Latarjet Procedure for Instability with Bone Loss



Latarjet Procedure for Instability with Bone Loss


Patrick J. Denard

Stephen S. Burkhart





ANATOMY



  • In 1954, Latarjet14 described his technique for a coracoid bone graft to prevent anterior dislocation.



    • He detached the pectoralis minor from the coracoid, incised the coracoacromial ligament, left a stump of the coracoacromial ligament attached to the coracoid, then completed the osteotomy at the base of the coracoid so that it could be placed as a bone graft against the anterior glenoid neck.


    • The coracoid was passed through a split in the subscapularis and positioned so that its inferior surface was in contact with the anterior glenoid neck where it was secured with two screws (FIG 3). In doing so, the posterolateral surface of the coracoid was placed adjacent to the glenoid joint surface.


  • We call our surgical technique the congruent arc technique. This technique was first reported by Burkhart and DeBeer5 in 2000 and incorporated two important modifications:



    • The coracoid graft was rotated 90 degrees around its long axis so that the concave inferior surface of the coracoid became the extension to the glenoid concavity, providing
      a much more anatomic articular arc to the reconstructed glenoid surface11 (FIG 4).






      FIG 2A. Normal relationship of the glenoid and humeral articular surfaces. B. Full external rotation still maintains contact between the humeral and glenoid articular surfaces. C. Large Hill-Sachs lesion creates an articular arc length mismatch. D. A small amount of external rotation will cause the Hill-Sachs lesion to engage the anterior corner of the glenoid. (Reproduced with permission from Burkhart SS, Lo IK, Brady PC. Burkhart’s View of the Shoulder: The Cowboy’s Guide to Advanced Shoulder Arthroscopy. Philadelphia: Lippincott Williams & Wilkins, 2006.)


    • The capsule was reattached to the native glenoid by means of suture anchors so that the coracoid graft was extraarticular, thereby preventing abrasion of the humeral articular surface against the coracoid graft.


    • Use of the congruent arc technique, or the inferior aspect of the coracoid extending the glenoid, more closely restores normal glenohumeral contact forces compared to the posterolateral position described by Latarjet.11






FIG 3 • Schematic of the French technique for Latarjet reconstruction. A. Sagittal and (B) axial schematics prior to Latarjet reconstruction. C,D. The coracoid is osteotomized, and the undersurface of the coracoid is fixed directly to the glenoid. The contour of the coracoid graft does not match the contour of the native glenoid. G, glenoid; H, humerus. (Reproduced with permission from Burkhart SS, Lo IK, Brady PC, et al. The Cowboy’s Companion: A Trail Guide for the Arthroscopic Shoulder Surgeon. Philadelphia: Lippincott Williams & Wilkins, 2012.)


PATHOGENESIS



  • Bone lesions are present in up to 95% of patients with recurrent shoulder instability.10


  • Examining the glenoid alone, Sugaya et al19 reported that 90% of patients with recurrent instability have glenoid bone
    abnormalities (including bone loss or abnormal contour). Glenoid bone loss (distinct from abnormal contour alone) was seen in 50% of cases in over half of which the defect was greater than 5% of the glenoid width.






    FIG 4 • Schematic of the Burkhart-DeBeer modification of the Latarjet reconstruction. A. Sagittal view demonstrates glenoid bone loss. The undersurface of the coracoid is shaded in blue. B. Following coracoid osteotomy, the graft is rotated 90 degrees so the undersurface of the coracoid is flush with the glenoid and forms a continuation of the concave glenoid articular arc. The graft is secured with two screws. C. Axial view demonstrates how the orientation change (compared to the original French technique [FIG 3]) provides a contour that more closely matches the native glenoid concavity and also provides greater length extension of the articular arc. G, glenoid; H, humerus. (Reproduced with permission from Burkhart SS, Lo IK, Brady PC, et al. The Cowboy’s Companion: A Trail Guide for the Arthroscopic Shoulder Surgeon. Philadelphia: Lippincott Williams & Wilkins, 2012.)


  • Yamamoto et al20 introduced the concept of the “glenoid track” to describe the interaction between glenoid bone loss and Hill-Sachs lesions.



    • When the arm is raised, the glenoid contact area shifts from the inferomedial to the superolateral portion of the posterior articular surface of the humeral head, creating a zone of contact (glenoid track) between the glenoid and the humeral head. An intact glenoid track results in bony stability.



      • In cases with 25% or greater glenoid bone loss, bony stability is always compromised and bony augmentation is required.


      • In cases with less than 25% glenoid bone loss, the “glenoid track” can be used to define the Hill-Sachs lesion as “on track” or “off track” and therefore determine the need for remplissage in addition to arthroscopic Bankart repair.


NATURAL HISTORY



  • In the setting of glenoid bone loss 25% or greater of the inferior glenoid diameter, recurrence following arthroscopic Bankart repair is 67% to 75%.3,5 In such cases, recurrence can be dramatically reduced by the Latarjet procedure in which the coracoid is transferred to the glenoid.


PATIENT HISTORY AND PHYSICAL FINDINGS



  • A thorough history is essential and should elicit the mechanism of injury and prior treatments received.



    • Previous operative reports should be obtained and reviewed; they often yield valuable information about areas of bone deficiency, tissue quality, and fixation devices used.


    • Essential components of the history include age, mechanism of dislocations, number of dislocations, position of shoulder during dislocation, reduction efforts (self- or physician reduced), hand dominance, sport and work requirements, prior treatments, and patient’s goals.


  • The physical examination determines the position and direction of instability as well as identifies or eliminates factors that contribute to instability:



    • Muscle tone or wasting


    • Range of motion, active and passive


    • Strength assessment (rule out concomitant rotator cuf tear)


    • Position of apprehension


    • Relocation relief


    • Direction of instability (load and shift test)


    • Generalized ligamentous laxity


    • Neurovascular examination


IMAGING AND OTHER DIAGNOSTIC STUDIES



  • Our evaluation for bone loss is based on preoperative and intraoperative assessments. We routinely obtain anteroposterior (AP), transscapular lateral, and axillary radiographs of the glenohumeral joint. Radiographs are evaluated on all patients for the presence of glenoid bone loss or a Hill-Sachs lesion.


  • Although plain radiographs can grossly demonstrate bone defects, the severity is often underestimated. We therefore obtain a computed tomography (CT) scan with three-dimensional (3-D) reconstructions on all individuals with suspected bone loss. Additionally, we have a low threshold
    for obtaining a CT in patients without plain radiographic evidence of bone loss but otherwise have risk factors for recurrence (eg, young patients, multiple dislocations). To estimate glenoid bone loss, bilateral 3-D CTs are obtained.


  • Assuming a normal contralateral shoulder, the percentage of bone loss is easily estimated by comparing the width of the glenoid on the affected side to the width of the glenoid on the normal shoulder in the en face view. In 96% of cases, this technique accurately stratifies glenoid bone loss as less than or greater than 25% of glenoid width.9


DIFFERENTIAL DIAGNOSIS



  • Multidirectional instability


  • Seizure disorders


NONOPERATIVE MANAGEMENT



  • There are few indications for nonoperative management of glenoid bone loss 25% or greater.


  • However, uncontrolled seizure disorders must be recognized and may be contraindication to Latarjet reconstruction based on the high failure rate with this condition.18


  • In addition, infection and voluntary instability are contraindications to Latarjet reconstruction.


SURGICAL MANAGEMENT

Jul 24, 2016 | Posted by in ORTHOPEDIC | Comments Off on Latarjet Procedure for Instability with Bone Loss

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