Surgeon Experience Does Not Change Rate of Perioperative Surgical Complication in Rib-Based Distraction Surgery for Early-Onset Scoliosis

Rib-to-spine and rib-to-pelvis magnetically controlled growing rods: does the law of diminishing returns still apply?

PURPOSE

The Law Of Diminishing Returns (LODR) has been demonstrated for traditional growing rods, but there is conflicting data regarding the lengthening behavior of Magnetically Controlled Growing Rods (MCGR). This study examines a cohort of patients with early-onset scoliosis (EOS) with rib-to-spine or rib-to-pelvis-based MCGR implants to determine if they demonstrate the LODR, and if there are differences in lengthening behaviors between the groups.

METHODS

A prospectively collected multicenter EOS registry was queried for patients with MCGR with a minimum 2-year follow-up. Patients with rib-based proximal anchors and either spine- or pelvis-based distal anchors were included. Patients with non-MCGR, unilateral constructs, < 3 lengthenings, or missing > 25% datapoints were excluded. Patients were further divided into Primary-MCGR (pMCGR) and Secondary-MCGR (sMCGR).

RESULTS

43 rib-to-spine and 31 rib-to-pelvis MCGR patients were included. There was no difference in pre-implantation, post-implantation and pre-definitive procedure T1-T12 height, T1-S1 height, and major Cobb angles between the groups (p > 0.05). Sub-analysis was performed on 41 pMCGR and 19 sMCGR rib-to-spine patients, and 31 pMCGR and 17 sMCGR rib-to-pelvis patients. There is a decrease in rod lengthenings achieved at subsequent lengthenings for each group: rib-to-spine pMCGR (rho = 0.979, p < 0.001), rib-to-spine sMCGR (rho = 0.855, p = 0.002), rib-to-pelvis pMCGR (rho = 0.568, p = 0.027), and rib-to-pelvis sMCGR (rho = 0.817, p = 0.007). Rib-to-spine pMCGR had diminished lengthening over time for idiopathic, neuromuscular, and syndromic patients (p < 0.05), with no differences between the groups (p > 0.05). Rib-to-pelvis pMCGR neuromuscular patients had decreased lengthening over time (p = 0.01), but syndromic patients had preserved lengthening over time (p = 0.65).

CONCLUSION

Rib-to-spine and rib-to-pelvis pMCGR and sMCGR demonstrate diminished ability to lengthen over subsequent lengthenings.

The Effect of Surgeon Experience on Outcomes Following Growth Friendly Instrumentation for Early Onset Scoliosis

BACKGROUND

The purpose of this study was to utilize a multicenter, multisurgeon cohort to assess the effect of surgeon experience on outcomes of growth friendly instrumentation (GFI) in early onset scoliosis (EOS). We hypothesized that unplanned return to the operating room (UPROR), estimated blood loss (EBL), and surgical time would be greater amongst early career surgeons (ECSs) when compared with advanced career surgeons (ACSs).

METHODS

An international pediatric spine database was queried for patients ages 2 to 10 years treated by posterior distraction-based GFI with at least of 2-year follow up. Two groups were created for analysis based on surgeon experience: ECSs (with ≤10 y of experience) and ACSs (with >10 y of experience). The primary outcome was UPROR. Additional outcomes included: operating room time, EBL, neurological deficits, infection rate, hardware failure, and the Early Onset Scoliosis Questionnaire (EOSQ-24). Subgroup analysis was performed for further assessment based on procedure type, superior anchor type, etiology, and curve severity.

RESULTS

A total of 960 patients met inclusion criteria including 243 (25.3%) treated by ECS. Etiology, sex, superior anchor, and EOSQ-24 scores were similar between groups (P>0.05). There were no clinically significant differences in patient age or preoperative major coronal curve. UPROR (35.8% vs. 32.7%, P=0.532), infection (17.0% vs. 15.6%, P=0.698), operating room time (235 vs. 231 min, P=0.755), and EBL (151 vs. 155 mL, P=0.833) were comparable between ECS and ACS groups. The frequency of having at least 1 complication was relatively high but comparable among groups (60.7% vs. 62.6%, P=0.709). EOSQ-24 subdomain scores were similar between groups at 2-year follow-up (P>0.05). Subgroup analysis revealed that ECS had increased surgical time compared with ACS in severe curves >90 degrees (270 vs. 229 min, P=0.05).

CONCLUSIONS

This study represents the first multicenter assessment of surgeon experience on outcomes in EOS. Overall, surgeon experience did not significantly influence UPROR, complication rates, EBL, or surgical time associated with GFI in this cohort of EOS patients.

LEVEL OF EVIDENCE

Level III.