After freatment of prosthesis replacement for 12 malignant tumer of the proximal humoral werereported. The operation were performed after the indications and methods of treatment had beendefined. All of the 12 cases were followed-up, in the average of 8 yeare. On functional evaluation , 8cases had satisfactory result , but per in 1 cases and 3 cases died from recurrence or metastasis withinfive years. The indieation of the procthetic replantation, the complications, and revision weredisecused.
ObjectiveTo evaluate the clinical value of multi-slice CT in the diagnosis of complications due to breast augmentation. MethodsWe collected the imaging data of 32 female patients who accepted multi-slice CT examination in the second People's Hospital of Chengdu after breast augmentation between February 2010 and February 2015. The position, shape, edge, internal density, leakage, rupture and hard nodules of the prosthesis were observed and analyzed carefully. ResultsIn the 32 patients with breast augmentation, 12 were normal with bilateral symmetry and without abnormal shape or density. Among the other 20 patients, 11 had capsular contracture, 5 had prosthesis leakage, rupture and hard nodules, 4 had breast infection, 1 had fibroadenoma, 1 had cystoma, and 5 had little calcified nodules in the breast tissue. ConclusionThe multi-slice CT scan can clearly and accurately show the position, shape and size of the breast prosthesis as well as the existence of leakage, rupture and hard nodules in the prosthesis. It plays a very important role in the diagnosis of the complications due to breast augmentation and can be effective guidance for clinical operation.
Objective To study the operative effect and complication of the prosthesis replacement of the proximal humerus with malignant tumor. Methods From October 1998 to August 2003, the prosthesis replacement was performed to treat the proximal femur with malignant tumor in 4 patients, including 2 patients with osteosarcoma (Enneking staging,ⅡA) and 2 patients with giancell tumor of the bone (ⅡA,ⅡB). By the International Society of Limb Salvage(ISOLS) criterion, the 2 cases of osteosarcoma were preoperatively scored as 4 and 5 points, and 2 cases of giant cell tumor of the bone were scored as 9 and 11 points. The patients’ psychological conditions as well as their limb pain, shape, locality, activity, and function werealso observed. Results The follow-up for 24-58 months (mean, 44 months) showed that there was no local recurrence or infection in all the patients except onepatient who had the loosening of the screws for the fixation 17 months after operation and had no treatment. After operation, all the patients had a better postoperative extention angle from 22° to 41°(mean, 25°), bending angle from 29° to 80°（mean, 35°）, abduction angle from 5° to 28°, and circumgyrate angle from 15° to 22° in their shoulder joints. However, the shoulder joint function was still unstable to some extent and the joints had a decreased strength. By the criterion formulated by the ISOLS, the postoperative score for assessing the 2 patientswith osteosarcoma was increased by 16 points when compared with the preoperative score; the score for the 2 patients with giant cell tumor of the bone was increased by 9.5 points.Conclusion The prosthesis replacement to treat the malignant tumor of the proximal humerus is the good method of choice and has a good therapeutic result; however, there are more complications and so the method should be cautiously employed in the clinical practice.
Objective To probe a satisfactory surgical management of the limbsalvage for osteogenic malignant tumors around the knees. Methods From January1989 to December 2001, 42 patients (19 males and 18 females, aged 12-46) with osteogenic malignant tumors around the knees underwent surgical management of the limb salvage, including prosthesis replacement, allogenous bone grafting, and bone cement with adriamycin filled. Based on the pathological examination, osteosarcoma was found in 11 patients, synoviosarcoma in 4 patients, malignant fibrous histiocytoma in 3 patients, and giant cell tumor of the bone in 19 patients. All the patients underwent neoadjuvant chemotherapy for 1-2 courses before operatioexcept the patients with giant cell tumor of the bone. The patients underwent prosthesis replacement, allogenous bone grafting, bone cement with adriamycin filled, and postoperative chemotherapy. By the Enneking evaluating system, the patients were assessed on their reconstructed limb functions after the reconstructive operation for the musculoskeleta malignant tumors. Of the patients, 37 were followed up after operation. Results According to the follow-up for 3-11 years (mean, 5.6 years) in the 37 patients, 2 patients had recurrence and metastasis of the tumor, and died 3 and 4 years after operation, respectively. One patient underwent amputation of the limb for local recurrence of the tumor. One patient had amputation of the limb for the preoperative radiotherapy and the infection and necrosis of the operative wound after the limb-salvage surgery. Two patients had amputation of the limb for the rejection of the allogenous bone graft and theformation of the fistula.Thirty-one patients had good wound healing andgood functions of the limb. The results were evaluated by the Enneking evaluating system as follows: excellent in 7 patients, good in 14, fair in 10, and poor in 6. Conclusion Making an early diagnosis, recognizing the operative indication, choosing the operative method, and performing the preoperative and postoperative chemotherapy and/or radiotherapy are the keys to achieving an ideal limb-salvage surgery for osteogenic malignant tumors around the knees.
