Pirani Score

Original Editor - Africa Clubfoot Training Team as part of ICRC and GCI Clubfoot Content Development Project

Top Contributors - Naomi O'Reilly, Kim Jackson, Rachael Lowe, Simisola Ajeyalemi, Rucha Gadgil and Meaghan Rieke  

Objective

Pirani scoring system is a simple and reliable system to determine severity and monitor progress in the treatment of clubfoot. 

Developed by Shaque Pirani, a Canadian Orthopaedic Surgeon, who assisted in the development of clubfoot services in Uganda and Malawi, it is an easy to use tool, developed to assess the severity of each of the individual components of Clubfoot. It is used both as a means to assess the severity of the Clubfoot at initial presentation and for ongoing monitoring of the patients’ progress. An increase in the Pirani Score between visits may be an indication that a relapse of deformity is occurring. 

Intended Population

The Pirani Score is intended for use as a means to assess the severity of the clubfoot at initial presentation and for ongoing monitoring of the patients’ progress.

Methods of Use

The Pirani Scoring System is based on 6 well-described Clinical Signs of Contracture characterizing a severe clubfoot:

• If the sign is severely abnormal it scores 1
• If it is partially abnormal it scores 0.5
• If it is normal it scores 0

Scoring the foot at each visit during treatment enables the health care worker treating the child to document how the foot is responding to manipulation and casting.Many degrees of severity and rigidity of Clubfoot are found at birth. Failures in treatment are related more often to faulty technique of manipulation and casting rather than severity of deformity.

Technique

The examiner is seated. The infant is on the mother’s lap. A feeding, relaxed infant allows a more precise examination. The measurements are made while the examiner is gently correcting the foot with minimal effort, and no discomfort.

The Pirani Score key features:

1. Six “Signs” are Assessed
   • Scored depending on Severity - 0, 0.5, or 1
   • 3 Signs in Midfoot
   • 3 Signs in Hindfoot
2. Total Score (TS) varies from 0 to 6 and is the sum of Midfoot and Hindfoot Contracture Scores:

Midfoot Contracture Score (MFCS)

Varies between 0 and 3 with 3 signs each scored 0, 0.5, or 1

1. Medial Crease (MC)
   1. • Gently correct the foot, e.g. by lifting the foot holding the second toe
      • Assess the depth of the crease and the presence of other creases
      • The presence of several fine creases is scored 0, two or three moderate creases is scored 0.5, and a single, deep crease where you cannot see the bottom is scored 1.
2. Curved Lateral Border (CLB)
   1. • Make sure the child’s foot is relaxed
      • Observe from the plantar aspect, and use a pen held against the lateral edge of the calcaneum
      • Assess the point on the lateral border of the foot at which it deviates from a straight line
      • If the border of the foot (excluding the phalanges) is straight and without deviation, score 0. If it deviates at the level of the metatarsals, score 0.5. If it deviates at the calcaneo-cuboid joint, score a 1.
3. Lateral Head of Talus (LHT)
   1. • Palpate the head of the talus with the foot uncorrected (it may be easier to find initially if you move the foot into a more deformed position)
      • Keeping your finger / thumb on the talus, gently correct the foot
      • If the talus completely sinks away under the navicular, score 0. If it moves partially but doesn’t completely sink, score 0.5. If it remains fixed and does not sink, score 1.

Hindfoot Contracture Score (HFCS)

Varies between 0 and 3

3 signs are each scored 0, 0.5, or 1

1. Posterior Crease (PC)
   1. • Gently correct the plantarflexion (equinus)
      • Assess the depth of the crease and the presence of other creases
      • The presence of several fine creases is scored 0, two or three moderate creases is scored 0.5, and a single, deep crease where you cannot see the bottom is scored 1.
2. Empty Heel (EH)
   1. • Hold the foot in mild correction and palpate with a single index finger
      • Ascertain how much flesh there is in the heel between your finger and the calcaneum
      • If it is easy to palpate the calcaneum, which is not far under the skin, score 0. Score 0.5 for a palpable calcaneum which is just felt through a layer of flesh. If the calcaneum is deep under a layer of tissue and very difficult to feel, score 1. (0 is like touching your own chin, 0.5 like touching the tip of your nose, and 1 like touching the soft part of your palm below the base of your thumb).
3. Rigid Equinus (RE)
   1. • Correct the plantarflexion as much as is comfortable for the child, holding the knee straight
      • Assess the degree of dorsiflexion obtained: able to dorsiflex beyond plantigrade = 0, able to reach plantigrade (or 90°) = 0.5, unable to reach plantigrade (or 90°) = 1.

Recording

The Pirani score should be recorded at each visit during the correction phase of clubfoot treatment. Most clinics have a paper form to record it. Appendix D is an example of the CURE clubfoot form to record and display the history, physical examination, and treatment.

Putting the Pirani Score into a Graph:

• If the midfoot contracture score (MFCS), the hindfoot contracture score (HFCS), and the total score (TS) are plotted on a simple graph against time, you can follow the improvement of the foot.

Use of Pirani Score to indicate Tenotomy:

• Achilles Tenotomy which is the final part of correcting a clubfoot. The Pirani score can indicate when the foot is ready for a tenotomy. The graph below shows the effects of Ponseti treatment and tenotomy on the MFCS, HFCS, and TS. The MFCS drops rapidly with manipulation and casting whereas the HFCS remains high. The tenotomy is done in week 5 when the MFCS has dropped to 0 but the HFCS remains greater than 1. After the tenotomy, the HFCS improves from 2.5 to 0.5, but does not correct completely.

Evidence

The Pirani Scoring system has been found to be both valid and reliable, unlike many other Clubfoot Scoring Systems, which are untested. . A higher Pirani Score on presentation may indicate that a higher number of casts will be required, and as such can play a key role as a means for predicting treatment outcomes. In a child with a high initial Hindfoot Contracture Score (HFCS) the likelihood to experience relapse of deformity during the bracing phase is such higher than in those with lower scores and should have close monitoring with special emphasis put on the importance of the use of Foot Abduction Brace when educating parents/carers.

Reliability

Mejabi et al described the Pirani scoring system as a reliable system to determine severity and monitor progress in the treatment of clubfoot. Their study showed significant correlation (p<0.001) between the midfoot score, hindfoot score, Pirani score and the number of casts to achieve correction. Also, there was correlation between the Pirani score and the need for tenotomy (p<0.001) and the progress of treatment can be monitored with the Pirani score (p<0.001).

Validity

Piarani et al demonstrated validity of the Piarni Score with excellent inter-observer reliability by evaluating this clinical scoring system by correlating MRI and clinical scores.

Responsiveness

Resources

Pirani Scoring Sheet - http://globalclubfoot.org/wp-content/uploads/2011/02/Pirani-score-form.pdf

References