Hip Resurfacing Research Articles

Clinical and Radiographic Outcomes With Minimum 2-Year Follow-up and Sub-Analysis of Navigation vs Non-Navigation for Hip Resurfacing.

The purpose of this study was to report the short-term clinical outcomes of hip resurfacing with navigation and the impact on accuracy of acetabular implant placement in both the frontal and sagittal planes. Data were retrospectively analyzed for patients who received hip resurfacing between 2010 and 2021. Eligible patients had postoperative radiographs and completed a minimum 2-year follow-up questionnaire for the following patient-reported outcomes: modified Harris Hip Score (mHHS), Harris Hip Score (HHS), Forgotten Joint Score (FJS), visual analog scale (VAS) score, satisfaction, and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS-JR). Hips were propensity matched in a 1:1 ratio based on the use of navigation, age, and body mass index. The percentage of hips that met the minimal clinically important difference (MCID) for mHHS and VAS score was noted. Component placement analysis was conducted based on the safe zones defined by Lewinnek and Callanan and the Relative Acetabular Inclination Limit. Seventy-six hips were matched, 38 per group. No differences were observed in patient-reported outcomes or the percentage of hips reaching MCID between the groups. The navigation group was 28.8 and 6.8 times more likely to be within the Callanan and Lewinnek safe zones, respectively. Based on the Relative Acetabular Inclination Limit, the navigation group was 3.1 and 6.4 times more likely to be within the 95% and 99% CI safe zones, respectively. Comparable improvements in patient-reported outcomes were observed in the two groups during a minimum 2-year follow-up. Navigation-assisted surgery enhances the accuracy of acetabular component positioning, with a higher likelihood of cup placement within the safe zones. [Orthopedics. 202x;4x(x):xx-xx.].

Hip & Pelvis

The October 2024 Hip & Pelvis Roundup360 looks at: Does the primary surgical approach matter when choosing the approach for revision total hip arthroplasty?; Time to achieve the minimal clinically important difference in primary total hip arthroplasty: comparison of anterior and posterior surgical approaches; To scope or not to scope: arthroscopy as an adjunct to PAO does not provide better clinical outcomes at one year than PAO alone; Re-exploring horizons in hip resurfacing: two-year results of a ceramic-on-ceramic hip resurfacing; Association between tranexamic acid and decreased periprosthetic joint infection risk in patients undergoing total hip and knee arthroplasty; Octogenarians fare well: in revision for infection age is not a bar.

Metal ion levels after metal-on-metal hip resurfacing: A single-center longitudinal study of Chinese patients.

This study aimed to investigate the long-term serum metal ion levels of patients who received metal-on-metal hip resurfacing arthroplasty (MoM HRA). We conducted a retrospective study of 99 patients (110 hips) from March 2006 to May 2017 who underwent MoM HRA. The Harris Hip Score (HHS) and the University of California at Los Angeles (UCLA) activity score were measured, and the patients underwent clinical and radiological management. Serum levels of cobalt (Co), chromium (Cr), and molybdenum (Mo) were measured using inductively coupled plasma mass spectrometry (ICPMS) at 1, 6, and 12 months, and each year follow-up after prosthesis implantation. Patients were followed up from 1 to 156 months, with a mean of 98 months. No complications occurred. Metal ion analysis revealed significantly elevated levels compared to preoperative levels. The metal ions levels increased and reached a peak after surgery, and then the levels began to decline gradually. Approximately 84-108 months after surgery, the metal ion levels increased again to approximately peak levels. Then, up to 156 months after surgery, the metal ions levels will drop approximately to preoperative levels. The serum levels of Cr in women were higher than those in men, with the difference being statistically significant. Patients with a body mass index (BMI) of ≥24.9 kg/m2 Co levels were significantly higher than those of normal-weight patients. The serum levels of metal ions showed no significant differences between the prostheses. The use of the MoM HRA was clinically effective, and the Co, Cr, and Mo levels increased significantly after HRA; however, upon long-term follow-up, serum metal ion levels tended to decrease to preoperative levels. Longer follow-up periods and larger study samples are needed to establish the long-term outcome of patients undergoing HRA with MoM bearings. Level IV, Therapeutic Study.

