of which were due to early fractures and 1 revision for infection at 5 years. The known revision rate in females is 7/25 (28%) of which 6 were due to adverse reactions to metal debris; 3 at 7–8 yrs, 1 at 15 yrs, 2 at 18 years, and 1 at 2 months for avascular necrosis. The mean 20 year metal ions results were cobalt 36.6 nmol/l (range 7.4–232.1) and chromium 32.1 nmol/l (range 6–120.8). The mean Harris hip score was 88.5 (range 38.6–99.8). This case series with 20 years follow-up demonstrates excellent long term survival of the BHRs further to registry BHR data and similar to THR for same age recipients. Applying today's strict criteria for patient selection would likely improve survival rate further. BHR has not demonstrated the catastrophic revision rates associated with some metal-on-metal resurfacing and remains a safe option for those who meet the criteria

The 22 year survivorship of metal on metal hip resurfacing arthroplasty (RSA) is reported to be 94.3% with expert surgeons, in males with head sizes greater than 48mm. The 2023 National Joint Registry (NJR) report estimates survivorship of all RSA at 19 years to be 85%. This estimate includes all designs, head sizes and females. Our aim was to estimate the survivorship of RSA currently available for implantation (males only, head size >48mm, MatOrtho Adept or Smith and Nephew Birmingham Hip Resurfacing (BHR)) in those under 55 years, performed by all surgeons, compared to conventional THR. We performed a retrospective analysis of the NJR. We included all males under 55 years who had undergone BHR or Adept RSA with head size greater than 48mm. Propensity score matching was used to produce two comparable groups of patients for RSA or conventional THR. We matched in a 3:1 ratio (THR:RSA) using sex, ASA, BMI group, age at primary procedure, surgeon volume, diagnosis and surgeon grade as covariates. The primary analysis was survivorship at 18 years. Time-to-revision was assessed using Kaplan-Meier curves. Cox's proportional hazard models were used to investigate between group differences. 4839 RSA were available for analysis. After matching the RSA and THR groups were well balanced in terms of covariates. Survivorship at 18 years was 93.7% (95% CI 89.9,96.2) in the RSA group and 93.9% (90.5,96.0) in the THR group. Despite these similar estimates the adjusted hazard ratio was 1.40 (95% CI 1.18, 1.67 p<0.001) in favour of THR. Survivorship of the currently available RSA in males under 55 was 93.7% at 18 years, however THR survivorship was superior to RSA. These results, generalisable to UK practice, should be set against perceived benefits in functional status offered in RSA when counselling patients

It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups. These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side

We retrospectively reviewed the mid term outcome of 88 MoM THA in 84 patients and 21Hip Resurfacing using Recap Magnum bearing surface performed during 2006 – 2009. There were 41 males and 47 females in the THA group and 17 males and 4 females in the Hip Resurfacing group. All procedures were performed through a posterior approach. The average head size for the THR group was 46mm and the cup size was 52mm and the average head size for the resurfacing was 50mm and cup size was 56mm respectively. Median age for the THA group was 60 yrs. (28–73) and for the Resurfacing it was 51.5 yrs. (32–62). Average follow up was 76 months for the THA group and 78 months for the Resurfacing group. Average serum cobalt for the THA and the Resurfacing groups were 53.2nmol/l (119) and 30.85 and the Chromium levels were 82.44nmol/l(134.5) and 67.49 respectively. Eight MRI scans showed abnormal fluid collections suspicious of ARMD in the THA group and 2 showed fluid collection in the Resurfacing group. There were five revisions in the THA group with the tissue diagnosis of ALVAL. In all except one case a well fixed uncemented stem (Taperloc) was retained. In our series Recap Magnum on a Taperloc stem showed 94% survival at five years and therefore we continue to review the cases annually with serum cobalt chromium levels and MRI scans