Aims. The aim of this study was to investigate the potentially increased risk of dislocation in patients with neurological disease who sustain a femoral neck fracture, as it is unclear whether they should undergo total hip arthroplasty (THA) or hemiarthroplasty (HA). A secondary aim was to investgate whether dual-mobility components confer a reduced risk of dislocation in these patients. Methods. We undertook a longitudinal cohort study linking the Swedish Hip Arthroplasty Register with the National Patient Register, including patients with a neurological disease presenting with a femoral neck fracture and treated with HA, a conventional THA (cTHA) with femoral head size of ≤ 32 mm, or a dual-mobility component THA (DMC-THA) between 2005 and 2014. The dislocation rate at one- and three-year revision, reoperation, and mortality rates were recorded. Cox multivariate regression models were fitted to calculate adjusted hazard ratios (HRs). Results. A total of 9,638 patients with a neurological disease who also underwent unilateral arthroplasty for a femoral neck fracture were included in the study. The one-year dislocation rate was 3.7% after HA, 8.8% after cTHA < 32 mm), 5.9% after cTHA (= 32 mm), and 2.7% after DMC-THA. A higher risk of dislocation was associated with cTHA (< 32 mm) compared with HA (HR 1.90 (95% confidence interval (CI) 1.26 to 2.86); p = 0.002). There was no difference in the risk of dislocation with DMC-THA (HR 0.68 (95% CI 0.26 to 1.84); p = 0.451) or cTHA (= 32 mm) (HR 1.54 (95% CI 0.94 to 2.51); p = 0.083). There were no differences in the rate of reoperation and revision-free survival between the different types of prosthesis and sizes of femoral head. Conclusion. Patients with a neurological disease who sustain a femoral neck fracture have similar rates of dislocation after undergoing HA or DMC-THA. Most patients with a neurological disease are not eligible for THA and should thus undergo HA, whereas those eligible for THA could benefit from a DMC-THA. Cite this article: Bone Joint J 2022;104-B(1):134–141

The primary aim was to assess whether patients waiting 6-months or more for a total hip (THA) or knee (KA) arthroplasty had a deterioration in their health-related quality of life (HRQoL). Secondary aims were to assess change in level of frailty and the number living in a state worse than death (WTD). Eight-six patients waiting for a primary TKA or KA for more than 6-months were selected at random from waiting lists in three centres. Patient demographics, waiting time, EuroQol 5-dimension (EQ-5D) and visual analogue scores (EQ-VAS), Rockwood clinical frailty score (CFS) and SF-36 subjective change in HRQoL were recorded at the time of and for a timepoint 6-months prior to assessment. The study was powered to the EQ-5D (primary measure of HRQoL). There were 40 male and 46 female patients with a mean age of 68 (33 to 91) years; 65 patients were awaiting a THA and 21 a TKA. The mean waiting time was 372 (226 to 749) days. The EQ-5D index deteriorated by 0.222 (95%CI 0.164 to 0.280, p<0.001). The EQ-VAS also deteriorated by 10.8 (95%CI 7.5 to 14.0, p<0.001). CFS progressed from a median of 3 to 4 (p<0.001). The number of patients WTD increased from seven to 22 (p<0.001). Thirty-one(36%) patients felt their HRQoL was much worse and 28 (33%) felt it was somewhat worse. Patients waiting more than 6-months had a clinically significant deterioration in their HRQoL and demonstrated increasing level of frailty with more than a quarter living in a health state WTD

