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

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

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 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

Purpose. Elevated blood metal ions are associated with the early failure of the Hip Resurfacing Arthroplasty. The aim of this study was to analyse our prospective database of Hip Resurfacing Arthroplasty patients, to independently review the outliers with elevated blood metal ions and to determine whether a screening program would be of value at our institution. Method. In 2004 a ten year prospective longitudinal study was set up to evaluate the clinical effectiveness and safety of Metal on Metal Hip Resurfacings in young, active adults with degenerative hip disease. Six hundred and four patients have enrolled in this multi-surgeon prospective study with strict inclusion criteria for Hip Resurfacing Arthroplasty. All have received the same implant design. All have completed validated functional outcome questionnaires at baseline, three and six months, then annually. A sub-cohort of 196 patients underwent whole blood chromium and cobalt analysis at the same time periods. Metal on metal bearings have a running in period of a minimum of six months before a steady state wear pattern is attained. We chose five parts per billion for Cobalt or Chromium as our threshold value. This value corresponds to the workplace exposure limit in the United Kingdom to Cobalt in whole blood. Therefore patients with ion levels greater than five parts per billion after six months were recalled for independent review, including further metal ion analysis. Results. Twenty two patients were recalled. Twenty one patients (32 Hip Resurfacing Arthroplasties) were reviewed. At latest review 11 patients (15 Hip Resurfacing Arthroplasties; eight females) had levels greater than five parts per billion. Mean follow up was 59.8 months (47–78). Mean age at surgery was 48.7 years (37–55). Median femoral component size was 50 millimetres (42–54). Mean acetabular anteversion was 18.3 degrees (−5.2 43.0). Mean acetabular inclination was 46.1 degrees (33.1–57.1). Mean cobalt and chromium levels were 8.82 parts per billion (3.49 18.42) and 9.15 parts per billion (3.79 24.33). Patients with ion levels greater than five parts per billion were associated with inferior functional scores (p= 0.018), inferior hip flexion (p=0.01) and mal-positioned acetabular components (p=0.023). All symptomatic patients were female. Conclusion. It is reassuring that the majority do not have elevated metal ions (185/196; 94.4%). That said, blood metal ion screening of Hip Resurfacing Arthroplasties aids in the early detection of problematic cases. Comprehensive clinical review should follow as patient safety is paramount. The early detection of problematic cases is advantageous to the surgeon and patient. Revision surgery for an established pseudotumour has been found to be technically challenging, often with a poor outcome

Strategy regarding patella resurfacing in total knee replacement (TKR) remains controversial. TKR revision rates are reportedly influenced by surgeon procedure volume. The study aim was to compare revision outcomes of TKR with and without patella resurfacing in different surgeon volume groups using data from the AOANJRR. The study population included 571,149 primary TKRs for osteoarthritis. Surgeons were classified as low, medium, or high-volume based on the quartiles of mean primary TKR volume between 2011 and 2020. Cumulative percent revision (CPR) using Kaplan-Meier estimates of survivorship were calculated for the three surgeon volume groups with and without patella resurfacing. Cox proportional hazards models, adjusted for age and sex, were used to compare revision risks. High-volume surgeons who did not resurface the patella had the highest all-cause CPR (20-year CPR 10.9%, 95% CI [10.0%, 12.0%]). When the patella was resurfaced, high-volume surgeons had the lowest revision rate (7.3%, 95% CI [6.4%, 8.4%]). When the high-volume groups were compared there was a higher rate of revision for the non-resurfaced group after 6 months. When the medium-volume surgeon groups were compared, not resurfacing the patella also was associated with a higher rate of revision after 3 months. The low-volume comparisons showed an initial higher rate of revision with patella resurfacing, but there was no difference after 3 months. When only patella revisions were considered, there were higher rates of revision in all three volume groups where the patella was not resurfaced. TKR performed by high and medium-volume surgeons without patella resurfacing had higher revision rates compared to when the patella was resurfaced. Resurfacing the patella in the primary procedure protected against revision for patella reasons in all surgeon volume groups. Level of evidence: III (National registry analysis)