Objective To study the effect of all-coated long stem prosthesis associated with allograft in revision total hip replacement (THR). Methods From January 1997 to January 2004, 20 patients with non-infectious loosened implant after primary THR were treated. There were 12 males and 8 females with a mean age of 65 years (58-77 years). The average period between primary THR and revision THR was 12 years (3-18 years). According to classification of Paprosky, there were10 cases of type II, 6 cases of type IIIA, 3 cases of type IIIB and 1 case of type IV. All-coated long stem prosthesis was used in all cases. Impacting bone grafting was done in 12 cases and impacting bone grafting associated with cortical strut grafting in 8 cases. The mean amount of morsel ized bone was 20 g (5-35 g), the length of cortical bone was 10-22 cm. Results All the incisions got heal ing by first intension. All patients were followed up for an average period of 36 months (16-48 months). Dislocation occurred at 5 days after operation and was cured with closed reduction and traction in 1 case. There was significant difference (P lt; 0.05) in the mean Harris score between preoperation (50.0 ± 2.3) and postoperation (90.0 ± 2.5). The X-ray checking showed that continuous radiolucent l ine of 3 mm occurred in 1 case, prosthesis subsidence of 5 mm and 7 mm in 2 cases and that no bone absorption was observed. Seven cases of cortical bone grafting union was achieved within 3 years except 1 case of cortical bone un-union. Conclusion It can obtained the initial stabil ization of prosthesis to use all-coated long stem prosthesis associated with allograft in revision THR to treat femur bone defect after THR. The short-term effects of the cl inical and X-ray checking are satisfactory, but future effect is to be observed.
In unicompartmental replacement surgery, there are a wide variety of commercially available unicompartmental prostheses, and the consistency of the contact surface between the common liner and the femoral prosthesis could impact the stress distribution in the knee after replacement in different ways. Medial tibial plateau fracture and liner dislocation are two common forms of failure after unicompartmental replacement. One of the reasons is the mismatch in the mounting position of the unicompartmental prosthesis in the knee joint, which may lead to failure. Therefore, this paper focuses on the influence of the shape of the contact surface between the liner and the femoral prosthesis and the mounting position of the unicompartmental prosthesis on the stress distribution in the knee joint after replacement. Firstly, a finite element model of the normal human knee joint was established, and the validity of the model was verified by both stress and displacement. Secondly, two different shapes of padded knee prosthesis models (type A and type B) were developed to simulate and analyze the stress distribution in the knee joint under single-leg stance with five internal or external rotation mounting positions of the two pads. The results showed that under a 1 kN axial load, the peak contact pressure of the liner, the peak ACL equivalent force, and the peak contact pressure of the lateral meniscus were smaller for type A than for type B. The liner displacement, peak contact pressure of the liner, peak tibial equivalent force, and peak ACL equivalent force were the smallest for type A at 3° of internal rotation in all five internal or external rotation mounting positions. For unicompartmental replacement, it is recommended that the choice of type A or type B liner for prosthetic internal rotation up to 6° should be combined with other factors of the patient for comprehensive analysis. In conclusion, the results of this paper may reduce the risk of liner dislocation and medial tibial plateau fracture after unicompartmental replacement, providing a biomechanical reference for unicompartmental prosthesis design.
