Orthopedic Viva Exam Guide: Carpal Tunnel Syndrome & Wrist Pathology
Key Takeaway
Orthopedic diagnosis of Carpal Tunnel Syndrome involves assessing clinical symptoms like median nerve distribution numbness and tingling. Key diagnostic tests include Phalen's, Tinel's sign, and the Carpal Compression Test. Electromyography and nerve conduction studies confirm the diagnosis, quantify severity, and help differentiate from other wrist pathologies, guiding appropriate management strategies.
A 29-year-old G1 P0 woman at 28 weeks gestation presents with bilateral hand numbness and nocturnal paresthesias. You suspect carpal tunnel syndrome (CTS). How do you differentiate this from other pathologies, and what is your preferred clinical examination test for this condition?
Candidate: I would take a thorough history to rule out cervical radiculopathy. On physical exam, I would look for thenar wasting and test sensation. I prefer the Durkan test because it is more sensitive and specific than Phalen’s test.
Failing to mention the "nocturnal" nature of the symptoms, or neglecting to discuss differential diagnoses (e.g., cervical spine, double crush). Many candidates also confuse the sensitivity of provocative tests, failing to quantify the Durkan test's superiority.
I would perform a structured clinical assessment to confirm median nerve compression at the carpal tunnel, differentiating it from cervical radiculopathy (checking Spurling’s sign) or proximal nerve entrapment. I prefer the Durkan’s Carpal Compression Test—applying direct pressure over the carpal tunnel for 30 seconds. It is the most sensitive and specific clinical test, with a sensitivity of approximately 90%, outperforming the Phalen’s (wrist flexion) or Tinel’s tests.
You confirm a diagnosis of pregnancy-induced CTS. The patient is distressed by the symptoms. What is the incidence of this condition in the pregnant population, and how do you counsel the patient regarding management?
Candidate: It occurs in about 25% of pregnancies. I would tell the patient it usually goes away after the baby is born. I would advise splinting at night.
Providing only a vague management plan. A high-scoring candidate must emphasize the physiological etiology (fluid retention/edema) and provide a stratified management plan starting with non-operative measures.
The incidence is approximately 25%. The pathophysiology is primarily related to fluid retention and systemic edema. My management is strictly conservative: patient education, nocturnal neutral-position wrist splinting, and symptom monitoring. I reassure the patient that symptoms are generally transient and typically resolve post-partum. Surgical intervention is rarely indicated and reserved only for progressive neurologic deficit or intractable pain, and can be performed safely with appropriate anesthetic precautions if essential.
