C. Difficile infections in elderly patients with hip fractures is associated with high morbidity and mortality. Antibiotic regimens with penicillin and its derivatives is a leading cause. Antibiotic prophylactic preferences vary across different hospitals within NHS. We compared two antibiotic prophylactic regimens - Cefuroxime only prophylaxis and Teicoplanin with Gentamicin prophylaxis in fracture neck of femur surgery, and evaluated the incidence of C. Difficile diarrhea and Surgical Site Infection (SSI). To assess the Surgical Site Infection and C. Difficile infection rate associated with different regimens of antibiotics prophylaxis in fracture neck of femur surgery. Data was analyzed retrospectively. Neck of femur fracture patients treated surgically from 2009 in our unit were included. Age, gender, co morbidities, type of fracture, operation, ASA grade was collected. 1242 patients received Cefuroxime only prophylaxis between January 2009 and December 2012 (Group 1) and 486 patients received Teicoplanin with Gentamicin between October 2015 and March 2017 (Group 2). There were 353 males and 889 female patients in Group 1 and 138 males and 348 female patients in Group 2. The co morbidities in both groups were comparable. Incidence of C. Difficile diarrhea and Surgical Site Infection (SSI) was noted. Statistical analysis with chi square test was performed to determine the ‘p’ value. C. Diff diarrhea rate in Group 2 was 0.41 % as compared to 1.29 % in Group 1. The Surgical Site Infection (SSI) rate in Group 2 was 0.41 % as compared to 3.06 % in Group 1. The comparative results were statistically significant (p = 0.0009). Prophylactic antibiotic regimen of Teicoplanin with Gentamicin showed significant reduction in C. Difficile diarrhea & Surgical Site Infection in fracture neck of femur patients undergoing surgery

Prompt mobilisation after the Fracture neck of femur surgery is one of the important key performance index (‘KPI caterpillar charts’ 2021) affecting the overall functional outcome and mortality. Better control of peri-operative blood pressure and minimal alteration of renal profile as a result of surgery and anaesthesia may have an implication on early post-operative mobilisation. Aim was to evaluate perioperative blood pressure measurements (duration of fall of systolic BP below the critical level of 90mmHg) and effect on the post-operative renal profile with the newer short acting spinal anaesthetic agent (prilocaine and chlorprocaine) used alongside the commonly used regional nerve block. 20 patients were randomly selected who were given the newer short acting spinal anaesthetic agent along with a regional nerve block between May 2019 and February 2020. Anaesthetic charts were reviewed from all patients for data collection. The assessment criteria for perioperative hypotension: Duration of systolic blood pressure less than 90 mm of Hg and change of pre and post operative renal functions. Only one patient had a significant drop in systolic BP less than 90mmHg (25 minutes). 3 other patients had a momentary fall of systolic BP of less than 5 minutes. None of the above patients had mortality and had negligible change in pre and post op renal function. Only one patient in this cohort had elevation of post-operative creatinine levels but did not have any mortality. Only 1 patient died on day 3 post operatively who had multiple comorbidities and was under evaluation for GI cancer. Even in this patient the peri-operative blood pressure was well maintained (never below 90mmHg systolic) and post-operative renal function was also shown to have improved (309 pre-operatively to 150 post-operatively) in this patient. The use of short-acting spinal anaesthesia has shown to be associated with a better control of blood pressure and end organ perfusion, less adverse effects on renal function leading to early mobilisation and a more favourable patient outcome with reduced mortality, earlier mobilisation, shorter hospital stay and earlier discharge in this elderly patient cohort

Total hip replacement (THR) is an option in a subset of patients with a neck of femur (NOF) fracture. The Scottish Intercollegiate Guidelines Network (SIGN) and National Institute for Clinical Excellence (NICE) provide guidance on the use of THR in patients with a NOF fracture. We compare our experience and recommend changes at a local level to allow successful implementation of the guideline to improve patient care. From July 2008 to July 2011, 36 THRs preformed for trauma were identified retrospectively by cross-referencing several databases (Bluespier, Worcestershire, UK and surveillance of Surgical Site Infection (SSI), Scotland). 