Introduction. Recently, femoroacetabular impingement has been postulated as an important cause for the development of primary osteoarthritis of the hip. Various studies have shown that primary osteoarthritis of the hip is rare amongst Asians including Indians. We conducted an anthropometric study to evaluate prevalence of abnormal head-neck offset in Indian population and to correlate it with the low prevalence of primary osteoarthritis in Indian population. Material and Methods. We retrospectively evaluated three dimensional CT scans of hips conducted as a part of another project done over a period of two years at our institute. An axial image was created parallel to the central axis of the femoral neck and passing through the centre of the femoral head using coronal scout view. This image was then used to calculate Alpha and Beta angles and head-neck offset ratio. Results. The average alpha angle (45.6°) reported in our study is similar to that reported in a Western population. Similarly, the prevalence of abnormal offset ratio found in our study (11.8%) is similar to the estimated prevalence of 10-15% of FAI in a Western population. Conclusion. We conclude that differences in the prevalence of hip osteoarthritis in Indian and Western populations cannot be explained on the basis of variation in prevalence of FAI and other factors may be responsible

Aims. Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods. A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results. The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion. In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA. Cite this article: Bone Joint J 2024;106-B(3 Supple A):130–136

Introduction. Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of THA, as well as surgical approach, on gait kinetics and kinematics. Purpose. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Methods. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardized implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. Results. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Discussion. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of surgical approach on gait kinetics and kinematics. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardised implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

It is estimated that approximately 3.1 – 7.7% of the general population suffers from primary osteoarthritis of the hip, with up to 42% of these cases being bilateral. The odds of undergoing a contralateral THA after index unilateral THA range from 16–85%. Up to 20% of these patients have the contralateral THA within 5 years. For this patient population, simultaneous bilateral THA may be an appealing option but it remains controversial. Proponents of bilateral simultaneous THA cite advantages such as a single anesthetic exposure, overall shorter length of hospital stay, quicker recovery, earlier return to function, less time off of work, and potential economic advantages. Only recently has there been more data emerging on patients undergoing simultaneous bilateral THA through the direct anterior approach (DAA). The DAA has the distinct advantage of supine positioning that facilitates easy exposure to both hips without the need to reposition the patient onto a fresh surgical incision while performing the second operation. Recent publications suggest that bilateral simultaneous DAA is a safe procedure and may have economic benefits as well. At our institution between 2010 and 2016, a consecutive series of 105 patients (210 hips) undergoing simultaneous bilateral DAA THA and a matched group of 217 patients undergoing unilateral DAA THA by the same surgeon at a single institution were reviewed. The two groups were matched by gender, age, body mass index and date of surgery. There were no significant differences between the two groups in terms of early complications. There were 2 complications in the unilateral group that were intraoperative nondisplaced calcar fractures that were treated with a single cerclage cable and 50% weight bearing for four weeks. There were 6 in-hospital systemic complications in the unilateral group compared to 7 in the bilateral group (p = 0.129). In-hospital systemic complications were similar between the two groups and included urinary retention, cardiopulmonary abnormalities, alcohol withdrawal, and nausea / vomiting. There were a total of 14 30-day follow-up hip-related complications in the unilateral group compared to 5 in the bilateral group (p = 0.06) These complications were similar between the two groups and included wound healing issues, tendinitis / bursitis, deep infection, nerve palsy, stem subsidence, and instability. Intraoperative estimated blood loss (EBL) was 360cc in the unilateral group compared to 555cc in the bilateral group (p < 0.001). The bilateral group had lower postoperative day one (POD1) hemoglobin (9.5 g/dl vs. 10.2 g/dl; p < 0.001). Four percent of unilateral patients required blood transfusion compared to 11% in the bilateral group. There were significant differences between the two groups in terms of distance ambulated on POD1 and length of stay (LOS). On average, the unilateral patients walked 235 feet on POD1 compared to 182 feet for the bilateral patients (p < 0.001). Length of stay was significantly longer in the bilateral group (1.95 days vs. 1.12 days; p < 0.001). All 322 patients involved in the study were discharged to home except for a single patient in the bilateral group who was discharged to a skilled nursing facility. In conclusion, we found no difference in in-hospital or 30-day complication rates when comparing the simultaneous bilateral group to the unilateral group. The main difference when compared to unilateral surgery is increased blood loss yet this did not directly result in specific complications. Simultaneous bilateral DAA THA can be performed safely and without an unacceptably high perioperative complication rate