LONG-TERM RESULTS OF THE BIRMINGHAM HIP RESURFACING IMPLANT IN THE UNITED STATES: AN UPDATED ANALYSIS OF A SINGLE INSTITUTION'S EXPERIENCE

We previously reported the five to ten-year results of the Birmingham Hip Resurfacing (BHR) implant. The purpose of this study was to evaluate the survivorship, radiographic results, and clinical outcomes of the BHR at long-term follow-up.We retrospectively reviewed 250 patients from the original cohort of 324 BHRs performed from 2006 to 2013 who met contemporary BHR indications. Of these, 4 patients died and 4 withdrew. From the 242 patients, 224 patients (93%) were available for analysis. Modified Harris hip score (mHHS) and University of California, Los Angeles (UCLA) scores were collected and compared to a matched total hip arthroplasty (THA) cohort. Mean follow-up was 14 years.Survivorship free of aseptic revision was 97.4% and survivorship free of any revision was 96.0% at 15 years. Revisions included 3 periprosthetic joint infections, 2 for elevated metal ions and symptomatic pseudotumor, 2 for aseptic femoral loosening, and 1 for unexplained pain. The mean mHHS was 93 in BHR patients at final follow-up, similar to the THA cohort (p=0.44). The UCLA score was significantly higher for BHR patients (p=0.02), however there were equal proportions of patients who remained highly active (UCLA 9 or 10) in both groups, 60.5% and 52.2% (p=0.45) for BHR and THA respectively. Metal ion levels at long term follow-up were low (mean serum cobalt 1.8±1.5 ppb and mean serum chromium 2.2±2.0 ppb).BHR demonstrated excellent survivorship in males less than 60 years of age at time of surgery. Clinical outcomes and activity levels were similar to THA patients. Failures related to the metal-on-metal bearing were rare and metal levels were low at long-term follow-up.Level of evidence: IIIKeywords: survivorship; hip arthroplasty; activity; metal-on-metalSurface Replacement Arthroplasty demonstrates low revision rates and similar activity level compared to total hip arthroplasty at long-term follow-up.

LONG-TERM SURVIVORSHIP OF METAL-ON-METAL HIP RESURFACING ARTHROPLASTY: COMPARATIVE COHORT STUDY AT 15 YEARS

In 1997 the Birmingham Hip Resurfacing was introduced to address the needs of young active patients. Alternative designs were introduced to try and improve wear performance. The aim of this study was a comparative cohort study of two types of metal-on-metal bearing to determine the mechanism of failure at 15 years.The study reviewed 91 Brimingham Hip Resurfacings (BHR) (Smith and Nephew) and 715 DUROM hip resurfacing (Zimmer) procedures in prior to 2009. Failure was defined as revision of either component for any reason. Kaplan-Meyer survivorship analysis performed. Routine follow-up with serum metal ion levels and radiographs.Mean follow-up was 17.9 years (range 15.2 – 25.1). The mean age at operation was 51.6 years (SD 8.6, range 20.7 to 70.2), including 299 women (37.1%). The Birmingham resurfacing demonstrated 92.3% survivorship at 15 years (SE 2.8, 95% CI 3.9 – 7.8) and 90.0% at latest follow-up (SE 3.5, 95% CI 4.9 to 9.4). By comparison, the DUROM survivorship at 15 years was 89.1% at 15 years (SE 1.2, 95% CI 2.0 to 2.5) and 87.4% (SE 1.3, 95% CI 2.5 to 2.3) at latest follow-up. There was no statistically significant difference in survivorship between groups (p= 0.32). Survival in male patients was 92.7% compared to 80.0% in females. The reported failures occurred from Adverse Reaction to Metal Debris (32 patients), periprosthetic femoral neck fracture (6) and aseptic loosening (41), PJI (12) and undiagnosed pain (6). The mean cobalt and chromium levels at last follow-up were 33.4 nmol/L and 36.5 nmol/L respectively.This study demonstrates two differently designed metal-on-metal hip resurfacing provided a durable alternative to total hip replacement, particularly in younger male patients with osteoarthritis. Differences in design did determine the reason for revision with acetabular fixation being one of the principal failure mechanisms for the DUROM compared to elevated ion levels.

