Adjacent segment degeneration after single-segment PLIF: the risk factor for degeneration and its impact on clinical outcomes.

PURPOSE: To investigate: (1) the risk factors for radiologic cranial adjacent segment degeneration (ASD) after single-segment PLIF at the same level, and (2) the impact of the ASD on the clinical outcomes. METHODS: From October 2004 to May 2009, 109 patients who underwent PLIF for degenerative instability at L4/5 and have more than 2 years follow-up were studied retrospectively. We measured the preoperative bone mineral density (BMD), lumbar lordosis, the lumbosacral joint angle, the lumbar inclination, the height and the dynamic angulation of the intervertebral space at the fused segments and the upper adjacent segment, the sliding displacement between L3 and L4. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) score and the Oswestry Disability Index (ODI). Patients were divided into two groups according to the progression of L3-L4 degeneration: Group A without progression of L3-L4 degeneration, Group B with progression of L3-L4 degeneration. Clinical outcomes and radiologic measurement index between the two groups were compared, and the risk factors for progression of L3-L4 degeneration were analyzed. The correlation between clinical outcomes and progression of L3-L4 degeneration were also investigated. RESULTS: There were 11 patients (22%) classified into Group A. No significant difference was found between the two groups in terms of the lordosis angle at L1 and S1, the laminar inclination at L3, the pre-existing L3-L4 disk degeneration, the lordosis angle of L4-L5, the lumbosacral joint angle and preoperative BMD (P > 0.05). Significant differences were found between the two groups in age. No significant difference was found between the two groups in the ODI and the JOA score at the final follow-up (P > 0.05). CONCLUSION: Radiologic degeneration of the cranial adjacent segment after single-segment PLIF did not significantly correlate with clinical outcomes. Age was a risk factor for radiologic degeneration, however, there was no significant correlation between degeneration and preoperative radiologic factors and bone mineral density (BMD).

Preserving the C7 spinous process with its muscles attached: effect on axial symptoms after cervical laminoplasty.

BACKGROUND: Many efforts to reduce axial symptoms after cervical laminoplasty have been tried and reported; nevertheless, avoiding the axial symptoms has not yet been solved. There have been some reports that preserving the muscles attached to the C7 spinous process could reduce axial symptoms. The purpose of this study was to investigate whether axial symptoms can be reduced by preserving the C7 spinous process with its muscles attached during cervical laminoplasty. METHODS: A series of 21 patients (group A) with C4-6 laminoplasty, preserving the C7 spinous process and its attached muscles, were compared with 22 patients (group B) with C4-7 laminoplasty. The axial symptoms (incidence, intensity, severity), cervical mobility, cervical curvature morphology, cross-sectional area of posterior cervical muscles, and Japanese Orthopaedic Association (JOA) score were evaluated. RESULTS: There were no significant differences in incidence, intensity, or severity of axial symptoms 1 year after operation. In addition, there were no significant differences in the cervical mobility or curvature morphology, the cross-sectional area of the posterior cervical muscles, or the JOA score. CONCLUSIONS: These results suggest that both preserving and not preserving the C7 spinous process with its muscles attached during cervical laminoplasty are acceptable in the long term.

Preliminary Application of One-level Posterior Lumbar Interbody Fusion with Prospace and Facet Fusion Using Local Autograft / 中国修复重建外科杂志