Modern Metal on Metal hip resurfacing originated from Birmingham in the early 1990’s and is now well estabilished in the U.K. This procdure is gaining acceptance in other parts of the world and is now being performed in many countries in the Asia Pacific region including Australia and India.The demographics of the patient population with hip arthritis in south Asia and western europe is very contrasting. Primary osteoarthritis of the hip is virtually non-existent in the Indian subcontinent wheras it is by far the commonest hip disorder in Europe.Sixty nine percent of patients had primary osteoarthritis as the presenting pathology in the pilot series of metal on metal hip resurfacings from Birmingham. Most patiens in India with hip arthritis are very young and have developed secondary degenerative in the joint due to other specific causes. Thus procedures like the Birminham hip resurfacing which addresses the difficult problem of hip arthritis in the young active adult have a greater role to play in this

Introduction: The C-stem (DePuy, Leeds, UK) is triple tapered, polished and collarless. These features can facilitate distal stem migration within the cement mantle, a phenomenon first noticed on radiographs and later confirmed by radiostrereometric analysis (RSA) for the double tapered polished Exeter stem (Stryker, Mahwah, NJ). Low revision rates are reported for the Exeter stem and the view that early migration predicts later failure has not been confirmed with double tapered designs. If a triple tapered stem has any advantages is however not known. Patients and methods: 33 primary hip arthroplasties with a median age of 66 (46–74) years were followed for 2 years with radiostereometric analysis (RSA) at 3 months, 6 months, 1, 2 and 3 years. The diagnosis was primary osteoarthrosis in all hips. Both migration and rotation were studied. Results: All the stems migrated distally and posteriorly within the cement mantle. The median distal migration was 1.47 mm at 3 years and the median posterior migration was 1.56 mm at 3 years. All the stems rotated towards retroversion and median rotation at 3 years was 2.0°. For all the other directions the prosthesis was stable up to 3 years. Discussion: The C-stem migrates and rotates more than cemented prostheses of other designs. Compared with other tapered prostheses the distal migration is at the same level but posterior rotation is higher and furthermore it migrates posteriorly, which the other tapered stems do not. If this migration/rotation pattern is tolerable without risk of prosthetic failure needs to be studied further, but at present there is no indication from the available clinical results for the C-Stem that this pattern is deleterious

