Early and Late Reoperation Rates and Etiologies are Similar Between cMIS and HYB Techniques for ASD Correction

Presented at SMISS Annual Forum 2016
By Robert Eastlack MD
With

Disclosures: Robert Eastlack MD A; Nuvasive, Research Support in Unrestricted Grant from Trinity Orthopedics. B; Aesculap, Alphatec Spine, Depuy, DiFusion, DJ Orthopaedics, Invuity, K2M, Nuvasive, Seaspine, Stryker, Titan. C; Eli Li

Introduction

Reoperation after correction of adult spinal deformity (ADS) results in additional cost and morbidity. The rates and etiologies of reoperations may be impacted by the method of ASD correction. We aimed to characterize the reoperation rates and etiologies when performing ASD surgery with cMIS and HYB techniques. 

Aims/Objectives

To determine the rates and reasons for reoperations will between cMIS and HYB techniques for
ASD correction. 

Methods

A multicenter database was queried. Inclusion criteria for the database included age ≥18 years, and one of the following: CC>20, SVA>5cm, PT>20, PI-LL>10. Patients with either circumferential MIS (cMIS) or hybrid (HYB) surgery, and ≥3 spinal levels treated with 2-year minimum follow-up were included for analysis.

Results

420 patients met inclusion criteria for the database. Of those 165 had complete 2-year data, and a total of 133 met inclusion for this study (65 HYB and 68 cMIS). Junctional failure (15.4%) was the most common reason for reoperation in the HYB group, while fixation failure was the most common reason in the cMIS group (8.8%). There was a higher incidence of PJF than DJF within HYB (12.3% vs. 3.1%), but no significant differences in PJF or DJF rates when compared to cMIS. There were no other differences between cMIS and HYB when analyzing reasons for reoperation. Early (<30 days) reoperations were less common in both groups (cMIS=1.5%; HYB=6.1%) than late (>30 days) reoperations (cMIS=26.5%; HYB=27.7%), but rates were similar between groups. 

Conclusions

ASD correction with CMIS and HYB techniques result in overall reoperation rates of 27.9% and 33.8%, respectively, at minimum 2-year follow-up. Junctional failures are more common after HYB approaches, while pseudarthrosis/fixation failures happen more often with cMIS techniques. Early reoperations were less common than later returns to the OR in both groups. These reoperation rates compare favorably with open ASD surgery, although the reasons for failure may differ. Further study will be done to evaluate the specific differences between reoperation etiologies when comparing open vs. MIS ASD correction.