The Hip Suction Seal, Part II: The Effect of Rim Trimming, Chondrolabral Junction Separation, and Labral Repair/Refixation on Hip Distractive Stability

Hip Circumferential Labral Reconstruction Provides Similar Distractive Stability to Labral Repair After Cam Over-Resection in a Biomechanical Model

PURPOSE

To evaluate the change in hip distractive stability after a cam over-resection, labral tear, repair, labrectomy, or circumferential 6- or 10-mm labral reconstruction in a biomechanical model.

METHODS

Ten fresh-frozen matched-pair human cadaveric hips were analyzed using a materials testing system to measure the force and distance required to disrupt the suction seal of the hip (1) with an intact capsule and labrum; (2) after a capsulectomy and labral repair; (3) after a capsulectomy, 5-mm cam over-resection and labral repair; (4) after a capsulectomy, 5-mm cam over-resection and labral tear; (5) after a capsulectomy, 5-mm cam over-resection and labrectomy; and (6) after a capsulectomy, 5-mm cam over-resection and a 6- or 10-mm circumferential labral reconstruction with iliotibial band (5 hips each). Each specimen was retested at 0° flexion, 45° flexion, and 45° flexion and at 15° internal rotation and analyzed using nonparametric statistical methods.

RESULTS

The Friedman test of differences was significant among structural conditions and hip positions (P = .001). In all positions, the resistive force that opposed the disruption of the suction seal in an intact hip was significantly greater compared with all other conditions. The resistive force for the capsulectomy, 5-mm cam over-resection and labrectomy condition was significantly less compared with almost all other conditions and hip positions. A qualitative suction seal was achieved in 20% of hip specimens with a 6-mm labral reconstruction, whereas a seal was in achieved 60% of specimens with a 10-mm labral reconstruction.

CONCLUSIONS

After a cam over-resection, a circumferential labral reconstruction improves the distractive stability of a labral deficient hip, comparable to a labral repair or tear in a biomechanical model.

CLINICAL RELEVANCE

Circumferential labral reconstruction may be a viable treatment option for patients with ongoing symptoms after hip arthroscopy with evidence of a cam over-resection and a deficient labrum.

The Contribution of Soft Tissue and Bony Stabilizers to the Hip Suction Seal: A Systematic Review of Biomechanical Studies

BACKGROUND

Previous biomechanical studies have identified capsular closure, labral repair or reconstruction, and osteochondroplasty as important surgical interventions to improve hip stability.

PURPOSE

To investigate the outcome metrics used to quantify hip stability and assess and measure the relative contributions of the labrum, capsule, and bone to hip stability through a quantitative analysis.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed and Embase databases were searched using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included studies evaluated cadaveric hip biomechanics related to capsular, labral, and bony management during hip arthroscopy. Studies were assessed for distraction force and distance, fluid measures, and contact forces used to quantify the suction seal. Exclusion criteria included open surgery, arthroplasty, reorientation osteotomy, or traumatic dislocation.

RESULTS

A total of 33 biomechanical studies comprising 322 hips that evaluated 1 or more of the following were included: distraction force or distance (24 studies), fluid measures (10 studies), and contact forces (6 studies). Compared with a capsulotomy or capsulectomy, capsular repair or reconstruction demonstrated greater resistance to distraction (standardized mean difference [SMD], 1.13; 95% CI, 0.46-1.80; P = .0009). Compared with a labral tear, a labral repair or reconstruction demonstrated less resistance to distraction (SMD, -0.67; 95% CI, -1.25 to -0.09; P = .02). Compared with a labral debridement, repair or reconstruction demonstrated greater resistance to distraction (SMD, 1.74; 95% CI, 1.23 to 2.26; P < .00001). No quantitative analysis was feasible from studies evaluating the effect of osseous resection due to the heterogeneity in methodology and outcome metrics assessed.

CONCLUSION

Most biomechanical evidence supports capsulotomy repair or reconstruction to improve hip distractive stability at the end of hip arthroscopic surgery. While the repair of a torn labrum does not improve distractive resistance, it is superior to labral debridement in most biomechanical studies.

Association Between Severity of Chondrolabral Junction Breakdown and Functional Outcomes After Hip Arthroscopy for Acetabular Labral Tears

BACKGROUND

Despite focus on surgical preservation of the chondrolabral junction (CLJ), the transition zone between the acetabular cartilage and labrum, the association between severity of CLJ breakdown and functional outcomes after hip arthroscopy remains unexplored.

PURPOSE

To assess the influence of CLJ breakdown on patient-reported outcome measures (PROMs) at a 24-month follow-up after hip arthroscopy for symptomatic labral tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of prospectively collected data was conducted to identify patients ≥18 years of age with a minimum 24-month follow-up who underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to femoroacetabular impingement. The Beck classification of transition zone cartilage was used to grade CLJ damage; patients with grades 0 to 2 were stratified into the mild CLJ damage cohort, and those with grades 3 and 4 were stratified into the severe CLJ damage cohort. PROMs were collected at baseline and at 3, 6, 12 months, and annually thereafter postoperatively. Linear mixed-effects models were used to compare PROMs. Rates of achieving clinically meaningful thresholds and subsequent surgery rates were also compared.

