The cause of fracture of the femoral neck after hip resurfacing is poorly understood. In order to evaluate the role of avascular necrosis we compared 19 femoral heads retrieved at revision for fracture of the femoral neck and 13 retrieved for other reasons. We developed a new technique of assessing avascular necrosis in the femoral head by determining the percentage of empty osteocyte lacunae present. Femoral heads retrieved as controls at total hip replacement for osteoarthritis and avascular necrosis had 9% (. sd. 4; n = 13) and 85% (. sd. 5; n = 10, p < 0.001) empty lacunae, respectively. In the fracture group the percentage of empty lacunae was 71% (. sd. 22); in the other group it was 21% (. sd. 13). The differences between the groups were highly significant (p < 0.001). We conclude that fracture after resurfacing of the hip is associated with a significantly greater percentage of empty osteocyte lacunae within the trabecular bone. This indicates established avascular necrosis and suggests that damage to the blood supply at the time of surgery is a potent risk factor for fracture of the femoral neck after hip resurfacing

The use of bisphosphonates in the treatment of avascular necrosis of the femoral head is an encouraging but relatively new option with most published data being derived from small trials with limited follow-up. We present a clinicoradiological analysis of 395 hips with avascular necrosis which were treated with oral alendronate for three years with a mean follow-up of four years (1 to 8). Our results show an improvement in the clinical function, a reduction in the rate of collapse and a decrease in the requirement for total hip replacement, compared with the findings of other studies in which no treatment was given. This improvement is particularly marked if the treatment is begun in the pre-collapse stages of the disease. Even in Ficat stage-III hips some benefit was obtained from treatment with alendronate by at least a delay in the need for total hip replacement

We performed 96 Birmingham resurfacing arthroplasties of the hip in 71 consecutive patients with avascular necrosis of the femoral head. A modified neck-capsule-preserving approach was used which is described in detail. The University of California, Los Angeles outcome score, the radiological parameters and survival rates were assessed. The mean follow-up was for 5.4 years (4.0 to 8.1). All the patients remained active with a mean University of California, Los Angeles activity score of 6.86 (6 to 9). Three hips failed, giving a cumulative survival rate of 95.4%. With failure of the femoral component as the endpoint, the cumulative survival rate was 98.0%. We also describe the combined abduction-valgus angle of the bearing couple, which is the sum of the inclination angle of the acetabular component and the stem-shaft angle, as an index of the optimum positioning of the components in the coronal plane. Using a modified surgical technique, it is possible to preserve the femoral head in avascular necrosis by performing hip resurfacing in patients with good results

This retrospective study describes the long-term results of core decompression and placement of a non-vascularised bone graft in the management of avascular necrosis of the femoral head. We treated 80 hips in 65 patients, 18 by a cortical tibial autograft and 62 by a fibular allograft. The mean age of the patients was 36 years (. sd. 13.2). A total of 78 hips were available for evaluation of which pre-operatively six were Ficat-Arlet stage 0, three stage I, 31 stage IIA, 16 stage IIB, 13 stage III and nine stage IV. A total of 34 hips (44%) were revised at a mean of four years (. sd. 3.8). Survivorship analysis using a clinical end-point showed a survival rate of 59% five years after surgery. We found a significant difference (p = 0.002) in survivorship, when using a clinical and radiological end-point, between the two grafts, in favour of the tibial autograft. We considered this difference to be the result of the better quality and increased volume of tibial bone compared with that from the trochanteric region used with the fibular allograft. This is a relatively simple, extra-articular and reproducible procedure. In our view core decompression, removal of the necrotic tissue and packing of the cancellous grafts into the core track are vital parts of the procedure

