3 Things an Expert’s Sciatica Misdiagnosis Can Teach Us

It’s easy to look back on a mistake or misdiagnosis and cringe a little. But it’s also one of the most powerful ways we grow as clinicians.

Every physio has had those moments, the case that seemed clear-cut until it wasn’t. In his Case Study, expert physio Tom Jesson outlines his experience with a sciatica misdiagnosis, missing a red flag and how he managed it. This case is a great reminder that the experts are only human too! What matters is their ability to reflect and learn from mistakes.

This blog outlines 3 things we can all take away from Tom’s case of misdiagnosis, let his learning curve improve your practice!

If you want to see exactly how an expert physio assessed and managed a real patient with vascular issues masquerading as sciatica, check out Tom’s full Case Study HERE. With Case Studies you can step inside the minds of experts and apply their strategies to get better results with your patients. Learn more here.

The case

A man in his mid-50s presented with six weeks of low back and left leg pain. The symptoms had started in his calf and gradually moved upward. He reported pain with bending, lifting, and after walking more than about 150 yards.

On objective assessment, he exhibited a diminished ankle jerk, reduced knee sensation, and a positive straight leg raise. Based on this presentation, Tom diagnosed sciatica, a reasonable conclusion given the findings, and particularly so as the patient already had a history of sciatica!

But in fact, he was missing a common red flag – Peripheral Artery Disease (PAD). Before we get into what this case can tell us, see Tom give a little refresher on PAD in this clip from his Case Study:

What we can learn

1 – Beware of “MSK brain”

Tom puts it perfectly when he says he was stuck in musculoskeletal thinking.

The patient had a history of sciatica, and that narrative fit neatly with what he was hearing and seeing. It’s a trap we all fall into, especially when it’s our last of 15 patients for the day!

What he missed was the key detail that the leg pain only came on after about 150 yards of walking, a classic exertional clue. In hindsight, it was the key piece of information pointing away from a nerve root irritation and toward a vascular cause. It’s a good reminder that when symptoms fit too perfectly into an MSK story, it’s worth pausing to consider whether we need to take a step back and look at the broader picture.

2 – Be specific with your subjective

The patient reported pain with bending, lifting, and walking – all common aggravators for sciatica.

But Tom later recognised he hadn’t been specific enough about which type of pain came on with each activity. Was his back pain aggravated by walking, or was it just the leg pain? How long did it take to settle once he stopped? Those details could have revealed that his walking tolerance, not his lumbar loading, was the true driver of the patient’s leg symptoms.

He also acknowledged missing one key red flag screening question, part of what he calls the “Plaque 5”. These are the big five risk factors for PAD: smoking, diabetes, dyslipidemia, high blood pressure, and atherosclerotic disease. Asking about these takes seconds, but it can completely change your diagnostic direction. It turns out that the patient was in fact a heavy, long-term smoker, something which may have tipped Tom off to a vascular issue if he had asked in that first session.

Useful tip: If you have a patient with leg pain that is exertional AND predictable (e.g., always stops within 10 minutes of ceasing exertion) then you should be suspicious of PAD!

3 – Objective assessment red herrings

If you’re already in your MSK brain throughout the subjective, it can be easy to fit the objective to meet your bias.

The objective findings of reduced reflex, altered sensation, positive straight leg raise all pointed toward sciatica. But many middle-aged patients with a history of sciatica will show mild neural findings even when their current pain has a different cause.

For PAD, the most objective test we can do is pulse testing. Don’t know how? No worries, Tom explains how to do this in the below video from his Case Study:

Wrapping up

This case is a great reminder that our biggest diagnostic challenges don’t usually come from rare conditions, they come from the common ones that look familiar. When we default to our “MSK brain,” it’s easy to miss things.

The takeaway? Stay curious. Ask the next question. Be specific, and never let a confident first impression close the door on alternative possibilities.

If you’d like to see exactly how Tom unpacked the case and reflected on his process, and ultimately treated his patient with PAD, watch his full Case Study HERE.