Marginal resection as a potential curative treatment option of infantile fibrosarcoma with good response after chemotherapy: A case report of an ETV6-NTRK3 positive infantile fibrosacroma of the distal tibia.

RATIONALE: The infantile fibrosarcoma (IFS) is a non-rhabdomyosarcoma soft tissue sarcoma with locally aggressive properties. State of the art therapy consists of neoadjuvant chemotherapy followed by wide resection according to the criteria of the musculoskeletal tumor society. DIAGNOSES: An ETV6-NTRK3 positive IFS of the distal tibia in a 21-months old child showed good response to chemotherapy. INTERVENTIONS: Due to refusal of amputation marginal resection completing the margins with a high speed drill and filling the space with bone cement was performed. OUTCOMES: At latest follow-up 10 years after surgery, no recurrence was observed. LESSONS: An individual therapy for surgical treatment of IIFS is recommended. This comprises marginal resection in instead of the golden standard "wide resection" in selected cases.

How Relevant Is the Parallax Effect on Low Centered Pelvic Radiographs in Total Hip Arthroplasty.

The correct cup position in total hip arthroplasty (THA) is usually assessed on anteroposterior low centered pelvic radiographs, harboring the risk of misinterpretation due to projection of a three-dimensional geometry on a two-dimensional plane. In the current study, we evaluate the effect of this parallax effect on the cup inclination and anteversion in THA. In the course of a prospective clinical trial, 116 standardized low centered pelvic radiographs, as routinely obtained after THA, were evaluated regarding the impact of central beam deviation on the cup inclination and anteversion angles. Measurements of the horizontal and vertical beam offset with two different methods of parallax correction were compared with each other. Furthermore, the effect of parallax correction on the accuracy ofmeasuring the cup position was investigated. The mean difference between the two parallax correction methods was 0.2° ± 0.1° (from 0° to 0.4°) for the cup inclination and 0.1° ± 0.1° (from -0.1° to 0.2°) for the anteversion. For a typically intended cup position of a 45° inclination and 15° anteversion, the parallax effect led to a mean error of -1.5° ± 0.3° for the inclination and 0.6° ± 1.0° for the anteversion. Central beam deviation resulted in a projected higher cup inclination up to 3.7°, and this effect was more prominent in cups with higher anteversion. In contrast, the projected inclination decreased due to the parallax effect up to 3.2°, especially in cups with high inclination. The parallax effect on routinely obtained low centered pelvic radiographs is low and not clinically relevant due to the compensating effect of simultaneous medial and caudal central beam deviation.

SOX9 Knockout Induces Polyploidy and Changes Sensitivity to Tumor Treatment Strategies in a Chondrosarcoma Cell Line.

As most chemotherapeutic drugs are ineffective in the treatment of chondrosarcoma, we studied the expression pattern and function of SOX9, the master transcription factor for chondrogenesis, in chondrosarcoma, to understand the basic molecular principles needed for engineering new targeted therapies. Our study shows an increase in SOX9 expression in chondrosarcoma compared to normal cartilage, but a decrease when the tumors are finally defined as dedifferentiated chondrosarcoma (DDCS). In DDCS, SOX9 is almost completely absent in the non-chondroid, dedifferentiated compartments. CRISPR/Cas9-mediated knockout of SOX9 in a human chondrosarcoma cell line (HTB94) results in reduced proliferation, clonogenicity and migration, accompanied by an inability to activate MMP13. In contrast, adhesion, apoptosis and polyploidy formation are favored after SOX9 deletion, probably involving BCL2 and survivin. The siRNA-mediated SOX9 knockdown partially confirmed these results, suggesting the need for a certain SOX9 threshold for particular cancer-related events. To increase the efficacy of chondrosarcoma therapies, potential therapeutic approaches were analyzed in SOX9 knockout cells. Here, we found an increased impact of doxorubicin, but a reduced sensitivity for oncolytic virus treatment. Our observations present novel insight into the role of SOX9 in chondrosarcoma biology and could thereby help to overcome the obstacle of drug resistance and limited therapy options.