Introduction. Total femur implantation is a rare and challenging procedure in final revision surgery of hip and knee arthroplasties. Reports of this operation technique are even rare in literature. In this study we retrospectively analyse our patients with total femur implants. Material and Methods. Between October 2002 and February 2009 we implanted 27 total femurs in hip and knee revision surgery cases. We used the modular prosthesis system–Megasystem C® by Waldemar Link–in all cases. Our 22 female and 5 male patients had a mean age of 76 years (range 45–88). Indications for the procedure were loosening of megaprosthesis of the hip in 12 cases; 2 with massive distal migration, 1 with penetration into the knee joint and 1 after two step revision procedure. In 13 cases a periprosthetic indicated a total femur implanatation due to massive bone loss; 1 breakage of a long femoral stem, 5 fracture of osteosynthesis materials, 3 after prosthesis revisions and 1 pseudoarhrosis of femur and tibia after knee arthroplasty. We analysed perioperative complications, clinical status and result and further revision within follow up time. Results. We were able to examine 16 patients at follow up time. Eight patients were lost to follow up and 2 have been died; 1 after fulminant pulmonal embolia after operation and 1 four years postoperatively. One total femur had to be exchanged due to infection after 1 year. Perioperative complications occurred as follows: 1 massive blood transfusion, 1 peroneal palsy, 1 ulcus ventriculis bleeding, 1 thrombosis of vena suclavia and vena jugularis, 1 sigmaresection due to diverticulosis, 1 luxations of the hip, and 2 wound necrosis. In 3 caese a revision operation swas performed; 1multiple luxtion of the hip and due to infection of the total femur implant. The range of motion of the hip was 85 degrees (range 30–90) and knee 92 degrees (range 30–110). In nearly all cases we found a lengthening of the revised limb. The general outcome of the patients was. Ten patient were very satisfied, 2 statisfied and 2 fair due to pain persistence. Two patient were mobile with one crutch, 3 used two crutches and one was able to walk with a rollator. One patient was unable to walk due to diplegia after spine fracture. Conclusion. Total femur procedure in final revision arthroplasty has a high potential of perioperative risks but has shown good clinical and mobility results in our patient group. With the Megasystem C® by Link we had a save and good performance while operation of this difficult patient group

Sacral tumours are rare and can present difficult diagnostic and therapeutic challenges even at an early diagnosis. Surgical resection margins have a reported prognostic role in local recurrence and improved survival. Successful management is achieved within a specialist multidisciplinary service and involves combination chemotherapy, radiotherapy and surgery. We present our experience of patients with sacral tumours referred to our unit, who underwent total and subtotal sacrectomy procedures. Materials and Methods. Between 1995 and 2010, we identified twenty-six patients who underwent a total or subtotal sacrectomy operation. Patients were referred from around the United Kingdom to our services. We reviewed all case notes, operative records, radiological investigations and histopathology, resection margins, post operative complications, functional outcomes and we recorded long-term survival outcomes. Patients who were discharged to local services for continued follow up or further oncological treatment were identified and information was obtained from their general practitioner or oncologist. We reviewed the literature available on total sacrectomy case series, functional outcomes and soft tissue reconstruction. Results. We reviewed 26 patients, 16 male and 10 female, with a mean age at presentation of 53.4 years (range 11–80 years). Duration of symptoms ranged from 2 weeks to 6 years; lower back pain and sciatica were amongst the most common presenting features. Histological diagnoses included chordoma, Ewing's, malignant peripheral nerve sheath tumour, chondromyxoid fibroma, spindle cell sarcoma, synovial sarcoma, chondrosarcoma. A combined approach was used in two-thirds of patients and most of these patients had a soft tissue reconstruction with pedicled vertical rectus myocutaneous flap. Complications were categorised into major and minor and subdivided into wound, bladder and bowel symptoms. Wound complications and need for further intervention were more common amongst the patient group who did not have simultaneous soft tissue reconstruction at operation. All patients had a degree of bladder dysfunction in the early postoperative period. We present survivorship curves including recurrence and development of metastases. Conclusion. Total sacrectomy procedures carry a high risk of associated morbidity but can improve survival amongst specific groups of patients. They present challenges in diagnosis and management, but must be referred to a specialist service, that will instigate appropriate investigations and treatment regimes within a multidisciplinary setting. The expansion of services from other specialties required for the postoperative and ongoing rehabilitation plays an important role in overall management and appropriate pathways to coordinate these services are necessary

