Release, reduction, and fixation of one-stage posterior approach for basilar invagination with irreducible atlantoaxial dislocation.

PURPOSE: We evaluate the efficacy, safety and indications of single stage posterior release, reduction, and fixation of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD). MATERIALS AND METHODS: Seventeen patients with BI and IAAD consecutively underwent one-stage release, reduction, and fixation by a posterior approach from July 2000 to June 2015 were followed up for at least 12 months. There were 8 males. Mean age was 56 35.2 ± 13.8 years (range 12-56). The clinical symptoms and signs of the patients were recorded. Pre- and postoperative imaging examinations were performed. Neurological function was assessed using the Japanese Orthopedic Association (JOA) and Ranawat scores. RESULTS: Average follow-up time was 47.4 months (12-97 months). The JOA score increased from preoperative 4-10 (8.06 ± 2.52) to postoperative 13-16 (15.20 ± 0.62). The preoperative Chamberlain line, McRae line, Wackenheim line, atlantodens interval, and cervico medullary angle were 12.52 ± 5.17 mm, 6.59 ± 3.04 mm, 6.96 ± 4.32 mm, 9.88 ± 1.93 mm, and 115.35 ± 12.40°, respectively. The postoperative values were 2.0 ± 3.67 mm, -3.06 ± 1.85 mm, -1.76 ± 2.88 mm, 1.17 ± 1.18 mm, and 136.76 ± 11.44°, respectively. CONCLUSION: One-stage release, reduction, and fixation for patients with BI and IAAD through a posterior approach is safe and efficient.

[Clinical characteristics and treatment for patients with low back and leg pain caused by lumbar annular tears].

OBJECTIVE: To investigate whether annular tears is a cause of low back and radiating leg pain and explore the clinical characteristics and treatment for patients with this condition. METHODS: A total of 34 patients with low back and radiating leg pain, but without lumbar disc herniation on CT (computed tomography) or MRI (magnetic resonance imaging), were examined by electrophysiological studies and discography to identify whether there were or not annular tears and nerve root injury and decipher the relations between them. The series included 15 males and 19 females with an average age of 45.6 years old and the average duration of symptoms was 25.8 months. All patients with annular tears and positive pain provocation test were treated by local windowing decompression and debridement of nucleus pulposus after failed conservative treatment. The pre- and post-operative functions and pain were evaluated by JOA (Japanese Orthopedic Association) and VAS (visual analog scale) scores respectively. The average follow-up was 17.4 months. RESULTS: The clinical manifestations included low back and radiating leg pain, intermittent claudication and nerve root injury. No significant abnormalities were discovered on X-ray and CT scan. T2W images of magnetic resonance demonstrated a low intensity or black disc in all patients and high-intensity zone (HIZ) (n = 21). Electromyography showed nerve root injury (n = 27). Abnormality of conduction velocities of common peroneal nerve (n = 7) and tibial nerve (n = 3) were found. Thirty-four patients with 38 discs displayed pain reproduction on contrast injection during discography and the sites of annular tears were confirmed on CT scan after discography. Pre- and post-operative average JOA scale score was 8.7 points and 13.5 points, the recovery ratio 76.2% and the excellent and good outcomes 88.2%. Pre- and post-operative average VAS score was 8.6 points and 2.8 points. And the recovery rate was 80.5%. CONCLUSION: The annular tears result in low back and radiating leg pain. And the typical characteristics are low back and radiating leg pain, intermittent claudication and nerve root injury. MRI and electrophysiological studies play an important role in diagnosing this condition. Lumbar discography is the decisive method and prerequisite of selecting surgery. Local windowing decompression and debridement of nucleus pulposus is a simple and effective method.

[Intraobserver and interobserver reliability of the King, Lenke, and PUMC classification systems for idiopathic scoliosis].

OBJECTIVE: To evaluate the intraobserver and interobserver reliability and main influencing factors of the King, Lenke, and PUMC classification systems for idiopathic scoliosis (IS) using radiographs that had not been premeasured. METHODS: Fifty-six patients with IS, 9 male and 47 female, aged 15.4 (11 - 18), underwent preoperative X-ray photography of spine standing full-length posteroanterior and lateral films and left and right supine side-bending radiographs. The films were read by four orthopedic surgeons independently to do measurement and typing according to the King, Lenke, and PUMC classification systems respectively. Two weeks later, the sequence of the X-ray films was re-ordered and the 4 surgeons read them and did measurement and typing once more. The average percentage of intraobserver and interobserver agreement was calculated. Kappa coefficients were used to determine the intraobserver and interobserver reliability. RESULTS: King classification demonstrated fair interobserver reliability and excellent intraobserver reliability. The mean interobserver reliability was 65.8% (Kappa coefficient = 0.542), while the intraobserver reliability was 82.6% (Kappa coefficient = 0.767). The main reason of disagreement was distinguishment of the King type II and type III. Another reason was assessment of King type V. The complete Lenke classification demonstrated poor reliability. The mean interobserver reliability was 50.0% (Kappa coefficient = 0.438), and the intraobserver reliability was 47.0% (Kappa coefficient = 0.402). The 3 components of Lenke classification had fair interobserver and intraobserver reliability when they were examined separately. The main reasons for disagreement arose from judging whether there was a structural upper thoracic curve and assigning sagittal thoracic modifier. The PUMC type demonstrated excellent intraobserver and interobserver reliability with a mean interobserver reliability of 87.8% (Kappa coefficient = 0.757), and a mean intraobserver reliability of 92.9% (Kappa coefficient = 0.958). Its subtypes demonstrated fair agreement with the mean interobserver reliability of 70.2% (Kappa coefficient = 0.629), and a mean intraobserver reliability of 74.1% (Kappa coefficient = 0.674). The main reasons for disagreement were definition of a curvature and Cobb angle measurement. CONCLUSION: King and PUMC classification systems have higher interobserver and intraobserver reliability than Lenke classification. The reliability levels of the 3 classification systems are all influenced by many factors. Judgment of an upper thoracic curve, variable of Cobb angle measurement, and relationship of the central vertical sagittal line to apex of curve are the common reasons for disagreement in these 3 classifications.

