Arthroscopic Inverting Repair Technique for Inside-Out Hip Labral Tears

Abstract

The acetabular labrum is a fibrocartilaginous structure that deepens the acetabular socket and helps maintain a suction seal. In patients with hip dysplasia, a distinct labral tear pattern called an inside-out labral tear is often seen. This tear pattern is particularly challenging to correct via conventional techniques since the labrum can potentially remain everted and insufficiently restore the native hip labral suction seal after repair. An inverted hip labral repair technique is performed for this pathology at our institution and focuses on achieving optimal labral orientation to enhance the suction seal and joint stability, particularly in dysplastic hips. This Technical Note aims to describe the key surgical principles and clinical considerations of inverted hip labral repair.

The acetabular labrum is a fibrocartilaginous structure that plays a crucial role in hip joint stability and function by deepening the acetabular socket and maintaining a suction seal. Hip labral tears can often lead to significant pain, dysfunction, and activity limitations if left untreated. Arthroscopic acetabular labrum repair is a minimally invasive technique to restore its anatomic integrity and biomechanical function.¹

In patients with hip dysplasia, a particular labral tear pattern called an inside-out labral tear is often seen.² This tear is distinct from labral pathology seen as a result of femoroacetabular impingement (FAI). In cam-based FAI, the femoral cam impinges upon the labrum during hip flexion, causing cartilage delamination and labral tearing.² In dysplastic hips, the superiorly directed force of the femoral head on the acetabular rim due to microsubluxation causes an injury pattern that originates as a central tear in the articular cartilage and labrum, propagating outward as a contiguous chondrolabral sleeve (Fig 1, Fig 2, Fig 1, Fig 2).³ This tear pattern is especially challenging to correct via conventional techniques since the labrum can potentially remain persistently everted and insufficiently restore the native hip labral suction seal.

Fig 1.

Anteroposterior pelvis radiograph of the patient with hip dysplasia. (LCEA, lateral center-edge angle.)

Fig 2.

Arthroscopic image of a left hip from the anterolateral portal with the yellow arrow pointing to the patient’s inside-out labral tear pattern.

Literature on arthroscopic hip labral repair highlights the importance of proper technique and restoration of labral function for successful long-term outcomes, which emphasizes the need for techniques that maximize inversion and labral contact with the femoral head.⁴ The inverted hip labral repair technique focuses on achieving optimal labral orientation to enhance the suction seal and joint stability, particularly in dysplastic hips.^5,6 For inside-out labral tear patterns, this inverted labral repair technique may be more appropriate to restore labral function than traditional techniques. This Technical Note and associated video (Video 1) aims to describe the key surgical principles and clinical considerations of inverted hip labral repair.

Surgical Technique

The patient is positioned supine on a traction table with a well-padded perineal post and feet placed into traction boots (Fig 3). After induction of anesthesia, the operative extremity is prepped and draped in the usual sterile fashion. After traction is applied, an anterolateral (AL) portal is established using a 17-gauge spinal needle under fluoroscopic localization (Fig 4). Access to the joint is confirmed using an air arthrogram. Arthroscopic visualization through the AL portal is used to establish a mid-anterior portal (MAP), and a Clear-Trac cannula is placed (Smith & Nephew). Diagnostic arthroscopy is then completed, viewing through the AL portal, and the inside-out labral tear is identified and characterized (Fig 5). The femoroacetabular articulation is assessed, which may show an inadequate labral suction seal (Fig 6). Acetabular rim preparation is carried out using a combination of an arthroscopic shaver and radiofrequency device, and temporary retraction stitches are placed in the capsule with a Slingshot (Stryker) suture-passing device as needed for adequate visualization. A distal anterolateral accessory (DALA) portal is then established under arthroscopic visualization (Fig 7). Of note, it is beneficial to place the DALA portal as distal as possible in order to achieve the proper angle and drill trajectory for anchor placement along the acetabular rim.

Fig 3.

Patient positioning on a traction table with the operative extremity secured into a well-padded boot and utilization of a padded perineal post.

Fig 4.

Fluoroscopic image of a left hip under traction showing needle localization and performance of an air arthrogram.

Fig 5.

Arthroscopic image of a left hip from the anterolateral portal during diagnostic arthroscopy showing labral tearing and chondrolabral delamination.

Fig 6.

Arthroscopic view of a left hip from the anterolateral portal of the femoroacetabular articulation after traction is released, showing a poor suction seal in the region labeled by the yellow arrow.

Fig 7.

Arthroscopic image of a left hip from the anterolateral portal establishing the distal anterolateral accessory portal under arthroscopic visualization. A suspension suture is visualized in the medial capsule leaflet.