RESULTS

In total, 198 patients met the inclusion criteria, with a mean follow-up of 3.54 ± 1.26 years. A total of 95 patients with severe CLJ damage (mean age, 34.9 ± 10.5 years) were compared with 103 patients with mild CLJ damage (mean age, 38.2 ± 11.9 years). Hip Outcome Score-Activities of Daily Living (HOS-ADL), Non-Arthritic Hip Score (NAHS), and visual analog score for pain were inferior in the severe CLJ group at enrollment and all follow-up time points (P≤ .05). However, patients with severe CLJ breakdown exhibited greater improvements in HOS-ADL and NAHS at the 24-month follow-up and achieved clinically meaningful thresholds at equivalent rates to patients with mild CLJ breakdown. Subsequent surgery rates were 6.8% and 12.6% in patients with mild versus severe CLJ damage, respectively (P = .250).

CONCLUSION

Severe CLJ breakdown is associated with increased pain and decreased functional level preoperatively and up to 24 months after hip arthroscopy. Despite this, patients with severe CLJ breakdown experienced greater improvements in functional outcomes at a 24-month follow-up and achieved clinical thresholds at similar rates to patients with mild CLJ damage. Thus, while worse baseline pain and functional levels may indicate severe CLJ breakdown, these patients still benefit substantially from hip arthroscopy.

Editorial Commentary: Protected Physical Therapy and Rehabilitation Is Essential After Hip Capsule and Labral Repair

Hip arthroscopy is an effective procedure with rapidly improving techniques and implants. Routine labral and capsular repair are broadly agreed upon as standard of care in most cases, which is now supported by long-term outcome studies. A crucial component of patient postoperative success is physical therapy. While accelerated programs are appealing, biomechanical studies have consistently demonstrated decreased stability at time zero after hip arthroscopy, particularly labral repairs. Therefore, although we want to help our patients get back to their lives as soon as possible, it remains our responsibility to protect their hip in the early postoperative period. If, in ideal laboratory conditions, we cannot restore stability to an intact state, then we must presuppose that the suction seal improves as the capsule, and more importantly, the labrum, heals after surgical manipulation. This means we are not able to rely solely on the strength of our repair, and there is a distinct period where the repaired hip is particularly vulnerable. Most hip arthroscopy protocols use a protective period, ranging from 4 to 8 weeks, during which there is an emphasis on passive range of motion only, with a strict moratorium on "pushing beyond pain."

Indirect Head of the Rectus Femoris Tendon as a Graft for Segmental Hip Labral Reconstruction: An Anatomic, Radiographical, and Biomechanical Study in Comparison With Iliotibial Labral Reconstruction

BACKGROUND

The indirect head of the rectus femoris (IHRF) tendon has been used as an autograft for segmental labral reconstruction. However, the biomechanical properties and anatomic characteristics of the IHRF, as they relate to surgical applications, have yet to be investigated.

PURPOSE

To (1) quantitatively and qualitatively describe the anatomy of IHRF and its relationship with surrounding arthroscopically relevant landmarks; (2) detail radiographic findings pertinent to IHRF; (3) biomechanically assess segmental labral reconstruction with IHRF, including restoration of the suction seal and contact pressures in comparison with iliotibial band (ITB) reconstruction; and (4) assess potential donor-site morbidity caused by graft harvesting.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A cadaveric study was performed using 8 fresh-frozen human cadaveric full pelvises and 7 hemipelvises. Three-dimensional anatomic measurements were collected using a 3-dimensional coordinate digitizer. Radiographic analysis was accomplished by securing radiopaque markers of different sizes to the evaluated anatomic structures of the assigned hip.Suction seal and contact pressure testing were performed over 3 trials on 6 pelvises under 4 different testing conditions for each specimen: intact, labral tear, segmental labral reconstruction with ITB, and segmental labral reconstruction with IHRF. After IHRF tendon harvest, each full pelvis had both the intact and contralateral hip tested under tension along its anatomic direction to assess potential site morbidity, such as tendon failure or bony avulsion.

RESULTS

The centroid and posterior apex of the indirect rectus femoris attachment are respectively located 10.3 ± 2.6 mm and 21.0 ± 6.5 mm posteriorly, 2.5 ± 7.8 mm and 0.7 ± 8.0 mm superiorly, and 5.0 ± 2.8 mm and 22.2 ± 4.4 mm laterally to the 12:30 labral position. Radiographically, the mean distance of the IHRF to the following landmarks was determined as follows: anterior inferior iliac spine (8.8 ± 2.5 mm), direct head of the rectus femoris (8.0 ± 3.9 mm), 12-o'clock labral position (14.1 ± 2.8 mm), and 3-o'clock labral position (36.5 ± 4.4 mm). During suction seal testing, both the ITB and the IHRF reconstruction groups had significantly lower peak loads and lower energy to peak loads compared with both intact and tear groups (P = .01 to .02 for all comparisons). There were no significant differences between the reconstruction groups for peak loads, energy, and displacement at peak load. In 60° of flexion, there were no differences in normalized contact pressure and contact area between ITB or IHRF reconstruction groups (P > .99). There were no significant differences between intact and harvested specimen groups in donor-site morbidity testing.

CONCLUSION

The IHRF tendon is within close anatomic proximity to arthroscopic acetabular landmarks. In the cadaveric model, harvesting of the IHRF tendon as an autograft does not lead to significant donor-site morbidity in the remaining tendon. Segmental labral reconstruction performed with the IHRF tendon exhibits similar biomechanical outcomes compared with that performed with ITB.

CLINICAL RELEVANCE

This study demonstrates the viability of segmental labral reconstruction with an IHRF tendon and provides a detailed anatomic description of the tendon in the context of an arthroscopic labral reconstruction. Clinicians can use this information during the selection of a graft and as a guide during an arthroscopic graft harvest.

Hip Labral and Capsular Repair Are Unable to Restore Distractive Stability in a Biomechanical Model

PURPOSE

To evaluate the change in hip distractive stability after a capsulotomy, labral tear, and simultaneous repair of both the capsule and the labrum in a biomechanical model.

