Intramedullary Well-Differentiated Osteosarcoma: Imaging and Pathologic Findings in 17 Patients

Background: Intramedullary well-differentiated osteosarcoma (IMWDOS) is rare and may easily be misdiagnosed. Objective: This study was to investigate the clinical, imaging and pathological features of IMWDOS for correct diagnosis. Results: There were 13 males and 4 females with an age range of 19-55 years (mean 32). The lesion was located at long bones in 16 patients and at the second region of acetabulum in one patient. Except for three patients with limited areas of lesions, all the other patients had wide areas of disease, and the lesion in long bones all involved the metaphysis area with possible extension towards the diaphysis. In imaging, the lesion usually had an unclear boundary with destruction of bone cortex, uneven thickness of the bone cortex, thick and coarse trabecula in the lesion, but few periosteal reaction and soft tissue masses. The lesion was histologically composed of spindle cells with slight atypia. Follow-up was performed 2-101 months (mean 37.7) in 14 cases, 10 years in one case and 26 years in the remaining two. At follow-up, 12 patients (12/17 or 70.6%) who had complete resection including amputation (n=2), wide excision (n=8) and endoprosthetic replacement (n=2) had no recurrence or metastasis. Among five patients with curettage, three (3/17 or 17.6%) were recurrent with two deaths, and the third one died during post-operation chemotherapy. Conclusion: Intramedullary well-differentiated osteosarcoma tends to occur at the metaphysis of long bones, especially at the distal femur. Histological, clinical and imaging findings lack characteristics and should be closely combined to reach a correct diagnosis. The prognosis of patients with complete lesion resection is good while incomplete lesion curettage or resection will lead to recurrence and transformation into a highly malignant tumor.

Femoral bone growth after extendible endoprosthetic replacement of the proximal tibia in skeletally immature patients

There is increasing preference for limb salvage techniques in the management of pediatric musculo- skeletal tumors. This study was aimed at evaluating femoral growth following proximal tibia resection (PTR) and placement of an extendible endoprosthesis with sliding stem. This was a retrospective study. The demographic and clinical data were collected. All the patients with malignant tumors were fully staged and commenced on appropriate chemotherapy. An expected discrepancy of > 3cm was considered sub- stantial enough to warrant extendible prosthesis. Twelve patients who had follow up full length scanogram of the lower limbs were included for the evaluation of femoral growth. The last available scanograms were used for growth comparison of the femur. The age at resection for all twelve patients ranged from 4-13 years. The commonest histological diagnosis was Osteosarcoma. In the twelve patients assessed for the growth of femur, the mean femoral length was 96% [89%-102%] of the unaffected femur. Distal femoral physeal growth continued after im- plantation of a sliding extendible prosthesis after resection of proximal tibia tumors.

Implant survival and functional results of endoprosthetic reconstruction for proximal femoral metastases with pathological fractures

Background: This study aimed to evaluate the patient and implant survival, clinical and functional outcomes, and the rate of complications resulting in reconstruction failure following endoprosthetic reconstruction (EPR) of extensive proximal femoral metastases associated with actual or impending pathological fractures. Methods: A total of 111 patients with actual or impending pathological fractures due to metastatic disease of the proximal femur were treated with EPR between 2003 and 2018. Staged surgery, bilateral EPR, was performed in 3 cases. The patients comprised 51 females and 60 males with a mean age of 52.1 ± 12.3 years. The patient and implant survival were recorded. Clinical and functional outcomes were assessed by using the visual analogue scale (VAS), Musculoskeletal Tumour Society (MSTS) functional scoring, and Karnofsky Performance Scale (KPS). The different types of abductor mechanism repair were evaluated by functional tests and existence of Trendelenburg gait at postoperative follow-ups. The complications resulting in reconstruction failure were investigated. Results: The mean follow-up was 23.1 ± 17.9 months. The overall survival of patients after EPR was 89% at 6 months, 72% at 1 year and 10% at 5 years. The estimated 1- and 5-year overall implant survival was 100% and 97.3% (95% CI, 0.95–0.98), respectively, as the endpoint was defined as complete removal of the prosthesis. Median VAS score before endoprosthetic replacement was 8 and after 3 months 4. Before surgery, the median MSTS score was 40 (30–56.6%) and the median KPS score was 40 (30–50). Postoperative third month, the median MSTS score was 56.6 (53.3–86.6%) and the median KPS score was 60 (40–70). Functional scores were superior in trochanter major split osteotomized group compared to trochanter major removed group. Trendelenburg gait was seen in 20 (17.5%) patients postoperatively. There were 10 (8.7%) complications resulting in reconstruction failure. Conclusion: Endoprosthetic replacement can provide a durable fixation with high implant survival rate and good clinical and functional results in extensive proximal femoral metastases associated with a pathological fracture.

