Intramuscular hematoma with motor weakness after trigger point injection

RATIONALE Although trigger point injection is known as an easy and low-risk procedure, it is contraindicated to patients with hemorrhagic disorders or who regularly take anticoagulants/antiplatelets. However, taking clopidogrel is not a defined contraindication to this low-risk procedure. PATIENT CONCERNS The chief complaint of a 76-year old woman regularly taking clopidogrel was low back and left buttock pain which prolonged for several years. DIAGNOSES The patient was diagnosed with L4-5 and L5-S1 spinal stenosis at the orthopedics department and was referred for lumbar spinal epidural steroid injection. INTERVENTION She was treated with trigger point injection. OUTCOMES Three hours after the injection, she complained motor weakness and pain in the injection area. A hematoma on left gluteus medium muscle was detected with ultrasonography and ultrasound-guided needle aspiration was accomplished to relieve the symptom. LESSONS Trigger point injection for patients taking clopidogrel should be done with a caution to prevent such complication.