Project start: 2009
Supervisors: Britt Stuge, PT, phD, Olav Røise, MD, phD, Stephan M Røhrl, MD, phD
The main purpose of this project was to examine the outcome of sacroiliac joint (SIJ) fusion and symphysiodesis in patients' with severe pelvic girdle pain (PGP) after pregnancy and trauma (Paper 1 and 2). The reason for surgery is based on the assumption that the chronic pain is caused by pelvic joint instability. To examine the degree of joint movement during the Active Straight Leg Raise (ASLR) Radiostereomethric analysis (RSA) was used (Paper 4). The accuracy and precision of the RSA method for the pelvis was evaluated by a phantom study (Paper 3).
Question: What is the outcome of sacroiliac fusion for patients with PGP?
Material & Methods: A single subject design study was performed in which totally 20 patients were planned operated with SIJ fusion in two centres, 10 in Norway and and 10 by dr. Sturresson, Ängelholm, Sweden,. A strict protocol was used to evaluate function, pain and health related quality of life (HRQoL) before and after surgery. The patients were examined with specific clinical tests and a CT-guided injection into the SIJ. The patients were followed for 1 year and healing was evaluated by CT. All patients underwent RSA to evaluate movement before and after fusion.
Results: Nine patients have been operated in Norway with 1-year follow-up. Ten patients have been operated in Sweden, but only the Norwegian patients will be presented due to incomplete follow up with missing data. The material will be analysed in the beginning of 2012.
Question: What is the long-term outcome of patients operated with sacroiliac fusion?
Material & Methods: Eight-one patients operated at Kysthospitalet in Hagavik in the period 1977-1991 was identified and 50 of these patients were evaluated by a questionnaire comprised Oswestry disability index (ODI), visual analogue scale (VAS) and SF-36. These patients were compared to 28 non-operated patients with PGP. The short-term outcome was compared to the long-term outcome.
Results: The operated patients reported moderate disability (ODI 37 (95% CI: 31-43)) and pain (VAS 54 (95% CI: 46-63)). The patients had moderate disability, but their mental status was not affected in the same manner. There were no statistically differences between the operated patients and the non-operated group. The subgroup of patients (48%) with a good short-term outcome had a significantly better function and less pain than the patients with a poor short-term result.
Question: Does RSA show the proper accuracy and precision to be used in the measure of 3D SIJ movement and how many RSA markers are needed?
Material and methods: To measure the precision and accuracy a phantom study was performed. To measure precision of the RSA double examination was performed. The mean difference of these examinations represents the precision. The precision was measured in a phantom and in 4 patients. The accuracy was measured with a phantom attached to micrometer. Every movement done by the micrometer was compared to the measured value by the RSA system. Differences between the true value and the measured value represent the accuracy.
Results: RSA is a good method to measure movement in the SIJ. As long as the markers are placed with a good spread there are no need for more than 3-4 markers in the dorsal part of the sacrum and the ileum. The precision is under 0.16 mm for translations and under 0.25 degrees for rotations. The accuracy (bias) of the system is under 0.065 mm for the translation and 0.05 degrees for the rotations.
Question: What is the movement in the SIJ during the active straight leg raise test (ASLR) in patients with chronic PGP?
Material & methods: All patients (n=9) included in paper 1 and all the Swedish patients (n=10) were examined with RSA. The movement in the SIJ was measured in supine position, and when the leg was raised 20 cm above the bench. The difference between these two positions was measured and compared to the clinical findings of the ASLR test.
Results: The material is collected, but not analysed.
Precision and Accuracy Measurement of Radiostereometric Analysis Applied to Movement of the Sacroiliac Joint
Clin Orthop Relat Res (in press)