GAIT CHANGES FOLLOWING CERAMIC-ON-CERAMIC HIP RESURFACING ARTHROPLASTY: A PROSPECTIVE STUDY

A ceramic-on-ceramic hip resurfacing implant (cHRA) was developed and introduced in an MHRA-approved clinical investigation to provide a non metallic alternative hip resurfacing product. This study aimed to examine function and physical activity levels of patients with a cHRA implant using subjective and objective measures both before and 12 months following surgery in comparison with age and gender matched healthy controls.Eighty-two unilateral cHRA patients consented to this study as part of a larger prospective, non-randomised, clinical investigation. In addition to their patient reported outcome measures (PROMs), self- reported measures of physical activity levels and gait analysis were undertaken both pre- operatively (1.5 weeks) and post operatively (52 weeks). This data was then compared to data from a group of 43 age gender and BMI matched group of healthy controls. Kinetics and kinematics were recorded using an instrumented treadmill and 3D Motion Capture. Statistical parametric mapping was used for analysis.cHRA improved the median Harris Hip Score from 63 to 100, Oxford Hip score from 27 to 48 and the MET from 5.7 to 10.3. cHRA improved top walking speed (5.75km vs 7.27km/hr), achieved a more symmetrical ground reaction force profile, (Symmetry Index value: 10.6% vs 0.9%) and increased hip range of motion (ROM) (31.7° vs 45.9°). Postoperative data was not statistically distinguishable from the healthy controls in any domain.This gait study sought to document the function of a novel ceramic hip resurfacing, using those features of gait commonly used to describe the shortcomings of hip arthroplasty. These features were captured before and 12 months following surgery. Preoperatively the gait patterns were typical for OA patients, while at 1 year postoperatively, this selected group of patients had gait patterns that were hard to distinguish from healthy controls despite an extended posterior approach. Applications for regulatory approval have been submitted.

Outcomes of Birmingham Hip Resurfacing Based on Clinical Aspects and Retrieval Analysis of Failed Prosthesis.

This research aims to identify the prevalence of failure for Birmingham Hip Prosthesis (BHR) in total hip arthroplasty and to analyze its reasons from biomaterials and biofunctional perspectives. We present our current analysis and tests on a series of different BHR-retrieved prostheses after premature failure. Relevant clinical data, such as X-ray investigations and intraoperative images for clinical case studies, were analyzed to better understand all factors involved in BHR prosthesis failure. A detailed analysis of the failures highlighted uneven cement distribution, overloading in certain areas, and void formation in the material. A closer investigation using microscopical techniques revealed the presence of a crack originating from the gap between the cement mantle and human bone. Additionally, scanning electron microscopy analyses were conducted as part of the investigation to examine bone cement morphology in detail and better understand the interactions at the interfaces between implant, cement, and bone. In conclusion, this research emphasizes the importance of surgical technique planning and the cementation procedure in the success rate of BHR prostheses. It also underscores the need to carefully evaluate patient characteristics and bone quality to minimize the risk of BHR prosthesis failure. The cementation procedure seems to be essential for the long-term functionality of the BHR prosthesis.

Return to surfing following hip arthroplasty.

To date, no previous studies have explored return to surfing after hip arthroplasty. The objective of this study is to analyse return to a risky activity following hip arthroplasty. A retrospective chart review was conducted on all primary total hip arthroplasties (THA) and hip resurfacing arthroplasties (HRA) performed by the senior author from 2014 to 2021. Patients identified as surfers were contacted to complete a survey including surfing history and patient-reported outcomes. 83 hips in 67 patients were contacted. There were 66 THAs and 17 HRAs. 81 hips were performed through a posterior approach and 2 through an anterior approach. At an average of 67 months, there were no dislocations and no patients reported hip pain while surfing. Time to resume surfing was a median of 16 (range 8-144) weeks. Among 13 patients who did not return to surfing, 8 cited new lifestyle restrictions, 4 attributed it to other arthritic joints, and only 1 patient attributed their limitation to the replaced hip. This group had taken significantly more time off from surfing prior to surgery. Return to surfing following THA and HRA is common and safe in our study population with no complications and specifically no dislocations. Patients with other sites of arthritis and patients who have more extensive time away from surfing prior to surgery are less likely to return to sport. While surfing is clearly not without risk, patients can generally expect a high rate of successful return to surfing after hip arthroplasty.

