Aims. Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation. Methods. A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables. Results. The dislocation rate was 13.9% (n = 17). The hip COR was found to be significantly shifted anteriorly and inferiorly in most patients in the dislocation group compared with the non-dislocation group. Three independent risk factors were found to be related to dislocation: resection of gluteus medius (odds ratio (OR) 3.68 (95% confidence interval (CI) 1.24 to 19.70); p = 0.039), vertical shift of COR > 18 mm (OR 24.8 (95% CI 6.23 to 128.00); p = 0.001), and sagittal shift of COR > 20 mm (OR 6.22 (95% CI 1.33 to 32.2); p = 0.026). Conclusion. Among the 17 patients who dislocated, 70.3% (n = 12) were anterior dislocations. Three independent risk factors were identified, suggesting the importance of proper restoration of the COR and the role of the gluteus medius in maintaining hip joint stability. Cite this article: Bone Joint J 2022;104-B(10):1180–1188

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

Aims. The aim of this study was to evaluate the efficacy of the surgical dislocation approach and modified trapdoor procedure for the treatment of chondroblastoma of the femoral head. Patients and Methods. A total of 17 patients (ten boys, seven girls; mean age 16.4 years (11 to 26)) diagnosed with chondroblastoma of the femoral head who underwent surgical dislocation of the hip joint, modified trapdoor procedure, curettage, and bone grafting were enrolled in this study and were followed-up for a mean of 35.9 months (12 to 76). Healing and any local recurrence were assessed via clinical and radiological tests. Functional outcome was evaluated using the Musculoskeletal Tumour Society scoring system (MSTS). Patterns of bone destruction were evaluated using the Lodwick classification. Secondary osteoarthritis was classified via radiological analysis following the Kellgren–Lawrence grading system. Steinberg classification was used to evaluate osteonecrosis of the femoral head. Results. The epiphyseal plate was open, closing, and closed in five, five, and seven patients, respectively. In total, eight, six, and three patients were classified as having Lodwick classification IA, IB, and IC, respectively. Allogeneic and autogenous bone grafting was used in 13 and four patients, respectively. All patients had good bone healing and no local recurrence was observed. One patient developed osteonecrosis of the femoral head (Steinberg IA) and one developed secondary osteoarthritis of the hip joint (Kellgren–Lawrence Grade II). The mean postoperative MSTS functional score was 27.7 (24 to 30). Conclusion. Surgical dislocation and modified trapdoor procedures are safe and effective techniques for treating chondroblastoma in the femoral head. Cite this article: Bone Joint J 2019;101-B:732–738

Aims

The sacroiliac joint (SIJ) is the only mechanical connection between the axial skeleton and lower limbs. Following iliosacral resection, there is debate on whether reconstruction of the joint is necessary. There is a paucity of data comparing the outcomes of patients undergoing reconstruction and those who are not formally reconstructed.

Aims

The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours.

Aims

Internal hemipelvectomy without reconstruction of the pelvis is a viable treatment for pelvic sarcoma; however, the time it takes to return to excellent function is quite variable. Some patients require greater time and rehabilitation than others. To determine if psoas muscle recovery is associated with changes in ambulatory function, we retrospectively evaluated psoas muscle size and limb-length discrepancy (LLD) before and after treatment and their correlation with objective functional outcomes.

Aims

Iliosacral sarcoma resections have been shown to have high rates of local recurrence (LR) and poor overall survival. There is also no universal classification for the resection of pelvic sarcomas invading the sacrum. This study proposes a novel classification system and analyzes the survival and risk of recurrence, when using this system.

Aims

There is an increased risk of dislocation of the hip after the resection of a periacetabular tumour and endoprosthetic reconstruction of the defect in the hemipelvis. The aim of this study was to determine the rate and timing of dislocation and to identify its risk factors.

Aims

Limb salvage for pelvic sarcomas involving the acetabulum is a major surgical challenge. There remains no consensus about what is the optimum type of reconstruction after resection of the tumour. The aim of this study was to evaluate the surgical outcomes in these patients according to the methods of periacetabular reconstruction.

Aims

Iliac wing (Type I) and iliosacral (Type I/IV) pelvic resections for a primary bone tumour create a large segmental defect in the pelvic ring. The management of this defect is controversial as the surgeon may choose to reconstruct it or not. When no reconstruction is undertaken, the residual ilium collapses back onto the remaining sacrum forming an iliosacral pseudarthrosis. The aim of this study was to evaluate the long-term oncological outcome, complications, and functional outcome after pelvic resection without reconstruction.

