Poster 199: The Hip Suction Seal Restoration Using the Circumferential Labral Reconstruction. The Role of The Graft Width

OBJECTIVES: BACKGROUND: Favorable patient-reported outcomes has been reported following circumferential labral reconstruction (CLR);however, there is a paucity on biomechanical data following CLR. PURPOSE: To evaluate the role of the CLR using iliotibial band (ITB) allograft on the restoration of the distractive stability force (suction seal), and to evaluate whether any correlation existed between ITB allograft width and the distractive stability restoration after CLR. HYPOTHESIS: 1) CLR using a wider ITB allograft would restore the distractive stability force to a level comparable to the intact labrum. 2) Wider CLR would achieve significantly superior distractive stability force when compared to CLR using smaller width allograft. METHODS: 14 fresh-frozen cadaveric hips consisting of hemipelvis and proximal femur with intact labra and without osteoarthritis (Tönnis > 1) were dissected free of all soft tissue including the hip capsule. Each hip underwent two CLR using ITB allograft, width > 6.5mm (7.5-8.0mm) and width <6.5mm (4.5-5.0mm), the order of the reconstruction was assigned in a randomized fashion. Each hemipelvis was potted, placed in the saline bath, and securely fixed to the frame of a hydraulic testing system with the hip being placed in 30° of abduction. A 500N·m compressive load was applied to the acetabulum followed by a distraction at the rate of 5.0mm/s. Force and displacement were recorded throughout the distraction until the suction seal ruptured. Measures were performed in each hip for intact labrum, deficient (excised) labrum, first CLR, and second CLR. RESULTS: The distraction force was comparable between the intact state and the CLR >6.5mm (P = 0.587). Further, the distraction force was comparable between the deficient state and the CLR <6.5mm (P = 0.418). When comparing the CLR <6.5mm and CLR >6.5mm, the distraction force was significantly higher for the latest (P = 0.01). Also, the CLR >6.5mm outperformed the deficient state (P = 0.001). Similarly, the distance to suction seal rupture was comparable between the intact state and the CLR >6.5 mm (P = 0.587), comparable for the deficient state and the CLR < 6.5mm (P = 0.418), significant longer for the CLR >6.5mm when compared to the CLR < 6.5mm and the deficient state (P = 0.01 and P = 0.001, respectively).[MOU1]. CONCLUSIONS: The allograft width following CLR was found to be correlated with the hip suction seal restoration in a cadaveric model. CLR using an ITB allograft > 6.5mm was found to restore the distractive stability force to values comparable to the native intact labral state. Further, when compared to the CLR using ITB allograft with a width < 6.5mm, the CRL >6.5 mm outperformed by demonstrating significantly superior distractive stability force restoration. CLINICAL RELEVANCE: The allograft width for CRL was correlated with the hip suction seal effect restoration in a cadaveric model. Although further studies would be required to identify the clinical effects of the CLR allograft width, it seems appropriate to selecting allograft > 6.5mm in the clinical setting.