Advances in modular endoprosthetic reconstruction of osseous defects

Purpose of review: Reconstruction of segmental skeletal defects after resection of tumors remains a technically challenging procedure. Recent advances and improvements in modular endoprosthetic systems have led to an increased acceptance of this form of reconstruction. Results of recent publications and presentations are summarized. Recent findings: The advent of modular, off-the-shelf components that are assembled during the surgical procedure has virtually replaced the use of custom implants in a majority of patients. Recent reports from large institutions demonstrate the durability of these modular systems, which significantly outperform the older generation of custom implants. Further developments have expanded the indications for modular reconstruction to include anatomically challenging sites such as the shoulder and pelvic girdle, and the skeletally immature patient. Summary: In addition to reconstruction of segmental defects after tumor resection, modular endoprostheses are increasingly used for complicated revisions of the hip and knee after failed total joint replacement. Complications, although less frequent than with custom implants, can often be successfully managed with additional surgery. Further work in reducing the risk of periprosthetic infection and aseptic loosening will advance this growing field

Reconstruction of hip stability after proximal and total femur resections

Dislocation is the most common complication after proximal and total femur endoprosthetic reconstruction. The current study describes a surgical technique of acetabular preservation and reconstruction of the joint capsule and abductor mechanism that recreates joint stability and avoids dislocation. Between 1980 and 1996, 57 patients underwent proximal or total femur resection with endoprosthetic reconstruction. Forty-six patients had primary sarcoma of bone, nine had other bone tumors, and two had metabolic bone disease. The acetabulum was spared and not resurfaced in all patients. Bipolar hemiarthroplasty was performed in 49 patients, and fixed unipolar hemiarthroplasty was performed in eight. Soft tissue reconstruction included Dacron tape capsulorrhaphy over the prosthetic neck, reattachment of the abductor mechanism to the prosthesis, and extracortical bone fixation. The average followup period was 6.5 years (range, 2-18.2 years). Dislocation occurred in only one (1.7%) patient, and aseptic prosthetic loosening occurred in thee (5.3%) patients. Four patients with primary bone sarcoma had local recurrence, of whom one required amputation of the limb. The limb salvage rate was 98%. Eighty-one percent of the patients had a good to excellent functional outcome. Acetabular preservation, capsulorrhaphy, and reconstruction of the abductor mechanism recreate hip stability and avoid dislocation after proximal and total femur endoprosthetic reconstruction

Giant Cell Tumor of the Pes Anserine Bursa (Extra-Articular Pigmented Villonodular Bursitis): A Case Report and Review of the Literature

Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferating disease affecting the synovium of joints, bursae, and tendon sheaths. Involvement of bursa (PVNB, pigmented villonodular bursitis) is the least common, and only few cases of exclusively extra-articular PVNB of the pes anserinus bursa have been reported so far. We report a case of extra-articular pes anserine PVNB along with a review of the literature. The lesion presented as a painful soft tissue mass in the medial part of the proximal leg. A magnetic resonance imaging showed areas of low to intermediate signals in all sequences and the lesion enhanced heterogeneously with contrast. Diagnosis was confirmed by an incisional biopsy, and an intralesional resection was performed. The postoperative course was uneventful, and the patient is free of disease with no functional deficit at 2 years followup. As with other rare lesions, clinical and radiographic findings in addition to histological examination are essential for correct diagnosis

The percutaneous needle biopsy is safe and recommended in the diagnosis of musculoskeletal masses: Outcomes analysis of 155 patients at a sarcoma referral center

