summary Scapulothoracic crepitus, or snapping scapula syndrome, manifests as pain at the scapulothoracic junction with overhead activity. Diagnosis is made clinically with painful crepitus of the scapulothoracic joint with forward flexion and improvement of pain with stabilization of the scapula. Treatment is mainly nonoperative with NSAIDs, scapular strenghthening exercises, postural training and activity modifications. Etiology Pathophysiology predisposing abnormal anatomy 6% of scapulae have some superomedial hooking malunion of scapula or rib fractures history of resection of 1st rib for thoracic outlet syndrome overuse with normal anatomy inflammation from overuse results in chronic inflammation, causing bursal fibrosis, bursitis, snapping bony or soft tissue masses osteochondroma elastofibroma dorsi a benign soft tissue tumor scapular chondrosarcoma Associated conditions Scoliosis, kyphosis scapulothoracic dyskinesis Anatomy Osteology - Scapula spans ribs 2 to 7 three borders (superior, lateral, medial) three angles (superomedial, inferomedial, lateral) no direct bony articulation no true synovial articulation Muscles trapezius serratus anterior subscapularis levator scapulae rhomboids supraspinatus infraspinatus teres minor teres major triceps brachii (long head) biceps brachii coracobracialis deltoid pectoralis minor latissimus dorsi (small slip of origin) omohyoid Ligaments transverse scapular ligament - separates suprascapular artery (above) from suprascapular nerve (below, in suprascapular notch) Blood Supply dorsal scapular artery runs deep to rhomboids and levator 1 to 2 cm medial to scapula Bursae Anatomic infraserratus supraserratus Adventitial (pathologic) near superior or inferior angles inconsistently identified Presentation History presentation ranges from mild discomfort to significant disability trauma and overuse have both been reported Symptoms patient complains of "popping" of scapula painful crepitus with elevation of arm pain relieved with stabilization of scapula Physical exam fixed or postural kyphosis may be present tenderness or fullness of symptomatic bursa ask patient to demonstrate symptomatic motions passive scapulothoracic motion by examiner may also reproduce crepitus scapulothoracic dyskinesis may be present evaluate for winging test muscle strength trapezius serratus rhomboids levator latissimus Imaging Radiographs recommended AP, lateral and axillary findings look for osseous abnormalities CT scan indications osseous lesion on plain radiographs MRI indications soft tissue masses inflamed bursae Studies Diagnostic injections selective injection of local anesthetic and/or corticosteroid to point of maximal tenderness can be diagnostic and therapeutic Differential Cervical pathology can be referred to shoulder girdle Treatment Nonoperative NSAIDs, scapular strengthening exercises, postural training, activity modification indications first line of treatment no mass or aggressive lesion local corticosteroid injections indications second line of treatment Operative bursectomy (open or arthroscopic), resection of osseous lesion, resection of scapular border indications cases refractory to nonoperative treatment outcomes improvement in symptoms reported with both open and arthroscopic better results in patients who responded well to injection incomplete resolution of symptoms common despite improvement better results with addition of partial scapulectomy (vs bursectomy alone) Techniques Open position prone, extremity draped free approach vertical incision over medial border of scapula, centered on symptomatic bursa trapezius split in line with fibers rhomboids and levator elevated subperiosteally technique bursa excised angle of scapula can be excised detached muscles repaired through drill holes postoperative care sling immediate post op must protect repaired muscle attachments immobilize x 4 weeks active motion at 8 weeks strengthening at 12 weeks pros and cons pros: wide exposure cons: morbid Arthroscopic position prone, extremity draped free, arm in maximum internal rotation with hand over lumbar spine approach portals: 3 cm medial to medial border of scapula (avoids dorsal scapular nerve and vessels) and below scapular spine (avoids spinal accessory nerve) superior (Bell's) portal: junction of medial one third and lateral two thirds of superior border of scapula trochar as parallel to chest wall as possible technique skeletonize superomedial angle with cautery resect superomedial angle if desired using burr can place spinal needle at superior scapular border to mark lateral limit of resection postoperative care sling immediate post op used for comfort x 1 week active motion and strengthening based on tolerance pros and cons pros: no muscle detachment cons: technically demanding Complications Neurovascular injury suprascapular nerve and vessels dorsal scapular nerve and vessels spinal accessory nerve Chest wall penetration pneumothorax