ObjectiveTo summarize the progress on the distal interlocking screw of cephalomedullary nail for intertrochanteric fractures. MethodsRelated literature concerning the distal interlocking screw of cephalomedullary nail was reviewed and analyzed in terms of biomechanics, clinical application, operating difficulties, and complications. ResultsDistal interlocking screw can provide extra torsional stiffness in both short and long cephalomedullary nail. It is applied in most clinical cases. In long cephalomedullary nail, placing the distal interlocking screw increases the operative time for fixation and the amount of radiation exposure notably. In short cephalomedullary nail, placing the distal interlocking screw can cause adjacent vascular injury, stress concentration, and secondary fracture around the screw. ConclusionWhen the fracture is stable (type A1, type A2.1), it can be fixed solidly without the distal interlocking screw, but prefers to use a long nail. In unstable fracture, the distal interlocking screw should be used to prevent rotational displacement of the femur shaft and the failure of the nail.
OBJECTIVE: To investigate an alternative procedure for complete denervation of bladder in the supra-cone cord injury to restore the bladder function. METHODS: Sixteen dogs were included in this study after their spinal cords were transected above the cone. They were divided into 6 groups and performed the rhizotomy of L7 to S3 root in different combination respectively. The bladder and urethra pressure change by electrostimulation during operation and cystometrogram change after operation were tested. RESULTS: 1. Electrostimulation study: for bladder innervation, S2was the most important and S1 was secondary. While for urethra innervation, S1 was more important than S2. When the anterior and posterior roots of S1 and S2 were intact with rhizotomy of posterior roots of L7 and S3, stimulated the common or posterior root of S1 and S2, the change of pressure in bladder and urethra was the same. When the anterior roots of S1 and S2 were resected with rhizotomy of posterior roots of L7 and S3, the pressure in bladder and urethra was significant decreased compared to stimulating the corresponding posterior roots. 2. Cystometrogram (CMG) study: in the complete deafferented group, resecting the posterior roots of L7 to S3, the bladder became flaccid. While resecting the posterior root of S2 and anterior root of S1 or, resecting the posterior root of S1 and anterior root of S2, combining with rhizotomy of posterior roots of L7 and S3, the CMG curve was similar to the complete deafferented group. In the S1 and S2 intact group, the bladder became spastic. CONCLUSION: Combining rhizotomy of anterior and posterior sacral root in different level has the same effects on bladder as complete deafferentation.
ObjectiveTo design a new type of short femoral intertrochanteric nail (FITN) with anterior curvature (19.5 cm in length and 120 cm in radius) and observe the geometric match with medullary cavity of the femur. MethodsBetween November 2015 and June 2016, 25 geriatric patients with femoral intertrochanteric fractures were treated with the newly designed FITN. There were 7 males and 18 females with an average age of 82.3 years (range, 65-94 years). According to AO/OTA fracture classification, 3 cases were rated as A1.2, 2 cases as A1.3, 5 cases as A2.1, 8 cases as A2.2, and 7 cases as A2.3. The interval between injury and operation was 3.2 days (range, 2-7 days). Postoperatively, the nail entry point position (anterior, central, and posterior) on sagittal plane, the nail tip position (6-grade scale) and the nail tail level (3-grade scale) were measured using fluoroscopy and X-ray films to evaluate the geometric match of the nail with medullary cavity of the femur. ResultsOne patient with Parkinson disease died of asphyxia and pulmonary infection. The other 24 patients were followed up 1-8 months (mean, 4 months). Fracture union time was 6-10 weeks (mean, 8 weeks). The mean Parker-Palmer mobility score was 5.5 (range, 4-8). No patient had hip-thigh pain. The nail entry point was positioned anterior in 2 cases (8%), central in 18 cases (72%), and posterior in 5 cases (20%). The distal nail tip located at the central canal axis (grade 0) in 15 cases (60%), at anterior without contact with the anterior inner cortex (grade 1) in 8 cases (32%), at posterior (grade -1) in 1 case (4%), and at anterior with slight nail-tip impingement with the anterior cortex (grade 2) in 1 case (4%). The proximal nail tail level did not protrude out beyond the greater trochanter (grade 0) in 13 cases (52%), protruded out less than 5 mm (grade 1) in 9 cases (36%), and more than 5 mm (grade 2) in 3 cases (12%). ConclusionThe newly designed FITN has a good geometric match with the femur medullary canal in Chinese population, which may reduce the nail related complications.