The stability of the hip after the use of a proximal femoral endoprosthesis for oncological indications: analysis of variables relating to the patient and the surgical technique.

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. PATIENTS AND METHODS: In a retrospective cohort study, we identified 527 adult patients who were treated with a PFA for tumours. Our data included demographics, the pathological diagnosis, the amount of resection of the abductor muscles, the techniques of reconstruction and the characteristics of the implant. We used regression analysis to compare patients with and without post-operative instability. RESULTS: A total of 20 patients out of 527 (4%) had instability which presented at a mean of 35 days (3 to 131) post-operatively. Capsular repair was not associated with a reduced rate of instability. Bivariate analysis showed that a posterolateral surgical approach (odds ratio (OR) 0.11, 95% confidence interval (CI) 0.02 to 0.86) and the type of implant (p = 0.046) had a significant association with reduced instability; age > 60 years predicted instability (OR 3.17, 95% CI 1.00 to 9.98). Multivariate analysis showed age > 60 years (OR 5.09, 95% CI 1.23 to 21.07), female gender (OR 1.73, 95% CI 1.04 to 2.89), a malignant primary bone tumour (OR 2.04, 95% CI 1.06 to 3.95), and benign condition (OR 5.56, 95% CI 1.35 to 22.90), but not metastatic disease or soft-tissue tumours, predicted instability, while a posterolateral approach (OR 0.09, 95% CI 0.01 to 0.53) was protective against instability. No instability occurred when a synthetic graft was used in 70 patients. CONCLUSION: Stability of the hip after PFA is influenced by variables associated with the patient, the pathology, the surgical technique and the implant. We did not find an association between capsular repair and improved stability. Extension of the tumour often dictates surgical technique; however, our results indicate that PFA using a posterolateral approach with a hemiarthroplasty and synthetic augment for soft-tissue repair confers the lowest risk of instability. Patients who are elderly, female, or with a primary benign or malignant bone tumour should be counselled about an increased risk of instability. Cite this article: Bone Joint J 2017;99-B:531-7.

EURAMOS-1, an international randomised study for osteosarcoma: results from pre-randomisation treatment.

BACKGROUND: Four international study groups undertook a large study in resectable osteosarcoma, which included two randomised controlled trials, to determine the effect on survival of changing post-operative chemotherapy based on histological response. PATIENTS AND METHODS: Patients with resectable osteosarcoma aged ≤40 years were treated with the MAP regimen, comprising pre-operatively of two 5-week cycles of cisplatin 120 mg/m(2), doxorubicin 75 mg/m(2), methotrexate 12 g/m(2) × 2 (MAP) and post-operatively two further cycles of MAP and two cycles of just MA. Patients were randomised after surgery. Those with ≥10% viable tumour in the resected specimen received MAP or MAP with ifosfamide and etoposide. Those with <10% viable tumour were allocated to MAP or MAP followed by pegylated interferon. Longitudinal evaluation of quality of life was undertaken. RESULTS: Recruitment was completed to the largest osteosarcoma study to date in 75 months. Commencing March 2005, 2260 patients were registered from 326 centres across 17 countries. About 1334 of 2260 registered patients (59%) were randomised. Pre-operative chemotherapy was completed according to protocol in 94%. Grade 3-4 neutropenia affected 83% of cycles and 59% were complicated by infection. There were three (0.13%) deaths related to pre-operative chemotherapy. At definitive surgery, 50% of patients had at least 90% necrosis in the resected specimen. CONCLUSIONS: New models of collaboration are required to successfully conduct trials to improve outcomes of patients with rare cancers; EURAMOS-1 demonstrates achievability. Considerable regulatory, financial and operational challenges must be overcome to develop similar studies in the future. The trial is registered as NCT00134030 and ISRCTN 67613327.

Classification of failure of limb salvage after reconstructive surgery for bone tumours : a modified system Including biological and expandable reconstructions.

Previous classification systems of failure of limb salvage focused primarily on endoprosthetic failures and lacked sufficient depth for the effective study of the causes of failure. In order to address these inadequacies, the International Society of Limb Salvage (ISOLS) formed a committee to recommend revisions of the previous systems. The purpose of this study was to report on their recommendations. The modifications were prepared using an earlier, evidence-based model with subclassification based on the existing medical literature. Subclassification for all five primary types of failure of limb salvage following endoprosthetic reconstruction were formulated and a complementary system was derived for the failure of biological reconstruction. An additional classification of failure in paediatric patients was also described. Limb salvage surgery presents a complex array of potential mechanisms of failure, and a complete and precise classification of types of failure is required. Earlier classification systems lacked specificity, and the evidence-based system outlined here is designed to correct these weaknesses and to provide a means of reporting failures of limb salvage in order to allow the interpretation of outcome following reconstructive surgery.

