Changes in Hip Labral Size Two Years After Arthroscopic Repair Are Correlated With Preoperative Measurements on Magnetic Resonance Imaging

Femoral Anteversion Angle as a Predictor of Anterior Hip Labral Length in Patients With Femoroacetabular Impingement Syndrome

Background

The relationship between hip rotational abnormalities and hip labral size has not been fully investigated.

Purposes

To (1) examine the correlation between rotational abnormalities of the hip and labral size, while also identifying other predictive values for hip labral size, and (2) explore whether femoral torsion will lead to increased labral size.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 180 patients (180 hips) with femoroacetabular impingement syndrome (FAIS) (mean age, 36.81 ± 10.17 years; 67 male, 113 female) who underwent hip arthroscopic surgery between January 2021 and May 2022 were included. The femoral version (FV), acetabular version, and combined version angles were measured on computed tomography, and the labral length and height at the 12-o'clock and 3-o'clock positions were measured on magnetic resonance imaging. The hips were categorized into 3 groups based on FV angle: small (SFV; <10°); moderate (MFV; ≥10° and ≤20°), and large (LFV; >20°), and group comparisons were performed. Linear correlation and regression analysis were employed.

Results

Predictive factors for labral length were FV angle (β = 0.298; P = .02), sex (β = -0.302; P < .001), and age (β = -0.169; P = .016) at 3 o'clock and lateral center-edge angle (LCEA; β = -0.208; P = .005) and age (β = -0.186; P = .011) at 12 o'clock. FV angle was positively correlated with labral length at 3 o'clock (r = 0.267; P < .001) and negatively correlated with age (r = -0.222; P = .003) and female sex (r = -0.202; P = .006). LCEA (r = -0.227; P = .002) and age (r = -0.205; P = .006) were negatively correlated with labral length at 12 o'clock. Labral length at 3 o'clock was significantly different between the LFV (n = 49 hips), MFV (n = 65 hips), and SFV (n = 66 hips) groups (9.85 ± 2.28, 8.89 ± 2.44, and 8.30 ± 2.05 mm, respectively; P = .027 for LFV vs MFV; P < .001 for LFV vs SFV).

Conclusion

Patients with FAIS who exhibited a higher FV angle were at a greater likelihood of having a larger anterior labral length. Increased femoral anteversion and decreased LCEA, male sex, and younger age were significantly associated with longer hip labral length.

Editorial Commentary: Diminished Hip Hypoplastic Labrum Predicts Poor Patient Outcomes After Non-augmented Primary Repair

Diminished hip labral size and tissue quality may be a predictor of poor patient outcomes when a non-augmented primary labral repair is performed. Labral augmentation is an option for patients with hypoplastic or degenerative labral tissue. The optimal graft for augmentation has yet to be identified, and biomechanical research shows no difference in force to suction-seal disruption between dermal allograft and iliotibial band allograft when used to augment the labrum. However, time-zero biomechanical studies do not reflect the biological ability of the graft to heal to surrounding structures, revascularization of the graft, durability of the graft, hip capsular status, and response to functional demands of the patient.

Labral Augmentation With Either Iliotibial Band Allograft or Dermis Allograft Perform Similarly Regarding Peak Force, Displacement, and Work to Labral Repair in Suction Seal Restoration: A Biomechanical Study

PURPOSE

To investigate whether allograft substitutes may be used to restore suctional seal properties with labral augmentation, the purpose of the current study was to evaluate the biomechanical properties of the labral suction seal under several scenarios, including: (1) intact labrum, (2) rim preparation, (3) labral repair, (4) labral augmentation with iliotibial band (ITB), and (5) labral augmentation with a dermis allograft.

METHODS

Eleven hemi-pelvises were dissected to the level of the labrum and placed in a material testing system for biomechanical axial distraction. Each specimen was compressed to 250 newtons (N) and distracted at 10 mm/s while load, crosshead displacement, and time were continuously recorded. For each of the 5 labral states, 3 testing repetitions were performed. Peak force (N, newtons), displacement at peak force (mm, millimeter), and work (N-mm, newton, millimeter) were calculated and normalized to the intact state of each specimen.

RESULTS

Eleven specimens were tested and 8 specimens (age: 58.6 ± 5.4 years, body mass index: 28.6 ± 6.8 kg/m2; 4 female patients; 5 right hips) were included in final analyses. Expressed as a percentage relative to the intact state, the average normalized peak force, displacement at peak force, and work for each labral state were as follows: intact (100.0% ± 0% for all), rim preparation (89.0% ± 9.2%, 93.3% ± 20.6%, 85.1% ± 9.0%), repair (61.3% ± 17.9%, 88.4% ± 36.9%, 58.1% ± 16.7%), ITB allograft (62.7% ± 24.9%, 83.9% ± 21.6%, 59.4% ± 22.4%), and dermis allograft (57.8% ± 27.2%, 88.2% ± 29.5%, 50.0% ± 20.1%). Regarding peak force, intact state was significantly greater compared with the labral repair, augmentation with ITB, and augmentation with the dermis allograft states (P < .001). No significant differences were demonstrated between displacement at peak force (P = .561). Regarding work, both intact state and rim preparation states were significantly greater than the repair, ITB augmentation, and dermis allograft augmentation states (P < .001). In all outcome measures, the dermis allograft augmentation performed with no statistical difference to the ITB augmentation state.