We describe the results of 76 total arthroplasties of the hip for stage-III or stage-IV avascular necrosis of the femoral head. Harris Galante Porous cups were used in 63 patients between 1986 and 1994 and followed prospectively. We reviewed 70 hips with a follow-up of more than five years (mean 7.6). At the latest review the mean Harris Hip Score had improved from a preoperative value of 29 ± 14.7 to 94 ± 6.8. Radiologically, there was no evidence of acetabular migration. The rate of revision for the femoral component was 8.6%, three being undertaken for loosening and three to allow downsizing of the femoral head. The rate of revision for the acetabular component was 7.1% (five cups). At the time of revision none of the cups was clinically loose, and only required the liner to be changed. The rate of complications was low with no case of deep infection or dislocation, but nine of the 76 hips (11.8%) showed grade-III heterotopic ossification. Previous studies of patients undergoing cemented total hip arthroplasty for the treatment of advanced avascular necrosis have indicated a high incidence of loosening of the acetabular component. Our findings show good medium-term results using the Harris Galante Porous cup for acetabular reconstruction, together with a variety of cemented femoral components, for the treatment of this difficult problem

Aims. The objective of this study was to investigate bone healing after internal fixation of displaced femoral neck fractures (FNFs) with the Dynamic Locking Blade Plate (DLBP) in a young patient population treated by various orthopaedic (trauma) surgeons. Patients and Methods. We present a multicentre prospective case series with a follow-up of one year. All patients aged ≤ 60 years with a displaced FNF treated with the DLBP between 1st August 2010 and December 2014 were included. Patients with pathological fractures, concomitant fractures of the lower limb, symptomatic arthritis, local infection or inflammation, inadequate local tissue coverage, or any mental or neuromuscular disorder were excluded. Primary outcome measure was failure in fracture healing due to nonunion, avascular necrosis, or implant failure requiring revision surgery. Results. In total, 106 consecutive patients (mean age 52 years, range 23 to 60; 46% (49/106) female) were included. The failure rate was 14 of 106 patients (13.2%, 95% confidence interval (CI) 7.1 to 19.9). Avascular necrosis occurred in 11 patients (10.4%), nonunion in six (5.6%), and loss of fixation in two (1.9%). Conclusion. The rate of fracture healing after DLBP fixation of displaced femoral neck fracture in young patients is promising and warrants further investigation by a randomized trial to compare the performance against other contemporary methods of fixation. Cite this article: Bone Joint J 2018;100-B:443–9

Aims. The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE). However, there is a risk of developing avascular necrosis of the femoral head (AVN). In this paper, we report on clinical outcome, radiological outcome, AVN rate and complications, and the cumulative survivorship at long-term follow-up in patients undergoing the modified Dunn procedure for severe SCFE. Patients and Methods. We performed a retrospective analysis involving 46 hips in 46 patients treated with a modified Dunn procedure for severe SCFE (slip angle > 60°) between 1999 and 2016. At nine-year-follow-up, 40 hips were available for clinical and radiological examination. Mean preoperative age was 13 years, and 14 hips (30%) presented with unstable slips. Mean preoperative slip angle was 64°. Kaplan–Meier survivorship was calculated. Results. At the latest follow-up, the mean Merle d’Aubigné and Postel score was 17 points (14 to 18), mean modified Harris Hip Score was 94 points (66 to 100), and mean Hip Disability and Osteoarthritis Outcome Score was 91 points (67 to 100). Postoperative slip angle was 7° (1° to 16°). One hip (2%) had progression of osteoarthritis (OA). Two hips (5%) developed AVN of the femoral head and required further surgery. Three other hips (7%) underwent implant revision due to screw breakage or change of wires. Cumulative survivorship was 86% at ten-year follow-up. Conclusion. The modified Dunn procedure for severe SCFE resulted in a low rate of AVN, low risk of progression to OA, and high functional scores at long-term follow-up. The slip deformities were mainly corrected but secondary impingement deformities can develop in some hips and may require further surgical treatment. Cite this article: Bone Joint J 2019;101-B:403–414

