Aims

We investigated changes in the axial alignment of the ipsilateral hip and knee after total hip arthroplasty (THA).

Aims

We present an audit comparing our level I major trauma centre’s data for a cohort of patients with hip fractures in the National Hip Fracture Database (NHFD) with locally held data on these patients.

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A delay in establishing the diagnosis of an occult fracture of the hip that remains unrecognised after plain radiography can result in more complex treatment such as an arthroplasty being required. This might be avoided by earlier diagnosis using MRI. The aim of this study was to investigate the best MR imaging sequence for diagnosing such fractures. From a consecutive cohort of 771 patients admitted between 2003 and 2011 with a clinically suspected fracture of the hip, we retrospectively reviewed the MRI scans of the 35 patients who had no evidence of a fracture on their plain radiographs. In eight of these patients MR scanning excluded a fracture but the remaining 27 patients had an abnormal scan: one with a fracture of the pubic ramus, and in the other 26 a T₁-weighted coronal MRI showed a hip fracture with 100% sensitivity. T₂-weighted imaging was undertaken in 25 patients, in whom the diagnosis could not be established with this scanning sequence alone, giving a sensitivity of 84.0% for T₂-weighted imaging.

If there is a clinical suspicion of a hip fracture with normal radiographs, T₁-weighted coronal MRI is the best sequence of images for identifying a fracture.

We systematically reviewed the peer-reviewed literature to relate the survival of hybrid metal-on-metal hip resurfacing arthroplasty devices to a National Institute of Clinical Excellence (NICE) benchmark for choosing a primary total hip replacement, which is a survival rate of 90% at a follow-up of ten years.

A total of 29 articles (10 621 resurfaced hips) met the inclusion criteria. The mean follow-up ranged from 0.6 to 10.5 years and the survival of the implant ranged from 84% to 100%. Of the 10 621 hips, 370 were revised (3.5%), with aseptic loosening as the most frequent mode of failure.

None of the hip resurfacing arthroplasty implants used to date met the full ten-year NICE benchmark of survival. A total of 13 studies showed satisfactory survival compared with the three-year NICE benchmark.

The August 2012 Hip & Pelvis Roundup³⁶⁰ looks at: whether cemented hip replacement might be bad for your health; highly cross-linked polyethylene; iHOT-33 - a new hip outcome measure; hamstring injuries; total hip replacement; stemmed metal-on-metal THR; bipolar hemiarthroplasty, neuromuscular disease and dislocation; the high risk of secondary hemiarthroplasty; and whether we have to repair the labrum after all?

We report the survival, radiological and functional outcomes of a single surgeon series of his first 144 consecutive Birmingham hip resurfacing procedures (130 patients) at a minimum of ten years. There were ten revisions during this time. Although no patients were lost to follow-up some did not complete the scoring assessment or undergo radiological assessment at ten years.

The ten-year survival for male patients was 98.0% (95% confidence interval 95.2 to 100). The ten-year survival for the total cohort with aseptic revision as the endpoint was 95.5% (95% confidence interval 91.8 to 99.0) and including revisions for sepsis was 93.5% (95% confidence interval 89.2 to 97.6). The median modified Oxford hip score at ten years was 4.2% (interquartile range 0 to 19) and the median University of California, Los Angeles score was 7.0 (interquartile range 5.0 to 8.0).

This study confirms the midterm reports that metal-on-metal hip resurfacing using the Birmingham Hip provides a durable alternative to total hip replacement, particularly in younger male patients wishing to maintain a high level of function, with low risk of revision for at least ten years.

We undertook a retrospective comparative study of all patients with an unstable slipped capital femoral epiphysis presenting to a single centre between 1998 and 2011. There were 45 patients (46 hips; mean age 12.6 years; 9 to 14); 16 hips underwent intracapsular cuneiform osteotomy and 30 underwent pinning in situ, with varying degrees of serendipitous reduction. No patient in the osteotomy group was lost to follow-up, which was undertaken at a mean of 28 months (11 to 48); four patients in the pinning in situ group were lost to follow-up, which occurred at a mean of 30 months (10 to 50). Avascular necrosis (AVN) occurred in four hips (25%) following osteotomy and in 11 (42%) following pinning in situ. AVN was not seen in five hips for which osteotomy was undertaken > 13 days after presentation. AVN occurred in four of ten (40%) hips undergoing emergency pinning in situ, compared with four of 15 (47%) undergoing non-emergency pinning. The rate of AVN was 67% (four of six) in those undergoing pinning on the second or third day after presentation.

Pinning in situ following complete reduction led to AVN in four out of five cases (80%). In comparison, pinning in situ following incomplete reduction led to AVN in 7 of 21 cases (33%). The rate of development of AVN was significantly higher following pinning in situ with complete reduction than following intracapsular osteotomy (p = 0.048). Complete reduction was more frequent in those treated by emergency pinning and was strongly associated with AVN (p = 0.005).

