Rocco Hlis

Piriformis syndrome is a common pain condition affecting the buttock and posterior hip with or without radiation to the leg, and management of the condition involves many treatments. In this study, we hypothesize that a CT-guided injection with botulinum toxin is more effective in providing pain relief than a CT-guided injection without Botox. Overall, 97 consecutive patients with piriformis syndrome presented for a CT-guided injection of the piriformis muscle and perineural injection of the sciatic nerve. After the injection, the patients received a visual analog scale pain log to record their pain level until the follow-up appointment. P values of less than 0.2 were considered as confounder and adjusted by inverse probability of treatment weighting (IPTW) via propensity score. The effect of botulinum toxin on 48-hour response and duration of response was tested using weighted chi-square test and weighted Kaplan-Meier analysis. There was a total of 97 patients in the study, and 111 injections, as some patients had bilateral injections. Patients in the Botox group had more 48-hour response than patients in the non-botulinum toxin group (P < 0.001 with IPTW, P = 0.005 without IPTW). Median pain-free survival was 30 days for Botox group and 1 day for non-Botox group (P = 0.059 with IPTW, P = 0.10 without IPTW). CT-guided injections with botulinum toxin for patients with piriformis syndrome are more likely to lead to a positive response and a longer duration of response than patients who receive a CT-guided injection without botulinum toxin. We hope that this study facilitates future prospective randomized blind trials for patients with suspected piriformis syndrome.

Introduction: To conduct a morphometric analysis of intact and torn menisci using isotropic meniscus plane three‐dimensional (3D) reconstructions on 3‐Tesla MRI and compare 2D versus 3D MRI for meniscus tear characterization.Materials and methods: One hundred thirty three normal menisci from 92 patients (39 male, 53 female), and 38 arthroscopy‐proven torn menisci from 36 patients (23 male, 13 female) were evaluated using 3D isotropic multi‐planar MRI reconstructions and 2D MRI. Two observers measured the tibial plateau height and area, meniscal height, axial plane cross‐sectional areas, and extrusion of intact menisci. Two observers also measured the meniscal tear length, tear area, and residual area of pathological menisci on 2D and 3D MRI. Intraclass correlation coefficients (ICC) were obtained. Institutional Review Board approval was obtained, and the informed consent was waived.Results: Medial meniscus (MM) and lateral meniscus (LM) areas were 503.6 ± 85.1 mm² and 396.6 ± 72.0 mm² for Observer 1, and 515.8 ± 82.1 mm² and 408.0 ± 68.3 mm² for Observer 2 (ICC:0.86, 0.87). In torn menisci, average tear length, area, and residual area were 36.3 ± 13.6 mm, 182.6 ± 139.3 mm², and 235.4 ± 140.3 mm², respectively for Observer 1, and 38.9 ± 14.7 mm, 181.2 ± 135.6 mm², 238.2 ± 140.5 mm² for Observer 2. In the MM and LM, bucket‐handle and complex tears were largest in areas, respectively. ICCs were excellent (0.91–1.0) on 3D MRI and moderate‐good (0.57–0.81) on 2D MRI.Conclusion: Meniscus morphometry on 3D MRI shows moderate to excellent inter‐observer reliability and meniscus tear extent is more reliably defined on 3D MRI than 2D MRI. Residual meniscus‐area calculation can be performed on 3D MRI.

Objective To evaluate the inter-rater and intermethod correlation (reliability between MRI and arthroscopy) of knee for findings of meniscus tears using International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) classification on both 1.5 and 3.0 T images. Methods 81 knees were evaluated in 69 patients aged 30.0±12.6 years (mean±SD). Consecutive arthroscopy-proven meniscal tears were evaluated by two board-certified radiologists on MRI and two sports surgeons on arthroscopies. The surgically validated ISAKOS classification of meniscal tears was used to describe medial meniscus (MM) and lateral meniscus (LM) tears on MRI and re-evaluation of images from completed arthroscopies. Prevalence-adjusted bias-adjusted kappa (PABAK), t-tests and intraclass correlation coefficient (ICC) were calculated. Results For LM on 1.5 T, the agreements for location, depth, tear length and pattern were good to excellent in all categories except fair for tissue quality (PABAK=0.35–0.41) and zone 2 (PABAK=0.35) identification. For MM, the agreements were good to excellent in all except moderate for tissue quality (PABAK=0.6) and zone 1 and 3 (PABAK=0.40–0.47), and fair for zone 2 identification (PABAK=0.27). Similar results were seen on 3 T with improved LM zonal identification (PABAK=0.52–0.90) and better correlation of tear lengths, which were different on 1.5 T vs 3.0 T (p=0.01–0.03). For 1.5 T cases, both MM and LM tear lengths were larger on MRI versus arthroscopy (MM, p=0.004; LM, p=0.095). For 3 T, the MM tear lengths were larger on MRI versus arthroscopy (p=0.001). Conclusion ISAKOS classification of meniscal tears on both 1.5 and 3.0 T MRI provides satisfactory inter-rater and intermethod reliability for use in clinical practice. Level of evidence: IV.