INTRODUCTION

Femoral neck narrowing (NN) following Metal-on-Metal Hip Resurfacing Arthroplasty (MoMHRA) is a well-recognised clinical phenomenon. The incidence of resurfaced hips with NN > 10% is reported to be up to 27%. Its pathogenesis is thought to be multi-factorial secondary to stress shielding, impingement, osteolysis secondary to wear/ion particles and as a result of reduced vascularity and pressure effect on cancellous bone secondary to the presence of a soft-tissue mass around the resurfaced hip. Recognised risk factors for its development include: female gender and the presence of a pseudotumour. Serum Chromium (Cr) and Cobalt (Co) are recognised surrogate markers of in-vivo wear of MoMHRA. The aims of this study were to establish whether NN is associated with increased wear.

The purpose of the study is to evaluate the retrospective results of 92 surgically treated spastic hips. Twenty-one patients were able to walk in the community with aids, 19 were able to walk about the house, and 13 were wheelchair bound. The mean age at the time of the operation was 7 yrs (3–18) and the average follow-up was 5. The cohort of the study included 45 tetraplegic patients, 6 diplegic, and 2 hemiplegic. The dislocated hips were 25 and the subluxated ones 67.

The surgical treatment included soft tissue and bone procedures. The 53 patients were divided into two age groups: those less than 7yrs old and those older than 7yrs. The cohort was also divided into 39 patients operated in one setting, and 14 operated in more than one. Clinical evaluation was based on the joint range of motion, the ambulatory status and the pain. The radiological evaluation criteria were based on Reimer's migration index, the center-edge angle, Sharp's angle, and neck-femoral angle. We used the interclass correlation coefficient to measure our interobserver reliability for MI 0,93, for CE angle 0,95 and for Sharp's angle 0,81, as the interobserver difference for MI averaged 9% for CE angle 7and for Sharp's angle 3.

Statistical analysis of continuous variables was done by Student's t-test or the Wilcoxon rank sum test. Categorical variables were evaluated by Fisher's test. Concerning the walking ability, from the 13 severe quadriplegic patients, none improved his functional level but they achieved better sitting balance. The walking ability of the rest of the patients improved one level in 78% of the cases. The mean preoperative abduction was improved from 24,7 to 33,5, the mean flexion was slightly reduced from 123 preoperatively to 114 postoperatively and the mean extension reduced from −20 preoperatively to −8 postoperatively. Reimer's index reduced from 67,2 to 21,7 postoperatively, the CE angle increased from −10,6 to 20,5, the Sharp's angle increased from 36,9 to 40,5 and the neck-shaft angle increased from 119,7 to 157,5post-operatively. Of greater significance were MI and CE at p<0.05. A migration index of >50% at final follow-up was associated with a worse migration index and a worse CE angle at 1 year post-operatively. 46 hips were evaluated as good, 30 as satisfactory, and 16 as poor. The severe tetraplegic with small-negative CE angle and Reimer's migration index > 50%, as well as the small age of the patients (<7 yrs) were negative prognostic factors. Better results were observed when patients were operated at age <7yrs by soft tissue procedures and MI<30%, while patients >7yrs had satisfactory results only after combined bony and soft tissue procedures and MI <50%. A migration index of >50% at final follow-up was associated with a worse migration index and a worse CE angle at 1 year postoperatively.

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.

Aims

The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population.

Traumatic hip dislocation is a rare injury in orthopaedic practice and typically occures in high energy trauma. The goal of this study was to analyze hip morphology in patients with low energy traumatic hip dislocations and to compare it with a control group. We performed a retrospective comparative study. The study group included 45 patients with 45 traumatic posterior hip dislocation. Inclusion criteria were traumatic hip dislocation with simple acetabular rim or Pipkin I or II fracture. Traumatic dislocations combined with other acetabular or femoral fractures were excluded. The control group consisted of 90 patients (180 hips) that underwent radiographic examination for urogenital indication and had no history of hip pain. Hip morphology was assessed on antero-posterior and axial views. The study group showed significantly increased incidence (p<0.001) of positive cross-over sign (82% vs. 27%) with a increased retroversion index (26 ± 17 [0–56] vs. 6 ± 12 [0–53]), positive ischial spine sign (70% vs. 34%), and positive posterior wall sign (79% vs. 21). Hips that underwent an low energy posterior traumatic hip dislocation show significanly more radiographic signs for acetabular retroversion compared to a control group. Therefore, acetabular retroversion seems to be a contributing factor for posterior traumatic hip dislocation

Introduction. Many patients with displaced intracapsular femoral neck fractures (IFNF) are treated with hemiarthroplasty (HA) which has been shown superior to internal fixation(IF) the first year after injury. Long term results, however, are sparse. Methods. A total of 222 consecutive patients above 60 years, including mentally disabled, with IFNF were randomized to either internal fixation with two parallel screws or hemiarthroplasty, and operated by the surgeon on call. After 5 years, 68 of the 70 surviving patients accepted a follow-up visit. The reviewers were blinded for initial treatment. Results. The mean survival of the groups was similar. Only 12 (of 31) patients in the IF group still had their native hip joint at five years. Harris Hips score was 70.0 ± 3.5 and 70.4 ± 3.4 in the IF and hemiarthroplasty group, respectively (p=0.9). Eq5d index was in the IF group 0.56 ±0.08 and in the hemiarthroplasty group 0.45 ± 0.7 (p=0.3). Barthel ADL index was split into good function (score 95 or 100) and reduced function (score below 95). Of the patients in the internal fixation group, 42 % reported good function, corresponding number in the arthroplasty group was 52 % (p=0.4). After two years, there were 44 (42%) hips with a major reoperation in the IF group and 11 (10%) in the hemiarthroplasty group. Between 2 and 5 years, there were two new major reoperations (both in the IF group; avascular necrosis; deep wound infection). Discussion. Hemiarthroplasty has predictable and good long time surgical results. These findings emphasize that arthroplasty is better than IF as treatment for displaced intracapsular femoral neck fractures

