Objective To investigate the impact of difference between the medial and lateral posterior condyle cartilage thickness on osteotomy in total knee arthroplasty (TKA) by measuring the thickness of the medial and lateral femur posterior condylar cartilage and the posterior condylar angle (PCA) in osteoarthritis (OA) patients. Methods Between May and December 2011, 53 OA patients (60 knees) scheduled for TKA met the inclusion criteria (OA group). There were 12 males (14 knees) and 41 females (46 knees), aged 57-82 years (mean, 71.9 years). The tibiofemoral angle was (183.2 ± 2.6) ° . Fifteen healthy volunteers (30 knees) were taken as controls (control group); there were 6 males and 9 females, aged 59-68 years (mean, 66.3 years). MRI scan data were imported into Mimics10.01 medical image control system to measure the thickness of femur posterior condylar cartilage and the PCA with and without femur posterior condylar cartilage. Results In the control group, the thickness of the medial and lateral femur posterior condylar cartilage was (1.85 ± 0.33) mm and (1.92 ± 0.27) mm respectively, the PCA with and without femur posterior condylar cartilage was (5.0 ± 0.9)° and (5.1 ± 0.8)° respectively, all showing no significant differences (P gt; 0.05). In OA group, the thickness of the medial and lateral femur posterior condylar medial cartilage was (0.45 ± 0.40) mm and (1.78 ± 0.51) mm respectively, the PCA with and without femur posterior condylar cartilage was (3.3 ± 1.7)° and (4.8 ± 1.8)° respectively, all showing significant differences (P lt; 0.05). In OA group, the difference between lateral and medial cartilage thickness was (1.33 ± 0.45) mm, and the difference between PCA with and without femur posterior condylar cartilage was (1.5 ± 1.3)°. There was a positive correlation between the difference of cartilage thickness and the difference of PCA (r=0.75, P=0.01). Conclusion There is significant difference between medial and lateral femur posterior condylar cartilage wear, which leads to difference of PCA. The difference will impact knee function and longevity of the prosthesis, so the difference should be considered during osteotomy.
Objective To investigate the operative method and to evaluate the cl inical outcome of proximal femoral nail antirotation (PFNA) in treating reverse obl ique fractures of intertrochanteric region of the femur. Methods From January 2007 to February 2008, 30 cases of reverse obl ique fractures of intertrochanteric region of the femur were treated by closed reduction and fixation with PFNA, including 14 males and 16 females and aging 40-88 years old with an average of 68.6years old. All patients had closed fractures. According to AO classification, there were 6 cases of 31-A3.1 type, 7 cases of 31-A3.2 type and 17 cases of 31-A3.3 types. The time from injury to operation was 2-14 days (with an average of 5.3 days). All 31-A3.1 and 31-A3.2 type farctures and 9 cases of AO 31-A3.3 type fractures were fixed with the standard PFNA, and 8 cases of 31-A3.3 type fractures with the PFNA-long. The cl inical and radiological examinations were done at 1, 2, 3, 6, 12, and 18 months after operation. The cl inical outcomes were evaluated according to the Sanders scoring. Results Iatrogenic fracture of femoral shaft occurred in 1 case; no additional procedures were appl ied as fracture kept favorable stabil ity. Superficial infection occurred in 1 case at 5 days after operation, wound healed after dressing change and intravenous antibiotic therapy. Other wounds healed by first intention. All cases were followed up for 12-19 months (mean 14.1 months). All fractures healed uneventfully after 12-30 weeks (mean 16.2 weeks). Five patients complained of hip pain, 2 patients had lateral leg pain, and the pain was el iminated after symptomatic treatment. One case compl icated by ipsilateral fracture of the tibial plateau had functional disturbance of knee, and one case compl icated by ipsilateral fracture of the acetabulum and pelvis had functional disturbance of hip, and the function was improved after functional exercise. No compl ications such as cut-out or breakage of the implants occurred. According to Sanders criteria, the cl inical results were excellent in 22 cases, good in 6 cases, and poor in 2 cases. The excellent and good rate was 93.3%. Conclusion PFNA is an effective treatment method for reverse obl ique fractures of intertrochanteric region of the femur, with a high rate of bone union, minor soft tissue damage, early functional exercise and acceptable compl icationrelated to implant.
