Objective To investigate the value of computer-aided design (CAD) in defining the resection boundary, reconstructing the pelvis and hip in patients with pelvis tumors. Methods Between November 2006 and April 2009, 5 cases of pelvis tumors were treated surgically using CAD technology. There were 3 males and 2 females with an average age of 36.4 years (range, 24-62 years). The cause was osteosarcoma, giant cell tumor of bone, and angiosarcoma in 1 case, respectively,and chondrosarcoma in 2 cases. According to the Enneking system for staging benign and mal ignant musculoskeletal tumors, regions I, I + II, III, IV, and I + IV is in 1 case, respectively. According to the principle of reverse engineering, 5 patients with pelvis tumors were checked with lamellar CT/MRI scanning, whose two-dimensional data were obtained in disease area. The three-dimensional reconstruction of pelvic anatomical model, precise resection boundary of tumor, individual surgical template, individual prosthesis, and surgical simulation were precisely made by computer with CAD software. Based on the proposal of CAD, the bone tumor was resected accurately, and allograft il ium with internal fixation instrument or allogeneic il ium with personal ized prosthetic replacement were used to reconstruct the bone defect after tumor was resected. Results The operation was successfully performed in 5 cases. The average operation time was 7.9 hours, and the average blood loss was 3 125 mL. Hemorrhage and cerebrospinal fluid leakage occurred in 1 case, respectively, and were cured after debridement. Five patients were followed up from 24 to 50 months (mean, 34.5 months). All patients began non-weight bearing walk with double crutches at 4-6 weeks after operation, and began walk at 3-6 months after operation. Local recurrence developed in 2 patients at 18 months after operation, and resection and radiotherapy were performed. According to International Society of Limb Salvage criteria for curative effectiveness of bone tumor l imb salvage, the results were excellent in 2 and good in 3. Conclusion The individual surgical template, individual prosthesis, and surgical simulation by CAD ensure the precision and rel iabil ity of pelvis tumors resection. The CAD technology promotes pelvis tumor resection and the reconstruction of pelvis to individual treatment stage, and good curative effectiveness can be obtained.
【Abstract】 Objective To di scus s the resect ion of tumors of pelvic ring and i t s recons truct ion ofdefects. Meth ods From January 1999 to December 2006, 48 patients with tumors in pelvic ring were treated and defects were reconstructed. There were 32 males and 16 females, aged 14-72 years(mean 45.1 years), including 12 cases of benign tumor and 36 cases of mal ignant tumor. Fourteen cases had lesions in region Ⅰ , 11 cases in region Ⅱ , 12 cases in region Ⅲ , 3 cases in region Ⅳ and 8 cases had two or more regions. The selection of surgical method: benign tumor in wing of il ium or in sacro-il iac articulation was curettaged , mal ignant tumors were resected radically or boardly . Benign or mal ignant tumor in pubis, ischium or pubic symphysis was resected radically , defects were reconstructed with plastic plate or not. For tumor affecting aceta bulum , resection of tumor and replacement of the peri- pelvic prothetic or artificial hip joint replacement were performed to reconstructthe function of hip joint. Results Twelve patients with benign tumors were followed up 12-72 months and could walk well, only 1 case relapsed locally. Thirty-six patients with mal ignant tumor were followed up 6 - 72 months, the survival time was 6-12 months in 2 cases (5.6%), 12-24 months in 2 cases(5.6%), 24-36 mongths in 6 cases (16.7%), 36-72 months in 14 cases (38.8%), and more than 72 months in 12 cases (33.3%); 28 patients (77.8%) could walk normally, 6 (16.7%) could walk with the help of walking stick , 2(5.5%) needed wheel chair to move. Compl ications occurred in 6 cases( including 2 venous thrombus,1 anoxic encephalopathy, 2 wound delayed heal ing, and 1 dislocation after total hip joint replacement); the patients’ condition took a turn for the better. Conclusion Operation is a favorable way for the treatment of pelvic tumor. Selecting convenient operation methods to resect tumors or reconstruction defects according the position of the tumor will do good favor to good results,increase the survival time and improve qual ity of l ife.
Objective To set up the experimemtal model with superior segmentalbone defect in acetabulum and implant the three-fin acetabular component, and examine the Von Mises stresses of pelvis bone with simulating single leg position in vitro using rosette strain gages method(RSGD). Methods Four kinds of three-fin components were made based on measurement of diameter, depth and roof thickness of acetabular specimens. These kinds of threefin acetabular components based on spreaded degrees of lateral fins(0,36,45 and 60°). The superiorsegmental bone defect of acetabulum in 4 cadaver pelvis specimens was made,then simulated the actual position to place implant into acetabular bone.A blank control group was set up.After being fit up the 7 sets of rosette strain gages,then specimen to test the pelvic Von Mises stresses simulating the static load of single leg on the mechanic machine.Progressive load was graded into 150, 300,450, 600, 750 and 900 N.We obtained the strains informations about loaded andun-loaded pelvis bone. Results Based on computed the strains informations,we were informed the Von Mises stresses about pelvis bone.The maximal Von Mises stresses of selected local position was 6.93 MPa and the minimal Von Mises stresses of selected local position was 1.08 MPa. Conclusion Providing the data about the mainpart of threefin acetabular component to optimize spreaded degrees of lateral fins.
