Seven Years on the Treadmill: A Glimpse Into ASLS Outcomes

If you ever needed proof that spine surgery can turn your patients into more resilient versions of themselves — at least on a treadmill — a long-term Adult Symptomatic Lumbar Scoliosis (ASLS) dataset delivers it with the subtlety of a patient bringing you 14 years of outside imaging: it’s undeniable, a little messy, and fascinating.

Study Design

A prospective longitudinal cohort — the research equivalent of keeping your patients on a clinical leash for nearly a decade. The study’s objective was to see what happened to Functional Treadmill Test (FTT) performance more than five years after ASLS patients picked their path: scalpel or “let’s-see-how-this-goes” conservative care.

The Two-Year Teaser

At two years, operative (Op) patients actually walked longer and stronger, while the nonoperative (NonOp) group slowed down like a treadmill at the end of its warranty. Both groups felt better, but the Op group had bigger wins.

So, the question became: Does the magic last?

Methods: Who survived to tell the tale?

Out of 272 survivors in the original cohort, 168 agreed to hop back on the treadmill at roughly 7.5 years post-intervention.

• Op: 115
• NonOp: 53

FTT metrics included:

• Maximum speed (i.e., how brave they felt cranking the treadmill up)
• Time to onset of symptoms (the moment the back whispers “remember me?”)
• Time and distance ambulated
• Pre- and post-test back/leg pain

Everything you love about patient-reported outcomes — except this time your patients actually had to move.

Results: Aging Happens, But Surgery Still Wins

Between the two-year mark and the final FTT, both groups slowed down. Welcome to aging.

But — and this is a big but — the NonOp group declined more. Their speed, walking time, and symptom onset dropped faster than you can say “maybe we should’ve operated.”

Op patients started with worse post-FTT pain at baseline but improved dramatically at two years and kept those gains through year seven. NonOp patients also improved — but not nearly as much.

Patients with ≥2 revisions didn’t fare as well. Translation: One revision is acceptable; two is a warning; three means the treadmill test is probably the least of their problems.

Surgery Still Plays the Long Game

Seven years later, surgically treated ASLS patients still show better FTT performance than their NonOp counterparts. Yes, everyone slowed down a bit — we’re all marching toward entropy — but the surgical advantage held up.

And revisions matter: the more times you go back in, the less treadmill glory your patient achieves.

Origin Study Title: Differences in Functional Treadmill Tests in Patients With Adult Symptomatic Lumbar Scoliosis Treated Operatively and Nonoperatively at a Minimum Five-year Follow-up

Authors: Carreon, Leah Y. M.D., MSc; Glassman, Steven D. M.D.; Smith, Justin S. M.D., Ph.D.; Yanik, Elizabeth L. Ph.D., ScM; Baldus, Christine RN, MHS; Kelly, Michael P. M.D., MSc; Bridwell, Keith H. M.D.