CONCLUSIONS

Labral repair and labral augmentation with either ITB allograft or the dermis allograft resulted in significantly lower peak force and work to equilibrium compared with the intact and rim prep states. There was no statistical difference between repair and augmentation states as well as no statistical difference between ITB allograft and dermal allograft at time zero.

CLINICAL RELEVANCE

This study compares biomechanical properties of the suction seal of the hip comparing labral states including intact, rim preparation, repair, and augmentation, which can be used for surgical decision-making.

The Air-Lift Technique for Improving Ease and Safety When Establishing the Modified Midanterior Portal in Hip Arthroscopy

Hip arthroscopy continues to increase in popularity and has an ever-expanding range of indications; however, the steep learning curve introduces significant risk of iatrogenic chondrolabral injury when accessing the joint and establishing arthroscopic portals. This article presents a technique for establishing the modified midanterior portal and is particularly useful when the available space is tight. We present "the air-lift" as a safe and simple adjunct to standard portal creation when performing hip arthroscopy in the supine position.

Acetabular Labral Repair and Selective Labral Debridement Show No Significant Difference in Clinical Outcomes at a Minimum 2-Year Follow-Up

PURPOSE

To compare the outcomes of arthroscopic labral repair using looped type suture with a matched-pair selective labral debridement with a minimum 2-years follow-up.

METHODS

We identified 378 patients undergoing primary arthroscopic labral repair using loop-suture and selective labral debridement from January 2, 2018, to December 28, 2020. The labral repair group was matched 1:1 to a selective labral debridement control group by age, sex, body mass index, follow-up period, lateral center-edge angle, Tönnis grade, and preoperative joint space. Before surgery, 3-Tesla radial magnetic resonance imaging with a 3-dimensional double-echo steady-state sequence was obtained following failed nonoperative treatment lasting more than 3 months. Follow-up imaging was conducted at a minimum of 2 years. In both groups, the ratio of positive slices in which a disrupted chondrolabral junction was observed between the 2 o'clock and 11 o'clock positions was measured. Patient-reported outcome scores included the Harris Hip Score, visual analog score, Hip Outcome Score Activities of Daily Living Subscale, and Hip Outcome Score of Sport-Specific Subscale.

RESULTS

In total, 76 patients of the repair group were matched to 76 controls with a minimum 2-years follow-up (repair vs control: 2.6 ± 0.4 vs 2.6 ± 0.4 years, P = .775). The repair group experienced a 2-fold improvement (0.6 ± 0.1 to 0.3 ± 0.1, P＜.001). Although the selective debridement group experienced a 3-fold improvement (0.3 ± 0.1 to 0.1 ± 0.1, P＜.001). Significant improvement of the patient-reported outcome was shown in both groups at final follow-up without significant difference between the 2 groups.

CONCLUSIONS

The mid-term clinical outcomes are comparable between the labral repair using looped type suture and selective labral debridement group. Although a gap between the labrum and articular cartilage may appear in 3-dimensional double-echo steady-state magnetic resonance imaging results after labral repair, it does not correspond with clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Editorial Commentary: Diminished Hip Labral Width May Predict Inferior Outcome After Hip Femoroacetabular Impingement Surgery: Diminutive Labral Width Is a Relative Indication for Labral Reconstruction

Hip labral "width" should be defined as the distance from the chondrolabral junction to the tip of the labrum in triangular cross-section. "Height" should refer to the distance from the joint surface to the perilabral recess (perpendicular to the width). "Length" is the distance from the anterior end of the labrum, adjacent to the anterior transverse acetabular ligament (TAL), to the posterior end of the labrum, adjacent to the posterior TAL (as may be relevant in reconstructions). Most studies of labral size focus on width, as it is thought to most contribute to the suction seal effect and hip stability. Magnetic resonance imaging most accurately measures labral width. Labral width at the time of surgery should be considered its maximal size; the labrum is reduced in size after repair. Hypoplastic labrums may result in worse outcomes after hip arthroscopy, and hyperplastic labrums may result in higher scores than normoplastic labrums in patients with primary femoroacetabular impingement syndrome. Diminutive labral width is a relative indication for labral reconstruction.