To evaluate the cl inical results of less invasive stabil ization system (LISS) for femur supercondylar and intercondylar fractures. Methods From March 2004 to November 2005, 47 patients with 49 intercondylar and supercondylar fractures were treated. Of all the patients, there were 34 males and 13 females with an average of 39.7 years (range 19-56 years). The locations were left side in 21 cases and right side in 28 cases. Fracture was caused by traffic accident in 31 cases, fall ing in 8 cases, violence in 6 cases and others in 2 cases. Forty-nine fractures included 14 intercondylar fractures, 21supercondylar fractures and 14 intercondylar and supercondylar fractures; 32 closed fractures and 17 open fractures. According to the AO typing, there were 6 type 33-A1, 8 type 33-A2 , 10 type 33-A3, 7 type 33-C1, 3 type 33-C2 and 15 type 33-C3. The disease course was 30 minutes to 6 days. Articular surface reduction was first performed, then the LISS plate was inserted via two incisions and locking screws were used later. Results The average operation time was 126 minutes (range 48-248 minutes). The blood loss was 180 mL(range 60-1 200 mL). The average follow-up time was 18.6 months (range 12-23 months). There were 4 patients with AP angular deformity and 5 patients with lateral angular deformity (range 2-5°). External rotation deformity was presented in 2 patients. There were no plate breakage, screw loosen and fixation failure. Average bone union time was 5.6 months (range 3-8 months) without infection case. Six cases were treated with il iac bone transplantation for delayed union. Conclusion LISS is one kind of effective treatment to femoral intercondylar and supercondylar fractures.
Objective To analyse the factors of complications aftertreatment of intertrochanteric fractures with Gamma nail. Methods From January 1998 to May 2004, 50 patients were treated with Gamma nail, including 18 males and 32 females and ageing from 47 to 82 years. The locations were the left side in 16 cases andthe right in 34 cases. According to Evans classification, there were 4 cases oftype Ⅰ, 2 cases of type Ⅱ, 23 cases of type Ⅲ, 10 cases of type Ⅳ and 11 cases of type Ⅴ. Results Fifty patients were followed up 429 months. Accordingto the Harris criterion for evaluation, the results were excellent and good in 35 cases, showing sthenic weight loading walking and normal range of motion of the hip joint. The postoperative complications appeared in 15 cases: 5 cases of coxa vara or coxa valga, 3 cases of rotation deformity of lower limb, 2 cases oftension screwprotrusions and lower shorten, 1 case of failure of internal fixation, 1 case of femoral fracture, 2 cases of coxalgia and 1 case of pain in knee joint and stiff knee joint. Conclusion The reason of complications was various, mainly lies in insufficient comprehension and analysis of the types of fractures, unfamiliarity with the characteristics and usage of the instruments and neglected rehabi litation instruction, inappropriate functional training and too early weight loading after operation.
To investigate the effects of augmentation with bone cement on the biomechanics of the dynamic hip screw (DHS) fixation in the intertrochanteric fracture specimen that has a normal bone density.MethodsTwentyfour matched pairs of the embalmed male upper femora (48sides) were used to make the specimens of the intertrochanteric fracture of Type A2. All the specimens were fixed with DHS. The right femur specimen from each pair was fixed by augmentation with DHS (the augmentation group) and the left femur specimen was fixed with the conventional fixation (the control group). Thebiomechanical tests on the bending stiffness and the torsional stiffness were performed with the servohydraulic testing machine in the two groups.ResultsThe maximum load and the maximum torque were 3 852.160 2±143.603 1 N and 15.5±2.6 Nm in the augmentation group and 3 702.966 7±133.860 1 N and 14.7±3.4 Nm in the control group. There was no significant difference in the biomechanical effects between the two groups (P＞0.05). Conclusion The augmenting fixation with bone cement in the intertrochanteric fracture specimen with a normal bone density has no significant effect on the strength of the DHS augmentation or on the overall stability of the fractured bone.
Objective To discuss the method of constructingbiomechanical model of rabbit femur.Methods The sample of rabbit femur was prepared as follows:firstly，femur section images were obtained，then the image wasput into the computer and processed to get the boundary contour line; secondly, through programming the contour line coordinate for modeling was obtained, then the data were put into the model software to find the threedimensional entity model. Results Whole three-dimensional model of rabbit femur was constructed. It simulated actually dissection form of femur. Conclusion The establishment of the model lays a foundation for ascertaining optimal parameter of vibration improving bone minerydensity by finite element analysis.
Objective To compare heterotopic ossification between femoral head reconstruction and total hip arthroplasty(THA) in patients with ischemic necrosis of femoral head(INFH). Methods Between June 1994 and December 2004, the femoral heads were repaired in 1 005 patients with INFH,the total hip was replaced in 485 patients with INFH. The rate of heterotopic ossification was observed in 74 (Ficat Ⅲ to Ⅳ stages) of 1 005 patients and 80 of 485 patients given THA to compared the results of the two methods. Results These patients were followed up 2 to 10 years(6.5 years on average). The rates of heterotopic ossification were 5.4%(4/74) and 22.5%(18/80), respectively. There was statistically significant difference between two operative methods (Plt;0.01). Conclusion The rate of heterotopic ossification of femoral head reconstruction is lower than that of THA, so femoral head reconstruction is a better operative method for young patients and THA is suitable for old patients.
