[The evaluation of posterior ligament complex injury as well as the analysis of its effects in thoracic-lumbar fractures].

OBJECTIVES: To evaluate and analyze the role of posterior ligament complex (PLC) in determining therapeutic principle for traumatic thoracic-lumbar fracture. METHODS: From August 2005 to May 2008, 60 patients (38 male, 22 female) who suffered from the traumatic thoracic-lumbar fracture were carried out posterior operations. According to the Magerl traumatic thoracic-lumbar fracture classification system, these cases were classified to subtype A, B and C. The average age was 34 years (21 - 65 years). Magnetic resonance imaging (MRI) scan, which including both T1/T2 weight and fat-stir sequence, as well as the MRI negative film reading technique were used to evaluate the state of PLC. Furthermore, related physical or neurological examinations (such as severe skin bruising and sinking, broadening spinous process gap and tenderness, spinal cord or nerve root injury) and another X-ray or CT reconstruction films were taken to evaluate the the state of PLC synthetically. Above-mentioned results were compared with the final exploration results during operation and some parameters were analyzed. RESULTS: The sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), misdiagnosis rate and rate of missed diagnosis of these sixty patients were 85.3%, 80.8%, 83.3%, 85.3%, 80.8%, 19.2%, 14.7% respectively. After 13 cases of thoracic-lumbar fracture-dislocation were eliminated, the sensitivity, specificity, accuracy, PPV, NPV, misdiagnosis rate and rate of missed diagnosis of remaining 47 cases were 81.0%, 80.8%, 80.9%, 77.3%, 84.0%, 19.2%, 19.0% respectively. There were 5 cases with MRI negative results before operation but positive results during operation. Contrarily, 5 cases with MRI positive results before operation but negative results during operation occurred. CONCLUSIONS: MRI is a main means for evaluating the state of PLC. Although the MRI fat-stir sequence as well as the MRI negative film reading technique are adopted, the state of PLC can not be estimated exactly before operation (especially for those unfracture dislocation cases). In order to estimate the state of PLC exactly, the related local physical examination and image technology as well as the location of the abnormal image signal in MRI film and time of injury must be analyzed synthetically.

[Experimental study of laparoscopical lumbar interbody fusion with polyporus composite phosphate calcium and rhBMP-2 compounds in sheep].

OBJECTIVE: To study the efficacy of polyporus composite phosphate calcium and rhBMP-2 compounds with laparoscopical lumbar interbody fusion in sheep. METHODS: Fourteen uniform-weight adult sheep were randomly divided into three groups for LA-5 interbody fusion with titanium mesh. Autogenous bone and titanium mesh was applied with open anterior technique in group 1 (n=4). In group 2, 4 sheep were operated with laparoscope technique for LA-5 interbody fusion with composite phosphate calcium (CPC) and titanium mesh. In group 3, 6 sheep underwent laparoscopical L4-5 interbody fusion with titanium mesh as well as polyporus composite phosphate calcium and rhBMP-2 compounds. At Weeks 6 and 12 post-operation, the sheep were sacrificed for imaging, biomechanic and morphological examinations. RESULTS: Although there was no statistical difference between open and laparoscopical interbody fusion group when comparing the remaining disc and endplate decorticated, bone fusion occurred in 3 groups after 3 months. A much larger amount of bony callus was observed earlier in laparoscopical L4-5 interbody fusion group with titanium mesh as well as polyporus composite phosphate calcium and rhBMP-2 compounds than two other groups. CONCLUSION: Polyporus composite phosphate calcium and rhBMP-2 compounds are suitable prosthetic materials for clinical trials. When these materials are utilized with a laparoscopical technique, satisfactory interbody fusion may be achieved.

[Selection of surgical methods for lumbar disc herniation with degenerative endplates changes].

