| Objective To investigate the clinical technique, effects of decompression and interbody fusion by microendoscopic. The operation-related anatomical structures were studied to provide anatomical datas for the applications of clinic. Materials and methods From September 2012 to Octomber 2014,96 patients with degenerative lumbar instability syndrome underwent microendoscopie translamilar decompression and transforaminal fusion. All the patients presented with persistent low back pain accomplied by bilateral or unilateral numbness, pain, intermittent elauditieation and limitation of lumbar spine ROM. All patients had single segment instability on dynamic radiography, with the translational motion over 4mm or angular variation over 11°,patients with slippage over I degree were excluded. X-ray was performed at 2 weeks and every 3 months after the operation. The clinical short term outcome were assessed by Maenab criteria. Local operation-related anatomical landmarks and other anatomical structures of adult lumbar spine in 10 adult cadavers specimens was observed and measured. The anatomical landmarks mainly include 3 points:the highest point of lumbar zygapophysial joint(HP), the cross point of superior articular process and transverse process(TAP), and the bone fibrous foramen. We measures (1) the distance of HP-N, HP-PP, MD and HP-MD;(2) the distance of TAP-N, TAP-PP, TAP-MD;(3)the length and width of intertransverse ligament and bone fibrous foramen; respectively. Results (1) The operative time was 80-170 minutes (mean105±5 minutes); with the blood loss of 115-220ml (mean 157±18 ml). All the cases experienced surgery and were followed up for 6-20 months (mean 16 months). No complication was found in any case. (2) About 50% (48) of cases was rated excellent, 41.7%(40) good and 8.3%(8) fair according to the Macnab criteria 1 year after the surgery. (3) X-ray was used to assess the condition of vertebral fusion, ODI and VAS scores ware used to assess the curative effect. 35.4%(34) and 64.6% (62) of cases get vertebral fusion at the 6 and 9 months after surgery. The ODI and VAS scores show statistically significant improvements(p<0.01) before and after the surgery. (4)HP: ?The distance of HP-N was Ll/2:19.9±2.3, L2/3: 21.6±2.0, L3/4 :21.9± 2.3, L4/5:24.1±2.8; ?The distance of HP-PP were Ll/2:24.5±2.5, L2/3:25.5±3.2, L3/4:28.2±2.4, L4/5:28.1±3.0;③The height of MD and the distance of HP-MD were Ll/2:9.7±1.3, 0.8±20.0; L2/3:10.4±1.4, 1.1±2.2; L3/4 :10.7±2.1, 1.4±1.9; L4/5:11.2± 1.6,1.5±2.6. TAP: ①The distance of TAP-N were Ll/2:14.6+2.5, L2/3:11.2±1.7, L3/4:8.9 ±1.4, L4/5:8.0±2.5; ②The distance of TAP-PP were L1/2: 11.8±1.7, L2/3: 13.0±1.7, L3/4: 12.1±2.4, L4/5: 12.6±2.3; ?The distance of TAP-MD were Ll/2:4.2±0.9,L2/3:3.5 ±0.5, L3/4 :3.5 ± 0.7, L4/5: 0.9±2.3. Intertransverse ligament and bone fibrous foramen: The length of intertransverse ligament were L1/2: 21.9 ±2.2, L2/3:23.1±2.1, L3/4:22.6±1.9, L4/5:22.5±1.4,respectively;The length and width of bone fibrous foramen were Ll/2 :4.2 ± 1.0, 4.4±0.9, 4.0±0.7, 4.0±0.7; L2/3:5.0±0.8, 4.9±0.8, 3.8±0.2, 3.7±0.2; L3/4:5.0 ±0.8,4.9±0.8,3.9±0.2,3.9±0.3; L4/5:5.1±0.8,5.1±0.8,4.0±0.1,4.0±0.2, respectively. Conclusion (1)HP, TAP and bone fibrous foramen are useful anatomical landmarks in the lumbar foraminal region and can provide distance and distribution trends for the operation. Taking them as reference could help to improve safety successfully and reduce injury. (2)The operative approach of lumbar-foramina entry shows minimally invasive, higher safety and don’t affect the stability of adjacent spinal for degenerative lumbar instability syndrome involving L1-L5 of adults. (3) The technique and effect of decompression and interbody fusion using microendoscopic could provide a minimally invasive and satisfactory treatment result for degenerative lumbar instability syndrome involving L1-L5 of adults. |
