Current Evidence and Techniques for Arthroscopic Bone Augmentation.

The indications for bone block augmentation of the glenoid following recurrent anterior shoulder instability are expanding. Arthroscopic anatomic glenoid reconstruction (AAGR) is an evolving technique with similar clinical results to the Latarjet procedure and other open bone block procedures. Multiple types of bone grafts and fixation techniques have been described, with varying results on bony integration, resorption, articular congruity, and recurrence rates. This review focuses on biomechanics, patient workup, indications, current evidence, and the authors' preferred surgical technique for AAGR.

Clinical and radiographic outcomes of primary vs. revision arthroscopic anatomic glenoid reconstruction with distal tibial allograft for anterior shoulder instability with bone loss.

BACKGROUND: The purpose of this study was to assess the clinical and radiographic outcomes of arthroscopic anatomic glenoid reconstruction (AAGR) used for primary vs. revision surgery for addressing anterior shoulder instability with bone loss. METHODS: We performed a retrospective review on consecutive patients who underwent AAGR from 2012 to 2020. Patients who received AAGR for anterior shoulder instability with bone loss and had a minimum follow-up of 2 years were included. Exclusion criteria included patients with incomplete primary patient-reported outcome scores (PROs), multidirectional instability, glenoid fracture, nonrigid fixation and concomitant humeral avulsion of the glenohumeral ligament, or rotator cuff repair. Our primary outcome was measured using the Western Ontario Shoulder Instability Index (WOSI) scores. Secondary outcomes included postoperative Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) scores, complications, recurrence of instability and computed tomographic (CT) evaluation of graft position, resorption, and healing. RESULTS: There were 73 patients (52 primary and 21 revision) finally included. Both groups had comparable demographics and preoperative WOSI and DASH scores. The primary group had significantly better postoperative WOSI and DASH scores at final follow-up when compared to the revision group (WOSI: 21.0 vs. 33.8, P = .019; DASH: 7.3 vs. 17.2, P = .001). The primary group also showed significantly better WOSI scores than the revision group at the 6-month, 1-year, and 2-year time points (P = .029, .022, and .003, respectively). The overall complication rate was 9.6% (5 of 52) in the primary group and 23.8% (5 of 21) in the revision group. Both groups showed good graft healing and placement in the anterior-to-posterior and mediolateral orientation and had a similar rate of graft resorption and remodeling. There was no difference between the groups in the remainder of the CT measurements. CONCLUSION: Functional outcome scores and stiffness were significantly worse in patients undergoing an AAGR procedure after a failed instability surgery when compared with patients undergoing primary AAGR. There were no differences in postoperative recurrence of instability or radiographic outcomes. As a result, AAGR should be considered as a primary treatment option within current treatment algorithms for shoulder instability.

Arthroscopic anatomic glenoid reconstruction has a lower rate of recurrent instability compared to arthroscopic Bankart repair while otherwise maintaining a similar complication and safety profile.

OBJECTIVES: The primary purpose of this study was to determine the frequency and type of complications, including subluxation, infection, hardware complication, graft/glenoid fracture, chondrolysis, neurovascular deficits and stiffness following an Arthroscopic Bankart Repair (ABR) or an Arthroscopic Anatomic Glenoid Reconstruction (AAGR) using a distal tibia allograft for recurrent anterior shoulder instability. Secondary purposes were to determine the frank dislocation rate and the associations of post-operative complications with demographic patient factors. METHODS: Demographic and clinical data were reviewed using means ± standard deviations or frequencies in patients with recurrent anterior shoulder instability who underwent either an ABR or an AAGR. Post-operative patient records were analysed to identify any post-operative complications. The numerical variables of the two groups were compared using the independent t-test or Mann-Whitney U test. Categorical variables and complications were tested using the chi-square test, Fisher's exact test, or the two-sided Monte Carlo test with a significance level of 0.05. RESULTS: We included 174 patients in this cohort, with 61.5% of patients receiving ABR and 38.5% receiving AAGR. Most of our patients were male (70.1%) with an average age of 23.41 ± 8.26 years in the ABR group and 29.37 ± 13.54 years in the AAGR group (p = 0.001). The two groups were similar with respect to their post-operative complication rates when excluding frank dislocation (ABR: 11%, AAGR: 12%). The AAGR group had statistically significantly higher rates of hardware removal compared to the ABR group (p = 0.004). The ABR group had 25 post-operative frank dislocations, with none reported in the AAGR cohort (p < 0.001). The total complication rate for each procedure was found to be 35% for ABR and 12% for AAGR. CONCLUSION: AAGR has a comparable safety profile to the ABR when assessing post-operative complications such as subluxation, infection, graft/glenoid fracture, chondrolysis, neurovascular deficits and stiffness. AAGR is superior to ABR with respect to rates of recurrent instability and should be considered as a first-line treatment in certain patients with specific risk factors such as younger age, competitive contact sports participation, and higher number of instability events pre-operatively. LEVEL OF EVIDENCE: Level III.