METHODS

Ten fresh-frozen human cadaveric hips were analyzed using a materials testing system to measure the distractive force and distance required to disrupt the hip suction seal under the following conditions: (1) native intact capsule and labrum, (2) 2- or 4-cm interportal capsulotomy (IPC), (3) labral tear, (4) T extension, (5) labral repair, (6) T extension repair, and (7) IPC repair. Each specimen was retested at 0° of flexion, 45° of flexion, and 45° of flexion with 15° of internal rotation.

RESULTS

A significantly higher distractive force was required to rupture the suction seal in the intact condition compared with IPC (P = .012; 95% confidence interval [CI], 4.9-42.4); IPC and labral tear (P = .002; 95% CI, 11.3-49.4); IPC, labral tear, and T extension (P = .001; 95% CI, 13.9-51.5); IPC, labral repair, and T extension (P < .001; 95% CI, 20.8-49.7); IPC, labral repair, and T extension repair (P = .002; 95% CI, 12.5-52.4); and IPC repair, labral repair, and T extension repair (P = .01; 95% CI, 5.8-46.1). The IPC condition required a higher distractive force in isolation than when combined with a labral tear (P = .14; 95% CI, 1.2-12.0), T extension (P = .005; 95% CI, 2.8-15.3), or labral repair (P = .002; 95% CI, 4.4-18.8).

CONCLUSIONS

The distractive resistance of an intact hip capsule and labrum was not restored once the soft tissues were violated, despite labral repair with a loop technique and capsular repair with interrupted figure-of-8 sutures.

CLINICAL RELEVANCE

Time-zero complete capsular repair with concomitant labral repair may not be adequate to restore distractive hip stability after hip arthroscopy, reinforcing the use of postoperative precautions in the early postoperative period.

Editorial Commentary: Arthroscopic Hip Labral Preservation Combined With Bony Correction and Capsular Closure Results in Improved Patient Outcomes

Hip labral reconstruction aims to replace an irreparable or insufficient labrum with the goal of restoring the native function of the labrum and thus contribute to hip preservation. Multiple studies have reported success and improved outcomes with labral reconstruction, both in primary and revision settings. The function of the labrum includes providing additional soft-tissue coverage of the femoral head and contributing to regulation of fluid dynamics within the hip joint through the "suction seal." Labral tears and insufficiency alter hip joint biomechanics, which could result in hip microinstability and joint degeneration. Yet, although labral reconstruction is better than a labral-deficient state, labral reconstruction does not restore native hip biomechanics when compared with the native intact labrum. However, concomitant procedures to address bony morphology, hip capsule, cartilage, and adhesions in the revision setting frequently are performed at the time of labral reconstruction, making the true effect of labral reconstruction unknown. Therefore, the labrum should be considered as one of many variables when evaluating individuals with hip pain, and surgeons who perform hip arthroscopy should ensure that appropriate patient selection and additional pathology are adequately addressed in the primary and revision settings.

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.

Magnetic Resonance Imaging Approximates Labral Width at the 9-, 12-, and 3-O'Clock Positions in the Setting of Revision Hip Arthroscopy

PURPOSE

To compare preoperative magnetic resonance imaging (MRI) and intraoperative measurements of labral width and determine whether MRI can reliably predict labral width in the setting of revision surgery.

METHODS

Patients who underwent revision hip arthroscopy with labral repair performed by a single surgeon from January 2008 to December 2015 were identified retrospectively from a prospectively collected database. The width of the labrum was measured intraoperatively at the time of surgery. Two orthopaedic surgeons performed labral width measurements on MRI scans at 3 standardized locations using the clock-face method. Interobserver and intraobserver reliabilities were calculated, and comparisons between intraoperatively measured labral widths and MRI measurements were performed.

RESULTS

Fifty-eight patients who underwent revision hip arthroscopy were enrolled in the study. The average labral width measurements at the 3-, 12-, and 9-o'clock positions were 7.4 mm (standard deviation [SD], 1.2 mm), 7.5 mm (SD, 1.4 mm), and 6.6 mm (SD, 1.2 mm), respectively, on MRI compared with 6.7 mm (SD, 2.1 mm), 6.5 mm (SD, 2.5 mm), and 7.0 mm (SD, 1.9 mm), respectively, when measured intraoperatively. The average intraoperative measurements were smaller than the MRI measurements at the 3-o'clock (P = .03) and 12-o'clock (P = .01) positions. The inter-rater intraclass correlation coefficients between the 2 surgeons exhibited good agreement (0.612) at the 3-o'clock position, fair agreement (0.498) at the 12-o'clock position, and poor agreement (0.171) at the 9-o'clock position. The positive predictive values of the MRI measurements were 72% at the 3-o'clock position, 68% at the 12-o'clock position, and 88% at the 9-o'clock position for identifying a labral width of 6 mm or greater.

CONCLUSIONS

The results of this study show that MRI-measured labral width and actual labral width measured at the time of revision arthroscopy are usually within 1 mm of each other.

LEVEL OF EVIDENCE

Level II, diagnostic study investigating diagnostic test.

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.

Acetabular Labral Reconstruction Does Not Demonstrate Superior Biomechanical Properties Compared to Labral Repair or Intact Native Labrum but Is Superior to Labral Excision: A Systematic Review of Cadaveric Studies

PURPOSE

To systematically review and compare biomechanical properties of labral reconstruction to labral repair, intact native labrum, and labral excision in cadaveric studies.

