Skeletal Radiology

, Volume 48, Issue 12, pp 1961–1974 | Cite as

Subchondral insufficiency fracture of the knee: grading, risk factors, and outcome

  • Samia Sayyid
  • Yara Younan
  • Gulshan Sharma
  • Adam Singer
  • William Morrison
  • Adam Zoga
  • Felix M. GonzalezEmail author
Scientific Article



To propose an magnetic resonance imaging (MRI) grading system for subchondral insufficiency fracture of the knee (SIFK) to predict outcome and assess risk factors.

Materials and methods

A total of 50 SIFK patients were retrospectively reviewed utilizing two MRI examinations approximately a year apart and compared them with 51 control subjects. A grading system was introduced that classifies lesions as low- vs high-grade. Lesion location 3D dimensions, extent of bone marrow edema (BME), location of meniscal tears and associated extrusion, degree of chondrosis and among other parameters were stratified according to lesion grade and compared with follow-up examinations. Statistical analyses were performed (Pearson’s correlation, binary logistic regression, and Chi-squared analysis).


The majority of SIFK lesions were low-grade (LG; 78%) and most of them (70%) were observed in the medial femoral condyle. Predictor variables comparing low-grade and high-grade SIFK lesions included meniscal tear (p = 0.01), degree of extrusion (p < 0.003), chondrosis (p = 0.01), medial chondrosis grade (p = 0.001), medial femoral condyle (p = 0.01), surface collapse (p < 0.0001), marrow edema improvement (p < 0.0001), first MRI anteroposterior dimension (p = 0.001), transverse dimension (p < 0.001), and ellipsoid volume (p = 0.02). Predictor variables found to be significantly different between controls and patients were meniscal tear (p = 0.024), location of the medial meniscal tear (p < 0.0001), degree of extrusion (p < 0.0001), chondrosis (p < 0.0001), joint effusion (p < 0.0001), Baker’s cyst (p < 0.0001), knee lock (p = 0.03) and buckle (p = 0.01), and history of trauma (p = 0.01).


A SIFK grading system for MRI is introduced. Surrogate markers of high-grade lesions include medial meniscus posterior root tears with associated moderate to severe extrusion, high-grade chondrosis, larger lesion sizes (anteroposterior/transverse), and articular surface collapse. Improvement of BME on follow-up was highly predictive of low-grade disease.


Insufficiency fracture of the knee Meniscus Bone marrow edema Chondrosis Spontaneous osteonecrosis of the knee 



