OBJECTIVE: To investigate the effectiveness of three-dimensional (3D) printed customized hemi-pelvic prosthesis for pelvic reconstruction after resection of massive pelvic tumors. METHODS: A retrospective analysis was conducted on 26 patients with massive pelvic tumors who met the selection criteria and were treated between November 2021 and May 2024. The cohort included 11 males and 15 females, with a mean age of 52.65 years (range, 17-73 years). Histopathological diagnoses were as follows: 9 cases of chondrosarcoma, 2 of undifferentiated pleomorphic sarcoma, 4 of spindle cell sarcoma, 2 of osteosarcoma, 1 of solitary fibrous tumor, 1 of myxoid chondroma, 1 of malignant peripheral nerve sheath tumor, 1 of chondromyxoid epithelioma, and 5 of metastatic malignant tumors. According to the Enneking classification, tumor involvement was distributed as 4 cases in zones Ⅰ+Ⅱ, 9 in zones Ⅱ+Ⅲ, 3 in zones Ⅰ+Ⅳ, 8 in zones Ⅰ+Ⅱ+Ⅲ, and 2 in zones Ⅰ+Ⅱ+Ⅳ. The disease duration ranged from 3 to 40 months, with a mean of 9.85 months. All patients underwent reconstruction with customized 3D-printed hemi-pelvic prostheses. The effectiveness was evaluated by Musculoskeletal Tumor Society (MSTS) score and Harris hip score before operation and at last follow-up, and pain levels were evaluated by visual analogue scale (VAS) score before operation, at 3 months after operation, and at last follow-up. RESULTS: The operation time ranged from 186 to 528 minutes, with a mean of 334.58 minutes. The intraoperative blood loss ranged from 1 400 to 4 000 mL, with a mean of 2173.08 mL, and the transfusion volume ranged from 750 to 3 500 mL, with a mean of 1 659.62 mL. All 26 patients were followed up 10-42 months (mean, 18.5 months). Postoperative complications included prosthetic dislocation in 2 cases, which were attributed to improper positioning during home care and an accidental fall, respectively. One patient developed a vesicocutaneous fistula and poor wound healing due to pre-existing tumor invasion into the bladder. One patient experienced failure and loosening of the internal fixation at 8 months after operation caused by local tumor recurrence, and subsequently died at 14 months postoperatively due to progression of brain metastases. Postoperative complications such as poor healing of incisions, prosthetic dislocation, or failure of internal fixation was not observed in the remaining patients. At last follow-up, the walking ability of most patients recovered to varying degrees. The VAS scores at 3 months and at last follow-up significantly improved when compared with those before operation, and the scores at last follow-up further improved when compared with 3 months after operation, all showing significant differences ( P<0.05). The MSTS scores and Harris scores at last follow-up were significantly higher than those before operation ( P<0.05). CONCLUSION 3D printed customized hemi-pelvic prosthesis is effective for reconstruction of massive pelvic tumors after resection, but there are still some limitations, and soft tissue reconstruction should be paid attention to.
Humans ; Printing, Three-Dimensional ; Female ; Male ; Adult ; Plastic Surgery Procedures/methods* ; Retrospective Studies ; Middle Aged ; Aged ; Pelvic Bones/surgery* ; Bone Neoplasms/surgery* ; Adolescent ; Pelvic Neoplasms/surgery* ; Prosthesis Design ; Young Adult ; Treatment Outcome ; Prostheses and Implants

The adjacent anatomy of the pelvis is complicated, with digestive, urinary, reproductive and other organs as well as important blood vessels and nerves. Therefore, accurate resection of pelvic tumors and precise reconstruction of defects after resection are extremely difficult. The development of medical 3D printing technology provides new ideas for precise resection and personalized reconstruction of pelvic tumors. The “triune” application of 3D printing personalized lesion model, osteotomy guide plate and reconstruction prosthesis in pelvic tumor limb salvage reconstruction treatment has achieved good clinical results. However, the current lack of normative guidance standards such as preparation and application of 3D printing personalized lesion model, osteotomy guide plate and reconstruction prosthesis restricts its promotion and application. The formulation of this consensus provides normative guidance for 3D printing personalized pelvic tumor limb salvage reconstruction treatment.