Objective To investigate the pathogenesis, diagnosis, and treatment of the gluteal muscle contracture associated with an unequal leg length caused by the pelvis obliquity (GMC-PO).Methods The retrospective analysis was made on the clinical features and the follow-up results in 132 patients who had been admitted from January 1990 to December 2004 for GMC-PO. Among them, 73 weremale and 59 were female with a range in age from 5 to 26 years (average, 11 yr). All the patients were characterized by unsymmetrical contracture of the gluteal muscles, including unilateral and bilateral contracture. Of the patients, 89 had a clear limping and 78 had a clearly-unequal leg length. The X-ray examination revealed pelvis obliquity in 97 cases and an increased angle of the femur neck in 11 cases. The arc longitudinal incision was made into the posterolateral area nearby the greater trochanter and then lysis of thegluteal muscles was performed, combined with the skin traction of both legs andexercise training. Results Of the 132 patients withunequal gluteal muscle contracture before operation, 13 had a relative length difference of 0.5-1.5 cm between the 2 legs, 1 had a difference of 3.0 cm,and the remaining 118 patients had an equal leg length. Excellent and good resultswere achieved in 118 and 13 patients, respectively after the surgical release of the gluteal muscle contracture by the arc longitudinal incision into the posterolateral area nearby the greater trochanter,combined with postoperative skin traction and functional exercises. Only 1 patient had a poor result. The follow-up for 3 months to 14 years showed that thecure rate was as high as 99.2%.Conclusion The gluteal musclecontracture associated with an unequal leg length caused by the pelvis obliquity is a result of the unequal gluteal muscle contracture between the 2 hips and it can be cured with a comprehensive therapeutic method including the surgical release of the gluteal muscle contracture by the arc longitudinal incision into the posterolateralarea nearby the greater trochanter, and postoperative skin traction as well as the functional exercise.
ObjectiveTo investigate the methods and effectiveness of one-stage operation for pelvis and acetabular fractures combined with Morel-Lavallée injury by internal fixation associated with vacuum sealing drainage (VSD). MethodsBetween June 2008 and October 2012, 15 cases of pelvis and acetabular fractures combined with Morel-Lavallée injury were treated. There were 5 males and 10 females, aged from 18 to 67 years (mean, 36.8 years). Fractures were caused by traffic accident in 11 cases and crashing injury of heavy object in 4 cases. The time from injury to hospitalization was 3 hours to 9 days (mean, 5.4 days). Morel-Lavallée injury located in the above posterior superior iliac spine in 4 cases, greater trochanter in 7 cases, and anterior proximal thigh in 4 cases. In 10 cases complicated by pelvic fracture, there were 1 case of anteroposterior compression type, 3 cases of lateral compression type, 5 cases of vertical shear type, and 1 case of compound injury type; in 5 cases complicated by acetabular fracture, there were 1 case of transverse fracture, 1 case of posterior wall and posterior column fracture, 1 case of transverse acetabulum plus posterior wall fracture, and 2 cases of both columns fracture. Open reduction and internal fixation were used to treat pelvic and acetabular fractures, and VSD to treat Morel-Lavallée injury. When the drainage volume was less than 20 mL/d, interrupted wound suture or free skin grafting was performed. ResultsThe hospitalization time was 16-31 days (mean, 20.8 days). Thirteen cases were followed up 4-16 months (mean, 7.8 months). The healing time of Morel-Lavallée injury was 16-36 days after operation (mean, 21.3 days). All the wounds had primary healing, and no infection occurred. The X-ray films showed that all fractures healed, with a mean healing time of 13.6 weeks (range, 11-18 weeks). At 6.5 months after operation, according to Majeed function scoring system in 8 cases of pelvic fracture, the results were excellent in 5 cases, good in 2 cases, and fair in 1 case; according to Harris hip scoring in 4 cases of acetabular fracture, the results were excellent in 2 cases, good in 1 case, and fair in 1 case. ConclusionTo pelvis-acetabular fractures combined with Morel-Lavallée injury, internal fixation treatment for fracture and VSD for Morel-Lavallée injury not only can cure merge Morel-Lavallée injury effectively, but also can guarantee the operation timing and incision safty of the pelvis-acetabular fractures.
