Introduction Two distinct entities including Secondary osteonecrosis of the knee Spontaneous osteonecrosis of the knee (this topic) Epidemiology demographics most common in middle age and elderly affects females (>55yo) more frequently than males location 99% of patients have only one joint involved usually epiphysis of medial femoral condyle Pathophysiology may represent a subchondral insufficiency fracture also believed to be caused by a meniscal root tear Presentation Symptoms sudden onset of severe knee pain effusion limited range of motion secondary to pain tenderness over medial femoral condyle Imaging Radiographs recommended views standing AP and lateral of hip, knee and ankle MRI most useful study is helpful to confirm the diagnosis and assist in determining the extent of disease helping guide treatment considerations lesion is crescent shaped Differential Must differentiate from osteochondritis dissecans more common on lateral aspect of medial femoral condyle in adolescent males transient osteoporosis more common in young to middle age men bone bruises and occult fractures associated trauma, bone fragility or overuse idiopathic osteonecrosis of the knee lesion is not crescent shaped Treatment Nonoperative NSAIDs, narcotics, protected weight bearing indications mainstay of treatment as most cases resolve technique physical therapy directed at quadriceps strengthening outcomes initial conservative measure and has shown good results Operative arthroplasty indications when symptoms fail to respond to conservative treatment outcomes successful results reported with TKA (larger lesions or bone collapse) and UKA (smaller lesions) when properly indicated high tibial osteotomy indications when angular malalignment present
QUESTIONS 1 of 3 1 2 3 Previous Next This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE07HK.17) A 74-year-old woman has had acute medial right knee pain for the past 3 months. She denies any history of trauma or previous problems. Coronal and sagittal MRI scans are shown in Figures 11a and 11b. What is the most likely diagnosis? Review Topic QID: 5977 FIGURES: A B 1 Osteoarthritis 11% (16/146) 2 Rheumatoid arthritis 1% (1/146) 3 Medial meniscal tear 11% (16/146) 4 Osteonecrosis 70% (102/146) 5 Transient osteoporosis 8% (11/146) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 4 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.99) A 59-year-old female librarian complains of progressively worsening left knee pain over the last 4 months. She does not recall any traumatic injury to the knee. Physical exam is noteable for tenderness isolated to the medial joint line. She has full ROM and no instability of the knee. Radiographs and MRI image are provided in figures A,B, and C. Which of the following is the best management? Review Topic QID: 485 FIGURES: A B C 1 Open biopsy 1% (32/2281) 2 Chest CT and bone scan 2% (42/2281) 3 Osteochondral autograft transfer 21% (481/2281) 4 Unicompartmental knee arthroplasty 72% (1646/2281) 5 Valgus-producing high tibial osteotomy 3% (69/2281) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 4
osteonecrosis lateral femoral condyle right knee (C2165) Dimitris Zikos Knee & Sports - Spontaneous Osteonecrosis of the Knee (SONK) 3/2/2015 244 1 15 Transient Osteoporosis of the Knee / AVN Femoral Condyle (C1803) Dimitrios Konstantis Knee & Sports - Spontaneous Osteonecrosis of the Knee (SONK) 2/27/2014 90 2 4 Osteochondritis of the Knee? (C1390) Dimitrios Konstantis Knee & Sports - Spontaneous Osteonecrosis of the Knee (SONK) 1/18/2013 219 2 10