Objective To investigate individual variations of the femoral isometric poiIit of anterrior cruciate ligament(ACL). Methods The femoral isometric points(i)were determined by measuring the knee joint lateral projections in 100 adults.The distances from the femoral isometric point i to the posterior border of intercondylar notch were measured and compared among 4 age groups(20 to 30 y,30 to 40 y,40 to 50 y and>50 y)by 2 × 2 factor analysis and Student-Newman-Keuls (SNK-q)Analysis to determine the effects of age and gender on the measurements. Results The average distance was(10.6±1.55)mm,ranging from 15.05 am to 7.50 mm.The 2×2 factor analysis showed the differences were signifcant between age groups(F=2.843,P=0.042)and between sexes(F=4.245,P=0.042).but the age and sex factors were not interacted (F=0.456,P=0.7 14). The SNK-q Analysis revealed the differences were significant between the 20 to 30 y group and the 40 to 50 y group as well as the>50 y group(P<0.05),but not significant between the 30 to 40 y group and the 20 to 30 y group(P>0.05).No signifieant difference was observed between any two of the 30 to 40 y group,40 to 50 y group and>50 y group(P>0.05). Conclusion Since the ACL femoral isometric points vary from person to person,it is valuable to check them twice radiologically before and during the operation.

Objective To explore the possibility and effectiveness of minimally invasive osteotomy and cable osteosynthesis for the treatment of adolescent eubitus varus. Methods Eleven cases of adolescent cubitus varns(2 cases complicated with internal rotation of 10°)were treated with minimally invasive supracondylar wedged osteotomy to preserve the integrity of the contralateral codex and periosteum.Two screws were inserted above and below the fracture line.They were fixed with cable after the greenstick fracture and internal rotation were adjusted.Plastic bandage was applied for 1 week postoperatively before rehabilitation. Results Bone fractures healed in the 11 cases in 36.3 days averagely,without infection or nerve palsy.Before operation,the mean angles of varus,flexion and extension were 35°±5°,125°±10°and 10°±5°respectively.After a mean follow-up of 33.5 months,the mean valgus angle of the elbow was improved to 8°±2°(t=16.632,P<0.05),flexion to 130°±8°and extension to 8°±3°(P>0.05).Internal rotation deformity was also ameliorated in the 2 cases. Conclusion It is practical and effective to treat adolescent eubitus varus with minimally invasive osteotomy and cable osteosynthesis,for it can lead to stable fixation,short healing time,and does not affect the flexion and extension of the elbow joint.

Objective To evaluate one-stage arthroscopic reconstruction of anterior crueiate ligament (ACL)and posterior cruciate ligament(PCL)using Achilles tendon-bone allografts. Methods From July 2000 to February 2005.we treated 15 patients(11 males and 4 females)whose ACL and PCL were ruptured at one knee but the eontralateral knee was intact.Their associated meniscus injuries were treated arthroscopically according to established procedures prior to ligament reconstruction.Thirty Achilles tendon-bone allografts were used to reconstruct torn ACL and PCL in 15 knees at one stage.Reconstruction of both ligaments was performed at subacute or chronic phase(>3 to 8 weeks)in 12 casses,and at acute phase in 3 cases(<3 weeks).All knees were graded pre-and postoperatively using the International Knee Documentation Committee(IKDC)and Lysholm scoring systems.At follow-up,functions were evaluated for all patients and compared with those of the contralateral healthy knee. Results All patients were followed up for a minimum of 3 years(mean,38 months).Preoperatively,the IKDC ratings showed all the injured knees were severely abnormal.At final postoperative f0Uow-up,9 knees received a normal rating,5 a nearly normal one and 1 an abnormal one.The differences in Lysholm score were statistically significant (t=15.660,P<0.05)between pre-and postoperative analyses.The most noticeable postoperative complication was a short localized fever coupled with arthroedema in 1 case. Conclusions Achilles tendon-bone allograft offers an alternative for simultaneous arthroseopic reconstruction of ACL and PCL.However,problems inherent in allograft tissues entail further investigation to ensure future application.

