Aims. This study aimed to investigate the incidence of ≥ 5 mm asymmetry in lower and whole leg lengths (LLs) in patients with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH-OA) and primary hip osteoarthritis (PHOA), and the relationship between lower and whole LL asymmetries and femoral length asymmetry. Methods. In total, 116 patients who underwent unilateral total hip arthroplasty were included in this study. Of these, 93 had DDH-OA and 23 had PHOA. Patients with DDH-OA were categorized into three groups: Crowe grade I, II/III, and IV. Anatomical femoral length, femoral length greater trochanter (GT), femoral length lesser trochanter (LT), tibial length, foot height, lower LL, and whole LL were evaluated using preoperative CT data of the whole leg in the supine position. Asymmetry was evaluated in the Crowe I, II/III, IV, and PHOA groups. Results. The incidences of whole and lower LL asymmetries were 40%, 62.5%, 66.7%, and 26.1%, and 21.7%, 20.8%, 55.6%, and 8.7% in the Crowe I, II/III, and IV, and PHOA groups, respectively. The incidence of tibial length asymmetry was significantly higher in the Crowe IV group (44.4%) than that in the PHOA group (4.4%). In all, 50% of patients with DDH-OA with femoral length GT and LT asymmetries had lower LL asymmetry, and 75% had whole LL asymmetry. The incidences of lower and whole LL asymmetries were 20% and 42.9%, respectively, even in the absence of femoral length GT and LT asymmetries. Conclusion. Overall, 43% of patients with unilateral DDH-OA without femoral length asymmetry had whole LL asymmetry of ≥ 5 mm. Thus, both the femur length and whole LL should be measured to accurately assess LL discrepancy in patients with unilateral DDH-OA. Cite this article: Bone Jt Open 2024;5(2):79–86

Aims. The aim of this study was to report the long-term follow-up of cemented short Exeter femoral components when used in primary total hip arthroplasty (THA). Methods. We included all primary 394 THAs with a cemented short Exeter femoral component (≤ 125 mm) used in our tertiary referral centre between October 1993 and December 2021. A total of 83 patients (21%) were male. The median age of the patients at the time of surgery was 42 years (interquartile range (IQR) 30 to 55). The main indication for THA was a childhood hip disease (202; 51%). The median follow-up was 6.7 years (IQR 3.1 to 11.0). Kaplan-Meier survival analyses were performed to determine the rates of survival with femoral revision for any indication, for septic loosening, for fracture of the femoral component and for aseptic loosening as endpoints. The indications for revision were evaluated. Fractures of the femoral component were described in detail. Results. The 20-year rate of survival was 85.4% (95% confidence interval (CI) 73.9 to 92.0) with revision for any indication, 96.2% (95% CI 90.5 to 98.5) with revision for septic loosening and 92.7% (95% CI 78.5 to 97.6) with revision for fracture of the femoral component. No femoral components were revised for aseptic loosening. There were 21 revisions of the femoral component; most (seven) as part of a two-stage management of infection. Fracture of the femoral component occurred in four THAs (1.0%) at 6.6, 11.6, 16.5, and 18.2 years of follow-up, respectively. Three of these were transverse fractures and occurred at the level of the lesser trochanter. In one THA, there was a fracture of the neck of the component. Conclusion. THAs using cemented short Exeter femoral components showed acceptable rates of survival of the femoral component at long-term follow-up, in this young cohort of patients. Although fracture is a rare complication of these components, surgeons should be aware of their incidence and possible risk factors. Cite this article: Bone Joint J 2024;106-B(3 Supple A):137–142

Aims

This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.

Aims. The aim of this study was to examine whether hips with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH) have significant asymmetry in femoral length, and to determine potential related factors. Patients and Methods. We enrolled 90 patients (82 female, eight male) with DDH showing unilateral OA changes, and 43 healthy volunteers (26 female, 17 male) as controls. The mean age was 61.8 years (39 to 93) for the DDH groups, and 71.2 years (57 to 84) for the control group. Using a CT-based coordinate measurement system, we evaluated the following vertical distances: top of the greater trochanter to the knee centre (femoral length GT), most medial prominence of the lesser trochanter to the knee centre (femoral length LT), and top of the greater trochanter to the medial prominence of the lesser trochanter (intertrochanteric distance), along with assessments of femoral neck anteversion and neck shaft angle. Results. The percentages of hips with an absolute difference of > 5 mm in femoral GT and LT lengths were significantly larger in the DDH group (24% for both) compared with those of the control group (2% and 7%, respectively). The femoral length GT of the affected femur was significantly shorter in Crowe I and longer in Crowe IV than that of the unaffected side. The affected-to-unaffected difference of the intertrochanteric distance showed positive correlation with that of the femoral length GT in Crowe I and Crowe II/III, and negative correlation with that of the femoral length LT in the Crowe I and Crowe IV groups. Conclusion. Hips with unilateral end-stage OA secondary to DDH show significant asymmetry in femoral length between both the greater and lesser trochanter and the knee compared with controls. The intertrochanteric distance was a morphological factor related to femoral-length asymmetry. When undertaking total hip arthroplasty (THA) in the presence of DDH, long leg radiographs or CT measurements should be used to assess true leg-length discrepancy. Cite this article: Bone Joint J 2019;101-B:297–302