Aims

Survival rates and local control after resection of a sarcoma of the pelvis compare poorly to those of the limbs and have a high incidence of complications. The outcome for patients who need a hindquarter amputation (HQA) to treat a pelvic sarcoma is poor. Our aim was to evaluate the patient, tumour, and reconstructive factors that affect the survival of the patients who undergo HQA for primary or recurrent pelvic sarcoma.

Excision of the proximal femur for tumour with prosthetic reconstruction using a bipolar femoral head places a considerable load on the unreplaced acetabulum. . We retrospectively reviewed the changes which occur around the affected hip joint by evaluating the post-operative radiographs of 65 consecutive patients who underwent proximal prosthetic arthroplasty of the femur, and in whom an acetabular component had not been used. There were 37 men and 28 women with a mean age of 57.3 years (17 to 93). Radiological assessment included the extent of degenerative change in the acetabulum, heterotopic ossification, and protrusio acetabuli. . The mean follow-up was 9.1 years (2 to 11.8). Degenerative changes in the acetabulum were seen in three patients (4.6%), Brooker grade 1 or 2 heterotopic ossification in 17 (26%) and protrusion of the prosthetic head in nine (13.8%). . A total of eight patients (12.3%) needed a revision. Five were revised to the same type of prosthesis and three (4.6%) were converted to a total hip arthroplasty. . We conclude that radiological evidence of degenerative change, heterotopic ossification and protrusion occur in a few patients who undergo prosthetic arthroplasty of the proximal femur for tumour. The limited extent of these changes and the lack of associated symptoms do not justify the routine arthroplasty of the acetabulum in these patients. . Cite this article: Bone Joint J 2015;97-B:1704–9

Aims

The consensus is that bipolar hemiarthroplasty (BHA) in allograft-prosthesis composite (APC) reconstruction of the proximal femur following primary tumour resection provides more stability than total hip arthroplasty (THA). However, no comparative study has been performed. In this study, we have compared the outcome and complication rates of these two methods.

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The aim of this study was to present the long-term surgical outcomes, complications, implant survival, and causes of implant failure in patients treated with the modified Harrington procedure using antegrade large diameter pins.

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The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR).

Aims

Pelvic reconstruction after the resection of a tumour around the acetabulum is a challenging procedure due to the complex anatomy and biomechanics. Several pelvic endoprostheses have been introduced, but the rates of complication remain high. Our aim was to review the use of a stemmed acetabular pedestal cup in the management of these patients.

Aims

Instability of the hip is the most common mode of failure after reconstruction with a proximal femoral arthroplasty (PFA) using an endoprosthesis after excision of a tumour. Small studies report improved stability with capsular repair of the hip and other techniques, but these have not been investigated in a large series of patients. The aim of this study was to evaluate variables associated with the patient and the operation that affect post-operative stability. We hypothesised an association between capsular repair and stability.

Aims

The aim of the study was to investigate the controversial issue of whether the pelvic ring should be reconstructed following resection of the sarcomas of the ilium.

Aims

We report a prospective cohort study of the midterm results of surgical dislocation of the hip (according to Ganz) to perform resection of osteochondromas involving the femoral neck in patients with multiple hereditary exostoses (MHE).

Giant cell tumour is the most common aggressive benign tumour of the musculoskeletal system and has a high rate of local recurrence. When it occurs in proximity to the hip, reconstruction of the joint is a challenge. Options for reconstruction after wide resection include the use of a megaprosthesis or an allograft-prosthesis composite. We performed a clinical and radiological study to evaluate the functional results of a proximal femoral allograft-prosthesis composite in the treatment of proximal femoral giant cell tumour after wide resection. This was an observational study, between 2006 and 2012, of 18 patients with a mean age of 32 years (28 to 42) and a mean follow-up of 54 months (18 to 79). We achieved excellent outcomes using Harris Hip Score in 13 patients and a good outcome in five. All allografts united. There were no complications such as infection, failure, fracture or resorption of the graft, or recurrent tumour. Resection and reconstruction of giant cell tumours with proximal femoral allograft–prosthesis composite is a better option than using a prosthesis considering preservation of bone stock and excellent restoration of function.

A good result requires demanding bone banking techniques, effective measures to prevent infection and stability at the allograft-host junction.

Cite this article: Bone Joint J 2014; 96-B:1106–10.