Mid to long-term survivorship of hip arthroplasty in patients 40 years and younger

BackgroundEtiology of hip osteoarthritis (OA) and survival of hip arthroplasty in the young (below 40-years-old) remains poorly described. Furthermore, joint survivorship mid to long-term and PROMs according to the etiology are unclear. The study aims were to 1) identify the indications for arthroplasty in the below 40-years-old cohort; 2) define hip arthroplasty outcomes in the young and 3) test whether patients with sequelae of pediatrics hip disease have inferior outcome compared to other patients. HypothesisOur hypothesis was that hip arthroplasty is a viable option for managing hip disease in patients under 40, with excellent survival rates and outcomes. Material and methodsThis is an IRB approved, retrospective, consecutive, multi-surgeon, cohort study from a single academic center. Indication for hip arthroplasty of 346 patients (410 hips) below 40-years-old were studied; 239 underwent THA (58%) and 171 hip resurfacing (42%). Patient, surgical and implant factors were tested for association with implant survivorship and functional outcome for hip arthroplasty performed with a follow-up of more than two years. Pediatric hip sequelae patients were compared for survival and PROMs with the rest of the cohort. ResultsThe most common etiology of OA was FAI (47%), followed by pediatric hip sequelae (18%). The 10-year survivorship was 97.2% ± 1.2, mean OHS was 45.1 ± 6.3 and mean HHS was 93.4 ± 12.6. The pediatric hip sequelae subgroup demonstrated no differences in 10-year survivorship and better PROMs compared to rest (OHS: 46.6 ± 3.8; HHS: 96.0 ± 8.5). DiscussionThe most common aetiologies amongst the young with hip OA is FAI and pediatric hip sequelae. Hip arthroplasty in the young presents excellent 10-year survivorship and PROMs. Excellent survival and PROMs in the young with pediatric hip sequelae provide important information for decision-making in this challenging population. Level of evidenceIII; retrospective cohort study.

Metal-on-metal hip resurfacing arthroplasty: is it safe and reliable? A synopsis of the past, the present, and the future of HRA.

This paper discusses the existing literature in the field of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), the background (why was it developed), the past (what was the evidence leading to its rise and fall in clinical use), the present situation (why a potential resurgence), and the future directions for potential improvements. All literature relevant to MoM HRA was reviewed and summarized to provide a comprehensive summary. Furthermore, a detailed literature search was performed on PubMeD, MEDLINE, and Google Scholar to identify all clinical studies reporting a minimum 10 years of outcomes for modern MoM HRA devices from February 2018 to February 2023. In addition, joint registry data over the same time period, available in the public domain, was examined to extract related information on MoM HRA. Metal ions are present in almost all types of hip replacement; on the whole, however, the risk of revision for resurfacing due to metal-related pathologies is very low, but higher than in other types of bearings. There are studies that show that some brands of MoM resurfacing prostheses have achieved excellent clinical outcomes in long-term follow-up studies and are still in use although less commonly than in early 2000s. Use of alternative bearing surfaces has demonstrated excellent results in the short-term and a very critical long-term follow-up of these cases still will help establish their place in the hip arthroplasty world. HRA deserves a permanent place in the armamentarium of orthopedic surgeons and in the hand of experienced surgeons.

Establishing minimal clinically important differences and patient acceptable symptom state thresholds following birmingham hip resurfacing