Bone marrow edema


Medial meniscal tears at the posterior root attachment


Magnetic resonance imaging


Subchondral insufficiency fracture of the knee


Spontaneous osteonecrosis of the knee



  1. 1.
    Pathria MN, Chung CB, Resnick DL. Acute and stress-related injuries of bone and cartilage: pertinent anatomy, basic biomechanics, and imaging perspective. Radiology. 2016;280(1):21–38.CrossRefGoogle Scholar
  2. 2.
    Ahlbäck S, Bauer GC, Bohne WH. Spontaneous osteonecrosis of the knee. Arthritis Rheum. 1968;11(6):705–33.CrossRefGoogle Scholar
  3. 3.
    Mears SC, McCarthy EF, Jones LC, Hungerford DS, Mont MA. Characterization and pathological characteristics of spontaneous osteonecrosis of the knee. Iowa Orthop J. 2009;29:38–42.PubMedPubMedCentralGoogle Scholar
  4. 4.
    Yasuda T, Ota S, Fujita S, Onishi E, Iwaki K, Yamamoto H. Association between medial meniscus extrusion and spontaneous osteonecrosis of the knee. Int J Rheum Dis. 2018;21(12):2104–11.CrossRefGoogle Scholar
  5. 5.
    Karim AR, Cherian JJ, Jauregui JJ, Pierce T, Mont MA. Osteonecrosis of the knee. Ann Transl Med. 2015;3(1):6.PubMedPubMedCentralGoogle Scholar
  6. 6.
    Lotke PA, Ecker ML. Osteonecrosis of the knee. J Bone Joint Surg Am. 1988;70(3):470–3.CrossRefGoogle Scholar
  7. 7.
    Pape D, Seil R, Fritsch E, Rupp S, Kohn D. Prevalence of spontaneous osteonecrosis of the medial femoral condyle in elderly patients. Knee Surg Sports Traumatol Arthrosc. 2002;10(4):233–40.CrossRefGoogle Scholar
  8. 8.
    Robertson DD, Armfield DR, Towers JD, Irrgang JJ, Maloney WJ, Harner CD. Meniscal root injury and spontaneous osteonecrosis of the knee: an observation. J Bone Joint Surg Br. 2009;91(2):190–5.CrossRefGoogle Scholar
  9. 9.
    Yamagami R, , Taketomi S, Inui H, Tahara K, Tanaka S. The role of medial meniscus posterior root tear and proximal tibial morphology in the development of spontaneous osteonecrosis and osteoarthritis of the knee. Knee. 2017;24(2):390–5.CrossRefGoogle Scholar
  10. 10.
    Wilmot AS, Ruutiainen AT, Bakhru PT, Schweitzer ME, Shabshin N. Subchondral insufficiency fracture of the knee: a recognizable associated soft tissue edema pattern and a similar distribution among men and women. Eur J Radiol. 2016;85(11):2096–103.CrossRefGoogle Scholar
  11. 11.
    Sung JH, Ha JK, Lee DW, Seo WY, Kim JG. Meniscal extrusion and spontaneous osteonecrosis with root tear of medial meniscus: comparison with horizontal tear. Arthroscopy. 2013;29(4):726–32.CrossRefGoogle Scholar
  12. 12.
    International Cartilage Repair Society (ICRS). ICRS Cartilage Injury Evaluation Package. Developed 27–30 January 2000.
  13. 13.
    Aglietti P, Insall JN, Buzzi R, Deschamps G. Idiopathic osteonecrosis of the knee. Aetiology, prognosis and treatment. J Bone Joint Surg Br. 1983;65(5):588–97.CrossRefGoogle Scholar
  14. 14.
    Feldstein A, Elmer PJ, Orwoll E, Herson M, Hillier T. Bone mineral density measurement and treatment for osteoporosis in older individuals with fractures: a gap in evidence-based practice guideline implementation. Arch Intern Med. 2003;163(18):2165–72.CrossRefGoogle Scholar
  15. 15.
    Lotke PA, Abend JA, Ecker ML. The treatment of osteonecrosis of the medial femoral condyle. Clin Orthop Relat Res. 1982;(171):109–16.Google Scholar
  16. 16.
    Norman A, Baker ND. Spontaneous osteonecrosis of the knee and medial meniscal tears. Radiology. 1978;129:653–6. Scholar
  17. 17.
    Yamamoto T, Yamaguchi T, Lee KB, Bullough PG. A clinicopathologic study of osteonecrosis in the osteoarthritic hip. Osteoarthritis Cartilage. 2000;8(4):303–8.CrossRefGoogle Scholar
  18. 18.
    Fujita S, Arai Y, Honjo K, Nakagawa S, Kubo TA. Case of spontaneous osteonecrosis of the knee with early and simultaneous involvement of the medial femoral condyle and medial tibial plateau. Case Rep Orthop. 2016;2016:2574975. Scholar