Deformity of the proximal femur in fibrous dysplasia leads to deviation of the mechanical axis of the hip, which may lead to the development of secondary osteoarthritis (OA). This study investigated the prevalence and predisposing factors for the development of OA in patients with fibrous dysplasia of the proximal femur. We reviewed the records of 209 patients from our institutional database with fibrous dysplasia of the proximal femur, investigating possible predisposing factors including patient demographics, the extent of the coxa vara deformity, the presence of peri-articular disease, and the overall burden of skeletal disease. Of the 209 patients, 24 (12%) had radiological evidence of OA in the ipsilateral hip. The prevalence was significantly higher in patients with polyostotic fibrous dysplasia compared with those with monostotic disease (p < 0.001). In a subgroup analysis of patients with polyostotic disease, the extent of deformity (quantified using the neck–shaft angle), and the presence of peri-articular disease (whether in the head of the femur or the acetabulum) were significant predictors of osteoarthritis (neck–shaft angle likelihood ratio (LR) = 0.847 per 1° increase, p = 0.004; presence of lesion in the head of the femur LR = 9.947, p = 0.027; presence of lesion in the acetabulum LR = 11.231, p = 0.014).

Our data suggest that patients with polyostotic fibrous dysplasia have a high risk of developing secondary OA of the hips. This risk is higher in patients with peri-articular disease, and those with a more severe deformity of proximal femur.

Cite this article: Bone Joint J 2015;97-B:1007–11.

The purpose of this study was to assess whether the use of a joint-sparing technique such as curettage and grafting was successful in eradicating giant cell tumours of the proximal femur, or whether an alternative strategy was more appropriate.

Between 1974 and 2012, 24 patients with a giant cell tumour of the proximal femur were treated primarily at our hospital. Treatment was either joint sparing or joint replacing. Joint-sparing treatment was undertaken in ten patients by curettage with or without adjunctive bone graft. Joint replacement was by total hip replacement in nine patients and endoprosthetic replacement in five. All 11 patients who presented with a pathological fracture were treated by replacement.

Local recurrence occurred in five patients (21%): two were treated by hip replacement, three by curettage and none with an endoprosthesis. Of the ten patients treated initially by curettage, six had a successful outcome without local recurrence and required no further surgery. Three eventually needed a hip replacement for local recurrence and one an endoprosthetic replacement for mechanical failure. Thus 18 patients had the affected joint replaced and only six (25%) retained their native joint. Overall, 60% of patients without a pathological fracture who were treated with curettage had a successful outcome.

Cite this article: Bone Joint J 2014;96-B:127–31.

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution.

We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients.

Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control.

The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Cite this article: Bone Joint J 2015;97-B:258–64.

The aim of this study was to evaluate the functional and oncological outcome of extracorporeally irradiated autografts used to reconstruct the pelvis after a P1/2 internal hemipelvectomy.

The study included 18 patients with a primary malignant bone tumour of the pelvis. There were 13 males and five females with a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic sarcoma, six a Ewing’s sarcoma, and five a chondrosarcoma. At a mean follow-up of 51.6 months (4 to 185), nine patients had died with metastatic disease while nine were free from disease. Local recurrence occurred in three patients all of whom eventually died of their disease. Deep infection occurred in three patients and required removal of their graft in two while the third underwent a hindquarter amputation for extensive flap necrosis.

The mean Musculoskeletal Tumor Society functional score of the 16 patients who could be followed-up for at least 12 months was 77% (50 to 90). Those 15 patients who completed the Toronto Extremity Salvage Score questionnaire had a mean score of 71% (53 to 85).

Extracorporeal irradiation and re-implantation of bone is a valid method of reconstruction after an internal hemipelvectomy. It has an acceptable morbidity and a functional outcome that compares favourably with other available reconstructive techniques.

Cite this article: Bone Joint J 2014;96-B:1404–10

We report our early experience with the use of a new prosthesis, the Modular Hemipelvic Prosthesis II, for reconstruction of the hemipelvis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint.

We retrospectively reviewed the outcome of 17 patients who had undergone resection of a pelvic tumour and reconstruction with this prosthesis between July 2002 and July 2010.

One patient had a type I+II+III+IV resection (ilium + peri-acetabulum + pubis/ischium + sacrum) and 16 had a type I+II+IV resection (ilium + acetabulum + sacrum). The outcome was assessed at a mean follow-up of 33 months (15 to 59). One patient was alive with disease, 11 were alive without disease and five had died of disease. The overall five-year survival rate was 62.4%. Six patients had a local recurrence. The mean Musculoskeletal Tumour Society score was 58% (33 to 77). Deep infection occurred in two patients, problems with wound healing in five and dislocation in one.

