Spine Align

Start with your alignment targets.

Define the permitted procedures, fusion levels, and instrumentation. Explore candidate surgical plans generated by a genetic algorithm.

Patient parameters

Enter preoperative sagittal parameters or load an example case. Set alignment targets and surgical constraints, then select Search candidate plans to run the genetic algorithm.

Spinopelvic (required)

PI * LL * T4PA * L1PA *

Spinopelvic (optional)

PT SS L4-S1 L5-S1 TK C2PA Global tilt

Evaluation mode

Select the model used to predict postoperative alignment.

Hybrid model uses published correction estimates for immediate postoperative alignment and cohort models for follow-up alignment. Cohort-based model predicts alignment from recorded patient and surgical variables.

Surgical preferences (optional)

Set permitted, excluded, and required procedures. Available options depend on the selected prediction model. The cohort model represents ALIF, XLIF, TLIF, and an osteotomy category controlled by the PSO option.

Maneuver	Allow	Forbid	Require
Interbody fusion / anterior column procedures
ALIF (Anterior lumbar)
ACR (Anterior column realignment)
XLIF (Extreme lateral)
OLIF (Oblique lumbar)
TLIF (Transforaminal)
PLIF (Posterior lumbar)
Osteotomies
PSO (Pedicle subtraction osteotomy)
SPO (Smith-Petersen / Ponte)
VCR (Vertebral column resection)

Max interbody fusion techniques:

Custom constraints (optional, layered on profile)

Allowed UIV / LIV range (optional). Leave any selector at "any" to skip that bound. When set, the GA cannot pick a UIV or LIV outside the range.

UIV from to

LIV from to

Instrumentation limits (optional). Select the checkbox to restrict the rod or pelvic screw count, then set the minimum and maximum. Leave it unchecked to use the model's full range.

Number of rods: 2-6

Pelvic screws: 0-4

Parameter	Target	Min	Max	Weight

Disc-space exclusions (optional)

Blocks interbody fusion (ALIF / XLIF / TLIF) and osteotomy from the selected disc spaces, without preventing the construct from spanning the level. Use when a specific disc is off-limits (e.g. prior failed ALIF at L4-5, vascular concern, infected disc).

Alignment targets Planning goal

Check every goal that should drive the GA. Combinations stack. For example, GAP + T4-L1PA weights both. Custom adds your surgeon-entered constraints (table below) on top. Surgeons who do not subscribe to a given framework should leave that checkbox unchecked.

Target assessment timepoint:

Search iterations (generations)

Live searches use a maximum of 4 generations to reduce timeout risk. Fewer generations may return fewer candidate plans.

Use precomputed plans

Compare your own plan

Enter a plan to explore its modeled alignment. Search exclusions do not apply to your manually entered plan. This preview does not establish surgical feasibility or achieved alignment. Any failure proxy score is not a validated patient risk estimate.

ALIF segments (anterior lumbar interbody fusion)

L2-3 L3-4 L4-5 L5-S1

XLIF segments (lateral lumbar interbody fusion)

L1-2 L2-3 L3-4 L4-5

TLIF (transforaminal lumbar interbody fusion)

TLIF (levels)

Osteotomy

Include osteotomy (PSO category) Level

Maneuver	Level	Δ LL (deg)	Supine corr	Reference

Enter the assumed change in lumbar lordosis (ΔLL) for each procedure. The model limits this value to the published range shown for that procedure and level. It also applies literature-based estimates of the effects of PSO, SPO, and VCR on T4PA and L1PA.

Posterior instrumentation

UIV level LIV level Include instrumentation factors in the mechanical failure proxy score UIV fixation Cement at UIV+1 # pelvic screws (S2AI / iliac) Pelvic fixation type Number of rods Rod material Cross-links between rods Rod diameter Derived: number of fused levels

Clicking Search candidate plans includes your entered plan alongside the generated candidates for comparison.

Penalty tuning (click rows to enable/disable or override weights)

Show / hide · default values shown · changes apply to next GA run only

Alignment-target soft penalties (Term 1)

Each row is one constraint. Toggle it to include or skip it. Weight is the multiplier for that constraint.

Use	Penalty	Weight	Reference

Mechanical-failure proxy factors (Term 2)

Each factor is a multiplier taken from published studies. Toggle it to include or skip it. The sizes are not shown here because they come from the cited papers.

Use	Factor	Reference

Anatomic-risk surcharges (Terms 3 and 4)

Extra fitness cost near the conus, the tapered lower end of the spinal cord. Toggle it to include or skip it. The size is a flat number added to the score.

Use	Surcharge	Magnitude	Reference

Each live search uses up to 4 generations to reduce timeout risk. Compare target strategies runs a separate search for each strategy, so the total wait can be longer. Runtime varies with the patient, restrictions, and server load.

Preoperative spine (live)

Updates as you change PI, LL, PT, L4-S1, TK.

Start with your alignment targets.

Patient parameters

Alignment-target soft penalties (Term 1)

Mechanical-failure proxy factors (Term 2)

Anatomic-risk surcharges (Terms 3 and 4)

Preoperative spine (live)

Your plan: predicted alignment

Candidate plans

Start with your alignment targets.

Patient parameters

Alignment-target soft penalties (Term 1)

Mechanical-failure proxy factors (Term 2)

Anatomic-risk surcharges (Terms 3 and 4)

Preoperative spine (live)

Your plan: predicted alignment

Candidate plans ?

Candidate plans