20250902 Extensor tendon injuries Dr Jo Yi

Of the extensor tendon compartments on the dorsum of the wrist, which of the following is true?:

• A. The extensor pollicis longus (EPL) alters direction around the ulnar styloid

• B. The extensor indicis proprius (EIP) shares a compartment with extensor digitorum communis (EDC)

• C. The first compartment contains the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB)

• D. The posterior interosseous nerve runs in the third compartment

• E. The extensor carpi ulnaris (ECU) and extensor digiti minimi (EDM) share the fifth compartment

A 50-year-old patient sustained an injury to his left index finger one month ago. He sought treatment at the hand clinic after noticing a deformity of the finger. The initial event in the evolution of the development of the deformity is:

• A. Lateral and palmar migration of extensor lateral bands

• B. Laxity or rupture of PIP joint volar plate

• C. Hyperextension of the DIP joint

• D. Loss of continuity of the central slip insertion into the back of the base of the middle phalanx

• E. Flexion contracture of the PIP joint

A carpenter presented to emergency department with a cut wound at his right middle finger. Upon examination, the wound is located at the dorsal aspect of middle finger. He still able to perform full active extension of middle without extension lag.

Exploration was done in operation theater noted zone 3 central slip cut. The tendon was repaired with standard repair fashion. What is the advisable post operative rehab protocol?

• A. Yoke splint

• B. PIPJ extension splint 4 weeks then passive ROM exercise

• C. PIPJ extension splint 6-8 weeks with active DIPJ flexion exercises

• D. Buddy splint to index finger 6-8 weeks

• E. Mallet splint

Which of the following is true about tendon healing?

• A. Tendons are weakest at Days 14-21 post repair

• B. Fibroblasts produce Type I collagen during inflammation stage

• C. Fibrin clot and fibronectin stabilizes torn edges during the proliferation stage

• D. There is large amounts of disorganized collagen with angiogenesis in the remodelling stage

• E. Tissue remodelling replaces Type III collagen with Type I collagen

A 28-year-old male sustains a laceration to the dorsal aspect of his right hand during an assault as shown in Figure A. He is unable to actively extend his middle finger. He undergoes primary repair of the injured structure and is placed into the relative motion splint (yoke splint) shown in Figure B. All of the following are benefits of the splint compared to a full-time extension splint except:

• A. Interferes with activities of daily living

• B. Better at limiting motion of the affected digit

• C. Reduces risk of adhesions

• D. Allow more range of motion of adjacent digits

• E. Higher patient compliance with therapy