Introduction A condition caused by interruption of blood supply to humeral head Pathophysiology pathoanatomy decreased blood supply to humeral head leading to death of cells in bony matrix. bone is resorbed and remodeled, causing subchondral bone collapse and may lead to joint incongruity and arthritic changes etiology similar to hip Remember ASEPTIC mneumonic Alcohol, AIDS Steroids (most common), Sickle, SLE Erlenmeyer flask (Gaucher’s) Pancreatitis Trauma Idiopathic/ Infection Caisson’s (the bends) may be atraumatic posttraumatic four-part fracture-dislocations approach 100% AVN displaced four-part fractures ~45% AVN valgus impacted four-part ~11% AVN three-part ~14% AVN Prognosis related to stage of disease Anatomy Blood supply Humeral head ascending branch of anterior humeral circumflex artery and arcuate artery provides blood supply to humeral head vessel runs parallel to lateral aspect of tendon of long head of biceps in the bicipital groove beware not to injure when plating proximal humerus fractures arcuate artery is the interosseous continuation of ascending branch of anterior humeral circumflex artery and penetrates the bone of the humeral head provides 35% of blood supply to humeral head posterior humeral circumflex artery most current literature supports this as providing the main blood supply to humeral head provides 65% of blood supply Classification Cruess Classification (stages) Stage I Normal x-ray. Changes on MRI. Core decompression. Stage II Sclerosis (wedged, mottled), osteopenia. Core decompression. Stage III Crescent sign indicating a subchondral fracture. Resurfacing or hemiarthroplasty. Stage IV Flattening and collapse. Resurfacing or hemiarthroplasty. Stage V Degenerative changes extend to glenoid. TSA. Presentation Symptoms insidious onset of shoulder pain often without a clear inciting event pain, loss of motion, crepitus, and weakness Physical exam limited range of motion crepitus weakness of the rotator cuff and deltoid muscles Imaging Radiographs recommended views five views of shoulder (shown best in neutral rotation AP) findings no findings on radiograph at onset of disease process osteolytic lesion develops on radiograph demonstrating resorption of subchondral necrosis most common initial site is superior middle portion of humeral head crescent sign demonstrates subchondral collapse may progress to depression of articular surface and consequent arthritic changes. MRI preferred imaging modality ~100% sensitivity in detection will demonstrate edema at the site of subchondral sclerosis Treatment Nonoperative pain medications, activity modification, physical therapy indications first line of treatment technique physical therapy restrict overhead activity and manual labor Operative core decompression + arthroscopy (confirm integrity of cartilage) indications early disease (precollapse Cruess Stage I and II) humeral head resurfacing indications Stage III disease with focal chondral defects, and sufficient remaining epiphyseal bone stock for fixation. hemiarthroplasty indications moderate disease (Cruess Stage III and IV) total shoulder arthroplasty indications advance stage (Cruess V)
QUESTIONS 1 of 4 1 2 3 4 Previous Next (OBQ13.174) A 45-year-old man complains of chronic right shoulder pain. He has a history of chronic steroid use because of asthma. He recently completed a course of physical therapy and has given up his job as a laborer in favor of a desk job. Examination reveals diminished shoulder abduction strength. A radiograph of his shoulder is shown in Figure A. Which of the following surgical treatment options (Figures B through F) is the most appropriate? Review Topic | Tested Concept QID: 4809 FIGURES: A B C D E F Type & Select Correct Answer 1 Figure B 66% (3466/5219) 2 Figure C 15% (781/5219) 3 Figure D 4% (233/5219) 4 Figure E 9% (492/5219) 5 Figure F 4% (187/5219) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (OBQ11.78) A 66-year-old male presents with a three-month history of increasing right shoulder pain. He denies any trauma or prior shoulder problems, and has good rotator cuff strength. His medical history is significant for Crohn's disease which is controlled medically with prednisone therapy during flares. A current MRI image of his shoulder is shown in Figure A. What is the most likely diagnosis? Review Topic | Tested Concept QID: 3501 FIGURES: A Type & Select Correct Answer 1 Gaucher disease 0% (13/3694) 2 Osteoarthritis 0% (15/3694) 3 Chronic rotator cuff tendinopathy 3% (93/3694) 4 Osteonecrosis 95% (3507/3694) 5 Calcific tendinitis 1% (49/3694) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ10.10) A 37-year-old severe asthmatic has been taking daily corticosteroids for twenty years and now reports 4 months of worsening left shoulder pain. He is unable to complete a full day of work due to the pain. A radiograph is provided in Figure A. Which of the following describes the pathogenesis behind this disease process? Review Topic | Tested Concept QID: 3098 FIGURES: A Type & Select Correct Answer 1 Cell-mediated immune response inciting synovial hypertrophy and mononuclear destruction of cartilage 2% (85/4162) 2 Humoral immune response following a systemic infection in an HLA-B27 positive individual 0% (19/4162) 3 Hyperuricemia induced crystalline deposition within the synovial fluid 0% (15/4162) 4 Cellular death of the subchondral bone following an interruption in the vascular supply 96% (4010/4162) 5 Bacterial seeding of the joint inducing polymorphonuclear cell destruction of the cartilage 0% (6/4162) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (0) Podcasts (1) Shoulder & Elbow⎪Avascular Necrosis of the Shoulder Orthobullets Team Shoulder & Elbow - Avascular Necrosis of the Shoulder Listen Now 10:11 min 1/31/2020 77 plays (1)