Minimally Invasive Surgery in Patients with Adolescent Idiopathic Scoliosis: Is it Better than the Standard Approach? A Two Year Follow-Up Study.

STUDY DESIGN: This is a retrospective controlled study.

OBJECTIVE: To compare the safety and efficacy of a minimally invasive approach (MIS) for the surgical management of adolescent idiopathic scoliosis (AIS) to the standard open posterior approach (PSF).

SUMMARY OF BACKGROUND DATA: MIS approaches offer the potential to reduce soft-tissue trauma, intraoperative blood loss, and surgical site infection. Thus far, MIS has been successfully utilized for the surgical correction of multilevel spine pathology in adults. It is not yet known if these results can be replicated in the surgical management of AIS.

METHODS: Seven MIS patients were compared to 15 PSF patients using minimum two-year follow-up data. Parameters studied included preoperative patient and deformity characteristics, perioperative parameters, extent of deformity correction, and complications. Data were compared using Mann-Whitney tests for continuous variables and Fisher's exact tests for categorical variables.

RESULTS: The MIS and PSF groups were similar for all preoperative characteristics collected (P>0.05). MIS patients had fewer fixation points (P=0.015), but a longer median operative time (P=0.011). There was no significant difference in estimated blood loss (EBL) (P=0.051), EBL/fixation point (P=0.204), or amount of fluids administered (P=0.888). Postoperative recovery did not differ between the two groups in number of ICU days (P=0.362), length of hospital stay (P=0.472), time to mobilization (P=1.00), VAS pain scores (P=0.698), or PCA (P=1.00). The MIS technique had similar deformity correction, screw placement accuracy, and fusion status when compared to the PSF group.

CONCLUSION: The short-term advantages seen in MIS for adult scoliosis were not as obvious in our series. Despite our findings of similar deformity correction and adequate fusion, concerns regarding quality of fusion, learning curve, and instrumentation persist. MIS surgery is an innovative treatment for AIS that is technically feasible; however, its advantages in the treatment of AIS are currently difficult to define.