Prosthetic replacement after resection of osteosarcoma of the proximal femur: a case report

¹Department of Orthopedic Surgery, Sahloul University Hospital, Sousse, Tunisia

^&Corresponding author
Ahmed Trabelsi, Department of Orthopedic Surgery, Sahloul University Hospital, Sousse, Tunisia

Introduction    

Osteosarcoma is the most common malignant bone tumor, twice as much as chondrosarcoma [1]. Their preferential locations are the metaphysis of the following long bones: the distal femur (40%), proximal tibia (16%) and proximal humerus (15%) [2]. The proximal femur is reached in less than 5% by doing a very rare pathology [3]. Involvement of the proximal femur is a very unusual location, which may be responsible for delay in diagnosis and inadequate management. Before the 1970s, the treatment of this tumor consisted of amputation as soon as diagnosis was established with an early survival of less than 20% [4], but its prognosis has been modified by the introduction of chemotherapy and multidisciplinary care in specialized centers involving the oncologist, the orthopedic surgeon, the radiologist, and the histologist, and the current focus of surgical treatment is conservative surgery. We report a patient who presented with osteosarcoma of the proximal femur with intra-articular invasion. We describe the technique of resection of the proximal femur with reconstruction using a total hip prothesis with long stem, and we will demonstrate through the clinical evolution, the interest of conservative treatment when associated with a well-adapted adjuvant treatment.

Patient and observation     

Patient information: a 20-year-old male patient, originally from a neighboring country, non-smoker, non-alcoholic, no family history of cancer. Consulted us for hip pain, limping and weight loss. He was initially explored by another team, who performed a percutaneous but inconclusive biopsy.

Clinical findings: the patient presents with amyotrophy of the right gluteal region, pain and stiffness on hip mobilization, collateral venous circulation, and a scar from the previous percutaneous biopsy.

Timeline of current episode: June 2016, biopsy of a condensed image of the upper end of the right femur in Algeria (Figure 1). October 2016 first magnetic resistance imaging, body CT scan and a bone scintigraphy were carried out. In november 2016, a new biopsy was performed by our team via an external crural approach. December 2016, patient referred to the carcinology team for neoadjuvant chemotherapy, during this period, the patient had a right femoral neck fracture stabilized by Bermuda plaster. In mars 2017, a new radiological evaluation was doing, MRI of the pelvis and a body CT scan.

Diagnostic assessment: the magnetic resonance imaging shows an infiltrative and aggressive intraosseous tissue process involving the epiphyseal metaphysis region of the proximal right femur stretched 10 cm in height with cortical intrusion and intra-articular invasion (Figure 2). The extension assessment found bone metastasis at L4 level and multiple pulmonary nodular lesions. The histological examination of the biopsy performed by our team shows a malignant tumor proliferation of a sarcomatous nature made up of widely polymorphous, rounded, ovoid, elongated, polygonal and oval cells with eosinophilic cytoplasm and enlarged, hyperchromatic nucleus, nucleolated with numerous mitosis figures. In some areas, these cells are in contact with chondroid tissue or bone maturation sites. In other sites, the proliferation is fibroblastic. The cells are arranged in clusters interspersed and separated by sclerohyaline remodeling areas. The bone maturation is chondroid. The tumor proliferation is mainly in bone samples. Fibroblastic maturation is mainly involved in soft tissue infiltration.

Diagnosis: the histological examination and the radiological results were consistent with the diagnosis of osteosarcoma of the proximal right femur with pulmonary and vertebral metastasis. During neoadjuvant chemotherapy, the patient had a right femoral neck fracture stabilized by Bermuda plaster.

Therapeutic interventions: the patient is treated according to the OS 2006 protocol, preoperative chemotherapy was administered consisting of, adriamycin 60 mg/m²/d and ifosfamide 3 g/m²/d once every 3 weeks for a total of 5 administrations, with this the patient also received cisplatinium 100 mg/m²/d once every 6 weeks for 3 administrations in total. Then, despite the increase in the number of pulmonary nodules and the non-regression of the tumor size, we opted for a 20 cm high resection of the proximal femur followed by a total hip prothesis with long stem (Figure 3, Figure 4). Histological examination showed a necrosis rate of more than 90% and a resection limit classified R0.

