A novel radiographic analysis system for subaxial cervical spine pedicle screw placement.

BACKGROUND: Precise pedicle screw placement of the subaxial cervical spine is difficult. Not every hospital is equipped with a guidance system that can provide effective help. Computed tomography (CT) scanning is almost a routine preoperative examination for cervical spine surgery in all hospitals. Appropriate measurement and analysis of the CT images could assist optimal cervical pedicle screw placement. The purpose of this study is to propose a new and universal method using computed tomography (CT) morphological parameters analysis to assist optimal cervical pedicle screw placement from C3 to C7. METHODS: A localization system with six parameters was designed based on preoperative CT reconstruction to guide subaxial cervical spine pedicle screw placement. The six parameters were distance from the starting point to the midline [D1], distance from the starting point to the lower edge of the inferior articular process [D2], transverse section angle [TSA], sagittal section angle [SSA], pedicle width [PW], and pedicle height [PH]. The six parameters were analyzed in 53 participants. RESULTS: Combining D1 and D2 could localize the entrance of the pedicle screw, and we concluded that D1 and TSA and D2 and SSA could be a new standard for determination of the transverse and sagittal orientation of the pedicle screw. The six parameters were closely related to the patient's gender, height, and weight. PH and PW were linearly correlated and could guide selection of the appropriate pedicle screw. SSA was an independent parameter of the relevant vertebral body, and changes in SSA had nothing to do with the curvature or posture of the cervical spine. CONCLUSIONS: Understanding and applying the six-parameter localization system are essential for achieving accurate and optimal pedicle screw placement in subaxial cervical spine, regardless of cervical sagittal alignment.

Subdural fluid collection rather than meningitis contributes to hydrocephalus after cervical laminoplasty: A case report.

BACKGROUND: Hydrocephalus following dural tear after spinal surgery is rare. Although a few cases of obstructive hydrocephalus caused by subdural fluid collection and communicating hydrocephalus associated with meningitis have been reported, the mechanism remains uncertain. Herein we describe a patient complicated with hydrocephalus after cervical laminoplasty in whom subdural fluid collection in the cervical spine and posterior cranial fossa rather than chronic meningitis was the main mechanism. CASE SUMMARY: A 45-year-old man underwent cervical laminoplasty for cervical spondylotic myelopathy at a local hospital. Ten days postoperatively, a high fever occurred and magnetic resonance imaging (MRI) showed cerebrospinal fluid (CSF) leakage. Pseudomeningocele liquid test showed high levels of protein and white blood cell (WBC) count with negative bacterial culture. The patient was treated with short-term intravenous antibiotic and discharged with normal body temperature. The patient was uneventful during the first 8 mo follow-up although repeated MRI showed persistent pseudomeningocele. At the 9th mo postoperatively, the patient gradually presented with dizziness and headache accompanied by recurrent weakness of his left arm. Imaging examinations demonstrated hydrocephalus and a cystic lesion around the cervical spinal cord. CSF test from lumbar puncture indicated chronic meningitis. MRI on 1 d after pseudomeningocele drainage showed a significant decrease in the cystic volume, suggesting that the cystic lesion would be subdural fluid collection rather than adhesive arachnoiditis. After dural defect repair, the patient's symptoms completely resolved and hydrocephalus gradually disappeared. CSF analysis at the 21-mo follow-up revealed significantly decreased protein level and WBC count. CONCLUSION: Subdural fluid collection rather than meningitis contributes to the hydrocephalus formation after cervical laminoplasty.

A novel system for accurate lumbar spine pedicle screw placement based on three-dimensional computed tomography reconstruction.

OBJECTIVES: The accuracy of pedicle screw placement strongly affects the outcome of spinal surgery and has mainly relied on the surgeons' experience. There is no simple, low-cost, and effective pedicle screw placement system to assist new spinal surgeons with less experience. METHODS: We designed a localization system with six parameters (starting point height [SP-H], starting point length [SP-L], transverse section angle, sagittal section angle [SSA], pedicle width [W] and height [H]) based on preoperative computed tomography reconstruction and combined it with the Roussouly classification to guide lumbar spine pedicle screw placement and analysed the change patterns of the six parameters in 50 participants. RESULTS: Based on the system, we confirmed that combining SP-H and SP-L can localize the entrance of the pedicle screw. Furthermore, we considered that SP-L and transverse section angle would be a new standard for determination of the transverse orientation of the pedicle screw. More importantly, the linear regression equations between H and W and SP-H and H were concealed. In addition, H and W can guide the appropriate selection of pedicle screw. Moreover, change patterns of SSA combined with the Roussouly classification indicate that SSA of L3 can be used as a benchmark to guide the establishment of sagittal alignment of the lumbar spine. CONCLUSIONS: Understanding and applying the six-parameter localization system are essential for achieving accuracy in lumbar spine pedicle screw placement, and the system is a useful guide in the establishment of sagittal alignment. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: This study provides a new pedicle-screw placement system for accurate lumbar spine pedicle screw placement based on three-dimensional CT reconstruction, requiring six parameters to guide the system.