Puropose. Three-dimensional (3D) templating based on computed tomography (CT) in total hip arthroplasty improves the accuracy of implant size. However, even when using 3D-CT preoperative planning, getting the concordance rate between planned and actual sizes to reach 100% is not easy. To increase the concordance rate, it is important to analyze the causes of mismatch; however, no such studies have been reported. This study had the following two purposes: to clarify the concordance rate in implant size between 3D-CT preoperative planning and actual size; and to analyze risk factors for mismatch. Materials and Methods. A single surgeon performed 149 THAs using Trident Cup and Centpillar Stem (Stryker) with CT-based navigation between September 2008 and August 2011. Minimal follow-up was 2 years. Patients with incomplete postoperative CT were excluded from this study. Based on these criteria, the study examined 124 hips in 111 patients (mean age, 60 years, mean BMI 23.2 kg/m2). The preoperative diagnosis was primary osteoarthritis in 8 hips, secondary osteoarthritis in 102 hips, osteonecrosis in 9 hips, rapidly destructive coxopathy in 4 hips and rheumatoid arthritis in 1 hip. We compared cup and stem sizes between preoperative planning and intraoperatively used components. Radiological evaluations were cortical index and canal flare index on preoperative X-rays. We evaluated preoperative planning and postoperative components for cup orientation, cup position, and stem alignment (anteversion, flexion and varus angle) on the CT-navigation system. Fixation of the stem was evaluated by X-ray radiography at 2 years postoperatively according to Engh's criteria. Statistical analysis was performed with the Mann-Whitney U test, and values of P<0.05 were considered statistically significant. Results and Discussion. The concordance rate in cup size between preoperative planning and used implants was 94.4% (117/124 hips) (CS group). A one-size larger cup was used in 4 hips (CO group), and a one-size smaller cup was implanted in 3 hips (CU group). No significant difference was seen between the CS group and the CO or CU groups in change of cup orientation and cup position from planning (P>0.05) (Table 1). The concordance rate of stem size between preoperative planning and used stem was 85.5% (106/124 hips) (SS group). A one-size larger stem than the plan was used in two hips (SO group), and a one-size smaller stem than the plan was implanted in 16 hips (SU group). Significant differences were seen between the SU and SS groups in flexion angle, varus angle, and canal flare index (P<0.05, Table 2). Extension or varus of the stem, or an increase in canal flare index, were risk factors for the used stem size being smaller than planned. On the latest follow-up X-rays, all 124 hips showed bone ingrown stability of the implants. Conclusion. The accuracy of implant size selection was 94.4% and 85.5% for the cup and stem, respectively. No factors associated with cup size mismatch were identified. Flexion angle, varus angle, and canal flare index were associated with stem size mismatch between preoperative planning and the actual used size

Introduction. Female gender, old age (men >60y and women > 55y), severe acetabular dysplasia, poor proximal femoral bone geometry, large (>1cm) femoral head cysts, limb-length discrepancy (> 2cm) and small prosthetic head size (less than 50mm for men and less than 46mm for women) are risk factors for hip resurfacing arthroplasty (HRA). Purpose. To present clinical and radiographic results of HRA in patients having risk factors. Patients and methods: A total of 39 HRA was inserted in 33 patients (11 men and 22 women). Birmingham hip resurfacing (Smith & Nephew, UK) was used in 9 hips and Adept (Finsbury, UK) was used in 30 hips. Among the 30 hips inserted Adept, 11 cups were fixed with rim screws. The mean age of the patients at the time of operation was 52 years. The mean weight and height of the male and female patients were 70.4kg and 167cm, 58.5kg and 154.4cm, respectively. The median head size of the male and female patients was 50mm and 42mm, respectively. Preoperative diagnosis was primary osteoarthritis in 6 hips and secondary osteoarthritis due to aceatbular dysplasia (DDH) in 33 hips. Risk factors of HRA were listed for each patient. The Harris hip score and visual analogue pain scale (VAS) were measures of clinical outcome. Radiographic review was performed retrospectively. MRI and CT images were acquired in 29 hips and 2 hips, respectively, at a mean of 4.8 years after HRA to find periprosthetic soft tissue abnormality such as a psedotumor. Kaplan-Meier method was used to calculate implant survivorship. Results. Two hips had no risk factor, whereas 37 hips had at least one risk factor. Risk factors were listed as follows: female gender in 27, old age in nine, severe acetabular dysplasia in 25, poor proximal femoral bone geometry in 11, head cysts in 13, limb-length discrepancy in three and small head size in 21. There were two revisions in two men. One hip was revised because of acute infection. The patient had a risk factor (old age). Another hip was revised because of cup loosening. The patient had two risk factors (severe acetabular dysplasia and small head size). The mean follow-up period for unrevised hips was 5 years (range, 2 to 8 years). The Harris hip score improved from 47.3 points preoperatively to 96.5 points at the latest follow-up (p<0.001). VAS improved from 65 preoperatively to 5 at the latest follow-up (p<0.001). Using revision for any reason as the endpoint, the Kaplan-Meier survivorship was 94.9% at 5years. No implant was loose at the latest radiographic examination. MRI and CT of the hip revealed no pseudotumor. Discussion. In this series, only two patients had no risk factor for HRA. Although majority of our patients were women with acetabular dysplasia and small head size, clinical and radiographic results of HRA were good up to five years (Figs 1 and 2: pre- and post-operative X-ray of 49y women having five risk factors). Conclusion. Clinical and radiographic results of HRA were good in patients who have risk factors

