The retrospective collection of clinical data and the publication of the data were in accordance with local guidelines for research ethics and were approved by the research ethics committee of General Hospital of Ji’Nan Military Region, Ji’Nan. All patients were treated by the same chief surgeon (XCY) and his assistants (SFX and MX) in the same institute. Written informed consent for participation in the study was obtained from all patients, including permission to access patient records and to publish individual clinical details. All procedures were in compliance with the Helsinki Declaration.
We retrospectively reviewed 51 patients who underwent limb-salvage surgery of osteosarcoma in distal femur at our institution, and were at least 12 years old at the time of operation. All patients received a diagnosis of osteosarcoma by biopsy and pathology. The surgery had been carried out between May 1995 and November 2012.
There were 30 males and 21 females with an average age of 21 years (range 13–51 years). 47 were under 30 years. One patient was with lung node and the other one with lung metastasis diagnosed by biopsy. No patients were with pathological fracture.
Preoperative chemotherapy was performed 2 times on a neoadjuvant basis. Two chemotherapy protocols were used: the DIA [2] and MMIA protocols [3]. Evidence of good chemotherapeutic response consisted of sclerotic changes or good margin of the tumor observed on plain radiographs, marked shrinkage of tumors extending into soft tissue on MR images.
Operative treatment
Surgical technique followed standard oncologic principles of segmental resection as previously described [4]. Alcohol-inactivated autograft replantation was used in selective cases. Ligaments and tendons were reattached if possible, but this varied on a case-by-case basis. 10 patients had experienced alcohol-inactivated autograft replantation with articulation preservation, and 11 experienced alcohol-inactivated bone replantation without articulation preservation. Internal plate, screw, and intramedullary nail were used as internal fixations in inactivated autograft replantation [5]. The other 30 patients had experienced custom-made rotating hinged knee prosthesis (LiDaKang, BeiJing, China) replacement.
The conventional anterormedial incision encircling the biopsy scar for the knee was used. The surgical technique, taking the inactivated autograft replantation with articulation preservation as a sample, was described as follows [6]: (1) The lesion in distal femur was resected according to tumor-free technique rules at least 1 cm over tumor boundary, and the distal articular surface below Insall line was preserved according to preoperative MRI. (2) Then soft tissue and extraosseous tumor were cleared off. The medullar cavity was reamed and intraosseous tumor was curetted. (3) Preliminary screw fixation was prepared. The prepared autograft was then immerged into 99% alcohol for 30 minutes, retrieved and flushed with 3000 ml physiological saline. (4) The intramedullary nail was inserted into the inactivated bone off the table by carefully pressurizing cement into the inactivated bone, using the operator’s thumb to occlude the proximal medullar canal. Any excess cement was removed from the protruding stem of the femoral component and from the distal end of the inactivated bone. (5) After cylindrical reaming of the proximal femur, the intramedullary nail was inserted and cemented. (6) Before polymerization of the cement, the inactivated autograft was fixed quickly into the distal preserved articular surface with screws through previously prepared cross screw route. Care was taken so no cement was caught between the inactivated autograft and the host bone. If possible, it is recommended that autogenous iliac bone grafts were placed at the inactivated autograft-host bone junction to form extracortical grafting.
Tumor location
Tumor location in distal femur was classified into 3 types by the extension of osteosarcoma according to preoperative MRI (Figure 1). The extension of the tumor was evaluated on T1-weighted, T2-weighted, and Gd-enhanced T1-weighted MRI images in coronal, sagittal, and axial planes.
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1.
Type IType I tumors were those located in the diaphysis at a distance of ≥ 1 cm from the Insall line. There were 8 patients with this type (Figure 2). Reconstruction in 7 patients was performed using inactivated autograft replantation with articulation preservation, and in 1 patient diagnosed as parosteal osteosarcoma without neoadjuvant chemotherapy using inactivated autograft replantation without articulation preservation.
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2.
Type IIType II tumors were those located in contact with the Insall line or within 1 cm from this line. There were 14 patients with this type (Figure 3). Reconstruction in 3 patients was performed using inactivated autograft replantation with articulation preservation (Figure 4), and in 9 patients using inactivated autograft replantation without articulation preservation. In the other 2 patients with severe bone destruction, the custom-made rotating hinged knee prosthesis was used.
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3.
Type IIIType III tumors were those extending from the diaphysis to the epiphysis beyond the Insall line. This type was the most frequently observed (29 patients) (Figure 5). Reconstruction was performed using the custom-made rotating hinged knee prosthesis in all patients, one of whom was with lung metastasis.
Postoperative treatment
Prophylactic antibiotics were administered for 48 hours. Low-molecular-weight heparin was administered for 2 weeks in prosthesis group and none in inactivated-replantation group. For postoperative treatment, patients in prosthesis group were placed on bed for 1 week without external brace and in inactivated-bone group on bed for 6 weeks with external brace. After that, partial weight bearing was allowed initially, and then weight-bearing using two elbow crutches was allowed. Full weight bearing with no support was allowed at the end of 3 months in prosthesis group and 6 months in inactivated-replantation group. Plain anteroposterior and lateral radiographic examinations were done every 3 months for two years, bi-annually for a further three years and annually thereafter.
Except one who refused chemotherapy administration, all were administered chemotherapy 6 times postoperatively with two protocols: the DIA and MMIA protocols [3].
Functional assessment
Limb function was evaluated with the Musculoskeletal Tumor Society (MSTS) rating scales, which comprise seven items, namely motion, pain, stability, deformity, strength, functional activity and emotional acceptance. The highest possible score is 35 and 5 points being allocated to each item [7]. According to the follow-up period, it was divided into ≤2-year group and >2-year group.
Quality of life assessment
The Quality of Life (QOL)—modified specific scale for Chinese cancer patient [2] is a 12-item questionnaire that measures quality of life (appetite, sleep quality, pain, daily life condition, facial expressions, adverse reactions, fatigue, spiritual well-being, cancer knowledge, attitude to treatment, understanding and cooperation of family members and colleagues). Each item is rated on a 5-point Likert-type scale. The total score is 60. The results are ≤ 20 (very poor), 21–30 (poor), 31–40 (fair), 41–50 (good), and 51–60 (very good). High scores indicate good quality of life. According to the follow-up period, it was divided into ≤2-year group and >2-year group.
Statistics
Summary statistics were calculated for patient characteristics by type and reconstruction groups. Chi-square tests of independence were used to assess group differences in sex and race. Median tests were used to assess group differences in age at diagnosis, duration from diagnosis to study participation, and age at the time of study participation. Means, standard deviations (SDs), and confidence intervals were calculated for each functional and psychological outcome variable by type and reconstruction groups. Multiple linear regression models were used to examine differences in functional and psychological outcomes among the three patient groups and three type groups after adjusting for duration from diagnosis to study participation.