Objective To investigate the effectiveness of surgical treatment for single-level degenerative lumbar instabil ity (DLI) by comparing traditional open transforaminal lumbar interbody fusion (TLIF) with minimally invasive TLIF. Methods Between March 2007 and May 2009，87 patients with single-level DLI were treated by traditional open TLIF (group A, n=45) and by minimally invasive TLIF (group B, n=42), respectively. There was no significant difference in gender, age, disease duration, segment level, combined diseases of lumbar spine, or the proportion of uni- and bilateral symptom between 2groups (P gt; 0.05). The indexes of surgical trauma，systemic inflammatory response, cl inical outcomes, and aravertebral muscle injury were compared between 2 groups. Results Operation was performed successfully in all patients. The patients were followed up 2.9 years on average in group A and 2.8 years on average in group B. The incision, blood loss, and postoperative drainage in group B were significantly less than those in group A (P lt; 0.05), but the operation time in group B was significantly longer than that in group A (P lt; 0.05). There were significant differences (P lt; 0.05) in C-reactive protein, leucocyte count, and creatine kinase MM between 2 groups at 24 hours postoperatively as well as in C-reactive protein at 6 days postoperatively; group B was superior to group A. At last follow-up, the Oswestry disabil ity index (ODI) and visual analogue score (VAS) were significantly improved when compared with the preoperative scores in 2 groups (P lt; 0.05). There were significant differences in ODI and back pain VAS score (P lt; 0.05), but no significant difference in leg pain VAS score (P gt; 0.05) between 2 groups. At last follow-up, no low back pain occurred in 8 and 18 cases, mild in 25 and 18 cases, moderate in 9 and 6 cases, and severe in 3 and 0 cases in groups A and B, respectively, showing that low back pain was significantly l ighter in group B than in group A (Z= —2.574, P=0.010). At last follow-up, the atrophy ratio of multifidus muscle was 37% ± 13% in group A and was 15% ± 7% in group B, showing significant difference (t=12.674, P=0.000). The multifidus muscle atrophy was rated as grade I in 18 and 44 sides, as grade II in 42 and 32 sides, and as grade III in 30 and 8 sides in groups A and B, respectively, showing significant difference (Z= — 4.947, P=0.000). Conclusion Both traditional open TLIF and minimally invasive TLIF are the effective treatments for single-level DLI. Minimally invasive TLIF has less surgical trauma, sl ighter postoperative systemic inflammatory response, less paravertebral muscle injury, and lower incidence of postoperative back pain, but it has longer operation time.
Objective To evaluate the cl inical outcomes and values of anterior segmental decompression and double-plate fixation (ASDDF) for treatment of ski p cervical spondylotic myelopathy (SCSM). Methods Between June 2005 and June 2008, 17 patients with SCSM were treated with ASDDF. There were 10 males and 7 females with an average age of 58.8 years (range, 41-74 years) and an average disease duration of 9.7 months (range, 6-39 months). According to JapaneseOrthopaedic Association (JOA) score system, 2 patients were rated as extreme severe condition, 7 as severe, 7 as moderate, and 1 as mild. MRI images showed 42 affected cervical disc levels, including 26 disc levels with high-intensity intramedullary lesions on T2, 4 with low-intensity intramedullary lesions on T1, and 12 with significant cord compression but no signal change; according to Nagata classification scale, there were 5 abnormal segments at class I, 21 at class II, and 16 at class III. The rate of fusion, the Cobb angle, and the range of motion (ROM) of the cervical spine were measured preoperatively and postoperatively by the X-ray examinations. The improvement of the neurological function was evaluated by the JOA score. Results The average time of follow-up was 28.6 months (range, 24-58 months). After operation, dysphagia occurred in 2 cases (symptom rel ief after 1 month), hoarseness in 1 case (symptom rel ief after 3 months of methylcobalamin treatment), and degeneration of adjacent segments without symptom in 3 cases. The X-ray films showed the fusion rate of 100% at 12 months after operation without displacement, resorption or collapse of bone graft, and without breakage or loosening of plate and screw. The Cobb angles were (13.3 ± 10.4)° preoperatively, (15.8 ± 10.8)° immediately postoperatively, and (15.4 ± 11.4)° at last follow-up; the ROM of the cervical spine were (41.3 ± 17.4)° preoperatively and (23.8 ± 18.8)° at last follow-up; and the JOA scores were 8.2 ± 2.9 preoperatively, 13.7 ± 3.0 at 12 months postoperatively, and 13.9 ± 2.8 at last follow-up. All indexes showed significant differences between before operation and after operation (P lt; 0.05). The results of JOA scores were excellent in 8 cases, good in 6, fair in 2, and poor in 1 with an average improvement rate of 66.8% (range, 14%-88%) for the neurological function. Conclusion Adequate decompression, high rate of fusion, sol id mechanical stabil ity, improvement of total cervical lordosis,and the neurological function can be achieved through ASDDF for treatment of SCSM.