7 exclusions (3 failed internal fixation, 1 chronic NOF fracture, and 2 extra-capsular fractures) leaving 29 patients. All operations were carried out under the supervision of a hip surgeon. Outcome data (see results) was collected from electronic sources. Statistical analysis preformed using Fisher's exact test for categorical data. Median age 62 years (44–88), time to surgery 4 days (2–8), American association of anaesthesia grade 2 (2–4) and hospital stay was 12 days (6–18). The first operator was a consultant in 23 cases and registrar in 6. 9 hips were cemented, 5 uncemented and 15 hybrid. 13 (44.8%) patients had a complication including 8 major (27.6%) complications. A blood transfusion was required in 11 (37.9%) patients. There were 2 (6.9%) deaths. A delay to surgery of more than 2 days was associated with increased risk of major complication (p< 0.03). ASA, Age, Grade of surgeon or Cement not associated with major complications. Our results are inferior to those in the literature. We have identified potential causes; mainly a delay to surgery increasing risk of major complication. In keeping with the current guidelines we recommend that local pathways are instigated to ensure THRs for trauma may be preformed in a timely fashion

The Royal College of Surgeons of England (RCS) Good Surgical Practice guidance identifies essential criteria for surgical operation note documentation. The current quality improvement project aims to identify if using pre-templated operation notes for documenting fractured neck of femur surgery results in improved documentation when compared to free hand orthopaedic operation notes. A total of fourteen categories were identified from the RCS guidance as required across all the operations identified in this study. All operations for the month of October 2021 were identified and the operation notes analysed. Pre-templated operation notes were compared to free hand operation notes. 97 cases were identified, of which 74 were free hand operation notes and 23 were pre-templated fractured neck of femur operation notes. All fourteen categories were completed in 13 (57%) of the templated operation notes vs 0 (0%) in the free hand operation notes (odds ratio 0.0052, 95% CI 0.0003 to 0.0945, p < 0.001). The median total number of completed categories was significantly higher in the templated op-note group compared to the free hand op-note group (templated median 14, range 12-14, vs. free hand median 11, range 9 to 13, p < 0.001). Logistic regression analysis of operation notes written by Registrars or Consultants identified Registrars as more likely to document the antibiotic prophylaxis given (p = 0.025). Use of pre-templated operation notes results in significantly improved documentation. Adoption of generic pre-templated operation notes to improve surgical documentation should be considered across all operations

Abstract. BACKGROUND. Hemi-arthroplasty (HA) as a treatment for fractured neck of femur has slightly increased since 2019 and remarkably after the COVID pandemic. The main drawback of the treatment is ongoing cartilage deterioration that may require revision to THR. OBJECTIVE. This study assessed cartilage surface damage in hip HA by reproducing anatomical motion and loading conditions in a hip simulator. METHODS. Experimental design. HA tests were conducted using porcine acetabula and CoCr femoral heads. Five groups (n=4) were included: a control group comprising natural tissue and four HA groups where the acetabula were paired with metal heads to allow radial clearance (RC) classed as small (RC<0.6mm), large (2mm<RC<4mm), extra-large (4mm<RC), and oversized (RC<−0.6mm). Tests were carried out in an anatomical hip simulator that reproduced a simplified twin peak gait cycle, adapted for porcine hip joints, from the ISO 14242 standard for wear of THR prostheses (peak load of 900N). The test length was 6 hours, with photogrammetry taken at 1-hour intervals. Ringers solution was used as a lubricant. RESULTS. No changes were observed in the control group. However, cartilage surface changes were observed in all hemi-arthroplasty groups. Discolouration on the cartilage surface was noticeable at the posterior-superior part of the acetabulum after 1-hour (extra-large and oversized groups). Damage severity and location were characteristic of each clearance group. Of all the groups, the oversized group showed more significant damage. No labrum separation was seen after the simulation. CONCLUSIONS. These results are relevant to understand the effect of femoral head clearance on cartilage damage risk after HA. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Abstract. Objectives. Hip instability following total hip arthroplasty in treatment of intracapsular neck of femur fractures is reported at 8–11%. Utilising the principle of a small articulation to minimize the problems of wear coupled with a large articulation, dual-mobility total hip arthroplasty prostheses stabilise the hip further than conventional fixed-bearing designs. The aim of this study is to compare the rate of dislocation and complication between standard fixed-bearing and dual-mobility prostheses for the treatment of intracapsular neck of femur fractures. Methods. A four-year retrospective review in a large district general hospital was completed. All cases of intracapsular neck of femur fractures treated with total hip arthroplasty were identified through the theatre logbooks. Patient's operative and clinical notes were retrospectively reviewed to collect data. Results. A total of 91 patients underwent total hip arthroplasty for intracapsular neck of femur fracture in the four-year period. 61.5% were dual-mobility design versus 28.5% had fixed-bearing implants. There were no statistical differences between patient group characteristics. Choice of implant was dependent on surgeon preference. There was a 0.0% dislocation rate in the dual-mobility group versus 8.6% in the fixed-bearing prosthesis group. All dislocations occurred in patients who underwent total hip arthroplasty with 36.0mm fixed-bearing prosthesis via posterior surgical approach. There was no statistical difference in mortality between both groups. Conclusion. There was an increasing trend of towards the use of dual-mobility prosthesis for fractured neck of femur within this department with excellent outcomes. Dual-mobility designs provide reduced dislocation rates in total hip arthroplasty in intracapsular neck of femur fractures compared to standard fixed-bearing designs at this institution. The authors recommend that all orthopaedic staff consider the use of dual-mobility prostheses in suitable patients and ensure trainees are suitably trained in use of dual-mobility designs. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. Fractured neck of femurs cause substantial morbidity and mortality in elderly patients and represent a huge financial burden to the NHS. Hip fracture patients are generally malnourished on admission, often having poor nutritional inpatient intake, hindering recovery and increasing chances of “unfavourable outcome.” Nutritional care is included in intercollegiate guidelines for management of fractured neck of femur patients, but is nutrition a management priority in clinical practice?. Study Aim. To evaluate protein and energy intake of acute fractured neck of femur patients depending on admission MMSE, and compare these to department of health targets. Method. 40 acute fractured neck of femur admissions were recruited between December 08-March 09 and put into three groups depending on admission MMSE. Initial nutrition screening information (mid-arm circumference, grip strength, MUST score) was recorded and through food charts daily kcal and protein intake were calculated for a three day period. Results. 100% of patients recruited were high risk of malnutrition on admission. Overall average daily calorie intake over 3 days was 385.9 kCal, average protein intake was 14.1g. Intake for each group was well below recommended target intake of 1810kCal and 46.5g, p<0.05. Discussion. On admission all 40 patients included were classified high risk for malnutrition, therefore in need of dietetic and nutritional intervention. Two patients received dietician input and oral supplementation. Recorded nutritional intake was very low, well below target nutrient intakes for this population even before extra requirement due to the stress response is accounted for. Whilst there is a paucity of hard evidence linking poor nutrition to clinical outcome, this is likely to be detrimental to rehabilitation from surgery. Conclusion. Despite attempted adherence to NICE nutrition guidance, involving screening tools, care plans and protected mealtimes; acutely unwell, malnourished patients are not receiving their basic nutritional requirements

Introduction. Prosthetic joint infection (PJI) is an uncommon but serious complication of hip replacement. A recent systematic review of patient risk factors for PJI identified male gender, smoking status, increasing BMI, steroid use, previous joint surgery and comorbidities of diabetes, rheumatoid arthritis and depression as risk factors for developing PJI. Limitations of the current literature include the short term follow up of most published studies. We investigated the role of patient, surgical and healthcare factors on the risk of revision of a primary hip replacement for PJI at different time-points in the post-operative follow-up. It is important that those risk factors are identified so that patients can be appropriately counselled according to their individual risk profile prior to surgery and modifiable factors can be addressed to reduce the risk of