Aims. Our aim was to analyse the long-term functional outcome of two forms of surgical treatment for active patients aged > 70 years with a displaced intracapsular fracture of the femoral neck. Patients were randomised to be treated with either a hemiarthroplasty or a total hip arthroplasty (THA). The outcome five years post-operatively for this cohort has previously been reported. We present the outcome at 12 years post-operatively. Patients and Methods. Initially 252 patients with a mean age of 81.1 years (70.2 to 95.6) were included, of whom 205 (81%) were women. A total of 137 were treated with a cemented hemiarthroplasty and 115 with a cemented THA. At long-term follow-up we analysed the modified Harris Hip Score (HHS), post-operative complications and intra-operative data of the patients who were still alive. Results . At a mean follow-up of 12 years (8.23 to 16.17, standard deviation 2.24), 50 patients (20%), 32 in the hemiarthroplasty group and 18 in the THA group, were still alive, of which 47 (94%) were women. There were no significant differences in the mean modified HHS (p = 0.85), mortality (p = 0.13), complications (p = 0.93) or rate of revision surgery (p = 1.0) between the two groups. Conclusion. In the treatment of active elderly patients with an intracapsular fracture of the hip there is no difference in the functional outcome between hemiarthroplasty and THA treatments at 12 years post-operatively. Cite this article: Bone Joint J 2017;99-B:250–4

The aim was to perform a cost-utility analysis of total joint replacement in the current environment. Arthritis is a disabling condition that leads to long-term deterioration in quality of life. Total joint replacement, despite being one of the greatest advances in medicine in the modern era, has come under recent scrutiny. The National Health Service (NHS) has competing demands and resource allocation is challenging in times of economic restraint. Patients undergoing total hip (n=348) and knee arthroplasty (n=323), from January to July 2010, were entered into a prospective arthroplasty database. A health utility score was derived from the Euroqol (EQ-5D) score preoperatively, and at one year, and was combined with individual life expectancy to derive the Quality-Adujusted-Life-Years (QALYs) gained. Predicted need for revision surgery was Incorporated in the model. The 2011–12 Scottish Tariff was used. Two-way analysis of variance was used to compare QALYs gained between procedures, while controlling for baseline differences. The number of QALYs gained was higher in THR versus TKR (6.53 vs 4.04 years, p<0.001). The cost per QALY for THR was £1371 (95% CI £1194 to £1614) compared with £2101 (£1762 to £2620) for TKR. Predictors of an increase in QALYs gained were poorer health prior to surgery (p<0.001) and younger age (p<0.001). General health (EQ-5D VAS) showed greater improvement in THR versus TKR (p<0.001). This study provides up to date cost-effectiveness data for total joint replacement. THR and TKR are both extremely clinically and cost-effective interventions, with costs that compare favourably with other medical interventions (e.g. laparoscopic hernia repair vs open: £55,548 per QALY; CHD primary prevention with statins: £21,000)