Introduction. Hip Resurfacing Arthroplasty (HRA) has been performed in the United States for over 10 years and is an alternative to standard Total Hip Arthropastly (THA). It is appealing to younger patients with end stage osteoarthritis who seek to maintain active lifestyles. Benefits of HRA versus THR include a larger femoral ball size, potential to return to impact activities, decreased dislocation rates, and restoration of normal hip biomechanics. Patients ≤50 years old are a particularly challenging patient group to treat with THA because of their young age and high activity level, and as such, are well-suited for HRA. However, there are limited reports in the literature about clinical, radiographic and functional outcomes for this patient cohort. We present results of a clinical investigation at our institution for this patient cohort with minimum 5-year follow up, including long term survivorship and outcome scores. Methods. HRA, using the Birmingham Hip Resurfacing (BHR), was performed for 538 procedures between 2006–2009 by a single surgeon at a United States teaching hospital. After Institutional Review Board approval, medical and radiographic study records were retrospectively reviewed. Harris Hip Scores (HHS) were routinely collected. Patients who had not returned for follow-up examination were contacted by telephone for information pertaining to their status and implant, and a modified HHS was also administered. A Kaplan Meier survival curve was constructed to evaluate time to revision. Statistical analysis was performed (SAS version 9.3; SAS Institute, Cary, NC). Results. Of the 538 patients who underwent HRA from 2006–2009, 238 were aged ≤50 years (44%). Five-year follow up data was obtained from 209 of these patients (88%), using medical record documentation, and telephone survey as needed. The mean follow-up for all patients was 6 years (range 5–8 years). A total of 3% (8/238) were revised. Reasons included: (i) femoral loosening in 4, (ii) Iliopsoas impingement in 1, (iii) metallosis/adverse tissue reaction in 1, (iv) femoral neck fracture following motor vehicle accident in 1, and (v) unknown reasons in 1. Of the 238 patients, 55 (23%) were female, 2 (2/55; 3.6%) of whom have since undergone revision surgery for either metallosis/adverse tissue reaction, or unknown reasons. Of the 53 women who retained their BHR at 5-year follow up, the average HHS was 96.5. Of the 238 patients, 183 (77%) were male patients, 6 (6/183; 3.2%) of whom have since undergone revision surgery for femoral component loosening, iliopsoas impingement, or femoral neck fracture sustained in a motor vehicle accident. At 5-year follow-up, 177 male patients retained their implant and had an average Harris Hip Score of 98.8. The overall implant survival was 96.6% at approximately 5 years. Conclusion. In our cohort of patients aged ≤50 treated with BHR [Fig. 1], our results demonstrated 5-year survivorship of 96.6%, with average HHS of 98.8 in males and 96.5 in females. This study demonstrates HRA is a successful alternative to traditional THA in a challenging cohort of younger, active patients