The femoral head receives blood supply mainly from the deep branch of the medial femoral circumflex artery (MFCA). In previous studies we have performed anatomical dissections of 16 specimens and subsequently visualised the arteries supplying the femoral head in 55 healthy individuals. In this further radiological study we compared the arterial supply of the femoral head in 35 patients (34 men and one woman, mean age 37.1 years (16 to 64)) with a fracture/dislocation of the hip with a historical control group of 55 hips. Using CT angiography, we identified the three main arteries supplying the femoral head: the deep branch and the postero-inferior nutrient artery both arising from the MFCA, and the piriformis branch of the inferior gluteal artery. It was possible to visualise changes in blood flow after fracture/dislocation. Our results suggest that blood flow is present after reduction of the dislocated hip. The deep branch of the MFCA was patent and contrast-enhanced in 32 patients, and the diameter of this branch was significantly larger in the fracture/dislocation group than in the control group (p = 0.022). In a subgroup of ten patients with avascular necrosis (AVN) of the femoral head, we found a contrast-enhanced deep branch of the MFCA in eight hips. Two patients with no blood flow in any of the three main arteries supplying the femoral head developed AVN. Cite this article: Bone Joint J 2013;95-B:1453–7

We have compared different types of intertrochanteric osteotomy for avascular of necrosis of the hip and evaluated their performance in the light of improving outcome after total hip arthroplasty (THA). During a period of 14 years we performed 63 flexion osteotomies (partly combined with varus or valgus displacement), 29 rotational osteotomies, 13 varus osteotomies, eight medialising osteotomies and two extension osteotomies. The mean period of follow-up for all 115 operations was 7.3 years (maximum 24.6). At follow-up, 27 of 29 patients with a rotational osteotomy had already undergone a THA, compared with 36 of 63 after flexion osteotomy. A high incidence of complications (55.2%) was seen early after rotational osteotomy, compared with 17.5% after flexion osteotomy. For all osteotomies there was a high correlation between the size of the necrotic area and the incidence of failure, which also correlated with the preoperative Ficat and Steinberg stages. Using Kaplan-Meier survivorship analysis, Sugioka’s rotational osteotomy showed a survival probability after five years of 0.26 (95% confidence interval 0.49 to 0.14), and after ten years of 0.15 (CI 0.36 to 0.06). The survival probability for flexion osteotomy was 0.70 (CI 0.83 to 0.59) after five years and 0.50 (CI 0.65 to 0.38) after ten years. The subgroup of flexion osteotomy with a necrotic sector of less than 180° achieved the best survival probability of 0.90 (CI 1.00 to 0.80) after five years and 0.61 (CI 0.84 to 0.45) after ten years. The indications for intertrochanteric osteotomy for avascular necrosis of the hip have to be addressed critically. Even flexion osteotomy in cases with small areas of necrosis provides only temporary benefit. Rotational osteotomy was associated with a high incidence of complications

Symptomatic hip osteonecrosis is a disabling condition with a poorly understood aetiology and pathogenesis. Numerous treatment options for hip osteonecrosis are described, which include non-operative management and joint preserving procedures, as well as total hip replacement (THR). Non-operative or joint preserving treatment may improve outcomes when an early diagnosis is made before the lesion has become too large or there is radiographic evidence of femoral head collapse. The presence of a crescent sign, femoral head flattening, and acetabular involvement indicate a more advanced-stage disease in which joint preserving options are less effective than THR. Since many patients present after disease progression, primary THR is often the only reliable treatment option available. Prior to the 1990s, outcomes of THR for osteonecrosis were poor. However, according to recent reports and systemic reviews, it is encouraging that with the introduction of newer ceramic and/or highly cross-linked polyethylene bearings as well as highly-porous fixation interfaces, THR appears to be a reliable option in the management of end-stage arthritis following hip osteonecrosis in this historically difficult to treat patient population.

Cite this article: Bone Joint J 2013;95-B, Supple A:46–50.