METHODS

A search of the PubMed and Embase databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Cadaveric studies focused on hip biomechanics related to intact labrum, labral repair, labral reconstruction, labral augmentation, and labral excision were included. Investigated parameters included biomechanical data measures, such as distraction force, distance to suction seal rupture, peak negative pressure, contact area, and fluid efflux. Review articles, duplicates, technique reports, case reports, opinion articles, articles written in a language other than English, clinical studies focusing on patient-reported outcomes, studies performed in animals, and articles with no abstract available were also excluded.

RESULTS

Fourteen cadaveric biomechanical studies were included that compared labral reconstruction to labral repair (4 studies), labral reconstruction to labral excision (4 studies); and evaluation of distractive force of the labrum (3 studies), the distance to suction seal rupture (3 studies), fluid dynamics (2 studies), displacement at peak force (1 study), and stability ratio (1 study). Data pooling was not performed because of methodological heterogenicity of the studies. Labral reconstruction did not outperform labral repair in restoring the hip suction seal or any other biomechanical property. Labral repair significantly prevented greater fluid efflux when compared to labral reconstruction. Labral repair and reconstruction improved the distractive stability of the hip fluid seal from the labral tear and labral excision stage, respectively. Furthermore, labral reconstruction demonstrated to have better biomechanical properties than labral excision.

CONCLUSIONS

In cadaveric studies, labral repair or intact native labrum was biomechanically more superior than labral reconstruction; however, labral reconstruction can restore acetabular labral biomechanical properties and was biomechanically superior to labral excision.

CLINICAL RELEVANCE

In cadaveric models, labral repair outperforms segmental labral reconstruction in preserving the hip suction seal; nonetheless, segmental labral reconstruction biomechanically outperforms labral excision at time 0.

Tissue Integration and Chondroprotective Potential of Acetabular Labral Augmentation with Autograft Tendon: Study of a Porcine Model

BACKGROUND

The aim of this study was to explore the tissue healing process and changes in articular cartilage following acetabular labral augmentation in a porcine model.

METHODS

The labrum was resected unilaterally from 10 o'clock to 1 o'clock on the capsular side in 36 pigs. Eighteen pigs underwent labral augmentation (AUG group) using autologous Achilles tendon. No additional procedures were performed in the remaining pigs (control group). The pigs were killed at 6, 12, or 24 weeks postoperatively for histological assessment and measurement of the inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in synovial fluid.

RESULTS

All autografts were well placed in the labral defect in the AUG group, and good integration of the autograft with the remnant chondrolabral junction was observed at 24 weeks; only scar tissue was observed in the control group at 6, 12, and 24 weeks. Fibrochondrocytes were concentrated at the transition between the autograft and native labrum at early time points, and the cells within the autograft labrum were predominantly fibrochondrocytes at 24 weeks. Rough and irregular articular cartilage surfaces were observed in 3 of the 6 samples in the AUG group at 24 weeks; the others appeared smooth. Focal cartilage erosion (predominantly in the acetabulum) occurred in all samples in the control group at 12 and 24 weeks. The Mankin score at 24 weeks was significantly lower in the AUG group than in the control group (mean [95% confidence interval]: 2.33 [1.06 to 3.6] versus 9 [8.06 to 9.94], p < 0.001). Likewise, the concentrations of all cytokines (in pg/mL) were significantly lower in the AUG group than in the control group at 24 weeks (IL-6: 166.6 [155.22 to 177.94] versus 245.9 [242.66 to 249.14], p < 0.001; IL-1β: 122.1 [116.4 to 127.83] versus 282.9 [280.29 to 285.51], p < 0.001; and TNF-α: 56.22 [53.15 to 59.29] versus 135 [131.66 to 138.24], p < 0.001).

CONCLUSIONS

Autograft tendon used for labral augmentation was able to integrate well with the native labrum, which may help to preserve the articular cartilage.

CLINICAL RELEVANCE

Labral augmentation with autograft tendon may be a feasible option in cases of viable labral remnants.

Durable Outcomes After Hip Labral Reconstruction at Minimum 5-Year Follow-Up: A Systematic Review

PURPOSE

To systematically review and report the mid- to long-term patient reported outcomes (PROs) following hip labral reconstruction.

METHODS

A literature search of the Pubmed, Embase, and Cochrane Library databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for clinical studies reporting mid- to long-term PROs at minimum five year follow-up following arthroscopic hip labral reconstruction. A quality assessment was performed using the Methodological Index of Non-Randomized Studies (MINORS) grading system. Data collection included study characteristics, demographics, indications, radiographic metrics, perioperative findings, surgical technique, baseline and most recent PROs, and subsequent surgeries.

RESULTS

Four studies met inclusion criteria, with 182 hips (age range, 27.9 to 38.7 years) undergoing labral reconstruction in primary and revision hip surgery with minimum five year follow-up. There were three level III studies and one level IV study, with an average MINORS score of 16.6. All studies cited labral tissue characteristics as a factor for surgical indications, including the quality and/or size of the labrum. Three studies performed segmental labral reconstructions, while another study utilized a circumferential technique. Varying grafts were selected, including hamstring autograft/allograft, ligamentum teres autograft, iliotibial band autograft, and tensor fascia lata autograft. All studies demonstrated improved PROs from baseline to most recent follow-up, with four studies reporting modified Harris Hip Score (mHHS) values that increased from baseline (range, 58.9 to 66.8) to most recent follow-up (range, 80.1 to 86.3). After labral reconstruction, rates of revision arthroscopy ranged from 4.8% to 13.3% and conversion to total hip arthroplasty ranged from 1.6% to 27%.

