Anteroinferior Glenoid Defect Research Articles

Anatomical study of the limited osteotomy suture button fixation Latarjet procedure with coracoacromial ligament preservation

To investigate the morphological characteristics of the glenohumeral joint (including the glenoid and coracoid) in the Chinese population and determine the feasibility of designing coracoid osteotomy based on the preoperative glenoid defect arc length by constructing glenoid defect models and simulating suture button fixation Latarjet procedure. Twelve shoulder joint specimens from 6 adult cadavers donated voluntarily were harvested. First, whether the coracoacromial ligament and conjoint tendon connected was anatomically observed and their intersection point was identified. The vertical distance from the intersection point to the coracoid, the maximum allowable osteotomy length starting from the intersection point, and the maximum osteotomy angle were measured. Next, the anteroinferior glenoid defect models of different degrees were randomly constructed. The arc length and area of the glenoid defect were measured. Based on the arc length of the glenoid defect of the model, the size of coracoid oblique osteotomy was designed and the actual length and angle of the coracoid osteotomy were measured. A limited osteotomy suture button fixation Latarjet procedure with the coracoacromial ligament and pectoralis minor preservation was performed and the position of coracoid block was observed. All shoulder joint specimens exhibited crossing fibers between the coracoacromial ligament and the conjoint tendon. The vertical distance from the tip of the coracoid to the coracoid return point was 24.8-32.2 mm (mean, 28.5 mm). The maximum allowable osteotomy length starting from the intersection point was 26.7-36.9 mm (mean, 32.0 mm). The maximum osteotomy angle was 58.8°-71.9° (mean, 63.5°). Based on the anteroinferior glenoid defect model, the arc length of the glenoid defect was 22.6-29.4 mm (mean, 26.0 mm); the ratio of glenoid defect was 20.8%-26.2% (mean, 23.7%). Based on the coracoid block, the length of the coracoid osteotomy was 23.5-31.4 mm (mean, 26.4 mm); the osteotomy angle was 51.3°-69.2° (mean, 57.1°). There was no significant difference between the arc length of the glenoid defect and the length of the coracoid osteotomy ( P>0.05). After simulating the suture button fixation Latarjet procedure, the highest points of the coracoid block (suture loop fixation position) in all models located below the optimal center point, with the bone block concentrated in the anteroinferior glenoid defect position. The size of the coracoid is generally sufficient to meet the needs of repairing larger glenoid defects. The oblique osteotomy with preserving the coracoacromial ligament may potentially replace the traditional Latarjet osteotomy method.

Bankart Repair With Transferred Long Head of the Biceps Provides Better Biomechanical Effect Than Conjoined Tendon Transfer in Anterior Shoulder Instability With 20% Glenoid Defect

To examine the biomechanical differences between labral repair with transferred conjoined tendon and transferred long head of the biceps tendon (LHBT) for anterior shoulder instability with 20% bone loss. Twelve cadaveric shoulders were tested in sequent 5 conditions: intact, 20% glenoid defect, Bankart repair, Bankart repair with transferred conjoined tendon (dynamic conjoined tendon sling, DCS), and with transferred LHBT (dynamic LHBT sling, DLS) at 60° of glenohumeral abduction and 60° of external rotation. The physiological glenohumeral joint load was created by forces applied to the rotator cuff, conjoined tendon, and LHBT. The glenohumeral compression force and range of motion were recorded before anteroinferior force application. The anterior, inferior, and total translations were measured with 20, 30, 40, and 50 N of anteroinferior force, respectively. Anteroinferior glenoid defect led to significant increase of humerus translation and decrease of glenohumeral compression force. DLS provided better resistance effect in both anterior-posterior and superior-inferior directions than DCS under high loading condition (40 N, P=.03; 50 N, P <.01). Both DCS and DLS procedures could further restore glenohumeral compression force with Bankart repair (Bankart repair: 32.1 ± 4.0 N; DCS: 36.7 ± 3.2 N, P < .01; DLS: 35.8 ± 3.6 N, P=.03). No range of motion restrictions were observed relative to the normal shoulder. Both the DLS and DCS techniques could reduce the anterior-inferior translation and partially restore the glenohumeral stability in anterior shoulder instability with 20% anteroinferior glenoid defect compared with Bankart repair. Under greater loading conditions, DLS provides better stability than DCS. Shoulder stability can be restored by DLS and DCS with low load. With greater shoulder stability requirements, DLS might be a better option than DCS for anterior shoulder instability with 20% bone loss.