IntroductionBirmingham Hip Resurfacing (BHR) has emerged as a compelling and innovative alternative to total hip arthroplasty (THA), especially among young, active patients. However, the Minimal Clinically Important Difference (MCID) and the Patient Acceptable Symptom State (PASS) thresholds have not yet been determined for patients undergoing BHR. Therefore, the current study aimed to (1) determine the MCID and PASS thresholds for both the Hip disability and Osteoarthritis Outcome Score (HOOS)-Pain and HOOS physical function shortform (PS), for patients who underwent BHR; and (2) identify factors influencing the achievement of MCID and PASS for HOOS-Pain and HOOS-PS.MethodsProspectively collected data from patients undergoing BHR was analyzed. Patients with osteoarthritis and completed preoperative and 1-year postoperative PROMs were included. Distribution-based and anchored-based approaches were used to estimate MCID and PASS, respectively. The optimal cut-off point for PASS thresholds was calculated using the Youden index.ResultsMCID for HOOS-Pain and PS were calculated to be 9.2 and 9.3, respectively. The PASS threshold for HOOS-Pain and PS were ≥ 77.7 and ≥ 87.3, respectively. The current study identified several factors affecting postoperative achievement of thresholds. Baseline Mental Component Summary (MCS) scores were a predictor for achieving MCID for postoperative HOOS-Pain, achieving MCID for postoperative HOOS-PS, achieving PASS for postoperative HOOS-Pain, and achieving PASS for postoperative HOOS-PS. Furthermore, baseline HOOS-Pain was a significant predictor for achieving MCID for postoperative HOOS-PS, achieving PASS for postoperative HOOS-Pain, and achieving PASS for postoperative HOOS-PS.ConclusionsMCID and PASS thresholds were established for HOOS-Pain and PS domains following BHR with most patients achieving these clinically meaningful benchmarks. Additionally, several factors affecting achievement of MCID and PASS were identified, including modifiable risk factors that may allow clinicians to implement optimization strategies and further improve outcomes.

Conversion of hip resurfacing to total hip arthroplasty: is the outcome closer to primary or revision total hip arthroplasty?

BackgroundAlong with the advent of newer bearings, hip resurfacing (HR) is gaining renewed interest as a bone sparing alternative to conventional total hip arthroplasty (THA) in young patients. However, the outcome of conversion of failed HR to THA (HRc) remains sparsely described. This study aimed to compare the outcomes and complication rates of HRc to those of primary (pTHA) and revision THA (rTHA) to find out to which group HRc is most comparable. HypothesisThe study hypothesis was that the outcomes and complications rates of HRc were closer to those of pTHA than rTHA. Materials and methodsBetween 2001 and 2011, a continuous series of 207 HR were prospectively included in our institutional registry and retrospectively analyzed. Out of them, 17 HR (8%) were converted to THA. Propensity scores were used to match patients in the HRc group to the pTHA and the rTHA groups using a greedy 1:3 matching procedure (51 pTHA and 51 rTHA). Clinical and radiographic outcomes, perioperative data and complications were analyzed and compared between the three groups. ResultsNo significant difference between HRc and pTHA was observed in terms of clinical and functional outcomes, duration of surgery, acetabular component diameter and length of hospital stay (p = 0.13 to 0.94). Perioperative blood loss was significantly lower for pTHA than for HRc (p = 0.01). HRc demonstrated significantly higher HHS and HOOS scores than for rTHA at one year (p = 0.03 and p < 0.01, respectively). Duration of surgery was significantly lower in HRc compared to rTHA (p = 0.02) while length of hospital stay was similar (p = 0.84). Complication rate was significantly higher in the rTHA group, compared to HRc and pTHA groups (37.3 vs. 29.4 vs. 11.8%, p = 0.01). ConclusionThis study demonstrated that the clinical and functional outcomes of HRc were closer to those of pTHA than those of rTHA, though complication rate was higher than for pTHA. Level of evidenceIII; Retrospective comparative study

Revision of metal-on-metal hip replacements with dual-mobility bearings and acetabular component retention.

In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications.

Examining the "revisability" benefit of hip resurfacing arthroplasty.

Hip resurfacing arthroplasty (HRA) is an alternative to total hip arthroplasty (THA) that is typically reserved for young active patients because it preserves bone. However, the benefits of HRA only hold true if conversion THA after failed HRA provides acceptable outcomes. To compare patient reported outcomes for conversion THA after HRA failure to primary THA. A retrospective review of 36 patients (37 hips) that underwent conversion THA for failed HRA between October 2006 and May 2019 by a single surgeon was performed. Patient reported outcomes [modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity score] were obtained via an email-based responder-anonymous survey. Outcomes were compared to normative data of a primary THA cohort with similar demographics. Subgroup analysis was performed comparing outcomes of conversion THA for adverse local tissue reaction (ALTR) vs all other causes for failure. The study group had a lower mHHS than the control group (81.7 ± 13.8 vs 90.2 ± 11.6, P < 0.01); however, both groups had similar UCLA activity levels (7.5 ± 2.3 vs 7.2 ± 1.6, P = 0.51). Patients that underwent conversion for non-ATLR causes had similar mHHS (85.2 ± 11.5 vs 90.2 ± 11.6, P = 0.11) and higher UCLA activity levels (8.5 ± 1.8 vs 7.2 ± 1.6, P < 0.01) compared to the control group. Patients that underwent conversion for ATLR had worse mHHS (77.1 ± 14.5 vs 90.2 ± 11.6, P < 0.01) and UCLA activity levels (6.1 ± 2.3 vs 7.2 ± 1.6, P = 0.05) when compared to the control group. Patient outcomes equivalent to primary THA can be achieved following HRA conversion to THA. However, inferior outcomes were demonstrated for ALTR-related HRA failure. Patient selection and perhaps further studies examining alternative HRA bearing surfaces should be considered.

