Updated March 16, 2015.

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The hamate bone is one of eight small bones of the wrist.  These eight bones are stacked neatly in two rows at the base of the hand (directly under the thicker parts of the palm).  Collectively, the bones are called the carpal bones--the word comes from the Latin word meaning "wrist."  Most people have heard of carpal tunnel syndrome, a condition where a nerve is pinched as it passes through a tight canal partly formed by the carpal bones.

Just like any other bone in the body, the carpal bones can be fractured when they experience abnormal stress or trauma.  The hamate bone is an unusually shaped bone.  Most of the bone is square shaped, but there is a projection on the palm side of the bone called the "hook of the hamate."  The hook is a small, narrow projection of bone, and it the attachment of ligaments and tendons in the wrist.

Fractures of the Hook of the Hamate

Fractures of the hook of the hamate are unusual.  Less than 2% of all carpal bone fractures involve the hook of the hamate.  However, these fractures are still worth discussing, as they can often be difficult to diagnose, and challenging to treat.

Fractures of the hook of the hamate typically occur in athletes who do a sport that involves gripping an object.  Baseball players, golfers, and hockey players sustain the vast majority of fractures of the hook of the hamate.  Typically, the athlete can remember an injury where they had an awkward check swing, or struck a golf club into a root or the ground.

 

Symptoms of Fractures

The most common symptom of a fracture of the hook of the hamate is pain.  Swelling, bruising, and weakness of grip are also common, but the most frequent symptom is pain.  The pain may be vague and difficult to reproduce, but should be found when an examiner presses directly on the hook of the hamate bone.  Often other causes of ulnar sided wrist pain may be considered, including TFCC tears, tendon or ligament injuries, or other fractures.

In more longstanding cases, symptoms may also include abnormal nerve function of the ulnar nerve.  The ulnar nerve is one of the major nerves supplying sensation to the hand and fingers.  The nerve passes just around the hook of the hamate, and often patients will experience numbness and tingling in the small and ring fingers when the ulnar nerve is not functioning normally.

Typical wrist x-rays usually look normal in patients with a fracture of the hook of the hamate.  There is a special view, called a carpal tunnel view, that better visualizes the hook of the hamate, making some fractures visible.  MRI and CT scans are more more sensitive at showing fractures of the hook of the hamate.  CT scans show better bone detail, whereas MRIs may be more helpful if the diagnosis is unclear, and the examiner wants to also evaluate cartilage, ligaments, and tendons.

Treatment Options

There are a few options for treatment of fractures of the hook of the hamate.  Use of a cast to immobilize the broken bone can sometimes be effective, but the results are not reliable.  Healing of the fracture may not occur, and patients are likely to need further treatment. 

Repair of the fracture is generally avoiding.  Healing of the bone can still be difficult to accomplish, and patients are often bothered by the hardware used to repair the broken bone.

The most common treatment, especially for an athlete, is to surgically remove the broken hook of the hamate.  The reliability of recovery from this surgery is very good.  Athletes typically take 6-8 weeks to recover from this surgery and return to sports.  There are possible complications of surgery, including nerve injury, infection, and pain, but when performed by an experienced surgeon is a very safe procedure.

<sub>Sources:

Slowman LS, and Morgan WJ. "Acute Hand and Wrist Injuries in Athletes: Evaluation and Management" J Am Acad Orthop Surg November/December 2001 vol. 9 no. 6 389-400</sub>