Population Covered By The Guidance
This pathway provides guidance for imaging patients with suspected avascular necrosis of the hip.
Lead Researcher: Kieran Kusel
Experts & Contributors: Ravinder Dhillon, Eamon Koh, Michael Mason
Date reviewed: April 2019
Date Published: December 2025
Avascular Necrosis of the Left Femoral Head
Avascular Necrosis of the Left Femoral Head
Avascular Necrosis of Bilateral Femoral Heads
Avascular Necrosis of the Femoral Head
- Avascular necrosis of the femoral head (AVN) is the pathologic death of bone and marrow cells resulting from an interruption to their blood supply.
- This can result in collapse and deformation of the femur which can lead to secondary osteoarthritis, loss of hip function and reduced quality of life.
- AVN can be non-traumatic or occur following trauma.
- Plain radiography is usually the initial imaging performed, however, it has a low sensitivity for detecting AVN, particularly in its early stages.
- MRI is the most accurate imaging modality for detecting early AVN and should be performed when there is a high clinical suspicion.
- Bone scintigraphy or CT can be helpful if MRI is unavailable or contraindicated.
- Most patients will ultimately require hip arthroplasty.
- Early diagnosis and treatment is useful to delay the need for joint replacement, particularly because non-traumatic AVN typically occurs in people aged between 30-50 years.
Date of literature search: April 2019
References are graded from Level I to V according to the Oxford Centre for Evidence-Based Medicine, Levels of Evidence. Download the document
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2. Murphey MD, Roberts CC, Bencardino JT, Appel M, Arnold E, Chang EY, et al. ACR Appropriateness Criteria Osteonecrosis of the Hip. J Am Coll Radiol. 2016;13(2):147-55 (Clinical guidelines). https://www.ncbi.nlm.nih.gov/pubmed/26846390
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7. Babis GC, Sakellariou V, Parvizi J, Soucacos P. Osteonecrosis of the femoral head. Orthopedics. 2011;34(1):39 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/21210589
8. Amanatullah DF, Strauss EJ, Di Cesare PE. Current management options for osteonecrosis of the femoral head: part 1, diagnosis and nonoperative management. Am J Orthop (Belle Mead NJ). 2011;40(9):E186-92 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/22022684
9. Guerado E, Caso E. The physiopathology of avascular necrosis of the femoral head: an update. Injury. 2016;47 Suppl 6:S16-s26 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/28040082
10. Assouline-Dayan Y, Chang C, Greenspan A, Shoenfeld Y, Gershwin ME. Pathogenesis and natural history of osteonecrosis. Semin Arthritis Rheum. 2002;32(2):94-124 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/12430099
11. Fukushima W, Fujioka M, Kubo T, Tamakoshi A, Nagai M, Hirota Y. Nationwide epidemiologic survey of idiopathic osteonecrosis of the femoral head. Clin Orthop Relat Res. 2010;468(10):2715-24 (Level IV evidence). https://www.ncbi.nlm.nih.gov/pubmed/20224959
12. Mont MA, Cherian JJ, Sierra RJ, Jones LC, Lieberman JR. Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today? A Ten-Year Update. J Bone Joint Surg Am. 2015;97(19):1604-27 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/26446969
13. Lee GC, Steinberg ME. Are we evaluating osteonecrosis adequately? Int Orthop. 2012;36(12):2433-9 (Level II evidence). https://www.ncbi.nlm.nih.gov/pubmed/23011722
14. Lee MS, Hsieh PH, Shih CH, Wang CJ. Non-traumatic osteonecrosis of the femoral head - from clinical to bench. Chang Gung Med J. 2010;33(4):351-60 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/20804664
15. Ando W, Yamamoto K, Koyama T, Hashimoto Y, Tsujimoto T, Ohzono K. Radiologic and Clinical Features of Misdiagnosed Idiopathic Osteonecrosis of the Femoral Head. Orthopedics. 2017;40(1):e117-e23 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/27755641
16. Di Benedetto P, Niccoli G, Beltrame A, Gisonni R, Cainero V, Causero A. Histopathological aspects and staging systems in non-traumatic femoral head osteonecrosis: an overview of the literature. Acta Biomed. 2016;87 Suppl 1:15-24 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/27104316
17. Meier R, Kraus TM, Schaeffeler C, Torka S, Schlitter AM, Specht K, et al. Bone marrow oedema on MR imaging indicates ARCO stage 3 disease in patients with AVN of the femoral head. Eur Radiol. 2014;24(9):2271-8 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/24863885
18. Lee GC, Khoury V, Steinberg D, Kim W, Dalinka M, Steinberg M. How do radiologists evaluate osteonecrosis? Skeletal Radiol. 2014;43(5):607-14 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/24492890