OBJECTIVE: To analyze the selection of surgical methods for lumbar disc herniation with low back and leg pain and degenerative lumbar Modic endplate changes and their different postoperative therapeutic effects. METHODS: All 30 cases of single segment lumbar disc herniation accompanied by Modic endplate changes operated at our hospital using simple discectomy or decompressions with interbody fusion from January 2005 to January 2008 were retrospectively identified. There were 18 males and 12 females with an average age of 38.5 years old (26-53 years old) and an average follow-up of 21 months (4-40 months). RESULTS: Discectomy alone group included 15 cases. The average score of Japanese Orthopedics Association (JOA) and visual analysis scale (VAS) of low back pain and lower extremity radicular pain at the preoperative and final follow-up time was 13.2 (5-17), 6.8 (4-10), 4.8 (1-8) and 19.8 (14 -24), 4.8 (2-10), 1.2 (0-6) respectively. The average improvement rate of JOA was 41.9%. The difference of VAS of lower extremity radicular pain between pre and post-operation was 3.7 on average. Among these 15 cases, Modic I, II and I/II mixed-type was 5, 9, and 1 respectively. Decompression with interbody fusion group included 15 cases. VAS of low back pain and lower extremity radicular pain at the preoperative and final follow-up time was 12.9 (5-17), 7.0 (4-10), 4.9 (1-8) and 22.6 (19-28), 2.8 (2-8) and 1.3 (0-6) respectively. The average improvement rate of JOA was 63.4%. The differences of VAS of lower extremity radicular pain and low back pain between pre and post-operation were 4.3 and 3.6 on average respectively. Among these cases, Modic I, II and I/II mixed-type was 6, 8, and 1 respectively. Comparing the VAS of low back pain, JOA average score and the improvement rate of JOA score of two groups at pre-operation and post-operation, statistical analysis showed that decompression with interbody fusion group was superior to simple discectomy group. CONCLUSION: For lumbar disc herniation with degenerative Modic endplate changes, who suffered more from low back pain than lower extremity radicular pain, discectomy alone and decompression with interbody fusion could both improve the degree of lower extremity radicular pain, but discectomy alone is less likely to improve the degree of low back pain and function score than the latter. So the maneuver of lumbar decompression with fusion is a better choice.

Therapeutic strategy for traumatic instability of subaxial cervical spine.

BACKGROUND: A simple, safe and effective therapeutic strategy for traumatic instability of the subaxial cervical spine, as well as its prognostic assessment, is still controversial. METHODS: The therapeutic options for 83 patients of traumatic instability of the subaxial cervical spine, whose average age was 35 years, were determined, according to the Allen-Ferguson classification, general health and concomitant traumatic conditions, neurological function, position of compression materials, concomitant traumatic disc herniation/damage, concomitant locked-facet dislocation, the involved numbers and position, and the patients' economic conditions. An anterior, posterior or combination approach was used to decompress and reconstruct the cervical spine. No operations with an anterior-posterior-anterior approach were performed. RESULTS: The average follow-up was three years and nine months. Distraction-flexion and compression-flexion were the most frequent injury subtypes. There were 46, 28 and 9 cases of anterior, posterior and combination operations, respectively. The average score of the Japanese Orthopaedics Association, visual analog scale and American Spinal Cord Injury Association (ASIA) motor index improved from 11.2, 7.8 and 53.5, respectively, before operation, to 15.3, 2.6 and 67.8, respectively, at final follow-up. For incomplete spinal cord injury (SCI), the average ASIA neurological function scale was improved by 1-2 levels. Patients with complete SCI had no neurological recovery, but recovery of nerve root function occurred to different extents. After surgery, radiological parameters improved to different extents. Fusion was achieved in all patients and 12 developed complications. CONCLUSIONS: The best surgical strategy should be determined by the type of subaxial cervical injury, patients' general health, local pathological anatomy and neurological function.

[The retrospective analysis of surgical treatment for traumatic instability of sub-axial cervical spine].

OBJECTIVE: To evaluate and analyze a therapeutic principle and strategy to treat the traumatic instability of sub-axial cervical spine as well as the prognosis assessment. METHODS: According to the Allen-Fergurson's classification, 83 patients who suffered from the traumatic instability of sub-axial cervical spine were performed operations depending on the patients's general health, the local pathological anatomy and neurological function, including both the decompression and reconstruction maneuvers through anterior, posterior or combined approach. RESULTS: The average follow-up was 3 years and 9 months. The distraction-flexion and compression-flexion were the most frequent injury subtypes. There were 46, 28 and 9 operations through anterior, posterior or combined approach respectively. No operation through anterior-posterior-anterior approach occurred. The average scores of JOA, VAS and ASIA motor index improved from 11.2, 7.8 and 53.5 before operation, to 15.3, 2.6 and 67.8 at the final follow-up, respectively. After operation, there were different extent improvements of average radiologic parameter. Fusion was achieved in all patients and 12 complications occurred. CONCLUSIONS: According to both the patients's general health and the local pathological anatomy, individual therapeutic designing should be determined to treat the traumatic instability of sub-axial cervical spine.