**Question:** Cocket and Dodd’s operations for

A. Dupuytren's contracture
B. Lister's gangrene
C. Peroneal nerve palsy
D. Hallux rigidus

**Correct Answer:** D. Hallux rigidus

**Core Concept:**
Cocket and Dodd's operations are a series of surgical procedures primarily used to treat Hallux rigidus, which is a form of degenerative arthritis affecting the first joint of the big toe (interphalangeal joint) in the foot. These operations aim to relieve pain and restore function to the affected joint.

**Why the Correct Answer is Right:**
1. Dupuytren's contracture is a fibromatosis causing finger flexion contractures.
2. Lister's gangrene is a severe necrotizing infection involving skin, subcutaneous tissue, and underlying structures.
3. Peroneal nerve palsy results in weakness or paralysis of muscles innervated by the peroneal nerve.
4. Hallux rigidus refers to a degenerative arthritis leading to rigidity and limited motion in the first MTP joint (metatarsophalangeal joint) in the foot.

**Why Each Wrong Option is Incorrect:**
1. Dupuytren's contracture is a congenital or acquired disorder involving the palmar fascia, not related to the foot joint.
2. Lister's gangrene is a rare and severe type of necrotizing infection involving soft tissues and bones. It is unrelated to joint conditions.
3. Peroneal nerve palsy results in weakness or paralysis of muscles innervated by the peroneal nerve, not related to joint conditions in the foot.
4. Hallux rigidus refers to a degenerative arthritis affecting the first MTP joint of the foot, which is the correct answer.

**Core Concept (Expanded):**
Hallux rigidus is a degenerative arthritis affecting the first MTP joint (metatarsophalangeal joint) in the foot, leading to rigidity and limited motion. This condition is commonly caused by wear and tear (osteoarthritis) or traumatic injury to the joint. The purpose of the Cocket and Dodd operations is to relieve pain and improve function in patients suffering from Hallux rigidus.

**Why the Correct Answer is Right:**
Cocket and Dodd's operations are named after the surgeons who first described these procedures, Dr. John Cocket and Dr. A.H. Dodd. These operations were developed to address the symptoms and functional limitations associated with Hallux rigidus. By performing these operations, the aim is to relieve pain in the affected joint, increase joint mobility, and improve overall function of the foot.

**Why Each Wrong Option is Incorrect:**
1. Dupuytren's contracture is a condition characterized by thickening and contracture of the palmar fascia, not related to joint conditions in the foot.
2. Lister's gangrene is a severe necrotizing infection involving soft tissues and bones, unrelated to joint conditions in the foot.