Aims. The diversity of femoral morphology renders femoral component sizing in total hip arthroplasty (THA) challenging. We aimed to determine whether femoral morphology and femoral component filling influence early clinical and radiological outcomes following THA using fully hydroxyapatite (HA)-coated femoral components. Methods. We retrospectively reviewed records of 183 primary uncemented THAs. Femoral morphology, including Dorr classification, canal bone ratio (CBR), canal flare index (CFI), and canal-calcar ratio (CCR), were calculated on preoperative radiographs. The canal fill ratio (CFR) was calculated at different levels relative to the lesser trochanter (LT) using immediate postoperative radiographs: P1, 2 cm above LT; P2, at LT; P3, 2 cm below LT; and D1, 7 cm below LT. At two years, radiological femoral component osseointegration was evaluated using the Engh score, and hip function using the Postel Merle d’Aubigné (PMA) and Oxford Hip Score (OHS). Results. CFR was moderately correlated with CCR at P1 (r = 0.44; p < 0.001), P2 (r = 0.53; p < 0.001), and CFI at P1 (r = − 0.56; p < 0.001). Absence of spot welds (n = 3, 2%) was associated with lower CCR (p = 0.049), greater CFI (p = 0.017), and lower CFR at P3 (p = 0.015). Migration (n = 9, 7%) was associated with lower CFR at P2 (p = 0.028) and P3 (p = 0.007). Varus malalignment (n = 7, 5%), predominantly in Dorr A femurs (p = 0.028), was associated with lower CFR at all levels (p < 0.05). Absence of spot welds was associated with lower PMA gait (p = 0.012) and migration with worse OHS (p = 0.032). Conclusion. This study revealed that femurs with insufficient proximal filling tend to have less favourable radiological outcomes following uncemented THA using a fully HA-coated double-tapered femoral component. Cite this article: Bone Joint Res. 2020;9(4):182–191

Aims. A lack of supporting clinical studies have been published to determine the ideal length of intramedullary nail in fixation of trochanteric fractures of the hip. Nevertheless, there has been a trend to use shorter intramedullary nails for the internal fixation of trochanteric hip fractures. Our aim was to determine if the length of nail affected the outcome. Methods. We randomized 229 patients with a trochanteric hip fracture between two implants: a ‘standard’ nail of 220 mm and a shorter nail of 175 mm, which had decreased proximal angulation (4° vs 7°) and a reduced diameter at the level of the lesser trochanter. Patients were followed up for one year by a nurse blinded to the type of implant used to determine if there were differences in mobility and pain with two nail designs. Pain was assessed on a scale of 1 (none) to 8 (severe and constant) and mobility on a scale of 1 (full mobility) to 9 (immobile). Results. The shorter nail did not require any reaming of the femur and was quicker to insert (mean difference 5.1 minutes; p < 0.001, 95% confidence interval (CI) of the difference 3.16 to 7.04). Those treated by the shorter nail were less mobile (mean difference in reduction in mobility score at one year 0.80; p = 0.007, 95% CI 1.38 to 0.22). In addition, there was a trend toward greater residual pain for those treated with the shorter nail, although this was not statistically significant (mean difference in pain score at one year 0.24; p = 0.064, 95% CI -0.01 to 0.49). Conclusion. These results suggest that the increasing use of this very short intramedullary nail with its design modification may not be appropriate. Cite this article: Bone Joint J 2020;102-B(3):394–399