Objective To study the feasibility and safety of total en bloc spondylectomy (TES) for bone tumors of the fourth lumbar spine and evaluate the clinical outcomes.Methods From March 2011 to December 2013,21 patients undergone total en bloc spondylectomy in posterior-only approach were retrospectively reviewed.The patients included 9 males and 12 females,with a mean age of 47.1± 15.6 years old (range,15-71 years old).This series included 12 cases of primary bone tumors and 9 cases of solitary metastases.Preoperative evaluation according to clinical,imaging and pathologic features was performed meticulously to select patients.The length of surgery,estimated blood loss,surgical margins,instrumentation failure,perioperative complications,Frankel scale,visual analogue scale (VAS) for pain,local control rate and overall survival were reviewed and analyzed.Results Total en bloc spondylectomy was performed successfully in all patients.Average operative time and estimated blood loss were 297.6±44.6 min (range,225-420 min) and 2 247.1±904.5 ml (range,900-4100 ml),respectively.The mean follow-up time was 50.4± 17.1 mons (range,24-79 mons).All patients encountered nerve roots stretch and 5 patients (23.8％) showed lower extremeties neurological dysfunction.All of them improved in 2-4 weeks postoperatively and recovered completely at 6-month follow -up.Cerebrospinal fluid leak was found in 4 patients (19.0％).The VAS score was 1.5±1.4 at post-operation,which was significantly lower than the 6.2± 1.6 in average at operation (P=0.008).Three patients with metastatic tumors died during the follow-up.Titanium mesh cage subsidence was observed in 7 patients (33.3％).No implant failure was occurred during the follow-up.Conclusion Total en bloc spondylectomy for tumors of the fourth lumbar spine in a posterior-only approach is feasible.However,there are many intraoperative neurological complications and the indications for TES are extremely limited.

Objective To investigate the safety and feasibility of en-bloc resection of a primary sacral chordona based on a 3-dimensional printing model.Methods 31 patients with primary sacral chordoma underwent en-bloc resection via a onestage posterior approach or combined anterior and posterior approaches in our oncology department from January 2013 to December 2014.They comprised 21 males and 10 females of mean age (49.2±12.5) years (range,26-67 years).Preoperative 3-D printing models were created by 3D printing technology,it included tumor tissue,the around vascular and nerves involved in sacral chordoma.The sacral chordomas were en-bloc resection with decompression and internal fixation.Results With the mean (29.0±6.8)months follow-up (range from 19 to 41),all patients underwent en bloc excision via 26 cases with posterior approach,5 cases combined posterior and anterior approaches in one stage.The mean operative time and estimated blood loss were (275.0±58.1) min and (3 250.0±1 304.4) ml,respectively.The visual analogue scale (VAS) score was (5.6±1.9) in average (range from 3 to 9) at preoperation,and (2.0±1.5) at post-operation,which was significantly lower than that of preoperation,and the pain was relief obviously.There were 13 cases in grade C,11 cases in grade D,7 cases in grade E of American Spinal Injury Association (ASIA) grade neurological function before surgery,compared with the pre-operation,there were 5 cases in grade C,6 cases in grade D,20 cases in grade E of post-operation,which was significantly improved.MSTS (Musculoskeletal Tumor Society) 93 score was 6-29 points (20.0％-96.7％) at the follow-up 3 months after surgery,with the average of (19.8 ± 5.8) points,which excellent in 8 cases,good in 14 cases,general in 5 cases,poor in 4 cases.Two cases of dysporia for the reasons of resecting on one side of the S1,2 nerve roots involved by the sacral chordoma,after sacrificing the nerve root of complete tumor resection,the urine left dysfunctional,while the pain of other 29 patients were thoroughly relief after surgery.The ones were relieved with the disturbance of sensation of the perineum before the operation.2 cases were recovery of leakage of cerebrospinal by the drainage of lumbar cistern with normal temperature.One hypostatic pneumonia patient was cured by anti-inflammatory.One with the urinary infection got better by the effective bladder irrigation,which had diabetics mellitus with the bladder stoma before.1 case of skin necrosis due to vascular thrombosis before operation,recevied flap translocation half month after surgery,got recovery 3 months later.Only one underwent tumor resection for the recurrence at 15 months follow-up.Conclusion It is feasible and safe to perform en bloc resection of primary sacral chordoma.This is the most effective means of managing method of the marginal resection of the tumor.Preoperative 3-D printing modeling enables better anatomical understanding of the relationship between the tumor,and can avoid vascular and nerves tissue injury,which can also assist in planning the surgical procedure,and be worth recommendation.

