Computer-assisted fluoroscopic navigation of percutaneous spinal interventions

Purpose

Percutaneous spine procedures may occasionally be difficult and subject to complications. Navigation using a dynamic reference base (DRB) may ease the procedure. Yet, besides other shortcomings, its fixation demands additional incisions and thereby defies the percutaneous character of the procedure.

Methods

A new concept of atraumatic referencing was invented including a special epiDRB. The accuracy of navigated needle placement in soft tissue and bone was experimentally scrutinised. Axial and pin-point deviations from the planned trajectory were investigated with a CT-based 3D computer system. Clinical evaluation in a series of ten patients was also done.

Results

The new epiDRB proved convenient and reliable. Its fixation to the skin with adhesive foil provided a stable reference for navigation that improves the workflow of percutaneous interventions, reduces radiation exposure and helps avoid complications.

Conclusions

Percutaneous spine interventions can be safely and accurately navigated using epiDRB with minimal trauma or radiation exposure and without additional skin incisions.     

微创和开放TLIF治疗单节段腰椎间盘突出症的比较

目的评价即时三维导航下单节段微创经椎间孔椎体融合术（minimallytransforaminallumbarinterbodyfu．sion,mini—TLIF）与开放后路（openposteriortransforaminallumbarinterbodyfusion,open—TLIF）的短期临床疗效比较。方法2011年10月至2012年2月对40例单节段腰椎间盘突出症患者分别采用即时三维导航下mini—TLIF（20例）和open—TLIF（20例）术式进行对比研究。比较两组手术时间、术中出血量、术后引流量、术后住院时间与总住院时间。视觉模拟评分（visualanaloguescale,VAS）和日本骨科协会（Japaneseorthopaedicassociation,JOA）下腰痛评分评价术后伤口疼痛及功能情况。结果4｜D例均获得随访,mini—TLIF组平均手术时间较open—TLIF组长,差异有统计学意义（P〈0．01）,mini—TLIF组总的住院时间、术后住院的时间较open—TLIF组明显缩短,差异有统计学意义（P〈0．01）;mini—TLIF组术中出血量明显较open—rrIJIF组减少,差异有统计学意义（P〈0．05）;术后引流量明显较open—TLIF组减少,差异有统计学意义（P〈0．01）;术后3dmini—THF组腰痛VAS评分的降低更为明显,差异有统计学意义（P〈0．01）;术后3dmini—TLIF组JOA评分同open—TLIF组比较下降更为明显,差异有统计学意义（P〈O．01）。术前、术后6个月两组腰、腿痛VAS评分、JOA评分比较,差异无统计学意义（P〉0．05）。结论即时三维导航下单节段微创TLIF具有术中出血量少、术后引流少、创伤小、住院时间短、短期疗效确切等优点,是一种有效的治疗方法。     

磁力导航交锁髓内钉治疗胫骨干骨折

目的评价磁力导航交锁髓内钉治疗胫骨干骨折的疗效,并与普通交锁髓内钉疗效进行比较。方法将60例胫骨干骨折患者随机分为两组：A组30例,使用磁力导航交锁髓内钉治疗;B组30例,使用普通交锁髓内钉治疗。记录两组远端2枚锁钉锁定成功时间,一次性锁定成功率。对两组分别就其平均手术时间、骨折平均愈合时间、HSSkneeratingscore法评定功能的各项指标进行比较分析。结果远端2枚锁钉锁定成功时间：A组（7．9±3．7）min,B组（18．1±4．8）rain,两组差异有统计学意义（t=15．78,P〈0．05）;一次性锁定成功率：A组97％,B组78％．两组差异有统计学意义（t=10．01,P〈0．05）;A组骨折延迟愈合1例,骨折短缩移位1例;B组断钉1例,伤口浅表感染l例,骨折延迟愈合3例。两组手术时间、术中出血量、并发症及HSSkneeratingscore法评定功能恢复优良率比较,差异有统计学意义（t=17．32,14．75,7．46,P〈0．05）。结论磁力导航交锁髓内钉治疗胫骨干骨折疗效满意,与普通交锁髓内钉比较有定位准确、手术时间短、创伤小的优势。     

Comparison of Radiation Exposure in Lumbar Pedicle Screw Placement With Fluoroscopy Vs Computer-Assisted Image Guidance With Intraoperative Three-Dimensional Imaging

Background/objective: Little is known about the long-term effects of chronic exposure to ionizingradiation. Studies have shown that spine surgeons may be exposed to significantly more radiation than thatobserved in surgery on the appendicular skeleton. Computer-assisted image guidance systems have beenshown in preliminary studies to enable accurate instrumentation of the spine. Computer-assisted image guidance systems may havesignificant application to the surgical management of spinal trauma and deformity. The objective of this study was to compare C-arm fluoroscopy and computer-assisted imageguidance in terms of radiation exposure to the operative surgeon when placing pedicle screw-rod constructsin cadaver specimens.

Methods: Twelve single-level (2 contiguous vertebral bodies) lumbar pedicle screw-rod constructs (48screws) in 4 fresh cadavers were placed using standard C-arm fluoroscopy and computer-assisted imageguidance (Stealth Station with lso-C^3D ).Pedicle screw-rod constructs were placed at L1-L2, L3-L4, and L5-S1 in 4 fresh cadaver specimens. Imaging was alternated between C-arm fluoroscopy and computer-assistedimage guidance with Stealth Station lso-C^3D. Radiation exposure was measured using ringand badge dosimeters to monitor the thyroid, torso, and index finger. Postprocedure CT scans were obtained to judge accuracy of screw placement.

Results: Mean radiation exposure to the torso was 4.33 ± 2.66 mRemfor procedures performed with standard fluoroscopy and 0.33 ± 0.82 mRem for procedures performed with computer-assisted image guidance. This difference was statistically significant (P = 0.012). Radiation exposure to the index finger and thyroid was negligible for all procedures. The accuracy of screw placement was similar for both techniques.

Conclusions: Computer-assisted image guidance systems allow for the safe and accurate placement ofpedicle screw-rod constructs with a significant reduction in exposure to ionizing radiation to the torso of theoperating surgeon.