For patients with a primary malignant peri-acetabular sarcoma involving the sacroiliac joint, we believe that this new prosthesis is a viable option for reconstruction of the bony defect left following resection of the tumour. It results in a satisfactory functional outcome with an acceptable rate of complications.

Cite this article: Bone Joint J 2014;96-B:399–405.

We hypothesised that the use of computer navigation-assisted surgery for pelvic and sacral tumours would reduce the risk of an intralesional margin. We reviewed 31 patients (18 men and 13 women) with a mean age of 52.9 years (13.5 to 77.2) in whom computer navigation-assisted surgery had been carried out for a bone tumour of the pelvis or sacrum. There were 23 primary malignant bone tumours, four metastatic tumours and four locally advanced primary tumours of the rectum. The registration error when using computer navigation was <  1 mm in each case. There were no complications related to the navigation, which allowed the preservation of sacral nerve roots (n = 13), resection of otherwise inoperable disease (n = 4) and the avoidance of hindquarter amputation (n = 3). The intralesional resection rate for primary tumours of the pelvis and sacrum was 8.7% (n = 2): clear bone resection margins were achieved in all cases. At a mean follow-up of 13.1 months (3 to 34) three patients (13%) had developed a local recurrence. The mean time alive from diagnosis was 16.8 months (4 to 48).

Computer navigation-assisted surgery is safe and has reduced our intralesional resection rate for primary tumours of the pelvis and sacrum. We recommend this technique as being worthy of further consideration for this group of patients.

Cite this article: Bone Joint J 2013;95-B:1417–24.

Disarticulation of the hip in patients with high-grade tumours in the upper thigh results in significant morbidity. In patients with no disease of the proximal soft tissue a femoral stump may be preserved, leaving a fulcrum for movement and weight-bearing. We reviewed nine patients in whom the oncological decision would normally be to disarticulate, but who were treated by implantation of an endoprosthesis in order to create a functioning femoral stump. The surgery was undertaken for chondrosarcoma in four patients, pleomorphic sarcoma in three, osteosarcoma in one and fibrous dysplasia in one. At follow-up at a mean of 80 months (34 to 132), seven patients were alive and free from disease, one had died from lung metastases and another from a myocardial infarction. The mean functional outcome assessment was 50 (musculoskeletal tumor society), 50 and 60 (physical and mental Short-form 36 scores).

Implantation of an endoprosthesis into the stump in carefully selected patients allows fitting of an above-knee prosthesis and improves wellbeing and the functional outcome.

Endoprosthetic replacement of the pelvis is one of the most challenging types of limb-salvage surgery, with a high rate of complications. In an attempt to reduce this and build greater versatility into the reconstruction process, a new type of pelvic endoprosthesis was developed in 2003, based on the old McKee-Farrar prosthesis. This study reviews the outcomes in 27 patients who had an ice-cream cone pelvic prosthesis inserted at two different specialist bone tumour centres in the United Kingdom over the past six years. The indications for treatment included primary bone tumours in 19 patients and metastatic disease in two, and six implants were inserted following failure of a previous pelvic reconstruction. Most of the patients had a P2+P3 resection as classified by Enneking, and most had resection of the ilium above the sciatic notch. The mean age of the patients at operation was 49 years (13 to 81). Complications occurred in ten patients (37.0%), of which dislocation was the most common, affecting four patients (14.8%). A total of three patients (11.1%) developed a deep infection around the prosthesis but all were successfully controlled by early intervention and two patients (7.4%) developed a local recurrence, at the same time as widespread metastases appeared. In one patient the prosthesis was removed for severe pain.

This method of treatment is still associated with high morbidity, but early results are promising. Complications are diminishing with increasing experience.

Giant cell tumours (GCT) of the synovium and tendon sheath can be classified into two forms: localised (giant cell tumour of the tendon sheath, or nodular tenosynovitis) and diffuse (diffuse-type giant cell tumour or pigmented villonodular synovitis). The former principally affects the small joints. It presents as a solitary slow-growing tumour with a characteristic appearance on MRI and is treated by surgical excision. There is a significant risk of multiple recurrences with aggressive diffuse disease. A multidisciplinary approach with dedicated MRI, histological assessment and planned surgery with either adjuvant radiotherapy or systemic targeted therapy is required to improve outcomes in recurrent and refractory diffuse-type GCT.