CONCLUSION

Improved PROs were observed in all studies at minimum 5-year follow-up, suggesting that labral reconstruction can offer durable results beyond short-term follow-up. While surgical indications for all studies included labral tissue characteristics, differing graft selection and surgical techniques were utilized across studies, limiting the ability to determine an optimal treatment approach.

Update on contribution of hip labral tears to hip pain: A narrative review

Hip labral tears are found in 22-55% of individuals with hip pain, but labral tears without cysts are usually not responsible for hip pain, which originates mostly from other structures than the torn labrum, like osteochondral, but also tendinous injuries (rectus femoris, gluteus minimus, iliopsoas) or capsulo-ligamentous tears (iliofemoral ligaments, ligament teres). Those lesions are mainly the consequences of underlying unrecognized functional acetabular dysplasia, and/or femoroacetabular impingements. Although the early repair of labral tears in young sportsmen induces a marked and lasting relief, and might delay the onset of osteoarthritis, the microinstability fostered by labral damages seems less important than underlying dysplasias/impingements. This narrative review details recent findings on: (i) the various mechanisms of pain associated with labral tears; (ii) few evidence for hip microinstability induced by isolated labral tears; (iii) how to best detect labral tears, both clinically (including through IROP test) and on imaging (MRI, MRA, computed tomography arthrography, ultrasound). Some authors suggested to use pull-out tests during surgery, but pulling of hips do not seem to increase much diagnostic performances of ultrasounds. Ultrasound-guided intra-articular and peri-articular injections may tell how often hip pain is exclusively induced by peri-capsular injuries secondary to the acetabular dysplasia/femoro-acetabular impingements already responsible for labral tears. Further works could tell whether labral repair, tendinous debridement, plication of capsule, and/or focal denervation, may induce lasting reliefs of pain induced by the chronic contraction of surrounding muscles (rectus femoris, gluteus minimus, psoas), whose deep aponeuroses mix with the superficial fibres of the thick hip capsule.

A Technique for Optimizing Hip Labrum Suction Seal With a Double-Limb, Oblique Inverting Mattress Stitch: The "X" and the "M" Configurations

Classic techniques in arthroscopic hip labral repair use circumferential or intrasubstance suture secured with anchors typically placed behind the labrum (capsular side). The primary goal of labral repair is to re-establish the hip suction seal and is often achieved via fixation techniques that invert viable labral tissue to restore or improve contact with the femoral head. Many repair techniques use only 1 suture limb either passed circumferentially around the labrum or passed in an intrasubstance manner, resulting in smaller purchase of labral tissue and lack of a strong inverting vector. In some cases, this may evert the labral tissue, compromising the suction seal. We describe a technique in which both suture limbs are passed in a mattress, figure-of-8 configuration, through the labral tissue, and tied on the capsular side to yield an inverting, double-limb repair. Therefore, each anchor results in a wider, more impactful repair footprint while reliably inverting the labral tissue.

Effect of Anchor Density on Functional Outcomes After Arthroscopic Hip Labral Repair

BACKGROUND

While labral repair has been widely adopted as the first line treatment for labral injury during hip arthroscopy, there is no widespread consensus on the procedural technique, including the number of anchors that should be used to avoid recurrent instability and revision surgery.

PURPOSE

To determine if anchor density can predict patient-reported outcomes after arthroscopic labral repair in the hip.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients aged 18 to 50 years who underwent primary hip arthroscopic surgery with labral repair between January 2011 and December 2016 were identified from a prospectively collected database. Exclusion criteria consisted of previous ipsilateral surgery, osteoarthritis (Tönnis grade >1), and severe cartilage defects (Outerbridge grade III/IV) or concomitant labral reconstruction, capsular reconstruction, or microfracture. Minimum 2-year patient-reported outcomes (modified Harris Hip Score [mHHS], Hip Outcome Score [HOS]-Activities of Daily Living [ADL], HOS-Sport Specific Subscale [SSS], 12-Item Short Form Health Survey [SF-12]), rates of achieving the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) for each score, revision surgery rate, and rate of conversion to total hip arthroplasty (THA) were compared based on anchor density (number of anchors per millimeter of labral tear).

RESULTS

A total of 634 hips (575 patients) with a mean age of 30.4 ± 9.5 years (range, 18.0-49.9 years) met inclusion criteria. The mean labral tear size was 31 ± 11 mm (range, 2-70 mm) with a median number of anchors used for labral repair of 3 (range, 1-7) and mean anchor density of 0.11 ± 0.08 anchors (range, 0.03-1.33) per millimeter of labral tear. Hips with a minimum 2-year follow-up (451/634 [71.1%]) had significant improvements on the mHHS, HOS-ADL, HOS-SSS, and SF-12 Physical Component Summary (P < .001 for all). There was no significant correlation detected between anchor density or number of anchors used and postoperative scores (correlation coefficient range, -0.05 to 0.17; P > .05 for all). The rate of revision surgery was 6.4% (28 patients), with 8 hips found to have labral tears and/or deficiency on revision. Additionally, 6 hips (1.3%) had to undergo THA at a mean of 3.6 ± 2.1 years (range, 2.0-5.5 years).

CONCLUSION

Anchor density did not have a correlation with postoperative outcomes, achieving the MCID or PASS, revision hip arthroscopic surgery, complications, or conversion to THA.

The Vascularization Course of Labral Autograft and Its Effect on Tissue Healing: Acetabular Labral Augmentation Versus Labral Reconstruction in a Porcine Model

BACKGROUND

The preservation of the native labral vascularization is assumed to be the potential advantage of acetabular labral augmentation, the effect of which remains unknown.