Introduction: Osseointegration is known to occur around the uncemented acetabular cups which results in fill-in of peri-acetabular gaps. The objective of this study was to assess the gaps around uncemented acetabular cups radiologically in early post-operative period. Methods: 53 primary uncemented total hip arthroplasties were performed at our hospital by a single surgeon between February 2003 and august 2005. There were 29 females and 22 males. Two patients had bilateral surgeries. Mean age of patients was 70 years (range, 52–88 years). Primary osteoarthritis of the hip was the indication for surgery in all the patients. Peri-acetabular gaps were measured on the radiographs taken at day-1 post-operatively and at 3 months follow-up. All the measurements were taken independently by two investigators on two different occasions using a picture archiving & communications (PACS) system. The two sets of data from each investigator were compared for intra and inter-observer variability using independent-samples t test. Results: in 24 cases, no gaps were found around the ace-tabular cups on day-1 post-operative radiographs. In 29 cases, the mean gap was 4 mm (range, 1–8 mm) on postoperative day-1. Five gaps were in zone one, 24 in zone two and none in zone three. At 3 months follow-up, the mean gap was found to be 0.6 mm (range, 0–3 mm). The reduction in gaps from day-1 post-op to 3 months follow-up was statistically significant (chi square test, p< 0.05). Discussion: We found a significant reduction in peri-acetabular gaps as early as at 3 months following uncemented total hip arthroplasties. We feel that settling of the cup within the acetabulum is responsible, rather than osseointegration, for these fill-in of gaps in early postoperative period. A larger study is required to analyse this phenomenon as screws fixation of uncemented cups may compromise their settling within the acetabulum

INTRODUCTION: Metal-on-metal alloarthroplasty of the hip is gaining popularity in order to avoid complications associated with polyethylene wear. On the other hand, metal-on-metal articulations release metal ions, the biological effects of which remain unclear. Genetic and immunological changes have been associated with increased metal ion levels in arthroplasty patients. We intended to study the outcome after metal-on-metal arthroplasty of the hip with a focus on the toxicologically and immunologically relevant metal ions chromium, cobalt, nickel, and manganese. PATIENTS AND METHODS: A prospective, randomised study was designed where all patients received a cemented arthroplasty of the hip, either with a metal-on-metal bearing (Metasul ®; 28 patients) or with a metal-on-polyethylene bearing (Protasul ®, 26 patients). Only patients with primary osteoarthritis of the hip and without other metallic implants were included (mean age 65 years, range 45–74). Follow-up was performed after a minimum of two years. Clinical outcome was measured by the Harris hip score and the SF36, and radiographic analysis was undertaken by plain radiography. Metal ion concentrations in patient serum were analysed by high-resolution plasma mass spectrometry. RESULTS: It was found that the clinical outcome was almost identical in both groups with respect to Harris hip score and SF36, and radiographic signs of osteolyses or loosening did not occur in any group. In the metal-on-metal group, chromium concentrations increased 4.1 fold and cobalt concentrations increased 7.6 fold when compared to preoperative values (p< 0.05; Wilcoxon Mann Whitney Test), whereas nickel and manganese concentrations did not change significantly. In the metal-on-polyethylene group, no significant increase in the concentration of any ion occurred. DISCUSSION: In conclusion, metal-on-metal and metal-on-polyethylene arthroplasties of the hip provide equal clinical and radiographic outcomes in the medium term, but the concentrations of chromium and cobalt increase considerably after metal-on-metal arthroplasty. Importantly, the allergogenic and previously not assessed ions nickel and manganese show no significant changes in the medium term after any type of hip alloarthroplasty. To our knowledge, this is the first study that addresses manganese and nickel concentrations in a prospective, randomized setting, and our patients will be followed further with respect to possible immunological and genetic changes