PJI at an individual and healthcare system level. Materials and Methods. Primary hip replacements and subsequent revision procedures performed for PJI from 2003–2014 were identified from the National Joint Registry (NJR). Patient (age, gender, ASA grade, BMI), perioperative (surgical indication, type of anaesthesia, thromboprophylaxis regime, surgical approach, hip replacement and bearing surface and use of femoral or acetabular bone graft) and healthcare system characteristics (surgeon grade, surgical volume) were linked with data from Hospital Episode Statistics to obtain information on specific ethnicity and comorbidities (derived from the Charlson index). Multilevel piecewise exponential non-proportional hazards models were used to estimate their effects at different post-operative periods (0–3 months, 3–6 months, 6–12 months, 12–24 and >24 months post-operation). Results. The index hip replacements consisted of 623,253 primaries with 2,705 subsequently revised for PJI, 14% within 3 months, 8% between 3–6 months, 14% between 6–12 months, 22% between 1–2 years and 42% ≥2 years after the index procedure. Risk factors for revision of PJI included male gender, high BMI, high ASA grade and younger age. Their effects were period-specific. Patients with chronic pulmonary disease, diabetes or dementia had high early risk of revision for PJI, as did patients operated for a fractured neck of femur (<3 months). Metal-on-metal bearings (>12 months) and lateral surgical approach (≥3 months) also influenced the mid- and long-term revision risk for PJI. No or modest associations were found with the operating surgeon grade, surgical volume and hospital surgical volume. Conclusion. The effects of patient, perioperative and healthcare system risk factors for PJI after primary hip replacement are time-dependent. Modifiable risk factors such as the type of surgical approach and bearing surface have also been found

To report the case of an asymptomatic simultaneous bilateral neck of femur fracture following vitamin D deficiency which was missed, misdiagnosed and treated for coexisting severe bilateral osteoarthritis knee. A male aged 62 years presented with severe osteoarthritis of both knee joints confining him to bed about eight weeks prior to presentation. The patient did not have any complaints pertaining to his hip joints/axial skeleton. Examination of the hip joints revealed only crepitus with absence of straight leg rising. Radiological survey showed bilateral displaced fracture neck of femur. He had elevated serum alkaline phosphatase; 119IU/L(N:39–117IU/L), decreased Serum 25 (OH) Vit D level;6.03ng/ml(N:7.6–75ng/ml), decreased spot urinary calcium;78mg/day(N:100–300mg/day) with normal serum calcium, phosphorus and highly raised parathormone levels;142.51pg/ml(N:12–72pg/ml). Tc-99 Bone scan showed increased radiotracer uptake in both the hip joints and knee joints. Bone Mineral Density was in favour of osteoporosis. Biopsy fromthe heads of both femurs also revealed osteoporosis. Bilateral staged total hip arthroplasty was done and he was put on Vitamin D replacement therapy. Patient was on regular monthly follow-up for intial one year and three monthly follow-up thereafter. At present with three year follow-up patient is community ambulant with a walking frame. Despite medical advice patient had denied total knee arthroplasty for osteoarthritis of his knee joints. Asymptomatic simultaneous bilateral neck of femur fracture is a rare injury and poses a diagnostic challenge to the treating orthopaedic surgeon with its bizarre clinical picture. Similar presentation of metabolic bone disease can be easily missed without a proper screening, keeping in mind a high index of suspicion for the above disorders. Besides proper clinical examination of both hip and knee joint should be performed in patients presenting with bilateral knee pain. A good functional outcome may be achieved with prompt surgical intervention and medical treatment

Recent NICE guidance recommends use of a well proven cemented femoral stem for hip hemiarthroplasty in management of fractured neck of femur. The Exeter Trauma Stem (ETS) has been designed based on the well proven Exeter hip stem. It has a double taper polished stem design, proclaimed to share geometry and surface finish with the Exeter hip. This study investigated the surface finish of the two stems in order to investigate the hypothesis that they were different. Two ETS and two Exeter stems were examined using a profilometer with a sensitivity of one nanometer. Macroscopic visual inspection showed that the two Exeter stems had significantly smoother surface finish than the ETS stems. The roughness average (RA) values on the ETS stems were approximately an order of magnitude higher than those of the Exeter