Abstract：Pulmonary metastasectomy is an important curative option for patients with osteogenic and softtissue sarcoma spread to the lungs. Complete surgical removal of pulmonary metastases can improve survival and is recommended under certain criteria. Specific issues that require consideration when planning pulmonary metastasectomy include: preoperative assessment of the operation index and contraindications, choice of surgical strategies, pulmonary parenchymal preservation, and the role of lymphadenectomy. With the development of iconography and chemotherapy, the emergence of targeted drugs, and the innovation of radiotherapy, the concept of the diagnosis and treatment for pulmonary metastases from osteogenic and softtissue sarcoma is also undergoing great changes.
Objective To investigate the clinical application and early results of combined epiphyseal preservation and autograft bone transfer for limb salvage in children with osteosarcoma. Methods Between March 2010 and March 2011, 3 children with osteosarcoma were treated with epiphyseal preservation and autograft bone transfer. There were 1 boy and 2 girls with the age of 10-14 years. The disease duration was 2 weeks to 3 months. The tumors were rated as type II according to San-Julian radiological classification and as type IIB according to Enneking surgical classification. The locations were the distal femur in 1 case and the proximal tibia in 2 cases. The surgical technique included preoperative neoadjuvant chemotherapy, excision of part of the epiphysis, preservation of subarticular epiphysis, external fixation with Ilizarov apparatus and transport osteogenesis treatment. Safe excision border was confirmed by histological examination. Postoperative observation included the wound healing, local recurrence or distant metastasis, length, speed, alignment, and regeneration of transplanted bone, the length and function of the affected limb. Results The postoperative histological examination proved the safe surgical margin in all 3 patients. The incision healing by first intention was obtained at distal femur in 1 case and by second intention at proximal tibia in 2 cases at 4 weeks after changes of dressing. Three patients were followed up 12, 18, and 24 months, respectively. There was no local recurrence or distant metastasis during follow-up. Two cases had pin-tract infection at 10 months after external fixation and were cured after changes of dressing and antibiotics administration. The length of transplanted osteogenisis was 18.0, 9.5, and 16.0 cm, respectively. The speed of lengthening was 2.57, 2.07, and 1.20 cm/month, respectively. One patient had alignment deviation during lengthening, which was adjusted under anaesthesia. Bony healing was achieved at 8 months after lengthening end in 2 cases and external fixation was removed; 1 patient had poor bone growth and was given retraction for promoting bone growth. At last follow-up, the length of the affected limbs was 1.0-1.5 cm shorter than that of normal limbs, but no abnormalities was observed at donor sites. The affected knee flexion reached 90° and 120° in 2 patients and poor knee function was observed in 1 patient for external fixation. Conclusion The combined epiphyseal preservation and transport osteogenesis technique can be used for bone defect repair by lengthening the residual bone. It is a promising limb salvage treatment for children with osteosarcoma.
Objective To analyze the effectiveness and application value of epiphysis preserving by the method of physeal distraction for treatment of femur osteosarcoma in children’s limb saving surgery. Methods Between January 2007 and January 2011, 6 patients with femur osteosarcoma underwent epiphysis preserving operation by physeal distraction. There were 4 males and 2 females with a mean age of 11.4 years (range, 9-14 years). The mean disease duration was 4.8 months (range, 1-9 months). The pathology confirmed osteosarcoma in all patients by core needle or open biopsy, including 1 case of osteogenic sarcoma, 1 case of chondroblastic osteogenic sarcoma, 1 case of osteoblastic osteogenic sarcoma, and 3 cases of no classified osteosarcoma. The clinical stage was IIA in 1 case and IIB in 5 cases according to the Enneking staging system. All patients received 2 cycles of neoadjuvant chemotherapy before operation. Then physeal distraction was performed for 4-7 days (mean, 5.7 days) based on Cantilde;adell technique. After 1-2 days of physeal distraction, massive allograft bones and interlocking intramedullary nails were used to reconstruct bone defect after tumor resection. All patients received another 4-6 cycles of chemotherapy and were followed up. Bone healing, limb discrepancy, and complications were recorded. Functional outcomes were assessed by the system of the Musculoskeletal Tumor Society (MSTS) and the range of motion (ROM) of both knee joints. Results Superficial infection occurred in 1 case and was cured after dressing change, and primary healing was obtained in the other patients. All 6 patients were followed up 2.5 years on average (range, 1-5 years). Symptoms of pain and swelling disappeared. No complication of allograft rejection, loosening or breaking of fixation occurred. No relapse or metastasis happened during follow-up. Bone healing was observed at the metaphysis junction in 5 cases at 6-9 months after operation and in 1 case at 14 months. Delayed union happened at the diaphysis junction in all patients. Different amount of callus formation was seen at the surface of diaphysis junction, but the fracture line remained clear at 12-48 months after operation. At last follow-up, limb discrepancy was 1-3 cm in 4 patients and 3-5 cm in 2 patients; 3 patients had compensatory scoliosis, and 2 patients had claudication. The MSTS score was 27.20 ± 1.92, showing significant difference (t= — 4.12, P=0.00) when compared with preoperative score (19.60 ± 2.74). The ROM of affected knee was (127.00 ± 17.89)°, showing no significant differences when compared with preoperative ROM (109.00 ± 12.45)° (t= — 1.84, P=0.10) and with ROM of normal knee (126.00 ± 9.62)° (t= — 0.11, P=0.92). Conclusion Limb saving surgery by physeal distraction can be used in young patients with open epiphyseal plate, which has the advantages of simple operation, good effectiveness, and less complications.