BACKGROUND. The purpose of this study was to analyze the role of percutaneous core needle biopsy in the diagnosis of musculoskeletal sarcomas. METHODS. One hundred eighty-five biopsy procedures were performed on 161 musculoskeletal tissue masses suspected of being a sarcoma in 155 patients who underwent subsequent tumor resection. A percutaneous core needle biopsy was performed on all masses either in the clinic or under radiologic guidance. If an adequate diagnosis could not be made on the basis of this biopsy specimen, an open incisional biopsy was performed. RESULTS. One hundred seventy-three core needle biopsy procedures were performed: 90 without radiologic guidance, 55 computed tomography guided, and 28 fluoroscopically guided. Twelve open incisional biopsies were performed. Eightythree sarcomas, 67 benign mesenchymal tumors, and 11 metastatic epithelial tumors were identified. Analysis of the data reveals that only 7.4% of the masses required open biopsy. In 88.2% of the masses, a single percutaneous biopsy procedure was adequate, and no additional biopsy was necessary. There was a 1.1% rate of complications; none caused a change in the patient\u27s treatment plan. There was a 1.1% rate of major diagnostic errors, none of which ultimately impacted on the patient\u27s outcome. There were no unnecessary amputations. Percutaneous needle biopsy showed a positive predictive value of 100%, a negative predictive value of 82%, a sensitivity of 81.8%, and a specificity of 100%. The accuracy of a single-needle biopsy procedure to identify benign versus malignant lesions, exact grade, and exact pathology was 92.4%, 88.6%, and 72.7%, respectively. CONCLUSIONS. The percutaneous needle biopsy was found to be extremely effective and safe for the diagnosis of musculoskeletal masses. This method allowed 88% of patients with suspected sarcomas to undergo a single-needle biopsy procedure before the initiation of definitive treatment. Patients undergoing percutaneous needle biopsy had lower rates of major diagnostic errors and complications than previously described for open biopsy. Open biopsy offered limited additional information when preceded by a needle biopsy, given that these tumors were difficult to identify even after final resection. © 2000 American Cancer Society

All-trans retinoic acid and interferon-α in the treatment of a patient with resistant metastatic osteosarcoma: A case report

BACKGROUND. A boy age 14 years who was in complete remission from Stage IIB small cell osteosarcoma, which was misdiagnosed as Ewing sarcoma and consequently was treated, developed inoperable lung metastases when he was off therapy. He received second-line treatment for recurrent Ewing sarcoma, including chemotherapy and radiotherapy, and obtained only a temporary response. A compassionate treatment with all-trans retinoic acid (ATRA) and interferon-α (IFNα) was then undertaken. METHODS. The patient initially was treated according to the national SE91 protocol for nonmetastatic Ewing sarcoma. After a bilateral pulmonary recurrence, he received second-line chemotherapy and irradiation of the largest metastasis, with a temporary partial response. The patient was then treated with a combination of oral ATRA (90 mg/m2 for 3 days per week) and subcutaneous IFNα (3 × 106 U/m2 5 days per week) for 4 months. The same therapy also was administered for the control of residual disease after surgery for a total duration of 1 year of ATRA/IFN treatment. During the first 3 weeks of therapy, ATRA pharmacokinetics were studied. RESULTS. After progression of the patient\u27s disease, despite the administration of first-line and second-line chemotherapy, combined treatment with ATRA/IFNα yielded a partial remission, which allowed surgical resection of the largest metastasis. The same therapy was effective in preventing tumor recurrence after incomplete removal of the remaining metastases. Treatment was well tolerated, and the patient is in stable complete remission 14 months after the end of therapy. The pharmacokinetics results confirmed the indication of an intermittent schedule for oral ATRA therapy. CONCLUSIONS. ATRA/IFNα treatment may be considered as an alternative approach in the treatment of patients with metastatic osteosarcoma who have disease that is resistant to conventional chemotherapy and in the treatment of patients with minimal tumor residue. © 2000 American Cancer Society

Implant Design and Resection Length Affect Cemented Endoprosthesis Survival in Proximal Tibial Reconstruction

Endoprosthetic reconstruction of the proximal tibia continues to pose many challenges. A retrospective analysis of 44 consecutive patients who underwent cemented proximal tibial replacement were included to investigate if patient age, surgical stage, type of implant, stem diameter, or resection length could be associated with implant failure. Fifteen patients (34%) suffered prosthetic failure, 7 due to infection. Prosthetic-related complications occurred in 13 patients (30%). Custom design prosthesis and longer length of resection were significantly associated with prosthesis survival in a Cox regression analysis (P = .001, hazard ratio = 8.747 and P = .044, hazard ratio = 1.217, respectively). Cemented proximal tibial replacement offers a functional knee, but reducing risk of complications still remains challenging. Prosthetic design and length of resection affect overall cemented endoprosthesis survival. © 2008 Elsevier Inc. All rights reserved