Objective To introduce a new CT classification system we designed for Hoffa fractures and compare the interrater reliability between the CT and X-ray classification systems.Methods A total of 20 isolated Hoffa fractures from January 2008 to December 2011 were randomly selected for the present analysis of their imaging data (anteroposterior and lateral X-ray films of the knee joint and three-dimensional CT reconstruction of the femoral condyle).At the same time,a total of 20 independent observers (clinicians with junior,intermediate and senior professional qualifications) were selected for classification of the Hoffa fractures in the same manner respectively according to the Letenneur's X-ray system and our self-designed CT system.We used Kappa statistics to evaluate the interrater reliability among the clinicians between the 2 classification systems for Hoffa fractures.Results According to the CT classification of the 20 Hoffa fractures by the 20 clinicians,type Ⅰ,Ⅱ and Ⅲ fractures accounted for 66.0％,30.5％ and 3.5％ respectively.In type Ⅰ fractures,type Ⅰb involving zone b accounted for the most (50.0％),next by type Ⅰc(31.0％) and type Ⅰa (19.0％).In type Ⅱ comminuted fractures,fracture fragments were mostly seen in zone b.The overall incidence of fractures involving zone b by CT classification was 67％.According to the X-ray classification,type Ⅰ,Ⅱ,Ⅲ and Ⅳ fractures accounted for 31.4％,14.3％,28.0％ and 26.3％,respectively.The interrater reliability for CT classification agreement (Kappa =0.681) among clinicians was higher than that for X-ray agreement (Kappa =0.261).Conclusion For Hoffa fractures,communicated ones in particular,our CT classification system may be better than the X-ray classification system.

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.

Objective To evaluate the cross-screws fixation for displaced radial neck fractures.Methods A total of 29 patients with displaced radial neck fracture (Mason type Ⅱb) were treated by open reduction and cross-screws fixation at our department from October 2009 to August 2012.They were 18 males and 11 females,aged from 18 to 56 years (average,37.2 years).The fractures affected 16 left and 13 right sides.The time from injury to operation was from 3 to 72 hours,with an average of 33.9 hours.All fractures were displaced by more than 2 mm or angulated by more than 30°,and caused by simple falling.The elbow function was evaluated by the Broberg & Morrey scoring system at one year postoperation.Results All the 29 patients were followed up for an average of 16 months (range,from 12 to 29 months).All fractures healed within 3 months,ranging from 4 to 12 weeks (mean,10.6 weeks).By the Broberg & Morrey scores at one year postoperation,15 patients were rated as excellent,10 as good,3 as fair and one as poor,giving an excellent to good rate of 86.2％.No wound infection,neural injury,fracture displacement or fixation failure occurred.No implants were removed due to local uneasiness.Conclusion Cross-screws fixation can achieve satisfactory outcomes for radial neck fractures.

0.05). Conclusions Our findings reveal that ORIF will not result in different prognostic outcomes for talar body fractures and talar neck ones. The displaced(≥ 2 mm) fractures of both talar body and neck must be treated by open reduction and internal fixation depending on conditions of soft tissue. We should protect the residual blood supply, reduce the fracture anatomically and decrease the rate of posttraumatic arthritis, ischemia and necrosis of talus.

The article gives a brief account of the functional anatomy of the shoulder, and analyzes the movement of the shoulder and the function of each muscle involved in the movement. On the basis of the anatomy, the article also describes the anterior, lateral and posterior approaches to the shoulder, surgical procedures and points for attention related to the approaches.

Objective: To determine whether 3-dimentional CT scans is able to effectively improve the detection rate of AO B3 distal radius fractures in clinics.Methods: From Jan 2013 to Jan 2014, 30 patients with distal radius fractures were retrospectively enrolled in this study, all the patients directly visited the skeletal trauma emergency department in Beijing Jishuitan Hospital post injury and all of them accepted open reduction and internal fixation of distal radius fractures at last.All the radiographic data including X ray films and 3-dimentional CT scans of these patients were collected.Two independent observers were required to make primary AO classifications for each fracture by X rays at first, then to make final AO classifications by 3-dimentional CT scans.Finally, the detection rates of CT scans and plain films for AO B3 distal radius fractures and B3.3 distal radius fractures were compared, the agreements of the two methods for diagnosing AO B3 and B3.3 fractures were calculated by Cohen''s Kappa calculations.Results: All the 30 fractures were confirmed to be AO B3 distal radius fractures intraoperatively, and 10 of them were B3.3 fractures.The results were completely consistent with the results of 3-dimensional CT scans.However, only 80%(24/30) AO B3 distal radius fractures and 60%(6/10) B3.3 distal radius fractures could be diagnosed only by X rays.The detection rate of CT scans was proved to be significantly higher than X rays for diagnosing B3 distal radius fractures(100% vs.80%,P<0.05), the detection rate of CT scans was also proved to be significantly higher than that of plain films for detecting B3.3 distal radius fractures(100% vs.60%,P<0.05).The agreement of 3-dimentional CT scans and X ray was poor for detecting both the AO B3 distal radius fracture and B3.3 distal radius fracture (kappa=0).Most importantly, in the study process, two special kinds of B3 distal radius fracture were initially found and described by us.One was named as radial B3 fracture, and the other was named as ulna B3 fracture.Conclusion: 3-dimentional CT scans can effectively improve the detection rate of B3 and B 3.3 distal radius fractures, and also help find two special kinds of B3 fractures.

