Objective To evaluate the clinical valueof the revision of total hip replacement(THR), to analyse the reason of the rev isions, and to discuss the main difficulties and measures to manage it.Methods From June 1998 to January 2002, 15 cases (15 hips) were revised on totalhip replacement. The reasons for revision in the cases were as follows:failure of primary operative techenique, loosening and sinking of the components, displacement of the prosthesis, erosion of the acetabulum, as well as fracture of the femoral stem. The main difficulties of the revision were:poor health condition of the patients; the remove of the prosthesis of the primary THR,especially the broken femoral stem and the cements; the loss of localbone. The measures to remove the broken femoral stem were described.ResultsAll cases were followed up 2.4 years on average: 2 patients died from heart disease and cerebrovascular disease respectively, while the good results were achieved in the others.No infection, dislocation, loosening, and other complications occurred. The good effects were related with following factors:mild degree of illness; no severe bone defect; most of the first femoral head replacement.Conclusion The revision of THRis a more difficult operation, so that the special instrument and equipment andoperative experience are required.
Objective To discuss the therapeutic effect of distal fixed modular femoral prosthesis for the hip prosthesis revision. Methods Between August 2004 and May 2008, cementless modular femoral prosthesis was used for hip prosthesis revision in 21 cases. There were 9 males and 12 females, aged from 49 to 72 years (mean, 64.6 years). The timefrom revision to total hip arthroplasty was 2 to 18 years (mean, 11.7 years). The causes of revision included aseptic loosening in 19 cases (5 cases were periprosthetic femoral fracture), and deep infection in 2 cases. First revision was given in all patients. Preoperative Harris score was 41.8 ± 3.5; pain visual analogue score (VAS) was 7.62 ± 0.86. Results All patients achieved heal ing of incision by first intention, and no deep venous thrombosis and nerve injury occurred. Twenty-one cases were followed up 2 to 6 years with an average of 4.3 years. No prosthetic loosening or infection occurred. Bone ingrowth was observed around the implant during the follow-up period. At last follow-up, 2 cases had femoral stem subsidence without obvious hip pain and other symptoms, and no special treatment was given. Harris score was 82.7 ± 3.3 and VAS score was 0.19 ± 0.51 at last follow-up, showing significant differences when compared with those before operation (P lt; 0.05). Conclusion The short-term result of modular femoral prosthesis is satisfactory in hip prosthesis revision, and it can improve the hip function and rel ieve the pain greatly.
Objective To evaluate the medium-term results of uncemented acetabular revision with impacted deep frozen morsell ized allografts. Methods From April 1995 to December 2001, 58 cases (62 hips) were performed acetabularrevision by use of deep frozen morsel ized allograft firmly impacted into local ized defects as well as the entire acetabular cavity, followed by insertion of a uncemented cup with supplementary screw fixation. There were 32 males (34 hips) and 26 females (28 hips), with age of (49.6 ± 15.4) years old. Among 62 hips, 32 hips involved in left side and 30 hips involved in right side. The cause of revision was aseptic loosening of the cup in 56 hips, septic loosening of the cup in 3 hips, and polyethylene l iner dislodging with severe acetabular osteolysis in 3 hips. The average interval between the primary total hip arthroplasty and the revision was (10.1 ± 3.9) years. According to the American Academy of Orthopaedic Surgeons classification, 42 hips belonged to type II and 20 hi ps to type III acetabular defects. The cl inical and radiographic results were analyzed postoperatively. Results All wounds healed by first intention. No deep venous thrombosis and infection occurred postoperatively. All patients were followed up 6-13 years (average 8.1 years). The Harris score was improved from 61.1 ± 10.2 preoperatively to 92.0 ± 7.3 postoperatively, showing significant difference between preoperation and postoperation (P lt; 0.05). The results were excellent in 46 hips, good in 10 hips, fair in 4 hips, and poor in 2 hips, the excellent and good rate was 90.3%. The time for allograft incorporation was (12.5 ± 4.4) months after operation. The annual polyethylene l iner wear rate was (0.13 ± 0.09) mm. Linear and cavitary osteolysis was observed in 2 and 12 hips, respectively. Heterotopic ossification developed in 7 hi ps (11.3%); 3 hi ps were rated as grade I, 3 as grade II, and 1 as grade III according to Brooker classification. One cup underwent revision for asepticloosening and 2 were defined as radiographic failures. Kaplan-Meier survival rate of the cup was 94.2% ± 3.3% at 8 years after operation. Conclusion The combination of uncemented cup component with deep frozen morsel ized allografts seems to be a rel iable solution for restoring bone stock, relocating the hip center, and stabil izing the cup in acetabular revision, and provides favorable medium-term cl inical and radiographic results.