[Bone cysts-differential diagnosis and therapeutic approach]. / Knochenzysten ­ Differenzialdiagnose und therapeutisches Vorgehen.

The differential diagnosis of cystic lesions of the skeleton is multifarious. Besides patient age, the localization and radiologic morphology provide important information for a closer differentiation. Juvenile and aneurysmal bone cysts represent two frequent entities in growing patients. The fluid content of the cysts helps in distinguishing between juvenile and aneurysmal bone cysts. Whereas juvenile bone cysts contain clear fluid, the content of aneurysmal bone cysts consists of blood combined with solid tissue. With respect to progression, aneurysmal bone cysts show a higher activity than solitary bone cysts. The treatment of juvenile bone cysts usually consists of curettage including filling with bone replacement material. For aneurysmal bone cysts the additional use of adjuvants is recommended. Bone cement is preferably used for filling. It shows favorable properties for prophylaxis of recurrence and facilitates the recognition of relapses. Both juvenile and aneurysmal bone cysts often show recurrences.

Changes in physical activity and health-related quality of life during the first year after total knee arthroplasty.

OBJECTIVE: Despite its impact on the overall outcome and health-related quality of life (HRQOL) after knee surgery, physical activity has not been investigated directly using accelerometry or step monitoring during the first year after total knee arthroplasty (TKA) due to osteoarthritis (OA). Therefore, the present study aimed to evaluate the development of physical activity over 12 months after surgery and its relationship to clinical outcome and HRQOL. METHODS: Fifty-three patients scheduled for primary TKA due to OA were measured with the DynaPort ADL monitor and a step activity monitor preoperatively and at 2, 6, and 12 months of followup. Clinical outcome and HRQOL were investigated using the American Knee Society Score (KSS) and Short Form 36 (SF-36) health survey. RESULTS: Physical activity increased significantly within 12 months of followup (from mean ± SD 4,993 ± 2,170 gait cycles preoperatively to 5,932 ± 2,111 gait cycles; P = 0.003). Clinical outcome and HRQOL improved from baseline (mean ± SD KSS 88.9 ± 21.4, mean ± SD SF-36 43.1 ± 18.4) to 12 months of followup (mean ± SD KSS 188.6 ± 10.9; P = 0.001 and mean ± SD SF-36 82.5 ± 15.9; P = 0.001). Physical activity parameters did not correlate with clinical outcome. CONCLUSION: TKA offers profound improvements of physical activity for the majority of patients. Despite these improvements and the excellent clinical outcome, most patients do not reach the level of physical activity reported for healthy subjects. The activity level after treatment seems to be influenced by physical activity behavior prior to surgery rather than by the treatment itself.

Walking ability during daily life in patients with osteoarthritis of the knee or the hip and lumbar spinal stenosis: a cross sectional study.

BACKGROUND: Degenerative musculoskeletal disorders are among the most frequent diseases occurring in adulthood, often impairing patients' functional mobility and physical activity. The aim of the present study was to investigate and compare the impact of three frequent degenerative musculoskeletal disorders--knee osteoarthritis (knee OA), hip osteoarthritis (hip OA) and lumbar spinal stenosis (LSS)--on patients' walking ability. METHODS: The study included 120 participants, with 30 in each patient group and 30 healthy control individuals. A uniaxial accelerometer, the StepWatch™ Activity Monitor (Orthocare Innovations, Seattle, Washington, USA), was used to determine the volume (number of gait cycles per day) and intensity (gait cycles per minute) of walking ability. Non-parametric testing was used for all statistical analyses. RESULTS: Both the volume and the intensity of walking ability were significantly lower among the patients in comparison with the healthy control individuals (p < 0.001). Patients with LSS spent 0.4 (IQR 2.8) min/day doing moderately intense walking (>50 gait cycles/min), which was significantly lower in comparison with patients with knee and hip OA at 2.5 (IQR 4.4) and 3.4 (IQR 16.1) min/day, respectively (p < 0.001). No correlations between demographic or anthropometric data and walking ability were found. No technical problems or measuring errors occurred with any of the measurements. CONCLUSIONS: Patients with degenerative musculoskeletal disorders suffer limitations in their walking ability. Objective assessment of walking ability appeared to be an easy and feasible tool for measuring such limitations as it provides baseline data and objective information that are more precise than the patients' own subjective estimates. In everyday practice, objective activity assessment can provide feedback for clinicians regarding patients' performance during everyday life and the extent to which this confirms the results of clinical investigations. The method can also be used as a way of encouraging patients to develop a more active lifestyle.