Background: Recent studies have shown that local infiltration analgesia (LIA) improves outcome after total hip replacement (THA). No detailed information does exist to its influence on length of stay (LOS) after surgery. In this study we have evaluated LOS, pain treatment, mobilization, postoperative nausea and vomiting (PONV) and satisfaction in a period before and after implementing LIA in our department. Patients and Methods: Patients diagnosed with primary osteoarthrosis of the hip scheduled for unilateral uncemented or hybrid THA were included in the study. All cases were recognized from a local database with prospective collected data on all patients undergoing THA in our department. Total 100 consecutive patients who did not have LIA from September 1st 2006 were compared with 100 consecutive patients who received LIA from September 1st 2007. The two groups were unmatched and no patients were excluded. The solution used for LIA consisted of 200 mg Ropivacain, 30 mg Ketorolac and 1 mg Adrenaline dissolved in 100 ml isotone NaCl. Results: Patients in the two groups were similar in regard to gender, age, body mass index (BMI) and ASA group, but did differ in duration of the surgical approach, the latter group having treatment with LIA in average had a 20 minuts shorter surgical approach. The patients who received LIA had reduced LOS, mean 3.8 days compared to 5.1 days in the gropu not treated with LIA (p< 0.001). Moreover, patients treated with LIA were significant more satisfied (p< 0.05) compared to the group who did not receive LIA. Moreover, patients treated with LIA were more frequently mobilized on day 1 after surgery (p< 0,001) and day 3 as well (p< 0.05). Also, patients treated with LIA had significantly reduced PONV on the day of operation (p< 0.05) and well as they consumed more nutrition (p< 0.001) the day after the operation. There was no difference in pain-score between the two groups except on day 3 (p< 0.05) in activity and at rest on the day of discharge (p< 0.05). No wound complications could be shown in any of the groups during the first 6 weeks after surgery. Interpretation: Introducing LIA in our department changed the postoperative period detailed in several ways for patients undergoing THA. This study document that operative wound infiltration with multimodal drugs reduced LOS after THA, even though the reduced duration of operation may be some of the explanation. Moreover, LIA resulted in better mobilisation, less PONV and more satisfied patients. We recommend all unit undertaking THA to implement LIA in their daily praxis

Introduction. Preoperative planning is an essential procedure for successful total hip arthroplasty. Many studies reported lower accuracy of two-dimensional analogue or digital templating for developmentally dysplastic hips (DDH). There have been few studies regarding the utility of three-dimensional (3D) templating for DDH. The aim of the present study is to assess the accuracy and reliability of 3D templating of cementless THA for hip dysplasia. Methods. We used 86 sets of 3D-CT data of 84 patients who underwent consecutive cementless THA using an anatomical stem and a rim-enlarged cup. There were six men and 78 women with the mean age of 58 years. The diagnosis was developmental dysplasia in 70 hips and osteonecrosis in 14 hips and primary osteoarthritis in 2 hips. There were 53 hips in Crowe group I, 11 hips in Crowe group II and 6 hips in Crowe group III. Each operator performed 3D templating prior surgery using a planning workstation of CT-based navigation system. Planned-versus-achieved accuracy was evaluated. The templating results were categorized as either exact size or +/− 1 size of implanted size. To assess the intra- and inter-planner reliabilities, 3D templating was performed by two authors blinded to surgery twice at an interval of one month. Kappa values were calculated. The accuracy and the intra- and inter-planner reliabilities were compared between the DDH group (70 hips) and the non DDH group (16 hips). Results. There was no significant difference in accuracy of component sizes between the DDH group and the non-DDH group. The accuracy of templating for cup sizes was 76 % for DDH and 75 % for non-DDH group (p=0.95). If accuracy was expanded to include all cups within one size of the implanted size, the accuracy was 97 % and 94 %, respectively (p=0.51). The accuracy of templating for stem sizes was 60 % for the DDH group and 75 % for the non-DDH group (p=0.27). The accuracy within 1 size was 99 % and 94 %, respectively (p=0.25). Regarding intra-planner reliability, mean kappa value for the cup size was 0.67 in the DDH group and 0.81 for the non-DDH group (p=0.18). Mean kappa value for the stem size was 0.64 in the DDH group and 0.79 for the non-DDH group (p=0.18). There were no significant differences in intra-planner reliability between the DDH and non-DDH group. Regarding inter-planner reliability for the cup size, mean kappa value was 0.33 in the DDH group and 0.37 in the non-DDH group (p=0.14). Mean kappa value for the stem size was 0.46 in the DDH group and 0.69 in the non-DDH group (p=0.07). There were no significant differences in inter-planner reliability between the DDH and non-DDH group. Conclusion. The 3D templating for cementless THA was accurate for hip dysplasia. Intra- and inter-planner reliabilities of the 3D templating were comparable with those of other primary diagnosis, while intra-planner reliability of cup sizes was fair regardless of diagnosis