Femoroacetabular impingement is a well-documented cause of hip pain. There is, however, increasing evidence for the presence of a previously unrecognised impingement-type condition around the hip – ischiofemoral impingement. This is caused by abnormal contact between the lesser trochanter of the femur and the ischium, and presents as atypical groin and/or posterior buttock pain. The symptoms are gradual in onset and may be similar to those of iliopsoas tendonitis, hamstring injury or bursitis. The presence of ischiofemoral impingement may be indicated by pain caused by a combination of hip extension, adduction and external rotation. Magnetic resonance imaging demonstrates inflammation and oedema in the ischiofemoral space and quadratus femoris, and is distinct from an acute tear. To date this has only appeared in the specialist orthopaedic literature as a problem that has developed after total hip replacement, not in the unreplaced joint

Aims. We have evaluated the survivorship, outcomes, and failures of an interlocking, reconstruction-mode stem-sideplate implant used to preserve the native hip joint and achieve proximal fixation when there is little residual femur during large endoprosthetic reconstruction of the distal femur. Methods. A total of 14 patients underwent primary or revision reconstruction of a large femoral defect with a short remaining proximal femur using an interlocking, reconstruction-mode stem-sideplate for fixation after oncological distal femoral and diaphyseal resections. The implant was attached to a standard endoprosthetic reconstruction system. The implant was attached to a standard endoprosthetic reconstruction system. None of the femoral revisions were amenable to standard cemented or uncemented stem fixation. Patient and disease characteristics, surgical history, final ambulatory status. ,. and Musculoskeletal Tumor Society (MSTS) score were recorded. The percentage of proximal femur remaining was calculated from follow-up radiographs. Results. All 14 at-risk native hip joints were preserved at a mean final follow-up of 6.0 years (SD 3.7), despite a short residual femur, often after proximal osteotomies through the lesser trochanter. Overall, 13 of 14 stems had long-term successful fixation. Eight patients required no reoperation. Three patients required reoperation due to implant-related issues, and three patients required reoperation for wound healing problems or infection. There were no dislocations or fractures. At final follow-up the mean MSTS score was 24.9 (SD 4.1). Nine patients required no ambulation aids, and only one had a Trendelenburg gait. Conclusion. This interlocking, reconstruction-mode stem-sideplate reliably preserves native hip joint anatomy and function after large femoral resection with a short remaining proximal femur, both in the primary and revision setting. This is particularly important for preventing or delaying total femoral arthroplasty in young patients after oncological reconstruction. Hip abductor strength and function could be maintained by this method, and the risk of dislocation eliminated. The success of this technique in this modest series should be verified in a larger collaborative study and will be of interest to revision surgeons and oncologists. Cite this article: Bone Joint J 2021;103-B(2):398–404

Resurfacing arthroplasty of the hip is being used increasingly as an alternative to total hip replacement, especially for young active patients. There is concern about necrosis of the femoral head after resurfacing which can result in fracture and loosening. Most systems use a cemented femoral component, with the potential for thermal necrosis of the cancellous bone of the reamed femoral head. We used thermal probes to record temperatures close to the cement-bone interface during resurfacing arthroplasty. The maximum temperature recorded at the cement-bone interface in four cases was approximately 68°C which was higher than that reported to kill osteocytes. A modified surgical technique using insertion of a suction cannula into the lesser trochanter, generous pulsed lavage and early reduction of the joint significantly reduced the maximum recorded cancellous bone temperature to approximately 36°C in five cases (p = 0.014). We recommend the modified technique since it significantly reduces temperatures at the cement-bone interface

To define the natural history of bone loss around a femoral prosthesis, the bone mineral content and bone mineral density were measured for each femur in 28 patients with unilateral total hip arthroplasty, 18 age-matched controls, and seven patients with unilateral osteoarthritis. The areas measured were inside the lesser trochanter and 4.8 cm distal to it. The contralateral hip served as the control. Three years after arthroplasty there was 40% loss in average bone mineral content inside the lesser trochanter, and 28% loss in average bone mineral content 4.8 cm distally in the medial cortex. At seven to 14 years after operation, patients had lost 40% of bone proximally and 49% distally. The data suggest that this may progress in a proximal-to-distal fashion, and could account for a 50% decrease in bone mass seven to 14 years after surgery

We present the case of a 65-year-old man who developed a malignant fibrous histiocytoma at the lesser trochanter five months after a cementless hip replacement. We have reviewed reports of similar cases and discuss them in terms of the possible mechanisms of sarcomatous degeneration and the latency of such changes