Sports activities and endurance capacity of bone tumor patients after rotationplasty.

OBJECTIVES: To investigate the preferred types of sports activities of patients with rotationplasty and to measure their physiologic performance characteristics through treadmill ergometry. DESIGN: Cross-sectional, descriptive analysis and repeated measures of different velocities. SETTING: Biomechanics research laboratory. PARTICIPANTS: Patients (n=61) with rotationplasty after bone tumor surgery, 30 of whom participated in a functional trial (treadmill), and a control group (n=20). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients' participation in sports compared with that of the healthy population, treadmill performance at 2 or 3 different speeds, heart rate, lactate accumulation, oxygen consumption, ventilatory equivalent, efficiency, respiratory minute volume, and respiratory quotient. RESULTS: High activity in sports participation (85%) in most common sports (8 competitive, 17 sports club members, the remaining subjects were recreational athletes). At the same treadmill speed, lactate accumulation and all cardiorespiratory functions were higher in rotationplasty patients than in the control group. CONCLUSIONS: Patients can re-engage in a high level of physical activity after rotationplasty for bone tumor treatment. This physical activity is necessary if patients want to maintain or improve a desired level of sports activity.

Changes in talocrural joint contact stress characteristics after simulated rotationplasty.

In order to assess the changes in talocrural joint contact stress after rotationplasty, 10 lower-leg cadaver specimens were axially loaded with 600 N and investigated in two loading situations: (1) Normal loading with a plantigrade foot; (2) in an equinus position of a simulated rotationplasty. Joint contact stress in the talar facet of the talocrural joint was determined with Fuji Prescale film cut to size and analyzed with digital image analysis for joint contact area, mean and peak pressure, contact force, and location of the load application on the trochlea tali. The results demonstrate a significant transfer on the loading zone to the posterior part of the talus (p = 0.005), a significant reduction of the contact area (p = 0.005) and force (p = 0.005), and a significant increase of the mean (p = 0.022) and maximum pressures (p = 0.013). These results indicate that the rotationplasty causes pronounced changes in joint loading characteristics.

Giant cell tumor of the spine.

Six patients with giant cell tumor of the spine had surgery between 1981 and 1995. Three lesions were located in the scrum, two lesions were in the thoracic spine, and one lesion was in the lumbar spine. Preoperatively, all patients had local pain and neurologic symptoms. Two patients had cement implanted after curettage or intralesional excision of the sacral tumor; one patient had a local relapse. After the second curettage and cement implantation, the tumor was controlled. One patient with a sacral lesion had marginal excision and spondylodesis; no relapse developed. Two patients with thoracic lesions had planned marginal excision and spondylodesis; the margins finally became intralesional, but no relapse developed. One patient with a lumbar lesion had incomplete removal of the tumor and received postoperative irradiation. At the final followup (median, 69 months), five of six patients were disease-free and one patient died of disease progression. Two of the five surviving patients had pain after standing or neurologic problems. Although some contamination occurred, planning a marginal excision of the lesion seems beneficial for vertebral lesions above the sacrum. Total sacrectomy of a sacral lesion seems to be too invasive when cement implantation can control the lesion.

Osteoid osteoma and osteoblastoma of the spine: experiences with 22 patients.

