Differential Diagnosis for Base of Thumb Pain
Single Most Likely Diagnosis
- Gamekeeper's thumb (Ulnar collateral ligament sprain): This is the most likely diagnosis given the mechanism of injury (hyperextension while setting a ball in volleyball) and the location of the pain (base of the thumb). The initial swelling, bruising, and numbness that resolved, leaving only pain, also support this diagnosis.
Other Likely Diagnoses
- Thumb metacarpophalangeal joint sprain: A sprain to the MP joint of the thumb could also occur from hyperextension, leading to pain and stiffness in the base of the thumb.
- Scaphoid fracture: Although less likely given the absence of persistent numbness or swelling, a scaphoid fracture could still be a possibility, especially if the patient experienced significant trauma to the wrist or thumb during the injury.
- De Quervain's tenosynovitis: This condition, which affects the tendons on the thumb side of the wrist, could be exacerbated by repetitive activities like volleyball and cause pain at the base of the thumb.
Do Not Miss Diagnoses
- Ganglion cyst: Although rare, a ganglion cyst could cause numbness, pain, and swelling at the base of the thumb. If left untreated, it could lead to nerve compression or other complications.
- Osteonecrosis of the scaphoid: This condition, also known as Preiser's disease, could occur after a scaphoid fracture and lead to chronic pain and disability if not properly treated.
Rare Diagnoses
- Hook of hamate fracture: A rare fracture of the hamate bone in the wrist could cause pain and numbness in the thumb and fingers.
- Pisotriquetral joint disorders: Disorders of the pisotriquetral joint, such as arthritis or instability, could cause pain and stiffness at the base of the thumb, although these conditions are relatively rare.