Here are the answers for Questions 50-55 from your Exercise Therapy MCQ sheet, verified against standard orthopedic references:

Q50. Most common nerve damage in shoulder dislocation Answer: B. Axillary nerve In anterior shoulder dislocation, the axillary nerve (which wraps around the surgical neck of the humerus) is the most frequently injured nerve, producing deltoid weakness and a patch of sensory loss over the "regimental badge" area.

Q51. Deformity seen in congenital dislocation of the knee Answer: D. Extension Congenital dislocation of the knee (congenital genu recurvatum) presents with a fixed hyperextension deformity of the knee at birth, due to the tibia dislocating anteriorly on the femur; this is quite different from congenital dislocation of the hip.

Q52. Earliest visible change in osteoarthritis Answer: B. Fibrillation The question specifically asks for the earliest visible change (as seen grossly/arthroscopically on the cartilage surface). While biochemical changes such as increased water content and proteoglycan loss occur first at the molecular level, the earliest visible morphological change on the cartilage surface is fibrillation (fraying/roughening), which precedes fissuring, erosion, and eburnation.

Q53. Earliest sign of Volkmann's ischemic contracture Answer: A. Pain on passive extension This corresponds to pain with passive stretch of the fingers, which is the earliest and most sensitive clinical sign of impending compartment syndrome/Volkmann's ischemic contracture, appearing before pallor, pulselessness, or paralysis. This is confirmed in Sabiston's Textbook of Surgery and Miller's Review of Orthopaedics, which describe pain out of proportion (worsened on passive stretch) as the classic early warning sign of compartment syndrome preceding established Volkmann contracture (- Sabiston Textbook of Surgery; Miller's Review of Orthopaedics, 9th Ed.).

Q54. Most commonly involved structure in Dupuytren's contracture Answer: B. Pretendinous bands The pretendinous bands of the palmar fascia (which normally lie superficial to the flexor tendons) are the structures most commonly affected, thickening into pathological "pretendinous cords" that produce MCP joint flexion contractures, most often affecting the ring and little fingers.

Q55. Most common organism causing hematogenous osteomyelitis in children Answer: D. Staphylococcus Staphylococcus aureus is by far the most common causative organism in acute hematogenous osteomyelitis in children, typically seeding the metaphysis of long bones via the bloodstream.

A note on Q52: some answer keys list "A. Loss of water" if the question is interpreted as asking for the earliest biochemical change rather than the earliest visible one - if your textbook's answer key differs, it likely hinges on that distinction (biochemical vs. morphological "earliest" change). Worth double-checking against the exact wording/answer key in your Maheshwari 3rd Ed., p. 252 source, since I don't have that specific title in the indexed library to confirm verbatim.