We present the long-term results of simple varus intertrochanteric osteotomy for osteonecrosis of the femoral head. We followed 26 hips in 20 patients, with a mean age at the time of surgery of 36 years, for a mean of 12.5 years. The mean varus angulation was 23°.

The outcome in 19 of the hips (73%) was good or excellent; seven (27%) had a fair or poor result, with four needing some form of prosthetic arthroplasty.

Simple varus intertrochanteric osteotomy is indicated, even if the extent of the capital infarct comprises more than 50% of the diameter of maximum radial distance from the circumference, provided that after operation the medial necrotic lesion measures less than two-thirds of the weight-bearing area, and the superolateral bone is normal.

We performed a prospective study using MRI to evaluate early necrosis of the femoral head in 48 patients receiving high-dose corticosteroids for the treatment of various autoimmune-related disorders. The mean interval from the initiation of corticosteroid therapy to the first MRI examination was 2 months (0.5 to 6). MRI was repeated, and the mean period of follow-up was 31 months (24 to 69).

Abnormalities were found on MRI in 31 hips (32%). The initial changes showed well-demarcated, band-like zones which were seen at a mean of 3.6 months after initiation of treatment with steroids. In 14 of these hips (45%) there was a spontaneous reduction in the size of the lesions about one year after treatment had started, but there was no further change in size with a longer follow-up.

We present the histological findings of bone retrieved from beneath the femoral components of failed metal-on-metal hip resurfacing arthroplasties. Of a total of 377 patients who underwent resurfacing arthroplasty, 13 required revision; for fracture of the femoral neck in eight, loosening of a component in three and for other reasons in two. None of these cases had shown histological evidence of osteonecrosis in the femoral bone at the time of the initial implantation.

Bone from the remnant of the femoral head showed changes of osteonecrosis in all but one case at revision. In two cases of fracture which occurred within a week of implantation, the changes were compatible with early necrosis of the edge of the fracture. In the remaining six fractures, there were changes of established osteonecrosis. In all but one of the non-fracture cases, patchy osteonecrosis was seen.

We conclude that histological evidence of osteonecrosis is a common finding in failed resurfaced hips. Given that osteonecrosis is extensive in resurfaced femoral heads which fail by fracture, it is likely to play a role in the causation of these fractures.

Aims

One method of femoral head preservation following avascular necrosis (AVN) is core decompression and insertion of a tantalum rod. However, there may be a high failure rate associated with this procedure. The purpose of this study was to document the clinical and radiological outcomes following total hip arthroplasty (THA) subsequent to failed tantalum rod insertion.

Objectives

We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip.

A vascular necrosis (AVN) of the head of the femur is a potentially crippling disease which mainly affects young adults. Although treatment by exposure to hyperbaric oxygen (HBO) is reported as being beneficial, there has been no study of its use in treated compared with untreated patients. We selected 12 patients who suffered from Steinberg stage-I AVN of the head of the femur (four bilateral) whose lesions were 4 mm or more thick and/or 12.5 mm or more long on MRI. Daily HBO therapy was given for 100 days to each patient. All smaller stage-I lesions and more advanced stages of AVN were excluded. These size criteria were chosen in order to compare outcomes with an identical size of lesion in an untreated group described earlier. Overall, 81% of patients who received HBO therapy showed a return to normal on MRI as compared with 17% in the untreated group. We therefore conclude that hyperbaric oxygen is effective in the treatment of stage-I AVN of the head of the femur.

