Anterior Capsule Reconstruction of the Native Hip: A Technique Guide

Hip Capsular Reconstruction With Indirect Head of the Rectus Femoris Tendon

Hip capsulotomy is performed during arthroscopic hip procedures to achieve adequate visualization of the joint and instrument access. The hip capsule, and in particular the iliofemoral ligament, is an important stabilizer of the hip joint, and patients who undergo capsulotomy without subsequent repair may experience hip pain and instability, with increased risk of requiring revision hip arthroscopy. Therefore, restoring watertight closure of the capsule is necessary to restore native biomechanics and achieve desired postoperative outcomes. Although primary repair or plication suffice in most cases, capsule reconstruction may instead be necessary when there is insufficient tissue, often due to capsular insufficiency following index surgery. The purpose of this Technical Note is to describe the authors' current technique for arthroscopic hip capsular reconstruction using the indirect head of the rectus femoris tendon in the setting of capsular iatrogenic hip instability, as well as its advantages and disadvantages and technical pearls and pitfalls.

Magnetic Resonance Arthrogram Improves Visualization of Hip Capsular Defects in Patients Undergoing Previous Hip Arthroscopy

Purpose

To compare magnetic resonance imaging (MRI) with magnetic resonance arthrogram (MRA) in the identification of hip capsular defects in patients who previously underwent hip arthroscopy.

Methods

Patients who underwent revision hip arthroscopy for capsular insufficiency by a single surgeon between March 2014 and December 2019 were identified by Current Procedural Terminology code. Patients with arthroscopically confirmed capsular defects treated surgically who underwent both MRI and MRA between their primary and revision surgeries were identified. Imaging studies were blinded, randomized, and distributed to two fellowship-trained musculoskeletal radiologists. Radiologists evaluated 14 components of different anatomic structures, including the presence of capsular defect and defect grading, over 2 months, with a 2-week washout period between 4 sets of reads to obtain 2 complete reads from each radiologist. Data were analyzed in R version 4.0.2.

Results

Two hundred thirty patients underwent revision hip arthroscopy between March 2014 and December 2019. Twelve patients had both an MRI and an MRA of the operated hip performed between their primary and revision surgeries. Time between primary and revision hip arthroscopy was 2.0 ± 1.5 years (R: .3-6.3). Time between MRI and MRA was .6 ± .6 years (R: .0-1.6). Sensitivity for detecting hip capsular defects was significantly higher for MRA than for MRI (87.5%, 95% CI: [68,96] vs 50%, 95% CI: [31,69], respectively; P = .008).

Conclusions

This retrospective review demonstrates that MRA has higher sensitivity than MRI in detecting surgically confirmed capsular defects. MRA may be more helpful in identifying capsular defects in patients presenting with hip instability symptoms who have had a previous hip arthroscopy.

Level of Evidence

Level IV, diagnostic case series.

Hip Capsular Deficiency-A Cause of Post-Surgical Instability in the Revision Setting Following Hip Arthroscopy for Femoroacetabular Impingement

PURPOSE OF REVIEW

To characterize current concepts in capsular repair and hip instability, and examine findings from biomechanical and clinical studies on hip capsular management strategies as they pertain to hip stability, patient outcomes, and hip arthroscopy failure. Further, we discuss the clinical evaluation and treatment of capsular deficiency.

RECENT FINDINGS

There remains debate regarding the optimal capsular management strategies in hip arthroscopy, particularly concerning the necessity of routine capsular repair. A variety of capsulotomy techniques exist and may be used to access the hip joint. Additionally, a wide variety of techniques are employed to repair the hip capsule. Biomechanical evidence supports capsular closure restores hip joint stability to that of the intact, native state. Several clinical studies in both primary and revision hip arthroscopy settings have demonstrated improved pain and functional outcomes in patients who underwent capsular repair or capsular reconstruction. Studies have shown capsular repair may be especially important in patients with ligamentous laxity and hip dysplasia, and in competitive athletes. Post-surgical hip instability secondary to capsular insufficiency is increasingly recognized as a cause of hip arthroscopy failure. Capsular closure restores native biomechanical stability to the hip joint, and several clinical studies report improved pain and functional outcomes following capsular repair or capsular reconstruction in both the primary and revision hip arthroscopy settings. There remains much to learn regarding capsular hip instability as it relates to optimal capsular management surgical technique, intra-operative capsular management decision-making, clinical diagnosis, and related advanced imaging findings.