Introduction. Patients presenting with osteoarthritis as late sequelae following pediatric hip trauma have few options aside from standard Total Hip Replacement (THR). For younger more active patients, Hip Resurfacing Arthroplasty (HRA) can be offered as an alternative. HRA has been performed in the United States over the past decade and allows increased bone preservation, decreased hip dislocation rates versus THR, and potential to return to full activities. Patients presenting with end-stage hip arthritis as following prior pediatric trauma or disease often have altered hip morphology making HRA more complicated. Often Legg-Calve-Perthes (LCP) patients present with short, wide femoral necks, and femoral head distortion including coxa magna or coxa plana. There often can be acetabular dysplasia in conjunction with the proximal femoral abnormalities. Slipped Capital Femoral Epiphysis (SCFE) patients have an alteration of the femoral neck and head alignment, which can make reshaping the femoral head difficult. In particular, the femoral head is rotated medially and posteriorly, reducing the anterior and lateral offset. We present a cohort of 20 patients, with history of a childhood hip disorder (SCFE or LCP), who underwent HRA to treat end-stage arthritis. Fifty percent had prior pediatric surgical intervention at an average age of 11. Method. After Institutional Review Board approval, data was reviewed retrospectively on patients with pediatric hip diseases of SCFE and LCP who underwent HRA using the Birmingham Hip Resurfacing (BHR) by a single orthopaedic surgeon at a teaching institution. Harris Hip Scores (HHS), plain radiographs and blood metal ion levels were reviewed at routine intervals (12 months and annually thereafter). Those who had not returned for recent follow-up were contacted via telephone survey for a modified HHS. Results. Twenty patients had mean follow up of 2.8 years (range 1–7 years). Twelve had LCP and 8 SCFE. Median implant duration was 2.4 years. One-year metal ion testing revealed median chromium level of 2.3 ppb and median Cobalt level of 1.5 ppb. At one-year follow up, plain radiographs demonstrated all patient implants to be well-fixed, without radiolucent lines or osteolysis. Two patients at three and five-year follow-up exhibited heterotopic ossification. Mean HHS for LCP at 6 weeks post-operative was 88, and 98 at one year. Mean HHS for SCFE at 6 weeks post-operative was 77.5, and 98.6 at one year. LLD was significantly improved with an average pre-operative LLD of 12.6 mm and post op of 2.6 mm (p-value <0.001). At most recent follow-up, all retained their implants with overall average HHS of 98. Conclusion. At minimum of one-year following HRA, an increase in functional outcomes is found in patients who underwent HRA for osteoarthritis associated with LCP and SCFE with a mean HHS of 98. No increase was found in complications including femoral neck fracture or implant loosening despite technical challenges of the procedure related to proximal femoral morphologic abnormalities, or presence of acetabular dysplasia [Fig 1]

My experience with Birmingham Hip Resurfacing began in July 2000 and continues to this day for selected cases including OA, AVN, CDH and also following old fracture deformity and Femoral/Pelvic osteotomy. Early on, the criteria for patient selection expanded with increasing experience and positive acceptance by patients but then moderated as adverse reports including those from our National Joint Replacement Registry suggested a need for caution with Surface Replacement. Over 10 years, (July 2000 — July 2010), a personal series of 243 BHRs were followed (169 male — 74 female) with only one return to theatre in that time (4 days post op. to revise a poorly seated acetabular cup in a dysplastic socket). There were no femoral neck fractures in that 10 year period but 3 femoral cap/stem lucencies were known (2 female-1 male) with insignificant symptoms to require revision. The complete 10 year series of cases were then matched in the Australian National Joint Replacement Registry. No other revisions were identified by the Registry for all 243 cases. Soon after completing this encouraging outcome study however 3 revision procedures have been necessary (2 for sudden late head/neck failure including one of the three with known cap/stem lucencies and one for suspected pseudotumour/ALVAL). One healing stress fracture of the femoral neck and another further cap/stem loosening have also presented recently but with little in the way of symptoms at this stage. Surprisingly, there is little indication which case is likely to present with problems even in the presence of many cases done earlier where one would be cautious now to use a BHR but which have ongoing good outcomes. (e.g., AVN or the elderly osteoporotic patient). My journey therefore with Birmingham Hip Resurfacing over that first 10 years has been very positive and I believe it retains an important place for the younger patient with good bone quality. However it has become only recently apparent in my series of 243 cases that late onset unpredictable problems can arise which is likely to further narrow my selection criteria for this procedure. The likely outcome will be that it will have a more limited place in my joint replacement practice despite the very positive early experience

