Comparison of Coracoid Graft Position and Fixation in the Open Versus Arthroscopic Latarjet Techniques: A Cadaveric Study

Biomechanical Evaluation of the 2 Different Levels of Coracoid Graft Positions in the Latarjet Procedure for Anterior Shoulder Instability

Background

In the Latarjet procedure, the ideal placement of the coracoid graft in the medial-lateral position is flush with the anterior glenoid rim. However, the ideal position of the graft in the superior-inferior position (sagittal plane) for restoring glenohumeral joint stability is still controversial.

Purpose

To compare coracoid graft clockface positions between the traditional 3 to 5 o'clock and a more inferior (for the right shoulder) 4 to 6 o'clock with regard to glenohumeral joint stability in the Latarjet procedure.

Study Design

Controlled laboratory study.

Methods

A total of 10 fresh-frozen cadaveric shoulders were tested in a dynamic, custom-built robotic shoulder model. Each shoulder was loaded with a 50-N compressive load while an 80-N force was applied in the anteroinferior axes at 90° of abduction and 60° of shoulder external rotation. Four conditions were tested: (1) intact, (2) 6-mm glenoid bone loss (GBL), (3) Latarjet procedure fixed at 3- to 5-o'clock position, and (4) Latarjet procedure fixed at 4- to 6-o'clock position. The stability ratio (SR) and degree of lateral humeral displacement (LHD) were recorded. A 1-factor random-intercepts linear mixed-effects model and Tukey method were used for statistical analysis.

Results

Compared with the intact state (1.77 ± 0.11), the SR was significantly lower after creating a 6-mm GBL (1.14 ± 0.61, P = .009), with no significant difference in SR after Latarjet 3 to 5 o'clock (1.51 ± 0.70, P = .51) or 4 to 6 o'clock (1.55 ± 0.68, P = .52). Compared with the intact state (6.48 ± 2.24 mm), LHD decreased significantly after GBL (3.16 ± 1.56 mm, P < .001) and Latarjet 4 to 6 o'clock (5.48 ± 3.39 mm, P < .001). Displacement decreased significantly after Latarjet 3 to 5 o'clock (4.78 ± 2.50 mm, P = .04) compared with the intact state but not after Latarjet 4 to 6 o'clock (P = .71).

Conclusion

The Latarjet procedure in both coracoid graft positions (3-5 and 4-6 o'clock) restored the SR to the values measured in the intact state. A more inferior graft position (fixed at 4-6 o'clock) may improve shoulder biomechanics, but additional work is needed to establish clinical relevance.

Clinical Relevance

An inferior coracoid graft fixation, the 4- to 6-o'clock position, may benefit in restoring normal shoulder biomechanics after the Latarjet procedure.

How to Fashion the Bone Block for Reconstruction of the Glenoid in Anterior and Posterior Instability

BACKGROUND

Glenoid restoration techniques to address glenohumeral instability-induced anterior and posterior glenoid bone loss (AGBL and PGBL) often require reconstruction, but best-fit bone block (BFBB) modeling has not been developed.

PURPOSE

To provide glenoid bony reconstruction models for anterior and posterior instability of the shoulder using a bone loss instability cohort with high-fidelity 3-dimensional (3D) imaging.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We reviewed consecutive patients indicated for operative stabilization who had posterior glenohumeral instability and suspected GBL who underwent 2-dimensional (2D) computed tomography (CT). Patients were matched by sex, laterality, and age to patients who underwent operative stabilization of anterior glenohumeral instability. Mimics software was used to convert all 2D CT scans into 3D models of the scapula. A BFBB model was designed to digitally reconstruct GBL and was used to predict the amount, anatomic configuration, and fixation configuration of bony reconstruction required in AGBL and PGBL.

RESULTS

The study included 30 patients with posterior instability and 30 patients with anterior instability; the participants' mean ± SD age was 28.8 ± 8.15 years (range, 16.0-51.0 years). Mean surface area of AGBL was 24.9% ± 7.7% (range, 14.7%-39.1%). Mean BFBB dimensions to reconstruct the anterior glenoid were determined to be a superior-inferior length of 23.9 ± 4.2 mm, anterior-posterior width of 6.4 ± 2.4 mm, and height of 1 cm. Mean angle of AGBL bone block interface relative to glenoid to reconstruct the native concavity was 79.4°± 5.9°. For PGBL, the mean surface area was 9.2% ± 5.6% (range, 3.0%-26.3%). Mean BFBB dimensions to reconstruct the posterior glenoid were a superior-inferior length of 21.9 ± 3.4 mm, width of 4.5 ± 2.3 mm, and height of 1 cm. The mean angle of PGBL bone block interface relative to the glenoid to reconstruct the native concavity was 38.6°± 14.3°. Orientation relative to the vertical glenoid axis was 77.2°± 13.8° in anterior reconstructions versus 105.9°± 10.9° in posterior reconstructions.

CONCLUSION

Patients with anterior instability required a more rectangular BFBB with a bone block-glenoid interface angle of 79°, whereas patients with posterior instability required a more trapezoidal, obtusely oriented BFBB with a bone block-glenoid interface angle of 39°. BFBBs for either AGBL or PGBL can be effectively designed, and their size and/or shape can be predicted based on approximate percentage of GBL.