Selection of surgical procedures for basilar invagination with atlantoaxial dislocation.

BACKGROUND CONTEXT: Basilar invagination (BI) is a malformation of craniovertebral junction. However, surgical procedures on BI with atlantoaxial dislocation (AAD) remain controversial. PURPOSE: This research aimed to investigate the selection of surgical procedures and its significance in the surgical treatment of patients with BI and AAD. STUDY DESIGN: This was a retrospective study. PATIENT SAMPLE: This study enrolled 33 patients who were diagnosed with BI and AAD and were followed up for at least 6 months. OUTCOME MEASURE: All of the patients were assessed for neurologic recovery observation in terms of Japanese Orthopaedic Association scores and Odom criteria. X-ray, magnetic resonance imaging, or computed tomography scanning was used to determine reduction, compression, bone graft, and internal fixation before and after operation. METHODS: Thirty-three patients who suffered from BI with AAD were treated in our department from July 2000 to October 2014. Preoperatively, the patients were divided into two types on the basis of whether dislocation was reduced after anesthesia and traction were performed: reducible dislocation (Type A) and irreducible dislocation (Type B). Reducible dislocation was further divided into two subtypes: full reducible dislocation (Type A1) and partial reducible dislocation (Type A2). Type A1 patients were treated with direct posterior fixation and fusion after traction and reduction. Type A2 patients received posterior atlantoaxial release, fixation, and fusion under traction. Type B patients underwent transoral atlantoaxial release, posterior fixation, and fusion. RESULTS: There were 5 Type A1 patients, 10 Type A2 patients, and 18 Type B patients treated in accordance with the proposed scheme. Postoperatively, sufficient reduction and decompression were achieved for all cases. Two Type B patients died. Other patients were followed up from 6 months to 42 months (average=16.6 months); follow-up results showed sufficient decompression, effective fixation and fusion, and no reduction loss. The Japanese Orthopaedic Association Score increased from preoperative 4-12 (average, 7.8) to postoperative 10-17 (average, 14.3), and neurologic recovery was satisfactory. CONCLUSIONS: Under traction, simple posterior fixation and fusion were effective for Type A patients suffering from BI with AAD; anterior atlantoaxial release and posterior fixation and fusion were effective for Type B patients with BI and AAD.

[Spinal wedge osteotomy by posterior approach for correction of severe rigid scoliosis].

OBJECTIVE: To introduce operation skill of the spinal wedge osteotomy by posterior approach for correction of severe rigid scoliosis and to discuss the selection of the indications and the range of fusion and fixation. METHODS: Between July 1999 and January 2009, 23 patients with severe rigid scoliosis were treated with spinal wedge osteotomy by posterior approach, including 16 congenital scoliosis, 5 idiopathic scoliosis, and 2 neurofibromatosis scoliosis. There were 11 males and 12 females with a median age of 15 years (range, 8-29 years). Two patients had previous surgery history. The Cobb's angles of scoliosis and kyphosis before operation were (85.39 +/- 13.51) degrees and (56.78 +/- 17.69) degrees, respectively. The mean spinal flexibility was 14.4% (range, 4.7%-22.5%). The trunk shift was (15.61 +/- 4.89) mm. The preoperative CT or MRI showed bony septum in the canal in 2 patients. RESULTS: The mean operative time was 241 minutes and the mean blood loss was 1 452 mL. The average fused vertebrae were 10.7 segments (range, 8-14 segments). The follow-up ranged from 1 to 4 years with an average of 2 years and 6 months. The postoperative Cobb's angle of scoliosis was (38.70 +/- 6.51) degrees, the average correction rate was 54.7%. The postoperative Cobb's angle of kyphosis was (27.78 +/- 6.01) degrees, the average correction rate was 51.0%. The trunk shift was improved to (4.69 +/- 1.87) mm, the increased height was 5.2 cm on average (range, 2.8-7.7 cm). The Cobb's angle of scoliosis was (41.57 +/- 6.80) degrees with an average 2.9 degrees loss of correction at the final follow-up; the Cobb's angle of kyphosis was (30.39 +/- 5.94) degrees with an average 2.6 degrees loss of correction at the final follow-up; the trunk shift was (4.78 +/- 2.00) mm at the final follow-up. There were significant differences (P < 0.05) in the Cobb's angles of scoliosis and kyphosis and the trunk shift between preoperation and postoperation, between preoperation and last follow-up. Four cases had pedicle fracture, 1 had Li nerve root injury, 2 had superior mesenteric artery syndrome, 1 had exudates of incision, and 2 had temporary dysfunction of both lower extremity. CONCLUSION: Spinal wedge osteotomy by posterior approach is a reliable and safe surgical technique for correcting severe rigid scoliosis. With segmental pedical screw fixation, both the spinal balance and stability can be restored.