There is a lack of evidence surrounding selective patella resurfacing, but patella cartilage loss at time of total knee arthroplasty (TKA) is often used as an indication in those who perform it. This study compares the outcomes of TKA without patella resurfacing in patients with and without patella cartilage loss (PFOA). Prospective case control study of 209 consecutive patients undergoing cruciate retaining single radius TKA without patella resurfacing for KL≥3 osteoarthritis. The presence and location of full thickness patella cartilage loss was documented intra-operatively at TKA, identifying n=108 cases with PFOA (mean age 70±9.7, mean BMI 31±6.2, 72 (67%) female) Vs n=101 controls without PFOA (age 68±9.2, BMI31±5.6, 52 (51%) female). Primary outcome measure was improvement in the Oxford Knee Score (OKS) at one year. There were more females in the PFOA group (67% Vs 51%, p=0.037), but no other preoperative differences. There was no difference in preoperative OKS between patients with patella cartilage loss (20.6±7.9) and those without (21.0±7.2, p=0.720). There was no difference in OKS improvement following TKA without patella resurfacing between those with full thickness patella cartilage loss (14.2±9.8) and those without (15.4±9.5, p=0.365). Facet involvement (number and location) did not affect OKSs. No differences were found in the individual OKS questions between groups (p>0.05). There was no difference in one-year OKS or improvements therein between patients with and without full thickness patella cartilage loss treated with single radius cruciate retaining TKA without patella resurfacing, questioning its use an indication for selective patella resurfacing

Anterior knee pain (AKP) is the commonest complication of total knee arthroplasty (TKA). This study aims to assess whether sagittal femoral component position is an independent predictor of AKP after cruciate retaining single radius TKA without primary patellofemoral resurfacing. From a prospective cohort of 297 consecutive TKAs, 73 (25%) patients reported AKP and 89 (30%) reported no pain at 10 years. Patients were assessed pre-operatively and at 1, 5 and 10 years using the short form 12 and Oxford Knee Score (OKS). Variables assessed included demographic data, indication, reoperation, patella resurfacing, and radiographic criteria. Patients with AKP (mean age 67.0 (38–82), 48 (66%) female) had mean Visual Analogue Scale (VAS) Pain scores of 34.3 (range 5–100). VAS scores were 0 in patients with no pain (mean age 66.5 (41–82), 60 (67%) female). Femoral component flexion (FCF), anterior femoral offset ratio, and medial proximal tibial angle all differed significantly between patients with AKP and no pain (p<0.001), p=0.007, p=0.009, respectively). All PROMs were worse in the AKP group at 10 years (p<0.05). OKSs were worse from 1 year (p<0.05). Multivariate analysis confirmed FCF and Insall ratio <0.8 as independent predictors of AKP (R. 2. = 0.263). Extension of ≥0.5° predicted AKP with 87% sensitivity. AKP affects 25% of patients following single radius cruciate retaining TKA, resulting in inferior patient-reported outcome measures at 10 years. Sagittal plane positioning and alignment of the femoral component are important determinants of long-term AKP with femoral component extension being a major risk factor

Aims

The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).

Introduction. Metal on metal hip resurfacing (MMHR) has been advocated for the younger patient for several reasons including for the preservation of bone stock and ease of revision to total hip replacement (THR), thus ‘buying an additional operation’ for the patient. This rationale however assumes a good functional outcome after the revision to a THR and that the results of the ‘revision primary’ will not be compromised by the resurfacing which preceded it. We present our data on a consecutive series of 68 revised MMHRs. Methods. Between September 1997 and September 2009, 927 consecutive patients underwent a hip resurfacing procedure performed by one of three senior surgeons at our institution. The Cormet resurfacing system was used for all patients. Sixty-eight of these patients had their resurfacing revised. Oxford hip score (OHS) obtained at a minimum of 12 months follow-up was used as the primary outcome measure. Results. Average age at time of index procedure was 51.9 (24 to 68) years. The MMHRs were revised an average of 49 (1 to 121) months after index procedure. At time of writing OHS post revision was 21.4 (range 12 to 48) at an average of 42 months post revision (range 16 to 111 months). Patients with a primary diagnosis of dysplasia were at an increased risk of revision RR 3.7 (1.9–7.1, p < 0.05).). No other primary diagnosis significantly increased risk of revision. Five patients underwent a second revision procedure. Discussion. We present the fuctional outcome scores of a large series of revised MMHRs. Despite MMHRs offering the advantage of preservation of bone stock we have found revision of MMHRs to THRs technically difficult. Our functional outcome scores in patients post revision were disappointing. We cannot support the concept that MMHR “buys patients another operation”