Donor-Specific Human Leukocyte Antigen Antibody Formation After Allograft Glenoid Reconstruction Occurs But Does Not Impact Clinicoradiographic Outcomes.

BACKGROUND: Recurrent shoulder instability is a prevalent condition, with glenoid bone loss as a common cause. Arthroscopic repair using distal tibial allografts provides long-lasting treatment by restoring glenoid surface area and presumably avoids risks of sensitization against donor human leukocyte antigen (HLA). Two case studies have challenged this assumption, suggesting that small bone allografts are able to induce host adaptive immune responses to donor HLA. The incidence of small bone allograft HLA sensitization and its effects on resorption and patient outcomes are unclear. PURPOSE/HYPOTHESIS: The purpose was to assess the rate of sensitization against donor HLA after distal tibial allograft procedures for shoulder instability due to glenoid bone loss and to find whether HLA sensitization negatively affects patient-reported and radiographic outcomes. We hypothesized that sensitized patients would have worse radiographic and self-reported outcomes compared with nonsensitized patients. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 71 patients with a mean age of 28.85 years (range, 13.58-61.31 years) were enrolled, with 58 patients submitting sufficient pre- and postoperative blood samples for HLA antibody testing. In patients who developed HLA antibodies postoperatively, donor HLA typing was used to confirm donor-specific sensitization. Pre- and postoperative computerized tomography scans (0.9 ± 0.8 years follow-up) were used to grade resorption based on the modified Zhu resorption grade classification (ie, grade 0 = no resorption; grade 1 = less than 25% resorption; grade 2 = between 25% and 50% resorption; and grade 3 = larger than 50% resorption). The Western Ontario Shoulder Instability Index outcome scores were obtained preoperatively and at regular postoperative appointments. Resorption and outcome data were compared between sensitized and nonsensitized patients using the Fisher exact test, independent 2-tailed Student t tests, and the Wilcoxon rank-sum test to determine the effect of HLA sensitization on radiographic and patient-reported outcomes. RESULTS: A total of 7 (12.1%) patients with sufficient HLA samples were sensitized against donor HLA postoperatively. Sensitized patients did not have significantly higher rates of resorption (21.9% vs 14.3%, 21.9% vs 28.6%, 43.8% vs 28.6%, and 12.5% vs 28.6% for respective resorption grades 0-3; P = .67; α = .05). Self-reported outcomes were not statistically significant between sensitized and nonsensitized patients (24.9 ± 27.61 vs 40.16 ± 18.99; P = .37; α = .05) and did not differ significantly based on resorption grade (47.4 ± 0.0 vs 55.2 ± 18.8, 30.4 ± 15.8 vs 39.9 ± 20.9, 41.2 ± 0.0 vs 39.1 ± 13.1, and -24.9 ± 0 vs 24.4 ± 19.6 for resorption grades 0-3; P > .05; α = .05). CONCLUSION: Sensitization against donor HLA after small bone graft allografting was not previously considered but has been brought to light as a possibility. Aside from potential complications for future organ transplants, HLA sensitization does not introduce a risk for adverse outcomes or higher grades of resorption compared with nonsensitized patients after small bone allografting for shoulder instability.

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

PURPOSE: To 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. METHODS: Seventeen 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. RESULTS: Fourteen 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). CONCLUSION: Arthroscopic 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 EVIDENCE: IV.

