Undiagnosed Hamate Injury

Abstract 

A 23-year-old right-handed female presented with a 7-month old wrist injury. The injury occurred with a high load end range wrist extension while lifting a patient. MRI report confirmed a TFCC tear of the central portion of the left wrist, as well as a cyst superior to the Scapholunate.

Weightbearing of the affected wrist was significantly decreased although it did not improve significantly with the WristWidget. Her low weight-bearing tolerance AND lack of significant improvement with the WristWidget, as well as NO change in weight-bearing tolerance after one week of wearing the WristWidget, sparked an online evaluation.

Upon evaluation, the patient presented with a positive hook-pull test with pain to touch on the hamate. A positive vibration test to the hamate for ulnar nerve was also recorded. A custom dorsal blocking splint was recommended to treat the hamate injury. Exercise therapy following splinting significantly decreased pain and allowed the patient to regain pre-injury wrist function. 

Introduction 

The wrist largely remains a mysterious black box, requiring special attention to correctly diagnose and treat. Often a sore wrist is diagnosed as ‘sprained’, but this appears to be inaccurate in many cases (Guly, 2002). The Triangular fibrocartilage complex (TFCC) and hamate bone are two structures often presenting with ulnar sided wrist pain after an injury. It is therefore important to differentiate between hamate and TFCC injuries early on to improve treatment outcomes. 

The weight-bearing test can be used to assist in defining these injuries objectively. TFCC tears present with a decreased weight-bearing of the affected wrist, which significantly increases when the TFCC is supported with the WristWidget or non-elastic tape. The weight-bearing test results of a hamate injury will also indicate a decrease but will not respond to the WristWidget. A modified weight-bearing test, along with a hook-pull test, will assist in the correct management of a suspected hamate injury. 

Patient profile:

  • A 23-year-old female patient who is left hand dominant injured her wrist in May of 2019.
  • She follows a vegan diet and does not recall any stomach related problems.
  • She is an active individual and works as a caretaker.

Mechanism of Injury:

A high loaded, end-range wrist extension that occurred during the shifting of an elderly person on to a bed. She reported a popping sensation, and ulnar sided wrist pain that followed. 

Symptoms:

Ulnar sided wrist pain during weight-bearing activities. Pain during gripping activities. Her wrist pain became general, spreading to the radial side

Test Results:

MRI

A central TFCC tear was diagnosed via MRI on the 31st of July 2019, accompanied by a cyst superior to the Scapholunate and a small tear in the Scapholunate.

Weight Bearing Test:

Aug 2019  Weight-bearing test 1 month after injury recorded a 7kg tolerance on the left wrist. This improved to 13kg when the WristWidget was worn but did not increase weekly. 

The Weight-bearing test was modified to allow 4th/5th digit to go off of the scale, removing tension off of the hamate. Her load increased above 13kg, and pain decreased. This was done in March of 2020.

The right wrist appeared to have functional weight-bearing of more than 45 kg, with De Quervain’s syndrome present. 

Blood:

Her medical history includes the following blood tests that were conducted to determine if there were any underlying factors: 

    • (normal results) Anti CCP, CRP, ANA, CBC, LFT, HBA1c, and Electrophoresis. 
    • Rheumatoid Factors - 38 IU/mL (normal <14)

Additional Diagnostic Tests:

High-frequency vibration along ulnar nerve/hamate produced positive signs for symptom aggravation performed in March 2020. A positive hook-pull test for the hamate was recorded during the month of March as well.

Treatments:

  • She received a cortisone injection in her wrist in October 2019 which did not have any long-standing benefit. 
  • She was prescribed Nortriptyline and Naproxen for approximately 1-3 months (also Voltaren and Hirudoid Creams + wrap cling film for de Quervain’s) in January of 2020.

Suspected injury:

Hamate bone bruise

Treatment Plan:

  • Dorsal blocking splint 24/7: interphalangeal’s straight, metaphalangeals at 60 degrees and wrist at 15 degrees extension x 4 weeks. 
  • Measure pain to touch at hamate weekly. 
  • Measure hook pull test pain weekly. 
  • Daily AROM (Active Range of Motion) with no load of wrist, fingers, elbow, shoulder. 

Exercise rehabilitation took place after the 4-week dorsal blocking splint period was completed.

 

Gentle exercises through full wrist range of motion were performed when the pain to touch was eliminated. Gentle strengthening exercises for the Brachioradialis was implemented with a 1kg dumbbell, adjusting volume and load accordingly as progress was made. The protocol strengthened the wrist and forearm musculature isometrically before combining movement and load. She was instructed to record symptoms and decrease exercise load and volume if symptoms returned. These exercises were completed during week 4 to week 8.

She was instructed to implement a general strengthening program at the start of week 9 as symptoms subsided, she was pain-free, and her weight-bearing results returned to baseline. 

 

References 

Guly, H., 2002. Injuries initially misdiagnosed as sprained wrist (Beware the sprained wrist). Emergency Medicine Journal, 19(1), pp.41-42.

Hook of Hamate - Pull Test

Image attribution: CC BY-SA 2.1 jp