The primary aim of this study was to compare the knee specific functional outcome of partial compared with total knee replacement (TKR) for the management of patellofemoral osteoarthritis. Fifty-four consecutive Avon patellofemoral replacements were identified and propensity score matched to a group of 54 patients undergoing a TKR with patella resurfacing for patellofemoral osteoarthritis. The Oxford knee score (OKS), the Short Form (SF-) 12 and patient satisfaction were collected (mean follow up 9.2 years). Survival was defined by revision or intention to revise. There was no significant difference in the OKS (p>0.60) or SF-12 (p>0.28) between the groups. The TKR group was significantly less likely to be satisfied with their knee (95.1% versus 78.3%, OR 0.18, p=0.03). Length of stay was significantly (p=0.008) shorter for the Avon group (difference 1.8 days, 95% CI 0.4 to 3.2). The 10 year survival for the Avon group was 92.3% (95% CI 87.1 to 97.5) and for the TKR group was 100% (95% CI 93.8 to 100). There was no statistical difference in the survival rate (Log Rank p=0.10). The Avon patellofemoral replacement have a shorter length of stay with a functional outcome and satisfaction rate that is equal to that of TKR. The benefits of the Avon need to be balanced against the increased rate of revision when compared with TKR

MHRA guidance for patients with metal on metal hip replacements (MOM) was provided in 2012 and updated in 2017 to assist in the early detection of soft tissue reactions due to metal wear debris. A large number of metal on metal hip replacements were undertaken at our trust. A program of recall for all patients with metal on metal hip replacements was undertaken and MHRA guidelines implemented. Identification and recall of all patients from 2001 with MOM hip replacements using theatre logs, patient records and consultant log books. Two consultant review of X-rays and patient records. Postal questionnaires and GP requests for cobalt & chromium blood tests. Two consultant led MOM review clinics undertaken with metal artefact reduction scans (MARS) performed following consultation in 2017. 674 patients, 297 available for review. 59 refused follow up. 87 moved out of area, 36 untraceable, 26 not MOM, 147 RIP, 22 already revised. From 297 patients 126 female, 171 male, age range 39 – 95 yrs. 126 resurfacing, 171 MOM THR. 26 patients with elevated metal ions, MARS performed of which 17 positive, 9 negative. Of 17 positive scans 10 patients asymptomatic, 7 waiting revision. A time consuming effort and additional resource was needed and supported by the trust. From 297 hips 17 positive MARs were identified (5.7%). A new database registry has been developed to track MOM patients, clinics set up for ongoing follow up with radiological protocols for imaging. An arthroplasty advanced nurse practitioner (ANP) is now trained reviewing patients independently