19. Steinberg ME, Hayken GD, Steinberg DR. A quantitative system for staging avascular necrosis. J Bone Joint Surg Br. 1995;77(1):34-41 (Level II/III evidence). https://www.ncbi.nlm.nih.gov/pubmed/7822393
20. Stoica Z, Dumitrescu D, Popescu M, Gheonea I, Gabor M, Bogdan N. Imaging of avascular necrosis of femoral head: familiar methods and newer trends. Current health sciences journal. 2009;35(1):23-8 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/24778812 https://www.ncbi.nlm.nih.gov/pmc/PMC3945237/
21. Lau RL, Perruccio AV, Evans HM, Mahomed SR, Mahomed NN, Gandhi R. Stem cell therapy for the treatment of early stage avascular necrosis of the femoral head: a systematic review. BMC Musculoskelet Disord. 2014;15:156 (Level I evidence). https://www.ncbi.nlm.nih.gov/pubmed/24886648
22. Amanatullah DF, Strauss EJ, Di Cesare PE. Current management options for osteonecrosis of the femoral head: part II, operative management. Am J Orthop (Belle Mead NJ). 2011;40(10):E216-25 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/22263205
23. Mont MA, Zywiel MG, Marker DR, McGrath MS, Delanois RE. The natural history of untreated asymptomatic osteonecrosis of the femoral head: a systematic literature review. J Bone Joint Surg Am. 2010;92(12):2165-70 (Level I evidence). https://www.ncbi.nlm.nih.gov/pubmed/20844158
24. Zhao FC, Hu HX, Zheng X, Cang DW, Liu X, Zhang JZ, et al. Clinical analysis of 23 cases of steroid-associated osteonecrosis of the femoral head with normal initial magnetic resonance imaging presentation. Medicine (Baltimore). 2017;96(49):e8834 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/29245246
25. Guideline for Diagnostic and Treatment of Osteonecrosis of the Femoral Head. Orthop Surg. 2015;7(3):200-7 (Clinical guidelines). https://www.ncbi.nlm.nih.gov/pubmed/26311093
26. Mitchell MD, Kundel HL, Steinberg ME, Kressel HY, Alavi A, Axel L. Avascular necrosis of the hip: comparison of MR, CT, and scintigraphy. AJR Am J Roentgenol. 1986;147(1):67-71 (Level II/III evidence). https://www.ncbi.nlm.nih.gov/pubmed/3487233
27. Karantanas AH, Drakonaki EE. The role of MR imaging in avascular necrosis of the femoral head. Semin Musculoskelet Radiol. 2011;15(3):281-300 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/21644201
28. Roth A, Beckmann J, Bohndorf K, Fischer A, Heiss C, Kenn W, et al. S3-Guideline non-traumatic adult femoral head necrosis. Arch Orthop Trauma Surg. 2016;136(2):165-74 (Clinical guidelines). https://www.ncbi.nlm.nih.gov/pubmed/26667621
29. Yeh LR, Chen CK, Huang YL, Pan HB, Yang CF. Diagnostic performance of MR imaging in the assessment of subchondral fractures in avascular necrosis of the femoral head. Skeletal Radiol. 2009;38(6):559-64 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/19234700
30. Stevens K, Tao C, Lee SU, Salem N, Vandevenne J, Cheng C, et al. Subchondral fractures in osteonecrosis of the femoral head: comparison of radiography, CT, and MR imaging. AJR Am J Roentgenol. 2003;180(2):363-8 (Level II/III evidence). https://www.ncbi.nlm.nih.gov/pubmed/12540435
31. Agrawal K, Tripathy SK, Sen RK, Santhosh S, Bhattacharya A. Nuclear medicine imaging in osteonecrosis of hip: Old and current concepts. World journal of orthopedics. 2017;8(10):747-53 (Review article). https://www.ncbi.nlm.nih.gov/pubmed/29094004 https://www.ncbi.nlm.nih.gov/pmc/PMC5656489/
32. Agarwal KK, Mukherjee A, Sharma P, Bal C, Kumar R. Incremental value of 99mTc-MDP hybrid SPECT/CT over planar scintigraphy and SPECT in avascular necrosis of the femoral head. Nucl Med Commun. 2015;36(10):1055-62 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/26308940
33. Luk WH, Au-Yeung AW, Yang MK. Diagnostic value of SPECT versus SPECT/CT in femoral avascular necrosis: preliminary results. Nucl Med Commun. 2010;31(11):958-61 (Level II/III evidence). https://www.ncbi.nlm.nih.gov/pubmed/20717063
34. Fan W, Zhu L, Chen J, Guo C, Yan Z. Identifying Patients Who Will Most Benefit from Single Photon Emission Computerized Tomography and Computerized Tomography After Femoral Neck Fracture. Med Sci Monit. 2017;23:5669-74 (Level III evidence). https://www.ncbi.nlm.nih.gov/pubmed/29182595
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36. Chinese Guideline for the Diagnosis and Treatment of Osteonecrosis of the Femoral Head in Adults. Orthop Surg. 2017;9(1):3-12 (Clinical guidelines). https://www.ncbi.nlm.nih.gov/pubmed/28371498
37. Sun W, Wang BL, Li ZR. Chinese specialist consensus on diagnosis and treatment of osteonecrosis of the femoral head. Orthop Surg. 2011;3(2):131-7 (Clinical guidelines). https://www.ncbi.nlm.nih.gov/pubmed/22009599
Pathway User Guide
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The relative radiation level (RRL) of each imaging investigation is displayed in the pop up box.
