ObjectiveTo introduce the method of prior-localization femoral tunnel by using a special positioning tool under the C-arm radiographic machine before surgery, and to study the effect on the knee function recovery after medial patellofemoral ligament (MPFL) reconstruction.MethodsBetween January 2014 and January 2016, 32 patients with recurrent unilateral knee patellar dislocation were treated by arthroscopic patellofemoral lateral retinaculum release and MPFL reconstruction. The femoral tunnel position during MPFL reconstruction was prior-localizated under C-arm radiographic machine before operation. There were 8 males and 24 females, aged from 15 to 37 years, with an average of 23.8 years. The time from injury to admission ranged from 1 to 24 months, with an average of 9.7 months. Isometric point distance was measured on CT three-dimensional reconstruction image after operation to evaluate whether the position of femoral tunnel was isometric, and knee joint function was evaluated by Lysholm score. Spearman correlation analysis was performed between isometric point distance and Lysholm score.ResultsAll the 32 patients were followed up 12-18 months (mean, 14.2 months). No symptoms of patellar subluxation or dislocation was found during follow-up. Patellar extrapolation test and patellar extrapolation fear test were negative. The isometric point distance was 1.5-5.9 mm (mean, 3.44 mm) at 3 days after operation. All femoral tunnels were located in equidistant tunnels. At last follow-up, the Lysholm score of the patients was 92.8±2.1, which was significantly improved when compared with preoperative score (54.4±2.8) (t=61.911, P=0.000). Isometric point distance was negatively correlated with Lysholm score (r=–0.454, P=0.009).ConclusionC-arm radiographic machine can locate the femoral tunnel position of MPFL easily and accurately before operation. The short-term and medium-term effectiveness are satisfactory, and the ionizing radiation injury caused by multiple fluoroscopy during operation is avoided.
Objective To develop a tractive spinal cord injury model in rats with a novel spinal distractor so as to supply the rel iable animal model for researching the pathological mechanism and rehabil itation treatment of tractive spinal cordinjury. Methods A novel spinal distractor was prepared based on previous study. Sixty adult Sprague Dawley rats (weighing 250-300 g) were randomly divided into 5 groups, 12 rats in each group. T12-L3 spinal structures in the rear area were exposed and then T13-L2 spinal cords were revealed via dual laminectomy and kept integrity. In group A, a novel spinal distractor was placed without distraction; in groups B, C, D, and E, the T12-L3 spines were tracted with a novel spinal distractor which put on transverses process of T12-L3 vertebrae. During the tractive period, the somatosensory evoked potential (SEP) was used to monitor spinal cord function. The SEP ampl itudes descended 50% and kept distracting for 5 minutes in group B and for 10 minutes in group C, and descended 70% and kept distracting for 5 minutes in group D and for 10 minutes in group E, respectively to establ ish the tractive spinal cord injury model of T11-L2. The improved combine behavioral score (ICBS) was recorded at 1 and 7 days after injury in 6 rats of each group. The T13-L2 spinal tissue specimens were harvested for the morphological observation by HE and Nissl’s staining and for neurons counting. Results In group A, the ICBS score was 0 at 1 and 7 days after operation, showing significant difference when compared with the scores of the other groups (P lt; 0.05). The ICBS scores of groups D and E were significantly higher than those of groups B and C (P lt; 0.05). Edema and hemorrhage were observed in spinal cord surface and normal morphological structures were destroyed at different extent in groups B, C, D, and E at 1 day. There were adherence and congestion between spinal cord surface and peripheral issue without luster at 7 days, and dura depression was observed at the injury section, especially in group E. Necrosis and dissolution occurred in some neurons, and Nissl body structure dissolved or disappeared in groups B, C, D, and E. The neuron counting gradually decreased in accordance with the aggravation of injury in groups B, C, D, and E, showing significant difference when compared with group A (P lt; 0.05). Significant differences in neuron counting were found among groups B, C, D, and E (P lt; 0.05). Conclusion The tractive spinal cord injury model in rats can be successfully establ ished with novel spinal distractor, and the model establ ished by SEP ampl itude descending 70% and keeping distracting for 10 minutes is more suitable for study in tractive spinal cord injury.
Objective To study the cl inical effect of expert tibial nail (ETN) in the treatment of the complex tibial fractures of type C. Methods From May to October 2008, 10 cases of complex tibial fractures of type C were treated with unreamed ETN and closed reduction. There were 7 males and 3 females aging from 23 to 50 years with an average age of 39 years. Fracture was caused by traffic accident in 6 cases, by crush in 2 cases, and by fall ing from height in 2 cases. According to Association for the Study of Internal Fixation (AO/ASIF) classification, there were 2 cases of 42-C1 fractures, 4 cases of42-C2 fractures, and 4 cases of 42-C3 fractures; including 4 cases of closed fractures and 6 cases of open fractures (2 cases of Gustilo type I and 4 cases of Gustilo type II). Results The mean duration of surgery and blood loss were 75 minutes (range, 60-110 minutes) and 55 mL (range, 20-100 mL), respectively. All the incision healed by first intension without compl ication of infection. All cases were followed up for 12-17 months (average 14 months). X-ray films showed that no breakage of nail, iatrogenic fracture, l imb shortening, and angulation deformity occurred. All fractures healed after 3-8 months (average 4.2 months). At last follow-up according to Johner-Wruhs standard for the functional recovery, the results were excellent in 8 cases and good in 2 cases. Conclusion ETN has an angular stable locking system for intramedullary nails, which can enhance axial and transverse stabil ity for the treatment of complex tibial fractures of type C. It will provide firm fixation and minimal invasion.