Three-Dimensional Magnetic Resonance Arthrography of Post-Arthroscopy Hip Instability Demonstrates Increased Effective Intracapsular Volume and Anterosuperior Capsular Changes

Purpose

To quantify the magnetic resonance arthrography (MRA) capsular morphologic findings associated with postarthroscopy hip instability.

Methods

Among patients with clinically significant iatrogenic hip instability at a single center, patients with preindex and postindex surgery MRAs were identified. These MRAs were compared regarding effective intracapsular volume calculated by semi-automated 3-dimensional pixel intensity region segmentation, 2-dimensional anterior proximal intracapsular area in the femoral neck axial plane reconstruction, maximal anterior fluid pocket depth, capsule retraction distance, and capsular instability grade. Morphological measurements were conducted using Horos image processing software. Paired t-test, paired Wilcoxon signed rank test, and the McNemar test were used for identifying statistical significance.

Results

In 42 patients, mean effective intracapsular volume was significantly greater in the postindex surgery MRAs (19.44 cm³ vs 17.26 cm³; P = .006). Proximal anterosuperior (12-3 o'clock) intracapsular area was also significantly greater after index surgery (2.84 cm² vs 1.43 cm²; P < .001. Proximal anteroinferior (3-6 o'clock) intracapsular area (1.34 cm² vs 0.97 cm²; P = .002), capsule deficiency grade (P < .001), anterior capsule retraction distance (4.83 mm vs 0.34 mm; P < .001), and maximum anterior fluid depth (8.33 mm vs 4.90 mm; P <.001) were also significantly increased after index surgery.

Conclusion

In comparison to the preoperative state, iatrogenic hip instability is associated with MRA findings that include increases in total effective intracapsular volume, proximal anterosuperior and anteroinferior intracapsular cross-sectional area, maximum proximal anterosuperior fluid depth, and capsule retraction distance.

Level of Evidence

Level IV, diagnostic case series.

Is there enough evidence to support hip capsular reconstruction? A systematic review of biomechanical studies

The aim of this study was to review and summarize the available biomechanical data on hip capsular reconstruction to guide clinical decision-making. A literature search was completed in December 2020 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify biomechanical cadaver studies on hip capsular reconstruction, hip capsulectomy or hip capsular defect. The investigated parameters included maximum distraction force, capsular state affecting range of motion (ROM), rotation and translation. Four studies met al. the inclusion–exclusion criteria. The median effective force for resisting maximum distraction for the reconstruction state, capsular defect state and the intact state was 171, 111 and 206 N, respectively. The defect capsule force was significantly lower (P = 0.00438) than the intact capsule force. The reconstruction state had a higher distraction force than that of the capsular defect, but due to heterogeneity, the overall effect size was not statistically significant. The capsular reconstruction state reduced excess motion and the degree of instability compared to the capsular defect state but restored the hip close to its native capsular state in the cadaveric model. When compared to capsulectomy/defect state, hip capsular reconstruction significantly improved the rotational stability and effective force at maximum distraction and minimized translation. However, no conclusions can be made regarding the most effective protocol due to the high heterogeneity between the four studies. Further biomechanical studies are needed to test various types of grafts under the same protocol.

Arthroscopic Hip Capsule Reconstruction for Anterior Hip Capsule Insufficiency in the Revision Setting

Iatrogenic hip instability is increasingly recognized as a cause of persistent pain and disability after hip arthroscopy. Many authors currently advocate capsular repair to reduce postoperative instability. However, anatomic deficiencies in the anterosuperior capsule can prevent a functional capsular repair, particularly in the revision setting. Capsular reconstruction has been shown to restore biomechanical stabilization in cadaveric models and improve short-term patient outcomes in patients with primary hip arthroscopy failure. Arthroscopic hip capsular reconstruction is technically challenging, largely owing to complex suture management and difficulties with graft placement and sizing. This article describes the capsular reconstruction technique, detailing the technical aspects of anterosuperior capsular defect identification; capsular preparation; suture management; and dermal allograft sizing, preparation, and positioning.

Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability

Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the static stabilizers of the hip joint. Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. The patient may present with a painful limp and recurrent subluxation sensation in the affected hip joint. Revision hip arthroscopy in this scenario is generally complicated, and it is not uncommon for all the soft-tissue stabilizers to be compromised. The labrum, ligamentum teres (LT), and capsule of the hip joint are often so damaged that reparation is not an option. Reconstruction of the torn LT is an established method to add secondary stability while addressing the labral pathology in the hip joint with microinstability. Concomitant reconstruction of all the static restraints has yet to be described addressing triple instability. This Technical Note presents a stepwise approach, including tips and pearls, for arthroscopic triple reconstruction of the labrum, LT, and capsule. We believe this method is a safe and reproducible way to effectively treat gross hip instability in young patients.

A Biomechanical Comparison of 2 Hip Capsular Reconstruction Techniques: Iliotibial Band Autograft Versus Achilles Tendon Allograft

BACKGROUND

Several techniques for hip capsular reconstruction have been described to address gross instability or microinstability due to capsular deficiency. However, objective biomechanical data to support their use are lacking.

PURPOSE

To compare the kinematic effect of 2 capsular reconstruction techniques (iliotibial band [ITB] graft and Achilles tendon graft). Kinematic effect encompassed rotational range of motion (ROM) as well as joint translation in the coronal, sagittal, and axial planes.

STUDY DESIGN

Controlled laboratory study.

METHODS

8 paired, fresh-frozen hemi-pelvises (16 hips) were tested on a custom-designed joint motion simulator in the intact state and after capsulectomy. Pairs were randomly allocated to either ITB or Achilles reconstruction and retested. Testing was performed at 0°, 45°, and 90° of flexion. Internal-external rotation (IR-ER) torques and abduction-adduction torques of 3 N·m were applied to the femur via a load cell at each position, and rotational ROM and joint translation in the coronal, sagittal, and axial planes were recorded.

RESULTS

At 45° and 90°, there was a significant effect of the condition of the hip on the total IR-ER (P = .004, effect size [ES] = 0.305; and P < .001, ES = 0.497; respectively). At 45°, mean ± SD total rotation was significantly greater for the capsulectomy (59.7°± 15.9°) state compared with intact (53.3°± 13.2°; P = .007). At 90°, reconstruction significantly decreased total rotation to 49.0°± 18.9° compared with a mean total rotation of 52.8°± 18.7° after capsulectomy (P = .02). No difference was seen in the total abduction-adduction of the hip between conditions. Comparisons of the 2 different reconstruction techniques showed no significant differences in total IR-ER or abduction-adduction ROM or joint translation in the coronal, sagittal, or axial planes. For translation, at both 0° and 45° there was a statistically significant effect of the condition on the medial-lateral translation (P = .033; ES = 0.204). Reconstruction, independent of technique, was successful in significantly decreasing (P = .030; P = .014) the mean medial-lateral translation at 0° and 45° of hip flexion from 5.2 ± 3.8 mm and 5.6 ± 4.0 mm to 2.8 ± 1.9 mm and 3.9 ± 3.2 mm, respectively.

CONCLUSION

The integrity of the native hip capsule played a significant role in rotational stability, where capsulectomy significantly increased rotational ROM. Both ITB and Achilles reconstruction techniques restored normal rotational ROM of the hip at 90° of flexion as well as coronal plane stability at 0° and 45° of hip flexion. No differences were seen between ITB and Achilles reconstruction techniques.

CLINICAL RELEVANCE

Both capsular reconstruction techniques provide comparable joint kinematics, restoring rotation and translation to normal values with the exception of rotational ROM at 45°, which remained significantly greater than the intact state. The most significant results were the rotational stability at 90° of hip flexion and coronal plane stability at 0° and 45° of hip flexion, which were significantly improved compared with the capsulectomy state.