The inside-out labral repair is performed by first inserting a curved drill guide through the DALA portal over a nitinol guidewire, positioned on the undersurface of the acetabular rim, between the labrum and the acetabular cartilage, starting at the medial-most aspect of the labral tear (Fig 8). Fluoroscopy can be used to confirm drill guide positioning (Fig 9) and proper trajectory within the osseous confines of the acetabular rim. The drill is advanced slowly, ensuring no damage to the articular surface or extraosseous penetration occurs. A 1.4-mm NanoTack (Stryker) PEEK (polyether ether ketone) knot-tying hard-body suture anchor is seated and deployed through the guide (Fig 10). A NanoPass (Stryker) suture-passing device is passed through the MAP and under the labrum in an outside-in fashion (Fig 11). The drill guide in the DALA portal is utilized to facilitate suture retrieval with the NanoPass (Stryker) (Fig 12). Once the suture is grasped, it is passed around the labrum so that the free end of the suture then lies on the outer surface of the labrum adjacent to the acetabular rim. An arthroscopic grasper is placed through the MAP cannula to avoid any soft tissue bridges and is used to retrieve and pass both suture limbs outside the joint (Fig 13).

Fig 8.

Arthroscopic image of a left hip from the anterolateral portal. The inside-out labral repair is performed by first inserting a curved drill guide through the distal anterolateral accessory portal over a nitinol guidewire, positioned between the labrum and articular cartilage.

Fig 9.

Fluoroscopic image of a left hip confirming adequate drilling trajectory on the acetabular rim prior to anchor placement.

Fig 10.

Arthroscopic image of a left hip from the anterolateral portal showing placement of the anchor with suture limbs on the articular side of the labrum.

Fig 11.

Arthroscopic image of a left hip from the anterolateral portal showing a suture-passing device passed through the mid-anterior portal and under the labrum in an outside-in fashion.

Fig 12.

Arthroscopic image of a left hip from the anterolateral portal depicting the use of the curved drill guide to aid in suture retrieval. The guide is left in the distal anterolateral accessory portal so that the suture limbs are within the drill guide and can be easily controlled. This minimizes movement required by the suture-passing device, which is underneath the labrum.

Fig 13.

Arthroscopic view of a left hip from the anterolateral portal showing the suture location prior to tying.

Labral inversion is then begun by shortening the suture limb on the acetabular side of the labrum, which will function as the knot post. Knots are then tied using an arthroscopic knot pusher through the MAP with appropriate tension (Fig 14). Additional anchors are placed as needed every 5 to 10 mm in a similar fashion, working medial to lateral. Once the inverted labral repair is completed, traction is released, and the suction seal is assessed (Fig 15). Our stepwise approach is outlined in Table 1. After completion of the labral repair and any additional work in the central compartment, concomitant procedures in the peripheral compartment are then completed as necessary.

Fig 14.

Arthroscopic images of a left hip from the anterolateral portal showing sequential photos (ordered numerically) of knot tying and labral inversion.

Fig 15.

Arthroscopic images of a left hip from the anterolateral portal after completion of the labral repair and releasing traction. Preoperative evaluation shows that poor suction seal (A) has been improved by our inversion labral repair (B).

Table 1.

Stepwise Approach to Inverted Hip Labral Repair

1.Perform diagnostic arthroscopy, characterizing the labral tear and assessing the condition of articular cartilage 2.Let down traction briefly to assess the femoroacetabular articulation and suction seal 3.Establish the DALA portal under arthroscopic visualization 4.Insert drill guide and position beneath the undersurface of the labrum on the acetabular rim, between the labrum and articular cartilage 5.Drill under arthroscopic visualization and fluoroscopy as needed 6.Use the suture-passing device to retrieve 1 limb of the suture under the labrum in an inside-out fashion so that 1 limb of suture is on either side of the labrum 7.Shorten the suture limb on the acetabular rim side of the labrum and use as the post for knot tying to produce labral inversion 8.Place additional anchors as outlined in steps 9 to 12 every 5 to 10 mm along the labral tear 9.Release traction and reassess femoroacetabular articulation

DALA, distal anterolateral accessory.

Postoperative Protocol

Patients are restricted to 25% weightbearing for 4 weeks postoperatively, with range of motion limited to 90° of hip flexion, 10° of extension, internal/external rotation limited to 20°, and abduction to 30°. Progressive weightbearing based on patient symptoms is initiated during physical therapy in postoperative week 4. After 6 weeks, the goal is to return to community ambulation with full range of motion. Patients are allowed to return to jogging at 12 weeks and cleared for full return to sport activities at week 16 so long as they remain asymptomatic.