Birmingham Hip Resurfacing at 25 years.

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. 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. 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). 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.

Two-Year Results of Ceramic-on-Ceramic Hip Resurfacing in an International Multicenter Cohort

BackgroundHip resurfacing arthroplasty (HRA) is a bone-conserving alternative to total hip arthroplasty. We present the 2-year clinical and radiographic follow-up of a novel ceramic-on-ceramic HRA in an international multicenter cohort. MethodsPatients undergoing HRA between September 2018 and January 2021 were prospectively included. Patient-reported outcome measures (PROMs) in the form of the Forgotten Joint Score, Hip Disability and Osteoarthritis Outcome Score Jr., Western Ontario and McMaster Universities Arthritis Index, Oxford Hip Score, and University of California, Los Angeles, Activity Score were collected preoperatively, and at 1 and 2 years postoperation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis or loosening, and heterotopic ossification formation. ResultsThe study identified 200 patients who reached a minimum 2-year follow-up (mean 3.5 years). Of these, 185 completed PROMs follow-up at 2 years. There was a significant improvement in Hip Disability and Osteoarthritis Outcome Score (P < .001) and Oxford Hip Score (P < .001) between the preoperative, 1-year, and 2-year outcomes. Patients had improved activity scores on the University of California, Los Angeles, Active Score (P < .001), with 45% reporting a return to high-impact activity at 2 years. At 1 and 2 years, the Forgotten Joint Score was not significantly different (P = .38). There was no migration, osteolysis, or loosening of any of the implants. No fractures were reported over the 2-year follow-up, with only 1 patient reporting a sciatic nerve palsy. There were 2 revisions, 1 for unexplained pain at 3 months due to acetabular component malposition and 1 at 33.5 months for acetabular implant failure. ConclusionsThe ceramic-on-ceramic resurfacing at 2 years postoperation demonstrates promising results with satisfactory outcomes in all recorded PROMs. Further long-term data are needed to support the widespread adoption of this prosthesis as an alternative to other HRA bearings.

Advances in imaging for pre-surgical planning in hip resurfacing arthroplasty

BackgroundAccurate preoperative templating is essential for the success of hip resurfacing arthroplasty (HRA). While digital radiograph is currently considered the gold standard, stereoradiograph and CT converted 3D methods have shown promising results. However, there is no consensus in the literature regarding the preferred modality for HRA templating, and angular measurements are often overlooked. Thus, this study aimed to: (1) compare the performances of different modality in implant sizing and angle measurements, (2) evaluate the measurement reproducibility, (3) assess the impact of severe osteoarthritis on femoral head sizing, and (4) based on the analysis above, explore the optimal imaging and planning strategy for HRA. HypothesisAn optimal imaging modality exists for HRA planning regarding implant sizing and angular measurements. Materials and methodsPreoperative imaging data from seventy-seven HRA surgeries were collected. Three raters performed templating using digital radiograph, stereoradiograph, and CT converted 3D models. Measurements for femoral head size, neck-shaft angle, and calcar-shaft angle were obtained. The femoral head sizing was compared to the intraoperative clinical decision. The reproducibility of measurements was assessed using the intraclass correlation coefficient (ICC). Correlations were examined between sizing disagreement and osteoarthritis grade (Tonnis Classification). ResultsDigital radiograph, stereoradiograph, and 3D techniques predicted one size off target in 27/77 (35%), 49/70 (70%), and 75/77 (97%) of cases, respectively, corresponding to 1.8±1.6 (0 to 5.67), 0.9±0.7 (0 to 2.67), and 0.4±0.4 (0 to 1.67) sizes off target, indicating statistically significant differences among all three modalities, with p-values all below 0.01. There were no statistically significant differences among the different modalities for angular measurements. Measurements showed moderate to excellent reproducibility (ICC=0.628–0.955). High-grade osteoarthritis did not impact image sizing in any modality (r=0.08–0.22, all p>0.05). DiscussionCT converted 3D models were more accurate for implant sizing in HRA, but did not significantly outperform other modalities in angular measurements. Given the high costs and increased radiation exposure associated with CT, the study recommended using CT scans selectively, particularly for precise femoral head sizing, while alternative imaging methods can be effectively used for angular measurements. Level of evidenceIII; retrospective comparative diagnostic study.