We have developed a comprehensive system of assessment of patients undergoing total hip and total knee replacement. This new unified scoring system provides a single instrument to measure the disability of patients suffering from primary osteoarthritis of either hip or knee. This instrument will be used to prioritize these patients for a single waiting list and it will be used as an outcome measure to assess their progress after their hip or knee replacement surgery. The scoring system is comprised of two parts carrying equal point value. The subjective part is an assessment tool completed by the patients themselves. It is comprised of 12 Items covering every aspect of the disability associated with hip and knee arthritis. The objective part is an assessment tool completed by the treating physician or a trained joint arthroplasty nurse. The first stage of this project comprised of formulation of a preliminary questionnaire after a thorough assessment of 50 patients suffering from hip or knee arthritis. We then organised multiple clinical sessions with focus groups to critically appraise the content of our new questionnaire. The focus group patients were invited to give their comments about any issues not discussed previously. This preliminary questionnaire was then converted into a set of closed questions and was divided into a subjective and an objective part. The second stage of this project involved assignment of scales and scale grading for different components of the objective part. This involved the process of magnitude estimation. 75 patients, 25 consultants and 5 nurses were involved in this process. The third stage of this project involved a comprehensive assessment of this new scoring system in terms of internal consistency, internal consistency reliability, inter-observer reliability, test-retest reliability, face validity, content validity and construct validity. The process of validation involved comparison of our scoring system with the relevant parts of SF36, Oxford knee score, WOMAC and AIMS. It has also been tested on the first subset of post operative patients to measure its responsiveness. Cronbach’s alpha was used for internal consistency and Pearson’s correlation coefficients were used for different correlation studies. Our new scoring system has shown a very satisfactory internal consistency. The inter-rater agreement and the test-retest reliability data on the first set of 100 patients are very promising as well. The instrument has shown a significant effect size in the first set of post-op patients 4 months after their surgery. Our new scoring system will provide an easy to apply and comprehensive instrument for a need based waiting list for patients undergoing either THR or TKR. It will also be a reliable and sensitive outcome measure to monitor these patients’ progress in the post-operative period

Aims

The primary outcome was investigating differences in wear, as measured by femoral head penetration, between cross-linked vitamin E-diffused polyethylene (vE-PE) and cross-linked polyethylene (XLPE) acetabular component liners and between 32 and 36 mm head sizes at the ten-year follow-up. Secondary outcomes included acetabular component migration and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension questionnaire, 36-Item Short-Form Health Survey, Harris Hip Score, and University of California, Los Angeles Activity Scale (UCLA).