Purpose. This study was performed to evaluate clinical and radiographic outcomes of Hip Resurfacing Arthroplasty for treatment of haemophilic hip arthropathy. Material & Method. Between 2002 and 2013, 17 cases of hip resurfacing arthroplasties were performed in 16 haemophilic patients (13 cases of haemophilia A, 2 cases of haemophilia B, 2 cases of von Willebrand disease). The average age of the patients was 32.5(range: 18∼52) years. The average follow up period from the operation was 6.3 (range: 2∼13) years. In this study, the subjects that completed follow-up were composed of 5 cases composed of patients who were treated with Conserve plus. ®. hip resurfacing system, 5 cases composed of patients who were treated with Durom. ®. hip resurfacing system, 4 cases who were treated with ASR. ®. hip resurfacing system, and 3 cases who were treated with Birmingham. ®. hip resurfacing system. The Modified Harris hip score, the range of motion of the hip joint, perioperative coagulation factor requirements and complications associated with bleeding were evaluated as part of the clinical assessment. For the radiographic assessment, fixation of component, presence of femoral neck fracture, osteolysis, loosening and other complications were evaluated. Results. The modified Harris hip score improved from 65.4(47–80) points before surgery to 97.8(90–100) points at the last follow-up. The average further flexion improved from 103° (70–135) to 110°(80–130) after surgery. The average abduction improved from 22.4° (0–45) to 41.3° (20–50) after surgery. All the patients showed a significant reduction in pain. The mean requirement of factor VIII reduced from 2470 units per month before surgery to 1125 units per month at the time of the last follow-up. However, in the case of high-titer inhibitor to factor VIII, haemophilia B, von Willebrand disease, the average monthly factor requirement was not changed due to bleeding episode of other joints. There was two cases of re-bleeding. There were no femoral neck fracture, no osteolysis, and no implant loosening in last follow up. Conclusion. Hip resurfacing arthroplasty for haemophilic hip arthropathy in patients with mild deformity or relatively preserved range of the hip joint motion can bring reliable pain relief, functional improvement, and reduction of factor requirement for over two years follow-up study. However, bleeding-associated complications are a cause for concern, especially for patients with antibodies against coagulation factors

Humeral resurfacing arthroplasty has been advocated as an alternative to stemmed humeral component designs given its ability to preserve proximal bone stock. Further, these implants have become more attractive given the possibility of stem-related complications including humeral fracture, stress shielding, and osteolysis; complications that may necessitate fixation, revision to long stem components, or reverse total shoulder arthroplasty. As more total shoulder arthroplasties are performed in younger patient populations, the likelihood of increased revision procedures is inevitable. Maintaining proximal bone stock in these cases with use of a resurfacing arthroplasty not only facilitates explant during revision arthroplasty, but preservation of proximal metaphyseal bone facilitates reimplantation of components. Clinical results of these resurfacing components have demonstrated favorable results similar to stemmed designs. Unfortunately, resurfacing arthroplasty may not be as ideal as was hoped with regard to recreating native humeral anatomy. Further, resurfacing arthroplasty may increase the risk of peri-prosthetic humeral fracture, and lack of a formal humeral head cut makes glenoid exposure more difficult, which may be associated with a higher degree of neurovascular injury. Stemless humeral components are designed for strong metaphyseal fixation and avoid the difficulty with glenoid exposure seen in resurfacing designs, as these components require a formal humeral head cut. Early clinical outcomes of a single stemless design demonstrated significant improvements in clinical outcome scores, without evidence of component migration, subsidence or loosening. The only mid-term clinical results of stemless design implants are seen with the Arthrex Eclipse system (Arthrex, Naples, FL). In a prospective study involving 78 patients at 5-year follow-up, significant improvements were observed in clinical outcome scores. While there was evidence of proximal stress shielding in an older population, this did not influence shoulder function. The overall revision rate was 9% at 5 years, with no component necessitating revision as a result of humeral component loosening. Resurfacing arthroplasty and stemless humeral components in total shoulder arthroplasty remain attractive options to preserve proximal metaphyseal bone stock, avoiding stem-related complications. Early and mid-term clinical outcomes are comparable to stemmed designs and demonstrate no evidence of humeral component loosening