PURPOSE

To identify the vascular distribution within the labral autograft and its effect on the healing process between labral augmentation (AUG) and reconstruction (RECON) in a porcine model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 36 pigs randomly underwent unilateral labral augmentation or reconstruction (AUG group, n = 18; RECON group, n = 18). The pigs were randomly sacrificed at 6, 12, and 24 weeks postoperatively. The labral autografts were harvested for macroscopic evaluation and histologic assessment. The labral autograft was zoned into 2 halves to observe the vascular distribution: the capsular half (zone I) and the articular half (zone II). Each zone was divided into 2 parts: the peripheral part (IA and IIA) and the part attached to the acetabulum (IB and IIB).

RESULTS

At 6 weeks, there existed more vascular ingrowth in zone I, whereas zone IIB appeared nearly avascular in both groups. At 12 weeks, the area with the greatest vascularity was zone II in the RECON group and zone IA in the AUG group. The vascularity was concentrated at zones IA and IIA in both groups at 24 weeks. The labral autografts were hypertrophic with sufficient filling of the labral defect in both groups at 6 weeks. At 12 weeks, an insufficient volume of the articular half was observed in 3 of 6 labral autografts in the RECON group, while all autografts remained well integrated with the chondrolabral junction in the AUG group. At 24 weeks, unsatisfactory merging of the labral autograft with the cartilage at the articular side was found in 2 of 6 labral autografts in the RECON group, which was not observed in the AUG group despite the sufficient volume of autografts labrum in both groups.

CONCLUSION

Slow vascular ingrowth within the articular half might account for the poor healing of the reconstructed labral autograft. Labral augmentation provides the possibility of better tissue healing because of the preservation of the original chondrolabral junction compared with labral reconstruction.

CLINICAL RELEVANCE

Labral augmentation might be a feasible alternative to labral reconstruction under the condition of viable labral remnants.

Arthroscopic Hip Capsular Reconstruction Using Iliotibial Band Allograft as a Salvage Option for Unrepairable Capsular Defects Demonstrates Good Survivorship and Improved Patient-Reported Outcomes

PURPOSE

To describe patient outcomes 3 to 5 years after arthroscopic hip capsule reconstruction.

METHODS

Between January 2007 and December 2016, patients aged 18 to 50 years who underwent arthroscopic hip capsular reconstruction using an Iliotibial band allograft by the senior author and had minimum of 3-year follow-up were identified. Patients were excluded if they had previous open hip surgery, advanced osteoarthritis (Tönnis grade >2), significant acetabular dysplasia (lateral center edge angle <20°), avascular necrosis, or Legg-Calve-Perthes disease. Outcome scores including the Hip Outcome Score (HOS)-Activities of Daily Living scale, modified Harris Hip Score, HOS-Sports scale, SF-12, and Western Ontario & McMaster Universities Osteoarthritis Index were compared in addition to failure rate, revision rate, and patient satisfaction rate with the outcome (range, 1-10). All patients were assessed by the senior author pre- and postoperatively.

RESULTS

Thirty-nine patients met the inclusion criteria. The mean age of the cohort was 32 ± 10 years, with 6 male and 33 female patients. The average number of previous hip arthroscopy surgeries was 2 ± 1. Six patients (15%) converted to total hip arthroplasty at an average of 2.1 years (range 7 months to 6 years) following capsular reconstruction. Four patients required revision hip arthroscopy after the arthroscopic capsular reconstruction. All arthroscopic revisions occurred in female patients with the primary intraoperative finding of capsulolabral adhesions at the time of revision. At mean follow-up of 4.3 years (range 3-6.8 years), the 29 patients who did not require subsequent surgery had significant improvements from preoperatively to postoperatively in HOS-Activities of Daily Living and HOS-Sport with 90% reaching minimal clinically important difference. All other scores showed significant improvement. Survival for patients not requiring total hip arthroplasty was 86% at 3 years, with a mean survival of 5.7 years (95% confidence interval 4.97-6.4).

CONCLUSIONS

Arthroscopic hip capsular reconstruction with iliotibial band allograft is a successful treatment option for patients with symptomatic capsular defects, demonstrating improved patient-reported outcomes maintained at mean follow-up time of 4 years. This technique offers restoration of the anatomic structure and function of the capsular ligaments to improve pain and instability.

LEVEL OF EVIDENCE

IV, case series.

Minimum 5-Year Outcomes After Primary Segmental Labral Reconstruction for Irreparable Labral Tears in the Hip With Hamstring Grafts: With a Subanalysis Comparing Autograft Versus Allograft

BACKGROUND

Comparable short-term outcomes have been obtained using hamstring allografts versus autografts after primary segmental labral reconstruction (SLR). Midterm results have not yet been determined.

PURPOSE

(1) To evaluate minimum 5-year patient-reported outcome (PRO) scores in patients who underwent primary SLR with hamstring grafts in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare the outcomes of hamstring autografts versus allografts in a subanalysis using propensity-matched groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospectively collected data were retrospectively reviewed for patients who underwent primary hip arthroscopy between September 2010 and November 2015. Patients were included if they underwent SLR using hamstring autografts or allografts and had preoperative and minimum 5-year PROs. The exclusion criteria were previous ipsilateral hip surgery or conditions, dysplasia, or Tönnis grade >1. Patients with autograft SLR were propensity matched 1 to 1 based on age, sex, and body mass index (BMI) to patients who underwent SLR using hamstring allografts. The minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) were calculated.

