Hook of Hamate Fracture in a Collegiate Baseball Player: A Case Report

Case Diagnosis: Occult Hook of Hamate Fracture

Case Description or Program Description: Patient is a 21-year old male who developed acute left wrist pain after making swing contact with a baseball and bat. Physical exam revealed swelling over the ulnar-sided palmar wrist, tenderness in the hamate/triquetrum region, negative TFCC grind test, and positive hook of hamate pull test. A five-view X-ray of the wrist, including carpal tunnel view, was unremarkable. He was placed in a neutral wrist splint and started occupational therapy. One-week follow-up demonstrated slight improvement of pain and range of motion, and he continued bracing and conservative care for another week. He was unable to return to full practice due to persistent pain and inability to tolerate swinging a full-sized bat. An MRI was ordered to evaluate the wrist due to his lack of injury progression.

Setting: Outpatient Sports Medicine Clinic

Assessment/Results: MRI of the left wrist demonstrated decreased T1, increased T2 signal throughout the hamate involving the neck, indicating a nondisplaced hook of hamate fracture. The patient was placed in an ulnar gutter splint and referred to hand orthopedics for further evaluation and treatment.

Discussion (relevance): This is a case of an occult hook of hamate fracture, which accounts for only 2–4% of carpal fractures and is often missed or diagnosed late. X-rays have a high false-negative rate and may be only 40% sensitive. MRI and CT are superior to X-rays for detecting fractures. This type of fracture also has a high rate of nonunion, occurring in up to 50% of cases, and therefore often requires a surgical referral.

Conclusions: Providers evaluating patients with persistent wrist pain and an exam suspicious for a hook of hamate fracture should ensure frequent follow-up and consider advanced imaging to rule out occult fractures.