Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction: Comparison of Femoroacetabular Biomechanics

Abstract

Background: The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal.

Purpose/hypothesis: To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal.

Study design: Controlled laboratory study.

Methods: Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions.

Results: PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P > .06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P = .003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62).

Conclusion: Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state.

Clinical relevance: These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity.

Keywords: autograft; hip; labrum; polyurethane scaffold; reconstruction.

Figure 1.

(a) Polyurethane scaffold and fascia lata autograft. Reconstruction with (b) polyurethane scaffold and (c) fascia lata autograft. (b, c) On specimen 4 (left side), there are 3 anchors and 2 side-to-side translabral sutures.

Figure 2.

Contact areas for the intact, PS, and FLA conditions: (a-d) flexion, flexion + internal rotation (FLA vs intact, P = .006), flexion + external rotation, and extension. X, mean; horizontal line, median; top and bottom of box, first and third quartiles; whiskers, range; dots, outliers. *P < .01 vs intact. FLA, fascia lata autograft; PS, polyurethane scaffold.

Figure 3.

Contact pressure for the intact, PS, and FLA conditions: (a-d) flexion (PS vs intact, P = .003; FLA vs intact, P = .002), flexion + internal rotation (PS vs intact, P = .008; FLA vs intact, P = .005), flexion + external rotation (PS vs intact, P = .0004; FLA vs intact, P = .002), and extension (PS vs intact, P = .005; FLA vs intact, P = .05). X, mean; horizontal line, median; top and bottom of box, first and third quartiles; whiskers, range; dots, outliers. FLA, fascia lata autograft; PS, polyurethane scaffold.

Figure 4.

Peak force for the intact, PS, and FLA conditions: (a-d) flexion (FLA vs intact, P = .002), flexion + internal rotation, flexion + external rotation (FLA vs intact: P = .008), and extension. X, mean; horizontal line, median; top and bottom of box, first and third quartiles; whiskers, range; dots, outliers. FLA, fascia lata autograft; PS, polyurethane scaffold.