Objective To review the progress of the pedicle screw augmentation technique by bone cement. Methods Recent literature about the pedicle screw augmentation technique by bone cement was reviewed and analysed. The characters were summarized. Results Pedicle augmentation technique includes the augmentation of ordinary solid pedicle screw and hollow pedicle screw. Both types could increase the fixation strength and gain satisfactory clinical results. Bone cement leakage had a certain incidence rate, but most of cases were asymptom. Conclusion Bone cement augmentation of pedicle screw is an effective and safe internal fixation for poor bone condition.
【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 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 analyze the main reasons of acetabular component initial instabil ity after primary total hip arthroplasty (THA) and to disscuss the prevention and management. Methods The cl inical data were retrospectively analyzed from 19 patients undergoing revision for acetabular component initial instabil ity after primary THA between January 2003 and June 2010. There were 11 males and 8 females, aged from 55 to 79 years (mean, 67.2 years). The locations were lefthip in 9 cases and right hip in 10 cases. The cementless hip prosthesis was used in 12 cases and cement hip rosthesis in 7 cases. The revisions were performed at 3 weeks to 6 months after primary THA. The reasons of early failure were analyzed. Both the coverage rate of acetabulum-bone and the Harris hip score were compared between pre- and post-revision. Results The main reason of acetabular component initial instabil ity after primary THA may be unsuitable treatment of acetabulum, improper selection of acetabular component, and incorrect place angle of acetabular component. Sciatic nerve palsy occurred in 1 case and recovered at 7 weeks after revision. Sl ight fracture of the acetabulum in 1 case and healed at 3 months after revision. All incisions healed by first intention. No infection, vessel injury, displacement of acetabular component, or deep vein thrombosis occurred. The patients were followed up 11-73 months (mean, 28 months). At last follow-up, no acetabular component instabil ity was observed. The coverage rate of acetabulum-bone was increased from 67.9% ± 5.5% before revision to 87.7% ± 5.2% after revision, showing significant difference (t=11.592，P=0.003). The Harris hip score at last follow-up (84.4 ± 4.6) was significantly higher than that at pre-revision (56.5 ± 9.3) (t=11.380，P=0.005). Conclusion Detailed surgical plan, proper choice of component, correct place angle and elaborative planning, and proficient surgical skill are necessary to achieve the initial stability of acetabular component in THA．
Objective To evaluate the effectiveness of prosthetic revision using custom-made long stem prosthesis and allograft-prosthesis composite (APC) for aseptic loosening after bone tumor resection. Methods Between January 2002 and June 2008, 14 patients with aseptic loosening after bone tumor resection were treated. There were 8 males and 6 females,aged 21-70 years (mean, 43.9 years). The locations were distal femur (8 cases), proximal femur (2 cases), and proximal tibia (4 cases). Pain of the affected l imb occurred after 6-31 years of prosthesis replacement and worsened when bearing and walking; 6 patients had shortened l imb. The functional results were assessed quantitatively according to the functional rating system of the Musculoskeletal Tumor Society (MSTS). The MSTS score was 16.36 ± 1.50 before revision. The X-ray films showed obvious prosthetic loosening and subsidence. The average time of symptom was 4.5 years (range, 3-9 years). In 7 patients having severe bone loss (the decrease of the thickness of cortical bone was more than 50%) and the prosthetic subsidence was more than 2 cm, the revision operation with the APC was performed; in 7 patients having less bone loss (the decrease of the thickness of cortical bone was less than 50%), the custom-made long stem prosthesis was performed. Results All wound healed by first intention. Two patients had temporary peroneal nerve paralysis and recovered after 3 months. All the patients were followed up 3.6 years on average (range, 2 years and 2 months-7 years) after revision. After revision, pain was rel ieved and the range of joint was improved. The MSTS score was 23.43 ± 2.56 at 12 months after revision showing significant difference when compared with the preoperative score (t=8.910, P=0.024). The X-ray films showed that lucency space l ine around stem cement in 2 patients at 12 months, and no prosthesis loosening and infection occurred. Conclusion The prosthetic revision after l imb salvage surgery with prosthesis for bone tumors was acceptable. The good functional results can be achieved by the revision with the APC or the custom-made long stem prosthesis according to the bone loss.
