No regeneration of the human acetabular labrum after excision to bone

Can the Acetabular Labrum Be Reconstructed With a Meniscal Allograft? An In Vivo Pig Model

BACKGROUND

No single graft type has been shown to have a benefit in acetabular labral reconstruction. The native labrum and lateral meniscus share many similarities, suggesting that the meniscus may be a promising source of graft material in labral reconstruction.

QUESTIONS/PURPOSES

Using a pig model, we sought to evaluate the healing process of fresh-frozen meniscus allograft for acetabular reconstruction by assessing (1) MRI and macroscopic observations of the meniscus allograft; (2) histologic appearance and immunohistologic evaluation of the meniscus allograft, native meniscus, and labrum; (3) microscopic assessment of the native labrum and meniscus via scanning electron microscopy; and (4) biomechanical assessment of tensile properties.

METHODS

Twelve skeletally mature male miniature Bama pigs (24 hips) were randomly divided into two groups: labral defect group (control) and lateral meniscus allograft group. The selection of Bama pig specimens was based on the similarity of their acetabular labrum to that of the human acetabular labrum, characterized by the presence of fibrocartilage-like tissue lacking blood vessels. The pigs underwent bilateral hip surgery. Briefly, a 1.5-cm-long section was resected in the anterior dorsal labrum, which was left untreated or reconstructed using an allogeneic lateral meniscus. The pigs were euthanized at 12 and 24 weeks postoperatively, and then evaluated by macroscopic observations and MRI measurement to assess the extent of coverage of the labral defect. We also performed a histologic analysis and immunohistologic evaluation to assess the composition and structure of meniscus allograft, native labrum, and meniscus, as well as scanning electron microscopy assessment of the microstructure of the native labrum and meniscus and biomechanical assessment of tensile properties.

RESULTS

Imaging measurement and macroscopic observations revealed that the resected area of the labrum was fully filled in the lateral meniscus allograft group, whereas in the control group, the labral defect remained at 24 weeks. The macroscopic scores of the meniscus allograft group (8.2 ± 0.8) were higher than those of the control groups (4.8 ± 1.0) (mean difference 3.3 [95% CI 1.6 to 5.0]; p < 0.001). Moreover, in the meniscus allograft group, histologic assessment identified fibrocartilage-like cell cluster formation at the interface between the graft and acetabulum; cells and fibers arranged perpendicularly to the acetabulum and tideline structure that were similar to those of native labrum could be observed at 24 weeks. Immunohistochemical results showed that the average optical density value of Type II collagen at the graft-acetabulum interface was increased in the meniscus allograft group at 24 weeks compared with at 12 weeks (0.259 ± 0.031 versus 0.228 ± 0.023, mean difference 0.032 [95% CI 0.003 to 0.061]; p = 0.013). Furthermore, the tensile modulus of the lateral meniscus allograft was near that of the native labrum at 24 weeks (54.7 ± 9.9 MPa versus 63.2 ± 11.3 MPa, mean difference -8.4 MPa [95% CI -38.3 to 21.4]; p = 0.212).

CONCLUSION

In a pig model, lateral meniscus allografts fully filled labral defects in labral reconstruction. Regeneration of a fibrocartilage transition zone at the graft-acetabulum interface was observed at 24 weeks.

CLINICAL RELEVANCE

The use of an autograft meniscus for labral reconstruction may be a viable option when labral tears are deemed irreparable. Before its clinical implementation, it is imperative to conduct a comparative study involving tendon grafts, which are extensively used in current clinical practice.

The Cartilage Protective Effect of Labrum Reconstruction Using Meniscus Allograft Compared with Labrum Resection in a Porcine Model

PURPOSE

This study aimed to verify the femoral head cartilage protective effect of labral reconstruction in a porcine model.

METHODS

Twelve pigs (24 hips) were divided into 3 groups: labrum defect group, lateral meniscus (LM) allograft group, and LM allograft wrapped with acellular peritoneum matrix (LM-APM) group before undergoing bilateral hip surgery. The pigs were sacrificed at 12 and 24 weeks postoperatively, while the femoral head cartilage was retrieved and then subjected to imaging measurement, macroscopic observations, and biomechanical and histological assessment.