Introduction. Recently used hip resurfacing systems remove bone, ream away the subchondral bone stock and reduce biomechanical properties of the femoral neck. Since much bone was removed from the head, the biomechanical properties decrease. The Onlay Resurfacing technique preserves complete bone stock and individual anatomy without any change in offset or leg length. To quantify the clinical outcome and adverse events a group receiving standard total hip arthroplasty was designed as control. Methods. 104 patients with primary osteoarthritis underwent hip onlay resurfacing. Mean aged 51 years, BMI 27,2. An onlay resurfacing system with a cemented femoral cup and a modular cementless acetabular component was used for resurfacing. The control group (n:104) got a standard cementless THA with a standard head size of 32 mm in diameter. All procedures were performed by one surgeon and the same minimal invasive antero lateral approach was used. An identical post-operation procedure with regards to rehabilitation, physiotherapy and medication was performed in both groups. The Harris Hip Score was designed as the primary criteria. Results. In the Onlay Resurfacing group the HHS improved six weeks, six months and three years after surgery from 46 to 89, to 95 and 97 after three years. Compared to resurfacing the THA improved from 42 to 85, to 92 and 93 after three years. At six months and three years, the SF12 score (mental and physical) improved to normal in both groups. One neck fracture and one aseptic loosening occurred in the onlay resurfacing group, one DVT and 1 dislocation were found in the control group. No implant failure in both groups and no difference in blood loss. The mean leg length after standard THA shows 0.4 mm lengthening in contrast to resurfacing without statistic significant difference. Conclusion. Hip onlay resurfacing preserves maximal bone stock and provides excellent functional outcome. The outcome was better in the onlay resurfacing group compared to standard THA. Combined with minimal invasive surgery patients will be able to shorten the rehab phase significantly. Side effects such as luxation, instability and length differences were expected to appear less frequently but adverse events typically related to resurfacing such as neck fracture occur. Because of the modularity of the onlay resurfacing system, revisions of the femoral component could be done as a primary hip arthroplasty

Hip Resurfacing in its current metal on metal hybrid fixation form has been performed in large numbers in Australia since 1999. Outcomes from the Australian Orthopaedic Association National Joint Replacement Registry are shown. While there is a wide range of outcomes these can be shown to depend on patient factors and implant factors. Use of one of the successful implants (for example the Birmingham Hip) in a young male patient with osteoarthritis by a suitably trained surgeon can lead to good results. In the AOA NJRR the 10 year cumulative percent revision rate for the Birmingham Hip in male patients under the age of 60 at the time of surgery is 3.3%

Introduction. Advantages of ceramic materials for hip joint prosthesis are recognized to be high hardness, scratch resistance, improved wettability, lower friction and lower wear than CoCr surfaces. Recent studies suggest the use of ceramic femoral head reduce fretting corrosion at stem taper junction compared to metal-on-metal taper junction[1]. Continuous improvement of ceramic materials for orthopedic lead to the development of a resurfacing ceramic-on-ceramic hip joint prosthesis. The main differences of resurfacing heads respect to standard heads are their anatomical dimension and the empty shape suitable to cover the femoral bone and to connect with the resurfacing stem. Ceramic is essentially a brittle material and its strength is influenced by the minimum thickness in the stressed area. Ceramic resurfacing head minimum thickness is comparable with ceramic revision head already on the market. The aim of this study is to develop a mechanical pre-clinical analysis verification process for the newly developed system. Materials and methods. The empty shape of the ceramic resurfacing head may influence its strength in a crush loading scenario. Although this is not a physiological condition this test represents the most severe loading for a resurfacing head. Also comparative analysis can be done considering the yield point of conventional metal resurfacing heads reported by the FDA Center for Devices and Radiological Health. For this reason a static unsupported head strength test is performed by applying a compressive load perpendicular to the head axis along the equatorial plane[2](Fig.1). Resurfacing ceramic head made in ZTA is suitable both for a resurfacing stem and an adaptor to be coupled with a standard stem. Mechanical test was performed on worst case resurfacing head size both with resurfacing stem and standard stem based and on FE non linear analysis performed in ANSYS 17.2 according the following material properties: ZTA ceramic (modulus of elasticity E, Poisson ratio ν and density ρ of 348GPa, 0.23 and 4.25g/cm. 3. respectively), and Ti6Al4V (E=114GPa, ν=0.33 and ρ=4.43g/cm. 3. ). For comparison purposes unsupported test was performed on standard head Ø28#S both in Biolox®Delta and Biolox®Forte ceramic. At least three components were used for each test and the average values was compared with predicates[2]. Static compressive load was applied with MTS hydraulic actuators with load cell of 100kN. Results. FE analysis indicated the larger resurfacing head as the worst case size in the size range(Fig.2). Static unsupported head strength test was performed on resurfacing ceramic head Ø57 coupled both with resurfacing stem and standard stem, Biolox®Delta head Ø28#S, Biolox®Forte head Ø28#S and respectively reached a strength value of 53±7kN, 90±3kN, 78±27kN, 49±1kN. Equivalent test were reported in literature for DeltaSurf® Ø58 and BHR. TM. , and respectively reached a strength of 26kN and 5.6kN. Discussion and Conclusion. LIMA ceramic resurfacing head and Biolox Forte Ø28#S showed equivalent unsupported head burst strength. LIMA ceramic resurfacing head showed higher unsupported head burst strength respect to DeltaSurf® and BHR. TM. highlighting its potential in clinical use. For any figures or tables, please contact the authors directly

