Spinal transpedicular drill guide: design and application.

Short-segment stability problems of the spine, such as fracture, pseudoarthrosis, tumor, degenerative disc, and spondylolisthesis should be resolved by short-segment stabilization methods. The "rod long, fuse short" technique using traditional Harrington or Luque rods still have unavoidable problems of facet arthritis at the segments temporarily instrumented but not grafted. Transpedicular fixation of the spine is currently being used in many systems. Biomechanical studies have shown that three-level transpedicular fixation is more rigid than five-level fixation of Harrington or Luque rods. Regardless of the system used, the primary concern is how the transpedicular screw can be inserted safely through the pedicle as deep into the vertebral body as possible. A spinal transpedicular drill guide has been designed for transpedicular screws, and a prototype has been completed. Cadaver studies have been carried out and transpedicular screw position has been confirmed by computed tomography scan. Early clinical experience has demonstrated its efficacy and safety.

Intraosseous screw fixation of anterior cervical graft construct after diskectomy.

This article describes a new technique of intraosseous screw fixation of the cervical spine, as well as a retrospective review of 27 patients who had anterior cervical interbody fusion after diskectomy and fixation with one intraosseous Herbert screw, with a minimum follow-up of 1 year. The study included 19 men and eight women. There were no neurologic complications at final follow-up evaluation. All patients had radiographic evidence of fusion. No screw breakage, back-out, or dislodgement occurred. Optimal intraoperative radiographic evaluation for accurate intraosseous screw placement is recommended. The use of intraosseous screw fixation is a useful addition to the armamentarium of the spine surgeon when fixation of anterior cervical graft after diskectomy is required. One hundred percent rate of union and prevention of complications related to the currently used anterior fixation systems are the major advantages of this method.

Drug use patterns and gender differences among heroin addicts hospitalized for detoxification.

BACKGROUND: There has been a surge of heroin abuse in Taiwan in recent years making it necessary to study and understand the characteristics, drug use patterns and behavior among heroin users. MATERIALS AND METHODS: Two hundred and eighty-three patients hospitalized for heroin detoxification received a diagnostic interview and a semi-structured interview which rendered the demographic information, medical history, and patterns of and reasons for heroin use. Differences between male and female drug users were also compared. RESULTS: More than half of the subjects (54.3%) were unemployed. The percentage of unemployment of female patients was significantly greater than that of male patients (75.9% vs. 48.0%, p<0.05). Women were significantly younger (p<0.001) and had a significantly earlier (p< 0.001) onset of heroin use than men. About one-third of the subjects (33.9%) were multiple drug users, with amphetamines as the most common (79.2%) concomitant drug of abuse. More men reported curiosity as the reason for first use, while more women reported peer influence as the reason for first use. CONCLUSION: This study showed that significant gender differences in employment status, age of first use, and reasons for drug use among heroin addicts. Further exploration of gender and cross-cultural differences could have important theoretical and treatment implications.

Spinal pedicle finder for transpedicular screw fixation--design and early clinical result.

Spinal transpedicular fixation has gained widespread popularity in the past 5 years. In biomechanical studies, the deeply-inserted transpedicular screws withstood the largest number of cycles in the cephalad-caudad and medial-lateral direction before failure. However, in clinical practice, the risk of screw placement which is too far medially or too far laterally do exist. The optimization of increasing screw depth to avoid complication is of significant clinical importance. A Spinal Pedicle Finder (S.P.F) has been designed for transpedicular screws and a prototype has been completed. It is composed of an I-shaped body with a pair of front rails and a pair of rear rails. The front rail comprises two positioning arms that fit against the laminal bony crest, and the rear rail comprises two guiding bases that provide the transpedicular pin inserted with a specific angle. Both positioning arms and both guiding bases can be adjusted synchronously, and the specific angle over the guiding bases can be pre-set preoperatively according to the angle of pedicle axis. To date, in 7 cases (5 fracture and 2 spondylolisthesis) transpedicular screw fixation has been applied by aid of the S.P.F. Two-level fixation was applied in a fracture group and three-level fixation was applied in a spondylolisthesis group. The position of the transpedicular screw has been checked by CT scan postoperatively. A total of 32 transpedicular screws were inserted and all were in the pedicle and vertebral body except in one instances. One transpedicular screw was malpositioned on one side, partially lateral to the pedicle. However, this malposition did not cause any neurologic problem, such as dural tear, nerve root injury or other. Clinical experience has demonstrated its efficacy and safety.

One Herbert double-threaded compression screw fixation of displaced type II odontoid fractures.

Surgical treatment of type II odontoid fractures (OFs) has usually entailed C1-2 arthrodesis rather than fracture fixation. An alternative treatment of direct screw fixation is used to treat the fractures for preservation of atlantoaxial rotation. Type II OFs that cannot be completely reduced by close means are generally believed to be a contraindication for anterior screw fixation. Seven patients (group I) with displaced type II OFs that could be completely reduced were treated with fracture fixation by one 4.5-mm double-threaded compression screw and five patients (group II) with displaced type II OFs that could only be partially reduced were treated with fracture fixation by one 3.0-mm double-threaded compression screw. All patients had a minimum of 1-year follow-up. No major complications occurred. No loss of reduction occurred in group I patients. Group II patients had an average loss of reduction of 0.8 mm anterior displacement and 5 degrees anterior angulation. The overall rate of fracture union was 100%, and fracture resolution averaged 4.1 months. Ten patients had a normal range of cervical rotation, and there was no difference in preservation of cervical rotation between the two groups. Our results suggest that close reduction and compressive osteosynthesis by one double-threaded compression screw is an optimal method of treatment for displaced type II OFs that can be completely reduced and for some cases that can only be partially reduced. A 100% rate of fracture union and preservation of cervical rotation are the major advantages of this method. However, significant complications have been reported by other investigators. (ABSTRACT TRUNCATED AT 250 WORDS)