Osteoblastomas and osteoid osteomas of the spine are relatively rare bone-forming tumors. Between 1980 and 1999, nine patients with osteoid osteoma and 13 patients with osteoblastoma had surgery for their tumors. Four tumors were in the cervical spine, six tumors were in thoracic spine, 10 tumors were in the lumbar spine, and two tumors were in the sacrum. The average duration between onset of pain and surgery was 16.6 months in 12 patients treated in the 1980s and 8.6 months in 10 patients treated in the 1990s. Seventeen patients had scoliosis. In nine of 10 patients with magnetic resonance imaging scans, high signal intensity areas in the muscles and bone around the lesion were seen. Two of nine patients with osteoid osteoma and nine of 13 patients with osteoblastoma had neurologic disorders before treatment. All patients had open resection of the lesions. Two patients with osteoid osteoma had relapse because of incomplete resection, necessitating a second excision. In 16 of 17 patients with preoperative spinal deformity, the deformity improved during followup. With development of modern imaging techniques, exact surgical planning may become possible; however, in some cases, intraoperative complete resection of the lesion still is difficult.

Osteosarcoma of the spine: experience of the Cooperative Osteosarcoma Study Group.

BACKGROUND: Due to the low incidence rate, the optimal strategy for the treatment of patients with spinal osteosarcoma is unknown. METHODS: Twenty-two patients with osteosarcoma of the spine (15 with tumors of the sacrum and 7 with tumors at other sites) who received chemotherapy according to the Cooperative Osteosarcoma Study Group protocol were analyzed. Six patients presented with metastasis, and 16 patients had no evidence of metastasis at the time of entry into the protocol. Of 12 patients who underwent excision of their tumors, 2 patients underwent wide excision, 3 patients underwent marginal excision, and 7 patients underwent intralesional excision. Eight patients received irradiation: Six patients received conventional radiotherapy only, one patient received neutron beam therapy, and one patient received samarium-153-ethylene diamine tetramethylene phosphonate therapy. Follow-up ranged between 24 months and 105 months (median, 47 months). RESULTS: The median survival was 23 months, and three patients have survived without disease for > 6 years. Patients with primary metastases (P = 0.004), large tumors (P = 0.010), and sacral tumors (P = 0.048) had lower overall survival compared with patients who had no metastasis, small tumors, and nonsacral tumors, respectively. There was a significant difference in overall survival between 5 patients who underwent either wide or marginal surgery and 17 patients who underwent either intralesional surgery or no surgery (P = 0.033). Among 17 patients who underwent no surgery or intralesional surgery, overall survival tended to be better in 7 patients who received irradiation compared with the overall survival in 10 patients who did not receive irradiation (P = 0.059). CONCLUSIONS: Patients with metastases, a large tumors, and sacral tumors had a poor prognosis in the current study with small numbers of patients. Wide or marginal excision of the tumor improved survival. Patients with osteosarcoma of the spine should be treated with a combination of chemotherapy and at least marginal excision for those with surgically accessible tumors. Postoperative radiotherapy may be beneficial.

Implantation of hemipelvic prosthesis after resection of sarcoma.

Twelve adult patients with pelvic sarcoma had implantation of a hemipelvic prosthesis. Eight patients had hemipelvic resection, and four patients had acetabulopubic resection. The implanted prosthesis was a special Vitallium prosthesis, which was specially designed for each patient with the aid of a computer. At a median followup of 57 months, eight patients were free of disease. In four patients with local relapse, two had additional resection, one had hindquarter amputation, and one was observed. In three patients with deep infection, the prosthesis was removed; however, one patient had hindquarter amputation. One patient had dislocation of the hip and prosthesis loosening. Overall survival of patients was 70%, and the survival of prostheses was 42%. In eight patients, the functional evaluation showed that the average functional score with the prosthesis was 11.6 (39%) and without the prosthesis the functional score was 7.0 (23%). Implantation of a megaprosthesis seems to indicate a high complication rate and a poor functional result after hemipelvic resection.