Objective To observe the effect of biological fixation of femoral stem prosthesis with multilayer macropores coating by combined use of autologousbone grafting. Methods The reconstructing femoral stem prostheses were designed personally, proximal 2/3 surfaces of which were reformed by thick multilayer stereo pore structure. Twentyfour adult mongrel canines underwent right femoralhead replacement and were divided randomly into two groups. The autogenous bonemud of femoral head and neck were not used in the control group. The histologicexamination, roentgenograms and biomechanical test were carried out in the 1st,3rd and 6th month after operation to observe the bone formation and fixation inthe exterior and interior sides of the prostheses. Results Onthe whole view,bone reconstruction occurred in experimental group in the 3rd and 6th month. Roentgenograms also proved to be superior to the control group. Histological examinationshowed that both the maximum bone inserting depth（μm） and average engorging ratio(%) of newly formed bone in experimental group surpassed those in the control group. The maximum shear strength of prosthesisbone interface in experimental group was significantly higher than that in the control group（Plt;0.01）. Conclusion Intensity of biological fixation can be strengthened remarkably by using femoral stem prothesis with multilayer macropores coating by combined use of autologous bone grafting.
Objective To evaluate the effect of composite (bFGF/PDPB) of basic fibroblast growth factor（bFGF） and partially deproteinized bone (PDPB) on the repair of femoral head defect. Methods Forty-eight femoral heads with defect derived from 24 New Zealand rabbits were divided into 3 groups at random, which were implanted with bFGF/PDPB(group A), PDPB(group B) and nothing(group C) respectively.The rabbits were sacrificed at 2,4,and8 weeks after operation, and then the femoral heads were obtained. The specimens injected with Chinese ink were created. Then X-ray examination, histopathological and morphological examination of blood vessel, and image analysis were made. Results The bone defects healed completely 8 weeks after operation in group A. The implants in the repaired tissue were not substituted completely in group B. The bone defects did not heal completely in group C. Two weeks after operation, affluent newly formed vessels were seen in repaired areas in groupA. No significant difference between group A and group B was observed 8 weeks after operation. In group C, newly formed vessels were scarce 2, 4, and 8 weeks after operation. There were 3 sides rated excellent, 2 good and 1 fair in group A; 1 excellent, 2 good, 2 fair and 1 poor in group B; and 1 fair and 5 poor in group C according to the X-ray evaluation 8 weeks after operation. Eight weeks after operation, the volume fraction of bone trabecula in repaired tissue was higher in group A than that in group B (Plt;0.05), and the fraction in group C was thelowest among the 3 groups (Plt;0.05). Conclusion The composite ofbFGF and PDPB can effectively promote the repair of femoral head defect of rabbit.
Objective To study the mechanism of compound of calcium phosphate(TCP) and platelet-rich plasma(PRP) in the treatment of femoral head necrosis.Methods The left femoral heads of 48 New Zealand white rabbits were frozen by liquid nitrogen as to make themodel of femoral head necrosis.Twenty-four rabbits were randomly chosen as theexperimental group and their femoral heads were filled with TCP/PRP. The other 24 rabbits were used as the control group and their femoral heads were filled only with TCP. They were sacrificed at 2, 4,8,12 weeks after operation. The specimens were examined with X-ray and histological study.Results At 2 weeks after operation,there was no significant difference in femoral headdensity between the two groups. Four weeks after operation, femoral head density decreased in both groups, while it decreased more in the control group. At 8,12 weeks after operation, the density of the femoral heads in both groups increased, and it was higher in the experimental group. Histology examination showed thatthere was no difference between the two groups 2 weeks after operation. The head became flat at 4 weeks. Control group had more defects. At 4,8,12 weeks, more repairs were observed in the experimental group than that in the control group. The amount and maturity of osteogenesis in experimental group were much more greaterthan those in control group．Bone histomorphometry showed that the volum of thetrabecular was larger in the experimental group (36.65%±7.22%,38.29%±4.28%，39.24%±3.42%) than that of control group(P＜0.05). Conclusion TCP/PRP does not only provide osteoblasts scaffold, butalso promotes bone formation and the head repair. TCP/PRP is a good biomaterialfor the treatment of femur head necrosis.