Diagnosis: Myotonia or Dupuytren's Contracture
The patient's inability to open a closed fist suggests either myotonia (delayed muscle relaxation after contraction) or Dupuytren's contracture (progressive palmar fascial fibrosis causing finger flexion contractures), with the former being more likely if the difficulty is immediate and temporary, and the latter if there is progressive, fixed flexion deformity.
Key Diagnostic Features to Distinguish
Myotonia (Grip Myotonia)
- Immediate difficulty releasing grip after forceful hand closure that improves with repeated attempts (warm-up phenomenon) 1
- Patient cannot voluntarily release contracted muscles for several seconds
- Typically bilateral and symmetric
- Associated with muscle stiffness, particularly in cold weather
- No visible palmar nodules or cords
Dupuytren's Contracture
- Progressive, painless flexion contracture primarily affecting the ring and little fingers 2, 3
- Palpable nodules or cords in the palmar fascia 2
- Gradual onset over months to years, not immediate after grip closure 3
- Most common in men over age 60 of Scandinavian, Irish, or eastern European descent 2
- Fixed contracture that does not improve with repeated attempts
Treatment Approach
For Myotonia
- Referral to neurology for electromyography and genetic testing to confirm diagnosis and identify specific channelopathy 1
- Muscle relaxation improves with repeated contractions (no specific hand therapy needed initially) 1
- Pharmacologic management with sodium channel blockers (mexiletine) or other antimyotonic agents as directed by neurology
For Dupuytren's Contracture
Surgical intervention is indicated when metacarpophalangeal or proximal interphalangeal joint contracture exceeds 30 degrees 2
Non-surgical Options (for contractures <30 degrees):
- Collagenase injections (effective for early stages but high recurrence rates) 3
- Needle aponeurotomy (minimally invasive but high recurrence) 3
Surgical Options (for contractures ≥30 degrees):
- Limited or radical fasciectomy using volar zigzag Brunner incision provides reliable exposure and predictable healing 2
- Full-thickness skin grafts may be considered for patients with Dupuytren's diathesis (early recurrence risk) 2
Post-operative Management:
- Early active-flexion range-of-motion exercises to restore grip strength 2
- Nighttime extension splint for several months postoperatively to maintain correction 2
- Considerable postoperative therapy commitment required 2
Critical Pitfalls to Avoid
- Do not assume all hand contractures are Dupuytren's—myotonia presents with transient grip difficulty, not fixed contracture 1, 2
- Do not delay surgical referral when contracture exceeds 30 degrees, as outcomes worsen with progressive deformity 2
- Recognize that Dupuytren's has high recurrence rates (particularly in younger patients with bilateral disease and family history), requiring long-term follow-up 3
- Spasticity from upper motor neuron lesions (stroke, brain trauma, spinal cord injury) can also cause contractures but presents with increased muscle tone, hyperactive reflexes, and possible clonus 1