Although arthroscopic synovectomy through several portals has been advocated as an alternative to arthrotomy, there is a significant risk of inadequate excision and recurrence, particularly in the posterior compartment of the knee. For local disease partial arthroscopic synovectomy may be sufficient, at the risk of recurrence. For both local and diffuse intra-articular disease open surgery is advised for recurrent disease. Marginal excision with focal disease will suffice, not dissimilar to the treatment of GCT of tendon sheath. For recurrent and extra-articular soft-tissue disease adjuvant therapy, including intra-articular radioactive colloid or moderate-dose external beam radiotherapy, should be considered.

We report our experience of treating 17 patients with benign lesions of the proximal femur with non-vascularised, autologous fibular strut grafts, without osteosynthesis. The mean age of the patients at presentation was 16.5 years (5 to 33) and they were followed up for a mean of 2.9 years (0.4 to 19.5). Histological diagnoses included simple bone cyst, fibrous dysplasia, aneurysmal bone cysts and giant cell tumour. Local recurrence occurred in two patients (11.7%) and superficial wound infection, chronic hip pain and deep venous thrombosis occurred in three. Pathological fracture did not occur in any patient following the procedure.

We conclude that non-vascularised fibular strut grafts are a safe and satisfactory method of treating benign lesions of the proximal femur.

We report our early experience with a new peri-acetabular reconstruction endoprosthesis used for pelvic reconstruction after tumour resection. The outcome of 21 patients who underwent limb salvage following type II pelvic resection and reconstruction using the peri-acetabular reconstruction prosthesis between 2000 and 2006 was retrospectively reviewed. This prosthesis was designed to use the remaining part of the ilium to support a horizontally placed acetabular component secured with internal fixation and bone cement. Into this device a constrained acetabular liner is positioned which is articulates with a conventional femoral component to which a modular extension and modular head are attached. The mean follow-up was 20.5 months (1 to 77). The most common complications were deep infection, superficial wound infections, and dislocation. The mean musculoskeletal tumor society functional outcome score for the survivors was 20.1(11 to 27).

We recommend the use of the peri-acetabular reconstruction prosthesis for reconstruction of large defects after type II pelvic resection, as this design has a greater inherent stability over other available prostheses.

We identified 42 patients who presented to our unit over a 27-year period with a secondary radiation-induced sarcoma of bone. We reviewed patient, tumour and treatment factors to identify those that affected outcome. The mean age of the patients at presentation was 45.6 years (10 to 84) and the mean latent interval between radiotherapy and diagnosis of the sarcoma was 17 years (4 to 50). The median dose of radiotherapy given was estimated at 50 Gy (mean 49; 20 to 66). There was no correlation between radiation dose and the time to development of a sarcoma. The pelvis was the most commonly affected site (14 patients (33%)). Breast cancer was the most common primary tumour (eight patients; 19%). Metastases were present at diagnosis of the sarcoma in nine patients (21.4%). Osteosarcoma was the most common diagnosis and occurred in 30 cases (71.4%). Treatment was by surgery and chemotherapy when indicated: 30 patients (71.4%) were treated with the intention to cure. The survival rate was 41% at five years for those treated with the intention to cure but in those treated palliatively the mean survival was only 8.8 months (2 to 22), and all had died by two years. The only factor found to be significant for survival was the ability to completely resect the tumour. Limb sarcomas had a better prognosis (66% survival at five years) than central ones (12% survival at five years) (p = 0.009).

Radiation-induced sarcoma is a rare complication of radiotherapy. Both surgical and oncological treatment is likely to be compromised by the treatment received previously by the patient.

A retrospective analysis was performed of eight patients with an open triradiate cartilage, who underwent resection for osteosarcoma and reconstruction of the proximal femur with a hemiarthroplasty, in order to identify changes of acetabular development. An analysis of the centre-edge angle, teardrop-to-medial prosthesis distance, superior joint space, teardrop-to-superior prosthesis distance, degree of lateral translation, and arthritic changes, was performed on serial radiographs. The median age at the time of the initial surgery was 11 years (5 to 14).

All patients developed progressive superior and lateral migration of the prosthetic femoral head. Following hemiarthroplasty in the immature acetabulum, the normal deepening and enlargement of the acetabulum is arrested. The degree of superior and lateral migration of the prosthetic head depends on the age at diagnosis and the length of follow-up.