stems, mean of 0.235μm compared with 0.025μm (p<0.0001). This difference in surface finish has implications for the biomechanical functioning of the stem. Previous change of the Exeter stem to a matt surface-finish in 1976 resulted in a significant increase in stem failure rates and an understanding of the importance of the polished surface-finish in order to function within a taper-slip philosophy. By changing the surface finish in the ETS stem, longevity of the implant may similarly be affected. Clinical results have yet to be published demonstrating this. We recommend the manufacturer reconsiders the surface finish of the ETS stem to ensure it functions as well as the Exeter primary stem with which it shares a design philosophy

Hip fracture is a common and serious injury affecting the elderly. Many patients have co-morbidities which may need to be investigated and treated before surgery but, conversely, delay in surgical management of these patients leads to increased morbidity and mortality. The Scottish Hip Fracture Audit (SHFA). 1. conducted in 2007 showed variations between hospitals in postponement rates for medical reasons. The report referred to 11 major clinical abnormalities described by McLaughlin. 2. that were associated with poor postoperative outcomes and should be corrected before surgery. This prospective audit took place in Monklands hospital for a duration of 6 weeks. All patients admitted to the orthopaedic firm from 14. th. Oct 2012 to 26. th. November 2012 with confirmed fracture neck of femur were prospectively included in the audit. A detailed review of the notes took place to identify whether delays were appropriate according to McLaughlin. There were a total of 23 patients admitted during the audit period of which 21 were operated on and 2 patients treated conservatively. The mean age of this cohort was 82.8 (range 55–91) with a male to female ratio of 1:1.3. Sixteen cases (76%) were operated on within 48 hours of admission (11 cases – 52% within 24 hours). Five cases (24%) were delayed by more than 48 hours. Three cases (14%) were delayed due to lack of theatre time. Two patients (9.5%) were delayed due to request of ECHO for ?new murmur. Our practice of managing hip fracture patients is similar to other units in Scotland with a deferral rate of approximately 25%. The patients who have a major clinical abnormality were appropriately investigated and treated before the surgery. Further improvement in management of the theatre time is needed as surgery is delayed for >24 hours in approximately 15% of medically fit hip fracture patients

Currently, the cement being used for hemiarthroplasties and total hip replacements by the authors and many other surgeons in the UK is Palacos® (containing 0.5g Gentamicin). Similar cement, Copal® (containing 1g Gentamicin and 1g Clindamycin) has been used in revision arthroplasties, and has shown to be better at inhibiting bacterial growth and biofilm formation. We aim to investigate the effect on SSI rates of doubling the gentamicin dose and adding a second antibiotic (clindamycin) to the bone cement in hip hemiarthroplasty. We randomised 848 consecutive patients undergoing cemented hip hemiarthroplasty for fractured NOF at one NHS trust (two sites) into two groups: Group I, 464 patients, received standard cement (Palacos®) and Group II, 384 patients, received high dose, double antibiotic-impregnated cement (Copal®). We calculated the SSI rate for each group at 30 days post-surgery. The patients, reviewers and statistician were blinded as to treatment group. The demographics and co-morbid conditions (known to increase risk of infection) were statistically similar between the groups. The combined superficial and deep SSI rates were 5 % (20/394) and 1.7% (6/344) for groups I and II respectively (p=0.01). Group I had a deep infection rate 3.3 %(13/394) compared to 1.16% (4/344) in group II (p=0.082). Group I had a superficial infection rate 1.7 % (7/394) compared to 0.58% (2/344) in group II (p=0.1861). 33(4%) patients were lost to follow up, and 77 (9%) patients were deceased at the 30 day end point. There was no statistical difference in the 30 day mortality, C. difficile infection, or the renal failure rates between the two groups. Using high dose double antibiotic-impregnated cement rather than standard low dose antibiotic-impregnated cement significantly reduced the SSI rate (1.7% vs 5%; p=0.01) after hip hemiarthroplasty for fractured neck of femur in this prospective randomised controlled trial

