**Core Concept**
Pirani scoring is a system used to assess the severity of congenital talipes equinovarus (CTEV), also known as clubfoot. This scoring system evaluates the deformity's severity in terms of joint contractures, soft tissue tightness, and bony deformities.

**Why the Correct Answer is Right**
The Pirani scoring system assesses CTEV by evaluating five key components: the medial and lateral collateral ligaments, the Achilles tendon, the posterior capsule of the talus, and the posterior capsule of the calcaneus. This scoring system helps orthopedic surgeons and physiotherapists to determine the optimal treatment approach for each patient.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not listed as the scoring system evaluates the deformity in terms of joint contractures, soft tissue tightness, and bony deformities, but does not include the plantar fascia.
**Option B:** The heel-to-toe length discrepancy is not a component of the Pirani scoring system.
**Option C:** The posterior tibial tendon is not evaluated in the Pirani scoring system.

**Clinical Pearl / High-Yield Fact**
The Pirani scoring system is a valuable tool for assessing the severity of CTEV, but it is essential to remember that each patient's deformity is unique, and a thorough examination is necessary to determine the best treatment approach.

**Correct Answer:** D.