We report the outcome of 39 patients who underwent a modified Pauwels’ intertrochanteric osteotomy for nonunion of a femoral neck fracture following failed osteosynthesis. There were 31 men and eight women with a mean age of 47.2 years (34 to 59). By Pauwels’ classification, there were 11 Type II fractures and 28 Type III fractures. The mean follow-up was 7.9 years (2 to 19). In the 11 patients whose initial treatment had been osteotomy, union was achieved in nine (81.8%). In 28 patients whose initial treatment had been with a lag screw or a dynamic hip screw, union was achieved in 27 (96.4%). Limb lengths were equalised in 14 of 16 patients (87.5%) with pre-operative shortening. The mean neck-shaft angle improved significantly from 100.5° (80° to 120°) to 131.6° (120° to 155°) (p = 0.004). The mean modified Harris hip score was 85.6 points (70 to 97) and the mean modified Merle d’Aubigné score was 14.3 (11 to 18). Good to excellent functional outcomes were achieved in 32 patients (88.8%). A modified Pauwels’ intertrochanteric osteotomy is a reliable method of treating ununited fractures of the femoral neck following failed osteosynthesis: coxa vara and shortening can also simultaneously be addressed.

Cite this article: Bone Joint J 2014;96-B:1198–1201.

Segmental collapse occurs in the early stage of a vascular necrosis (AVN) of the femoral head, and is associated with a poor prognosis. Since it develops at a relatively young age, the long-term outcome after total hip replacement is a major concern. We have compared the long-term results of pedicle bone grafting (PBG) with those of transtrochanteric rotational osteotomy (TRO). In the PBG group there were 23 men (27 hips) and three women (4 hips) with a mean age at the time of surgery of 38 years and a mean follow-up of 13 years. In the TRO group there were 44 men (55 hips) and 19 women (22 hips) with a mean age at the time of surgery of 39 years and a mean follow-up of seven years. Failure was defined as a need for total hip replacement or a Harris hip score below 70.

The long-term results were similar for the two groups. The survival rates at five and ten years were 85% and 67%, respectively, in the PBG group, and 71% and 61%, respectively, in the TRO group, according to Kaplan-Meier survivorship analysis. In the TRO group patients in stage II had significantly better results that those in stage III.

The femoral head receives its blood supply primarily from the medial femoral circumflex artery, with its deep branch being the most important.

In a previous study, we performed classical anatomical dissections of 16 hips. We have extended our investigation with a radiological study, in which we aimed to visualise the arteries supplying the femoral head in healthy individuals. We analysed 55 CT angiographic images of the hip.

Using 64-row CT angiography, we identified three main arteries supplying the femoral head: the deep branch of the medial femoral circumflex artery and the posterior inferior nutrient artery originating from the medial femoral circumflex artery, and the piriformis branch of the inferior gluteal artery. CT angiography is a good method for visualisation of the arteries supplying the femoral head. The current radiological studies will provide information for further investigation of vascularity after traumatic dislocation of the hip, using CT angiography.

Aims. The aims of the study were to report for a cohort aged younger than 40 years: 1) indications for HRA; 2) patient-reported outcomes in terms of the modified Harris Hip Score (HHS); 3) dislocation rate; and 4) revision rate. Methods. This retrospective analysis identified 267 hips from 224 patients who underwent an hip resurfacing arthroplasty (HRA) from a single fellowship-trained surgeon using the direct lateral approach between 2007 and 2019. Inclusion criteria was minimum two-year follow-up, and age younger than 40 years. Patients were followed using a prospectively maintained institutional database. Results. A total of 217 hips (81%) were included for follow-up analysis at a mean of 3.8 years. Of the 23 females who underwent HRA, none were revised, and the median head size was 46 mm (compared to 50 mm for males). The most common indication for HRA was femoroacetabular impingement syndrome (n = 133), and avascular necrosis ( (n = 53). Mean postoperative HHS was 100 at two and five years. No dislocations occurred. A total of four hips (1.8%) required reoperation for resection of heterotopic ossification, removal of components for infection, and subsidence with loosening. The overall revision rate was 0.9%. Conclusion. For younger patients with higher functional expectations and increased lifetime risk for revision, HRA is an excellent bone preserving intervention carrying low complication rates, revision rates, and excellent patient outcomes without lifetime restrictions allowing these patients to return to activity and sport. Thus, in younger male patients with end-stage hip disease and higher demands, referral to a high-volume HRA surgeon should be considered. Cite this article: Bone Jt Open 2023;4(6):408–415