Objective To analyze the effectiveness of transforaminal lumbar interbody fusion (TLIF) for failed back surgery syndrome (FBSS). Methods Between October 2003 and December 2007, 36 patients with FBSS were treated with TLIF. There were 19 males and 17 females with an average age of 52.6 years (range, 46-68 years) and an average disease duration of 1.6 years (range, 3 months-15 years). Of 36 patients, reoperation was performed in 25, 10 received 3 operations,and 1 had 5 operations. A total of 50 segments were involved in fusion, including L4, 5 in 12 cases, L5, S1 in 10 cases, L3, 4 and L4, 5 double segments in 8 cases, and L4, 5 and L5, S1 double segments in 6 cases. According to X-ray films, CT, and MRI examination, 12 patients were diagnosed as having lumbar instabil ity secondary to total laminectomy, 18 as having recurrence of lumbar disc protrusion, and 6 as having recurrence of lumbar spondylol isthesis. Results Dural rupture occurred in 1 case and was repaired by suturing without cerebrospinal fluid leakage was observed; 1 had deep incision infection of Staphylococcus; and 1 had transient single irritation sign because of hematoma formation and was cured after symptomatic treatment. The other incisions healed by first intention. No patients had permanent nerve injury or deterioration. Thirty-three cases were followed up 18-72 months (mean, 35.2 months). At 12 months, all the operated segments reached interbody fusion, and no breakage of screw or Cage dislocation occurred. Japanese Orthopaedic Association (JOA) scores showed significant difference (t=2.45, P=0.01) between before operation (14.2 ± 4.1) and 18 months after operation (23.9 ± 2.6). The rate of cl inical improvement was 90.9% (23 cases of excellent, 7 cases of good, 3 cases of acceptable). Conclusion The TLIF simpl ifies the manipulation of lumbar revision surgery and decreases the operation risk and the operative compl ications for the treatment of FBSS.
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.
Objective To investigate the reasons of failure of Gamma nail treatment for intertrochanteric fractures and define operative techniques of the revision surgery. Methods From January 1999 to January 2008, 20 cases of 432 patients treated with Gamma nails for intertrochanteric fractures were revised. There were 9 males and 11 females, aged 24-87 years (median 65 years). Among them, there were 4 cases of femoral shaft fracture, 2 cases of screw penetrating the femoral head,11 cases of screw cutting out the femoral head and neck, 2 cases of internal rotation malformation, and 1 case of nfection. The operative procedures of revision were as follows: 4 cases were treated with the long Gamma nail, 4 cases by adjusting the position of Gamma nail, 11 cases with artificial femoral head replacement, and 1 case by removing Gamma nail and debriding and reimplant the Gamma nail. Results The hospital ization days were 16-28 days (21.2 days on average); the bleeding volume during operation was 150-600 mL (380 mL on average). All wounds healed by first intention. Bed rest days were 7-15 days (12.5 days on average). All the patients were followed up for 1-8 years (5 years on average). The operations were successful, the femoral intertrochanteric fracture and femoral shaft fracture reached bony union. Compl ications such as loosening, breakage of hardware and coxa adduct were not observed. No loosening and dislocation of the prosthesis occurred. Among the patients with compl ications, 9 patients were treated with a Gamma nail again. Fracture heal ing was achieved within 2 to 5 months, with an average of 3 months. According to the WANG Fang et al. criterion for hip joint function, the results were excellent in 7 cases and good in 2 cases. In 11 patients who receieved artificial femoral head replacement, the hip joint function restored to normal. Harris score was 90-93. Conclusion Various causes such as osteoporosis, ti p-apex distance ( 25 mm), femoral shaft malformation, Gamma nail shortcomings may lead to compl ications after Gamma nail treatment for intertrochanteric fractures. Good results will be achieved by different revision techniques.
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.
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.