The Bernese Periacetabular Osteotomy (PAO) has become the established method for treating developmental dysplasia of the hip. In the 1990s, the surgical technique was modified to avoid postoperative cam impingement due to uncorrected head neck offset or pincer impingement due to acetabular retroversion after reorientation. The goal of the study was to compare the survivorship of two series of PAOs with and without the modifications of the surgical technique and to calculate predictive factors for a poor outcome. A retrospective, comparative study of two consecutive series of PAOs with a minimum follow-up of 10 years was carried out. Series A included 75 PAOs performed between 1984 and 1987 and represent the first cases of PAO. Series B included 90 hips that underwent PAO between 1997 and 2000. In this series, emphasis was put on an optimal acetabular version next to the correction of the lateral coverage. Additionally, a concomitant arthrotomy was performed in every hip to check impingement-free range of motion after reorientation and in 50 hips (56%) an additional offset correction was performed. Survivorship analyses according to Kaplan and Meier were carried out and the endpoint was defined as conversion to a total hip arthroplasty, progression of osteoarthritis, or a Merle d'Aubign score 14. Predictive factors for poor outcome were calculated using the Cox-regression analysis. The cumulative 10-year survivorship of Series A was significantly decreased (77%; 95%-confidence interval [CI] 72–82%) compared to Series B (86%; 95%-CI 82–89%, p=0.005). Hips with an aspherical head showed a significantly increased survivorship if a concomitant offset correction was performed intraoperatively (90% [95%-CI 86–94%] versus 77% [95%-CI 71–82%], p=0.003). Preoperative factors predicting poor outcome included a high age at surgery, a Merle d'Aubign score 14, a positive impingement test, a positive Trendelenburg sign, limp, an increased grade of osteoarthritis according to Tönnis, and (sub-) luxation of the femoral head (Severin > 3). In addition, predictive factors related to the three dimensional orientation of the acetabular fragment were identified. These included total, anterior, and posterior acetabular over-coverage or under-coverage, acetabular retroversion or excessive anteversion, a lateral center edge angle < 22 °, an acetabular index > 14 °, and no offset correction in aspherical femoral heads. A good long term result after PAO mainly depends on optimal three-dimensional orientation of the acetabulum and impingement-free range of motion with correction of an aspherical head neck junction if necessary

Introduction. Ectopic ossification (EO) at the acetabular rim has been suggested to be associated with pincer impingement and to lead to ossification of the labrum. However, this has never been substantiated with histological, radiographic and MRI findings in large cohorts of patients. We hypothesized that it is more a bone apposition of the acetabular rim and that it occurs more frequently in coxa profunda (CP) hips. Materials and Methods. In the first part, a cohort of 20 hips with this suspected ectopic rim ossification (EO) pattern were identified. The radiographic features that could be associated with this ossification pattern were described and evaluated by a histologic examination of intra-operative samples taken from the rim trimming. In the second part, we assessed the prevalence of this ectopic ossification process in a cohort of 203 patients treated for FAI. Results. Histologic examination revealed that new acetabular bone formation was either overgrowing the non-ossified labrum or moving it away from the native rim. Radiologically, this was associated with an “indentation sign” and/or a “double line sign”. There were no specimens that had shown any evidence of labral ossification. EO was found in 26 hips (18%) of the second cohort. Twenty of 26 hips (77%) with EO had CP morphology and 29% of CP hips had EO signs. In contrast, only 6 non-profunda hips (8%) were associated with EO. There was a high correlation between XR and MRI findings as >80% of XR findings were confirmed on MRI. Sixty-nine hips had CP morphology. The double line sign (N = 13), the indentation sign (N = 12) and a prominent lateral rim (N = 11) were found. Hips with an EO pattern were found in patients that were significantly older than those without EO (p = 0.01). The acetabular characteristics of the EO groups were not significantly different from the CP hips without EO. The femoral characteristics were significantly different between groups with lower neck shaft angles (128° vs 134°;p = 0,0002) and shorter femoral necks lengths (62mm vs 65mm; p = 0,04)) in the EO group. The mean Tonnis classification was not significantly different (p = 0,18). In addition, the mean acetabular cartilage degeneration status was not different between both groups (p = 0,9). Rim trimming down to the native acetabular bone was done in all cases either by arthroscopy (N = 40) or open surgical dislocation (N = 17). Discussion. Ectopic ossification of the acetabular rim predominantly occurs in CP and is associated with specific anatomic features of the proximal femur. This type of impingement seems to be different and less aggressive than other described impingement processes. The double line sign and indentation sign are highly indicative for this EO process and are indicative for a longstanding impingement problem. Trimming of the acetabular rim should be conducted

Aims

The aims of this study were to determine the cumulative ten-year survivorship of hips treated for acetabular fractures using surgical hip dislocation and to identify factors predictive of an unfavourable outcome.