Open Fracture of the Hook of the Left Hamate Jamie McDonald Case Study

Outline Open Fracture to Hook of Left Hamate Ulnar Artery Causes Symptoms & Complications Treatment Ulnar Artery Pathway Relation to Ulnar Nerve Clinical Application

The hamate bone is a triangular-shaped bone composed of a body and a hook. Hamate fractures are classified as type 1 fractures involving the hook.

Causes Type 1 fractures involving the hook of the hamate are most common. Repeated microtrauma to the hook during sports involving swinging clubs, bats, or racquets. Direct trauma can occur when the butt of the club rests on the hamate, and the force from the swing transfers directly to the bone. Indirect trauma can occur by falling on a hyper-extended wrist or during power grips, thus injuring the muscles and ligaments.

Symptoms & Complications Pain in wrist. Decreased grip strength. Pain on palpation of the hook of the hamate. Numbness in fourth and fifth fingers. Tenderness on the palm side of wrist. Pain on the little finger side of wrist Complications: Damage to the ulnar nerve and artery. Infections

Treatment Open Reduction (surgery): Only necessary if there is a deformity; completed through an incision and use of pins and screws. Physical & Occupational Therapy: joint mobilizations; soft tissue massages; ultrasound; bracing; strength activities. Immobilization in a short arm cast for at least 6 weeks. Ultrasound

Ulnar Artery The ulnar artery leads down the ulnar side of the forearm to the wrist, supplying blood to the flexor and extensor muscles in the lower arm. Branches of the ulnar and radial arteries combine at the wrist to supply structures in the wrist, hand, and fingers.

Ulnar Nerve The ulnar nerve is a branch of the brachial plexus nerve system. It helps provide motor movement to the flexor muscles of the hand, allowing bending.

Relation The ulnar nerve travels through cubital tunnel on the medial side of the elbow. It supplies the flexor carpi ulnaris and the flexor digitorum profundus muscles and courses with the ulnar artery. At the hand, the ulnar nerve enters through the Guyon’s canal. If the ulnar nerve is damaged at the wrist, the ulnar claw can result.

What Is Ulnar Claw? A deformity that is seen in ulnar nerve damage at the wrist. Affects the little and ring finger of the hand. When the medial lumbricals are paralyzed, flexion is lost at the MCP joints and extension is lost at the IP joints. MCP joints are hyper-extended. IP joints are flexed. There is an imbalance between the intrinsic and extrinsic muscles of the hand.

Intrinsic muscles- curling of fingers Extrinsic muscles- stretches MCP joints backwards Lumbrical Position in splint for MCP joints

The Case Patient is a 49 year old male in good health. Victim of a gunshot wound to the left hand. Open left fracture of the hook of the hamate. Reports the chief complaint is pain, decreased range of motion, and decreased strength in the left hand and wrist. Surgery performed on May 21, 2016.

Hand before surgery was performed.

X-ray before surgery: fracture of the hook of the hamate.

History Gun shot to hand 5/20/16: Surgery 5/21/16: Dorsal Blocking splint fabricated 5/24/16: 1st day of therapy Last day seen 6/22/16: Beginning of ulnar clawing 6/7/16:

Post-Surgery Cast on hand, wrist, and forearm to prevent: Intrinsic minus: bad positioning in splint Hand held in lumbrical plus position with dorsal blocking splint. MCP joint flexion IP joint extension Nerve response to injury: Dry, callus skin Peeling Discharge and pale color

X-ray after surgery

Post surgery ulnar clawing: MCP joints are hyperextended; IP joints are flexed

Dorsal Blocking Splint

Occupational Therapy Correct positioning in dorsal blocking splint. Stretching of extrinsic flexors and extensors to prevent tightness. If MCP joints collateral ligaments are taught- extension- leads to stiff joints If MCP joints are lengthened- flexion- range of position is promoted Goal of therapy is for the thumb to touch the tip of the pinky.

What’s Next? Last day seen in therapy was 6/22/16. Ulnar nerve: Continues to repair itself Will grow 1 inch per month, following the first month. Range of motion: When the fingers gain ROM back, therapy will incorporate more strengthening exercises. Possible deformity of hand and loss of wrist/hand movement.

References http://emedicine.medscape.com/article/97813-overview#a6 http://www.epainassist.com/sports-injuries/wrist- injuries/fracture-of-hook-of-hamate http://www.innerbody.com/image_cardov/card37- new.html#full-description http://www.hopkinsmedicine.org/neurology_neurosurgery/ce nters_clinics/peripheral_nerve_surgery/conditions/ulnar_ner ve_entrapment.html http://teachmeanatomy.info/upper-limb/nerves/ulnar-claw-vs- hand-of-benediction/ Ulnar Intrinsic Anatomy and Dysfunction Dell, Paul C.Sforzo, Christopher R. et al. Journal of Hand Therapy , Volume 18 , Issue 2 , 198 – 207.