Efficacy of NovoSeven during surgery on a haemophiliac with previous history of inhibitors.

Management of bleeding in haemophiliacs with a history of inhibitor remains problematic. With infusion of factor VIII (FVIII), development of an anamnestic response and possible appearance of high-titre inhibitor remains a valid concern. We report a case of a haemophiliac with a history of moderately high-titre FVIII inhibitor that had become undetectable. He had not received FVIII since 1997, when he became inhibitor negative. He had been managed during his bleeding episodes with prothrombin complex factor concentrates, which became less effective in controlling his bleeding. The patient had a history of recurrent, spontaneous shoulder joint dislocations with bleeding, pain and significant disability. Shoulder joint replacement surgery was suggested. Replacement therapy was discussed with the patient, who refused treatment with human FVIII because of his concern for possible anamnestic response and inhibitor rebound. Porcine FVIII was not acceptable due to his poor response when used once in the past, and his history of moderate allergic reaction. Therefore, recombinant factor VIIa (NovoSeven, Novo Nordisk, Princeton, NJ) was considered to be an acceptable option for the contemplated shoulder surgery. The patient underwent 2.5 h of surgery with NovoSeven infusion. The surgeons were impressed with the lack of bleeding in this traumatic surgery. Despite the continuously prolonged activated partial thromboplastin time and low FVIII levels, the patient maintained a remarkably dry surgical field. Effective haemostasis was achieved during and after this procedure. This case illustrates the usage of NovoSeven as an effective treatment modality in a haemophilia A patient with past history of inhibitor undergoing joint surgery.

Modular endoprostheses for children with malignant bone tumors.

BACKGROUND: The treatment of malignant bone tumors in skeletally immature patients is difficult because the required surgery removes the growth plate of one extremity. To date, few techniques for limb salvage have been successful due to complications involving limb expansion and limb-length discrepancy. Newer technology is now available for prosthetic replacements for modular expansion. METHODS: The authors review current surgical treatment of malignant bone tumors in children, with emphasis on reconstruction with expandable modular prostheses, and they present their own experience. RESULTS: Thirty-seven children with malignant bone tumors underwent primary tumor resection and reconstruction with a modular prosthetic device. Fourteen had subsequent successful expansions with modular prostheses. A new prosthesis, in which lengthening is achieved by an external electromagnetic field rather than an open surgical procedure, is discussed. CONCLUSIONS: Limb-preserving surgery in children with malignant bone tumors can be accomplished successfully with modern prosthetic devices that have expandable modules within them. The technique of expandable prostheses using electromagnetic fields rather than surgical interventions shows promise.

Genetic and molecular abnormalities in tumors of the bone and soft tissues.

BACKGROUND: Malignant transformation requires the accumulation of multiple genetic alterations such as chromosomal abnormalities, oncogene activation, loss of tumor suppressor genes, or abnormalities in genes that control DNA repair and genomic instability. Sarcomas are a heterogeneous group of malignant mesenchymal tumors of difficult histologic classification and strong genetic predisposition. This article provides a comprehensive review of the cytogenetic abnormalities observed in bone and soft-tissue tumors, emphasizing known downstream molecular changes that may play a role in oncogenesis. METHODS: The database of the National Library of Medicine was searched for literature relating to genetic and molecular mechanisms in sarcomas in general and in each of the main tumor entities. RESULTS: Recent techniques in chromosome analysis and molecular cytogenetics have improved our ability to characterize genetic changes in mesenchymal tumors. Some changes are so characteristic as to be virtually pathognomonic of particular histologic types, while others are complex, difficult to characterize, and of unknown relevance to pathogenesis. The implications to the cell of some of these abnormalities are now being recognized. CONCLUSIONS: The study of sarcomas will benefit from the information derived from genetic studies and translational research. The human genome project and new methodologies, such as computer-based DNA microarray, may help in the histogenetic classification of sarcomas and in the identification of molecular targets for therapy.

