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Glenoid Rim Anatomy: Risk for Glenoid Vault Perforation During Labral Repair.

Levy YD, Williamson M, Flores-Hernandez C, D'Lima DD, Hoenecke HR - Orthop J Sports Med (2014)

Bottom Line: Optimal insertion angles and safe insertion ranges varied significantly with respect to the position on the glenoid face.The safe insertion range and optimal insertion angle were found to be wider at the anterior glenoid as compared with the posterior glenoid.A posterolateral insertion angle was safer than an anterior insertion angle at the 10:30 position.

View Article: PubMed Central - PubMed

Affiliation: Shiley Center for Orthopaedic Research and Education at Scripps Clinic, La Jolla, California, USA.

ABSTRACT

Background: Injuries to the glenoid labrum frequently require repair with anchors. Placing anchor devices arthroscopically can be challenging, and anchor malpositioning can complicate surgical outcomes.

Purpose: To determine the safe insertion range and optimal insertion angle of glenoid labral anchors at various positions on the glenoid rim and to establish surgical guidelines that minimize risk of anchor perforation.

Study design: Descriptive laboratory study.

Methods: Three-dimensional computed tomography scans of 30 normal cadaveric specimens were obtained. A virtual model of a generic labral anchor was inserted into the rim of the glenoid at the clockface positions represented by 12:00, 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, and 10:30. At each position, the safe insertion range was the maximal range measured, and the optimal insertion angle was identified as the angle between the bisector of the safe insertion range and the glenoid face.

Results: Progressing in the clockwise direction, beginning at the 12:00 position, the safe insertion ranges (mean ± SD ) were 55.9° ± 10.6°, 63.6° ± 17.6°, 47.7° ± 9.1°, 46.1° ± 8°, 73.9° ± 9.7°, 40.9° ± 6.5°, 40.4° ± 7.4°, and 39.9° ± 7.1°, respectively. The optimal insertion angles were 47.9° ± 7.6°, 53.1° ± 10.9°, 35.0° ± 4.4°, 42.4° ± 4.9°, 60.9° ± 8.4°, 36.6° ± 5.9°, 31.2° ± 4.9°, 34.8° ± 4.6°, respectively.

Conclusion: Optimal insertion angles and safe insertion ranges varied significantly with respect to the position on the glenoid face. The safe insertion range and optimal insertion angle were found to be wider at the anterior glenoid as compared with the posterior glenoid. A posterolateral insertion angle was safer than an anterior insertion angle at the 10:30 position.

Clinical relevance: Proper arthroscopic technique resulting in anchor insertion at the correct angle, depth, and location will prevent anchor-related glenohumeral complications such as glenoid perforation, cartilage damage, persistent pain, decreased range of motion, and failure of the reconstruction.

No MeSH data available.


Related in: MedlinePlus

Schematic illustration of a glenoid cross section, anchor placement, and angle measurements: (A) macroscopic appearance, (B) magnified image. The illustration demonstrates the safe insertion range (SIR) and the angle between 2 anchors (one bound by the glenoid articular surface and the other bound by the cortex of the glenoid neck), which represents the maximal measured range. The optimal insertion angle (OIA) is the angle between the bisector of the safe insertion range and the glenoid face. This angle represents the angle with the highest margin for error available for insertion without perforation.
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fig2-2325967114556257: Schematic illustration of a glenoid cross section, anchor placement, and angle measurements: (A) macroscopic appearance, (B) magnified image. The illustration demonstrates the safe insertion range (SIR) and the angle between 2 anchors (one bound by the glenoid articular surface and the other bound by the cortex of the glenoid neck), which represents the maximal measured range. The optimal insertion angle (OIA) is the angle between the bisector of the safe insertion range and the glenoid face. This angle represents the angle with the highest margin for error available for insertion without perforation.

Mentions: A virtual 3 mm–diameter, 15 mm–long model of a generic labral anchor was constructed using a commercially available 3D modeling program (RHINOCEROS 3D; McNeel). The glenoid was radially sectioned with planes that intersected at the glenoid center and that were normal to the glenoid face plane. There were planes that contained the following clockface positions: 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, 10:30, and 12:00. To simplify the analysis, the left-sided scapulae were converted, by mirroring, into right-sided scapulae; therefore, throughout this article when we discuss the clockface position, we refer to 9:00 as posterior and 3:00 as anterior. Figure 1A represents the cross sections in a right scapula. This approach is consistent with previous reports on the glenoid clockface position both in the orthopaedic and the radiologic literature.3,4,18,19 On each glenoid cross section, 2 anchors were superimposed having a common entry point on the rim of the glenoid: one bounded by the glenoid articular surface and the other bounded by the cortex of the glenoid neck. These 2 positions represented the extreme angles in which the anchor could be placed without perforating through the bone. We defined the “safe insertion range” as the angle between these 2 anchors. This angle represented the widest insertion margin for error available before perforating the glenoid vault. The “optimal insertion angle” was defined by the angle between the bisector of the safe insertion range and the glenoid face (Figure 2). We used the glenoid face as a convenient reference because it was usually well visualized during arthroscopic labral repair.