Objective. To compare regional body composition, bone mineral density (BMD), and clinical outcome in patients with two different shoulder arthroplasty designs. Materials and Methods. This cross-sectional study included 54 patients with a total of 63 shoulder arthroplasties. There were 18 men and 45 women with a mean age of 68.9 years SD ± 10.5. Mean follow-up time was 39.2 months SD ± 14.4. The patients were divided into three groups according to their history: 22 patients were diagnosed with a proximal humeral fracture and treated with a stemmed hemi arthroplasty, 11 patients were diagnosed with osteoarthritis and treated with a stemmed hemi arthroplasty, and 30 patients were diagnosed with osteoarthritis and treated with a resurfacing arthroplasty. All patients underwent a one-day protocol: Regional Dual X-ray Absorptiometri (DXA) was used to measure BMD of the distal third of humerus and regional body composition of the upper arm. The clinical outcome was measured using Western Ontario Osteoarthritis of the Shoulder index (WOOS) and Constant-Murley score. Results. All three groups were comparable regarding demographic data. Mean BMD of the distal third of humerus was 1.029 g/cm2 SD ± 0.204, mean tissue mass of the upper arm was 2.6 kg SD ± 0.7 and mean muscle mass was 1.4 kg SD ± 0.6. BMD of the distal third of humerus, tissue mass and muscle mass were significantly higher in the group diagnosed with osteoarthritis and treated with a resurfacing arthroplasty compared to the group diagnosed with a proximal humeral fracture and treated with a stemmed hemi arthroplasty, P = 0.03, P = 0.01 and P = 0.02 respectively. Median Constant score was 45.0, range 6–89, median WOOS 633, range 28–1824, and median strength 7.0 units, range 0–25. There were no significant differences between the three groups. Nevertheless, there was a trend towards a higher Constant-Murley score and muscle strength in the group of patients diagnosed with osteoarthritis and treated with a resurfacing arthroplasty compared to the group of patients diagnosed with a proximal humeral fracture and treated with a stemmed hemi arthroplasty. Conclusion. After shoulder arthroplasty BMD of the distal third of humerus and body composition are apparently more dependent on diagnosis rather than arthroplasty design. However, a larger number of patients diagnosed with osteoarthritis and treated with a stemmed hemi arthroplasty are needed to support this

Introduction. Controversy exists as to whether the short external rotator tendons and capsule of the hip should be repaired after posterior approach primary total hip arthroplasty (THA). Recent studies using radiopaque markers have demonstrated that reimplantation of these muscle tendons fail early and may not prevent post operative dislocation. Methods. Using dynamic ultrasound examination we evaluated the patency of repair in 68 tendon groups (piriformis/conjoint tendon and obturator externus). We demonstrate short and medium term success in the reimplantation of these tendons using the double transosseous drill hole technique of reattaching the tendons and capsule to the greater trochanter. We followed up 21 of our total hip replacements and 13 hip resurfacings and undertook a dynamic ultrasound examination of the external rotators by an experienced musculoskeletal radiologist to assess their integrity at a minimum of 60 days and 100 days and an average of 213 days after the operation. Results. There were 34 hips assessed in 33 patients. 21 were total hip replacements and the rest were hip resurfacings. Each patient underwent a standard posterior approach by the senior surgeon. The piriformis and conjoint tendons (Group 1) and the obturator extenus (Group 2) were reattached with modified kessler sutures using a transosseous reimplantation technique. The capsule was reattached with a running suture using the same technique. The total hip replacement group had 16 out of 21 hips (76.2%) where both external rotator groups were intact at follow up, compared with 3 out of 13 hips (23.1%) for the hip resurfacing group (Chi-squared 9.188, p=0.002). Group 1 tendons were intact in 81% of the THR group while only in 53.8% in the rsurfaing group. We compared the hip replacement group with the hip resurfacing group using survival analysis techniques (log rank test), which take into account the different follow-up times. The hip replacement group showed a significantly longer time to the event of either rotator group not being intact at follow-up than the hip resurfacing group (log rank 5.568, p=0.018). Conclusions. Our results do appear to suggest that this technique may be of benefit in patients undergoing primary THA but may not be as successful after resurfacing procedures. We propose that the increased incidence of external rotator detachment seen in the resurfacing group may be due to the increased strain imparted on the tendons due to the greater distance to travel, as they wind around the large resurfaced femoral head and neck as compared to the relatively thinner THA femoral neck and smaller head component