Objective To review the progress and application of peripheral nervous microelectrode. Methods The recent articles on peripheral nervous microelectrode were extensively reviewed. The classification, the progress of the peripheral nervous microelectrode and its utilizable prospect in the control of electronic prosthesis were summarized. Results The microelectrodes had favorable functions of selective stimulation and recording. It provided an information transmitting interface between the electric prosthesis and peripheral nerves. Conclusion Peripheral nervous signal is a feasible signal source to control electronic prosthesis.
Abstract The fracture of the prosthetic stem after prosthetic replacement of femoral head is not rare. In this study, the photoeastic instrument was used to study the stress distribution on the prosthetic stem following its insertion and to analyse the factors influencing the fracture of the stem. Through the examination of 9 places in 8 cases, it was found that:(1) The removal of femoral calcar and the inframedullary filling of the bone cement directly influenced the stress distribution. (2) The valgus or varus condition of the prosthesis would lead to stress concentration on the stem. (3) Once lossening of the prosthesis occured it would change the preliminary installingstress distribution in the upper femur which would lead to fatigue fracture. Ths experimental data and clinical observation would provide scientific basis forthe prevention of fracture of prosthetic stem following prosthetic replacement of femoral head.
Objective To study the clinical feasibility of the prosthetic composites of the intercalary allograft and the segmental allograft in reconstruction of the skeletal defect after the limb tumor resection. Methods Between August 1999 and December 2003, 28 patients with skeletal defects after the limb tumor resection were treated with the intercalary allograft or the segmental allograft megaprosthesis composite for reconstruction of skeletal defects. The bone involvements were observed in 16 patients with osteosarcoma, 4 patients with parosteal osteosarcoma, 5 patients with Ewing sarcoma, and 3 patients with soft tissuesarcoma. Preoperative biopsy was performed on all the patients, and the pathological result was confirmed after surgery. According to the Enneking system, 5 patients were grouped in ⅠB and 23 patients in ⅡB. The patients with osteosarcomaor Ewing sarcoma received the standard chemotherapy before and after operation.Eighteen and ten patients received the segmental allograft prosthetic compositereplacement and the intercalary allograft with the interlocking intramedullary nail fixation, respectively. The functional outcome was evaluated by the MSTS score. Results According to the follow-up for 5-48 months (average, 24 months), local recurrence was observed in 1 patient who underwent amputation eventually. Of the 28 patients, 3 developed nonunion of the allografthost junction accompanied by severe resorption and 2 developed deep infection. No allograft fracture was seen in the patients. Most of the patients achieved a good functional result with an average MSTS score of 23.4. ConclusionThe prosthetic composite replacement of the intercalary allograft and the segamental allograft can be used n the skeletal defect reconstruction after the limb tumor resection. The stablecontact in the allografthost junction and the b intramedullary internal fixation can help to reduce the complication rate of the allograft.
Objective To introduce the occurrence mechanisms, prevention, and treatment measures of prosthetic aseptic loosening. Methods The recent original articles about prosthetic aseptic loosening were extensively reviewed and analyzed. Results Prosthetic aseptic loosening was a very complex process involving many mechanical and biological aspects. The main mechanical factors included prosthetic materials, shapes and sizes, implant fixation methods (including surfacetreatments), cl inical installation, interface micromotion, stress shielding, implant wear, interface integrity, and peri prosthetic high hydraulic pressure, etc.; the main biological factors included the types and sizes of wear particles, cell-activated responses, cytokine release, enzyme activation and allergic reactions to wear particles, etc.. Many measures should be adopted to effectively prevent and treat it, including improving materials and designs of prostheses, fixation techniques, surgical techniques, and drug treatments. Conclusion Prosthetic aseptic loosening is still a troublesome compl ication after joint replacements in orthopaedics, and more attention should be paid for its effective prevention and treatment.