SURVIVORSHIP OF CURRENTLY AVAILABLE METAL-ON-METAL HIP RESURFACING IN MALES UNDER 55 YEARS OF AGE: A MATCHED NJR SURVIVORSHIP ANALYSIS

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 &gt;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&lt;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.

Registre français du resurfaçage de hanche : un registre observationnel exhaustif ?

Introduction: The resurfacing hip prosthesis (RH) combines a double questioning, namely of course the confirmation of the interest in this prosthetic concept of “preservation of bone capital”, but also the merits of the methodology for the implementation place and management of an exhaustive collection of clinical data, in the form of a true “national observational register of hip resurfacing”…Material & methods: It should be noted in the early 2000s that there was considerable uncertainty about the future of hip resurfacing. In this context, the CNP-COT was in favor of maintaining this prosthetic option, under cover of the launch of an exhaustive observational register in 2015 and the creation of an approved Training Center for France.This French hip resurfacing registry is therefore an observational, non-comparative, prospective, multicenter, 1-arm study, conducted open-label with exhaustive inclusion in patients treated consecutively by total hip arthroplasty with a resurfacing prosthesis.Results: The completeness of the patients included in the resurfacing register is verified by comparison, over the inclusion period considered, on the one hand (1) between the details of invoicing for the different RH implants delivered to the different fitting centers and on the other part (2) for each of the surgeons participating in the study, to their inclusion in the RRH register within the OrthoWave™ online databaseDiscussion: The objectives set by the Supervisory Authorities (HAS, CNP-COT) and the French Hip and Knee Society (SFHG) were validated, with a completeness rate of 93.47% when the HAS file was created, and a survival rate of over 98% for 3592 prostheses after 8 years. Note also a very low complication rate (<1%) with notably absence of dislocations or allergic phenomena to metal ions.Conclusion: The highlight of this study underlines the interest of this management of a specific exhaustive observational register within the French Society of Hip and Knee Surgery, which made it possible to perpetuate the possibility of implanting hip resurfacing in France.Level of evidence: IV

Effect of Elevated Acetabular Cup on Contact and Failure Analysis in Hip Implants for Different Microseparations and Cup Inclinations Under Routine Gait Activities Using In Silico Approach.

The acetabular cup design plays a critical role in reducing contact stress between femur head acetabular cup. Many studies used ellipsoidal and spheroidal geometry in acetabular cup design to effectively reduce contact stress. The present study focuses on elevated acetabular cup rim with round corner design to reduce contact stress with round corner geometry. The cobalt chromium femur head and cup are considered for finite element (FE) model of hip resurfacing. The gait loads of routine activities of humans like normal walking, stair ascending and descending and sitting down and getting up gait activities are applied to the developed 3D FE model. Five microseparations of 0.5, 1, 1.5, 2 and 2.5mm are considered in the present study. The acetabular cup inclination angle considered for this study are 35°, 45°, 55°, 65° and 75°. The contact stress and von Mises stress plot for each gait activities under these microseparations are analyzed for betterment of longevity of implants. Overall elevated cup rim design helped in reducing contact stress to a greater extent than conventional cup with different geometries. Also, the predicted von Mises stress for all the parameters considered in the current study are well within the yield strength of CoCr material. Therefore, elevated cup rim could be used as a better alternative to spline and, ellipsoidal and circular geometries of cup.