INTRODUCTION. Studies have suggested that there is a reduction in head-neck-ratio (HNR) associated with MoMHRA. A reduction in HNR at operation would decrease range of movement and increase impingement risk. Impingement could lead to 20 edge loading, increasing wear. Serum ion levels of Chromium (Cr) and Cobalt (Co) are surrogate markers of wear. Although acetabular component orientation has been shown to contribute to wear and PT development, the role of a decrease in HNR has only been highlighted in PT development. This study aimed to measure changes in HNR that occur at resurfacing and determine any gender- and component size-specific differences. In addition it aimed to determine whether changes in HNR could be associated with increased wear. METHODS. 84 patients (56M: 28F) with unilateral MoMHRA were included. The mean age at surgery was 57 years. The mean femoral component was 49mm. Components were considered small if <45mm, average if between 45–50mm and large if >50mm. Three designs were implanted; BHR, C+ and Recap. The average follow up was 4 years. All patients had Cr/Co levels measured at follow up. Patients were considered to have high ions if Cr and Co levels were 5.1ppb and 4.4ppb respectively. Pre-operative HNR (HNRpre) and the post-operative HNR (HNRpost) were made from the respective pelvic radiographs. Assuming a 2mm thick cartilage layer, the HNR based on the diameter of the articular cartilage pre-operatively (HNRart) was calculated. The immediate changes in HNR as a result of the operation were expressed relative to articular HNR pre-op:. HNRartpost=HNRpost–HNRart. RESULTS. The changes in HNR at operation were significantly negatively correlated with HNRpre, (p<0.001), (rho=−0.77). Females had greater ion levels (p=0.013) and smaller components (p<0.001). Females had bigger pre-operative HNRart and were downsized more (p<0.001). Similarly, patients with small components had higher ions (p=0.032). They had greater HNRart and were downsized more (p<0.001) Twelve patients comprised the high ion group. These patients had smaller components (p=0.004), greater HNRart and were down-sized significantly more at resurfacing (p<0.001). DISCUSSION. This study highlights HNR changes that occur in resurfaced hips. Females, patients with small components and patients in the high ion group had higher pre-operative HNR and were downsized more at operation. Femoral downsize, would probably increase impingement risk, lead to secondary edge loading and contribute to greater incidence of wear related problems

Hip resurfacing arthroplasty is an established and effective intervention for osteoarthritis of the hip in the young active patient, relying on the principle of femoral bone-stock preservation. A recognised mode of failure is neck thinning leading to radiological evidence of neck collapse and clinical failure. We report on a series of these slow-neck-failure patients and highlight the increased incidence of this phenomenon in post-menopausal female patients. This is a single operator, single implant series; 172 cases were identified from databases at our institution. 76 were female, mean (SD) age 52 (7) years. 96 were male, mean (SD) age 51(12) years. 15 (8.7%) patients required revision. 12 (80%) were female, 9 (75%) of these were due to slow neck failure. In the men one patient developed ALVAL requiring removal of his bilateral hip resurfacings, the other failure mode was early femoral neck failure. Mean time to failure was 6 months in men and 37 months in women. This difference in failure rates is also seen in the NJR figures. This review confirms the relatively high incidence of premature failure in post-menopausal females. NICE guidance in 2003, currently under review, stated that resurfacing is indicated in male patients up to 65 and female patients up to 60. As a result of this study we are currently advising post-menopausal patients that this risk of early failure may make total hip replacement a preferable option to resurfacing arthroplasty

Introduction. Although femoral neck fractures remain a concern in short term failures for hip resurfacing, acetabular component position and fixation are increasingly being recognized as causes of mid term failures for hip resurfacing. This study aimed to evaluate the migration pattern of a cobalt chrome, beaded acetabular component for a metal on metal hip resurfacing. Methods. 130 patients underwent metal on metal hip resurfacing: 66 hips in 60 patients had sufficient films to be included in this analysis. Forty-eight patients were male and 12 were female, with a mean age of 50 (range, 32–66). Ninety-five percent of the procedures were performed for osteoarthritis. In all cases acetabular migration was measured both vertically and horizontally, on serial radiographs using the computer-assisted Ein Bild Röntgen Analyse method. A minimum of three comparable radiographs is necessary for calculating the migration curves. We scored medial migration as negative horizontal movement. Results. At a mean follow up 25.3 months (24–36 months), each hip had an average of 5.1 radiographs for analysis. 12.5% of the cups showed more than 1 mm migration in the medial-lateral axis and 45.3% more than 1 mm in the vertical axis. 23% of the cups showed a combined migration of greater than 2 mm in the observation period. Two of these cases required revision for aseptic loosening at 34 months. Discussion and Conclusion. Previous studies have shown EBRA to have an excellent sensitivity and positive predictive value for mid to long term cup failure. This data raises concern about the initial stability if this acetabular component. Continued follow-up is needed to monitor the longer term survival of this implant