RESULTS

Imaging measurement and macroscopic observations revealed that the defect area of the labrum was filled in LM and LM-APM allograft groups after 24 weeks, whereas the labrum defect remained at 24 weeks in the control group. The femoral head cartilage corresponding to the area of labral resection in the labral defect group had worse macroscopic Osteoarthritis Research Society International (OARSI) scores, uneven and discontinuous cartilage on hematoxylin and eosin (H&E) staining and Safranin O staining, decreased histopathology OARSI Osteoarthritis Cartilage Histopathology Assessment System (OOCHAS) scores, and decreased elastic modulus and hardness at 12 and 24 weeks after surgery compared with the meniscus allograft groups.

CONCLUSION

This study demonstrated that the LM allograft with or without APM for labral reconstruction had a chondroprotective effect on the femoral head in a porcine model.

Magnetic Resonance Arthrographic Findings After Hip Labrum Resection Versus Refixation

The aim of this study was to evaluate whether new tissue formation occurs after labral debridement/excision, and, if so, which morphological features are typical for a neo-labrum. The authors further compared the findings after labrum resection with those seen after labrum refixation. Patients with femoroacetabular impingement who underwent hip arthroscopy or surgical hip dislocation to address a labrum pathology were retrospectively included, and postoperative magnetic resonance arthrography studies were assessed. Forty-two patients had undergone either labrum resection (n=25) or refixation (n=17), performed arthroscopically (47.6%) or via surgical hip dislocation (52.4%). In the subgroup of patients after debridement/resection, there was anterosuperior/superior scar tissue in 83.5%, with amorphous configuration in 92%, irregular surface in approximately two-thirds of the cases, and a mean±SD thickness of 7.0±2.7 mm. A labrum-like shape of the scar plate was seen in 7.7%. Regarding the subgroup of patients who had undergone labral refixation, an irregular or rounded labrum shape was noted in 26.5% and 51.3% of cases, respectively, with a triangular shape in less than one-fourth of cases. Labrum re-tears (35.7%) were mainly observed at the base (71.7%), rather than within the labral substance (28.4%). New tissue formation can be observed in the majority of cases after excision of the hip labrum, with amorphous and irregular surface configuration compared with a native labrum. This new tissue should therefore be referred to as scar tissue rather than as neo-labrum. Whether scar tissue is inferior to a refixed labrum needs to be further elucidated in follow-up studies. [Orthopedics. 2021;44(4):e607-e613.].

[Research progress in arthroscopic treatment of acetabular labrum injury]

Objective

To review the surgical methods of arthroscopy in the treatment of acetabular labrum injury, and to provide reference for clinical treatment.

Methods

The literature about the surgical methods and clinical results of hip arthroscopy in the treatment of acetabular labrum injury was reviewed and analyzed.

Results

In the early stages of hip arthroscopy, the removal of the torn labrum is the primary treatment option. The current principles of treatment are based on the specific circumstances of a torn labrum, including acetabular labrum debridement, acetabular labrum repair, acetabular labrum reconstruction, and acetabular labrum augmentation.

Conclusion

Hip arthroscopy has become the preferred technique for the treatment of acetabular labrum injury. Labral repair is still the first choice, and labral reconstruction is used when acetabular labrum injury cannot be repaired.

Indications and Outcomes for Arthroscopic Hip Labral Reconstruction With Autografts: A Systematic Review

Background: The acetabular labrum plays a major role in hip function and stability. The gold standard treatment for labral tears is labral repair, but in cases where tissue is not amenable to repair, reconstruction has been demonstrated to provide superior outcomes compared to debridement. Many types of grafts have been used for reconstruction with good to excellent outcomes. Autograft options include iliotibial band (ITB), semitendinosus, and indirect head of the rectus femoris tendon, while allografts have included fascia lata and gracilis tendon allografts.

Questions/Purposes: As allografts are not always readily available and have some inherent disadvantages, the aims of this systematic review were to assess (1) indications for labral reconstruction and (2) summarize outcomes, complications, and reoperation rates after arthroscopic labral reconstruction with autografts.

Methods: A systematic review of the literature was performed using six databases (PubMed, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Scopus, and Google Scholar) to identify studies reporting outcomes for arthroscopic labral reconstruction utilizing autografts, with a minimum follow-up of 1 year. Study design, patient demographics, autograft choice, complications, donor site morbidity, reoperation rates, conversion to arthroplasty, and patient reported outcomes were extracted and reported.