Femoral stems with exchangeable necks are a recent development in hip arthroplasty. They are proposed to be better in restoring offset and leg length while not compromising the fixation in the femoral canal. Few studies have been published on the clinical and functional outcome of modular neck hip system. The Australian Joint registry data was analysed to evaluate the outcome after modular neck hip arthroplasties with the diagnosis of primary osteoarthritis. Only prostheses with data for more than 50 patients were studied. The indications for revision were identified. A comparison of outcomes with conventional hip arthroplasties was done. The analysis confirmed that femoral stems with exchangeable necks have a significantly higher risk of revision compared to all other primary total conventional hip replacement (adj HR=2.13; 95% CI (1.88, 2.42), p<0.001). With the exception of three, all femoral stems with exchangeable necks have a higher rate of revision compared to primary total conventional hip replacement. The three exceptions have a short follow up. There is an increased incidence of revision for loosening and dislocation. The recent registry data suggests that with end point being revision, the outcome of exchangeable neck hips are worse than conventional hips in patients with primary osteoarthritis of hip

Introduction. Dislocation is one of the most important complications after primary total hip replacement (THR). The low incidence of this finding makes it difficult to analyse the possible risk factors. The surgical technique can also influence this rate through cup position or an adequate reconstruction of the hip. We assessed the demographic data and radiological reconstruction of the hip related to the appearance of dislocation after primary THR. Material and Methods. 1414 uncemented THRs were recorded from our Local Joint Registry. The mean age of the patients was 60.1 years old (range, 14 to 95), and the mean weight was 73.3 kg (42 to 121). There were 733 men and 974 patients were classified with an activity level of 4 or 5 according to Devane. The most frequent diagnosis was primary osteoarthritis, 795 hips, followed by avascular necrosis 207 hips. An alumina-on-alumina THR was implanted in 703 hips and a metal-on-polyethylene THR in 711 hips. A femoral head size of 28 mm was used in 708 hips and 32 mm in 704. Radiological cup position was assessed using the acetabular abduction angle, the height of the center of the hip, and the horizontal distance of the cup. Cup anteversion was measured according to Widmer and the reconstruction of the center of rotation of the hip according to Ranawat. The radiographic reconstruction of the abductor mechanism was measured using two variables: the lever arm and the height of the greater trochanter. Results. There were 38 dislocations (2.6%) and 11 hips were revised for recurrent instability (0.8%). The probability of not having a dislocation at 20 years was 97.3%. 22 hips that had dislocated were within a box for a cup position of a version between 10º to 25º and an acetabular abduction angle between 35º to 55º (p<0.001). The probability of not having a dislocation at 20 years was 98.48% for the cups within the box and 93.9% for cups outside the box (p<0.001, Log Rank test). 21 hips that had dislocated were within a box for a height of the greater trochanter between −2 mm to 5 mm and a lever arm between 56 to 64 mm (p<0.001). The probability of not having a dislocation at 20 years was 98.33% for the hips within the box and 94.6% for hips outside the box (p<0.001, Log Rank test). Adjusted Cox regression analysis showed that alumina-on alumina THR tended to dislocate less than metal-on-polyethylene THRs (p=0.061, Hazard Ratio: 2.238, Confidence Interval 95% 0.964–5.195), and hips outside the box evaluated for cup position and outside the lever arm and height of the greater trochanter box) had a higher risk for dislocation (p<0.001, HR: 3.418, CI 95% 1.784–6.549, and, p<0.001, HR:2.613, CI 95% 1.357–5.032, respectively). Conclusions. A proper reconstruction of the hip is essential to decrease the risk for dislocation after primary THR. The choice of the bearing surface may affect this risk. The weakness of the abductor muscles of the hip may be one of the most important causes for dislocation

