下颌三焦点牵张成骨过程中新骨组织骨形成蛋白的时空表达与影像学研究

目的 观察下颌三焦点牵张成骨过程中新骨组织骨形成蛋白的分布表达及影像学特征. 方法 选取4只成年恒河猴,通过下颌前分骨截除术形成颏部正中联合骨缺损.在两侧下颌体部各制备一个输送盘,用自行研制的多平面牵张装簧使双侧输送盘向前内方向缓慢移动并在颏部正中对接以修复颏部骨缺损.在牵张结束的第2、4、8与16周分别行X线或CT检查后处死,标本以抗骨形成蛋白(BMP)单抗免疫组化方法染色观察. 结果 免疫组化结果显示,牵张结束的第2周BMP广泛表达于牵开问隙的成骨细胞内,第4周成骨活跃,第8～16周BMP表达渐趋减弱.X线及CT影像显示新骨组织的钙化成熟是沿牵张方向逐渐发展,二者具有时相相关性. 结论 BMP在牵张成骨的早期起重要作用.X线及CT亦证明,在牵张弧形轨迹上,新骨组织从无到有,最终实现骨连续性及结构的恢复.     

Experienced surgeons can do more than one thing at a time: effect of distraction on performance of a simple laparoscopic and cognitive task by experienced and novice surgeons

Background While operating, surgeons are required to make cognitive decisions and often are interrupted to attend to questions from other members of the health care team. Technical automatization may be achieved by experienced surgeons such that these distractions have little effect on performance of either the surgical or the cognitive task. This study assessed the effect of adding a distracting cognitive task on performance of a basic laparoscopic skill by novice and experienced surgeons. Methods In this study, 31 novice (medical students in postgraduate years [PGYs] 1–2) and 9 experienced (fellows/attendants and PGYs 4–5) laparoscopic surgeons practiced the Fundamentals of Laparoscopic Surgery (FLS) laparoscopic peg transfer task until their scores stabilized. The mean normalized score after five repetitions then was recorded. The subjects also were tested on the number of mathematical addition questions they could answer in 1 min. This was repeated five times, with the mean number of questions attempted and the accuracy (% correct) recorded. The laparoscopic and addition tasks then were performed concurrently five times. Data, presented as mean ± standard deviation, were analyzed using Student’s t-test. A p value less than 0.05 was considered statistically significant. Results After practice to stable peg transfer performance, the baseline peg transfer score was higher in the experienced group (98 ± 6 vs 87 ± 12; p < 0.01). There were no baseline differences between the groups in the number of math questions attempted in 1 min (10 ± 2 vs 9 ± 2; p = 0.55) or the number of correct answers (9 ± 3 vs 8 ± 3; p = 0.36). The comparison of baseline performance and dual-task performance showed that the experienced surgeons had no decline in peg transfer score (98 ± 6 vs 97 ± 6; p = 0.48), number of questions attempted in 1 min (10 ± 2 vs 9 ± 3; p = 0.32), or number of correct answers (9 ± 3 vs 8 ± 3; p = 0.46). In contrast, dual-tasking among the novices was associated with a decrease in the number of questions attempted (9 ± 2 vs 8 ± 2; p < 0.01) and the number of correct answers (8 ± 3 vs 7 ± 2; p = 0.02), and with no change in the peg transfer score (87 ± 12 vs 88 ± 8; p = 0.38) compared with baseline. Conclusions Distraction significantly decreased a novice’s ability to process cognitively based math problems, whereas there was no effect on experienced subjects. This occurred despite the fact that the novice group had practiced to high-level peg transfer scores at baseline. This suggests that the experienced surgeons had achieved automatization of the peg transfer basic surgical skill to a level that cognitive distraction did not affect performance of either task. The experienced surgeons were able to attend equally to both tasks, whereas the novices attended to the surgical task at the expense of some aspects of cognitive task performance. Presented at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), Las Vegas, Nevada, USA, April 2007     

Post-Laminectomy Kyphosis in Patients with Cervical Ossification of the Posterior Longitudinal Ligament : Does It Cause Neurological Deterioration?

Objective

Total laminectomy (TL) is an effective surgical technique for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) along multiple levels. However, kyphosis and probable neurological deterioration have been frequently reported after laminectomy. We analyzed the changes in the cervical curvature after TL and subsequent changes in neurological status.

Methods

We retrospectively reviewed the records of 14 patients who underwent TL for the treatment of cervical OPLL between Jan. 1998 and Dec. 2003. TL was selected according to the previously determined criteria. The curvature of the cervical spine was visualized on a lateral cervical spine X-ray and measured using Ishihara''s Curvature Index (CI) before the operation and at the last follow-up examination. Perioperative neurological status was estimated using the modified Japanese Orthopedic Association score and the Improvement Rate (IR) at the same time as the images were evaluated.