Introduction. Insufficient arthroscopic cuff tear reconstruction leading to massive osteoarthritis and irreparable rotator cuff tears might be salvaged by implantation of an inverted total shoulder prosthesis Delta in the elderly. However, despite the generally high success rate and satisfying clinical results of inverted total shoulder arthroplasty, this treatment option has potential complications. Therefore, the objective of this study was a prospective evaluation of the clinical and radiological outcome after a minimum of 2 years follow-up of patients undergoing inverted shoulder replacement with or without prior rotator cuff repair. Patients and Methods. Sixty-eight shoulders in 66 patients (36 women and 30 men) operated between February 2002 and June 2007 with a mean age of 66 years (ranging from 53 to 84 years) were first assessed preoperatively and then at minimum 2 years follow-up, using the Constant score for pain, Constant Shoulder Score, Oxford Shoulder Score, UCLA Shoulder rating scale, DASH Score, Rowe Score for Instability and Oxford Instability Score. 29 patients (Group A) had undergone previous shoulder arthroscopy for cuff tear reconstruction at a mean of 29 months (range 12 to 48 months) before surgery and 39 patients (Group B) underwent primary implantation of an inverted total shoulder prosthesis Delta. Any complications in both groups were assessed according to Goslings and Gouma. Results. We report statistically significant improvements of all obtained scores at a mean follow-up of 42 months (ranging from 24 to 96 months) in both groups. Significant outcome differences between 29 patients with previous shoulder arthroscopy for cuff tear reconstruction and 39 without previous shoulder arthroscopy were not observed. Eight complications occurred altogether, in terms of a nerve lesion once, loosening of the humeral stem three times, and loosening or fracture of the glenoid component four times. Conclusion. We did not detect any statistically significant impact of previous insufficient shoulder arthroscopy for cuff tear reconstruction on the outcome and survival rate after the implantation of the inverted total shoulder prosthesis Delta. We conclude that reverse total shoulder arthroplasty with the Delta prosthesis is significantly beneficial in terms of less shoulder pain, higher stability and gain of range of motion without this beneficial effect being significantly weakened by previous insufficient shoulder arthroscopy for cuff tear reconstruction. We believe that previous arthroscopic cuff tear reconstruction should therefore be included in the treatment algorithm

Background. It is unclear which form of anaesthesia is the most favourable in primary total hip replacement (THR) surgery. A recently published systematic review of modern anaesthesia techniques in primary THR surgery (Macfarlane 2009) was not able to show any convincing benefit of regional or general anaesthesia. One retrospective study that examined anaesthesia and leg length (Sathappan 2008), found an increased incidence of leg length difference > 5 mm in those patients who were operated with regional anaesthesia. Our department used a mini invasive approach in supine as standard procedure in THR. The type of anaesthesia that is chosen is up to the individual anaesthetist. Purpose. We wanted to see if there was any correlation between type of anaesthesia and leg length, total time spent in theatre and recovery room, postoperative hospital stay, blood loss or operating time in primary THR surgery with a mini invasive approach in supine. Materials and Methods. Our study was a retrospective study of 170 primary THR patients. All patients received an uncemented Corail stem and a cemented Marathon cup. Patients with abnormal anatomy, BMI > 46, simultaneous removal of internal fixation or incomplete data were excluded in the analysis. Radiograpic leg length was measured using the inter teardrop line and the lesser trochanter. Results. 99 patients were operated on with spinal anaesthesia and 71 with total intravenous anaesthesia (TIVA). There were 65% women in both groups. Average age was 74 years (32–95) in the spinal anaesthesia group and 67 years (38–93) in the TIVA group. We found no significant difference in the average operating time (spinal 65 min, TIVA 64 min), drop in haemoglobin to the first postoperative day (spinal 16%, TIVA 16%), postoperative hospital stay (Spinal 1.4 days, TIVA 1.4) or in transfusion rate (spinal 1%, TIVA 1.4%). We found a significant difference in the proportion of patients with a leg length difference of more than 7 mm (Spinal 22%, TIVA 6%, p = 0.02) and the average total time spent in theatre and post-operative department (spinal 325 min, TIVA 293 min, p < 001). Discussion. The study is retrospective and is therefore fettered by the limitations inherent in such a study. Our study seems to confirm the earlier findings that the type of anaesthesia can affect leg length in primary THR. It is speculated that spinal anaesthesia has a more unpredictable effect on muscular tension which could explain this

Successful return to work (RTW) is a crucial outcome after primary total knee arthroplasty (TKA) in patients under 65 years old. We aimed to determine whether TKA facilitated RTW in patients <65 years, whose intention was to return preoperatively.

We prospectively assessed 106 TKA patients under 65 years over a 1 year period both preoperatively and at 1 year following surgery. Patient demographics were collected including Oxford knee score, Oxford-APQ, VAS pain/health scores and EQ-5D. A novel questionnaire was distributed to delineate pre-operative employment status and post-operative intentions. This included questions on nature of pre and post-operative occupation, whether joint disease affected their ability to work and details of retirement plans and how this was affected by their knee.