Background. Hip resurfacing arthroplasty (HRA) has seen a recent revival with third generation Metal-on-Metal prostheses and is now widely in use. However, safety and effectiveness of hip resurfacing are still questioned. We systematically reviewed peer-reviewed literature on hip resurfacing arthroplasty to address these issues. Objective. To evaluate implant survival and functional outcomes of hybrid Metal-on-Metal hip resurfacing arthroplasty (HRA). Method. Electronic databases and reference lists were searched from 1988 to May 2010. Identified abstracts were checked for inclusion or exclusion by two independent reviewers. Data were extracted and summarized by one reviewer and verified by a second reviewer. Main study endpoint was implant survival, which we compared with the National Institute of Clinical Excellence (NICE) benchmark. We also evaluated radiological and functional outcomes, failure modes and other adverse events. The quality of evidence was judged using the Grading of Recommendations Assessment, Development and Evaluation system (GRADE). Results. We identified 539 articles, of which 29 met the inclusion criteria. The studies included one randomised clinical trial, 27 prospective case series and one retrospective case series. Data were extracted from these 29 articles, totalling 10621 resurfaced hips, providing details on five out of 11 resurfacing devices on the market. Mean follow up ranged from 0.6 to 10.5 years and implant survival ranged from 84% to 100%. Of the 10621 hips, 370 were revised (3.5%), with aseptic loosening as most frequent failure mode. None of the HRA implants used to date met the full 10 year NICE benchmark. Thirteen studies showed satisfactory implant survival percentages compared to the three year NICE entry-benchmark. These 13 studies used the BHR implant (eight studies), the Conserve plus (two studies), the Durom implant (one study), the Cormet 2000 implant (one study) or both the McMinn and the BHR implant (one study)

Background. Metal on metal hip resurfacing has become popular worldwide for younger patients because of perceived advantages in function and ease of revision, due to bone conservation. Joint Registry data have shown increased risk of early failure, particularly in younger females. There have been few studies comparing the outcome of resurfacing to cemented total hip arthroplasty (THA). Methods. 715 Hip Resurfacings (HR) performed between 2000 and 2010 with up to 10 years follow-up were compared with 2210 Exeter cemented Total Hip Arthroplasties (THA) performed for all diagnoses during the same period within our region. Survivorship was recorded using revision for any cause as the end point. Harris Hip Scores were collected pre-operatively and at 1,3,5 and 7 year review. Prospective independent analysis was carried out using Kaplan Meier survivorship, and non-parametric testing to investigate the effect of age (under 55 and over 55) and gender on revision rate and Harris Hip Score. Results. Over the 10 year period survival of Exeter THA was better than HR overall. Revision rate 2% for THA and 7% for HR; P < 0.0001. There was no significant difference in risk of revision between THA and HR in males at any age. In females there was a significantly increased revision rate with HR. Under 55 Revision rates: THA 0%; HR 6.7%. 55 & over Revision rates: THA 1.3%, HR 5.9%, P < 0.0001. Harris Hip Scores were significantly better overall in the HR group. Sub-group analysis showed that Harris Hip Scores were not significantly different for males under 55. In all other groups (males over 55 and females under and over 55) Harris Hip Scores were better after HR compared with THA. Conclusions. In this series survivorship and functional scores for HR are at least as good as for THA in males. The increased risk of revision after HR in females should be weighed against advantages of bone conservation and better post-op hip scores

