Comprehensive clinical and SPECT/CT findings in 253 patients with an established diagnosis of SIJI are presented.
Methods All patients with a clinically diagnosis of SIJI following the European guidelines for Pelvic Girdle Pain were studied by SPECT/CT. Patients were followed up by interview at 6 months after therapy (directed physiotherapy or prolotherapy). For SPECT/CT, patients were injected intravenously with 900–1000 MBq of 99m Tc HDMP and planar images obtained followed by SPECT/CT from the level of the lesser trochanters upwards. Images were reported by 2 experienced nuclear medicine physicians.
Results The average age of the 253 patients was 42 years (15–71 yrs) with 65% F, 35% M. Average length of history was 3.5 years (6 weeks to 26 years). Trauma was implicated in 84% of cases and post-partum back pain in 9%. Clinical scores for SIJI were an average of 3.4 by the European guidelines. All patients showed SIJ uptake and loss of the normal configuration of joint uptake with ligament uptake. Joint sclerosis was observed in 98.8%. Hamstring enthesopathy was present on the ipsilateral side in 39% and on the opposite side in 61%. Adductor enthesopathy was present on the ipsilateral side in 66% and on the opposite side in 57% with bilateral involvement in 23%. Ipsilateral hip impingement was present in 72%. Extra finding were evicent in 56%.
Conclusion We have confirmed the integrity of SPECT/CT in a large cohort of patients with SIJI with specific treatment of the condition yielding good clinical results, in spite of the average length of the clinical history being 3.5 years.
The SPECT/CT findings (metabolic changes at the relevant bone-ligamentous interface) and the clinical progress of patients confirm the validity of the self-bracing mechanism proposed by Vleeming and Lee (1998).