Arthroscopic iliac crest bone grafting in recurrent anterior shoulder instability: minimum 5-year clinical and radiologic follow-up

PurposeTo investigate the clinical and radiologic mid- to long-term results of arthroscopic iliac crest bone-grafting for anatomic glenoid reconstruction in patients with recurrent anterior shoulder instability.MethodsSeventeen patients were evaluated after a minimum follow-up of 5 years. Clinical [range of motion, subscapularis tests, apprehension sign, Subjective Shoulder Value (SSV), Constant Score (CS), Rowe Score (RS), Walch Duplay Score (WD), Western Ontario Shoulder Instability Index (WOSI)], and radiologic [X-ray (true a.p., Bernageau and axillary views) and computed tomography (CT)] outcome parameters were assessed.ResultsFourteen patients [mean age 31.1 (range 18–50) years] were available after a follow-up period of 78.7 (range 60–110) months. The SSV averaged 87 (range 65–100) %, CS 94 (range 83–100) points, RS 89 (range 30–100) points, WD 87 (range 25–100) points, and WOSI 70 (range 47–87) %. The apprehension sign was positive in two patients (14%). One patient required an arthroscopic capsular plication due to a persisting feeling of instability, while the second patient experienced recurrent dislocations after a trauma, but refused revision surgery. CT imaging showed a significant increase of the glenoid index from preoperative 0.8 ± 0.04 (range 0.7–0.8) to 1.0 ± 0.11 (range 0.8–1.2) at the final follow-up (p < 0.01).ConclusionArthroscopic reconstruction of anteroinferior glenoid defects using an autologous iliac crest bone-grafting technique yields satisfying clinical and radiologic results after a mid- to long-term follow-up period. Postoperative re-dislocation was experienced in one (7.1%) of the patients due to a trauma and an anatomic reconstruction of the pear-shaped glenoid configuration was observed.Level of evidenceIV.

Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods

To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. Surgeons may choose the screw type and fixation method based on preference when performing the Latarjet procedure.

Arthroscopic Bone Grafting for Anteroinferior Glenoid Defect Using Template

Significant anteroinferior glenoid bone loss is widely accepted as a major pathology of recurrent anterior shoulder dislocation, particularly after failed arthroscopic Bankart repair. Numerous surgical techniques for glenoid bone grafting have been described and have been reported to yield successful outcomes. Both open and arthroscopic approaches have been used, with the coracoid and the iliac crest being commonly used for bone graft. When compared with open surgery, an arthroscopic approach has many advantages. These include a smaller incision, better visualization, the ability to correct any concomitant pathology, and most important, preservation of the subscapularis muscle function. However, technical challenges and the steep learning curve of this complex arthroscopic procedure can be huge obstacles for shoulder arthroscopists. We describe, step by step, a simplified arthroscopic bone graft technique for repair of an anteroinferior glenoid defect using a template as a helpful tool.

Arthroscopic Implant-Free Bone Grafting for Shoulder Instability With Glenoid Bone Loss