Background. The management of the patella during primary total knee arthroplasty (TKA) is controversial. Despite the majority of patients reporting excellent outcomes following TKA, a common complaint is anterior knee pain. Resurfacing of the patella at the time of initial surgery has been proposed as a means of preventing anterior knee pain, however current evidence, including four recent meta-analyses, has failed to show clear superiority of patellar resurfacing. Therefore, the purpose of this study was to estimate the cost-effectiveness of patellar resurfacing compared to non-resurfacing in TKA. Methods. We conducted a cost-effectiveness analysis using a decision analytic model to represent a hypothetical patient cohort undergoing primary TKA. Each patient will receive a TKA either with the Patella Resurfaced or Not Resurfaced. Following surgery, patients can transition to one of three chronic health states: 1) Well Post-operative, 2) Patellofemoral Pain (PFP), or 3) Serious Adverse Event (AE), which we have defined as any event requiring Revision TKA, including: loosening/lysis, infection, instability, or fracture (Figure 1). We obtained revision rates following TKA for both resurfaced and unresurfaced cohorts using data from the 2014 Australian Registry. This data was chosen due to similarities between Australian and North American practice patterns and patient demographics, as well as the availability of longer term follow up data, up to 14 years postoperative. Our effectiveness outcome for the model was the quality-adjusted life year (QALY). We used utility scores obtained from the literature to calculate QALYs for each health state. Direct procedure costs were obtained from our institution's case costing department, and the billing fees for each procedure. We estimated cost-effectiveness from a Canadian publicly funded health care system perspective. All costs and quality of life outcomes were discounted at a rate of 5%. All costs are presented in 2015 Canadian dollars. Results. Our cost-effectiveness analysis suggests that TKA with patella resurfacing is a dominant procedure. Patients who receive primary TKA with non-resurfaced patella had higher associated costs over the first 14 years postoperative ($16,182 vs $15,720), and slightly lower quality of life (5.37 QALYs vs 6.01 QALYs). The revision rate for patellar resurfacing was 1.3%. If the rate of secondary resurfacing procedures is 0.5% or less, there is no difference in costs between the two procedures. Discussion. Our results suggest that, up to 14 years postoperative, resurfacing the patella in primary TKA is cost-effective compared to primary TKA without patellar resurfacing, due to the higher revision rate in this cohort of patients for secondary resurfacing. Our sensitivity analysis suggests that, among surgical practices that do not routinely perform secondary resurfacing procedures (estimated rate at our institution is 0.3%) there is no significant difference in costs. Although our results suggest that patella resurfacing results in higher quality of life, our model is limited by the availability and validity of utility outcome estimates reported in the literature for the long term follow up of patients following TKA with or without patella resurfacing and secondary resurfacing procedures