RESULTS

Overall, 48 patients (N = hips 48) were eligible to be included in this study, and 41 patients (n = 41 hips [85.4%]) had a minimum 5-year follow-up reporting significant improvements in all PROs. Within the entire cohort, 9.8% required a secondary arthroscopy, with a mean time of 19 ± 1.8 months, and survivorship was 82.9%. Of the 41 included patients, 15 underwent an SLR with a hamstring autograft and were matched to 15 patients with labral reconstruction using a hamstring allograft. Groups were similar for sex (P > .999), age (P = .775), and BMI (P = .486). The mean follow-up times were 80.8 ± 25.5 and 66.1 ± 8.3 months (P = .223) for the autograft and allograft groups, respectively. Baseline PROs, preoperative radiographic measurements, surgical findings, and intraoperative procedures were similar. The groups achieved significant and comparable improvements for all PROs (P < .0001), satisfaction (P = .187), and the rate of achieving the MCID and the PASS. However, a tendency for higher postoperative PROs favoring allograft reconstruction was found.

CONCLUSION

At a minimum 5-year follow-up, patients who underwent primary arthroscopic SLR in the context of FAIS and irreparable labra, with either autograft or allograft hamstring tendons, reported significant improvements and comparable postoperative scores for all PROs, patient satisfaction, MCID, and PASS.

Osteochondroplasty Benefits the Pragmatic Patient With Femoroacetabular Impingement: Analysis From the Embedded Prospective Cohort of the Femoroacetabular Impingement RandomiSed Controlled Trial (FIRST)

PURPOSE

To determine whether arthroscopic osteochondroplasty demonstrated effectiveness in a pragmatic femoroacetabular impingement patient population embedded within FIRST (the Femoroacetabular Impingement RandomiSed controlled Trial).

METHODS

All cohort patients were not randomized and were followed prospectively with a follow-up assessment protocol identical to that in FIRST. The primary outcome was hip pain using a 100-point visual analog scale. Secondary outcomes included hip function (Hip Outcome Score, International Hip Outcome Tool-12), health utility (EuroQol 5 Dimensions), and health-related quality of life (Short Form-12) at 12 months, as well as operatively and nonoperatively treated hip complications at 24 months. We performed multivariable regressions to compare these outcomes between 3 groups of patients: (1) those randomized to lavage in FIRST, (2) those randomized to osteochondroplasty in FIRST, and (3) those who received osteochondroplasty as part of the cohort study.

RESULTS

All groups had improvements across all questionnaire outcomes from baseline to 12 months, with no significant differences. There were significantly more reoperations in the lavage trial group compared with those in the embedded cohort (adjusted odds ratio [aOR] 3.08; 95% confidence interval [CI] 1.23-7.73; P = .016). There were significantly more nonoperatively treated hip complications in the lavage trial group and in the osteochondroplasty trial group when compared with those in the embedded cohort (aOR 3.81; 95% CI 1.19-12.17; P = .024 and aOR 4.55; 95% CI 1.43-14.42; P = .010, respectively).

CONCLUSIONS

Hip arthroscopic osteochondroplasty and lavage led to improvement in hip pain, function, and health-related quality of life at 12 months across both randomized controlled trial (RCT) and cohort patients. The pragmatic cohort receiving osteochondroplasty had (1) significantly fewer complications than RCT patients, (2) significantly less reoperations than RCT patients randomized to arthroscopic lavage, and (3) fewer, although nonsignificant, reoperations than RCT osteochondroplasty patients.

LEVEL OF EVIDENCE

II, therapeutic.

Allograft Labral Reconstruction of the Hip: Expanding Evidence Supporting Greater Utilization in Hip Arthroscopy

Purpose of Review

The current review investigates outcomes and failure rates associated with arthroscopic circumferential allograft labral reconstruction of the hip, both as a revision and primary procedure in treating femoroacetabular hip impingement and labral-related pathology.

Recent Findings

Numerous studies within the last decade have demonstrated excellent patient-reported outcomes, high rates of return-to-play in athletes, and low failure rates in patients having undergone arthroscopic circumferential allograft labral reconstruction of the hip. Removal of chronically diseased and injured labral tissue can eliminate a significant pain-generator from the hip joint. Additionally, circumferential reconstruction of the labrum restores the hoop fiber strength and fluid seal akin to what would be seen with native, healthy labral tissue. Recent research has shown that arthroscopic circumferential allograft labral reconstruction may be used not only in the revision setting, but as a primary procedure. Circumferential labral reconstruction should be considered when a surgeon feels that the labrum is irreparable or has failed previous repair.

Summary

Arthroscopic circumferential allograft labral reconstruction of the hip can be utilized as treatment option not only in revision settings, but also in primary treatment for femoroacetabular impingement and labral pathology

Minimum 2-Year Outcomes Following Arthroscopic Hip Labral Reconstruction in Adolescents and Young Adults

BACKGROUND

Labral repair is generally preferred when facing labral tears. When an irreparable labral tear in the context of femoroacetabular impingement syndrome is present, arthroscopic labral reconstruction has been proven to be a valid option for labral restoration. However, data on this procedure for the adolescent population is scarce. The purpose of the present study was to report minimum 2-year follow-up patient-reported outcome measures (PROMs) on adolescents and young adults following arthroscopic acetabular labral reconstruction.

METHODS

Data were prospectively collected and retrospectively reviewed on adolescents and young adults who underwent hip arthroscopy between March 2009 and June 2018. Inclusion criteria were labral reconstruction, baseline and minimum 2-year follow-up PROMs. Patients were excluded if they were unwilling to participate in the study, had Tönnis grade >1, or dysplasia.

RESULTS

Twenty-three hips (22 patients) that underwent labral reconstruction were included. Ten hips (10 patients) underwent primary labral reconstruction, and 13 hips (12 patients) underwent revision reconstruction. The mean age was 19.3 years and 56.5% of patients were males. All patients improved significantly at minimum 2 years for all PROMs (P<0.001) with high satisfaction. Patients in both groups demonstrated improvement for all PROMs, patient satisfaction, and a rate of achieving the minimal clinically important difference.

