Degenerative Spondylolisthesis With Neurogenic Claudication

Diagnosis: Grade I degenerative spondylolisthesis at L4–L5 with degenerative canal stenosis, producing a neurogenic claudication picture.

• Meyerding grade: 9 mm is well under 25% of the L5 body width - Grade I.
• Intact pars distinguishes this from isthmic spondylolisthesis. This is degenerative: facet hypertrophy and disc height loss with an intact neural arch, at the level and in the age group where it is most common (L4–L5, older adult).
• The 2 mm of dynamic translation (9 → 11 mm) is within measurement error. The conventional radiographic threshold for abnormal translation is roughly >3 mm, and angular change >11°. Two millimeters on two separate films, measured by different people at different times, is not a finding - it is noise. State plainly that this is not a positive instability study.

What it does mean: the listhesis is essentially fixed, and the symptoms are being driven by canal narrowing and compression under extension, not by abnormal motion. The history is textbook - relieved by flexion and sitting, provoked by standing, walking, and extension, negative tension signs, no radicular or myelopathic deficits.

What it does not mean: it does not mean the segment is unstable, does not require surgery, and does not by itself contraindicate mobilization. It also does not tell you the canal diameter - plain films cannot.

Worth ruling out before settling: vascular claudication (check distal pulses, ask about symptom relief on standing still versus sitting, consider ABI), hip osteoarthritis, and peripheral neuropathy.

Yes - not emergently, but now.

For imaging:

• Two-block walking tolerance is a functional threshold. He is restricted in a way that alters his life and his options.
• Plain films cannot quantify the canal, ligamentum flavum, or facet contribution, and cannot show whether there is a synovial cyst or lateral recess compromise.
• The result changes management: it determines whether he is a candidate for structured conservative care, an epidural, or a surgical referral, and it gives the surgeon a baseline.
• Six months of symptoms with a clear mechanical pattern is a reasonable point to stop guessing.

Against imaging (the honest counter-argument):

• No red flags, no progressive neurological deficit, no saddle symptoms, no bowel/bladder change. Nothing here requires a same-day scan.
• If he were 3 weeks into symptoms and improving, an MRI would be premature.

So the answer is sequencing, not yes/no: order MRI lumbar spine without contrast, non-urgent, and continue conservative care in the meantime. Escalate to urgent/emergent if he develops bowel or bladder dysfunction, saddle anesthesia, rapidly progressive weakness, or bilateral leg symptoms.

Also: do not repeat the radiographs. The dynamic films have been done and have answered their question.

Technique changes:

• Avoid extension-based positioning, and avoid high-velocity rotation/extension through L4–L5. His canal is narrow and extension is his provocation; you would be reproducing the mechanism of his symptoms, not treating them.
• Use a flexion-bias: flexion-distraction, side-lying or supine with hips and knees flexed, and soft-tissue work to the lumbar and gluteal region.
• Do not treat a fixed listhesis with the goal of “putting it back.” It will not reduce, and chasing reduction invites excessive force.
• Build a program: flexion-biased mobility, core and hip strengthening, a graded walking program (start below his two-block limit and build), and a stationary bicycle if available - flexion-bias aerobic exercise is the single most useful intervention here.
• Do not be timid about mobilization on the basis of that 2 mm. There is no demonstrated instability; unnecessary immobilization will cost him function.

Prognostic conversation:

“The slip is stable - the bending films move only about 2 mm, which is measurement noise, not instability. What's actually causing your leg pain when you walk is that the canal narrows when you stand up straight. That means our target is your walking tolerance and your strength, not the position of the vertebra. Most people improve with a structured program over 6–12 weeks; if your walking distance keeps shrinking or you develop numbness, weakness, or bladder changes, that's when we escalate.”

Set a review point: re-measure walking tolerance at 4 and 8 weeks. Failure to improve → refer.

Document: the imaging interpretation, the rationale for a flexion-biased approach, the red-flag instructions given, and the review date.