Glenoid Rim Anatomy: Risk for Glenoid Vault Perforation During Labral Repair.

Levy YD, Williamson M, Flores-Hernandez C, D'Lima DD, Hoenecke HR - Orthop J Sports Med (2014)

Schematic illustration of a glenoid cross section, anchor placement, and angle measurements: (A) macroscopic appearance, (B) magnified image. The illustration demonstrates the safe insertion range (SIR) and the angle between 2 anchors (one bound by the glenoid articular surface and the other bound by the cortex of the glenoid neck), which represents the maximal measured range. The optimal insertion angle (OIA) is the angle between the bisector of the safe insertion range and the glenoid face. This angle represents the angle with the highest margin for error available for insertion without perforation.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4555554&req=5

fig2-2325967114556257: Schematic illustration of a glenoid cross section, anchor placement, and angle measurements: (A) macroscopic appearance, (B) magnified image. The illustration demonstrates the safe insertion range (SIR) and the angle between 2 anchors (one bound by the glenoid articular surface and the other bound by the cortex of the glenoid neck), which represents the maximal measured range. The optimal insertion angle (OIA) is the angle between the bisector of the safe insertion range and the glenoid face. This angle represents the angle with the highest margin for error available for insertion without perforation.
Mentions: A virtual 3 mm–diameter, 15 mm–long model of a generic labral anchor was constructed using a commercially available 3D modeling program (RHINOCEROS 3D; McNeel). The glenoid was radially sectioned with planes that intersected at the glenoid center and that were normal to the glenoid face plane. There were planes that contained the following clockface positions: 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, 10:30, and 12:00. To simplify the analysis, the left-sided scapulae were converted, by mirroring, into right-sided scapulae; therefore, throughout this article when we discuss the clockface position, we refer to 9:00 as posterior and 3:00 as anterior. Figure 1A represents the cross sections in a right scapula. This approach is consistent with previous reports on the glenoid clockface position both in the orthopaedic and the radiologic literature.3,4,18,19 On each glenoid cross section, 2 anchors were superimposed having a common entry point on the rim of the glenoid: one bounded by the glenoid articular surface and the other bounded by the cortex of the glenoid neck. These 2 positions represented the extreme angles in which the anchor could be placed without perforating through the bone. We defined the “safe insertion range” as the angle between these 2 anchors. This angle represented the widest insertion margin for error available before perforating the glenoid vault. The “optimal insertion angle” was defined by the angle between the bisector of the safe insertion range and the glenoid face (Figure 2). We used the glenoid face as a convenient reference because it was usually well visualized during arthroscopic labral repair.

Bottom Line: Optimal insertion angles and safe insertion ranges varied significantly with respect to the position on the glenoid face.The safe insertion range and optimal insertion angle were found to be wider at the anterior glenoid as compared with the posterior glenoid.A posterolateral insertion angle was safer than an anterior insertion angle at the 10:30 position.

View Article: PubMed Central - PubMed

Affiliation: Shiley Center for Orthopaedic Research and Education at Scripps Clinic, La Jolla, California, USA.

ABSTRACT

Background: Injuries to the glenoid labrum frequently require repair with anchors. Placing anchor devices arthroscopically can be challenging, and anchor malpositioning can complicate surgical outcomes.

Purpose: To determine the safe insertion range and optimal insertion angle of glenoid labral anchors at various positions on the glenoid rim and to establish surgical guidelines that minimize risk of anchor perforation.

Study design: Descriptive laboratory study.

Methods: Three-dimensional computed tomography scans of 30 normal cadaveric specimens were obtained. A virtual model of a generic labral anchor was inserted into the rim of the glenoid at the clockface positions represented by 12:00, 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, and 10:30. At each position, the safe insertion range was the maximal range measured, and the optimal insertion angle was identified as the angle between the bisector of the safe insertion range and the glenoid face.

Results: Progressing in the clockwise direction, beginning at the 12:00 position, the safe insertion ranges (mean ± SD ) were 55.9° ± 10.6°, 63.6° ± 17.6°, 47.7° ± 9.1°, 46.1° ± 8°, 73.9° ± 9.7°, 40.9° ± 6.5°, 40.4° ± 7.4°, and 39.9° ± 7.1°, respectively. The optimal insertion angles were 47.9° ± 7.6°, 53.1° ± 10.9°, 35.0° ± 4.4°, 42.4° ± 4.9°, 60.9° ± 8.4°, 36.6° ± 5.9°, 31.2° ± 4.9°, 34.8° ± 4.6°, respectively.

Conclusion: Optimal insertion angles and safe insertion ranges varied significantly with respect to the position on the glenoid face. The safe insertion range and optimal insertion angle were found to be wider at the anterior glenoid as compared with the posterior glenoid. A posterolateral insertion angle was safer than an anterior insertion angle at the 10:30 position.

Clinical relevance: Proper arthroscopic technique resulting in anchor insertion at the correct angle, depth, and location will prevent anchor-related glenohumeral complications such as glenoid perforation, cartilage damage, persistent pain, decreased range of motion, and failure of the reconstruction.

No MeSH data available.


Related in: MedlinePlus