  19. 19.
    Yamamoto T, Bullough PG. Spontaneous osteonecrosis of the knee: the result of subchondral insufficiency fracture. J Bone Joint Surg Am. 2000;82(6):858–66.CrossRefGoogle Scholar
  20. 20.
    Reddy AS, Frederick RW. Evaluation of the intraosseous and extraosseous blood supply to the distal femoral condyles. Am J Sports Med. 1998;26(3):415–9.CrossRefGoogle Scholar
  21. 21.
    Satku K, Kumar VP, Chong SM, Thambyah A. The natural history of spontaneous osteonecrosis of the medial tibial plateau. J Bone Joint Surg Br. 2003;85(7):983–8.CrossRefGoogle Scholar
  22. 22.
    An VV, Broek MVD, Oussedik S. Subchondral insufficiency fracture in the lateral compartment of the knee in a 64-year-old marathon runner. Knee Surg Relat Res. 2017;29(4):325–8.CrossRefGoogle Scholar
  23. 23.
    Hussain ZB, Chahla J, Mandelbaum BR, Gomoll AH, LaPrade RF. The role of meniscal tears in spontaneous osteonecrosis of the knee: a systematic review of suspected etiology and a call to revisit nomenclature. Am J Sports Med. 2019;47(2):501–7.CrossRefGoogle Scholar
  24. 24.
    Imhof H, Sulzbacher I, Grampp S, Czerny C, Youssefzadeh S, Kainberger F. Subchondral bone and cartilage disease: a rediscovered functional unit. Investig Radiol. 2000;35(10):581–8.CrossRefGoogle Scholar
  25. 25.
    Artul S, Jabaly-Habib H, Artoul F, Habib G. The association between Baker’s cyst and medial meniscal tear in patients with symptomatic knee using ultrasonography. Clin Imaging. 2015;39(4):659–61.CrossRefGoogle Scholar
  26. 26.
    Al-Rowaih A, Lindstrand A, Bjorkengren A, Wingstrand H, Thorngren KG. Osteonecrosis of the knee. Diagnosis and outcome in 40 patients. Acta Orthop Scand. 1991;62(1):19–23.CrossRefGoogle Scholar
  27. 27.
    Ecker ML, Lotke PA. Spontaneous osteonecrosis of the knee. J Am Acad Orthop Surg. 1994;2(3):173–8.CrossRefGoogle Scholar
  28. 28.
    Mont MA, Baumgarten KM, Rifai A, Bluemke DA, Jones LC, Hungerford DS. Atraumatic osteonecrosis of the knee. J Bone Joint Surg Am. 2000;82(9):1279–90.CrossRefGoogle Scholar
  29. 29.
    Marti CB, Rodriguez M, Zanetti M, Romero J. Spontaneous osteonecrosis of the medial compartment of the knee: a MRI follow-up after conservative and operative treatment, preliminary results. Knee Surg Sports Traumatol Arthrosc. 2000;8(2):83–8.CrossRefGoogle Scholar
  30. 30.
    Koshino T, Okamoto R, Takamura K, Tsuchiya K. Arthroscopy in spontaneous osteonecrosis of the knee. Orthop Clin N Am. 1979;10(3):609–18.Google Scholar
  31. 31.
    Forst J, Forst R, Heller KD, Adam G. Spontaneous osteonecrosis of the femoral condyle: causal treatment by early core decompression. Arch Orthop Trauma Surg. 1998;117(1–2):18–22.CrossRefGoogle Scholar
  32. 32.
    Mont MA, Tomek IM, Hungerford DS. Core decompression for avascular necrosis of the distal femur: long term followup. Clin Orthop Relat Res. 1997;(334):124–30.CrossRefGoogle Scholar
  33. 33.
    Valenti Nin JR, Leyes M, Schweitzer D. Spontaneous osteonecrosis of the knee. Treatment and evolution. Knee Surg Sports Traumatol Arthrosc. 1998;6(1):12–5.CrossRefGoogle Scholar
  34. 34.
    Gorbachova T, Melenevsky Y, Cohen M, Cerniglia BW. Osteochondral lesions of the knee: differentiating the most common entities at MRI. Radiographics. 2018;38(5):1478–95.CrossRefGoogle Scholar

Copyright information

© ISS 2019

Authors and Affiliations

  1. 1.Department of Radiology and Imaging SciencesEmory University School of MedicineAtlantaUSA
  2. 2.Department of Radiology and Imaging SciencesUniversity of Massachusetts Medical SchoolWorcesterUSA
  3. 3.University of CalgaryCalgaryCanada
  4. 4.Department of Radiology and Imaging SciencesThomas Jefferson University HospitalPhiladelphiaUSA

Personalised recommendations