69 patients intended to return to work following their TKA. Following arthroplasty, 57/69 patients (82.6%) returned to work at a mean of 16.4 weeks (SD 16.6). Univariate analysis showed significant factors facilitating RTW included, pre-operative oxford knee score, pre-operative Oxford-APQ score and pre-operative EQ-5D score. These were not predictive on multivariate analysis.

This study finds that TKA facilitates return to work in 83% of those who intend to return to work following their surgery. This could have significant positive and health and financial cost implications for the individual, health system and society.

Many psychological factors have been associated with function after joint replacement. Personality is a stable pattern of responses to external conditions and stimuli. The aim of this study was to investigate the relationship between personality, joint function, and general physical in patients undergoing total hip (THR) and knee replacement (TKR). We undertook a prospective cohort study of 184 patients undergoing THA and 205 undergoing TKA. Personality was assesed using the Eysneck Personality Questionaire, brief version (EPQ-BV). Physical health was measured using the EuroQol (EQ-5D). Joint function was measured using the relevant Oxford Score. Outcomes were assessed at six months. Multivariable models were constructed. The stable introvert personality was most common. Unstable introverts had poorer pre-operative function with hip arthrosis, but not knee arthrosis. Personality was not directly associated with post-operative function – the only independent predictors were pre-operative function (p=0.002) and comorbidity (p<0.001). While satisfaction after TKR was associated with personality (p=0.026), there was no association after THR (p=0.453). The poorest satisfaction was in those with the unstable introvert personality type. Personality was a predictor of preoperative status. It did not have a direct association with postoperative status, but may have as preoperative function was the main predictor of postoperative function, personality may have had an indirect effect. Personality was also a predictor of satisfaction after TKR. This suggests that predicting satisfaction after knee replacement is more complex. Therefore certain patient may benefit from a tailored preoperative education to explore and manage expectations

Reduced length of stay (LOS) is logistically, economically and physiologically beneficial. Although a high proportion of total joint arthroplasty (TJA) patients are suitable for same day admission (SDA), removable barriers persist in many centres. This study aimed to determine factors limiting SDA and quantify the impact of implementing both SDA and a targeted enhanced recovery programme on length of stay.

This single-centre retrospective cohort study collected data on elective TJA patients aged <60. Qualitative service reviews identified opportunities for optimisation. Improvements were implemented in 2017, including: obtaining consent at the pre-assessment clinic and robustly assessing suitability for SDA. A targeted rapid recovery program was implemented in June 2018. Data was collected prior to changes in 2017, and following changes in 2018.

106 of 108 screened patients were eligible for inclusion. There were no significant between-year differences in baseline health characteristics. Significantly greater proportions of 2018 patients were consented at their pre-assessment clinic (56% vs 8.9%, p<0.001) and assessed as suitable for SDA (94% vs 57.1%, p<0.001). Pre-operative LOS was significantly reduced in 2018 for both total hip replacements (median [IQR]: 0[0,0] vs 1[1,1], p<0.001) and total knee replacements (median [IQR]: 0[0,0] vs 0[0,1], p=0.002). The departmental mean LOS improved from 4.7 days to 3.7 days following SDA. This was further shortened to 3.2 days after introduction of the rapid recovery program.

When a larger proportion of patients were deemed suitable for SDA, this correlated with reduction of LOS. The department now performs above national standards in both of these parameters.