Objective Based on images of pelvic CT three-dimensional reconstruction, to establish three-dimensional coordinate system of pelvis and investigate the three-axis displacement classification of pelvic fracture and its reduction principles. Methods Between June 2015 and May 2016, 21 cases of normal pelvic CT data were included in the study, and the mean pelvic three-dimensional model was established. The pelvic three-dimensional axis was established by defining the origin as the midpoint of the anterior superior iliac spine. Based on this coordinate system, a three-axis displacement classification of pelvic fracture were built. To assess the clinical guidance value of the three-axis classification, 55 cases (29 males and 26 females, aged 11-66 years with an average of 35.6 years) of pelvic fractures were analyzed by this classification, and replaced and fixed according to the principles of the reverse reduction. Results According to the theory of three-axis, pelvic fractures were divided into x-axis positive displacement/negative displacement, positive rotation/negative rotation; y-axis positive displacement/negative displacement, positive rotation/negative rotation; z-axis positive displacement/negative displacement, positive rotation/negative rotation. The average incision of included patients with pelvic fractures was 7.1 cm. The average reduction time was 12.2 minutes and the average radiation time was 55.3 s. The average time of screw implantation was 27.2 minutes. Postoperative pelvic X-ray films or three-dimensional CT showed all pelvic fracture was reducted well and the screw or plate was implanted correctly. The average intraoperative blood loss was 96.5 mL, the average operation time was 2.1 hours, and the average hospitalization time was 18.7 days. All patients were followed up 6-53 months (mean, 16.7 months). At last follow-up, according to Matta standard by pelvic radiography evaluation, there were excellent in 39 cases, good in 13 cases, and fair in 3 cases, the excellent and good rate was 94.55%. Conclusion Based on three-dimensional coordinate system, three-axis displacement classification of pelvic fracture can illustrate the displacement mode of patient simply and accurately, and can also guide the intraoperative reduction precisely.
Objective To investigate the effectiveness of complete resection of bone tumor in pelvic zone Ⅱ and reconstruction with allogeneic pelvis, modular prosthesis, and three-dimensional (3D) printing prosthesis. Methods The clinical data of 13 patients with primary bone tumor in pelvic zone Ⅱ who underwent tumor resection and acetabular reconstruction between March 2011 and March 2022 were retrospectively analyzed. There were 4 males and 9 females with an average age of 39.0 years ranging from 16 to 59 years. There were 4 cases of giant cell tumor, 5 cases of chondrosarcoma, 2 cases of osteosarcoma, and 2 cases of Ewing sarcoma. The Enneking classification of pelvic tumors showed that 4 cases involved zone Ⅱ, 4 cases involved zone Ⅰ and zone Ⅱ, and 5 cases involved zone Ⅱ and zone Ⅲ. The disease duration ranged from 1 to 24 months, with an average of 9.5 months. The patients were followed up to observe the recurrence and metastasis of the tumor, and the imaging examination was performed to observe the status of implant in place, fracture, bone resorption, bone nonunion, and so on. The improvement of hip pain was evaluated by visual analogue scale (VAS) score before operation and at 1 week after operation, and the recovery of hip function was evaluated according to the Musculoskeletal Tumor Society (MSTS) scoring system after operation. Results The operation time was 4-7 hours, with an average of 4.6 hours; the intraoperative blood loss ranged from 800 to 1 600 mL, with an average of 1 200.0 mL. There was no reoperation or death after operation. All patients were followed up 9-60 months (mean, 33.5 months). No tumor metastasis was found in 4 patients receiving chemotherapy during follow-up. Postoperative wound infection occurred in 1 case, and prosthesis dislocation occurred in 1 case at 1 month after prosthesis replacement. One case of giant cell tumor recurred at 12 months after operation, and the puncture biopsy showed malignant transformation of giant cell tumor, and hemipelvic amputation was performed. The postoperative hip pain significantly relieved, and the VAS score was 6.1±0.9 at 1 week after operation, which was significantly different from the preoperative score (8.2±1.3) (t=9.699, P<0.001). At 12 months after operation, the MSTS score was 23.0±2.1, including 22.8±2.1 for patients with allogenic pelvis reconstruction and 23.3±2.3 for patients with prosthsis reconstruction. There was no significant difference in the MSTS score between the two reconstruction methods (t=0.450, P=0.516). At last follow-up, 5 patients could walk with cane assistance and 7 patients could walk without cane assistance. Conclusion The resection and reconstruction of primary bone tumor in pelvic zone Ⅱ can obtain satisfactory hip function, and the interface of allogeneic pelvis and 3D printing prosthesis have better bone ingrowth, which is more in line with the requirements of biomechanics and biological reconstruction. However, pelvis reconstruction is difficult, the patient’s condition should be evaluated comprehensively before operation, and the long-term effectiveness needs further follow-up.