Results: Seven studies were identified for inclusion with a total of 402 patients (173 females, age range 16–72, follow-up range 12–120 months). The most commonly reported functional outcome score was the modified Harris Hip Score (mHHS), which was reported in six of seven studies. Preoperative mHHS ranged from 56 to 67.3 and improved postoperatively to a range of 81.4–97.8. Conversion to total hip arthroplasty and reoperation rates ranged from 0 to 13.2% and 0 to 11%, respectively. The most common indication for labral reconstruction was an irreparable labrum. Autografts utilized included ITB, hamstring tendons, indirect head of rectus femoris, and capsular tissue.

Conclusions: Arthroscopic autograft reconstruction of the acetabular labrum results in significant improvement in the short- and mid-term patient reported outcomes, for properly selected patients presenting with pain and functional limitation in the hip due to an irreparable labral injury.

Labral debridement, repair and reconstruction: current concepts

Proper treatment of labral pathology is under debate. The treatments currently available to hip surgeons are: conservative treatment, labral debridement, repair and reconstruction while concomitantly addressing bony dysmorphisms. The data available to assist surgeons to make the correct treatment decisions are inconclusive. In this current concepts review, the technical aspects and currently available literature to assist in the decision-making process with these treatment modalities are reviewed. The exact indications for each procedure are still up for debate and ongoing research will better define the ideal patients for each procedure. The purpose of this narrative review was to discuss the current research on debridement, repair and reconstruction as well as the techniques that are currently reported in the literature.

Selective Debridement With Labral Preservation Using Narrow Indications in the Hip: Minimum 5-Year Outcomes With a Matched-Pair Labral Repair Control Group

BACKGROUND

Arthroscopic labral debridement in the hip can be an effective treatment for labral tears but has demonstrated inferior outcomes compared with labral repair. Thus, the role for labral debridement has become unclear. Hypothesis/Purpose: The purpose was to evaluate the outcomes of a selective debridement with labral preservation (SDLP) group with a minimum 5-year follow-up. It was hypothesized that, with narrow indications, SDLP would produce statistically improved patient-reported outcome (PRO) scores, comparable with those of a matched-pair labral repair control group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were collected on all patients undergoing primary hip arthroscopic surgery between February 2008 and September 2011. Exclusion criteria were acetabular or femoral head Outerbridge grade 4 chondral damage, preoperative Tnnis grade ≥2, workers' compensation claims, previous hip conditions, severe dysplasia (lateral center-edge angle <18°), or previous ipsilateral hip surgery. Patients who underwent arthroscopic labral debridement and had preoperative and minimum 5-year PRO scores, including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), and Hip Outcome Score-Sports-Specific Subscale (HOS-SSS) as well as the visual analog scale (VAS) for pain, were included. In a nested matched-pair comparison, the SDLP group was matched 1:1 to an arthroscopic labral repair control group based on age ±5 years, body mass index ±5 kg/m², sex, and Seldes tear type.

RESULTS

One hundred twenty-five hips were eligible for inclusion, of which 101 (80.8%) hips had a minimum 5-year follow-up. All PRO scores were significantly improved ( P < .001) at latest follow-up (mHHS, 63.4 to 82.4; NAHS, 57.4 to 83.6; HOS-SSS, 44.2 to 74.5). The mean VAS score decreased from 5.8 to 2.3 ( P < .001). The mean patient satisfaction score was 8.1. Four (4.0%) patients underwent second-look arthroscopic surgery (mean, 18.5 months), and 14 (13.9%) patients converted to total hip arthroplasty (mean, 46.9 months). In the matched-pair comparison, 69 in the SDLP group were matched 1:1 with those undergoing labral repair. Outcomes at latest follow-up of the SDLP group were comparable with those of the control group, respectively: mHHS, 83.0 vs 86.1 ( P = .084); NAHS, 85.0 vs 85.4 ( P = .415); HOS-SSS, 74.8 vs 76.8 ( P = .219); VAS, 2.3 vs 2.0 ( P = .277); international Hip Outcome Tool-12 (iHOT-12), 73.8 vs 76.4 ( P = .136); Short Form Health Survey-12 (SF-12) mental, 57.4 vs 55.1 ( P = .031); SF-12 physical, 48.7 vs 48.9 ( P = .357); Veterans RAND Health Survey-12 (VR-12) mental, 61.6 vs 59.8 ( P = .160); VR-12 physical, 50.1 vs 50.2 ( P = .340); and patient satisfaction, 8.0 vs 8.3 ( P = .211).