In this review, we present the data of one of the largest non-designer, mid- to long-term follow ups of the AGC. We present a total of 1538 AGC knees during a 15 year period, of which 902 were followed up by postal or telephone questionnaire focused on Oxford Knee Scores, Visual analogues of function and pain and survival analyses performed. Mean length of follow up was 10.4 years. 85.7% of patients had an Oxford knee score of between 0 and 40, with 71.2% scoring between 0–30. 65.6% of patients responded with a Visual Analogue Score (VAS) of 0 or 1 at rest (minimum pain 0) and 53.9% reporting VA scores of 0 or 1 while walking. 87.5% of patients reported Excellent or good functional reports at final follow up and 90.3% reporting excellent or good pain control compared to per-operative levels. Survival analysis confirms excellent survivorship. This large cohort and multi-surgeon trial reproduces the excellent results as demonstrated by the designer centre (Ritter et al.). Mid to long term outcome sows excellent function and analgesia. Complication rates are low and the necessity for revision remains low

Cephalasporin antibiotics have been commonly used for prophylaxis against surgical site infection. To prevent Clostridium difficile, the preferential use of agents such as flucloxacillin and gentamicin has been recommended. The aim of this study was to investigate the bone penetration of these antibiotics during hip and knee arthroplasty, and their efficacy against Staphylococcus aureus and S. epidermidis.

Bone samples were collected from 21 patients undergoing total knee arthroplasty (TKA) and 18 patients undergoing total hip replacement (THA). The concentration of both antibiotics was analysed using high performance liquid chromatography. Penetration was expressed as a percentage of venous blood concentration. The efficacy against common infecting organisms was measured using the epidemiological cut-off value for resistance (ECOFF).

The bone penetration of gentamicin was higher than flucloxacillin. The concentration of both antibiotics was higher in the acetabulum than the femoral head or neck (p=0.007 flucloxacillin; p=0.021 gentamicin). Flucloxacillin concentrations were effective against S. aureus and S. epidermis in all THAs and 20 (95%) TKAs. Gentamicin concentrations were effective against S.epidermis in all bone samples. Gentamicin was effective against S. aureus in 11 (89%) femoral samples. Effective concentrations of gentamicin against S. aureus were only achieved in 4 (19%) femoral and 6 (29%) tibial samples in TKA.

Flucloxacillin and gentamicin was found to effectively penetrate bone during arthroplasty. Gentamicin was effective against S. epidermidis in both THA and TKA, while it was found to be less effective against S. aureus during TKA. Bone penetration of both antibiotics was less in TKA than THA.

Tranexamic Acid (TA) has been shown to reduce transfusion rates in Total Knee Replacement (TKR) without complication. In our unit it was added to our routine enhanced recovery protocol. No other changes were made to the protocol at this time and as such we sought to examine the effects of TA on wound complication and transfusion rate.

All patients undergoing primary TKR over a 12 month period were identified. Notes and online records were reviewed to collate demographics, length of stay, use of TA, thromboprophylaxis, blood transfusion, wound complications and haemoglobin levels. All patients received a Columbus navigated TKR with a tourniquet. Only patients who received 14 days of Dalteparin for thromboprophylaxis were included.

124 patients were included, 72 receiving TA and 52 not. Mean age was 70. Four patients required a blood transfusion all of whom did not receive TA (p = 0.029). Mean change in Hb was 22 without TA and 21 with (p = 0.859). Mean length of stay was 6.83 days without Tranexamic Acid and 5.15 with (p < 0.001). 15% of patients (n=11) of the TA group had a wound complication, with 40% of patients (n=21) in the non TA group (p = 0.003). There was one ultrasound confirmed DVT (non TA group). No patients were diagnosed with pulmonary embolus.

In our unit we have demonstrated a significantly lower transfusion rate, wound complication rate and length of stay, without any significant increase in thromboembolic disease with the use of TA in TKR.