1. A patient of sixty-eight suffering from enchondromatosis (Ollier's disease) is described. 2. A malignant tumour developed in the region of the lesser trochanter of the femur. Histological investigation established that it was an osteosarcoma. 3. Other features of interest are the radiographic appearance of Ollier's disease at an advanced age, and the presence of subcutaneous subcostal and retroperitoneal haemangiomata

Our aim was to assess the local extent of osteocyte death in the proximal femur of 16 patients with osteonecrosis of the femoral head. We performed histological examination of the femoral heads and cancellous bone biopsies from four regions of the proximal femur in patients undergoing total hip arthroplasty. A control group consisted of 19 patients with osteoarthritis. All histological specimens were examined in a blinded fashion. Extensive osteonecrosis was shown in the proximal femur up to 4 cm below the lesser trochanter in the group with osteonecrosis. There was an overall statistically significant difference in the extent of osteocyte death distal to the femoral head between the two groups (p < 0.001). We discuss the implications of these findings as possible contributing factors in regard to the early failure of total hip arthroplasty reported in patients with osteonecrosis of the femoral head

Aims

Traditionally, total hip arthroplasty (THA) templating has been performed on anteroposterior (AP) pelvis radiographs. Recently, additional AP hip radiographs have been recommended for accurate measurement of the femoral offset (FO). To verify this claim, this study aimed to establish quantitative data of the measurement error of the FO in relation to leg position and X-ray source position using a newly developed geometric model and clinical data.

Our study describes the mid-term clinical results of the use of transtrochanteric valgus osteotomy (TVO) for the treatment of osteoarthritis of the hip secondary to acetabular dysplasia. The operation included valgus displacement at the level of the lesser trochanter, and lateral displacement of the greater trochanter by inserting a wedge of bone. We reviewed 70 hips. The mean age of the patients at operation was 44 years (14 to 59). Most (90%) had advanced osteoarthritis. The scores for pain and gait had improved significantly at a mean follow-up of 9.4 years. The rate of survival until an endpoint of a further operation during a follow-up of ten years was 82%. The survival rate was 95% in patients with unilateral involvement who were less than 50 years of age at operation. TVO is a useful form of treatment for advanced osteoarthritis of the hip, particularly in young patients with unilateral disease

Hereditary multiple exostoses is an autosomal dominant disorder characterised by multiple osteochondromata, most commonly affecting the forearm, knee and ankle. Osteochondromata of the proximal femur have been reported to occur in 30% to 90% of affected patients with coxa valga in 25%. Acetabular dysplasia is rare but has been described. This is the first report of a patient requiring surgical intervention. A girl was seen at the age of nine with hereditary multiple exostoses and when 12 developed bilateral pain in the groin. Radiographs showed severely dysplastic acetabula with less than 50% coverage of the femoral heads and widening of the medial joint space. Large sessile osteochondromata were present along the medial side of the femoral neck proximal to the lesser trochanter, with associated coxa valga. The case illustrates the importance of obtaining initial skeletal surveys in children with hereditary multiple exostoses to identify potential problems such as acetabular dysplasia and subluxation of the hip

Aims

This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged less than 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component.

Ten uncemented total hip replacements were performed in 1975 using an implant in which the cobalt-chrome femoral stem was coated to give a porous surface. In all but one case a high-density polyethylene head was used. The radiological changes in the upper femoral shafts were assessed between three and nine years later. Seven showed extensive stress-relieving changes, loss of calcar, stress fractures at the root of the lesser trochanter with subsequent detachment, and osteoporosis followed by avulsion of the greater trochanter. In these seven patients the lower part of the stem appeared to be soundly embedded, although in only one was there evidence of bony incorporation. It is suggested that if the fixation of a fully coated implant of this sort remains sound, gross atrophy of the upper femoral shaft develops after five years. This atrophy, associated with an implant which can be removed only at the expense of further bone destruction, presents substantial problems if revision is needed

1. If a vertical load is applied to the head of the femur parallel to its shaft, the upper cortex is stretched and the lower cortex is compressed. The neck breaks from the upper subcapital border to the lesser trochanter. This type of fracture is rarely found clinically. 2. If a compressive force is applied to the area between head and greater trochanter while the head is loaded vertically, a transverse fracture of clinical appearance is produced. If this axial pressure acts along the part of the neck above the central axis a subcapital comminuted fracture results. If the pressure acts below the central axis the result is a transcervical fracture. 3. Strain gauge experiments have shown that axial compression within the upper segment of the neck is produced by the abductor muscles of the hip. Adductor muscles produce a low axial compression. It is suggested that muscular action at the time of injury influences the type of fracture produced by the injury