颈椎后纵韧带骨化症合并硬膜囊骨化的前路手术治疗

目的 探讨颈椎后纵韧带骨化症合并硬膜囊骨化的影像学表现、前路手术方法 及疗效.方法 2005年1月至2008年3月,前路手术治疗颈椎后纵韧带骨化症合并硬膜囊骨化患者13例.男11例,女2例;年龄43～72岁,平均53.6岁.骨化物分型:局限型3例,分节型2例,连续型5例,混合型3例;骨化物范围涉及1～5椎,平均2.8椎.患者均通过前路椎体次全切除术,切除骨化后纵韧带减压,术中6例患者后纵韧带骨化和硬膜囊骨化得以完全分离,硬膜囊保留完整,另7例患者硬膜囊出现不同程度撕裂或缺损.结果 8例患者术前CT横断面成像上表现为典型的"双影征",2例患者表现为整块骨化物存在中心低密度影,余3例患者表现为椎管狭窄率超过90%的严重后纵韧带骨化.术后5例患者并发脑脊液漏,其中3例经卧床休息、局部加压治疗3～5 d后愈合,另2例患者皮肤愈合后形成间歇性脑脊液囊肿,经反复穿刺抽液治疗1个月后痊愈.随访6个月～2年,平均1年,所有患者JOA评分从术前平均8.1分提高至术后平均13.2分,神经功能恢复率平均57.3%.骨化硬膜囊切除和未切除两组患者的神经功能恢复率差异无统计学意义.结论 CT三维重建检查有助于术前诊断后纵韧带骨化合并硬膜囊骨化,合并硬膜囊骨化并非前路手术的禁忌证,前路手术切除骨化后纵韧带、彻底减压是提高此类患者手术疗效的关键.     

Biomorphometric analysis of ilio‐sacro‐iliacal corridors for an intra‐osseous implant to fix posterior pelvic ring fractures

It is hypothesized that ilio‐sacro‐iliacal corridors for a new envisioned pelvic ring implant (trans‐sacral nail with two iliacal bolts = ISI‐nail: ilio‐sacro‐iliacal nail) exists on the level of S1‐ or S2‐vertebra in each patient. The corridors of 84 healthy human pelves (42x ♂; 42x ♀, 18–85 years) were measured in high resolution CT scans using the Merlin Diagnostic Workcenter Software. Trans‐sacral corridors (≥9 mm diameter) on the level of S1 and S2 were found in 62% and 54% of pelves with a mean length [mm ± SD] of 164 ± 12.9 and 142 ± 10.2. Corresponding iliac corridors were present in all specimens in caudally tilted axial planes of 37.8 ± 0.67° and 53.7 ± 0.94° in relation to the operating table plane and divergent angulations of 69.0 ± 0.49° and 70.1 ± 0.32° in relation to the sagittal midline plane. Sacral dysmorphism, with compensatory larger S2 corridors were prevalent in 24% of pelves; ilio‐sacro‐iliacal osseous corridors for the envisioned implant were found in 88% of pelves on the level of S1 or S2. In the remaining 12% with too narrow corridors for any trans‐sacral implant (screws, bars, ISI nail) alternative fixation methods have to be considered. Expected advantages of the envisioned ISI nail compared to available fixation devices are discussed. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:254–260, 2015.

     

A novel approach for intra‐operative shape acquisition of the tibio‐femoral joints using 3D laser scanning in computer assisted orthopaedic surgery

Background

Image registration (IR) is an important process of developing a spatial relationship between pre‐operative data and the physical patient in the operation theatre. Current IR techniques for Computer Assisted Orthopaedic Surgery (CAOS) are time consuming and costly. There is a need to automate and accelerate this process.

Methods

Bespoke quick, cost effective, contactless and automated 3D laser scanning techniques based on the DAVID Laserscanner method were designed. 10 cadaveric knee joints were intra‐operatively laser scanned and were registered with the pre‐operative MRI scans. The results are supported with a concurrent validity study.

Results

The average absolute errors between scan models were systematically less than 1 mm. Errors on femoral surfaces were higher than tibial surfaces (P<0.05). Additionally, scans acquired through the large exposure produced higher errors than the smaller exposure (P<0.05).

Conclusion

This study has provided proof of concept for a novel automated shape acquisition and registration technique for CAOS.     

A comparison of published rates of resection margin involvement and intra‐operative perforation between standard and ‘cylindrical’ abdominoperineal excision for low rectal cancer

Aim The study aimed to compare recent reports on standard and alternative methods of abdominoperineal excision for low rectal cancer regarding the rates of circumferential resection margin involvement and intra‐operative bowel perforation. Method Data on rates of margin involvement and perforation were obtained from eight recently published reports and also from a prospective registry of resections at Concord Hospital. Rates of these outcomes and their 95% confidence intervals were evaluated. Results There was no evidence that extralevator abdominoperineal excision yielded significantly lower rates of resection margin involvement or intra‐operative bowel perforation compared with standard abdominoperineal excision in six independent hospital‐ and population‐based patient series. Abdominosacral resection of the rectum, on the other hand, did show significantly lower rates of these endpoints, albeit in selected patients. Conclusion The role of extralevator abdominoperineal excision and abdominosacral resection of the rectum should be investigated further in randomized controlled trials.     

Dynamic contrast enhanced‐magnetic resonance imaging study of the nutrition pathway for lumbar intervertebral disk cartilage of normal goats

Objective: Study of the nutrition pathway for lumbar intervertebral disk cartilage of normal goats. Methods: Four lumbar intervertebral disks from each of eight 24‐month‐old goats (32 disks) were studied. After the goats had been anesthetized, signal intensity changes in the regions of interest (ROI) were observed by dynamic contrast enhanced magnetic resonance scanning. Before and after enhancement at the time points of 0, 5, 10, and 30 mins, and 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 hs, the ROI signal intensity was measured, and the time‐signal intensity curve and peak times analyzed. Results: Signal intensity in the vertebral bodies reached a peak at 0 min and decreased quickly thereafter. Signal intensity in the cartilage endplate zones reached the first peak at 30 mins and then went down slightly before increasing to a second peak at 2 hs. Signal intensity in the nuclei pulposus was negative within 5 mins, increased slowly to a peak at 2 hs, and declined thereafter. Conclusion: Nutrient metabolism of the lumbar intervertebral disks of normal goats occurs mainly through the cartilage end‐plate pathway.     

Combination therapy with intra‐articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit

The present study investigated intra‐articular injection of bone‐marrow‐derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight‐bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra‐articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra‐articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1466–1473, 2015.