Background: Posttraumatic anteroinferior shoulder dislocations with concomitant glenoid bone loss show high recurrence rates. The open J-bone graft technique for implant-less anatomic restoration of bony glenoid structure has previously been described, whereas results of arthroscopic techniques are currently not available. Purpose: To evaluate clinical and radiological outcome after arthroscopic anatomic reconstruction of the glenoid for recurrent anteroinferior glenohumeral instability. Study Design: Case series; Level of evidence, 4. Methods: Fifteen shoulders of 14 patients with recurrent anteroinferior shoulder instability were prospectively followed after glenoid reconstruction with a modified arthroscopic, implant-free J-bone graft. Preoperatively, the instability severity index score was documented. Patients were followed for a minimum of 2 years using the Rowe score and the Constant score. Subjective outcome was assessed using a visual analog scale (VAS) for pain and the subjective shoulder value for sports (SSVS); satisfaction with procedure outcome was also rated. Range of motion was recorded. Incidence of recurrent instability, defined as dislocation, subluxation, or persistent apprehensiveness, was documented. Pre- and postoperative (1 day and 3, 12, and 24 months) computed tomographic images were used to evaluate glenoid bone loss, reconstruction of the glenoid, and graft remodeling. Results: All preoperative scores (Rowe score: 57.6 ± 14.4; Constant score: 70.9 ± 8.9; VAS: 4.4 ± 2.6; SSVS: 31.4% ± 19.5%) were significantly (P ≤ .02) improved at final follow-up (Rowe score: 98.6 ± 1.5; Constant score: 96.3 ± 3.9; VAS: 0.2 ± 0.6; SSVS: 95.6% ± 3.8%). The preoperative glenoid area (82.1% ± 4.5%) was significantly increased immediately after surgery to 99.2% ± 6.6% (P < .001). After a physiological remodeling process, the glenoid area remained significantly increased at the latest follow-up (89.5 ± 3.2%, P < .001). J-bone grafting successfully restored glenoid concavity by significantly increasing concavity extent and depth from preoperative (19.8 ± 2.1 and 0.9 ± 0.6 mm, respectively) to postoperative (24.0 ± 2.1 and 2.1 ± 0.8 mm, respectively) (P < .001). There were no recurrent instabilities. One traumatic graft fracture occurred during the follow-up period. Conclusion: The arthroscopic J-bone graft technique permits minimally invasive reconstruction of anteroinferior glenoid defects and provided excellent early clinical outcome without recurrent instability in posttraumatic shoulder dislocations. A physiological remodeling process leads to restoration of a more natural glenoid anatomy.

The intra- and inter-observer reliability of the CT-scan based X index to quantify glenoid bone loss in chronic anterior shoulder instability and its impact on decision making.

The X index is a measure of the antero-inferior glenoid bone loss on unilateral 2D CT-scans in the preoperative analysis of chronic anterior shoulder instability. Recurrence rate was shown to be higher after stabilization surgery if X index is superior or equal to 0.4. The objective of this study was to assess the intra- and inter-observer reliability of the X index. Sixty patients with an X index ≥0.4 were included retrospectively. The X index was measured twice by two independent evaluators, 15 days apart. The measurement was performed on a unilateral 2D CT-scan by dividing the length of the antero-inferior glenoid defect over the maximal antero-posterior diameter of the glenoid. Reliability of X index was assessed with intra-class correlation coefficient (ICC, ρ). Two points were added to the ISIS calculation if its glenoid criterion was "zero" and we compared this modified score to the original one. The intra-observer reliability of the X index measurement was "excellent" (ρ = 0.95 ± 0.01, p < 0.0001) while the inter-observer reliability was "good" (ρ = 0.59 ± 0.08, p < 0.0001). In patients with a glenoid bone loss visualized by the X index, 48.3 % had a negative sclerotic glenoid line sign. This proportion significantly decreased with the augmentation of the X index, p = 0.02. The average original ISIS score was 3.4 ± 1.9 and became 4.3 ± 1.7 (p < 0.00001) when the X index was incorporated. The X index is a reliable and simple unilateral 2D CT-scan measurement. AP shoulder radiographs significantly underestimated glenoid bony lesions.