Osteoporosis (OP) results in a reduction in the mechanical competence of the bone tissue of the sufferers. In skeletal sites such as the proximal femur and the vertebrae, OP manifests itself in low trauma fragility fractures which are debilitating for the patient. The relationships between the compressive strength of cancellous tissue and its apparent density are well established in studies of the past. Recently the authors have presented a method able to assess the fracture toughness properties of cancellous bone (1), a challenging cellular material which can exhibit large elasto-plastic deformations. The in-vitro measurement of fracture toughness alongside the customary compressive strength can provide a comprehensive assessment of the mechanical capacity of cancellous bone, which will reflect closer its ability to resist crack initiation. The aims of the present study were: (1) to examine whether the observed fracture toughness deterioration can also be detected by non-invasive quantitative ultrasound (QUS); and (2) to provide rational evidence for the well proven ability of QUS to predict directly ‘risk of fracture’. 20 femoral heads were obtained from donors undergoing emergency surgery for a fractured neck of femur. QUS investigations of the calcaneus, proximal phalanx and distal radius were undertaken within 72 hours of surgery. 128 fracture toughness samples and 20 compression cores were manufactured and tested. Two clinical QUS systems were used to obtain in-vivo scan data and then directly compared those to the density, porosity and the fracture mechanics of tissue extracted from the same individuals. The results demonstrated not only that there was a significant link between in-vivo determined QUS values for the calcaneus and finger to the density of the density of the femoral head; but that there was also a significant link between the QUS results from the calcaneus and the fracture toughness of the cancellous bone from the femoral head. These results point towards a systemic effect of osteoporosis which affects similarly different parts of the skeleton and supports the use of clinical QUS systems as a diagnostic tool for the prediction of fracture risk

Despite the development of skeletal or mesenchymal stem cell (MSC) constructs aimed at creating viable cartilage and bone, few studies have examined the effects of cytokines present in rheumatoid arthritis (RA) and osteoarthritis (OA) synovial tissues, or inhibition of these, on such constructs. This work addresses these issues using both in vitro and in vivo approaches and examines potential ways of overcoming the effects of cytokines on the integrity of cartilage and bone constructs. Synovial samples were obtained from RA or OA (n=10) patients undergoing elective hip or knee arthroplasty at Southampton General Hospital. Full ethical approval was obtained. Control bone marrow-derived stromal cells were obtained from patients undergoing emergency fractured neck of femur repair, cultured in basal, osteogenic (ascorbate and dexamethasone) and chondrogenic (transforming growth factor beta (TGFbeta3)) conditions. Differentiation towards bone and cartilage was assessed using alkaline phosphatase (ALP) staining, ALP and DNA biochemical assays and analysis of osteogenic/chondrogenic gene expression using real time polymerase chain reaction (rt-PCR). Exogenous interleukin-1 (IL-1) (10ng/mL), tumour necrosis factor alpha (TNFalpha) (10ng/mL) or interleukin-6 (IL-6) (100ng/mL) was added and effects on differentiation noted. RA and OA synovial samples were digested, cultured for 48 hours then centrifuged to produce supernatants. Cytokine profiles were determined using ELISA. These supernatants were then added to MSCs and their effects on differentiation assessed. Mesenchymal cultures in osteogenic media with IL-1 showed an additive osteogenic effect on biochemical assays. TNF exerted a less marked and IL-6 no apparent effect on osteogenic differentiation. ALP expression by rt-PCR correlated with these findings. Addition of supernatants to mesenchymal cultures produced a marked osteogenic profile that was IL-1 and TNFalpha concentration dependent, correlating with lower supernatant dilutions on initial ELISA analysis. Preliminary studies indicate that exogenous IL-1 and TNFalpha modulate the osteogenic phenotype in MSCs in vitro. OA and RA synovial supernatants affect skeletal cell differentiation. Variations in cytokine profiles between supernatants require analysis for potential confounders. A larger study is underway to investigate these effects, the effects of cytokines on skeletal cell differentiation on commercially available scaffolds both in vitro and in an in vivo murine model of bone formation

