The sonoanatomy of lumbar erector spinae and its iliac attachment - the potential substrate of the iliac crest pain syndrome, an ultrasound study in healthy subjects.

BACKGROUND: Iliac crest pain syndrome is a regional pain syndrome that has been identified in many patients with low back pain. Based on anatomical studies, it was suggested that the potential substrate of this syndrome might be the enthesis of the erector spinae muscle at the posterior medial iliac crest. As there have been no imaging studies of this important enthesis, our aim was to assess its characteristics by ultrasound. METHODS: Erector spinae enthesis was first studied in a cadaver. Then its characteristics were recorded in 25 healthy volunteers (median age: 28.92, SD: 5.31, mean Body Mass Index 22.61, SD: 3.38), with Esaote My Lab 7 machine using linear transducer (4-13 MHz). RESULTS: The cadaver study confirmed the attachment of a substantial part of erector spinae to a well-defined region on the medial posterior iliac crest. The US study in the volunteers consistently showed the entheses as typical hyperechoic fibrillar structures, slightly oblique to the skin in the longitudinal plane and attaching to the iliac crest. In the transverse plane, the entheses were seen as oval, densely dotted structures in contact with the superior edge of posterior superior iliac spine. Their mean thickness (4.9 ± 0.6 and 5.2 ± 0.7 mm longitudinally; 4.3 ± 0.6 and 4.4 ± 0.7 mm transversely), maximum width (16.3 ± 2.8 and 15.7 ± 2.3 mm) and depth (10.8 ± 7.3 and 10.6 ± 6.2 mm) on the left and right side, respectively, as well as their echostructure were recorded and described. CONCLUSIONS: The erector spinae entheses could be assessed in detail by ultrasound, thus their pathological transformation associated with iliac crest pain syndrome could be identified.

Comparison between the Effect of Local Steroid Injection and Prolotherapy on Iliac Crest Pain Syndrome

OBJECTIVE: To evaluate the therapeutic effect of local steroid injection and prolotherapy on the iliac crest pain syndrome (ICPS) in patients with nonspecific low back pain. METHOD: 44 patients with ICPS were chosen randomly. The treatment groups were divided into two. The first group received a mixture of triamcinolone and lidocaine. The second received with a mixture of dextrose and lidocaine. The patients in each group were injected once a week over 4 weeks. The effectiveness of treatment was evaluated by a visual analogue scale (VAS), a pressure threshold and patient's life activities with modified Oswestry questionnaire before injection, 30 minutes, 1 week, 4 weeks and 3 months later after injection respectively. RESULTS: VAS, pressure threshold and patient's life activities of two groups were all improved at 30 minutes, 1 week, 1 month and 3 months after injection compared with those of pre-injection, and there was no significant difference between groups. CONCLUSION: The low back pain on ICPS can be significantly improved by local steroid injection and prolotherapy equally. Therefore, patients with risk of steroid injection could be treated by prolotherapy.