Introduction. New methods to reduce inpatient stay, post-operative complications and recovery time are continually being sought in surgery. Many factors affect length of hospital stay, such as, analgesia, patient and surgeon expectations, as well as provision of nursing care and physiotherapy. Development of the use of postoperative local anaesthetic infiltration delivered intra-articularly by a catheter appears to be an effective analgesic method which reduces patient's opioid requirements and allows early physiotherapy without motor blockade of muscles. Our study aimed to explore if the use of local anaesthetic infiltration intra-articularly following joint athroplasty affected the patient's duration of hospitalisation. Methods. Looking retrospectively at arthroplasty audit data, we compared two groups of age and sex-matched patients who underwent primary hip arthroplasty (replacement and resurfacing) and knee arthroplasty performed by a single surgeon using the same surgical techniques. The surgeon began to utilize local anesthetic infiltration intra-articularly in 2009. The first group included patients operated on the year prior to the change and the second group were those operated on within a year of the change of practice. There were 103 patients (27 resurfacings, 28 knees, 48 hips) in the local anaesthetic group and 141 patients (48 resurfacings, 36 knees, 64 hips) in the non-local anaesthetic group. The length of stay was investigated for plausible Normality using the Shapiro Wilks statistic. Between-treatment group differences were examined using one-way analysis of variance (ANOVA). Factors observed were, use of local anaesthetic (yes/no), joint (hip/knee) and day of surgery (weekend/not weekend). Between treatment group differences in gender and complications were investigated using Chi-squared methods. Results. Patients who received local anaesthetic had shorter stays, irrespective of the joint or day of operation. Patients undergoing hip arthroplasty discharged sooner when local anaesthetic was used compared with those without (mean 4.0 days and 4.4 days respectively P=0.04). Patients undergoing knee replacement also discharged sooner when local anaesthetic was used compared with those without (mean 4.9 days and 6.1 days respectively P=0.09). When knee and hip figures were combined and analysed to measure the significance of effects of treatment on the length of stay, local anaesthetic use was found to be statistically significant in reducing length of stay (P=0.01). There were no between-treatment group differences in proportions of complications, gender or day of surgery. Conclusion. The findings of this study highlight that local anaesthetic infiltration reduces duration of in-patient stay following knee and hip joint athroplasty and there is no associated significant increase in immediate post-operative complications

The use of Birmingham hip resurfacing (BHR) remains controversial due to the increased revision rate in female patients. We compared the outcomes of BHR in female patients to an age matched total hip arthroplasty(THA) cohort. We reviewed the pain, function and total Harris Hip Scores(HHS), and Kaplan-Meir survivorship for BHR and THA cohorts from a prospective regional arthroplasty database. There were 234 patients in each cohort, with mean age of 51 years. The BHR cohort had significantly better function and total HHS at all points of the 5-year study, but not for the post-operative pain score. The 5-year revision rate for the BHR cohort was significantly higher than the THA cohort (6.8% vs 3.4%, p=0.001). The main reason for revision in the BHR cohort was aseptic loosening (n=8), followed by metallosis (n=3). The 5-year Kaplan-Meier survivorship was 92.6% (95% CI±1.7%) and 96.4% (95% CI±1.3%) for the BHR and THA cohort (p=0.001). BHR can give significantly better functional outcomes than THA. The vast majority of female patients were happy with BHR and did not need further surgery at the 5-year stage. This is somewhat at odds with the recent reputation of the procedure. The 10-year result of the same cohort is warranted to provide further data. Our study is not a recommendation to still offer BHR to female patients, but rather to inject a note of realism into the debate. There are implications for future implant development in that these results do validate resurfacing as a functionally valuable option for active patients

INTRODUCTION. Femoral neck narrowing (NN) following Metal-on-Metal Hip Resurfacing Arthroplasty (MoMHRA) is a well-recognised clinical phenomenon. The incidence of resurfaced hips with NN > 10% is reported to be up to 27%. Its pathogenesis is thought to be multi-factorial secondary to stress shielding, impingement, osteolysis secondary to wear/ion particles and as a result of reduced vascularity and pressure effect on cancellous bone secondary to the presence of a soft-tissue mass around the resurfaced hip. Recognised risk factors for its development include: female gender and the presence of a pseudotumour. Serum Chromium (Cr) and Cobalt (Co) are recognised surrogate markers of in-vivo wear of MoMHRA. The aims of this study were to establish whether NN is associated with increased wear. METHODS. A cohort of 214 patients with unilateral MoMHRA (139M: 75F) was included in this study. Primary osteoarthritis was the diagnosis leading to surgery for the majority of patients (208). The average age at surgery was 54.1 years old (13–73). Six different implants were used; BHR (116), Conserve plus (92), Recap (2), ASR (2), Adept (1) and Cormet (1). The average femoral component size was 49.2mm (range: 38–59). The average follow up was 4.3 years (range: 2–10). Patients were subdivided into 3 groups as per implant size. Small size component group had implants <45mm, average size group had components 45–51mm and large component size group had components >51mm. All patients had Prosthesis-Junction-Ratio (PJR) measured from postoperative (PJRpost) and at latest follow up (PJRfollow) radiographs. Measurements were made using the method described by Lilikakis1. Metal ion levels (Cr/Co) were measured at last follow-up for all patients. Cr level >5.1g/ml and Co levels >4.4 g/ml were considered high2 and patients with such levels formed the high ion group. RESULTS. For the whole cohort, mean NN was 3.2% (range: 0–32%, SD:4.3). Females (4.7%, range: 0–32%, SD: 5.8) had significantly greater NN than males (2.4%, range: 0–23%, SD: 2.9) (p=0.001). Patients in the large component group had less NN (2.1%, SD: 2.3) in comparison to the average (3.2%, SD: 3.7%) (p=0.046) and the small (5.9%, SD: 7.9) (p=0.007) component size groups. There was no difference in NN between small and average sized components (p=0.1). Patients in the high ion group (25 patients) had significantly greater NN than patients with low ions (10.1%, range: 1%–32%, SD: 8.3 Vs 2.3%, range: 0–11, SD 2.3) (p<0.0001). NN >10% was seen in 16 hips (7.5%). The odds ratio of having high ions if NN >10% was 125 (p<0.001). DISCUSSION. The findings of this study showed that greater NN occurs in females and patients with small components and in patients with high ions. Furthermore, hips with NN >10% should be investigated further as they are more likely to have increased wear