Non-emergency intracapsular osteotomy may have a protective effect on the epiphyseal vasculature and should be undertaken with a delay of at least two weeks. The place of emergency pinning in situ in these patients needs to be re-evaluated, possibly in favour of an emergency open procedure or delayed intracapsular osteotomy. Non-emergency pinning in situ should be undertaken after a delay of at least five days, with the greatest risk at two and three days after presentation. Intracapsular osteotomy should be undertaken after a delay of at least 14 days. In our experience, closed epiphyseal reduction is harmful.

Cite this article: Bone Joint J 2015;97-B:412–19.

We present the clinical results and survivorship of consecutive 100 Birmingham Hip Resurfacings in 90 patients at a minimum follow-up of ten years. All procedures were carried out by an independent surgeon who commenced a prospective study in 1998. Patients were assessed clinically using the Western Ontario and McMaster Universities osteoarthritis index, Short-Form 36, Harris hip score and University of California, Los Angeles activity score. Radiological analysis was performed by an independent observer and blood metal ion levels concentrations were measured at ten years post-operatively in 62 patients. The median acetabular component inclination was 46.2° (34° to 59°) and anteversion 11.0° (0° to 30°). The median chromium concentration in the unilateral group was 1.74 (0.41 to 15.23) and for the bilateral group was 2.98 (1.57 to 18.01). The equivalent values for cobalt were 1.67 (0.54 to 20.4) and 1.88 (1.38 to 19.32).

In total there were eight failures giving an overall survival at ten years of 92% (95% confidence interval (CI) 86.7 to 97.3). BHR in male patients had an improved survivorship of 94.6% (95% CI 89.4 to 100) compared with females at 84.6% (95% CI 70.7 to 98.5), but this did not reach statistical significance (p = 0.119). Four of the nine BHRs with a bearing diameter of 42 mm failed.

The overall results were consistent with data produced from other centres in that the clinical outcome of large male patients was extremely encouraging, whereas the survival of the smaller joints was less satisfactory.

Several studies have reported the rate of post-operative mortality after the surgical treatment of a fracture of the hip, but few data are available regarding the delayed morbidity. In this prospective study, we identified 568 patients who underwent surgery for a fracture of the hip and who were followed for one year. Multivariate analysis was carried out to identify possible predictors of mortality and morbidity. The 30-day, four-month and one-year rates of mortality were 4.3%, 11.4%, and 18.8%, respectively. General complications and pre-operative comorbidities represented the basic predictors of mortality at any time interval (p < 0.01). In-hospital, four-month and one-year general complications occurred in 29.4%, 18.6% and 6.7% of patients, respectively. After adjusting for confounding variables, comorbidities and poor cognitive status determined the likelihood of early and delayed general complications, respectively (p < 0.001). Operative delay was the main predictor of the length of hospital stay (p < 0.001) and was directly related to in-hospital (p = 0.017) and four-month complications (p = 0.008).

Cite this article: Bone Joint J 2015;97-B:383–90

Degenerative problems of the hip in patients with childhood and adult onset neuromuscular disorders can be challenging to treat. Many orthopaedic surgeons are reluctant to recommend total hip replacement (THR) for patients with underlying neuromuscular disorders due to the perceived increased risks of dislocation, implant loosening, and lack of information about the functional outcomes and potential benefits of these procedures in these patients. Modular femoral components and alternative bearings which facilitate the use of large femoral heads, constrained acetabular components and perhaps more importantly, a better understanding about the complications and outcomes of THR in the patient with neuromuscular disorders, make this option viable. This paper will review the current literature and our experience with THR in the more frequently encountered neuromuscular disorders.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):27–31.

Proximal femoral varus osteotomy improves the biomechanics of the hip and can stimulate normal acetabular development in a dysplastic hip. Medial closing wedge osteotomy remains the most popular technique, but is associated with shortening of the ipsilateral femur.

We produced a trigonometric formula which may be used pre-operatively to predict the resultant leg length discrepancy (LLD). We retrospectively examined the influence of the choice of angle in a closing wedge femoral osteotomy on LLD in 120 patients (135 osteotomies, 53% male, mean age six years, (3 to 21), 96% caucasian) over a 15-year period (1998 to 2013). A total of 16 of these patients were excluded due to under or over varus correction. The patients were divided into three age groups: paediatric (< 10 years), adolescent (10 to 16 years) and adult (> 16 years). When using the same saw blades as in this series, the results indicated that for each 10° of angle of resection the resultant LLD equates approximately to multiples of 4 mm, 8 mm and 12 mm in the three age groups, respectively.

Statistical testing of the 59 patients who had a complete set of pre- and post-operative standing long leg radiographs, revealed a Pearson’s correlation coefficient for predicted versus radiologically observed shortening when using a wedge of either 10° or 20° of 0.93 (p <  0.001). The 95% limits of agreement from the Bland–Altman analysis for this subgroup were –3.5 mm to +3.3 mm. It has been accepted that a 10 mm discrepancy is clinically acceptable.

This study identified a geometric model that provided satisfactory accuracy when using specific saw blades of known thicknesses for this formula to be used in clinical practice.