Gastrointestinal stromal tumors.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. A relationship to the interstitial cells of Cajal (ICCs) has been proposed, and expression of CD117, the c-kit receptor present in ICCs, has been suggested as a marker for GISTs. METHODS: The English literature has been reviewed with an emphasis on histogenetic features, especially the potential relationship of GISTs to ICCs. RESULTS: GISTs are most common in the stomach (70%), followed by small intestine (20%), colon and rectum (5%), and esophagus (<5%). GISTs commonly have activating mutations in exon 11 (or rarely exon 9 and exon 13) of the KIT gene that encodes a tyrosine kinase receptor for the stem cell factor or mast cell growth factor. CONCLUSIONS: Malignant potential is best estimated by the simultaneous evaluation of several clinical parameters. The only absolute criterion for malignancy is tumor spread beyond the organ of origin at the time of diagnosis. The remarkable clinical response of tumors that express c-kit to treatment with the tyrosine kinase inhibitor STI571 is a triumph of molecular pharmacology.

Hyperthermic isolated limb perfusion for extremity sarcomas.

BACKGROUND: The treatment options available for extremity sarcomas are amputation or limb-sparing surgery with radiation, which may incur significant morbidity and body disfigurement. Hyperthermic isolated limb perfusion (HILP) may be an attractive option in extremity sarcomas for unresectable lesions to preserve limb function and maintain quality of life. METHODS: We report the outcomes of 5 patients who underwent HILP for unresectable primary or recurrent extremity sarcomas from 1994 to 2000 at our institution. RESULTS: All patients had initial complete clinical responses to HILP, and the limb was salvaged in 4 of the 5 patients. Complications included chronic lymphedema, neuropathic pain, and prolonged wound healing. CONCLUSIONS: HILP with melphalan is a safe and effective treatment option for selected patients with locally advanced and unresectable extremity sarcomas. The response rates are high, with limb salvage occurring in most patients. Further studies of larger groups of patients are warranted.

Appropriate follow-up of orthopaedic oncology patients.

In summary, there is no gold standard of the appropriate follow-up of orthopaedic patients. Patients with musculoskeletal neoplasms should be watched closely for local recurrence. Those patients whose tumors have metastatic potential should be followed up closely for metastatic disease. The timing of the suggested follow-up intervals varies, depending on the aggressiveness and growth rate of the tumor. There is no objective, data-based study to define the optimal follow-up intervals for the various entities. In general, the earlier recurrent or progressive disease can be detected, the better the chance of disease eradication. However, there is still some question as to whether the earlier detection of metastatic disease will change the eventual outcome in these patients.

Activity relationships of total hip arthroplasty in patients with osteonecrosis and osteoarthritis.

We compared the age adjusted results of all primary Osteonics total hip arthroplasties with osteonecrosis and osteoarthritis. The Harris index hip score was used for the analysis. Twenty-eight patients had osteoarthritis and 26 patients had osteonecrosis. The Harris hip score was used to compare the osteoarthritis and osteonecrosis gross. Patients with osteoarthritis gradually increased in Harris hip score, whereas osteonecrosis patients gradually decreased in Harris hip score over 60 months. However, after the patients were adjusted for age above and below 50 years, the trend for each group was similar despite the diagnosis. All patients below 50 years of age, regardless of diagnosis, gradually decreased in hip score over time. On the other hand, all patients over 50 had a gradual increase in hip score with time. The poor results seen in patients with osteonecrosis may be related more to age and activity level than to the primary diagnosis. We do not believe that the diagnosis of osteonecrosis plays as significant a role in the final outcome of a total hip arthroplasty as does the patient's age and, more importantly, activity level following hip arthroplasty.

Evaluation of the child with a bone or soft-tissue neoplasm.

The prebiopsy evaluation of a child with a musculoskeletal neoplasm is the cornerstone for all subsequent treatment. A better understanding of the natural history of pediatric musculoskeletal tumors and an explosion in the development of sensitive new imaging modalities have significantly advanced the care of the child with a musculoskeletal pathologic condition. This article details the prebiopsy clinical and radiographic evaluation of the child or adolescent with a musculoskeletal neoplasm.

Osteochondritis dissecans.

Osteochondritis dissecans were recognized many years ago, but its cause remains debatable. In a case of osteochondritis dissecans in a 24-year-old black man, hemosiderin was found in the loose body that was removed from the patient's knee. The presence of hemosiderin supports injury as the cause, but the patient had no history to indicate injury was a factor.