GLENOIDBONELOSS:WHAT
ISITANDHOWTO
OPTIMIZEARTHROSCOPIC
SUCCESS?
Nikhil N. Verma, MD; Sanjeev Bhatia, MD MidwestOrthopaedicsatRUSH
Chicago,IL
Why is glenoid bone loss important?
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Bone defects greater than 6‐8mm or 21% of inferior glenoid surface area dramatically compromise intrinsic osseous restraints of glenohumeral joint.3, 5, 6, 9 and contributing to recurrent instability or failed surgery In the acute setting (< 3 months) after initial injury resulting in a bony Bankart, fracture fragments of anterior glenoid may still be present. As instability becomes chronic (>6 months), bone fragments resorb and result in erosive bone loss: Bone loss as seen on 3D CT scan. Bone loss is classified as (A) acute, (B) partial attritional, or (C) chronic attritional.3 Bone Loss
Potentiates
Bone Loss
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How do Hill-Sachs Lesions occur8?
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Soft bone of humeral head impacts hard glenoid Not the Bare Spot of the humerus o 95% of time near infraspinatus and articular margin o Edwards, Boulahia, Walch. Arthroscopy 2003 Where do Hill-Sachs lesions occur?
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Posterolateral location  “Orange‐slice” Shape (Saito et al. 2009 Arch Orthop Trauma Surg) What Imaging Modalities are Useful?
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Initial plain films are a must, but often they fail to illustrate the true degree of bone loss o AP, True AP shoulder, Axillary and Scapular Y o Axillary best for visualizing bone loss o Apical oblique view, West Point view and Didiee view best 3D CT scan most helpful o Scapula and glenoid can be visualized as free body after humeral head digitally subtracted o Axial cuts can be used to visualize and estimate hill sachs lesion o Indications for obtaining 3D CT scan: ‐
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MRI also helpful for visualization of co‐pathologies o Cuff tears o SLAP tears o HAGL/ALPSA lesions o MRI is generally inferior to 3D CT scan for quantification of bone loss Why is Bone Loss Quantification Important?
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Treatment algorithm predicated on amount of bone loss! Quantification of Humeral and Glenoid Bone Defects 0‐20% Hill‐Sachs
Moderate 20‐30% Hill‐Sachs only
>30% Hill‐Sachs
Combined glenoid and engaging humeral defect
Soft tissue arthroscopic Bankart repair
Remplissage and Arthroscopic Bankart repair
Humeral osteochondral allograft or humeral resurfacing
Glenoid Bony Reconstruction How to quantify bone loss?
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Numerous methods, but inaccuracies still are common given irregular shape of glenoid Most bone loss quantification methods are predicated on fact that inferior 2/3 of glenoid can be modeled as a circle5, 8 Thus, best method for quantification is one in which defect surface area is digitally measured and then divided by area of best‐fit circle o Defect surface area can be inferred as “missing area” in best‐fit circle o Given irregular shape, digitally measuring this area is most accurate as opposed to using a Diameter based scheme.8, 10 o Can have radiologist digitally measure if they have specialized software o
Image J (http://rsb.info.nih.gov/ij/), a public domain Java image processing program that is freely available from the National Institute of Health (NIH), has been shown to be extremely effective at measuring area of elliptical or irregularly shaped selections2, 7, 11
Diameter Based Bone Loss Quantification: Easy to do but inherently inaccurate
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The diameter of the inferior glenoid has routinely been described as a simple and easy way to quantify bone loss, both on CT and Arthroscopically To perform, simply measure the width of the bone defect and divide by the diameter of the inferior glenoid circle The problem is, the true geometric calculation of the area of a circular segment (analogous to bone defect on a circle) is far more complex: ‐
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The diameter equation actually overestimates bone loss at all values of w (width) except when w is 0 and 50% of the diameter (Bhatia S, Romeo AA et al. Glenoid Diameter is an Inaccurate Method for Glenoid Bone Loss Quantification. 2013 AANA Annual Meeting). o The commonly used diameter equation overestimated true glenoid bone loss at all values of w (width) except when w was 0% and 50% of the diameter, D. Mean overestimation error was 3.9±1.9% (range 0.0‐5.8%). Interestingly, maximal error in the Diameter based equation occurred when defect width (w) was 20% of the diameter (D) At this value, w/D x 100% (Diameter equation) predicted 20% bone loss when true bone loss was actually 14.2% Defects must be evaluated in a combined fashion.
