Hook of Hamate Fracture

January 12, 2012 by

History of present illness:

This patient is a 22-year-old gentleman, who works as a barista in a coffee shop. Over the course of  two-and-a-half weeks, he developed increasing numbness and tingling in his left small finger. It wakes him up at night. He has not noticed weakness. He has done some stretching exercises and taken naproxen. This has not improved his symptoms significantly. He does not recall any particular injury or incident in the past.  He reports similar symptoms on the right side, but to a lesser degree.

Physical examination:

Physical exam of the upper extremities demonstrates strong thenar and intrinsic muscles. He has a negative Froment’s sign, negative Wartenberg’s sign. Carpal tunnel compression test produces paresthesias. There is some vague tenderness over the hook of the hamate. Cubital tunnel compression does not produce paresthesias, but compression at Guyon’s canal at the wrist produces tingling in the small finger.

Two point discrimination on the right side is 4 mm and small finger is 6 mm. On the left side, two point discrimination is 4 mm in all fingertips. There is normal finger range of motion bilaterally. All fingers are well-perfused. Allan’s test shows an open palmar arch.

Radiographs of the wrists including a carpal tunnel view suggested a nonunited fracture of the hook of the hamate bilaterally. Further evaluation with MRI scan confirmed the diagnosis.

Hook of hamate fracture nonunion on carpal tunnel view

Electrodiagnostic tests revealed a mild degree of carpal tunnel syndrome.

Treatment:

The patient underwent operative excision of the ununited fragments of the hook of the hamate, combined with endoscopic carpal tunnel release.  No other pathology within Guyon’s canal was noted.

The patient was symptom free after recovery and a course of about 6 weeks of occupational hand therapy.

Review:

Hook of the Hamate fractures are rare, but often missed resulting into nonunion.  The mechanism of injury is often athletes that use rackets or bats or clubs.  In the acute phase simple cast or splint immobilization of the wrist will result into union.

Patient present with pain in the hypothenar eminence, tenderness to palpation, weak grip, and paresthesias of the ring and small fingers. Pain with resisted finger flexion is greater with the wrist in ulnar than in radial deviation. Because the hook of the hamate constitutes the ulnar wall of the carpal tunnel acting as a tendon pully, the flexor tendons of the ring or small finger can attenuate and even rupture, causing loss of active finger flexion.

Radiographically, the fracture can be demonstrated by a carpal tunnel view, or a view in slight supination with the wrist radially deviated and dorsiflexed.   

Treatment of acute fractures is usually cast immobilization.  If the fracture results into nonunion and is symptomatic, then excision rather than fixation of the fracture fragment is recommended.  Complications such as flexor tendon subluxation, weakness, and rupture have been reported but are rare.

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Metacarpal Shaft Fracture

March 21, 2011 by

Metacarpal Shaft Fracture

History: 25 year old male whose left hand was crushed between 2 football helmets a day prior to presentation.  He complained of pain and swelling and radiographs demonstrated an oblique fracture of the 4th metacarpal shaft. There were no complaints of numbness or tingling. The fracture was displaced dorsally.

Exam:

Left hand demonstrated edema and some ecchymosis. He had active finger motion limited by edema only. Sensation was normal in all fingertips.  All fingers were well-perfused. There was no malrotation noted of the ring finger in flexion. The skin was intact.

PRE-OP XRAY

Treatment options:

Treatment may be accomplished by cast fixation or operative treatment.  In this case operative treatment was chosen in order to ensure anatomical alignment of the fragments, and at the same time allow for early range of motion exercises.  Fingers tend to rapidly loose range of motion when immobilized for prolonged periods of time.  Operative treatment allows for rigid internal fixation by placing 3 lag screws perpendicularly across the fracture.  This patient was allowed active finger and wrist range of motion at 1 week post-op.  The result was no loss of finger or wrist, while the fracture healed in anatomical alignment. 

POST-OP XRAY

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Trapeziectomy with Ligament Reconstruction and Tendon Interposition (LRTI)

November 7, 2010 by

History:  This is a 55-year-old, ambidextrous female who runs her own company.  She has had 10 years of pain in her right thumb base.  The pain has been getting worse over the past 1 year.  She has intermittent symptoms, lasting about 2 or 3 weeks at a time.  She has increased pain with grasping, such as opening jars.  Her symptoms are also interfering with her work.  She is a previous smoker, who quit in 1983.  Previous treatments include:

  • Thumb spica brace
  • Steroid injections

Exam:

Right thumb:  Skin is intact.  There is squaring at the thumb base, also called a “shoulder sign.”  There is a bony prominence on the trapezium.  She has an adduction contracture, but no significant metacarpophalangeal joint hyperextension.  She has tenderness at the carpometacarpal joint with a positive grind test.

Lateral, oblique  and Robert’s views of her right thumb are shown.  She has marked narrowing of the carpometacarpal joint with bone-on-bone contact.  The subchondral bone is sclerotic and there is a small subchondral cyst radially in the trapezium.  She has large osteophytes, >2mm in size.  There is minimal subluxation.  The scaphotrapeziotrapezoid joint does not appear involved.  She is Eaton stage 3 (osteophytes >2mm with no STT joint involvement).

Tests:  Preoperative evaluation was normal.

Options:  She has activity limiting symptoms and has already had a trial of injections and bracing.  While hand therapy, anti-inflammatory medications, heat, ice, and creams and rubs can help with symptoms, she has poor symptom control with bracing and injections and is at a point where surgery can be helpful.  Surgical possibilities include:

  • Simple trapeziectomy—Most surgeons do not choose this option because of a concern that the thumb will settle, however, it can be just as effective as other procedures.
  • Trapeziectomy and ligament reconstruction—This requires a small, but well-anchored tendon graft, typically using all or part of the flexor carpi radialis tendon.
  • Trapeziectomy and tendon interposition arthroplasty—This may use any of a number of tendon grafts that is rolled and placed into the space where the bone was removed.
  • Trapeziectomy with ligament reconstruction and tendon interposition (LRTI)—This is arguably the most common procedure performed, repositioning and suspending the thumb.
  • Implant arthroplasty—Most of these devices are experimental.  Some implants, such as Orthosphere and Swanson silicone spacers, have had disastrous failures.
  • Artelon spacer—This bioabsorbable material is designed to spare bone in lower grades of arthritis.  Early experience suggests good results, but some have reported inflammatory reactions to the material.
  • Arthroscopy with hemiresection and interposition—This is being done in lower grades of arthritis.  Early results are promising.  It is technically challenging to get an arthoscope in this small joint.
  • Consideration can also be made for releasing the adduction contracture and correcting the metacarpophalangeal joint hyperextension, but she has minimal secondary deformity.

Treatment:  She underwent a ligament reconstruction and tendon interposition (LRTI).  She was in a splint until suture removal at about 10 days after surgery.  She then wore a cast for an additional 4 weeks.  She was transitioned to a brace and started hand therapy about 6 weeks after surgery.

Lateral, oblique and Robert’s views of her right thumb are shown.  There are a few specks of trapezium visible in the soft tissues.  There is a wide space between the scaphoid and thumb metacarpal, indicating a good soft tissue suspension of the thumb.

Outcome:  3 months after surgery, she was back to full duties at work and her pain was much improved compared to before surgery.  She was quite pleased with her results.

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