Resurfacing the patella is performed the majority of the time in the United States and in many regions it is considered standard practice. In many countries, however, the patella is left un-resurfaced an equal amount of the time or even rarely ever resurfaced. Patella resurfacing is not a simple or benign procedure. There are numerous negative sequelae of resurfacing including loosening, fragmentation, avascular necrosis, lateral facet pain, stress fracture, acute fracture, late fracture, and restricted motion. In a study by Berend, Ritter, et al, failures of the patella component were reported 4.2% of the time at an average of only 2.6 years. A study was undertaken at Washington University in recent years to determine rather more clinical problems were observed following total knee replacement with or without patella resurfacing. Records were maintained on all problem total knees cases with well localised anterior knee pain. The referral area for this clinic is St. Louis which is among the largest American cities, with the highest percentage of total knees that are performed without patella resurfacing. During 4 years of referrals of total knee patients with anterior knee pain, 47 cases were identified of which 36 had a resurfaced patella and 11 had a non-resurfaced patella. Eight of 36 resurfaced patellae underwent surgery while only 2 of 11 non-resurfaced patellae underwent subsequent surgery. More than 3 times as many painful total knees that were referred for evaluation had already had their patella resurfaced. In spite of the fact that approximately equal number of total knees were performed in this area without patella resurfacing, far more patients presented to clinic with painful total knee in which the patella had been resurfaced. The numerous pathologies requiring a treatment following patella resurfacing included patella loosening, fragmentation of the patella, avascular necrosis patella, late stress fracture, lateral facet pain, oblique resurfacing, and too thick of a patellar composite. In a large multi-center randomised clinical trial at 5 years from the United Kingdom in over 1700 knees from 34 centers and 116 surgeons, there was no difference in the Oxford Score, SF-12, EQ-5D, or need for further surgery or complications. The authors concluded, “We see no difference in any score, if there is a difference, it is too small to be of any clinical significance”. In a prospective of randomised clinical trial performed at Tulane University over 20 years ago, no differences were observed in knee score, a functional patella questionnaire, or the incidence of anterior knee pain between resurfaced and un-resurfaced patellae at time intervals of 2–4 years, 5–7 years, or greater than 10 years. Beyond 10 years the knee scores of total knee patients with a resurfaced patella had declined significantly greater than those with a non-resurfaced patella. There are numerous advantages of not resurfacing the patella including less surgical time, less expense, a lower risk of “major” complications (especially late complications), and if symptoms develop in an un-resurfaced patella, it is an easier salvage situation with more options available. A small percentage of total knee patients will be symptomatic whether or not their patella is resurfaced. Not resurfacing the patella retains more options and has fewer complications. The major determinant of clinical result and the presence of anterior knee pain after knee replacement is surgical technique and component design not whether or not the patella is resurfaced. Patella resurfacing is occasionally necessary for patients with inflammatory arthritis, a deformed or maltracking patella, or symptoms and pathology that are virtually restricted to the patellofemoral joint. For the vast majority of patients, however, patella resurfacing is not necessary