Arthroscopic Anatomic Glenoid Reconstruction Using Distal Tibial Allograft for Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes.

BACKGROUND: The all-arthroscopic anatomic glenoid reconstruction technique using a distal tibial allograft avoids damage to the subscapularis muscle and allows repair of the capsulolabral tissue. PURPOSE: To analyze the clinicoradiologic outcomes of patients who underwent this procedure to treat anterior shoulder instability with glenoid bone loss with a minimum 2-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Over 6 years, 73 patients (52 male and 21 female; mean age, 28.8 years) under the care of the same surgeon underwent arthroscopic stabilization with capsulolabral Bankart repair and bony allograft augmentation of the glenoid for recurrent shoulder instability with significant bone loss. Pre- and postoperative patient-reported functional assessment was performed using 2 questionnaires, the Western Ontario Shoulder Instability Index (WOSI) and the Disabilities of the Arm, Shoulder and Hand, and radiological assessment was performed using radiographs and computed tomography scans obtained preoperatively and approximately 1 year later (mean ± SD, 0.9 ± 1.1 years). RESULTS: The mean follow-up was 4.7 ± 1.1 years. The mean pre- and postoperative WOSI scores were 71.1 ± 17.5 and 25.6 ± 21.9, respectively (P < .001). There were no recurrences of dislocation, although 1 patient had symptoms of subluxation; however, 5 patients had hardware complications that required screw removal. There were no cases of nerve injury. Postoperative computed tomography scans were available for 66 patients. Seven patients were lost to follow-up. The graft union rate was 100%. Overall, graft resorption was <50% in 86% of patients (57/66). Eighteen patients (27%) had no resorption (grade 0), 39 (59%) had <50% (grades 1 and 2), and 9 (14%) had ≥50% (grade 3); however, none had symptoms of instability. The mean alpha angle of the screw between the screw shaft axis and the native glenoid axis was 18.3°± 5.7°. Graft positioning was flush with the glenoid in 61 of 66 patients (92.4%), and vertical positioning was excellent in 64 of 66 patients (97.0%) (3- to 5-o'clock position). CONCLUSION: Arthroscopic stabilization using distal tibial allograft augmentation resulted in excellent clinicoradiologic outcomes at a 2-year follow-up. This procedure has the advantages of being an anatomic reconstruction that addresses bony and soft tissue instability. However, long-term follow-up studies are necessary for better assessment of outcomes.

Innovative Approaches in the Management of Shoulder Instability: Current Concept Review.

PURPOSE OF REVIEW: This article summarises the latest innovations and concepts in the management of shoulder instability associated with glenoid bone loss. RECENT FINDINGS: The management of shoulder instability has undergone significant evolution in the last century with rapid strides being made in the last few decades due to the transition from open to arthroscopic techniques allowing management of pathological entities which were previously untreatable. However, there is no consensus on treatment methods, especially in the presence of glenoid bone loss. The complication profile associated with non-anatomic glenoid bony reconstruction procedures has triggered research for alternate techniques using free bone grafts. Open Latarjet procedure continues to be the gold standard in the face of glenoid bone loss; however, arthroscopic anatomic glenoid reconstruction with bone block grafts is gaining in popularity and is associated with excellent short-term clinico-radiologic outcomes. Arthroscopic anatomic glenoid reconstruction using bone grafts has been proposed as an alternative to the complex all-arthroscopic Latarjet procedure with excellent short-term results, minimal complications and a relatively easier learning curve. Capsular reconstruction has emerged as option for the management of instability with poor quality or absent capsular tissue. Future long-term outcome studies and randomised comparative trials will determine if these innovations stand the test of time.

Arthroscopic Anatomic Glenoid Reconstruction: Analysis of the Learning Curve.

