Who should have surgery for spinal stenosis?: Treatment effect predictors in SPORT

Brief review

*Title: Who should have surgery for spinal stenosis?: Treatment effect predictors in SPORT.

누가 척추 협착증을 위한 수술을 받아야 하는가?

: SPORT(Spine Patient Outcome Research Trial)에서의 치료효과의 예측변수

*Author: Adam Pearson, Jon Lurie, Tor Tosteson, Wenyan Zhao, William Abdu, James N. Weinstein

*Bibliography: Spine(Phila Pa 1976). 2012 Oct 1;37(21):1791-802.

STUDY DESIGN: Combined prospective randomized controlled trial and observational cohort study of spinal stenosis (SpS) with an as-treated analysis.

OBJECTIVE: To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for SpS using subgroup analysis.

SUMMARY OF BACKGROUND DATA: The Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for SpS at the group level. However, individual characteristics may affect TE. No previous studies have evaluated TE modifiers in SpS.

METHODS:

▶Study design: Spinal stenosis patients were treated with either surgery (n = 419) or nonoperative care (n = 235) and were analyzed according to treatment received.

▶Patient Population

-Inclusion criteria: had neurogenic claudication or radicular pain for at least 12 weeks, a confirmatory cross-sectional imaging study demonstrating stenosis at 1 or more levels.

-Exclusion criteria: cauda equina syndrome, malignancy, significant deformity, previous back surgery, instability on flexion-extension radiographs, and other established contraindications to elective surgery.

▶Statistical Considerations: The TE of surgery was defined as:

TE (Treatment Effect)= change in ODI (surgery) – change in ODI (nonoperative)

RESULTS:

-All analyzed subgroups improved significantly more with surgery than with nonoperative treatment 

(P < 0.05).

-Details of the below were associated with greater TE.

baseline ODI ≤ 56 (TE -15.0 vs. -4.4, ODI > 56, P < 0.001),

not smoking (TE -11.7 vs. -1.6 smokers, P < 0.001),

neuroforaminal stenosis (TE -14.2 vs. -8.7 no neuroforaminal stenosis, P = 0.002),

predominant leg pain (TE -11.5 vs. -7.3 predominant back pain, P = 0.035),

not lifting at work (TE -12.5 vs. -0.5 lifting at work, P = 0.017),

the presence of a neurological deficit (TE -13.3 vs. -7.2 no neurological deficit, P < 0.001).

CONCLUSION:

-Patients improved more with surgery than with nonoperative treatment, regardless of other specific characteristics.

-However, TE varied significantly across certain subgroups, and these data can be used to individualize shared decision making discussions about likely outcomes.

Key Points

●Other than smokers, all patient subgroups improved more with surgery than with nonoperative treatment.

●Baseline ODI score less than 56, not smoking, neuroforaminal stenosis, predominant leg pain, not lifting at work, and baseline neurological deficit predicted a greater TE of surgery.

●Smoking cessation should be considered before surgery for SpS.

●These data can be used to help to individualize shared decision-making discussions about likely outcomes after surgical or nonoperative treatment for SpS.