Modular endoprosthetic replacement for proximal tibia tumor patients

The major method of malignant bone tumors treatment is surgery. The most important task of an orthopedic surgeon is to preserve an adjacent joint. Currently, there are a large number of various reconstructive surgeries, including structural bone allograft, allocomposite and modular endoprosthetics replacement. The aim: to analyze the results of surgical treatment for proximal tibia malignant tumors using modular endoprosthesis. Materials and methods. The results of proximal tibia (PT) modular endoprosthetic replacement in 48 patients with PT tumor lesions were evaluated. The patients were divided into two groups: I (n = 36) – tumor resection and primary modular endoprosthesis, II (n = 12) – revision modular endoprosthetic replacement due to complications. Complications were divided into oncological, mechanical and non-mechanical. The functional outcomes were measured using the MSTS and TESS scores. Results. During the treatment, 10 (21.2 %) patients underwent myofascioplastic amputation at the middle third of the thigh: due to periprosthetic infection – 8 people and tumor recurrence – 2. It was found that the patients got back to regular way of life on average in 2.0–2.5 months. Functional results on the MSTS score were 73 ± 12 %, on the TESS score – 74 ± 16 %, which corresponds to good functional results. Among the patients, who underwent limb salvage surgery, no tumor recurrence was detected during a follow-up period from 6 months up to 11 years. Conclusions. The choice of surgical treatment depends on the size of tumor, its location, pathohistomorphological picture, age, presence of pathological fractures, vascular and nerve tumor invasion. The use of modern designs of PT modular tumor endoprostheses and perfect surgeries makes it possible to minimize complications.

Radiation-induced pathological fractures of the proximal femur: a case series considering an endoprosthetic solution

ABSTRACT BACKGROUND: Radiation-induced pathological fractures of the proximal femur are difficult to treat due to frequent non-union and hardware failure using standard fracture fixation techniques. This case series investigates endoprosthetic replacement as a treatment option METHODS: A retrospective folder review from a private hospital in Cape Town, of patients who had sustained a radiation-induced pathological fracture, was reviewed using descriptive statistics. RESULTS: Six patients met the inclusion criteria. One patient was excluded as the minimum follow-up time of six months was not met. Of the Ave patients that were analysed, all Ave sustained transverse, subtrochanteric femur fractures. Prior to definitive treatment with a proximal femoral replacement, three patients were treated with standard trauma instrumentation prior to referral to the unit, and one patient was treated with a vascularised fibular graft as their initial treatment while at the unit. One patient was treated with an endoprosthetic replacement as their first procedure at the unit. Among the three patients treated with standard trauma fixation and the one patient treated with a vascularised fibular graft, there was a 100% failure rate. One standard trauma instrumentation patient had an ablation due to free musculocutaneous flap failure and periprosthetic infection after endoprosthetic replacement. This was the only complication of endoprosthetic replacement. At a median follow-up of 15 months (min 7, max 55) the median Musculoskeletal Tumour Society score was 74% (min 63%, max 93%. CONCLUSION: This case series seeks to highlight the high failure rates seen when treating this condition with standard trauma instrumentation or biological methods. Further research is needed, but endoprosthetic replacement may be a viable alternative solution Level of evidence: Level 4. Keywords: radiation-induced fracture, pathological fracture, endoprosthetic replacement