What Is the Pirani Score?
If your baby has been diagnosed with clubfoot (talipes equinovarus) and you've been to your first Ponseti clinic appointment, you may have heard the orthopaedic team mention a "Pirani score." It might have been written on your baby's notes: "Pirani 4.5" or "Pirani 3.0." But nobody explained what it means.
The Pirani scoring system is a way of measuring the severity of a clubfoot. It was developed by Dr Shafique Pirani, a Canadian orthopaedic surgeon, as a simple, reliable tool that doctors can use to:
- Assess how severe the clubfoot is at the start of treatment
- Track improvement during casting
- Decide when the foot is ready for the Achilles tenotomy
- Monitor for signs of relapse in follow-up
It's a 0-6 scale, where 0 is a perfectly normal foot and 6 is the most severe clubfoot. Most babies start treatment with a Pirani score of 3-6, and the goal is to reduce it to 0 or close to 0.
How the Score Is Calculated
The Pirani score assesses six features of the clubfoot, each scored 0, 0.5, or 1:
Hindfoot (Back of the Foot) — Three Components
| Component | Score 0 | Score 0.5 | Score 1 |
|---|---|---|---|
| Posterior crease | Multiple fine creases | One or two deep creases | Deep creases that change skin contour |
| Empty heel | Heel bone easily felt | Heel bone felt but reduced | Heel bone not palpable (empty) |
| Rigid equinus | Foot dorsiflexes easily | Some dorsiflexion but limited | No dorsiflexion at all |
Midfoot (Middle of the Foot) — Three Components
| Component | Score 0 | Score 0.5 | Score 1 |
|---|---|---|---|
| Medial crease | Multiple fine creases | One or two deep creases | Deep creases changing contour |
| Curved lateral border | Straight lateral border | Slight curve | Obvious curve (kidney bean shape) |
| Lateral head of talus | Covered (not palpable) | Partially covered | Fully uncovered (prominent bump) |
Total Pirani score = Hindfoot score (0-3) + Midfoot score (0-3) = 0 to 6
What the Scores Mean in Practice
- Pirani 0: A fully corrected foot. This is the goal. It means all six components are scoring 0 — the foot is in a normal position with good flexibility.
- Pirani 0.5-1: Almost fully corrected. Minor residual features that may still be improving with continued bracing.
- Pirani 1.5-3: Moderate severity. The foot has significant deformity but is within the range that Ponseti casting corrects well.
- Pirani 3.5-5: Severe clubfoot. More casts are likely needed. The hindfoot is significantly affected (rigid equinus, empty heel).
- Pirani 5.5-6: Very severe. All components are maximally affected. Treatment will work but may require more casts and possibly additional procedures. Atypical clubfoot often scores at this level.
How the Pirani Score Guides Treatment
During Casting
Your consultant will typically re-score the foot at each cast change. You should see the score decreasing week by week as the casts gradually correct the deformity. The components usually improve in a specific order:
- Curved lateral border corrects first (the foot straightens)
- Lateral head of talus becomes covered
- Medial crease smooths out
- Posterior crease improves
- Empty heel fills (the heel bone drops down)
- Rigid equinus corrects last (often requiring tenotomy)
Deciding on Tenotomy
The Pirani score helps determine when the foot is ready for an Achilles tenotomy. Typically, the tenotomy is performed when:
- The midfoot score has reached 0 or close to 0
- The only remaining issue is rigid equinus (the foot can't flex upward)
- The hindfoot score is dominated by the equinus component
In practical terms, this usually means a total Pirani score of about 1 (with almost all of it coming from the rigid equinus component).
Monitoring for Relapse
After treatment, the Pirani score is re-checked at follow-up appointments. Any increase in the score suggests the foot is starting to relapse, and early intervention can be planned.
Limitations of the Pirani Score
The Pirani score is useful but not perfect:
- It's subjective. Different assessors may score the same foot slightly differently, particularly for the 0 vs 0.5 distinction.
- It doesn't capture everything. The score doesn't assess calf muscle size, foot size, or overall flexibility in detail.
- Initial severity doesn't predict final outcome. A foot with a Pirani score of 6 can end up just as good as a foot with a Pirani score of 3 after treatment. Don't be disheartened by a high initial score.
- It's most useful for tracking progress rather than for absolute assessment. Watching the score decrease over the casting weeks is the most valuable use.
Another Scoring System: The Diméglio Score
Some UK clinics use the Diméglio classification instead of (or alongside) the Pirani score. The Diméglio system is a 0-20 scale that also assesses flexibility and severity but uses a different methodology. Both systems are valid, and your clinic will use whichever they're most experienced with.
Frequently Asked Questions
My baby's Pirani score is 5. Is that very bad?
A Pirani score of 5 is at the severe end, but it doesn't predict the outcome. Severe clubfoot responds just as well to Ponseti treatment — it may simply need more casts. Try not to focus on the number and instead watch it decrease over the weeks.
How quickly should the Pirani score decrease?
Typically, the score drops by 0.5-1.0 per cast. But this isn't linear — sometimes there's a big improvement in one week and little change the next. The overall trend matters more than individual week changes.
My consultant doesn't mention the Pirani score. Should I ask?
Not all clinics routinely share the score with parents. If you'd like to know, absolutely ask — it's your child's clinical information and you're entitled to it. Tracking the score can be reassuring as you see the numbers improve.
Does a Pirani score of 0 mean the clubfoot is cured?
A Pirani 0 means the foot is currently in a fully corrected position. It doesn't mean "cured" — the foot still needs boots and bar to maintain the correction, and regular monitoring for relapse continues for years. Think of Pirani 0 as "fully corrected" rather than "cured."
Is the Pirani score used for both feet in bilateral clubfoot?
Yes, each foot is scored independently. Your notes may show two separate scores if your baby has bilateral talipes.