INTRODUCTION. Cementless Total Hip Replacement surgery is a well established procedure for relative young patients with severe hip disease. Excellent long term clinical results have been published on the performance of the femoral component. With growing clinical experience, our concern focused on excessive wear of the Ultra High Molecular Weight Polyethylene (UHMWPE) ringloc liner of the Mallory Head cementless Total Hip Prosthesis. After its introduction in our clinic in 1997, this implant is still in use without any modification. We were concerned that due to premature liner wear, the performance of this implant would not be compliant with the international guideline on implant survival (NICE guidelines: at 10 year follow up, 90% of all implants should still be in situ). Our objective was to establish the amount of liner wear in our first 200 MH implants. METHODS. Our first 200 patients consecutively treated with Mallory Head prostheses were followed up to obtain a recent digital image. Follow up was complete for 181 (90.5%) of our 200 patients. Ten had died and nine were not able or willing to come for follow up. The mean duration of follow up was 8.3 years (range: 8–13). The 181 recent digital images were classified as either excessive wear or no excessive wear by two independent orthopedic surgeons. Next, liner wear was measured in the 2D frontal plane using PolyWare Pro/3D Digital Version Rev 5.1 software (Draftware Developers, Conway, USA). A threshold for excessive liner wear was set at 0.2mm/year, according to literature. RESULTS. Using software for measuring PE wear, 46.7% of all patients had excessive UHMWPE wear (> 0.2mm/yr). There was no relation between the amount of wear and BMI, gender, component size or the acetabular inclination angle. Thirteen patients (6.5%) were revised. Nine of these revisions were for excessive liner wear or aseptic loosening (4.5%). For now, our series of cementless Mallory Head prostheses is compliant with the NICE guideline on implant survival. However, with the measured amount of wear we expect to see a significant increase in the number of revisions for liner wear in the near future. DISCUSSION. Our clinical observation of premature UHMWPE wear proved correct. The measured amount of UHMWPE wear is consistent with the few other studies published on this subject. Although we present a retrospective study, limiting the strength of our results, we have included a large group of patients with acceptable loss to follow up. It is unclear if the observed wear will lead to a sharp increase in the number of revisions within the next few years. Possibly, future revisions will be complicated by loss of acetabular bone stock following the pathofysiological reaction to wear particles. Our results can probably be generalised for any district hospital

Introduction

The purpose of this study was to compare the clinical outcomes and complications following bilateral simultaneous total knee arthroplasty in high body mass index (BMI) patients(>30kg/m²) to those of patients with a BMI<30 kg/m².

This study assesses the incidence of noise in ceramic on ceramic (COC) bearings compared to metal on polyethylene (MOP) bearings. Noise after MOP implants has rarely been studied and they never been linked to squeaking.

We have developed a noise characterising hip questionnaire and sent it along with the Oxford Hip Score (OHS) to 1000 patients; 509 respondents, 282 COC and 227 MOP; median age 63.7 (range 45–92), median follow up 2.9 years (range 6–156 months).

47 (17%) of the COC patients reported noise compared to 19 (8%) of the MOP patients (P=0.048). 9 COC and 4 MOP patients reported their hip noise as squeaking. We found the incidence of squeaking in the COC hips to be 3.2% compared to 1.8% in the MOP hips. Overall, 27% patients with noise reported avoiding recreational activities because of it and patient's with noisy hips scored on average 4 points less in the OHS (COC: P=0.04 and MOP: P =0.007).

This is the first study to report squeaking from MOP hip replacements. We therefore believe the squeaking hip phenomenon is not exclusive to hard bearings. Surprisingly, only a small proportion of patients described nose from their as a ‘squeak’. Noisy hip implants may have social implications, and patients should be aware of this. We have shown a relationship between noise and a lower OHS. However, longer follow-up and further study is needed to link noise to a poorly functioning implant.

Introduction

Hip wear simulation is a widely used technique for the pre-clinical evaluation of new bearing designs. However, wear rates seen in vitro can often be significantly different to those seen clinically. This can be attributed to the difference between the optimal conditions in a simulator and wide ranging conditions in real patients.

This study aimed to develop more clinically relevant simulator tests, looking specifically at the effects of cup inclination angle (in vivo) and stop-dwell-start (SDS) protocols on a clinically available product.