Photochemical Tissue Bonding Technique for Improving Healing of Hand Tendon Injury.

PURPOSE: We utilized a novel approach of combined photochemical tissue bonding (PTB) and human amniotic membrane (HAM) to improve hand tendon repair and also evaluated its efficacy. METHODS: Subei chickens underwent surgical transection of the flexor digitorum profundus tendons and repair by (1) SR (standard Kessler suture; n = 24; 6-0 prolene) and (2) HAM/PTB (n = 24), where a section of HAM was stained with 0.1% Rose Bengal, wrapped around the ruptured tendon and bonded with 532 nm light (0.5 W/cm2, 200 J/cm2). Total active motion, gross appearance, extent of adhesion formation, biochemical properties, and inflammatory cells of the repaired tendon were evaluated on days 3, 7, 14, and 28 postoperatively. RESULTS: PTB strongly bonded HAM with flexor digitorum profundus tendon surface. No significant difference was observed between the tensile properties of either group on all postoperative time points. The joint activities and the adhesion formation levels were significantly better in the HAM/PTB group compared with those in the SR group on day 14. Histological examination revealed drastically reduced number of inflammatory cells in the HAM/PTB group than in the SR group on days 7 and 14 after surgery. CONCLUSIONS: These findings revealed that PTB sealing of HAM around the tendon repair site provided considerable benefits for hand tendon repair by eliminating technical difficulties and obvious contraindications. Thus, this novel procedure has considerable benefits in repairing hand tendon damage.

[Repair of skin and soft tissue defects of lower limbs with vacuum sealing drainage combined with flaps].

OBJECTIVE: To explore the feasibility, indications, and effects of vacuum sealing drainage (VSD) combined with flaps for repairing skin and soft tissue defects of lower limbs. METHODS: From June 2006 to November 2009, 15 patients with skin and soft tissue defects of lower limbs were treated with VSD combined with flaps (VSD group, n = 5) and only flaps (non-VSD group, n = 10). In VSD group, there were 3 males and 2 females with an average age of 46 years (range, 32-69 years), including 3 cases of traffic accident injury, 1 case of skin necrosis after amputation, and 1 case of plate exposure after operation. The locations were lower leg in 1 case, ankle in 2 cases, dorsum of foot in 1 case, and forefoot in 1 case. The defect size ranged from 6.5 cm x 6.0 cm to 23.0 cm x 17.0 cm. The disease course ranged from 2 hours to 2 months. In non-VSD group, there were 5 males and 5 females with an average age of 50 years (range, 23-58 years), including 6 cases of traffic accident injury, 1 case of crush injury in earthquake, 1 case of osteomyelitis, and 2 cases of plate exposure after operation. The locations were lower leg in 1 case, ankle in 3 cases, forefeet and dorsum of feet in 4 cases, and heel in 2 cases. The defect size ranged from 4 cm x 4 cm to 20 cm x 12 cm. The disease course ranged from 1 hour to 2 months. There was no significant difference in general data between 2 groups (P > 0.05). RESULTS: In VSD group, the preoperative hospitalization days, postoperative hospitalization days, and total hospitalization days were (11.8 +/- 9.5), (35.4 +/- 28.3), and (47.2 +/- 35.8) days, respectively; the size of flap was (232.8 +/- 142.0) cm2; and the infection rate after VSD-use was 0. In non-VSD group, the preoperative hospitalization days, postoperative hospitalization days, and total hospitalization days were (25.8 +/- 12.4), (33.9 +/- 28.1), and (59.7 +/- 32.4) days, respectively; the size of flap was (97.3 +/- 93.6) cm2; and the infection rate after 8 to 14 days of regular therapy was 80%. There were significant differences in the preoperative hospitalization days and the size of flap between 2 groups (P < 0.05). All flaps were alive except 3 partial necrosis (1 case in VSD group, 2 cases in non-VSD group). The 3 flaps healed by skin grafting and suturing. The donor sites healed by first intention. All patients were followed up 5-41 months (22.1 months on average). All flaps were good in color, texture, and wear ability. CONCLUSION: It is effective to apply VSD combined with proper flap to repair skin and soft tissue defects of lower limbs, which can cut down infection rate, improve blood supply, shorten the preoperative hospitalization days, and facilitate healing, but whether it can shorten the postoperative hospitalization days and total hospitalization days need further research.