Patients who are less than 50 years old at the time of total hip arthroplasty (THA) have been known to have higher failure rates than patients who are older. Wearinduced osteolysis and associated component loosening is the most common mode of failure reported. The current investigation prospectively assessed the survivorship and clinical results of alumina ceramic-ceramic THA in patients younger than 50 years. 238 consecutive hips in 201 patients treated by alumina ceramic-ceramic THA were studied. The mean age at operation was 41.4 ± 7.5 years (range, 18 – 50 years). The preoperative Merle d’Aubigné score was 11.1 ± 1.6 (6 – 15). The preoperative diagnosis included primary osteoarthritis or impingement (105 hips, 44%), developmental dysplasia of the hip (90 hips, 38%), osteonecrosis of the femoral head (17 hips, 7%), post-traumatic osteoarthrosis (16 hips, 7%), and rheumatoid arthritis (6 hip, 3%). 144 hips (61%) were replaced with the use of surgical navigation for acetabular component positioning. The mean cup diameter was 51.8 ± 3.7 (range, 46 – 60 mm). 73 (31%) bearings were 28 mm and 165 (69%) bearings were 32 mm. At mean follow-up of 5.6 ± 2.3 years (2 – 11 years), the mean Merle d’Aubigné score was 17.4 ± 0.9 (14 – 18). There were no radiographic signs of osteolysis. There were two revisions (0.8%): one for acute cup displacement and one for a ceramic liner fracture. In addition, one hip was treated by I& D for acute infection and another with I& D but without evidence of infection. Other complications included one greater trochanter fracture and one calcar fracture, both repaired at surgery, and one transient peroneal nerve palsy. The 10-year Kaplan Meier survivorship of the implants (revision of any component for any reason) was 98.7% (95% confidence interval 96.3–100%). There were no hip dislocations. Results of THA in patients less than 50 years using alumina ceramic-ceramic bearings at two to eleven years follow-up are promising with no case of osteolysis or dislocation

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

In recent years advances in operative techniques have allowed surgeons to perform total hip arthroplasty (THA) through incisions much smaller than those used previously. Potential advantages of these techniques include the reduction of blood loss and pain in the immediate postoperative period and preserving muscle function. Potential disadvantages might include increased wound infection rate due to skin ischemia, intraoperative neurovascular injuries, and component malposition. This in turn may lead to long term complications, such as instability, osteolysis, and loosening. The purpose of this study is to present our results with total hip arthroplasty performed through a minimal invasive technique which is a modification of the standard posterolateral approach. Methods: In this retrospective study 91 consecutive patients underwent primary total hip arthroplasties were reviewed. The surgeries were performed at our institution from January 2001 to December 2003. Surgical indications included primary osteoarthritis, subcapital fractures, malignancy, hip displasia, Otopelvis, rheumatoid arthritis and AVN. Exclusion criteria included revision hip arthroplasty, and cemented operations. A modification of the standard posterlateral approach was used. Standard hip arthroplasty instruments along with curved acetabular reamers and impactor were used. Incision extent was determined by the size of the acetabular component. A fully Hidroxyapetite coated stem, and porous coated acetabullar component were used. Immediate full weight bearing postoperative regimen was allowed in all cases. Results: In 17 patients (group A) the indication for surgery was a recent subcapital fracture. 74 patients (group B) had no trauma. The average age was 64.2 in group A and 65.1 in group B. No case of deep infection was documented in either group. 5 patients in group B had a single event of a posterior dislocation that was treated successfully with closed reduction. No dislocation occurred in group A. 35% (4) of group A and 41% (22) of group B did not require postoperative blood transfusions. 47% (6) and 36% (14) respectively needed transfusion of 3 blood units or more. Average hospitalization time was 6 days. None of the patients in both groups needed re-operation. Conclusions: Minimally invasive total hip arthroplasty is associated with a short hospitalization period and relatively low rate of blood transfusion. No major wound healing problems were documented in our series. It appears that the relatively high dislocation rate might be explained partly due to the common use of ceramic inserts. Further modification of the technique for proper acetabular component orientation is needed. However, more prospective with longer follow-up research must be conducted before definitive recommendations can be made