| SYMBOL | RRL | EFFECTIVE DOSE RANGE |
|---|---|---|
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None | 0 |
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Minimal | < 1 millisieverts |
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Low | 1-5 mSv |
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Medium | 5-10 mSv |
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High | >10 mSv |
Disclaimer
Status Of Recommendations Each pathway is designed to assist clinicians in situations when faced with a large array of possible diagnostic tests and examinations. However, it is recognised that diagnostic practice may differ from a particular pathway depending on local availability of equipment and expertise, as well as the experience of individual clinicians. Therefore each pathway is neither a rigid set of rules, nor a substitute for clinical assessment, and individual patient circumstances should always be considered.
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Plain Radiography
Initial study of choice for suspected AVN. However, plain radiographs have a limited sensitivity for detecting early AVN and, when normal or non-specific changes are seen, further investigations may be necessary. In some centres, MRI is used as the first line imaging modality when there is a high clinical suspicion for AVN.
- The recommended initial imaging study in patients with suspected AVN
- An anteroposterior view of the pelvis and frog-leg lateral view of the hip should be performed
- Relatively inexpensive and widely available
- Radiographic findings in AVN may be normal, abnormal or equivocal
- Identification of characteristic features (e.g. crescent sign) and detection of articular collapse, or demonstration of alternative diagnosis on radiographs may obviate the need for further imaging
- However, given the low sensitivity for detecting early stage disease (as low as 41%), when plain radiographs are negative or equivocal further imaging is often required
- In some centres, plain radiographs are not performed and MRI is used as the first line imaging modality when there is a high clinical suspicion for AVN
Magnetic Resonance Imaging (MRI)
Most accurate imaging modality for detection and staging of suspected AVN. In some centres, MRI is used as the first line imaging modality when there is a high clinical suspicion for AVN.
- Currently the most accurate imaging modality to detect early AVN
- If there is a strong clinical suspicion, MRI of both hips should be performed even if plain radiographs are normal
- A systematic review of 43 studies found that MRI has an overall sensitivity of 93% and specificity of 91% for detecting early AVN, higher than other imaging modalities available
- MRI demonstrates signal changes associated with osteocyte death and marrow fat cell replacement in early disease. It allows assessment of lesion stage, size and location which can help direct treatment and estimate prognosis
- MRI can also demonstrate alternate pathology which may be contributing to the patient’s symptoms.
- Routine MR imaging has limited sensitivity for the detection of subchondral fractures. When there is concern for a subchondral fracture, CT is recommended
Bone Scintigraphy
More sensitive than plain radiographs for detecting AVN; however, it has a lower sensitivity than MRI for detecting early AVN. Useful in more advanced disease and is particularly helpful to identify subchondral fractures.
- Can detect early stages of AVN when radiographs are negative or inconclusive.
- However, due to its lower spatial resolution, lower sensitivity and specificity, and inability to quantify the lesion, planar bone scintigraphy has largely been replaced by MRI
- Sensitivity of bone scintigraphy varies significantly when comparing different studies (range: 75-91%). This may be because it has a higher sensitivity for detecting AVN in femoral neck fractures due to the sudden and nearly complete cut-off of blood supply, but is less sensitive in detecting AVN in chronic processes such as steroid-induced AVN
- Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) has a higher anatomical resolution, sensitivity and specificity than SPECT as well as planar bone scintigraphy. Results from one study showed:
- A sensitivity of 98% and specificity of 87% for SPECT/CT
- A sensitivity of 75% and specificity of 40% for planar bone scintigraphy
- Bone scintigraphy, particularly SPECT/CT, remains a valid alternative in suspected radiographically occult early AVN when MRI is contraindicated
Computed Tomography (CT)
Superior to plain radiographs but inferior to MRI for the early detection of AVN.
- Higher sensitivity and specificity than plain radiography in overall detection of AVN, however, for early disease the sensitivity of CT is low (55%)
- Although studies have reported CT to be less sensitive than both bone scintigraphy and MRI in detecting early AVN, it has been highlighted that few studies have used modern multi-detector CT scanners. It is argued that the true sensitivity is much higher when current-generation CT scanners are used and therefore CT is likely to play an increasing role in the future
- Current American College of Radiology (ACR) guidelines recommend CT to further evaluate a patient with suspected AVN when radiographs are normal and MRI is contraindicated. It is thought that CT is more specific than bone scintigraphy and allows better anatomic assessment, however, SPECT/CT is more sensitive than CT
- CT scans are more helpful in advanced disease (ARCO stage II and above), and are particularly useful to assess for subchondral fractures when this is not clearly defined on MRI
- CT can determine the extent, severity and location of subchondral lucencies, sclerosis and articular collapse, and can demonstrate early secondary degenerative joint disease. It is a useful investigation to aid with surgical planning