Accuracy of Latarjet graft and screw position after using novel drill guide

Use of 3D-Printed Patient-Specific Guide for Latarjet Procedure in Patients With Anterior Shoulder Instability: Technical Note

Anterior shoulder instability can lead to anterior glenoid bone loss associated with humeral posterior deformity (bipolar bone loss). Latarjet procedure is a commonly used surgical option in such cases. However, the procedure is associated with complications in up 15% of the cases often associated with inadequate positioning of coracoid bone graft and screws. Considering that acknowledgment of patient anatomy and use of surgical planning intraoperatively can reduce such complications, we describe the use of 3D printing tools to obtain a 3D Patient-Specific Surgical Guide to aid in the Latarjet procedure. Such tools present advantages and limitations compared to other tools available, which are also discussed in this article.

Arthroscopically-assisted Latarjet: an easy and reproducible technique for improving the accuracy of graft and screw placement

BACKGROUND

The effectiveness of the Latarjet largely depends on accurate graft placement, as well as on proper position and direction of the screws. We present our technique for an arthroscopically-assisted Latarjet comparing radiological results with the open technique.

METHODS

We retrospectively reviewed the postoperative computed tomography scans of 38 patients who underwent a Latarjet procedure. For 16 patients, the procedure was performed with the open technique and, for 22 patients, it was performed using an arthroscopically-assisted technique. An independent radiologist evaluated graft and hardware position, as well as graft integration or resorption. Postoperative complications were also documented.

RESULTS

The graft was correctly placed in only 18.8% of cases in the open group and 72.7% of cases in the arthroscopically-assisted group. There were no postoperative complications in the arthroscopically-assisted group, whereas one patient had a recurrence and two required hardware removal in the open group.

CONCLUSIONS

The Latarjet procedure is a challenging procedure for which a key point is the correct placement of the coracoid graft onto the glenoid neck and correct position of the screws. The present study substantiates a clear benefit for the use of a guide with an arthroscopically-assisted technique in terms of graft and hardware placement. At short-term follow-up, there appears to be a benefit for graft integration and avoidance of resorption.

Anthropometric and Radiologic Measurements of Coracoid Dimensions and Clinical Implications in an Indian Population

Background:

Recurrent shoulder dislocation and anterior instability are most commonly attributed to pathology of the capsulolabral complex with the presence of bony loss at the humeral and glenoid surfaces. Unassessed bone loss has been a cause of failure of primary soft tissue procedures or recurrence of symptoms, despite adequate address of soft tissue pathology.

Purpose:

To study the anthropometric and radiologic dimensions of the coracoid in relation to glenoid bone loss, its adequacy in filling glenoid defects in an Indian population, and whether the choice of surgical technique (congruent arc vs classical) and graft positioning alters the surgical results. This study also intended to establish whether computed tomography measurements correlate with actual anthropometric measurements.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 64 participants with 108 healthy shoulders were included in this study. Additionally, 100 skeletally mature bone specimens of the scapula were measured to assess glenoid diameter as well as coracoid width and length in 2 perpendicular planes with a humeral subtraction 3-dimensional en face glenoid view.

Results:

Specimen and participant measurements proved that the congruent arc technique was able to fill up to 50% more glenoid bone loss than the classical technique in an Indian population (mean ± SD, 13.45 ± 6.97 vs 7.96 ± 4.89 mm, respectively), with computed tomography being the best and most accurate modality to study it. The mean difference in the bone block length restoration of the glenoid bony arc was 5.41 ± 2.08 mm. Radii of curvature were congruent in populations of the Indian subcontinent.

Conclusion:

The congruent arc technique can be performed in an Indian population but with caution and careful presurgical assessment of bone loss. However, adequate coracoid dimension to accommodate the implant for fixation without failure must be ensured, as anthropometry suggests the existence of a subset of the population in whom the graft may have compromised width for accommodating standard implants for fixation.

Can a Drill Guide Improve the Coracoid Graft Placement During the Latarjet Procedure? A Prospective Comparative Study With the Freehand Technique

Background

One of the factors that can affect the success of the Latarjet procedure is accurate coracoid graft (CG) placement.

Hypothesis

The use of a guide can improve placement of the CG and screw positioning in the sagittal and axial planes as compared with the classic open ("freehand") technique.

Study Design

Cohort study; Level of evidence, 2.

Methods

A total of 49 patients who underwent a Latarjet procedure for the treatment of recurrent anterior shoulder instability were prospectively included; the procedure was performed with the freehand technique in 22 patients (group 1) and with use of a parallel drill guide during screw placement in 27 patients (group 2). All patients underwent a postoperative computed tomography scan with the same established protocol. The scans were used to evaluate and compare the position of the CG in the sagittal and axial planes, the direction of the screws (α angle), and overall contact of the graft with the anterior surface of the glenoid after the 2 surgical techniques.

Results

The CG was placed >60% below the native glenoid equator in 23 patients (85.2%) in group 2, compared with 14 patients (63.6%) in group 1 (P = .004). In the axial plane, the position of the CG in group 2 patients was more accurate (85.2% and 88.9% flush) at the inferior and middle quartiles of the glenoid surface (P = .012 and .009), respectively. Moreover, with the freehand technique (group 1), the graft was in a more lateral position in the inferior and middle quartiles (P = .012 and .009, respectively). No differences were found between groups 1 and 2 regarding the mean α angle of the superior (9° ± 4.14° vs 11° ± 6.3°, P = .232) and inferior (9.5° ± 6° vs 10° ± 7.5°, P = .629) screws. However, the mean contact angle (angle between the posterior coracoid and the anterior glenoid surface) with the freehand technique (3.8° ± 6.8°) was better than that of the guide (8.55° ± 8°) (P = .05).

Conclusion

Compared with the classic freehand operative technique, the parallel drill guide can ensure more accurate placement of the CG in the axial and sagittal planes, although with inferior bone contact.