Objective To compare operative and non-operative treatments for intraarticular fractures of distal radius by meta-analysis. Methods The literature which had been published in English or Chinese from 1988 to 2008 on comparison between operative and non-operative treatments of intraartieular fractures of distal radius were searched for on line.Three Chinese papers and 2 English ones were eligibly included in this meta-analysis.The clinical data of the 5 papers were collected for comparing wrist function,reduction on X-rays,complications and patient's satisfaction. Results Operative treatment resulted in better reduction on X-rays,better wrist function and fewer complications but lower patient's satisfaetion than non-operative treatment. Conclusion The operative treatment should be recommended for intraarticular fractures of distal radius,but meanwhile the needs and expectations of the patient should be also addressed.

Objective To discuss factors influencing the heterotopic ossifications (HO) after treatment of bi-column acetabular fractures. Methods One hundred and ninety-three cases of bi-column acetabular fractures were followed up, including 147 males and 46 females with an average age of 34. 4 years. Thirty-one cases were associated with craniocerebral trauma. The interval between injury and surgery was less than 1 week in 15 cases, 1 to 2 weeks in 121 cases, 2 to 3 weeks in 34 cases, and over 3 weeks in 23 cases. Factors that might have influenced HO, including surgical method, associated injury, and interval between injury and surgery, were analyzed retrospectively. Results All the cases were followed up for an average of 44. 2 (14 to 84) months. The mean operation time was 238 (150 to 330) minutes, and the average blood loss was 1453 (450 to 4400) mL. The incidence rate of HO was 39. 9% (77 in 193 cases), including 39 cases of degree one, 23 cases of degree two, and 15 cases of degree three. Of the 77 cases associated with HO, 14 had craniocerebral trauma and 63 did not (χ~2 = 0. 019, P = 0. 891) . HO was found in 2 cases that had been operated on in less than 1 week, 38 cases in 1 to 2 weeks, 21 cases in 2 to 3 weeks, and 16 cases in over 3 weeks. The Spearman correlation analysis between HO degree and clinical result showed no correlation ( R = 0. 041, P =0. 722). Only 15 cases (7. 8% ) were associated with HO after the debridement of the necrotic gluteus minimus. Conclusions HO after surgery for bi-column acetabular fractures may not be correlated with craniocerebral trauma, but highly correlated with the interval between injury and surgery. Debridement of necrotic gluteus minimus and other muscles can reduce the incidence of HO.

Objective To discuss the factors which affect the postoperative functions of the ankle joint. Methods A retrospective study was done of 102 patients who had been diagnosed as malleolar fracture and operated on in our institute between January 2005 and January 2008. We recorded their age, gender, body mass index(BMI), fracture type (AO type), time from injury to operation and presence or ab-sence of cast immobilization. Their ankle functions were evaluated by X-ray and the Baird-Jackson evaluation system in regular follow-up. Relationship between the above-mentioned factors and the postoperative functions of the ankle joint was statistically analyzed, using univariate logistic regression and multiple stepwise logistic regression. Results A total of 102 patients were followed up for 24.7 (11 to 43) months. A negative correlation between the age, fracture type, reduction and postoperative function was found. The gender, body mass index (BMI), time from injury to operation and presence or absence of east immobilization, however, had no association with the postoperative function. The conservative treatment of the deltoid ligament injury complicated with the lateral malleolar fracture and/or improper treatment of the syndesmotic injury led to poor function. Conclusions The older a patient and the more serious a fracture, as well as the more unsat-isfactory the reduction, the poorer the postoperative ankle functions may be. To some extent, rational treat-ment of the deltoid ligament injury complicated with the lateral malleolar fracture and the syndesmotic injury may also determine the postoperative function of the ankle joint.

Objective To study the clinical outcome of percutaneous vertebroplasty (PVP) for the s disease who had been suffering severe back pain even after conservative therapy for months were treated with PVP. Their preoperative CT images indicated nonunion of factures and "vacuum signs". Dynamic X-ray films demonstrated formation of pseudoarthrosis in the involved vertebral bodies in some eases. Their back pain was evaluated with visual analogue scale (VAS). Their preoperative and postoperative VAS scores and radiological indexes were compared. Results The mean VAS scores were 7.0±1.2 preoperatively, but 3.1±1.5 at the follow-up (P < 0.05) . The height of anterior margin of involved vertebral body was (2.1±0.3) cm pre-operatively, but (2.3±0.2) cm at the follow-up (P < 0.05). The ratio of anterior margin height to posterior margin height of the involved vertebral body was 0. 67±0. 10, but 0.84±0.08 at the follow-up (P<0.05), The focal kyphosis angle was 27.3°± 6.4° preoperatively but 20.7°±5.0° at the follow-up (P < 0.05). No pulmonary embolisms or neurological injuries happened. Conclusion PVP is an effective method for anterior margin of the involved vertebral body partially, and decrease the focal kyphosis.

