Differential Diagnosis for a 39-year-old female with a laceration to the dorsal aspect of her left first knuckle
- The patient's symptoms of pain when trying to flex or extend her finger and possible tendon involvement are crucial in determining the differential diagnosis.
Single most likely diagnosis
- Extensor Tendon Laceration: This is the most likely diagnosis due to the location of the laceration on the dorsal aspect of the first knuckle, which is where the extensor tendons are located. The patient's symptoms of pain when trying to flex or extend her finger also support this diagnosis.
Other Likely diagnoses
- Finger Fracture: A fracture of the finger could also cause pain and limited mobility, especially if the fracture involves the joint or the area where the tendon attaches.
- Infection or Abscess: If the laceration becomes infected, it could cause pain, swelling, and limited mobility of the finger.
- Nerve Damage: Damage to the nerves in the finger could cause pain, numbness, and limited mobility.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Septic Arthritis: Although less likely, septic arthritis is a serious condition that requires prompt treatment. If the laceration becomes infected and the infection spreads to the joint, it could cause septic arthritis, which is a medical emergency.
- Compartment Syndrome: This is a condition where increased pressure within a confined space in the body can cause damage to the muscles and nerves. Although rare, it is a serious condition that requires prompt treatment.
Rare diagnoses
- Tumor or Cyst: A tumor or cyst on the tendon or joint could cause pain and limited mobility, but this is a rare diagnosis and would likely require further imaging and diagnostic testing to confirm.
- Ganglion Cyst: A ganglion cyst is a non-cancerous lump that can develop on the tendon or joint, causing pain and limited mobility. However, this is a rare diagnosis and would likely require further imaging and diagnostic testing to confirm.
Next Steps:
- Evaluate the patient's neurovascular status to ensure that there is no nerve damage or compromised blood flow to the finger.
- Clean and dress the wound to prevent further trauma and infection.
- Order imaging studies (e.g. X-rays) to rule out a fracture.
- Consider ordering an MRI or ultrasound to evaluate the tendon and joint.
- Provide pain management and consider referring the patient to a hand specialist or orthopedic surgeon for further evaluation and treatment.