ObjectiveTo conclude the revision reason of unicompartmental knee arthroplasty (UKA) using computer-assisted technology so as to provide reference for reducing the revision incidence and improving the level of surgical technique and rehabilitation.
MethodThe relevant literature on analyzing revision reason of UKA using computer-assisted technology in recent years was extensively reviewed.
ResultsThe revision reasons by computer-assisted technology are fracture of the medial tibial plateau, progressive osteoarthritis of reserved compartment, dislocation of mobile bearing, prosthesis loosening, polyethylene wear, and unexplained persistent pain.
ConclusionsComputer-assisted technology can be used to analyze the revision reason of UKA and guide the best operating method and rehabilitation scheme by simulating the operative process and knee joint activities.
Objective To compare the maximum pull-out strength of the upper il iac screw and lower il iac screw with and without polymethylmethacrylate (PMMA) augmentation, and to provide the experimental evidences for the rational use of il iacscrews. Methods Ten intact human il ium from 5 donated cadavers with formal in embalmed were selected. The bone mineral density (BMD) of L1-4 of each cadaver was measured with a dual energy X-ray absorptiometry. The screws placed in the upper and lower il iac column were named as the upper and lower il iac screw, respectively. Using 70 mm length and 7.5 mm diameter screws with and without PMMA augmentation, 4 il iac screw technique models were sequentially establ ished and tested as follows: upper il iac screw (group A), upper il iac screw with PMMA augmentation (group B), lower il iac screw (group C), and lower il iac screw with PMMA augmentation (group D). Each il ium was mounted on a material testing machine with its position similar to standing. Under 2 000 cycl ic compressive loadings of 100-300 N to the screw, the maximum pull-out strength of il iac screw was measured. Results The BMD value of the 5 human cadavers was (0.88 ± 0.06) g/cm2. All the il iac screws were inserted into the screw tracts accurately as expected. No screw penetrations of acetabulum or cortex was not observed through visual inspection. There was no “halo” ring sign surrounding any screw after the 2 000 cycle loading. The maximum pull-out strengths of groupsA, B, C, and D were (964 ± 250), (1 462 ± 266), (1 537 ± 279), and (1 964 ± 422) N, respectively. Group D exhibited the highest maximum pull-out strength among the 4 groups (P lt; 0.05). No significant difference was detected between groups B and C (P gt; 0.05); however, groups B, C showed higher maximum pull-out strength than group A (P lt; 0.05). Conclusion The lower il iac screw offers significantly higher fixation strength than the upper il iac screw; PMMA augmentation could effectively increase the fixation strength of il iac screws and therefore could be appl ied in the salvage of il iac screw loosening.
Objective To evaluate the strength of polyethylene l inercement interface when cementing a new linerinto a fixed acetabular cup in revision. Methods Twenty-five pairs of metal acetabular cups with polyethylene l iners were randomly divided into 5 groups: 1 group with standard locking device as control group (group A), other l iners were cemented into acetabular cups as 4 experimental groups. According to different intersection angles of metal acetabular cups with polyethylene liners and the polyethylene l iners with or without metal ball, the 4 experimental groups were no ball 0° group (group B), 0° group (group C), 10° group (group D), and 20° group (group E), metal acetabular cups intersected with polyethylene liners without metal ball in group B, with metal ball in groups C, D, and E, respectively. The lever-out biomechanical test reproduced in vivo failure mechanism was then performed to evaluate the lever-out failure strength of l iner-cement-metalcup interface. Results The values of l iver-out failure force were (626.68 ± 206.12), (915.04 ± 197.49), (449.02 ± 119.78),(814.68 ± 53.89), and (1 033.05 ± 226.44) N in groups A, B, C, D, and E, respectively, showing significant differences forcomparison among groups (F=8.989，P=0.000). The values of l iver-out failure force in groups B and E were significantlyhigher than that in group A (P lt; 0.05), but no significant difference was found between groups C, D and group A (P gt; 0.05).Conclusion Cementation of polyethylene l iner into a malposition shell meeting within 20° can provide enough fixed strength.
