Hamate Fractures

Concern exists that hook excision will weaken grip. Evidence shows:

• Grip strength averages 80-90% of contralateral after excision
• No significant difference in hook excision vs ORIF for athletes
• Larger handle diameter compensates for any weakness
• Return to elite golf and racquet sports documented
• Patient satisfaction high despite measurable decrease

Bottom line: Grip strength reduction is minimal and well-tolerated, especially compared to ongoing pain or tendon rupture risk with nonunion.

In a grip-trauma patient with ulnar-sided hand symptoms, think beyond the bone and the nerve to the ulnar artery. The ulnar artery runs superficially through Guyon's canal directly over the hook, so the very same repetitive palmar trauma that fractures the hook - and the sharp fracture fragment itself - can damage the vessel, producing ulnar artery thrombosis or pseudoaneurysm: hypothenar hammer syndrome. It affects the same population (athletes and manual workers who use the heel of the palm as a hammer - mechanics, carpenters, golfers, baseball/hockey players).

Q: A golfer presents with hypothenar pain after hitting the ground during a swing. Plain radiographs are normal. What is the best next investigation?

A: CT scan of the wrist. Hook of hamate fractures are notoriously difficult to visualize on plain radiographs (50% sensitivity). CT has 95-100% sensitivity for hook fractures and is the gold standard imaging modality.

Q: Which neural structure passes through Guyon's canal and is most at risk with hook of hamate fractures?

A: The motor branch of the ulnar nerve (deep branch). The hook of hamate forms the radial wall of Guyon's canal. Injury causes weakness of intrinsic muscles (interossei, hypothenar muscles) without sensory loss in Zone II injuries.

Q: A baseball player presents 6 weeks after injury with persistent hypothenar pain. CT confirms hook of hamate nonunion. What is the recommended treatment?

A: Hook excision. Hook of hamate nonunion has a 50% rate with conservative management. Excision reliably resolves symptoms with excellent outcomes, allows return to sport in 6-8 weeks, and eliminates the risk of FDP tendon rupture from the sharp nonunion fragment.

Q: What tendon is at risk of rupture with an untreated hook of hamate fracture, and what is the reported rupture rate?

A: The flexor digitorum profundus (FDP) tendons to the ring and small fingers are at risk due to their close proximity to the hook. Untreated nonunion has a 20% FDP rupture rate due to attrition from the sharp fracture fragment.

Q: What distinguishes hook of hamate fractures from body of hamate fractures in terms of mechanism and treatment?

A: Hook fractures result from direct impact during grip sports (golf, baseball) and are often treated with excision if symptomatic or nonunion develops. Body fractures result from high-energy trauma, often with associated CMC injuries, and require ORIF to restore carpometacarpal articulation.

Q: Where is the hook of hamate palpated on clinical examination?

A: The hook is palpated 2cm distal AND radial to the pisiform. It forms the ulnar border of the carpal tunnel and the radial wall of Guyon's canal. Point tenderness at this location with grip weakness is highly suggestive of hook fracture.