Introduction. Patellar tracking in total knee replacements has been extensively studied, but little is known about patellar tracking in isolated patellofemoral replacements. We compared patellar tracking and the position of the patellar groove in the natural knee, followed by implantation of the femoral component of a PFR (patella unresurfaced) and after implantation of the femoral & patellar component of the PFR. Methods. Computer navigation was used to track the patella in eight whole lower extremities of four cadavers in the natural knee, in the same knee with the femoral component of the PFR (PFR-P) and with the femoral and patellar component of the PFR (PFR+P, patella resurfaced) (Depuy Sigma PFR). The form and position of the trochlea in the natural knee and the patellar groove of the femoral component was also analysed. Values are means+/−SD, two tailed Student's t-test for paired samples. Results. With a PFR-P the patella had a slightly more lateral tilt (0.8+/−0.8° to 2.8+/−2.5° at 40–100° of flexion, p<0.05 vs. Nat), this was more pronounced with the PFR+P (2.0+/−0.7° to 4.9+/−1.8° at 20–90° flexion, p<0.05 vs. Nat., p<0.05 vs. PFR-P at 20–80° flexion). No differences in patella rotation were seen between the three groups. In the PFR-P group the patella tracked a little more medially compared to the natural knee (0.6+/− 0.7mm to 1.3+/−2.6mm, p<0.05 at 20°,80°,90° flexion). The difference was more pronounced after patella resurfacing (PFR+P) (2.1+/−2.0mm to 3.0+/−2.2mm, p<0.05 vs. Nat. at 10°–100°, p<0.05 vs. PFR-P from 10–100°). When analysed relative to the patellar groove of the trochlea/femoral component the patella in the natural knee tracked slightly lateral to the groove (2.0+/−1.7mm to 2.9+/−2.0mm at 50–100° p<0.05), so did the patella of PFR-P (2.0+/−2.3mm to 2.3+/−2.3mm at 60–90° flexion, p<0.05), whilst the PFR+P tracked right on the groove (0.6+/−3.7mm medially to 0.6+/−2.9mm laterally, p<0.05 vs Nat at 10–30° & 70–100°, p<0.05 vs. PFR-P at 10–100°). Distance from the patellatot the epicondylar axis was slightly larger in the PFR-P group (0.6+/− 0.7mm to 1.3+/−1.4mm, p<0.05 vs. Natu at 20,80 & 90°. This was more pronounced with patellar resurfacing (2.1+/−2.0 to 3.0+/−2.2mm, p<0.05 vs. Nat at 10–100°, p<0.05 vs. PFR-P at 20–100°) The patella groove on the natural knee and the implanted femoral component of the implanted PFR had the same radius, inclination relative to the femoral mechanical axis, antero-posterior position and medio-lateral orientation. As intended by the designers the groove of the patellar component extended about 13mm further superiorly and 0.5mm more inferiorly. Discussion. The patella groove on the femoral component of the PFR reproduces the natural trochlear anatomy well. Patella tracking in the PFR-P shows only minor differences compared to the natural knee. Resurfacing of the patella in the PFR+P group causes the patella to tilt a little more laterally and track a little more medially, the distance to the epicondylar axis is slightly larger but this allows the patella to engage better in the patellar groove of the femoral component

