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

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.

Hip Labral Reconstruction With a Polyurethane Scaffold: Restoration of Femoroacetabular Contact Biomechanics.

Background: Many advances have been made in hip labral repair and reconstruction and in the restoration of the suction seal. Purpose/Hypothesis: The purpose of this study was to evaluate the biomechanical effects of segmental labral reconstruction with a synthetic polyurethane scaffold (PS) in comparison with segmental labrectomy. Our hypothesis was that reconstruction with a icroporous polyurethane implant would normalize joint kinetics of the hip and restore the suction seal. Study Design: Controlled laboratory study. Methods: We used 10 hips from 5 fresh-frozen pelvises with an intact acetabular labrum without osteoarthritis. Using an intra-articular pressure measurement system, the contact area, contact pressure, and peak force were assessed for the following conditions: intact labrum, partial anterosuperior labrectomy, and PS reconstruction. For each condition, all specimens were analyzed in 4 positions (90° of flexion, 90° of flexion and internal rotation, 90° of flexion and external rotation, and 20° of extension) and underwent a labral seal test. The relative change from the intact condition was determined for all conditions and positions. Results: Compared with the intact labrum, labrectomy resulted in a significant decrease in the contact area (P < .001) and a significant increase in the peak force (P < .001) and contact pressure (P < .001) across all positions. Compared with labrectomy, PS reconstruction resulted in a significant increase in the contact area (P < .001) and a significant decrease in the contact pressure (P ≤ .02) and peak force (P < .001) across all positions. Compared with the intact labrum, PS reconstruction restored the contact area and peak force to normal values in all positions (P > .05), whereas the contact pressure was significantly decreased compared with labrectomy (P < .05) but did not return to normal values. The labral seal was lost in all specimens after labrectomy but was restored in 80% of the specimens after PS reconstruction. Conclusion: Femoroacetabular contact biomechanics significantly worsened after partial labrectomy; reconstruction using a PS restored the contact area and peak force to the intact state and improved the contact pressure increases seen after partial labrectomy. The contact area and peak force were normalized, and the labral seal was re-established in most cases. Clinical Relevance: This study provides biomechanical evidence for the use of a scaffold for labral reconstruction.

Labral reconstruction with polyurethane implant.

Surgical treatment of labral injuries has shifted from debridement to preservation over the past decades. Primary repair and secondary augmentation or reconstruction techniques are aimed at restoring the labral seal and preserving or improving contact mechanics. Currently, the standard of care for non-repairable tears favours the use of auto- or allografts. As an alternative, we present our initial experience using a synthetic, off-the-shelf polyurethane scaffold for augmentation and reconstruction of segmental labral tissue loss or irreparable labral damage. Three patients aged 37-44 (two male, one female) with femoroacetabular impingement without associated dysplasia (Wiberg > 25°) or osteoarthritis (Tönnis <2) were included in this series. Labral reconstruction (one case) and augmentation (two cases) were performed using a synthetic polyurethane scaffold developed for meniscal substitution (Actifit®, Orteq Ltd, London, UK) and adapted to the hip. Clinical results were analysed with patient-reported outcomes (PROMs) using non-arthritic hip score (NAHS) and daily live activities hip outcome score (DLA HOS) and magnetic resonance images (MRI) at 2- and 4-year follow-up. Clinically improvement was seen in all PROMs at 4 years. The NAHS scores improved from 57.7 to 82.3 (50.9% improvement) and HOS from 59 to 79.3 (35.3% improvement). Last follow-up MRIs confirmed the presence of the scaffold; however, the scaffold signal was still hyperintense compared to native labrum. There was no shrinkage in any scaffold and no progression to hip osteoarthritis seen. Reconstruction or augmentation of segmental labral defects with a polyurethane scaffold may be an effective procedure. At 4 years after implantation, our small cases series resulted in improved hip joint function, reduced pain and scaffold preservation on follow-up imaging.

Severe Weakness of Hip Flexor after Iliopsoas Tenotomy: Two Case Reports.

Hip arthroscopies are becoming a standard surgical technique, with psoas tenotomy being a relatively common procedure during this operation. A 37-year-old male and a 42-year-old female with internal hip snapping came to our department. Arthroscopic partial psoas tenotomy of the iliopsoas portion of the conjoint tendon was performed, but its results were bad. Patients reported preoperative unilateral low-back pain and weakness when flexing the hip. Unilateral atrophy of the lumbar psoas and fatty multifidus were detected in both cases. Patients at risk of unsatisfactory outcomes after psoas tenotomy should be ideally identified prior to surgery. Warning symptoms, physical examination, and imaging studies should be considered to avoid unsatisfactory results.

Arthroscopic Reduction and Internal Fixation of a Rim Fracture.

Femoroacetabular impingement is uncommonly associated to a rim fracture. Complete resection of the fragment might result in iatrogenic instability or poor femoral head coverage. In this report, we describe the step-by-step surgical technique of arthroscopic partial resection of a rim fracture, reduction and internal fixation of the remaining fragment to correct the impingement, and preserve the adequate acetabular coverage.

Epiphyseal femoral tumour resection under intraosseous endoscopic control.

We have resected 4 benign cystic femoral head tumours under intraosseous endoscopic control. The resections were completely extraarticular through a tunnel made in the femoral neck from the lateral cortex. The procedures were assessed endoscopically with the help of a standard arthroscope. With a minimum follow-up of 1 year (range 1-16 years), there were no recurrences. Mean age at time of surgery was 23 years (range 19-26 years). Only 1 (fibrous defect) needed prophylactic osteosynthesis with a dynamic hip screw. The lateral approach through a bone tunnel allows preservation of the joint. The creation of a wider tunnel (10-15 mm) avoids the need for an irrigation system, without debilitating the bone structure, and simplifies the surgical procedure.