Results

The mean age of the patients was 57 years, the male/female ratio was 10:4, and the mean follow-up period was 41 months. The mean number of OPLL was 4.9, and the mean number of operated levels was also 4.9. The CI decreased after TL (p=0.002), which was indicative of a kyphotic change. However, this kyphotic change showed no correlation with the length of the follow-up period, number of operated levels and preoperative CI. Neurological examination at the last follow-up showed an improved neurological status in all patients (p=0.001). There was no neurological deterioration in any case during the follow-up period. Moreover, there was no correlation between IR and the degree of kyphotic change. Postoperative complications, such as C5 radiculopathy and epidural bleeding, resolved spontaneously without neurological sequelae.

Conclusion

Kyphotic change was observed in all but one patient who underwent TL for the treatment of cervical OPLL. However, we did not find any contributing factors to kyphosis or evidence of postoperative neurological deterioration.     

Release of the transverse carpal ligament alone is associated with elevated pressure beneath the distal volar forearm fascia in a cadaver model of carpal tunnel syndrome

PURPOSE: The purpose of this study is to determine whether release of the distal volar forearm fascia (DVFF) is necessary at the time of median nerve decompression for carpal tunnel syndrome. METHODS: Five fresh-frozen cadaver specimens were mounted vertically with the hand dependent and a 2.27-kg weight suspended from the fingers. A pressure sensor wire was used to measure pressures starting just distal to the transverse carpal ligament (TCL). The wire was withdrawn proximally in 5-mm increments and into the forearm until pressure was below 10 mm Hg. An incision in the forearm was extended distally until the pressure sensor was found. The distance from this point to the distal volar wrist crease was measured. The TCL was released, keeping the DVFF intact, and the experiment was repeated. Paired t-tests determined whether there were statistically significant differences between measurements before and after TCL release. RESULTS: Average peak pressure under the intact TCL was 57.8 +/- 10.1 mm Hg. Average peak pressure under the DVFF with the TCL intact was 61.2 +/- 43.6 mm Hg. Following release of the TCL, average peak pressure beneath the TCL significantly decreased to 14.0 +/- 9.0 mm Hg, whereas average peak pressure at the intact DVFF increased to 64.8 +/- 48.7 mm Hg. Average locations where DVFF pressure became less than 10 mm Hg with an intact TCL and with released TCL were 4.30 +/- 1.8 cm and 4.00 +/- 1.8 cm proximal to the distal volar wrist crease, respectively. There was no significant difference between DVFF pressures before or after TCL release. CONCLUSIONS: In a cadaver model of carpal tunnel syndrome, release of the TCL alone is associated with persistent pressures >30 mm Hg in the region of the DVFF. Release of the TCL did not significantly change the location of the pressure drop-off under the DVFF.     

Effects of botulinum toxin A on functional outcome during distraction osteogenesis.

Distraction osteogenesis is useful for correcting limb length inequality, deformities, or short stature. Despite success with bone formation, soft tissue maladaptations including muscle and joint contracture may lead to undesirable results. Botulinum toxin A has been useful in treating spasticity in cerebral palsy, and has been used clinically in select cases to allay contracture in distraction osteogenesis. This study examines the toxin's efficacy in preventing distraction-induced loss of muscle strength and range of motion. The left tibias of 15 New Zealand White rabbits were distracted 1.5 mm/day until approximately a 20% gain was achieved. Each treatment group was divided into animals injected with saline or botulinum toxin in either the gastrocnemius or tibialis anterior muscles. A control group of two additional animals underwent no surgical procedure. Strength and range of motion were assessed prior to, and following, the experiment. At the study's end, animals were euthanized and muscles were harvested, when lengths and weights were recorded. All muscles injected with botulinum toxin showed decreased wet weight and persistent weakness upon completion of the study. Range of motion decreased in all distracted animals. When the gastrocnemius was injected, its strength was reduced but the tibialis anterior strength was preserved, and the limb achieved 22% greater dorsiflexion than saline controls (p = 0.016). When the tibialis anterior received the toxin, plantarflexion was increased by 23% (p = 0.049). Botulinum toxin injection prior to limb distraction increases the "post-lengthened" excursion of the injected muscle and this increased length may have a protective effect on its antagonist. In toxin-injected gastrocnemius muscles, the level of equinus contracture is reduced due to length gains in the Achilles tendon while the anterior tibialis maintains its ability to generate torque. Injection of botulinum toxin in the gastrocnemius may minimize equinus contracture and protect the anterior tibialis from damage during human tibial lengthening. Longer follow-up studies are needed to ensure that toxin-induced muscle weakness resolves with time.     