Bone related adverse events including failure of implant osseo-integration, periprosthetic fracture, femoral neck narrowing, and unexplained pain occur more frequently following metal-on-metal hip resurfacing (MoMHR) versus total hip arthroplasty (THA). The exact mechanism for the adverse effects is still unclear and may be due to the direct effect on bone cells of metal ions released from the prostheses. The aim of the present study was to determine the effect of clinically relevant combinations of metal ions on osteoblast cell survival and function. To assess cell proliferation and alkaline phosphatase (ALP) activity of osteoblasts, human osteoblast cells (SaOS-2), were cultured in 96-well plates for 24-hours and then treated with metal ions. Cell proliferation was measured at day 3 and day 7 using MTS assay, whilst ALP activity was assessed at day 3 by measuring pNPP substrate hydrolysis by the cell lysate. Mineralisation ability of the cells was assessed in 24-well plates cultured until day 21 and staining the calcium deposits using Alizarin red. All cultures were treated with the IC50 concentration of Co(II) (135μM) and an equivalent Cr(III) concentration (1Co(II):1Cr(III)). After 3 days, Co(II) at an IC50 concentration decreased osteoblast proliferation as expected, but no further decrease in proliferation was observed with the 1Co(II):1Cr(III) combination treatment. However, after 7 days, a further significant decrease (P<0.05) in proliferation was observed with the combination treatment compared to Co(II) IC50. A similar significant decrease (P<0.01) was observed for ALP activity at day 3 with 1Co(II):1Cr(III) compared to Co(II) alone. For mineralization, a significant reduction (P<0.0001) was observed for Co(II) IC50 concentration, however no further reduction was seen with the 1Co(II):1Cr(III) combination treatment. The observed decrease in cell proliferation and ALP activity with combination treatments suggest an additive detrimental effect compared to single ions alone. The mineralisation ability did not show any additive effect due to cell toxicity of chronic exposure to IC50 concentrations calculated from 3 day proliferation cultures. The results suggest that presence of both cobalt and chromium ions in the periprosthetic environment have more severe detrimental effect on osteoblasts than single ions alone and extend our understanding of the periprosthetic bone health

The renewed interest in the clinically proven low wear of the metal-on-metal bearing combined with the capacity of inserting a thin walled cementless acetabular component has fostered the reintroduction of hip resurfacing. As in other forms of conservative hip surgery, i.e. pelvic osteotomies and impingement surgery, patient selection will help minimize complications and the need for early reoperation. Patient Selection and Hip Resurfacing. Although hip resurfacing was initially plagued with high failure rates, the introduction of metal on metal bearings as well as hybrid fixation has shown excellent survivorships of 97 to 99% at 4 to 5 years follow-up. However, it is important to critically look at the initial published results. In all of these series there was some form of patient selection. For example, in the Daniel and associates publications, only patients with osteoarthritis with an age less than 55 were included with 79% of patients being male. Treacy and associates stated that: “the operation was offered to men under the age of 65 years and women under the age of 60 years, with normal bone stock judged by plain radiographs and an expectation that they would return to an active lifestyle, including some sports”. However in the materials and methods, although the mean age is 52 years, the range is from 17 to 76 years including some patients with rheumatoid arthritis as well as osteonecrosis. Obviously, some form of patient selection is needed; but how one integrates them is where the Surface Arthroplasty Risk Index (SARI) is useful. With a maximum score of 6, points are assigned accordingly: femoral head cyst >1cm: 2 points; patient weight <82kg: 2 points; previous hip surgery: 1 point; UCLA Activity level >6: 1 point. A SARI score >3 represented a 4 fold increase risk in early failure or adverse radiological changes and with a survivorship of 89% at four years. The SARI index also proved to be relevant in assessing the outcome of the all cemented McMinn resurfacing implant (Corin¯, Circentester, England) at a mean follow-up of 8.7 years. Hips which had failed or with evidence of radiographic failure on the femoral side had a significantly higher SARI score than the remaining hips, 3.9 versus 1.9. Finally, one must consider the underlying diagnosis when evaluating a patient for hip resurfacing. In cases of dysplasia, acetabular deficiencies combined with the inability of inserting screws through the acetabular component may make initial implant stability unpredictable. This deformity in combination with a significant leg length discrepancy or valgus femoral neck could compromise the functional results of surface arthroplasty, and in those situations a stem type total