Association of Pars Defect Type with Clinical Outcome after Smiley Face Rod Methods for Terminal-Stage Spondylolysis

Abstract

Background:The smiley face rod method is an effective treatment for symptomatic terminal-stage spondylolysis. However, the risk factors for treatment failure are unknown. We investigated the association of pars defect type with the treatment outcomes of this method. Methods:We retrospectively examined data from 34 patients (18.0 ± 6.7 years) with terminal-stage spondylolysis who underwent surgery using the smiley face rod method.The mean follow-up period was 44.9 ± 21.4 months. The patients were divided into 2 groups: pars defect without bone atrophy or sclerosis (group A; 18 patients), and with bone atrophy and sclerosis (group B; 16 patients). We defined atrophy as a defect with a depression in the defect line that causes the defect to expand and the edge to become asymmetrical. We evaluated and compared the visual analog scale (VAS) score for back pain, bone union rate, and time to return to preinjury level athletics between the groups.Fisher exact and paired Student t tests were used to compare the variables between groups. The VAS score between the groups was compared using a 2-factor repeatedmeasures analysis of variance.Results: Within groups, the VAS score was significantly different over time (p < 0.001). The VAS scores between groups were not significantly different. Patients in Group A had a significantly higher bone union rate per pars at 6 months (group A, 65.7%; and group B, 37.5%, p = 0.028) and 24 months after surgery (group A, 97.1%; and group B, 75.0%, p = 0.011). All patients returned to their respective sports, and no significant differences were observed in the time to return to preinjury level athletics between the groups (p = 0.055). Conclusion:Pars sclerosis defects are associated with bone nonunion, but have little

Combined Transforaminal Lumbar Interbody Fusion and Smiley Face Rod Technique Using Dual-Headed Pedicle Screws for L4 Isthmic Spondylolisthesis and L5 Spondylolysis

“…Recent surgical techniques for lumbar spondylolysis with pseudarthrosis include the hook rod technique [ 4 ] or the SFR technique [ 2 ]. The beginning of history of the SFR technique was reported as the V-rod technique began by Gillet et al in 1999 [ 5 ].…”

“…Transforaminal lumbar interbody fusion (TLIF) is one of the main surgical techniques to treat isthmic lumbar spondylolisthesis with lower extremity pain [ 1 ]. Spondylolysis with pseudarthrosis may be treated surgically by repairing the spondylolysis using the smiley face rod (SFR) technique [ 2 ]. We report a case of 4th lumbar (L4) isthmic spondylolisthesis and 5th lumbar (L5) spondylolysis without slip, in which a combination of TLIF and SFR with a dual-headed pedicle screw was performed.…”