Minimally Invasive Versus Standard Surgery in Idiopathic Scoliosis Patients

A Comparative Study

Vishal Sarwahi, MD; Jesse M. Galina, BS; Sayyida Hasan, BS; Aaron Atlas, BS; Alexandre Ansorge, MD; Charlotte De Bodman, MD; Yungtai Lo, PhD; Terry D. Amaral, MD; Romain Dayer, MD


Spine. 2021;46(19):1326-1335. 

In This Article

Abstract and Introduction


Study Design: Retrospective review of prospective case–control study.

Objective: To compare minimally invasive scoliosis surgery (MIS) and posterior spinal fusion (PSF) in a large group of patients.

Summary of Background Data: MIS, has been shown to have benefits over standard PSF in adolescent idiopathic scoliosis (AIS).

Methods: Radiographic, clinical, and operative review of a multi-institutional prospective database from 2013 to 2018. MIS patients with minimum 2-year XR follow up were compared with open PSF technique patients.

Results: Four hundred eighty five patients were included; 192 MIS and 293 PSF. Preoperative Cobb (P = 0.231) and kyphosis were similar (P = 0.501). Cobb correction was comparable (P = 0.46), however percent improvement in thoracic kyphosis was significantly higher in MIS (P < 0.001). MIS had significantly lower blood loss (P < 0.001), transfusions (P < 0.001), fixation points (P < 0.001), opioid consumption (P = 0.001), and hospital stay (P < 0.001). Operative time was shorter (P = 0.001) and 30-day complications rate was similar (P = 0.81).

Conclusion: This is the largest study comparing the surgical outcomes of MIS and PSF. MIS patients benefit from increased kyphosis, fewer transfusion, lower opioid consumption, and shorter hospital stay with similar Cobb correction. Increased postoperative kyphosis is likely from muscle sparing dissection in MIS.

Level of Evidence: 3


Posterior spine fusion (PSF) for adolescent idiopathic scoliosis (AIS) involves extensive muscle dissection,[1] which causes substantial blood loss (EBL) leading to 20% to 30% risk of blood transfusions[2–4] and disrupts midline structures implicated in proximal junctional kyphosis.[5] It also causes substantial pain, increasing narcotic consumption, prolonging hospital stay, and recovery.[6] Reames et al,[7] reviewed the Scoliosis Research Society (SRS) 2004 to 2007 morbidity and mortality database and found 6.3% complication rate in AIS. Vigneswaran et al[8] reviewed the 1997 to 2012 Kids' Inpatient Database (KID) and found PSF complication rates increased from 14.5% in 1997 to 22% in 2012. Lam et al[9] using the 2009 KID data, found 25.1% transfusion rate. Yoshihara and Yoneoka[10] reviewed the 2000 to 2009 Nationwide Inpatient Sample database and found 30.4% of idiopathic patients received transfusion. Mange et al[11] reviewed 402 idiopathic scoliosis PSF patients between 2015 and 2017 and reported 18.2% transfusion rate. Eisler et al[12] reviewed 6626 patients from the 2016 to 2018 National Surgical Quality Improvement Program Pediatric (NSQIP-P) database, where 5434 (81%) received antifibrinolytics and 1533 (23%) received blood transfusion. Further analysis of 1192 propensity score matched pairs showed no significant transfusion reduction despite antifibrinolytics. Negative effects of transfusions in AIS have been reported. Ho et al[13] reported transfusions were significant risk factors for delayed infections. Carreon et al,[4] reported 15.4% complications in AIS with increased EBL as risk factor for non-neurologic complications. Thus, minimizing blood loss and transfusion is a desired goal.

Minimally invasive surgery (MIS) allows soft tissue preservation, decreased EBL, transfusions, and hospital stay. Feasibility of MIS in AIS was described by Sarwahi et al[14] in 2011. Separately, Sarwahi et al[15] reported significantly lower transfusions, levels fused, and fixation points with MIS. Miyanji et al[16] found MIS had significantly less EBL, transfusions, and hospital stay. Urbanski et al[17] compared Lenke 5C curves treated with MIS and open procedure. MIS took longer, had less EBL, shorter hospital stay, and lower opioid requirements.

MIS is technically demanding and takes longer than PSF. Sarwahi et al,[15] found it took 2-hours longer, and Miyanji et al[16] reported 129 minutes longer. However, literature on MIS is scarce. Two recent studies have reported on larger samples. De Bodman et al[18] evaluated 70 AIS patients and found mean 69% Cobb correction, operative time 337.1 minutes, EBL 345.7 mL and 4.6 day stay. Eight patients had complications, three perioperative and five delayed. Yang et al[19] evaluated 84 AIS patients and found mean 68.9% correction, operative time 312.8 minutes, EBL 846.6 mL, and 8.5 day stay.

Despite similar correction, decreased EBL and shorter hospital stay; prolonged surgical and anesthesia time are shortcomings of MIS. Decreased pain is not well documented and concerns about implant complications, nonunion and potential biologic use exist. Thus, it is important to study larger AIS patient populations undergoing MIS in multi-institutional settings, to analyze reported advantages, shortcomings, and ascertain its role in AIS.