hip replacement may provide a superior functional outcome. In respect to other diagnoses (osteonecrosis, inflammatory arthritis), initial analyses have not demonstrated any particular diagnostic group at greater risk of earlier failure. The only reservation we have is in patients with compromised renal function since metal ions generated from the metal-on-metal bearing are excreted through the urine and the lack of clearance of these ions may lead to excessive levels in the blood. Surgical Technique. Because resurfacing has not been within the training curriculum of orthopaedic surgeons for the last 2 decades, there will most likely be a learning curve in the integration of this implant within clinical practice. This data was confirmed for hip resurfacing when looking at the Canadian Academic Experience where in the first 50 cases of five arthroplasty surgeons only a 3.2% failure rate was noted of which 1.6% were due to neck fracture. Femoral neck fracture can occur because of significant varus positioning as well as osteonecrosis of the femoral head due to either disruption of the blood supply or over cement penetration. Finally, abnormal wear patterns leading to severe soft tissue reactions are being increasingly recognized and are related to either impingement or vertically placed acetabular components. Although impingement has long been recognized after total hip arthroplasty to limit range of motion and in extreme cases to hip instability, the risk after hip resurfacing may be greater since the femoral head-neck unit is preserved. Beaulé and associates have reported that 56% of hips treated by hip resurfacing have an abnormal offset ratio pre-operatively, with the two main diagnostic groups presenting deficient head-neck offset being osteonecrosis and osteoarthritis both of which have been associated with femoroacetabular impingement in the pre arthritic state. Conclusion. Although patients with a high activity level are likely to put their hip arthroplasties at risk for earlier failure, limiting a patient's activity because of fear of revision with a stem type hip arthroplasty has been shown to negatively impact the quality of life at long term follow-up. Thus hip resurfacing arthroplasty plays a significant role in the treatment of hip arthritis by permitting a return to full activities or what the patient perceives as his/her full capacities to do so, permitting them to enjoy a better quality of life without fearing a major hip revision

Maintaining femoral neck cortical thickness may help prevent hip fracture. Fracture initiation probably starts superiorly at flaws, ie where the cortex is thinnest. Whole body computed tomography (QCT) is now being used to study cortical thickness but limited resolution (> 300 micrometers) makes in vivo estimates imprecise, whereas microscopy s resolution approaches 1 micrometer. We have therefore extended our microscopic studies on femoral neck biopsies to include men (14 cases, 26 controls) and women (50 cases, 23 controls), and here provide data on true cortical thickness in subjects with and without hip fracture. Whole femoral neck cross-sections obtained at hemiarthroplasty (or at post-mortem in controls) were embedded in methacrylate, cut, stained and imaged at medium power. Image-J was used to define cortical boundaries and to measure cortical thicknesses at 5 degree intervals of arc from the cross-sections centre of area. We confirmed that the mid-femoral neck (or narrow neck) site, defined as where the ratio of maximum to minimum neck diameter (max:min) is 1.4, shows great asymmetry, with the thick inferior cortical octant averaging over 3mm thickness (mean age 79 years inter-quartile range 74-85). In the superior 3 octants cortical thickness averaged 26% of that seen inferiorly. To assess statistical determinants of cortical thickness, the data were modelled with linear regression in octants after adjusting for subjects age, sex, max:min, and hip fracture status. To achieve normality of residuals the cortical thickness data were log-transformed. 95% of measured cortical thicknesses fell between 45% and 220% of the mean for octant. In the thinner, superior three octants, minimum thicknesses were just under 0.3 mm in the fracture cases ie close to 35% of the subjects mean for octant. Cases had about 17% thinner cortical thicknesses in all octants than controls, while female controls had cortical thicknesses that uniformly averaged 90% of male. In conclusion, compared to gender and age-matched controls, intra-capsular hip facture cases had generalized cortical thinning in all mid-neck octants. This disease effect contrasts markedly with the effect of normal ageing, which thins preferentially the mechanically under-loaded superior cortex and spares the infero-anterior cortex