Presentation
Posterior right buttock pain. Previous MRI showed marked narrowing of the ischiofemoral intervals and edema within the quadratus femoris muscles.
Patient Data
Planning CT with overlying marking grid. Lateral approach with a 22 gauge Quincke needle. Contrast confirms an excellent needle position.
After the steroid-containing injectate is administered, it dilutes the existing iodinated contrast, and the full spread of the steroid-containing injectate is demonstrated.
Case Discussion
Quadratus femoris injections are performed for ischiofemoral impingement, where there is quadratus femoris impingement. Both CT and US are used, but US can be more difficult with those with a larger habitus.
The sciatic nerve is the most important structure to avoid and should be identified regardless of imaging modality. A lateral approach means the needle passes inferior to the sciatic nerve. Using a short-acting and smaller amount of local anesthetic i.e. 1% lidocaine, reduces the risk of a long-lasting post-procedure sciatic nerve block.