Objective To analyze the influence of Wiltse approach and conventional transmuscular approach on the mul?tifidus muscle by imageology, histology and electrophysiology assessment following short?segment pedicle fixation on thoracolum?bar fractures. Methods 76 patients with thoracolumbar fractures without neurological deficits who had undergone short?segment pedicle fixation between June 2010 and August 2012. Wiltse approach 36 cases, conventional transmuscular approach 40 cases. The perioperative parameters, Visual Analogue Scale scores (VAS), and radiologic parameters, esp the imageology, histology and electrophysiology changes of multifidus muscle were compared. Results 20 cases were fellowed up over 1 year in the Wiltse ap?proach group (20/36, 56%). 25 cases were fellowed up over 1 year in the conventional transmuscular approach group (25/40, 62.5%). No significant differences were found in terms of gender, age, fracture type, injured segment and follow?up period. Till the last follow?up, all patients with vertebral fractures were healed. No loosening or breaking of internal fixation was observed. Com?pared to the conventional transmuscular approach, the Wiltse approach was significantly advantageous in terms of operation time, the amount of bleeding, hospital stays and VAS scores after the surgery but the length of incision, besides, the Wiltse approach group had less incidence of multifidus atrophy and less fatty infiltration, and in conventional transmuscular approach group electro?myography demonstrated that the multifidus muscles median frequency values and average amplitude value were significantly low?er than Wiltse approach group. Conclusion The Wiltse approach for thoracolumbar fractures, retaining the posterior ligament complex, is an effective and minimally invasive treatment, with less trauma, less bleeding, less operation time, the advantages of re?liable clinical results. Especially less incidence of multifidus atrophy and less fatty infiltration.

Objective:To compare the efficacy of oblique lumbar interbody fusion (OLIF) and minimally invasive interbody fusion (MI-TLIF) for degenerative lumbar spondylolisthesis.Methods:Data of 40 patients with I-II degree single level degenerative lumbar spondylolisthesis from January 2018 to December 2018 were retrospectively analyzed. According to the operation procedure, they were divided into two groups: OLIF group and MI-TLIF group, and each group had 20 patients. There were 15 males and 5 females in the OLIF group, aged 50.3±8.8 years; and there were 13 males and 7 females in the MI-TLIF group, aged 51.7±8.7 years. According to the Meyerding's grade system, there were 16 patients of type I in the OLIF group and 15 cases in the MI-TLIF group; and there were 4 patients of type II in the OLIF group and 5 cases in the MI-TLIF group. The operation time, intra-operative hemorrhage, postoperative drainage, recessive blood loss and albumin loss were recorded. The CRP and ESR on the third day after operation, the VAS score and ODI score before and after operation were recorded. The lumbar lordosis (LL), fused segmental lordosis (FSL) and disc height (DH) before and after operation were recorded. The time of getting out of bed and walking and the hospital stay were recorded. Paired t-test was used to analyze the data.Results:Forty patients successfully underwent the operation. The operation time of OLIF group was 96±20 min, with intraoperative blood loss of 61±32 ml and postoperative drainage volume of 18±8 ml. The operation time of MI-TLIF group was 132±26 min, with intraoperative blood loss of 262±102 ml and postoperative drainage volume of 95±42 ml; and there was statistical difference between the two groups ( t=4.901, 8.404, 8.064; P< 0.001). On the third day after operation, the occult blood loss was 139±47 ml in the OLIF group and 486±192 ml in the MI-TLIF group; the albumin loss was 4.2±1.9 g/L in the OLIF group and 10.2±3.9 g/L in the MI-TLIF group; CRP was 34±11 mg/L in the OLIF group and 106±39 mg/L in the MI-TLIF group; ESR was 41±15 mm/1 h in the OLIF group and 71±24 mm/1 h in the MI-TLIF group, and there all were statistical differences between the two groups ( t=7.838, 6.184, 7.983, 4.675; P< 0.001). The VAS scores were 2.2±1.5, 1.8±1.3 and ODI scores were 14%±11%, 59%±17%, respectively. There was no significant difference between the two groups. The LL were 33.41°±9.25°, 32.07°±9.54°, FSL were 11.59°±5.09°, 10.61°±4.56° and DH were 10.35±2.30 mm, 10.85±1.85 mm, respectively. There was no significant difference between the two groups. The follow-up time was 13.5±2.3 months in the OLIF group and 14.1±2.8 months in the MI-TLIF group. Three patients in the MI-TLIF group had radiation pain in the lower extremity on the third day after operation, which relieved after NSAID drugs and mannitol treatment. In the group of OLIF, the skin temperature of the left lower extremity increased in 1 case on the first day after operation, in which sympathetic chain injury was considered, and the patient recovered after 2.5 months; in the group of OLIF, the numbness in the front of the left thigh and the weakness of flexion of the hip was found in 3 cases, in which the edema or injury of the psoas major muscle was considered. Conclusion:Compared with MI-TLIF in the treatment of I, II degree single segment degenerative lumbar spondylolisthesis, OLIF has the advantages of shorter operation time, less intraoperative and postoperative blood loss, lower inflammation index, earlier time to get out of bed and shorter hospital stay. However, the outcomes of the two surgeries were similar.