Objective To investigate the feasibility of the preservation of the epiphysis and joint function of the distal femur in children with osteosarcoma with epiphyseal distraction by external fixator. Methods Between July 2007 and May 2011, 6 children with osteoblastic osteosarcoma of the distal femur underwent epiphyseal distraction by external fixator, combined with tumor resection and repair with massive allograft bone transplantation to preserve the epiphysis and joint function of the distal femur. There were 4 boys and 2 girls, aged from 9 to 14 years (mean, 10.5 years). According to Enneking clinical staging, 4 cases were in stage II A and 2 cases in stage II B. According to San-Julian et al. typing for metaphyseal tumor invasion, 3 cases were in type I and 3 cases in type II. The size of tumor ranged from 6 cm × 4 cm to 12 cm × 9 cm. All patients received 2 cycles of COSS 86 chemotherapy before operation and 4 cycles after operation. Results Poor healing of incision was observed in 1 case because of rejection of allograft bone and good healing was obtained after the symptomatic treatment, healing of incision by first intention was achieved in the other children. All 6 cases were followed up 11 to 56 months (mean, 37.5 months). One case died of lung metastasis at 2 years after operation. X-ray films showed no complication of internal fixator loosening and broken or bone nonunion. According to the functional evaluation criteria of International Society of Limb Salvage (ISOLS) at last follow-up, the results were excellent in 3 cases, good in 2 cases, and fair in 1 case; the excellent and good rate was 83.3%. The length of operated limb was (62.97 ± 7.51) cm, showing significant difference when compared with that of normal limb [(64.03 ± 7.47) cm] (t=0.246 6, P=0.813 4). Conclusion On the premise of adaptable indication, effective chemotherapy, and thoroughly tumor resection, the epiphyseal distraction by external fixator can obtain satisfactory results in limb-length and limb function in children with osteoblastic osteosarcoma of the distal femur.
Objective To review the research progress of the treatment of osteosarcoma, and to thoroughly understand its current state of research and prospect so as to lay a sol id foundation for the cl inical treatment. Methods The cl inical and experimental research l iteratures about treatment of osteosarcoma were extensively reviewed and analyzed. Results The present treatment of osteosarcoma is still need to comprehensive therapy which combine chemotherapy and surgical treatment. There are some progresses in gene therapy and molecular targeting therapy which can improve survival rate. Furthermore, well-designed studies and cl inical trials are needed to evaluate the potential therapeutic impact before they are used in cl inical. Conclusion Advancement in chemotherapeutic regimens has improved survival and l imb-sparing surgery in the treatment of osteosarcoma, but the progress of gene therapy and molecular targeting therapy gives new hope for osteosarcoma patients.
Objective To design, construct and select the optimal repl ication-defective recombinant adenovirus mediated short hairpin RNA (shRNA) which is transduced into human osteosarcoma cells to silence c-myc gene expression, and to construct the recombinant adenovirus vector expressing c-myc-shRNA and determine its viral titer. Methods Three pairs of complementary single-stranded ol igonucleotides (ss ol igos) were designed and synthesized, and then they were annealed to create a double-stranded ol igonucleotide (ds ol igos).The ds ol igos were cloned into pENTR/U6 vector to produce the shuttle plasmid pENTR/U6-shRNA, which was transduced into osteosarcoma cells by l iposome after sequencing. The plasmid with good silence effect was chosen by RT-PCR to perform the LR recombination reaction to the adenovirus backbone plasmid. The expression clone was transfected into HEK293A cells to produce repl ication-incompetent recombinant adenovirus mediated shRNA against c-myc whose cytopathic effect was observed and viral titer was determined by the viral particle (VP) method and 50% tissue culture infective dose (TCID50). Results Ds ol igos, which was verified by electrophoresis, was cloned into pENTR/U6 vector to produce pENTR/U6-shRNA shuttle plasmid, which was confirmed to be corrected by sequencing. The optimal plasmid with good silence effect was chosen by RT-PCR from the three pairs of double-stranded ol igonucleotide. By Pac I enzyme, the l inearrization repl ication-defective recombinant adenovirus mediated shRNA was constructed to perform the LR recombination reaction to the adenovirus backbone plasmid. The cytopathic effect and vacuole phenomenon of adenovirus mediated shRNA appeared at 3 days and became obvious at 6 days. The adenovirus virus titer in the first generation was 5.23 × 109 VP/mL, and reached 2.26 × 1012 VP/mL via 3-4 generations’ ampl ification. The viral titer was 10-3.8/0.1 mL determined by VP method and TCID50. Conclusion The recombinant adenovirus mediated shRNA c-myc is constructed in vitro through RNA interference technology.
Objective To investigate the effect of limb salvage on treating osteosarcoma with pathological fracture. Methods From October 2002 to January 2003, 2 cases of osteosarcoma with pathological fracture were treated by limb salvage. Intraarterial chemotherapy was given by subcutaneous implantable delivery system with caffeine. Replacement with prosthesis was performed after 5 times of chemotherapy. Results Two patients were followed up for twenty-four months and 21 months respectively. No infection, aseptic loosening, local recurrence or metastasis occurred, and function recovery of joints was satisfactory. Conclusion Limb salvage can be considered in condition that primary osteosarcoma with pathological fracture can be treated by effective and comprehensive chemotherapy.