In which of the following deformities is the distal interphalangeal joint flexed and proximal interphalangeal joint extended?
**Core Concept:** Distal interphalangeal (DIP) joint flexion and proximal interphalangeal (PIP) joint extension is a key feature of specific types of congenital hand deformities.
**Why the Correct Answer is Right:**
Correct Answer: D. Dupuytren's Contracture
Dupuytren's Contracture is a fibromuscular disease that causes the fingers to bend towards the palm, leading to DIP joint flexion and PIP joint extension. The condition primarily affects the palm side of the fingers and is caused by abnormal proliferation of collagen-producing cells called fibroblasts. This abnormal collagen deposition results in contractures, which are rigid, immovable deformities.
**Why Each Wrong Option is Incorrect:**
A. Pollicis Longus Contracture: This is a condition where the thumb is affected leading to flexion at the PIP joint and extension at the MCP joint, not the opposite.
B. Flexor Digitorum Profundus Tendon Contracture: This condition causes flexion at both PIP and MCP joints, not the opposite as in Dupuytren's Contracture.
C. Transverse Ulna Fracture: This is a fracture of the ulna bone and does not result in the specific joint deformity described in Dupuytren's Contracture.
**Clinical Pearl:** Dupuytren's Contracture often presents in late middle age or older and is more common in men. Treatment options include physiotherapy, corticosteroid injections, and surgery, depending on the severity of the contracture. Early diagnosis and intervention are crucial to prevent the condition from progressing and causing significant disability.