Arthroscopic anatomic glenoid reconstruction using an autologous iliac crest bone grafting technique

Open bone block procedures for glenohumeral stabilization have been used for a long time. With the advancement of arthroscopic techniques and the development of sophisticated instruments and implants, the insertion of the bone block can be performed by an all-arthroscopic approach. The purpose of this study was to evaluate the clinical and radiologic results after an arthroscopic anatomic glenoid reconstruction using an all-arthroscopic, autologous tricortical iliac crest bone grafting technique. Fifteen patients (1 female and 14 male patients; mean age, 31.4 years [range, 17-49 years]) underwent reconstruction of significant glenoid defects in cases of recurrent shoulder instability by the aforementioned technique. The patients were followed up clinically (range of motion, Constant score, Rowe score, Subjective Shoulder Value, and Western Ontario Shoulder Instability Index) and radiographically (with true anteroposterior and axillary views, as well as 2-/3-dimensional computed tomography [glenoid configuration, signs of graft resorption, bone consolidation, and glenoid index]). After a mean follow-up period of 20.6 months (range, 12-65 months), the Constant score averaged 85.0 points (range, 73-98 points; contralateral side, 89.6 points [range, 78-96 points]), the Rowe score averaged 88.0 points (range, 65-100 points), the Subjective Shoulder Value averaged 84.5% (range, 50%-100%), and the Western Ontario Shoulder Instability Index averaged 76.7% (range, 46%-93%). No recurrent subluxations or dislocations were observed. Radiographically, computed tomography imaging showed a consolidated autograft in all cases. The glenoid index increased from a mean of 0.77 preoperatively to 1.16 immediately postoperatively; at the time of last follow-up, the glenoid index decreased to 1.04. The arthroscopic reconstruction of anteroinferior glenoid defects re-creates the pear-shaped anatomy of the anteroinferior glenoid and leads to good to excellent early clinical results.

Repair of an Anteroinferior Glenoid Defect by the Latarjet Procedure: Quantitative Assessment of the Repair by Computed Tomography

The purpose of this study was to determine quantitatively whether the Latarjet procedure (coracoid transfer to the glenoid) is sufficient to restore a significant defect area of the glenoid. Fourteen cadaveric shoulders were used (mean age, 76 years; range, 72 to 87 years). An anteroinferior glenoid defect was created and then the coracoid osteotomized to its angle and transferred to the defect. A 3-dimensional computed tomography scan was used to calculate the surface area of (1) the intact glenoid, (2) the osteotomized glenoid, and (3) the reconstructed glenoid. The mean area of the intact inferior glenoid was 734 +/- 89 mm(2). After creation of the defect, the surface area of the glenoid was reduced significantly to 523 +/- 55 mm(2) (P = .011). The mean defect area was 28.7% +/- 6% of the intact glenoid. After coracoid transfer, the mean surface area of the reconstructed glenoid was 708 +/- 71 mm(2) but it was not significantly smaller than that of the intact glenoid (P = .274). The mean surface area of the coracoid that was used to repair the defect was 198 +/- 34 mm(2), or 27% +/- 5% of the intact glenoid. In our cadaveric model, a mean 29% defect size of the inferior glenoid was restored to normal after coracoid transfer by use of the Latarjet procedure. In the clinical scenario, the existence of a glenoid bone defect of more than 25% to 30% is very rare in patients with anterior shoulder instability. Therefore, when clinically indicated, large bony defects of the anterior glenoid can be adequately treated by the Latarjet procedure.

Effect of an Anterior Glenoid Defect on Anterior Shoulder Stability

Background There have been few biomechanical studies to clarify which size of a glenoid defect is critical. However, those studies have assumed that the defect occurred anteroinferiorly. Recent studies have reported that the defect is located anteriorly rather than anteroinferiorly. Therefore, the effect of the anterior, not anteroinferior, glenoid defect on shoulder stability needs to be investigated. Hypothesis The anterior glenoid defect would have a similar effect on anterior shoulder stability as that of the anteroinferior glenoid defect. Study Design Controlled laboratory study. Methods Eight fresh-frozen cadaveric shoulders were used (mean age, 74 years). The specimen was attached to a shoulder-testing device with the arm in abduction and external rotation. An osseous defect was created stepwise with a 2-mm increment of the defect width. The stability ratio was used to evaluate joint stability. With a 50-N axial force, the translational force applied to the humeral head was measured by a force transducer. Results The stability ratio without a defect (32% ± 6%) significantly decreased after creating a 6-mm defect (17% ± 5%; P = .0001), which was equivalent to 20% of the glenoid length. Conclusion An osseous defect at 3 o'clock with a width that was equal to or greater than 20% of the glenoid length significantly decreased anterior stability. Clinical Relevance The results suggest that reconstruction of the glenoid concavity might be necessary in shoulders with an anterior glenoid defect of at least 20% of the glenoid length.

