How to perform SOR

Halifax Biomedical Inc. has developed a complete Stereo Orthopaedic Radiography (SOR) solution from the operating room, to imaging, to the doctor’s office by providing purpose-built surgical tools and imaging equipment as well as stability assessment services. This provides a chain of processes optimized for ease of use, consistency and accuracy of the data, and minimal impact on work flow.

In the OR

Halifax Bead InserterWhile performing surgery, the surgeon uses the Halifax Bead Inserter to place tiny beads in the bone to act as reference points. A minimum of three, and preferably five or six, of these beads are placed in optimized locations so that they are visible from multiple views. This straight-forward procedure takes 2 to 3 minutes on average and enables surgeons to gather vast amounts of data about a patient down the road. Beads can be placed in almost any bone in the body for monitoring and diagnostic purposes.


SOR ExamPatients are brought back to the clinic for regular follow-up imaging after their surgery. Unlike conventional x-ray, low-dose SOR images are taken at two different angles allowing for three-dimensional stability assessment of the patient’s bone and implants. Halifax Biomedical Inc.’s Halifax Imaging Suite ( or Kit) options use cutting-edge digital imaging equipment to increase precision of measurements while at the same time reducing patient dose. SOR images are transferred to Halifax Biomedical Inc. in an anonymized way so that patient confidentiality is guaranteed.

Stability Assessment

Stability AssessmentThe images are analyzed by expert analysts and the very precise measurements are sent back to the surgeon for interpretation in the form of a detailed report. This stability assessment can be done on hip and knee replacements, as well as ankle, spine, and many other joints, and is performed using Model-Based RSA (RSAcore, Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands). Pre-operative spine measurements are performed with Halifax Biomedical Inc.’s proprietary software.