Discussion

The inverted labral repair technique addresses the challenge of achieving optimal labral orientation for the inside-out labral tear pattern frequently seen in hip dysplasia. An inside-out hip labral tear is assigned to tears that begin centrally in the articular cartilage due to abnormal shear forces, which cause a chondrolabral sleeve to extend peripherally.^1,7 In a retrospective review by Kraeutler et al.,¹ inside-out tear patterns were found more commonly in dysplastic hips (lateral center-edge angle ≤20°). Inversion of the labrum during repair maximizes the contact area between the labrum and the femoral head, enhancing the suction seal and restoring joint stability. This approach was previously described by Mei-Dan et al.⁷ and can be particularly beneficial in cases where labral eversion is a concern, such as in inside-out tear patterns in patients with underlying hip dysplasia. Our technique builds upon this and shows a straightforward, reproducible method for obtaining labral inversion, particularly for more central and lateral labral tears. Use of a curved drill guide through a well-positioned DALA portal allows for anchors to be safely inserted and deployed on the acetabular rim, and using the drill guide to assist in suture retrieval is a key to success of this technique. Precise anchor placement and suture tension are critical to achieving a successful inverted repair. Other pearls and pitfalls are listed in Table 2.

Table 2.

Advantages and Disadvantages of the Inverted Labral Repair

Advantages	Disadvantages
•Anatomic repair with improved suction seal by increasing contact between the labrum and femoral head	•Anchor placement can be challenging, placing articular cartilage at risk of damage
•Allows for placement of far medial and/or lateral anchors to fully address the extent of the labral tear •Technique allows for facile suture passage and management, increasing surgical efficiency	•Knot stacks may increase theoretical risk of labral adhesion formation •May require increased use of fluoroscopy to avoid extraosseous penetration when drilling

This technique is advantageous as it improves the ability to restore the hip joint suction seal with the use of several reproducible tips and checkpoints to ensure the challenges of performing hip arthroscopic labral repair can be met safely and efficiently. Disadvantages of this technique include the need for a third portal and potentially increased fluoroscopy use to verify the trajectory when placing the anchors via an inside-out drilling fashion. Additional advantages and disadvantages are outlined in detail in Table 3. Labral repair and restoration of native function in the dysplastic hip are a necessary part of hip preservation. However, a thorough evaluation for other hip pathology (e.g., FAI, arthritis) must be performed, as their presence may alter the management of labral pathology.⁸ These patients should also be counseled that, depending on their specific pathology and severity of disease, additional procedures such as pincer/cam decompression or periacetabular osteotomy may be indicated in cases of significant undercoverage in order to achieve optimal outcomes.

Table 3.

Pearls and Pitfalls of Inverted Labral Repair

Pearls	Pitfalls
•Appropriately positioned DALA portal is key for proper positioning of the curved drill guide on the acetabular rim	•Improper placement of the DALA portal may increase difficulty of anchor placement
•Use of the drill guide to aid in suture retrieval by pushing toward suture-passing device	•Aberrant trajectory of the drill guide can lead to intra-articular anchor placement and cartilage damage
•The curved drill guide decreases risk of intra-articular penetration and iatrogenic cartilage damage	•Attempting to retrieve the suture limbs through the cannula with the suture-passing device and not an arthroscopic grasper may fray or cut the sutures

DALA, distal anterolateral accessory.

Disclosures

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: E.G. is a board member of the Pediatric Orthopaedic Society of North America. R.J.S. is a board member of the Muller Foundation and the Hip Society. A.J.K. is a paid consultant for Arthrex, is a member of the editorial or governing board for the American Journal of Sports Medicine and Springer, receives research support from Aesculap/B. Braun, receives IP royalties from Arthrex, and is a board or committee member of the Arthroscopy Association of North America and the International Cartilage Repair Society. M.H. is a paid consultant for DJO-Enovis, Moximed, Stryker, and Vericel; is a member of the editorial or governing board for the Journal of Cartilage and Joint Preservation; and receives publishing royalties and financial or material support from Elsevier. All other authors (B.C.C., A.C.H., J.I., L.K.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplementary Data

Video 1

Arthroscopic technique for inverting labral repair in the setting of inside-out labral tears, as demonstrated in a left hip. Viewing performed from the anterolateral (AL) portal with instrumentation including retrieval and tying from the mid-anterior portal (MAP). Drilling performed from the distal anterolateral accessory portal (DALA). A deficient suction seal is restored upon relocation of the hip.