Reliability and Reproducibility of a Novel Grading System for Lesions of the Ligamentous-Fossa-Foveolar Complex in Young Patients Undergoing Open Hip Preservation Surgery

Abstract

Background: Several classification systems based on arthroscopy have been used to describe lesions of the ligamentum teres (LT) in young active patients undergoing hip-preserving surgery. Inspection of the LT and associated lesions of the adjuvant fovea capitis and acetabular fossa is limited when done arthroscopically but is much more thorough during open surgical hip dislocation. Therefore, we propose a novel grading system based on our findings during surgical dislocation comprising the full spectrum of ligamentous-fossa-foveolar complex (LFFC) lesions. Purpose: To determine (1) intraobserver reliability and (2) interobserver reproducibility of our new grading system. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: We performed this validation study on 211 hips (633 images in total) with surgical hip dislocation (2013-2021). We randomly selected 5 images per grade for each LFFC item to achieve an equal representation of all grades (resulting in 75 images). The ligament, fossa, and fovea were subcategorized into normal, inflammation, degeneration, partial, and complete defects. All surgeries were performed in a standardized way by a single surgeon. The femur was disarticulated using a bone hook, the LT was inspected, documented and resected, then the fossa and fovea were documented with the femoral head in full dislocation using a 70° arthroscope. Six observers with different levels of expertise in hip-preserving surgery independently conducted the measurements twice, and intraclass correlation coefficients (ICC) were calculated to determine (1) intraobserver reliability and (2) interobserver reproducibility of the novel grading system. Results: For intraobserver reliability, excellent ICCs were found in both the junior and the experienced raters for grading the ligament, fossa, fovea, and total LFFC (ICCs ranged from 0.91 to 0.99 for the LFFC score). We found excellent interobserver reproducibility between raters for all items of the LFFC (all interobserver ICCs ≥ 0.76). Conclusion: Our new grading system for lesions of the LFFC is highly reliable and reproducible. It covers the full spectrum of damage more precisely than arthroscopic classifications do and offers a scientific basis for standardized intraoperative evaluation.

Are degenerative findings detected on traction MR arthrography of the hip associated with failure of arthroscopic femoroacetabular impingement surgery?

“…This finding supports intraoperative observations suggesting that central femoroacetabular osteophytes lead to degeneration of the ligamentum teres and secondary femoral cartilage wear. This pattern of degeneration differs from the initial stages of FAI, in which the damage is confined to the chondrolabral transition zone [ 23 ].…”

Persistent femoral neck non-union despite valgus intertrochanteric osteotomy: Relevance for secondary cam-type impingement

“…In addition, a chondro-labral separation (Bern type 5 labral lesion) from 12 o'clock to 3 o'clock was also seen [ 14 ]. The ligamentum teres showed signs of reactive inflammation (Stetzelberger ligamentous-fossa-foveolar complex grade 1) [ 15 ]. Inspection of the femoral head cartilage revealed focal degeneration at the 12 o'clock position.…”