Resurfacing the patella is performed the majority of the time in the US and in many regions it is considered standard practice. In many countries, however, the patella is left unresurfaced an equal amount of the time or even rarely ever resurfaced. Patella resurfacing is not a simple or benign procedure. There are numerous negative sequelae of resurfacing including loosening, fragmentation, avascular necrosis, lateral facet pain, stress fracture, acute fracture, late fracture, and restricted motion. In a study by Berend, Ritter, et al, failures of the patella component were reported 4.2% of the time at an average of only 2.6 years. A study was undertaken at Washington University in recent years to determine whether more clinical problems were observed following total knee replacement with or without patella resurfacing. Records were maintained on all problem total knees cases with well localised anterior knee pain. The referral area for this clinic is St. Louis which is among the largest American cities, with the highest percentage of total knees that are performed without patella resurfacing. During 4 years of referrals of total knee patients with anterior knee pain, 47 cases were identified of which 36 had a resurfaced patella and 11 had a non-resurfaced patella. Eight of 36 resurfaced patellae underwent surgery while only 2 of 11 non-resurfaced patellae underwent subsequent surgery. More than 3 times as many painful total knees that were referred for evaluation had already had their patella resurfaced. In spite of the fact that approximately equal number of total knees were performed in this area without patella resurfacing, far more patients presented to clinic with painful total knee in which the patella had been resurfaced. The numerous pathologies requiring a treatment following patella resurfacing included patella loosening, fragmentation of the patella, avascular necrosis patella, late stress fracture, lateral facet pain, oblique resurfacing, and too thick of a patellar composite. In a large multi-center randomised clinical trial at 5 years from the United Kingdom in over 1700 knees from 34 centers and 116 surgeons, there was no difference in the Oxford Score, SF-12, EQ-5D, or need for further surgery or complications. The authors concluded, “We see no difference in any score, if there is a difference, it is too small to be of any clinical significance”. In a prospective randomised clinical trial performed at Tulane University over 20 years ago, no differences were observed in knee score, a functional patella questionnaire, or the incidence of anterior knee pain between resurfaced and unresurfaced patellae at time intervals of 2–4 years, 5–7 years, or greater than 10 years. Beyond 10 years the knee scores of total knee patients with a resurfaced patella had declined significantly greater than those with a non-resurfaced patella. There are numerous advantages of not resurfacing the patella including less surgical time, less expense, a lower risk of “major” complications (especially late complications), and if symptoms develop in an unresurfaced patella, it is an easier salvage situation with more options available. A small percentage of total knee patients will be symptomatic whether or not their patella is resurfaced. Not resurfacing the patella retains more options and has fewer complications. The major determinant of clinical result and the presence of anterior knee pain after knee replacement is surgical technique and component design not whether or not the patella is resurfaced. Patella resurfacing is occasionally necessary for patients with inflammatory arthritis, a deformed or maltracking patella, or symptoms and pathology that are virtually restricted to the patellofemoral joint. For the vast majority of patients, however, patella resurfacing is not necessary

Hip resurfacing arthroplasty (HRA) is a bone conserving alternative to total hip arthroplasty. We present the early 1 and 2-year clinical and radiographical follow-up of a novel ceramic-on-ceramic (CoC) HRA in a multi-centric Australian cohort.

Patient undergoing HRA between September 2018 and April 2021 were prospectively included. Patient-reported outcome measures (PROMS) in the form of the Forgotten Joint Score (FJS), HOOS Jr, WOMAC, Oxford Hip Score (OHS) and UCLA Activity Score were collected preoperatively and at 1- and 2-years post-operation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis/loosening and heterotopic ossification formation.

209 patients were identified of which 106 reached 2-year follow-up. Of these, 187 completed PROMS at 1 year and 90 at 2 years. There was significant improvement in HOOS (p< 0.001) and OHS (p< 0.001) between the pre-operative, 1-year and 2-years outcomes. Patients also reported improved pain (p<0.001), function (p<0.001) and reduced stiffness (p<0.001) as measured by the WOMAC score. Patients had improved activity scores on the UCLA Active Score (p<0.001) with 53% reporting return to impact activity at 2 years. FJS at 1 and 2-years were not significantly different (p=0.38). There was no migration, osteolysis or loosening of any of the implants. The mean acetabular cup inclination angle was 41.3° and the femoral component shaft angle was 137°. No fractures were reported over the 2-year follow-up with only 1 patient reporting a sciatic nerve palsy.

There was early return to impact activities in more than half our patients at 2 years with no early clinical or radiological complications related to the implant. Longer term follow-up with increased patient numbers are required to restore surgeon confidence in HRA and expand the use of this novel product.

In conclusion, CoC resurfacing at 2-years post-operation demonstrate promising results with satisfactory outcomes in all recorded PROMS.