Forearm gangrene following distraction injury at elbow in a neonate

Gangrene of limbs in newborn is extremely rare. A number of aetiological factors may account for such type of situation. We describe herewith a case of gangrene of forearm in newborn following distraction injury to the physis of elbow and vessels of forearm by excessive pull on upper limb during difficult delivery.     

The significance of ocular bruits in ischaemic cerebro-vascular disease

The significance of ocular bruits has been studied in a series of 18 patients presenting with symptoms of atherothrombotic ischaemic cerebro-vascular disease and studied angiographically.

Twenty-five ocular bruits were heard. They were nearly always associated with carotid bruits in the neck but were not simply the transmission of these bruits up the carotid; they were seldom related to a carotid siphon stenosis at least as a single cause. Most of them were 'augmentation bruits', pointing in over half the cases to a tight stenosis or an occlusion of the origin of the contralateral internal carotid artery and in 75% to widespread atheroma of both the carotid and vertebrobasilar systems.

The presence of an ocular bruit in such patients should thus be considered as a warning of a complex and sometimes critical haemodynamic situation and should therefore lead to the greatest caution in contemplating both angiography and surgery.     

Treatment of severe late-onset Perthes’ disease with soft tissue release and articulated hip distraction: revisited at skeletal maturity

Purpose  Late-onset Perthes’ disease is diagnosed after 9 years of age. Conservative treatment and conventional surgical techniques have limited ability to reduce the pressure in the joint or change the shape of the femoral head. We used a combination of soft tissue release and joint distraction with a hinged mono-lateral external fixator for these patients. Ten of our patients reached skeletal maturity and were evaluated. Methods  Clinical assessment included: Harris hip score, hip range-of-motion (ROM), limb length discrepancy, and the Oxford hip questionnaire for pain and function. Radiographic assessment included: Sharp transverse acetabular inclination, the uncoverage percentage, the epiphyseal index before surgery (modified Eyre–Brook), at frame removal, and, at last follow-up, the epiphyseal quotient (of Sjovall) and the Stulberg classification. Results  Our study included eight boys and two girls (mean age at surgery 12.3 years, range 9.4–15.1, mean age at last follow-up 18.1 years, range 15.2–22.8). The mean follow-up was 5.7 years (range 4.3–7.8). The mean Harris hip score was 86.3/100 (range 48.5–96); one patient had <85 points. The hip ROM was slightly limited in most patients, and seven patients had limb shortening between 1–4 cm. The mean Oxford hip questionnaire score was 17.4/60 (range 12–31). The mean Sharp transverse acetabular inclination of the affected side was 42° (range 36–54) compared to 39° for the unaffected side (P = 0.045). The mean uncoverage percentage was 37% (range 27–47) compared to 20% for the unaffected side (P = 0.017). The mean epiphyseal index was 0.71 (range 0.31–0.92) before surgery, 0.79 (range 0.50–0.93) at frame removal (P = 0.012), and 0.72 (range 0.51–0.89) at last follow-up (P = 0.646). The epiphyseal quotient for the eight unilateral cases was 0.72 (range 0.49–0.91), and the Stulberg classification was type III for three cases and type IV for seven. Conclusion  Patient satisfaction for function and pain following the combined procedure was good. Radiographic parameters did not change significantly. This should be regarded as a salvage procedure.     

新型Ilizarov膝关节牵伸器的研制和临床应用

目的 :探讨用Ilizarov微创技术矫正各种类型膝关节屈曲畸形。方法 :在Ilizarov牵伸器基础上 ,研制了新型膝关节牵伸器 ;包括股骨、胫骨骨外固定器 ,并在膝关节两侧由关节铰链连接。术中安装时确定膝关节伸屈的旋转中心 ,用于伸缩的带弹簧牵伸杆安装在膝后的上下两个钢环上 ,手术中将牵伸器用 2mm克氏针交叉穿股骨和胫骨于膝关节中央 ,术后逐渐旋转牵伸杆 ,膝关节软骨面在避免挤压的情况下慢慢伸直。结果 :2 7例 3 0个膝关节 ,术后平均牵伸时间 5 8d ( 18d～ 10个月 ) ,全部病例膝关节伸直皆达到矫形需要的要求 ,未发生影响治疗效果的并发症。结论 :新型Ilizarov膝关节牵伸器的研制和临床应用技术 ,开辟了一条微创、简便、安全治疗屈膝挛缩的有效方法 ,能够矫正用传统手术难以治疗的严重膝关节屈曲僵直畸形