General Session: MIS-2
Presented by: A. Tohmeh - View Audio/Video Presentation (Members Only)
A. Tohmeh(1), A. Proctor(1), A. Khawaja(1)
(1) Northwest Orthopaedic Specialists, Spokane, WA, United States
Introduction: Hybrid approaches for deformity correction have been described where a minimally invasive (MIS) anterior (typically mini-open lateral interbody fusion (LLIF)) approach is used followed by standard open exposure for posterior osteotomy and instrumented fusion. While effective, this does not embody a true modern minimally invasive solution to deformity correction, as the vast majority of the morbidity is inherent to the open posterior approach. An MIS hybrid deformity technique has been introduced that utilizes MIS anterior interbody fusion followed by percutaneous lumbar fixation and open thoracic fixation for treatment of more advanced deformity with significant minimization of morbidity. The object of this study is to present a surgical technique for minimally invasive hybrid deformity correction as well as a series of patients treated with this technique.
Methods: A prospective, IRB-approved, single-arm clinical and radiographic study was undertaken. 23 consecutive patients were treated for deformity correction with an MIS anterior interbody fusion for adult deformity with an MIS Hybrid posterior approach (as previously described). Interbody fusion was performed in all cases with an average of 4 levels of LLIF (range 2-5) and 10 patients had an L5-S1 MIS TLIF. Posterior fixation was placed at an average of 7 levels. Facet releases were performed in 87% of cases and 10 (43%) patients had an anterior longitudinal ligament release for anterior column reconstruction (ACR). Mid-term clinical and radiographic results were evaluated through an average of 13 months (range 3 - 27).
Results: Mean total procedure (anterior and posterior approaches) blood loss, operative time, and length of stay (including staging time) was 336 minutes, 877 mL, and 8 days, respectively. From preoperative to last follow up, mean coronal cobb angle improved 61% (39.9° to 15.4°), lumbar lordosis (LL) increased 23% (34.7° to 42.6°), pelvic tilt decreased from 26.9° to 22°, and pelvic incidence (PI) - LL proportionality improved 43% from 19.1° to 10.8°. T1SPI remained constant (-3.3° to -0.8°). Over the same time points, low back and leg pain improved from 7.6 to 2.9 and 4.2 to 2.0, respectively. Disability (ODI) improved from 48.2 to 21.6 and quality of life (SF-36 PCS) improved from 49.4 to 59.8. At last follow up, 91% of patients were both either very or somewhat satisfied with their outcome and would have undergone the procedure again had their outcome been known in advance.
Conclusions: These initial results suggest that a hybrid MIS approach is a reasonable approach in the treatment of more advanced deformity through an MIS anterior interbody, MIS posterior lumbar, and open posterior thoracic approaches with select facet release and osteotomies and ACR. Major complications were few, clinical outcomes were excellent at mid-term time points, and radiographic results were promising.