The Global Conservative Anatomic Prosthesis (Global CAP) is an uncemented press fit humeral resurfacing implant developed by DePuy. We report a single surgeon series of Global CAP prostheses implanted in Norwich. 103 procedures were carried out between 2006 and 2011, in 93 patients. Mean age was 72 years (range 43 to 90). Patients were followed up for a mean 8 months (range 0 to 56). Pre-operative Oxford shoulder scores were recorded in a preadmission clinic and an Oxford score questionnaire was sent to patients post-operatively in December 2011. The mean score preoperatively was 19, rising to 28 postoperatively. Two patients developed rotator cuff tears and have been revised to reverse polarity arthroplasty. One is pending revision for a cuff tear. This prosthesis shows promise at this early stage for compensated glenohumeral arthritis when a bone preserving procedure is desirable

Introduction. Since the introduction of 3rd generation Metal-on-Metal-Hip-Resurfacing-Arthroplasty (MoMHRA), thousands of such prostheses have been implanted worldwide in younger patients with end-stage hip osteoarthritis. However, no independent centre has reported their medium-to-long term outcome. The aim of this study is to report the ten year survival and outcome of the Birmingham Hip Resurfacing (BHR), the most commonly used MoMHRA worldwide. Methods. Since 1999, 648 BHRs were implanted in 555 patients, the majority of which were male (326). The mean age at surgery was 52.1years (range: 17–82), with primary OA as most common indication (85%). Mean follow up was 7.1years (range: 1–11). The Oxford Hip Score (OHS) and UCLA questionnaires were sent to all patients. Implant survival was established, with revision as the end point. Sub-analysis was performed by gender, femoral component size (small: <45mm, standard: 46–52, large: >53mm) and age at surgery (young:<50yrs, old:>50yrs). Results. Preliminary results show that survival and clinical outcome were better in men than women (p=0.013) and in patients with large and standard components compared to small (p=0.005). In women the survival and clinical outcome were worse in the young than the old (p=0.049). In men there was no difference in survival or clinical outcome between the young and old (p=0.106). In young men the 10-year survival was 95%, the mean OHS was 45 and the mean UCLA score was 8.1. Conclusion. The results of resurfacing are good in men. They perform particularly well in the young and highly active men who tend to have problems with conventional hip replacements

Background. Improving positioning and alignment by the use of computer assisted surgery (CAS) might improve longevity and function in total knee replacements. This study evaluates the short term results of computer navigated knee replacements based on data from a national register. Patients and Methods. Primary total knee replacements without patella resurfacing, reported to the Norwegian Arthroplasty Register during the years 2005–2008, were evaluated. The five most common implants and the three most common navigation systems were selected. Cemented, uncemented and hybrid knees were included. With the risk for revision due to any cause as the primary end-point, 1465 computer navigated knee replacements (CAS) were evaluated against 8214 conventionally operated knee replacements (CON). Kaplan-Meier survival analysis and Cox regression analysis with adjustment for age, sex, prosthesis brand, fixation method, previous knee surgery, preoperative diagnosis and ASA category were used. Results. Kaplan-Meier estimated survival at two years was 97.9% (95% CI: 97.5–98.3) in the CON group and 96.4% (95% CI: 95.0–97.8) in the CAS group. The adjusted Cox regression analysis showed a statistically significantly higher risk for revision in the CAS group (relative risk = 1.7, 95% CI: 1.1–2.5, p = 0.019). The LCS complete knees had a significantly higher risk for revision with CAS, compared to CON (relative risk = 2.1 (95% CI 1.3–3.4, p = 0.004)). Mean operating time was 15 minutes longer in the CAS group. Conclusion. Survivorship at two years of computer navigated primary total knee replacements was inferior compared to conventionally operated knees. Therefore, an extensive use of CAS in primary total knee replacement surgery cannot be encouraged until proven superior in long term register studies and clinical trials