CONCLUSION

Arthroscopic labral reconstruction in adolescents and young adults demonstrated significant improvement and high patient satisfaction at minimum 2-year follow-up in the setting of irreparable labral tear. Favorable outcomes, high patient satisfaction, and high achievement rate for the minimal clinically important difference were obtained following labral reconstruction in this population the primary and revision scenarios.

LEVEL OF EVIDENCE

Level IV, case-series.

Endoscopic Shelf Procedure and Ischiofemoral Decompression with Arthroscopic Acetabular Labral Reconstruction: A Case Report

CASE

A 43-year-old female patient complained of pain in the right hip. The diagnoses of hip dysplasia, ischiofemoral impingement (IFI), femoroacetabular (FAI) cam-type morphology, and labral tear were made. The patient underwent hip arthroscopy with labral reconstruction for an irreparable labral tear and cam-morphology correction, and hip endoscopy for shelf procedure and ischiofemoral decompression. Favorable outcomes were reported at 1-year follow-up.

CONCLUSION

Hip arthroscopy for FAI cam-type morphology with labral reconstruction and concomitant hip endoscopy for shelf and ischiofemoral decompression seem to be safe for the treatment of active young adult patients with FAI cam-type morphology, irreparable labral tear, dysplasia, and IFI diagnoses. Nevertheless, the results presented should not be extrapolated as this is a case report.

Short-term patient-reported outcomes following concomitant hip arthroscopy and the endoscopic modified shelf procedure for the treatment of acetabular dysplasia and intra-articular pathology

The shelf procedure is a treatment of acetabular dysplasia, with the aim of increasing weight-bearing acetabular coverage. Although several shelf techniques have been described, the endoscopic procedure with concomitant hip arthroscopy is a new, less invasive alternative. Outcomes following this procedure are scarce. The purpose of this study was to report short-term patient-reported outcomes (PROs) following concomitant hip arthroscopy and endoscopic modified shelf procedure in the setting of acetabular dysplasia and labral tears. Patients that met extraordinarily selective surgical indications and underwent the abovementioned surgery between February 2016 and October 2019 and had minimum 1-year follow-up were included. There were five females with a mean age of 40.18 ± 5.05 years and follow-up of 21.55 ± 8.68 months. The lateral center-edge angle increased from 15.80° to 23.20° (P = 0.003), and vertical center-edge angle increased from 16.60° to 23.60° (P < 0.001). The Tönnis angle decreased from 15.40° to 3.74° (P < 0.001). The alpha angle decreased from 58.46° to 40.70° (P < 0.001). PROs demonstrated significant improvement at latest follow-up (modified Harris Hip Score, P = 0.042; Non-Arthritic Hip Score, P < 0.001; Hip Outcome Score–Sports Specific Subscale, P = 0.035; Visual Analog Scale, P < 0.001; International Hip Outcome Tool-12, P = 0.043), and satisfaction was 8.60 ± 0.89. No secondary surgeries were reported. Concomitant hip arthroscopy and endoscopic modified shelf procedure appears to be a safe and effective procedure for patients with acetabular dysplasia and labral tears yielding favorable outcomes and satisfaction at short-term follow-up.

The Hip Suction Seal, Part I: The Role of Acetabular Labral Height on Hip Distractive Stability

BACKGROUND

The acetabular labrum has been found to provide a significant contribution to the distractive stability of the hip. However, the influence of labral height on hip suction seal biomechanics is not known.

HYPOTHESIS

The smaller height of acetabular labrum is associated with decreased distractive stability.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 23 fresh-frozen cadaveric hemipelvises were used in this study. Hips with acetabular dysplasia or femoroacetabular impingement-related bony morphologic features, intra-articular pathology, or no measurable suction seal were excluded. Before testing, each specimen's hip capsule was removed, a pressure sensor was placed intra-articularly, and the hip was fixed in a heated saline bath. Labral size was measured by use of a digital caliper. Maximum distraction force, distance to suction seal rupture, and peak negative pressure were recorded while the hip underwent distraction at a rate of 0.5 mm/s. Correlations between factors were analyzed using the Spearman rho, and differences between groups were detected using Mann-Whitney U test.

RESULTS

Of 23 hips, 12 satisfied inclusion criteria. The maximum distraction force and peak negative pressure were significantly correlated (R = -0.83; P = .001). Labral height was largely correlated with all suction seal parameters (maximum distraction force, R = 0.69, P = .013; distance to suction seal rupture, R = 0.55, P = .063; peak negative pressure, R = -0.62, P = .031). Labral height less than 6 mm was observed in 5 hips, with a mean height of 6.48 mm (SD, 2.65 mm; range, 2.62-11.90 mm; 95% CI, 4.80-8.17 mm). Compared with the 7 hips with larger labra (>6 mm), the hips with smaller labra had significantly shorter distance to suction seal rupture (median, 2.3 vs 7.2 mm; P = .010) and significantly decreased peak negative pressure (median, -59.3 vs -66.9 kPa; P = .048).

CONCLUSION

Smaller height (<6 mm) of the acetabular labrum was significantly associated with decreased distance to suction seal rupture and decreased peak negative pressure. A new strategy to increase the size of the labrum, such as labral augmentation, could be justified for patients with smaller labra in order to optimize the hip suction seal.

CLINICAL RELEVANCE

The height of the acetabular labrum is correlated with hip suction seal biomechanics. Further studies are required to identify the clinical effects of labral height on hip stability.