Open Shoulder Repair of Osseous Glenoid Defects

Background To address glenoid bone deficiency, 2 competing surgical approaches are currently recommended: transplantation of a structural bone graft or the coracoid transfer according to Latarjet. Nonetheless, no clear advantages for either procedure are evident. Hypothesis The Latarjet procedure will provide an equivalent beneficial effect on glenohumeral stability as the placement of an intra-articular bone graft. Study Design Controlled laboratory study. Methods Stability testing of 8 cadaveric shoulders was performed in a dynamic shoulder simulator under 4 different conditions: (1) anteroinferior capsulotomy, (2) anteroinferior glenoid defect, (3) transplantation of a contoured bone graft, and (4) Latarjet procedure. Translational movement of the humeral head in response to a load of 25 N was evaluated in the anterior and anteroinferior directions. Results The Latarjet procedure significantly reduced translation by 354% relative to the glenoid defect condition at 30° of abduction and by 374% at 60° of abduction. In comparison, the bone graft significantly reduced translation by 179% at 30° of abduction and by 159% at 60° of abduction. The effect of the bone graft was lowest in external rotation at 60° of abduction where a decrease of translation of 133% was observed. Comparing both reconstruction techniques, the Latarjet procedure resulted in significantly less anterior and anteroinferior translation at 60° of abduction. Conclusion Biomechanically, the Latarjet procedure outperforms the bone graft in reducing translation in anteroinferior glenoid bone defects. The advantage of the Latarjet procedure is particularly evident at 60° of glenohumeral abduction. Clinical Relevance On the basis of the results of this biomechanical study, the authors recommend the Latarjet procedure for restoring stability in shoulders with a significant glenoid bone defect.

Arthroscopic reconstruction of chronic anteroinferior glenoid defect using an autologous tricortical iliac crest bone grafting technique

Only a few reports exist on the management of severe anteroinferior glenoid defects in case of recurrent shoulder instability most of them including open approaches. We describe an all-arthroscopic reconstruction technique of the anteroinferior glenoid that includes an autologous iliac crest bone grafting using bio-compression screws and a capsulolabral repair using suture anchors. This technique recreates the bony and soft-tissue anatomy of the anteroinferior glenoid while preserving the integrity of insertion of the subscapularis (SSC) tendon.

Quantification of a glenoid defect with three-dimensional computed tomography and magnetic resonance imaging: A cadaveric study

Bone loss of the glenoid is a common finding in anterior glenohumeral instability. Several methods to measure the size of a glenoid defect have been described but have not been validated. In this study, 14 cadaver glenoids with a randomly created anteroinferior glenoid defect were used for validation of the so-called circle method. Measurements were done by 2 researchers on digital photographs, 3-dimensional (3D) computed tomography (CT) scans, and magnetic resonance images (MRI). The correlation coefficient (r(2)) for comparing measurements from the digital photographs with the CT scans was 0.97 for researcher 1 and 0.90 for researcher 2. When they compared digital images with MRI, the r(2) was 0.93 for researcher 1 and 0.92 for researcher 2. No statistical differences were found between the 2 researchers. The circle method is a simple method for preoperative quantification of a glenoid defect. Measurements can be done with 3D CT scans as well as MRI.

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Introduction: Glenohumeral instability associated with a significant osseous defect of the glenoid is often treated with bone graft to restore the glenoid concavity. The purpose of this study is to investigate the effects on the intrinsic stability provided by the glenoid of (1) a standardized anteroinferior glenoid defect and (2) different heights and configurations of anteroinferior glenoid bone graft. Methods: Utilizing a tipping device to measure the balance stability angle, the anteroinferior stability provided by the glenoid concavity was assessed in each of four fresh frozen, grossly normal cadaver glenoids in (1) the unaltered state, (2) after creating a standardized defect of a magnitude reported by other investigators to be sufficient to require a bone graft, and (3) after a succession of steps varying the bone graft height and contour.

