RESUMO
Objective:To investigate reversal of vertebral wedging and to evaluate the contribution of adding satellite rods to correction maintenance in patients with adolescent Scheuermann kyphosis (SK) after posterior-only instrumented correction.Methods:A retrospective cohort study with SK was performed. From January 2009 to December 2018, a total of 26 SK patients (21 males and 5 females) who received posterior instrumented correction surgery at the age of 13–16 years were included. The mean age was 14.5±0.9 years. Risser sign was level 1 in 5 patients, level 2 in 10 patients and level 3 in 11 patients. Patients receiving placement with a standard 2-RC construct were composed in the 2-RC group, and those with enhanced instrumentation with satellite rods adding to 2-RC via duet screws were assigned to the S-RC group. The anterior vertebral body height (AVBH), posterior vertebral body height (PVBH), global kyphosis (GK), disc wedging angle (DWA), vertebral wedging angle (VWA) and Scoliosis Research Society questionnaires-22 (SRS-22) were collected preoperatively, immediately postoperatively, and at the latest follow-up. Further, these outcomes were compared between the two groups.Results:The average follow-up durations for the S-RC and 2-RC groups were 3.1±1.0 and 2.9±1.1 years ( t=0.04, P=0.837), respectively. Remarkable postoperative correction of GK was observed in S-RC group and 2-RC group without significant difference (51.1%±5.1% vs. 46.7%±5.8%, t=1.74, P=0.099). The correction loss of S-RC group was significantly less than that at 2-RC group during follow-up (0.6°±0.3° vs. 1.8°±0.8°, t=-6.52, P<0.001). The ratio between AVBH and PVBH of deformed vertebrae notably increased in S-RC group and 2-RC group from post-operation to the latest follow-up ( P<0.05). Compared with the 2-RC group, the S-RC group had significantly greater increase in AVBH/PVBH ratio during follow-up (32.6%±8.5% vs. 22.5%±13.4%, t=2.31, P=0.030). The two groups had similar preoperative and postoperative SRS-22 questionnaire scores for all domains ( P>0.05). Conclusion:The AVBH of deformed vertebrae could be increased after posterior correction in SK patients. Compared with the traditional two-rod construct, satellite rods construction could be more effective which could achieve greater vertebral remodeling and less correction loss.
RESUMO
Objective:To investigate the association of the cross-sectional area of lumbar paraspinal muscle with the spino-pelvic profile based on Roussouly classification.Methods:From January 2019 to December 2019, 102 patients with lumbar disc herniation were collected, the index level included L 2, 3 in 3 cases(2.9%), L 3, 4 in 14 cases(13.7%), L 4,5 in 58 cases (56.9%), and L 5S 1 in 27 cases (23.5%). According to Roussouly classification, there were 29 cases of type I (28.4%), aged 57.0±11.7 years old (range 43 to 72 years old), 31 of type II (30.4%), aged 56.9±10.3 years old (range 40 to 70 years old), 28 of type III (27.5%), aged 53.5±12.9 years old (range 42 to 70 years old), and 14 of type IV (13.7%), aged 59.7±9.5 years old (range 51 to 70 years old). The clinical status of the patients were evaluated with the MOS 36-item short-form health survey (SF-36), Oswestry disability index (ODI) and visual analog scale (VAS). Select all patients with L 1, 2, L 2, 3, L 3, 4, L 4, 5 and L 5S 1 disc level axial MRI images, to measure the cross-sectional area (CSA) of paraspinal muscles (back extensor muscle and psoas muscle) and the CSA of intervertebral disc at each disc level, and calculate the relative cross-sectional area (RCSA: the ratio of the CSA of muscles to that of the disc at the same level). One-way ANOVA was used to test the RCSA of the paraspinal muscles of the four groups, and then LSD- t test was used for pair wise comparisons to compare the RCSA of the paraspinal muscles in each group. Results:There was no significant difference in age ( F=1.067, P=0.367), female/male sex ratio ( χ2=2.412, P=0.491) and body mass index ( F=0.326, P=0.481). Roussouly type I group showed lower SF-36 score in both SF-36 PCS (31.5±6.5, F=3.207, P=0.047) and SF-36 MCS (33.9±5.7, F=3.409, P=0.031) compared with the other three types. In contrast, there were no significant differences in VAS Back Pain ( F=0.140, P>0.05), VAS leg pain ( F=0.622, P>0.05). and ODI scores ( F=1.075, P>0.05) among the types. At each level from L 1, 2 to L 5S 1, the RCSA of psoas muscle in Roussouly type IV (19.18±6.98, 35.36±10.37, 41.25±14.35, 61.58±12.03, 59.29±11.73) was significantly lower than that in patients with any other Roussouly type ( P<0.05), while no significant difference in the psoas RCSA among type I, type II and type III curves ( P>0.05). With regards to back extensor muscle, the RCSAs of back extensor muscle in Roussouly types I (135.32±19.86, 138.53±22.92, 125.06±21.44, 122.40±19.69, 110.87±18.08) and II (131.30±18.68, 136.39±24.87, 122.61±22.52, 121.10±20.47, 107.46±18.29) were significantly lower than those in Roussouly type III and IV at each level ( P<0.05), yet no significant difference between type I and II or between type III and IV. The ratio between the RCSA of back extensor muscle and psoas muscle in four types increased gradually from L 1, 2 to L 5S 1, with that being higher in type II (0.20±0.07, 0.33±0.09, 0.40±0.13, 0.58±0.11, 0.65±0.08) and lower in type IV (0.13±0.05, 0.24±0.07, 0.31±0.10, 0.47±0.10, 0.52±0.11). Conclusion:RCSA of paraspinal muscles varied among Roussouly types, suggesting a significant association between paraspinal muscles and the sagittal spino-pelvic alignment. Sagittal spino-pelvic alignment may be involved in the degeneration of paraspinal muscles.