Objective To evaluate the mechanical stability of alternative reconstruction methods after total en bloc spon?dylectomy in the lower lumbar spine. Methods Eight adult fresh cadaveric lumbosacral spines (L1-S1) were adopted. Total en bloc spondylecotmy of the L4 vertebra was performed after intact testing. Four designed reconstruction samples were tested for the range of motion (ROM) of the spine:1) expandable artificial vertebral body and short posterior instrumentation at L3-L5 (SP), 2) ex?pandable artificial vertebral body and short posterior instrumentation with additional anterolateral fixation at L 3-L5 (ASP), 3) ex?pandable artificial vertebral body and multilevel posterior instrumentation at L2-S1 (MP), 4) expandable artificial vertebral body and multilevel posterior instrumentation with additional anterolateral fixation at L2-S1 (AMP). Nondestructive biomechanical test?ing was performed on each construct under loading control. The ROM for each construct was obtained by applying pure moments in flexion, extension, lateral bending, and axial rotation. Results In flexion, extension and lateral bending, the ROM of all the re?constructed constructs significantly decreased compared to the intact. The ROM of specimens with anterolateral fixation was less when compared to the ones without additional fixation. In lateral bending, MP (L:1.87° ± 0.32° , R:1.97° ± 0.33° ), ASP (L:1.89° ± 0.37°, R:2.08°±0.36°) and AMP (L:1.32°±0.29°, R:1.61°±0.33°) provided significantly less ROM than the SP (L:3.14°±0.35°, R:3.44°±0.34°). In axial rotation, the ROM of ASP (L:4.21°±0.58°, R:4.02°±0.59°) and AMP (L:3.56°±0.55°, R:3.52°±0.48°) was significant decreased when compared to the intact state (L: 7.47° ± 1.00° , R:7.57° ± 0.84° ). MP (L:6.33° ± 0.71° , R:5.88° ± 0.62°), ASP and AMP showed significantly less ROM than the short posterior fixation (L:9.28°±1.01°, R:9.48°±0.98°). AMP sig?nificantly decreased the ROM compared to MP. Conclusion After total en bloc spondylectomy of lower lumbar, long segmental fixation provided more stability to the construct than the short one. Compared to posterior fixation, circumferential fixations showed a higher stability. In contrast, multilevel segmental instrumentation with circumferential fixation did not provided more stability than the short constructs.

Objective To investigate procedure and therapeutic effect of resection and reconstruction for axis tumors through the sub mandible approach. Methods Between December 2004 to June 2010,17 patients with axis neoplasm underwent tumor resection and antero-posterior reconstruction through the combined the sub mandible-inner sternocleidomastoid muscle (SMIS) approach and posterior approach. Tumor lesions involved C2 in 11 cases, C2-3 in 4, C2-4 in 2. Eight cases involved vertebral body, and 9 involved both vertebral body and element. Fourteen primary lesions including 4 giant cell tumors, 4 plasmocytomas, 2 chordomas, 2 eosinophilic granulomas, 1 hemangiopericytomas and 1 lymphoma, and 3 metastatic lesions were involved in this study. Three types of reconstruction in upper cervical spine including titanium mesh plus vertically placed titanium plate, titanium mesh plus obliquely placed titanium plate and trimmed titanium mesh alone, were adopted after anterior tumor resection, and then posterior tumor resection and reconstruction were performed. Results All patients experienced pain relief and neurological improvement after surgery. Except for one incidence of screw pull-out which was corrected by a revision surgery, solid fusion was achieved in all patients. A follow-up period of 6 months to 6 years was available for this study. One patient died of cerebral infarction 9 months postoperative. Two patients with chordoma relapsed 13 months and18 months postoperative, respectively, of whom one died of high plegia and respiratory failure, and the other was alive with disease. Two patients with metastasis died of multiple remote metastases 12 months and 18 months postoperative, respectively. Conclusion Through the SMIS apporach, a satisfactory exposure can be obtained for axis tumor resection and reconstruction. Anterior reconstruction of upper cervical spine after tumor resection can be achieved with internal fixation system of cervical spine, which can improve intraopera-tive safety. The combined anterior reconstruction and posterior occipito-cervcial fixation can provide immediate stability, and benefit maintaining stability of upper cervical spine.

Objective To investigate the effects of current major management strategies on early survival of patients with severe injury of cervical spinal cord. Methods A retrospective analysis was done on 532 patients with severe injury of cervical spinal cord (American Spinal Injury Association Grades A and B). The correlations of the early survival and major treatment measures, post-injury temporary immobilization of neck, operation, tracheotomy, systemic nutritional support, administration of glucocorticoid, were analyzed by Binary Logistic Regression. The problems related to the major treatment measures were also analyzed.Results 438 cases survived within 1 month. There was a positive correlation between the early survival and operation and nutritional support. There was a negative correlation between the early survival and tracheotomy.There was not any significant correlation between the early survival and the other 2 measures. The early sur-vival rate for patients of operation was 93.5%, for those without operation was 32. 7%, for those of goodnutrition was 97.8%, for those without good nutrition was 66. 7%, for those of tracheotomy was 58.1%, and for those without tracheotomy was 87.5%. Conclusions For patients with severe injury of cervical spinal cord, active operation and fine systemic nutritional support may increase early survival rate, undue tra-cheotomy may increase the risk of early death, and glucocorticoid may not have an effect on improvement of early survival rate.