Objective To study the incidence and prognosis of avascular necrosis of femoral head after internal fixation of femoral neck fractures. Methods 137 cases of femoral neck fracture treated with internal fixation between January 1993 and December 1999 were evaluated retrospectively. The average age was 49.1 years ( range, 17-77 years ). According to Garden classification, 4 cases were of stageⅠ; 23 of Ⅱ; 71 of Ⅲ; 38 of Ⅳ. One case could not be classified. The mean duration of follow-up was 49.1 months with a range from 14 to 95 months. Results Until January 2001, avascular necrosis of the femoral head was found in 51 cases (37.2%), among them late collapse occurred in 33 cases (24.1%). Avascular changes of the femoral head were found within 5 years after injury in most of the cases. The common clinical findings in the patients with avascular necrosis were: limited motion, limp and pain. Even if segmental collapse developed, about 30% patients had no complaint of pain, but the average Harris score was obviously lower than that of the patients without collapse. Statistical results showed that the related factors influencing the prognosis of avascular necrosis and late collapse were: degree of displacement of the fracture and quality of reduction. The location and extent of necrotic area were markably related to the development of late collapse. Conclusion Follow-up after operation of femoral neck fracture is important, it should be taken at least for 5 years. Close and thoughtful examination is recommended, especially in the 2nd to 3rd year after injury.

Objective:To evaluate the clinical significance of pattern visual evoked potential (P-VEP) parameters on amblyopic patients with normal-vision atfer pleoptic therapy. Methods:We investigated 60 amblyopic children (8-12 years old) who gained normal-vision atfer pleoptic therapy. hTese patients were assigned to a unilateral amblyopia group (40 patients)and a bilateral amblyopia group (20 patients). Another 20 healthy children served as a control group. All patients underwent a full initial ophthalmologic and orthoptic evaluation. P-VEP test was performed in all. Amplitude and latencies were analyzed and compared among groups. The latencies of P100 waves in the amblyopic eyes were used to generate a multiple linear regression formula from sex, ifrst treatment age, baseline visual acuity, and cycloplegic refraction. Results:hTere was no signiifcant difference in the mean levels of best-corrected visual acuity among groups (P>0.05). A signiifcant prolongation of the latency and a decrease of amplitude of P100 waves were observed in the unilateral amblyopia group and the bilateral amblyopia group compared with the healthy control group (P<0.05). Amplitude and latencies of the fellow eyes in the unilateral amblyopia group were abnormal compared with the healthy control group (P<0.05). Multiple linear regression analysis revealed that the latencies of P100 waves were signiifcantly correlated with the ifrst treatment age, baseline visual acuity, and cycloplegic refraction (R2=0.52, P<0.05). Conclusion:Deifcits exist in the fellow eyes and in normal-vision eyes atfer pleoptic therapy. hTe delayed P100 latency is affected by the ifrst treatment age, baseline visual acuity, and cycloplegic refraction. Traditional amblyopic therapy may be not enough for vision function recovery.

Objective:To investigate the management of pelvic injury associated with complete anterior sacroiliac joint dislocation.Methods:In the study, 6 cases of pelvic injury associated with complete an-terior sacroiliac joint dislocation treated in Beijing Jishuitan Hospital from February 2008 to June 2014 were analyzed.We described the history and severity of injury, emergency treatment, and fracture radio-logy.In all the cases, the surgical treatment and postoperative functional exercise were performed.We followed up all the cases on an average of 1.6 years, assessed the postoperative recovery and summed up the treatment experience.Results:All the 6 patients with fractures recovered without infection and nerve symptoms after surgery.Their X-rays showed good reduction of sacroiliac joints.All the cases were followed up on an average of 1.6 years.Six months after surgery, the Majeed scores were perfect in 2 cases, good in 2, fair in 1, and poor in 1.The patients with poor scores suffered persistent pain, and decreased physical activity, and when walking long distances, they needed a walking stick.The 2 patients with low scores could not resume the original work.Conclusion:Pelvic injury associated with complete anterior sacroiliac joint dislocation is a special type of the pelvic injury since the managements during the emergency phase are difficult.The surgery should be done as early as possible, and the anterior approach is available for the reduction and fixation.

Objective To evaluate the incidence and imaging features of tibial plateau fracture combined with dislocation.Methods A total of 298 patients with intact imaging data treated for tibial plateau fracture from December 2012 to June 2014 were analyzed retrospcctively.Tilt angle of medial fragment fracture line,ratio of width of medial fragment to total plateau,surface area percentage,fragment height,and major displacement were measured on CT images using picture archiving and communication system (PACS).Results Eighteen patients (6.0％) had tibial plateau fractures combined with dislocation,with tilt angle of medial or posteromedial fragment fracture line of (62.1 ± 14.1)°.Eleven patients (61％) had split of the medial tibial plateau with surface area percentage of (46.3 ± 2.5) ％,fragment height of (43.9 ± 6.2) mm,and major displacement of (5.3 ± 2.1) mm.Seven patients (39％) had posteromedial fragment fracture with surface area percentage of (25.1 ± 5.7) ％,fragment height of (40.0 ± 10.1) mm,and major displacement of (4.8 ± 6.45) mm.Conclusions Fracture line of fracture-dislocation tibial plateau fracture is much often through the eminence or located at the lateral eminence with large medial or posteromedial fragments.Surgical approaches and directions of nailing should be considered properly according to the morphological characteristics.