Total hip replacements have been shown to give superior outcomes in patients with intracapsular fractures of the neck of femur compared with hemiarthroplasty. Collarless uncemented femoral stems give excellent long term results in elective hip replacements but there are few studies looking at their outcomes in fractured neck of femur patients. There is some concern that in trauma patients bone quality maybe inferior as most neck of femur fractures are secondary to osteoporosis. The presence of osteoporosis and subsequent widened femoral canal may compromise the mechanical stability of uncemented femoral stems and result in early subsidence, which can lead to altered leg length and decreased hip stability. The aim of this study was to assess whether early subsidence occurred when collarless uncemented stems were used to treat patients with fractures of the neck of femur.

Post-operative radiographs of 33 patients, mean age 71, who underwent an uncemented collarless total hip replacement for a fracture, were reviewed. The distance from the calcar to the tip of the prosthesis was measured for each patient on the initial post operative radiograph and again on the follow-up radiograph at 6 months post operation. Any subsidence was recorded and magnification for each radiograph was calculated by measuring the diameter of the femoral head, which was known to be 36mm. Distances were then adjusted for magnification. The same procedure was performed on 36 age-matched patients, mean age 71, who underwent elective uncemented total hip replacements for osteoarthritis. Hospital notes for each patient were reviewed to assess for complications and DEXA scan results for trauma patients were also evaluated where available.

The mean femoral stem subsidence was significantly greater in the fracture cohort than in elective patients (p = 0.001) with mean subsidence of 4.07mm (range 0.02–18.5mm) and 1.57mm (range 0–5.5mm) respectively. In the fracture cohort there were 3 revisions within 6 months of surgery, 1 for infection and 2 for femoral stem subsidence leading to dislocation. There were no revisions in the elective cohort. DEXA scan results were available for 21 of the 33 fracture cohort patients. All these patients had abnormal bone density with 52% being osteoporotic and 48% osteopenic.

This study showed that collarless uncemented stems subsided significantly when performed for fractures and had a high early revision rate. We therefore recommend that cemented or collared femoral stems be used in patients with femoral neck fractures requiring total hip replacement to reduce the risk of femoral stem subsidence.

Background. Previous data from our institution show that more than half of all prosthetic joint infections are due to S. aureus. A significant proportion of these bacteria may have an endogenous source. Detecting and treating asymptomatic S. aureus nasal carriers preoperatively has been shown to reduce the risk of infection. Material and Methods. This is an ongoing prospective study that started in March/2009 and involves primary total knee or hip arthroplasties candidates. So far preoperative nasal swab cultures were performed in 211(61%) out of 347 patients operated until April/2010. Carriers are identified and randomly chosen for preoperative treatment consisting of nasal mupirocin twice a day and daily cloro-hexidine baths in the 5 days that precede surgery. Antibiotic prophylaxis is cefazolin 24hours adding a single vancomycin dose in MRSA carriers. Results. Around 30% (64/211) of patients presented Saureus nasal carriage and 6 of them (9.4%) were methicilin-resistant. Infection rate was lower in the non-carriers: 1.36% (2/147). The group of 33 untreated carriers so far has the higher prevalence of infection (6.06%; Odds ratio=4.677; p=0.098). In the 31 treated carriers there was only one infection to date (3.23%; Odds ratio=2.371; p=0.463). The 136 patients control group in which no preoperative nasal culture was made registered 4 infections (2.94%; Odds ratio=2.197; p=0.356). Five out of the nine infections involved S. aureus. We further isolated 3 S. epidermidis, 1 enterococcus and 2 gram-negatives. Discussion. It seems that two S. aureus infections were due to endogenous contamination as the infecting bacteria possesses the exact same phenotype as the colonizing preoperative one (one untreated and one treated carrier). In other two S. aureus cases the seeding appears exogenous (a preoperative negative culture and a infecting bacteria different than the preoperative screening). One infection was registered in a non-studied patient. Accordingly, exogenous contamination seems responsible for at least 6 out of 9 infections. Conclusion. These preliminary results suggest that S. aureus colonization may be an endogenous risk factor for prosthetic joint infection that can be influenced. However exogenous contamination is still a major risk factor in our institution