Pull-out of Upper Thoracic Pedicle Screws Can Cause Spinal Canal Encroachment in Growing Rod Treatment.

BACKGROUND: Proximal foundation failure is a common complication of growing rod (GR) treatment for early-onset scoliosis. Spinal canal encroachment due to pull-out of pedicle screw used as proximal foundation has been anecdotally reported in GR patients. The aim of this study is to report the prevalence of spinal canal encroachment of pedicle screws in GR treatment and determine risk factors using a single-center cohort. METHODS: Inclusion criteria were: (1) GR for early-onset scoliosis and (2) pull-out of at least 1 proximal anchor pedicle screw. Patients were divided into 2 groups according to the presence of medial screw migration. Medial migration of the screw was confirmed by computed tomography. The extracted data included demographic, clinical, and radiographic information. RESULTS: A total of 21 patients (of 96) met inclusion criteria (21.8%). None of the screws appeared malpositioned on early postoperative x-ray. Average follow-up until screw failure was 50.4 months (64 to 85 mo) and average number of lengthenings 8.1 (4 to 13). Computed tomography revealed canal encroachment in 11 patients (group 1), and no encroachment in 10 (group 2). There was no significant difference between groups for age, follow-up or number of lengthenings. At the time of screw pull-out, coronal plane deformity was increased compared with early postoperative x-ray in all; however, this increase was significantly higher in group 1 (45.7 vs. 35 degrees, P=0.002). Proximal junctional angle (PJA) was increased in both groups at the time of pull-out. While not statistically significant, PJA increased linearly in group 1 but spiked in group 2 at the time of pull-out. There was no neurological event preoperatively, intraoperatively or postoperatively. Failed screws were safely revised in either planned/unplanned surgeries. CONCLUSIONS: In patients with proximal anchor failure of GR, especially if there is increase of coronal deformity and/or PJA, possible spinal encroachment should be kept in mind. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Health-Related Quality of Life in Early-Onset Scoliosis Patients Treated Surgically: EOSQ Scores in Traditional Growing Rod Versus Magnetically Controlled Growing Rods.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To compare quality of life and caregiver burden in traditional growing rod (TGR) and magnetic controlled growing rods (MCGR) patients. SUMMARY OF BACKGROUND DATA: MCGR decrease surgical sessions associated with treatment of early onset scoliosis (EOS), hoping to minimize the burdens seen with repetitive invasive surgeries in TGR treatment. Although the clinical indications for these treatments have largely been agreed upon, there is a lack of understanding of their impact on patients' and families' quality of life. METHODS: Inclusion criteria: ≤10 years of age at index procedure, major curve ≥30°, no previous spine surgery, minimum 1-year postoperative follow-up. The previously validated 24-item early onset scoliosis questionnaire (EOSQ-24) was utilized to assess quality of life. Statistic methods were applied to compare domain scores between TGR and MCGR patients. RESULTS: Forty-four children with EOS were enrolled; 25 TGR and 19 MCGR. Groups were similar in sex and age at index surgery. Age at time of questionnaire and mean length of follow-up were significantly different; patients were older (14.0 vs. 8.8 yr) and had longer follow-up (101.3 vs. 34.3 mo) in TGR (P < 0.01). Deformity correction and complication rates were similar between groups. At the time of questionnaire, scores of economic burden and overall satisfaction in MCGR were significantly superior to those in TGR by univariate analysis. When controlled for duration of follow-up, some domain scores trended towards statistical significance, some remained stable, and others regressed to non-significance. CONCLUSION: Health related quality of life data reveal superior outcomes in overall satisfaction and financial burden domains in the MCGR group. However, the positive effects of MCGR decrease when controlled for length of follow up, indicating that the MCGR is not yet a magic fix-all, and that the TGR remains an option in the treatment of EOS. LEVEL OF EVIDENCE: 3.