Treatment of Muscle Spasm Associated with Fractures
Cyclobenzaprine is the first-line pharmacologic treatment for muscle spasm associated with acute fractures, used as an adjunct to rest and physical therapy for short-term relief (2-3 weeks maximum). 1
Pharmacologic Management
Primary Treatment: Skeletal Muscle Relaxants
Cyclobenzaprine is FDA-approved specifically for relief of muscle spasm associated with acute, painful musculoskeletal conditions, providing relief of muscle spasm and its associated symptoms including pain, tenderness, and limitation of motion 1
The standard dosing is 5-10 mg three times daily, with the 5 mg dose demonstrating statistically significant superiority over placebo for pain relief and functional improvement 1
Treatment duration should be limited to 2-3 weeks because muscle spasm associated with acute painful musculoskeletal conditions is generally of short duration, and adequate evidence for more prolonged use is not available 1
Carisoprodol, orphenadrine, and tizanidine are alternative skeletal muscle relaxants with fair evidence of effectiveness compared to placebo for musculoskeletal conditions, though cyclobenzaprine has been evaluated in the most clinical trials with consistent effectiveness 2
Combination Therapy
The combination of a skeletal muscle relaxant with an NSAID is superior to single agents alone for treating acute musculoskeletal disorders with muscle spasm 3
When combining cyclobenzaprine with naproxen, expect more side effects (primarily drowsiness) than naproxen alone, though the combination is well-tolerated 1
Alternative Pharmacologic Options
Magnesium sulfate (2 g IV) can produce immediate relief of severe, painful muscle spasm in specific cases, though this is based on limited case report evidence 4
Benzodiazepines (such as diazepam) have comparable efficacy to cyclobenzaprine but with different side effect profiles—diazepam causes more dizziness while cyclobenzaprine causes more dry mouth 1
Non-Pharmacologic Management
Early Mobilization and Rehabilitation
Begin range-of-motion exercises within the first postoperative days following fracture treatment, including appropriate joint motion exercises 5, 6
Early fracture stabilization through proper immobilization provides the most effective analgesia and reduces muscle spasm 7
Aggressive physical therapy should be avoided in the immediate postoperative period as it may increase risk of fixation failure, but early gentle mobilization is essential 5
Rehabilitation Timeline
Start physical training and muscle strengthening early in the post-fracture period, followed by long-term balance training and fall prevention 5, 7
For most fractures without muscle entrapment, waiting 4-6 months allows time for resolution of spasm related to orbital edema/hematoma before considering surgical intervention for persistent issues 5
Prolonged immobilization leads to stiffness and muscle atrophy requiring aggressive rehabilitation once discontinued 5
Important Caveats and Pitfalls
Duration Limitations
Do not prescribe skeletal muscle relaxants beyond 2-3 weeks—this is a critical FDA limitation based on lack of evidence for prolonged use 1
Cyclobenzaprine has not been found effective for spasticity associated with cerebral or spinal cord disease, only for acute musculoskeletal conditions 1
Monitoring Requirements
Assess for drowsiness, the most frequent adverse reaction with cyclobenzaprine, which occurs whether or not clinical improvement is achieved 1
In patients with mild hepatic impairment, start with 5 mg dose and titrate slowly; avoid use in moderate to severe hepatic insufficiency 1
Special Clinical Scenarios
In rare cases, severe muscle spasm can cause pathological fractures or fixation failure—early recognition and multidisciplinary management with high-dose benzodiazepines may be required 8
For orbital fractures with muscle entrapment causing oculocardiac reflex (bradycardia, nausea, vomiting), this is life-threatening and requires immediate surgical treatment, not just muscle relaxants 5