BACKGROUND: Anatomic glenoid reconstruction involves the use of distal tibial allograft for bony augmentation of the glenoid surface. An all-arthroscopic approach was recently described to avoid damage to the subscapularis tendon and preserve the capsule and labrum. PURPOSE: To explore and compare change in surgical time between 2 proposed methods used for the treatment of anterior shoulder instability-arthroscopic anatomic glenoid reconstruction (AAGR) and arthroscopic Latarjet (AL)-over successive procedures. We also compared graft positioning on the anterior glenoid surface between the 2 methods. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a single-surgeon retrospective review of 54 cases of surgically treated recurrent anterior shoulder instability: 27 had AAGR with distal tibial allograft, while the other 27 had AL. AAGR with the distal tibial allograft was the primary choice for the treatment of anterior shoulder instability; however, AL was performed when tibial allograft was not available from the bone bank. Thus, there was an overlapping period for those 2 procedures. Procedure start and end times were recorded, and duration was calculated. Postoperative 3-dimensional computed tomography scans were reviewed, and graft position was judged to be in the lower third (desired position), middle third, or upper third of the anterior glenoid surface. To assess learning, these data were organized in chronological order of surgery, and each surgical cohort was divided into 3 chronological clusters of 9 patients each. Learning was assessed through change in operative time over successive clusters, change in variability of operative time among clusters, and change in graft positioning among clusters. Statistical analysis comprised a 2-tailed independent-sample t test and the Levene test for equality of variance. RESULTS: Our study found that AAGR was significantly faster to perform than AL in the early (P = .001), middle (P = .001), and late (P = .05) clusters of each cohort. Duration of surgery did not significantly improve across clusters within each cohort (P = .15-.79). There were no significant changes in the variability of surgical time in the AAGR group (P = .09) or the AL group (P = .13). Desired positioning of the bone graft on the anterior glenoid surface (lower third) was identified more commonly in the AAGR cohort. CONCLUSION: AAGR is faster to learn and perform than AL for the treatment of recurrent anterior shoulder instability with significant glenoid bone loss. The current study found higher rates of desired graft positioning for AAGR clusters.

The Safety of a Far Medial Arthroscopic Portal for Anatomic Glenoid Reconstruction: A Cadaveric Study.

BACKGROUND: An arthroscopic technique for anatomic glenoid reconstruction has been proposed for the treatment of glenohumeral bone loss in patients with recurrent shoulder instability. This technique is proposed as an alternative to open techniques as well as to the technically challenging arthroscopic Latarjet procedure. In arthroscopic anatomic glenoid reconstruction, a distal tibial allograft is inserted through a novel far medial portal, superior to the subscapularis tendon and lateral to the conjoint tendon. PURPOSE: To evaluate the safety of the far medial arthroscopic portal for anatomic glenoid reconstruction in a cadaveric study. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten cadaveric shoulder specimens were dissected after inside-out medial arthroscopic portal insertion in the lateral decubitus position for arthroscopic anatomic glenoid reconstruction. A single observer performed 3 measurements on each specimen with a digital caliper (to the nearest 0.1 mm) from the medial portal to neurovascular structures, and the mean (±SD) and the range were calculated. The anthropometric data of the cadaveric specimens were also collected. RESULTS: The mean distances between the far medial arthroscopic portal and sensitive anatomic structures were as follows: 50.79 ± 13.69 mm from the musculocutaneous nerve, 46.28 ± 9.64 mm from the axillary nerve, 6.71 ± 8.52 mm from the cephalic vein, and 48.52 ± 7.22 mm from the subclavian artery and vein. The mean size of the medial arthroscopic portal was 25.60 mm. In all cases, the subscapularis muscle was intact. CONCLUSION: The far medial arthroscopic portal for anatomic glenoid reconstruction without a subscapularis split presents a minimal risk to most neurovascular structures during bony reconstruction of the glenoid surface in patients with anterior shoulder instability. The only anatomic structure at risk is the cephalic vein, while the axillary and musculocutaneous nerves are at a safe distance away from the portal, based on previous shoulder arthroscopic portal safety studies in the literature. CLINICAL RELEVANCE: Arthroscopic anatomic glenoid reconstruction using a distal tibial allograft is increasing in popularity for the treatment of anterior shoulder instability with significant bone loss. Being a relatively new technique, the safety of it has yet to be established. This study aimed to demonstrate the safety of a new portal used for arthroscopic anatomic glenoid reconstruction.