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Glenoid Track Concept (Yamamoto, Itoi et al. JSES 2007) o If there is glenoid BONE LOSS  Hill Sachs more important o Engagement of Hill‐Sachs occurs more easily o Bipolar problem Arthroscopic Management
Tips for Successful arthroscopic repair:
Keys to success o
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Complete recognition and treatment of anterior glenoid/labrum pathology Pathologic laxity of AIGHL Capsulo‐labral repair and appropriate tensioning Recognition of ALL labral pathology – SLAPs, Posterior labral tear extension Posterior plication versus anchor repair if indicated Rotator interval closure arthroscopically if indicated – probably reduces anterior translation ‐ caution to lose ER. o
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Good preoperative workup – Attritional glenoid loss – Consider Open Bony Bankart – Arthroscopic incorporation of glenoid fragment How to Treat Hill-Sachs Lesions: KEY IS PREVENTING ENGAGEMENT!
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Soft Tissue Interposition‐ “Remplissage” Lengthen articular arc of humerus Autograft Allograft Synthetic Plugs Humeroplasty Partial resurfacing In rare situations, treatment of both glenoid and humerus may be necessary 1) Remplissage a. Arthroscopic or open b. Insetting of the infraspinatus tendon and posterior joint capsule in to the Hill‐Sachs defect c. Converts an intra‐articular defect in to an anatomically extra‐articular position d. May limit external rotation e. Technique dependent (inset adjacent tissue, excessive medial tissue grasping results in functional shortening of posterior rotator cuff and restricted external rotation) [Image from George Athwal Personal File] f.
Technique i. Bankart preparation 1. Insert and pass Bankart repair suture anchors and sutures 2. Park passed sutures, do not tie yet ii. Hill‐Sachs preparation 1. View from anterior 2. Debride Hill‐Sachs lesion with burr/resector iii. Subacromial bursectomy (posterior) iv. Remplissage 1. Anterior viewing 2. Insert anchors percutaneously, using spinal needle localization [Image from George Athwal Personal File] [Image from George Athwal Personal File] 3. Create mattress sutures with penetrating suture passer inserted percutaneously [Images from George Athwal Personal File] 4. Penetrate tissue immediately adjacent to Hill‐Sachs defect [Image from George Athwal Personal File] 5. Tie sutures in subacromial space v. Intra‐articular view (anterior) 1. Assess insetting [Image from George Athwal Personal File] vi. Intra‐articular view (posterior) 1. Tie Bankart sutures References 1. 2. 3. 4. Baudi P, Righi P, Bolognesi D, et al. How to identify and calculate glenoid bone deficit. La Chirurgia degli organi di movimento. 2005;90(2):145‐152. Bhatia S, Bell R, Frank RM, et al. Bony incorporation of soft tissue anterior cruciate ligament grafts in an animal model: autograft versus allograft with low‐dose gamma irradiation. The American journal of sports medicine. 2012;40(8):1789‐1798. Bhatia S, Ghodadra NS, Romeo AA, et al. The importance of the recognition and treatment of glenoid bone loss in an athletic population. Sports health. 2011;3(5):435‐440. Gerber C, Nyffeler RW. Classification of glenohumeral joint instability. Clinical orthopaedics and related research. 2002(400):65‐76. 5. 6. 7. 8. 9. 10. 11. Huysmans PE, Haen PS, Kidd M, Dhert WJ, Willems JW. The shape of the inferior part of the glenoid: a cadaveric study. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. 2006;15(6):759‐763. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. The Journal of bone and joint surgery. American volume. 2000;82(1):35‐46. Patzkowski JC, Kirk KL, Orr JD, Waterman BR, Kirby JM, Hsu JR. Quantification of posterior ankle exposure through an achilles tendon‐splitting versus posterolateral approach. Foot & ankle international. / American Orthopaedic Foot and Ankle Society [and] Swiss Foot and Ankle Society. 2012;33(10):900‐904. Piasecki DP, Verma NN, Romeo AA, Levine WN, Bach BR, Jr., Provencher MT. Glenoid bone deficiency in recurrent anterior shoulder instability: diagnosis and management. The Journal of the American Academy of Orthopaedic Surgeons. 2009;17(8):482‐493. Provencher MT, Bhatia S, Ghodadra NS, et al. Recurrent shoulder instability: current concepts for evaluation and management of glenoid bone loss. The Journal of bone and joint surgery. American volume. 2010;92 Suppl 2:133‐151. Sugaya H, Moriishi J, Dohi M, Kon Y, Tsuchiya A. Glenoid rim morphology in recurrent anterior glenohumeral instability. The Journal of bone and joint surgery. American volume. 2003;85‐
A(5):878‐884. Terryn C, Sellami M, Fichel C, et al. Rapid method of quantification of tight‐junction organization using image analysis. Cytometry. Part A : the journal of the International Society for Analytical Cytology. 2013;83(2):235‐241.