CONCLUSION

In select cases of stable labral tears, SDLP may allow the preservation of a functional labrum. At a minimum 5-year follow-up, SDLP using narrow indications produced favorable outcomes comparable with a matched-pair labral repair group.

Labral augmentation with ligamentum capitis femoris: presentation of a new technique and preliminary results

Preservation of an intact labrum and reconstruction of a deficient or worn acetabular labrum are accepted techniques in modern hip surgery. If the remaining labrum is very thin, its intact tip can be preserved and its volume restored with a ligamentum teres graft. Technique and preliminary results of this augmentation technique are presented. Labral augmentation was performed in 16 hips (11 rights) in 16 patients (7 males, mean age 29 years) during surgical dislocation for treatment of femoroacetabular impingement. The acetabular index, lateral center edge angle, asphericity angle and acetabular retroversion index were determined on preoperative X-rays and magnetic resonance imaging. The pre- and postoperative Merle d'Aubigné and Postel score (MdA) was calculated and the Oxford Hip Score (OHS) obtained after 1 year. There were seven Grade 1 and nine Grade 0 hips (Tönnis classification). Mean lateral center edge was 29°. The mean acetabular index was 1.85°. Mean asphericity angle was 62.5°. Mean acetabular retroversion index was 23.4%. Mean MdA improved from 14.5 preoperatively to 17 at 1 year (P < 0.0001). Mean OHS after 1 year was 42. Previous surgery was a risk factor for inferior results: OHS was 44.5 in hips without versus 26 in hips with previous surgery. Mean MdA improved from 15 to 17.5 in patients without previous surgery versus 14 to 16 for the group with previous surgery. Augmentation of the labrum using ligamentum teres shows good clinical results after 1 year. Patients with previous hip surgery had inferior results.

Arthroscopic Labral Base Repair in the Hip: 5-Year Minimum Clinical Outcomes

BACKGROUND

Arthroscopic labral base repair (LBR) in the hip is a previously described technique designed to restore the native functional anatomy of the labrum by reproducing its seal against the femoral head. LBR has been shown to have good short-term outcomes. Hypothesis/Purpose: The purpose was to evaluate clinical outcomes of an LBR cohort with a minimum 5-year follow-up. It was hypothesized that patients who underwent LBR would continue to have significant improvement from their preoperative scores and maintain scores similar to their 2-year outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data for patients undergoing primary hip arthroscopic surgery with LBR from February 2008 to May 2011 with a minimum 5-year follow-up were prospectively collected and retrospectively reviewed. Patients with preoperative Tonnis osteoarthritis grade ≥2, previous hip conditions (slipped capital femoral epiphysis, avascular necrosis, Legg-Calv-Perthes disease), severe dysplasia (lateral center-edge angle <18°), or previous ipsilateral hip surgery were excluded. Statistical equivalence tests evaluated patient-reported outcomes (PROs) including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale (HOS-SSS), visual analog scale (VAS) for pain, and patient satisfaction (0-10 scale; 10 = very satisfied).

RESULTS

Of the 70 patients (74 hips) who met inclusion and exclusion criteria, 60 (85.7%) patients (64 hips) were available at a minimum 5-year follow-up. All PRO scores significantly improved from preoperative values with a mean follow-up of 67.8 ± 7.4 months (range, 60.0-89.7 months). The mean mHHS increased from 64.4 ±13.8 to 85.3 ± 17.7 ( P < .001), the mean NAHS from 63.7 ± 17.0 to 87.0 ± 14.7 ( P < .001), and the mean HOS-SSS from 47.1 ± 23.2 to 76.5 ± 25.9 ( P < .001). The mean VAS score decreased from 5.9 ± 2.4 to 2.0 ± 2.1 ( P < .001). The mean patient satisfaction score was 8.1 ± 2.0. The improvement in PRO scores was sustained from 2- to 5-year follow-up. At 2 and 5 years, survivorship rates were 96.9% and 90.6%, respectively, and the respective secondary arthroscopic surgery rates were 10.9% (7/64) and 17.2% (11/64).