Objective To explore the failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra, and to summary strategies of revision. Methods The cl inical data from 9 cases undergoing posterior approach orthopaedic operation failure of thoracolumbar hemivertebra between June 2003 and June 2008, were retrospectively analyzed. There were 5 males and 4 females with a median age of 12 years (range, 1 year and 10 months to 24 years). All malformations were identified as fully segmented hemivertebra from the original medical records and X-ray films, including 2 cases in thoracic vertebra, 5 cases in thoracolumbar vertebra, and 2 cases in lumbar vertebra. The preoperative scol iotic Cobb angle was (45.4 ± 17.4)°, and kyphotic Cobb angle was (29.8 ± 22.0)°. The reason of primary surgical failure were analyzed and spinal deformity was corrected again with posterior revision. Results All surgeries were finished successfully. The operation time was 3.0-6.5 hours (mean, 4.5 hours), and the perioperative bleeding was 400-2 500 mL (mean, 950 mL). All incisions healed by first intention; no infection or deep venous thrombosis occurred. Numbness occurred in unilateral lower extremity of 1 case postoperatively, and the symptom was rel ieved completely after treatment of detumescence and neural nutrition. All cases were followed up 12-30 months (mean, 18 months). No pseudoarthrosis and implant failure occurred. The X-ray films showed that the bone grafts completely fused within 8-14 months (mean, 11 months) after operation. The Cobb angles of scol iosis and kyphosis at 1 week after operation and the last follow-up were obviously improved when compared with preoperative ones, showing significant differences (P lt; 0.05). No obvious correction loss was observed either in coronal or sagittal plane. Conclusion The failure causes of posterior approach orthopaedic operation are hemivertebra processing, selection of fixation and fusion range, and selection of internal fixation. If the strategies of revision are made after the above-mentioned failure causes are considered, the cl inical results will be satisfactory.
【Abstract】 Objective To review the progress in the treatment of bone defect by porous tantalum implant. Methods Recent l iterature was extensively reviewed and summarized, concerning the treatment method of bonedefect by porous tantalum implant. Results By right of their unique properties, porous tantalum implants have achievedvery good results in the treatment of certain types of bone defects. Conclusion Porous tantalum implants have their ownadvantages and disadvantages. If the case is meet to its indications, this method can obtain a good effect. Porous tantalum implants provide a new way for the cl inical treatment of bone defects.
Objective To evaluate the surgical skill, cause of revision, compl ications, prosthetic survival and postoperative function in revision of custom-made tumor prosthesis replacement of knee joint. Methods The cl inical data of 33 patients who received prosthetic revision surgery between June 2002 and June 2007 were reviewed. There were 17 malesand 16 females with an average age of 33.1 years (range, 16-67 years). The pathological diagnosis included 17 osteosarcomas, 11 giant cell tumors, 2 mal ignant fibrous histocytomas, 1 chondrosarcoma, 1 synovial sarcoma, and 1 l iposarcoma. The involved locations were distal femur in 22 cases and proximal tibia in 11 cases. The average interval between first prosthetic replacement and revision surgery was 45.3 months (range, 6-180 months). The reason for revision included local recurrence in 2 cases, deep infection in 8 cases, aseptic loosening in 7 cases, peri prosthetic fracture in 1 case, prosthetic stem fracture in 6 cases, and prosthetic hinge failure in 9 cases. Six patients with deep infection received two-stage revision surgery, while the other 27 patients received one-stage revision. Cemented prostheses were used in all patients. Allograft prosthetic composite and revisions were used in 2 patients who had deficit of diaphysis for stem fixation. Results In 17 patients who received both primary prosthetic replacement and revision, the operative time was (149.8 ± 40.5) minutes and (189.9 ± 43.8) minutes, and the blood loss was (605.2 ± 308.0) mL and (834.1 ± 429.9) mL for primary prosthetic replacement and revision, respectively; all showing statistically significant differences (P lt; 0.05). The mean time of follow-up was 45.1 months (range, 12-76 months). Heal ing between allograft and host bone was obtained in 2 patients with allograft prosthetic composite and revision after 1.5 years and 2 years, respectively. After revision surgery, 3 patients died of lung metastasis after 12-24 months, and other 3 patients havinglung metastasis were al ive with disease. Nine (30%) compl ications occurred in 30 patients who were al ive at last follow-up. The compl ications included wound infection in 2 patients, deep infection in 5 patients, mechanical problems in 2 patients. Prosthetic failure occurred in 7 patients (23.3%). The 5-year survival rate of revised prosthesis was 68.6%. The Musculoskeletal Tumor Society (MSTS) score at 6 months after revision (73.6% ± 14.4%) was significantly improved (P lt; 0.01) when compared with before revision (57.1% ± 10.6%). Conclusion The main reasons for revision of custom-made tumor prosthesis of knee joint were mechanical problems and deep infection. Although revision surgery of knee is relatively compl icated and has some compl ications, a functional l imb could be maintained in most tumor patients.
fter total hip replacement ,massive bone defect occured freqently due to wearing and loosening of the prcathesis.The use of deep-freezing allograft to su pport a new implant was an attractive solution. Deep-freezing decreased the immune antigenicity of the transplanted allograft.From 1972 to 1990. the deep-freezing allografts were used in rcvision total hip replacement in 212 cases,in which 187 cases(198 hips) were followed-up for over 1 year.The general effective rate was 85%....