Follow-up and outcome of interventions: after adjuvant chemotherapy using the same protocol, and at two years of follow-up, the evolution was marked by the stabilization of the vertebral lesion and pulmonary nodular lesions with a satisfactory functional result (Figure 5).

Patient perspective: I am satisfied with the treatment despite the side effects of the chemotherapy, and I am happy to have preserved my limb.

Informed consent: the authors have obtained the patient´s informed written consent for print and electronic publication of this case report.

Discussion     

Osteosarcoma usually occurs in the metaphysis of long bones, particularly the distal femur, in 40% of cases [2]. Localization at the proximal femur is rare [5]. Other lesions that commonly involve the proximal femur include benign lytic lesions such as essential bone cyst and fibrous dysplasia, as well as chondroblastoma, whose far greater frequency may therefore provide the clinician with unwarranted reassurance. Articular cartilage constitutes an anatomic barrier to tumor invasion, and the extension of the hip joint by lesions of the proximal femur is rare [6]. Prosthetic replacement is a good option for reconstruction after resection of a proximal femur osteosarcoma due to its low complication rate and a good functional result [7]. However, the incorrect placement of a total hip prosthesis leads to dissemination of the joint and the soft parts around the femur [1]. Bielack et al. [2] in a study of 1702 patients from the Cooperative Osteosarcoma Study Group, reported that the location of osteosarcoma in the proximal femur was associated with the highest rate of local recurrence of long bone damage and that proximal extremity impairment was associated with lower survival compared to distal impairment. Philippe Anract et al [8] recommend acetabular resection in case of articular invasion. They describe several methods used for reconstruction after acetabular resection such as, homolateral proximal femoral autograft and total hip prosthesis, saddle prosthesis, Mac Minn prosthesis with auto or allograft, modular prosthesis or custom-made prosthesis, massive allograft with or without prosthesis and femoro-ilac arthrodesis. After resection of the iliac wing plus acetabulum, reconstruction can be performed, according to them [8], by femoro-obturator and femoral-sacral arthrodesis, homolateral proximal femoral autograft and prosthesis or by femoral medialization and massive allograft. In our case it seems that the good response to chemotherapy has allowed a good evolution and a stabilization of the metastatic lesion, even though we have not opted for an extra-articular resection of the acetabulum recommended by several authors.

Conclusion     

Treatment of osteosarcoma of proximal femur requires multidisciplinary management. Appropriate and effective neoadjuvant and adjuvant chemotherapy is essential for the success of conservative surgical treatment. Our clinical case shows that prosthetic replacement has its place in the surgical treatment of osteosarcoma of proximal femur, even at the stage of metastasis.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Patient management: Adnan Siala and Mehdi Jedidi. Data collection: Ahmed Trabelsi, Lassaad Hassini and Mohamed Ali Khalifa. Manuscript drafting: Ahmed Trabelsi. Manuscript revision: Karim Bouattour. All the authors have read and agreed to the final manuscript.

Figures     

Figure 1: standard antero-posterior radiograph of the pool, June 2016; (A) osteo-condensing lesion of the femoral neck and head (red arrow); B) pathway of the old biopsy (black arrow)

Figure 2: coronal and sagittal MRI demonstrating the extent of the lesion; (A,B) aggressive infiltrative intraosseous tissue process involving the diaphyseal-metaphyseal region of the proximal end of the right femur with signs of cortical effraction and a periosteal sunburst reaction (red arrow)

Figure 3: approach for the tumor resection and the prosthetic replacement; wide external approaches with excision of the biopsy path

Figure 4: two years post-operative radiograph; no radiological evidence of local metastasis, total hip replacement with a long stem locked in place

Figure 5: (A,B) photos at last follow-up showing good functional result; clean scar, no disunion or fistula, stable right monopodal support

References