Anterior Shoulder Instability Part II-Latarjet, Remplissage, and Glenoid Bone-Grafting-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on the Latarjet procedure, remplissage, and glenoid-bone grafting for anterior shoulder instability.

METHODS

A consensus process on the treatment utilizing a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The technical approaches identified in the statements on the Latarjet procedure and glenoid bone-graft were that a subscapularis split approach should be utilized, and that it is unclear whether a capsular repair is routinely required. Furthermore, despite similar indications, glenoid bone-grafting may be preferred over the Latarjet in patients with bone-loss greater than can be treated with a coracoid graft, and in cases of surgeon preference, failed prior Latarjet or glenoid bone-grafting procedure, and epilepsy. In contrast, the primary indications for a remplissage procedure was either an off-track or engaging Hill-Sachs lesion without severe glenoid bone loss. Additionally, in contrast to the bone-block procedure, complications following remplissage are rare, and loss of shoulder external rotation can be minimized by performing the tenodesis via the safe-zone and not over medializing the fixation.

CONCLUSION

Overall, 89% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the prognostic factors that are important to consider in those undergoing a glenoid bone-grafting procedure including age, activity level, Hill-Sachs Lesion, extent of glenoid bone-loss, hyperlaxity, prior surgeries, and arthritic changes. Furthermore, there was unanimous agreement that it is unclear whether a capsular repair is routinely required with a glenoid bone graft, but it may be beneficial in some cases. There was no unanimous agreement on any aspect related to the Latarjet procedure or Remplissage.

LEVEL OF EVIDENCE

Level V, expert opinion.

Modified Arthroscopic Latarjet Procedure: Button Fixation Without Splitting of the Subscapularis

The Latarjet procedure is used for the treatment of anterior glenohumeral instability in the presence of bone loss. One decade after a fully arthroscopic Latarjet procedure was described, this technique has been modified to reduce the risk of complications and improve the fixation method. We aimed to simplify the components of this surgical procedure.

Short-Term Bone Fusion With Arthroscopic Double-Button Latarjet Versus Open-Screw Latarjet

BACKGROUND

Recently, arthroscopic double-button Latarjet (AL) has provided an alternative to conventional open Latarjet (OL) in the treatment of anterior shoulder instability with glenoid bone loss. Therefore, theoretically, the faster fusion is obtained, the sooner return to sports under safe conditions can occur. The emerging flexible fixation of the bone block has clearly offered a new approach to achieve bone fusion. However, the period required to achieve this goal remains controversial.

PURPOSE/HYPOTHESIS

The purpose was to compare computed tomography (CT) scan results of AL and OL in the early postoperative period. It was hypothesized that the bone block fusion with AL would require a longer time than that with OL.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

In a retrospective 1-year study, the authors compared 17 primary double-button AL to 22 primary 2-screw OL procedures indicated for anterior shoulder instability in patients with an Index Severity Instability Score >3 points. These patients were reviewed with a CT scan at 1 day, 3 months, and 6 months postoperatively. The characteristics for the 2 groups were comparable. CT scans aimed to analyze graft position, bone contact area with the scapula, and fusion at 3 and 6 months. Clinical assessment was based on the Walch-Duplay and Rowe scores.

RESULTS

The mean preoperative Index Severity Instability Score was 5.3 ± 1.9 points, with a mean anterior glenoid bone loss of 9.1% ± 4.6%. At 3 months, the rates of fusion were 41% and 100% for the AL and OL groups, respectively (P < .001). This rate increased to 70% in the AL group at 6 months (P = .006). In the axial and sagittal planes, there was no difference in graft position between the AL group and the OL group. The bone block was longer and there was a more extensive bone contact area in the OL group (AL, 131 mm² vs OL, 223 mm²; P < .001). At 6 months of follow-up, no significant difference in clinical scores was noted between the groups: Walch-Duplay score, 93.0 ± 10.9 points versus 91.8 ± 12.5 points (P = .867); and Rowe score, 99.0 ± 2.2 points versus 95.0 ± 8.4 points (P = .307) for the AL and OL groups, respectively.

CONCLUSION

AL required more time to achieve bone block fusion than OL. This finding should be taken into account when considering this procedure for patients in a hurry to return to sports involving the shoulder.

Latarjet Cerclage: The All-Arthroscopic Metal-Free Fixation

The Bristow-Latarjet procedure has been one of the most recognized procedures for the treatment of recurrent shoulder dislocation with anterior glenoid bone loss, revision surgery after failed Bankart repair, contact and collision sport injuries, and patients with a high risk of recurrence. Open and arthroscopic approaches have recently shown similar outcomes by several authors. However, complications related to metal implants, despite being low, are still a matter of concern. We describe an all-arthroscopic Latarjet technique with a metal-free fixation method using 2 ultra-high-strength sutures, creating a cerclage construct through 2.4mm glenoid and coracoid tunnels with a final capsulolabral complex reconstruction.