Objective To investigate the advantages of the external fixators used in the treatment of pelvic fracture. Methods From April 2002 to July 2008, 55 patients with unstable pelvic fracture were treated respectively with simple external fixators, external fixators plus traction and external fixators plus in-ternul fixation according to their different Tile classifications. Results Of this group, 51 cases were followed up for an average of 11 months, 2 cases died because of multi-injuries, and 2 cases were lost in the follow-up. All of the 51 patients obtained bony union. On average, it took 11 (6 to 14) weeks to achieve weight-bearing walking, and 12 (8 to 14) weeks to remove the external fixators for the patients. By Liu Li-ming's evaluation system, the good to excellent rate was up to 88.2%. Conclusions The pelvic fractures of Tile B1 and B2 can be treated with simple external fixators and those of Tile C with external fix-ators plus internal fixation or traction to achieve fracture reduction and stability of the pelvic ring. For the patients with multi-injuries, external fixators used in the emergency treatment can stabilize the pelvic ring, reduce blood loss and improve the success rate.

Objective To compare the clinical results of minimally invasive percutancous plate os-teosynthesis (MIPPO) and open reduction with internal fixation (ORIF) for treatment of distal tibial fractures. Methods From October 2006 to June 2007, 94 cases of closed distal tibial fracture with intact articular surface were treated by internal fixation with plates. Of them, 42 were treated with ORIF and 52 with MIPPO. We retrospectively analyzed their union time, malunion and complications. Results The average follow-up was 14.5 (8 to 24) months. In the ORIF group, 35 cases got union, 3 cases delayed union and 4 cases nonunion. The average time for union was 3.83 (3 to 8) months. There were no cases of malunion and 2 cases of superficial infection in this group. In the MIPPO group, 47 cases obtained union, 5 cases delayed union and none nonunion. The average time for union was 3.66(2 to 8) months. No significant differences were found between the 2 groups in total union time or in the union time for Type AI, Type A2 and Type B fractures respectively. The union time for Type A3 fracture was longer in the MIPPO group than in the ORIF group, but the union time for Type C fracture in the MIPPO group was shorter than in the ORIF group. In the MIPPO group, external rotation occurred in 2 cases and posterior angnlation displacement in 3, and 8 cases com-plained of discomfort around the ankle which was relieved after removal of the plate. Conclusions Gen-erally speaking, there is no significant difference between ORIF and MIPPO in union time for distal tibial fractures. ORIF may be superior to MIPPO in treatment of Type A3 fracture, but inferior to MIPPO in treatment of Type C fracture. A high rate of delayed union may be expected in patients who have been treated with MIPPO and have had anteroposterior angnlation.

Objective To explore the anti-sliding plating for Hoffa fractures by comparing the me-chanical properties of anti-sliding plates and cancellous bone screws. Methods Twenty cases of the same type of Hoffa fracture in the model femur were randomly divided into 4 even groups. Group A used 2 antegrade cancellous bone screws; Group B used 2 retrograde cancellous bone screws forwards; Group C used anti-sliding plate and locking screw fixation; Group D used anti-sliding plate and cancellous bone screw fixation. All the samples were subjected to the cycle fatigue and the maximum failure load tests. Results The fatigue test revealed no significant difference in the mean maximum displacements at the 10, 100, 1000, 10 000 cycles between the 4 groups. In the maximum failure load test, there were significant differences between Group A [(1224±72) N] and Groups C and D [(2183±227) N and (2124±235) N], as well as between Groups B [(1405±235) N] and Groups C and D; there was no significant difference between Group A and Group B, neither between Group C and Group D, Conclusions In the initial period after secure fixation for Hoffa fractures, anti-sliding plates and cancellous bone screws can all provide satisfactory mechanical stability and strength. But anti-sliding plating is recommended for cases of long healing expected, patients with great body mass index, and patients with poor compliance.