CONCLUSION

At a minimum 5-year follow-up, arthroscopic LBR continued to be a successful procedure and valid technique based on 3 PROs, the VAS, patient satisfaction, and survivorship. Significantly improved outcome scores were maintained compared with preoperative values and showed no signs of deterioration from the 2-year scores. The long-term survivorship of hip arthroscopic surgery has yet to be determined; however, these midterm results demonstrate the rates of additional procedures (both secondary arthroscopic surgery and conversion to total hip arthroplasty), that may be necessary after 2 years.

The current situation in hip arthroscopy

Hip arthroscopy is an evolving surgical technique that has recently increased in popularity.

Although femoroacetabular impingement was an important launch pad for this technique, extra-articular pathology has been described through hip endoscopy.

Good clinical results in the medium term will allow improvements in this technique and increase its indications.

Cite this article: EFORT Open Rev 2017;2:58-65. DOI: 10.1302/2058-5241.2.150041

Acetabular Labral Debridement/Segmental Resection Versus Reconstruction in the Comprehensive Treatment of Symptomatic Femoroacetabular Impingement: A Systematic Review

PURPOSE

To perform a systematic review comparing outcomes of labral debridement/segmental resection with labral reconstruction as part of a comprehensive treatment strategy for femoroacetabular impingement.

METHODS

A systematic review was conducted according to established PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using defined inclusion and exclusion criteria. The study groups were divided into labral debridement/segmental resection (group 1) and labral reconstruction (group 2). Multiple search engines were queried (PubMed, Medline) for this analysis.

RESULTS

After an exhaustive search of the available literature, 20 publications were included. Twelve studies explored outcomes after labral debridement/resection in a total of 400 hips, whereas 7 studies reported on outcomes after labral reconstruction in a total of 275 hips. One additional matched-pair control study compared labral resection (22 hips) with reconstruction (11 hips). The surgical intervention was a revision in 0% to 100% for group 1 versus 5% to 55% for group 2. A direct anterior approach was not performed in group 2, and cam-type impingement appeared to make up a larger percentage of group 1. The Tönnis grade ranged from 0 to 1 for group 1 versus 0.3 to 1.1 for group 2. Joint replacements were performed in 0% to 30% and 0% to 25%, respectively. The modified Harris Hip Score was the most widely used patient-reported outcome measure and suggested that labral reconstruction was not inferior to labral debridement/segmental resection.

CONCLUSIONS

Clinical outcomes after labral debridement/segmental resection versus labral reconstruction were found to be comparable. In the setting of unsalvageable labral pathology, labral reconstruction was used more frequently as a revision option whereas debridement may be more commonly used in the index setting.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I, III, and IV studies.

Anatomic Labral Repair in the Hip Using a Knotless Tensionable Suture Anchor

To perform a proper labral repair, most surgeons use anchors to secure the labrum to the acetabular bone. We aim to describe a technique for labral repair with a knotless tensionable suture anchor. This technique uses a looped suture configuration, allowing selective tensioning of the repair to maintain the anatomic suction seal of the hip. The use of this technique is easily reproducible and reduces the surgical time compared with previous techniques.

Clinical and radiographical results of labral reconstruction

Treatment of femoroacetabular impingement (FAI) includes correction of underlying bony deformities. Labrum preservation is recommended whenever possible. In hips, where the labrum is missing or damaged beyond preservation, labral reconstruction is an option to restore labral seal. Between 2008 and 2011, 84 hips underwent treatment for FAI by means of a surgical hip dislocation. In 13 of these hips (11 patients), the severely damaged or missing labrum was reconstructed with ligamentum capitis femoris. Pre- and postoperative radiographic and clinical data were analysed with a mean follow-up of 38 months (range: 19–65 months). Clinical outcome was determined with Oxford hip score (OHS) and overall satisfaction, rest and load pain with a visual analogue scale (VAS; 0–100). Clinical outcome was compared with a control group where labral refixation was performed. Mean OHS improved significantly (P ≤ 0.001) from 29 (SD 8) to 44 (SD 4). Overall satisfaction with the hip increased significantly (P = 0.002) from 44 (SD 35) to 87 (SD 15). Mean VAS for rest pain decreased significantly (P = 0.0004) from 45 (SD 35) to 5 (SD 7) as well as for load pain (P = 0.0007) from 59 (SD 26) to 16 (SD 19). There were no significant differences between the two groups. Reconstruction of the acetabular labrum with ligamentum capitis femoris yields good clinical results. Technical superiority of open labral reconstruction may explain the unexpected, excellent outcome.