Cite this article: Bone Joint J 2014;96-B:1124–9

We report a 12- to 15-year implant survival assessment of a prospective single-surgeon series of Birmingham Hip Resurfacings (BHRs). The earliest 1000 consecutive BHRs including 288 women (335 hips) and 598 men (665 hips) of all ages and diagnoses with no exclusions were prospectively followed-up with postal questionnaires, of whom the first 402 BHRs (350 patients) also had clinical and radiological review.

Mean follow-up was 13.7 years (12.3 to 15.3). In total, 59 patients (68 hips) died 0.7 to 12.6 years following surgery from unrelated causes. There were 38 revisions, 0.1 to 13.9 years (median 8.7) following operation, including 17 femoral failures (1.7%) and seven each of infections, soft-tissue reactions and other causes. With revision for any reason as the end-point Kaplan–Meier survival analysis showed 97.4% (95% confidence interval (CI) 96.9 to 97.9) and 95.8% (95% CI 95.1 to 96.5) survival at ten and 15 years, respectively. Radiological assessment showed 11 (3.5%) femoral and 13 (4.1%) acetabular radiolucencies which were not deemed failures and one radiological femoral failure (0.3%).

Our study shows that the performance of the BHR continues to be good at 12- to 15-year follow-up. Men have better implant survival (98.0%; 95% CI 97.4 to 98.6) at 15 years than women (91.5%; 95% CI 89.8 to 93.2), and women < 60 years (90.5%; 95% CI 88.3 to 92.7) fare worse than others. Hip dysplasia and osteonecrosis are risk factors for failure. Patients under 50 years with osteoarthritis fare best (99.4%; 95% CI 98.8 to 100 survival at 15 years), with no failures in men in this group.

Cite this article: Bone Joint J 2014;96-B:1298–1306.

The June 2012 Hip & Pelvis Roundup³⁶⁰ looks at: whether metal-on-metal is really such a disaster; resurfacings with unexplained pain; large heads and high ion levels; hip arthroscopy for FAI; the inaccuracy of clinical tests for impingement; arthroscopic lengthening of iliopsoas; the OA hip; the injured hamstring – football’s most common injury; an algorithm for hip fracture surgery; and sparing piriformis at THR.

The presence of pseudotumours, which are soft-tissue masses relating to the hip, after metal-on-metal hip resurfacing arthroplasty has been associated with elevated levels of metal ions in serum, suggesting that pseudotumours occur when there is increased wear. We aimed to quantify the wear in vivo of implants revised for pseudotumours (eight) and of a control group of implants (22) revised for other reasons of failure.

We found that the implant group with pseudotumours had a significantly higher rate of median linear wear of the femoral component at 8.1 μm/year (2.75 to 25.4) than the 1.79 μm/year (0.82 to 4.15; p = 0.002) of the non-pseudotumour group. For the acetabular component a significantly higher rate of median linear wear of 7.36 μm/year (1.61 to 24.9) was observed in the pseudotumour group compared with 1.28 μm/year (0.81 to 3.33, p = 0.001) in the other group. Wear of the acetabular component in the pseudotumour group always involved the edge of the implant, indicating that edge-loading had occurred.

Our findings are the first direct evidence that pseudotumour is associated with increased wear at the metal-on-metal articulation. Furthermore, edge-loading with the loss of fluid-film lubrication may be an important mechanism of generation of wear in patients with a pseudotumour.

The purpose of this study was twofold: first, to determine whether the five-year results of hip resurfacing arthroplasty (HRA) in Canada justified the continued use of HRA; and second, to identify whether greater refinement of patient selection was warranted.

This was a retrospective cohort study that involved a review of 2773 HRAs performed between January 2001 and December 2008 at 11 Canadian centres. Cox’s proportional hazards models were used to analyse the predictors of failure of HRA. Kaplan–Meier survival analysis was performed to predict the cumulative survival rate at five years. The factors analysed included age, gender, body mass index, pre-operative hip pathology, surgeon’s experience, surgical approach, implant sizes and implant types. The most common modes of failure were also analysed.

The 2773 HRAs were undertaken in 2450 patients: 2127 in men and 646 in women. The mean age at operation was 50.5 years (sd 8.72; 18 to 82) and mean follow-up was 3.4 years (sd 2.1; 2.0 to 10.1). At the last follow-up a total of 101 HRAs (3.6%) required revision. Using revision for all causes of failure as the endpoint, Kaplan–Meier survival analysis showed a cumulative survival of 96.4% (95% confidence interval (CI) 96.1 to 96.9) at five years. With regard to gender, the five-year overall survival was 97.4% in men (95% CI 97.1 to 97.7) and 93.6% in women (95% CI 92.6 to 94.6). Female gender, smaller femoral components, specific implant types and a diagnosis of childhood hip problems were associated with higher rates of failure. The most common cause of failure was fracture of the femoral neck, followed by loosening of the femoral component.

The failure rates of HRA at five years justify the ongoing use of this technique in men. Female gender is an independent predictor of failure, and a higher failure rate at five years in women leads the authors to recommend this technique only in exceptional circumstances for women.

Cite this article: Bone Joint J 2013;95-B:1044–50.