Correlation of Lower Instrumented Vertebra With Spinal Mobility and Health-related Quality of Life After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

Abstract

Study Design: This is a retrospective single-center and single-surgeon study. Objective: We investigated the correlation between lower instrumented vertebra (LIV) and spinal mobility 2 years after posterior spinal fusion with pedicle screws for adolescent idiopathic scoliosis (AIS) for optimal LIV selection. Summary of Background: Spinal motion can become limited in scoliosis patients who undergo posterior spinal fusion. However, few reports exist on spinal mobility after posterior spinal fusion for AIS and the relationship between the LIV and mobility is unknown. We hypothesize that mobility limitation increases as the LIV is moved inferiorly. Data: Of 72 consecutive patients who received posterior spinal fusion using pedicle screws for AIS between October 2009 and August 2015, 66 patients (5 male and 61 female, mean age: 14.9 y) were enrolled. Materials and Methods: In total, 66 patients were retrospectively reviewed after stratification according to LIV level. Follow-up rate was 91.7%. Patients were examined for the fingertip-to-floor distance (FFD) before and 2 years after surgery. FFD was measured from the tips of the middle fingers to the floor with the barefoot subject bent maximally forward and the feet together and knees straight. Clinical outcome was assessed using Scoliosis Research Society-22 patient questionnaire (SRS-22r) scores and a visual analog scale for low back pain before and at 2 years postoperatively. Results: The median number of fused vertebrae was 9 (range: 4–15). The LIV was T11–12 in 15 patients, L1 in 11 patients, L2 in 10 patients, and L3 in 30 patients. The median decrease in FFD according to LIV at 2 years after surgery was T11–12: 0 cm, L1: 0 cm, L2: 5.5 cm, and L3: 10 cm. Thus, limited FFD became significantly more severe as the LIV was moved downwards (P<0.01). There were no significant correlations between limited FFD and SRS-22r or pain visual analog scale scores at 2 years postoperatively. Conclusions: FFD became significantly more restricted as the LIV was moved inferiorly but clinical results appeared unaffected by limited FFD.

Effect of Instrumentation Level on Mental Health Subscale of Scoliosis Research Society Outcomes Questionnaire in Adolescent Idiopathic Scoliosis

“…In our study in POY2, there was no difference between groups in terms of pain, function and satisfaction subscales in addition to self-image score as indicated in literature [ 4 ]. In other words, these patients agreed that the treatment that should be applied to them was applied.…”

“…However, in the patient group with LIV L5, MH scores were significantly lower than in other groups. Although the most common complaint of patients who underwent surgery for Scoliosis is cosmetic reasons [ 4 ], self-image scores of the Lenke type 5 patients improve postoperatively in all groups; therefore, with the improvement of body images of patients, they start to worry about their mobility instead of cosmesis. AIS patients have been shown to be unhappier with their lives with higher depression [ 22 ].…”

“…In the selective fusion of a structural thoracic curve, the lumbar curve is not fused to preserve postoperative mobility and flexibility despite the possibility of providing more correction. On the other hand, the fusion of the structural lumbar curve in lumbar scoliosis will decrease postoperative flexibility and mobility [ 4 ].…”

“…The lumbar spine is more mobile than the thoracic spine due to different orientations of facet joints and not being fixed with ribs [ 4 ]. Ordinary issues that a person with a healthy spine can easily apply in daily life such as tying shoelaces, leaning forward, picking up a falling object from the ground can be problematic in some scoliosis patients.…”

Global Spine Range of Motion in Patients With Adolescent Idiopathic Scoliosis Before and After Corrective Surgery

“…Uehara et al [ 14 ] conducted a similar study comparing LIV on spine motion. They focused specifically on changes in sagittal motion using the fingertip-to-floor distance (FFD) test preoperatively and at two-year follow-up.…”