Anteroinferior Bone-Grafting Can Restore Stability in Osseous Glenoid Defects

Glenohumeral instability associated with a large osseous defect of the glenoid can be treated with bone graft to restore the glenoid concavity. The shape and positioning of the graft is critical: a graft that encroaches on the extrapolated glenoid curvature can prevent the head from seating completely in the glenoid, whereas a graft that is too far from the curvature does not restore the glenoid concavity. The purpose of the present study was to investigate how the intrinsic stability that is provided by the glenoid is affected by (1) a standardized anteroinferior glenoid defect and (2) different configurations of anteroinferior glenoid bone graft. The anteroinferior stability provided by the glenoid was quantitated by measuring the balance stability angle in that direction. The balance stability angle is the maximal angle that the direction of the net humeral joint-reaction force can make with the glenoid centerline before dislocation takes place. The anteroinferior stability was assessed in each of four fresh-frozen, grossly normal cadaveric glenoids in (1) the unaltered state, (2) after the creation of a standardized defect of a magnitude that has been reported by other investigators to be sufficient to require a bone graft, and (3) after each step of a series of bone-grafting procedures involving grafts of varying height and contour. The anteroinferior glenoid defect significantly diminished the anteroinferior stability by almost 50% (p = 0.006). Bone-grafting significantly increased the stability provided by the glenoid. The increase in stability as compared with that of the glenoid with the standardized defect was particularly marked for contoured graft heights of 6 and 8 mm, for which the increases were 150% (p = 0.0001) and 229% (p < 0.00025), respectively. Contouring of the graft minimized the potential for unwanted contact between the ball and the graft. Anteroinferior shoulder instability caused by an osseous defect in the glenoid can be corrected with bone-grafting. The effectiveness of the graft in restoring the lost stability is related both to its height and to the extent to which it is contoured as long as the graft is not so prominent that it forces the ball posteriorly from the center of the glenoid.

ANTEROINFERIOR BONE-GRAFTING CAN RESTORE STABILITY IN OSSEOUS GLENOID DEFECTS

Background: Glenohumeral instability associated with a large osseous defect of the glenoid can be treated with bone graft to restore the glenoid concavity. The shape and positioning of the graft is critical: a graft that encroaches on the extrapolated glenoid curvature can prevent the head from seating completely in the glenoid, whereas a graft that is too far from the curvature does not restore the glenoid concavity. The purpose of the present study was to investigate how the intrinsic stability that is provided by the glenoid is affected by (1) a standardized anteroinferior glenoid defect and (2) different configurations of anteroinferior glenoid bone graft. Methods: The anteroinferior stability provided by the glenoid was quantitated by measuring the balance stability angle in that direction. The balance stability angle is the maximal angle that the direction of the net humeral joint-reaction force can make with the glenoid centerline before dislocation takes place. The anteroinferior stability was assessed in each of four fresh-frozen, grossly normal cadaveric glenoids in (1) the unaltered state, (2) after the creation of a standardized defect of a magnitude that has been reported by other investigators to be sufficient to require a bone graft, and (3) after each step of a series of bone-grafting procedures involving grafts of varying height and contour. Results: The anteroinferior glenoid defect significantly diminished the anteroinferior stability by almost 50% (p = 0.006). Bone-grafting significantly increased the stability provided by the glenoid. The increase in stability as compared with that of the glenoid with the standardized defect was particularly marked for contoured graft heights of 6 and 8 mm, for which the increases were 150% (p = 0.0001) and 229% (p < 0.00025), respectively. Contouring of the graft minimized the potential for unwanted contact between the ball and the graft. Conclusions: Anteroinferior shoulder instability caused by an osseous defect in the glenoid can be corrected with bone-grafting. The effectiveness of the graft in restoring the lost stability is related both to its height and to the extent to which it is contoured as long as the graft is not so prominent that it forces the ball posteriorly from the center of the glenoid.