Adding satellite rods to standard two-rod construct for promoting postoperative vertebral remodeling in scheuermann kyphosis / 中华骨科杂志

ABSTRACT

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.