Spontaneous Osteonecrosis of the Knee

Abstract

A 69-year-old man was referred to physical therapy by his primary care physician for an insidious onset of right medial knee pain that had been present for over 4 weeks. Due to the disproportionate response following initial management, he was referred to an orthopaedist for imaging. Magnetic resonance imaging revealed medial femoral condyle osteopenia, bone marrow edema, and subchondral bone collapse, and subsequently the patient was diagnosed with spontaneous osteonecrosis of the knee. J Orthop Sports Phys Ther 2018;48(10):824. doi:10.2519/jospt.2018.7923

Spontaneous Osteonecrosis of the Knee: a Systematic Review of Conservative Treatment Approaches

“…In this regard, Geijer et al [29] reported the course of a lesion the healing of which took over 2.5 years. By contrast, clinical symptoms often improved signi cantly after 2 to 6 weeks [13,21,22,25,29,30,33]. A complete disappearance of symptoms was described at the earliest after 2 to 3 months of continuous therapy [7,13,17].…”

“…The MRI-based criteria used for the differential diagnosis of SONK were found to be heterogeneous. While some authors screened images for speci c features, such as focal hypointense areas on T1-or T2-weighted images, visible fracture lines or focal epiphyseal contour depressions [7,[13][14][15][16][17][18][19][20][21][22][23][24], others diagnosed SONK in the presence of bone marrow edema (BME) accompanying typical symptoms [25][26][27]. Two case reports radiologically demonstrated the primary overlay of fracture lines by BME [28,29].…”

“…Sixteen of the twenty-two included studies (73%) reported positive clinical and/or radiological outcomes [7,13,17,[20][21][22][23][25][26][27][28][29][30][31][32][33]. Although RWB was the most thoroughly tested treatment modality, it has also been challenged by some authors.…”

“…Although RWB was the most thoroughly tested treatment modality, it has also been challenged by some authors. While four studies reported only moderate to poor results [14][15][16]24], nine observed favorable outcomes when testing one of the various forms of RWB [7,17,21,27,32] or a combination of RWB with bisphosphonates [20,25,29,33].…”

“…Given the lack of studies comparing different treatment modalities, evidence-based ranking of their effectiveness is not possible. However, considering the most robust body of evidence in its support, it is recommended to start conservative therapy with RWB assisted by adequate pain management [7,17,20,21,25,27,29,32,33]. Authors, that reported good outcomes with RWB, treated their patients for a mean of 3.3 months [7,20,21,25,27,29,32,33].…”