Objective To evaluate the safety and efficacy of one-level posterior lumbar interbody fusion(PLIF) combined with Prospace and facet fusion using local autograft. Methods Clinical and radiographic data of 76 patients treated by this technique was reviewed from May 2002 to December 2004. Of them, there were 52 males and 24 females, with an average age of 53.2 years (23-81 years), including 60 cases of degenerative disc disease, 9 cases of failed back surgery syndrome and 3 cases of spondylolysis. The disese courses were 1.2-8.7 years (mean 3.6 years). The levels of PLIF were: L2,3 in 2 cases, L3,4 in 7, L4,5 in 54, L5/S1 in 10, L4/S1 in 1 and L5,6 in 2. After decompression, Prospace was inserted into interbody space bilaterally,and located in disc space 4 mm beyond the rear edge of the vertebral body. Local laminectomy autograft was packed both laterally into and between 2 implants. Then the remanent local autograft was placed over facet bed. Pedicle screws were used after insertion of Prospace. Clinical results were evaluated by the JOA score. Disc height ratio and lumbar lordosis angles were measured on lateral radiographs. Fusion status was determined by evidence of bridge trabeculae across facet joint and interbody space on CT scan without mobility in lateral dynamic X-rays, and no radiolucent gap between Prospace and endplate. Paired t-test was used for statistical analysis. Results Mean blood loss and operative time was 384 ml and 178 minutes, respectively. The average JOA score at final follow-up (26.1 + 2.7) was significantly improved when compared with that of pre-operation (14.5 ± 4.0, P ＜ 0.05), with a mean recovery rate of JOA score 81.1% (37.5%-100.0%). The fusion rate was 97.4% (74/76). Mean disc height ratio and the involved segmental lordosis angle were increased from preoperative 0.27 ±0.07 and 5.8 + 2.2° to 0.33 + 0.06 and 11.3 + 2.0° respeetively at the final follow-up, and the differences were significant ( P ＜ 0.05). There were no device-related complications. Conclusion This surgical technique combined with Prospace interbody device is a safe and effective surgical option for patients with one-level lumbar disorders when PLIF is warranted.

Inadvertent C2-C3 union after C1-C2 posterior fusion in adults.

INTRODUCTION: Some authors pointed out that there were more than a few patients with inadvertent C2-C3 union after C1-C2 posterior fusion, although few detailed studies of C2-C3 union have been reported. The purpose of this study was to clarify whether C2-C3 union accelerated adjacent C3-C4 disc degeneration after C1-C2 posterior fusion and to investigate the related factors for C2-C3 union. METHODS: Sixteen patients with rheumatoid arthritis (RA group) (4 males, 12 females, mean age 60 years, mean follow-up period 4 years and 3 months) and fifteen patients without RA (non-RA group) (11 males, 4 females, mean 52 years, mean follow-up period 3 years and 10 months) who underwent C1-C2 posterior fusion were radiologically assessed. The C2-C3 union was defined as trabecular bone formation at C2-C3 interlamina in lateral radiograph. C3-C4 disc height was measured to evaluate the disc degeneration. RESULTS: C2-C3 union rate was 56% and 60% in RA group and non-RA group, respectively. In RA group, postoperative C3-C4 disc height was lower (Student's t-test, P = 0.029) and the decrease rate of C3-C4 disc height was higher (Student's t-test, P = 0.015) in patients with C2-C3 union than in patients without C2-C3 union. In non-RA group, the age at operation was older (Student's t-test, P = 0.0007), and the C1-C2 fusion angle (Student's t-test, P = 0.012) was smaller in patients with C2-C3 union than in patients without C2-C3 union. CONCLUSIONS: C2-C3 union after C1-C2 posterior fusion occurred in more than half of both groups. Inadvertent C2-C3 union should be considered a radiological complication and a potential risk factor due to acceleration of C3-C4 disc degeneration in RA.

Correlation between severity of rheumatoid arthritis and manner and extent of cervical lesion.

Abstract To determine the proper management of treatment for rheumatoid cervical lesions, we investigated the clinical course of the cervical spine in rheumatoid arthritis (RA). The severity of RA was classified into three groups according to the disease subsets advocated by Ochi et al.: the less erosive subset (LES), the more erosive subset (MES), and mutilating disease (MUD). Then the following radiographic assessments were performed on cervical roentogenograms: atlantoaxial subluxation (AAS), vertical subluxation (VS), and subaxial subluxation (SAS). One hundred and seventy-four patients were available for this study. The mean age of the patients was 60.9 years (19-85 years). The average duration from the onset of RA was 19.1 years (10-40 years). Eighty-seven patients were classified as LES, 69 were MES, and 18 were MUD. We found that few patients in the LES group had required an operation on the cervical spine. AAS was seen in about 60% of the MES patients, but few cases had VS or SAS, and most operations were atlantoaxial fusion. All patients in the MUD group had some cervical instabilities. Not only VS but also SAS were seen in more than half of these patients, and many patients had required occipitothoracic fusion.