Andersson Lesion Presenting Itself as Spondylodiscitis and Evolving to Pseudoarthrosis in a Patient with Ankylosing Spondylitis: A Case Report

Case Report

Austin J Orthopade & Rheumatol. 2015;2(1): 1011.

Andersson Lesion Presenting Itself as Spondylodiscitis and Evolving to Pseudoarthrosis in a Patient with Ankylosing Spondylitis: A Case Report

Pen M1, Milcic M1, Krajnc A2, Vogrin M1 and Recnik G1*

1Department of Orthopaedic Surgery, University Medical Centre Maribor, Slovenia

2Department of Traumatology, University Medical Centre Maribor, Slovenia

*Corresponding author: Recnik G, Department of Orthopaedic Surgery, University Medical Centre Maribor, Ljubljanska c. 5, 2000 Maribor, Slovenia,

Received: December 08, 2014; Accepted: March 01, 2015; Published: March 03, 2015


This is a case report of a patient with an advanced stage Andesson lesion presenting itself as a spondylodiscitis which evolved to a full pseudoarthrosis. A 57-year-old Caucasian woman with a known history of ankylosing spondylitis was admitted due to worsening pain in her back and lower limbs that did not respond to conservative treatment. A series of surgical procedures were needed. Although ankylosing spondylitis is a well-known disease, Andersson lesions are not well known nor fully understood. Orthopaedic surgeons must be familiar with the condition in order to make the right diagnosis.

Keywords: Andersson lesion; Ankylosing spondylitis; Discovertebral lesion; Aseptic spondylodiscitis; Spondylodiscitis


AL: Andesson Lesion; AS: Ankylosing Spondylitis; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; CT: Computer Assisted Tomography; MRI: Magnetic Resonance Imaging; NSAID: Non Steroid Anti-Inflammatory Drugs; anti-TNF: anti Tumour Necrosis Factor


Ankylosing spondylitis is an idiopathic inflammatory disorder that primarily affects the sacroiliac joints and the spine. The disease is characterized by the ossification of the spinal ligaments, joints and intervertebral discs. These processes lead to a fused and brittle spine susceptible to fractures. Mechanical forces and inflammation result in focal discal or discovertebral lesions that fail to heal and eventually result in pseudoarthrosis. First described by Andersson in 1937, they are named Andersson lesions [1]. Although well known by the specialist community, AL is relatively rare and awareness of the condition has to be spread.

Case Presentation

A 57-year-old patient with history of HLA B27 positive ankylosing spondylitis under continuous ambulatory management by rheumatologists was admitted to the rheumatology department because of worsening pain in the thoracic spine unresponsive to NSAIDs. In the past she was tested positive on the Mantoux skin test and also had a positive Quantiferon test. X-ray of the thoracic spine showed changes suspicious of inflammation. An MRI scan was performed that showed signs consistent with spondylodiscitis of the Th11–Th12 intervertebral disc (Figure 1). The patient was afebrile the whole time during hospitalization and her blood work was unremarkable for inflammation. The idea arose to start treating her with biopharmaceuticals; however, due to a suspected spondylodiscitis and positive Mantoux and Quantiferon tests, treatment was held off.