Anterior Glenoid Reconstruction With Distal Tibial Allograft: Biomechanical Impact of Fixation and Presence of a Retained Lateral Cortex

Background: Glenoid reconstruction with distal tibial allograft (DTA) is a known surgical option for treating recurrent glenohumeral instability with anterior glenoid bone loss; however, biomechanical analysis has yet to determine how graft variability and fixation options alter the torque of screw insertion and load to failure. Hypothesis: It was hypothesized that retention of the lateral cortex of the DTA graft and the presence of a washer with the screw will significantly increase the maximum screw placement torque as well as the load to failure. Study Design: Controlled laboratory study. Methods: Whole, fresh distal tibias were used to harvest 28 DTA grafts, half of which had the lateral cortex removed and half of which had the lateral cortex intact. The grafts were secured to polyurethane solid foam blocks with a 2-mm epoxy laminate to simulate a glenoid with an intact posterior glenoid cortex. Grafts underwent fixation with 4.0-mm cannulated drills, and screws and washers were used for half of each group of grafts while screws alone were used for the other half, creating 4 equal groups of 7 samples each. A digital torque-measuring screwdriver recorded peak torque for screw insertion. Constructs were then tested in compression with a uniaxial materials testing system and loaded in displacement control at 100 mm/min until at least 3 mm of displacement occurred. Ultimate load was defined as the load sustained at clinical failure. Results: The use of a washer significantly improved the ultimate torque that could be applied to the screws (+cortex and +washer = 12.42 N·m [SE, 0.82]; –cortex and +washer = 10.54 N·m [SE, 0.59]) ( P < .0001), whereas the presence of the native bone cortex did not have a significant effect (+cortex and –washer = 7.83 N·m [SE, 0.40]; –cortex and –washer = 8.03 N·m [SE, 0.56]) ( P = .181). Conclusion: In a hybrid construct of fresh cadaveric DTA grafts secured to a foam block glenoid model, the addition of washers was more effective than the retention of the lateral distal tibial cortex for both load to failure and peak torque during screw insertion. Clinical Relevance: This biomechanical study is relevant to the surgeon when choosing a graft and selecting fixation options during glenoid reconstruction with a DTA graft.

Instability and results after non-operative treatment of large anterior glenoid rim fractures: is there a correlation between fragment size or displacement and recurrence?

Introduction There is little data available on non-operative treatment of anterior glenoid rim fractures (GRF). Nothing is known about fracture size and displacement in comparison to clinical outcomes and instability in a mainly middle-aged patient population. The aim of this study was to demonstrate the results of non-operative treatment in anterior glenoid rim fractures with the special focus on potential instability/recurrence. Methods The inclusion criteria were non-operatively treated anterior GRF of at least ≥ 5 mm width using the age- and gender-matched Constant/Murley score (a.-/g.-CMS) and the Western Ontario Instability Index (WOSI). Radiographic parameters (fracture morphology, displacement, major tuberosity fractures and Hill–Sachs lesion using initial CT and radiographs) and the proportion of the fractured glenoid were detected (2D-CT-circle-method) and osteoarthritis (A.P. and axial radiographs) was classified according to Samilson/Prieto. Proportion of fractured glenoid and medial displacement were correlated with the recurrence rate and the clinical scores. Results N = 36 patients could be followed-up after a mean of 4.4 years [12–140 month, average age: 58 (± 13, 33–86) years]. The a.-/g.-CMS was 93 (± 11, 61–100) points, and the WOSI was 81% (± 22%, 35–100%) on average. The mean intraarticular displacement was 4 mm (± 3 mm; 0–14 mm). The 2D-circle-method showed a mean glenoid fracture involvement of 21% (± 11, 10–52%). Two cases of frozen shoulders and one case with biceps pathology were associated with the trauma. Within the followed-up patient group re-instability has occurred in n = 2 patients (6%) within the first two weeks after trauma. Osteoarthritis was found in n = 11 cases. There was no correlation between the scores and the fracture size/displacement [(a.-/g.-CMS vs. displacement: r = − 0.08; p = 0.6; vs. size: r = − 0.29; p = 0.2); (WOSI vs. displacement: r = − 0.14; p = 0.4; vs. size: r = − 0.37; p = 0.06)], but very large (≥ 21%) fractures with displacement ≥ 4 mm showed slightly worse results without significant difference (a.-/g.-CMS p = 0.2; WOSI p = 0.2). The apprehension test was negative in all patients at final follow-up. Conclusion Non-operative treatment of anterior GRF was associated with overall good results within a mainly middle-aged larger patient group. Re-instability is rare and is not associated with fragment size but can occur in the first weeks after trauma. Size and dislocation of the fracture is not a criterion for the prognosis of potential instability. Level of evidence Level IV, retrospective case series.

Arthroscopic Repair of the Bankart Lesion Using Dual-Row Labral Repair

Background: The most common technique described for bankart repair is the single-row labral repair. Recent interest has been the use of a dual-row, double pulley technique, first described by Zhang et al and popularized by Millett et al as the “bony Bankart bridge” technique. The aim of this study is to report a double-row all-suture labral fixation technique using knotless anchors. Technique: Step 1: glenohumeral debridement, and preparation of the glenoid labral and Bankart. The patient is first placed in the beach-chair position and surface landmarks are created. The standard posterior portal is first created and the glenohumeral joint is evaluated. Once the lesion is identified, the relevant working anterosuperior and anteroinferior portals are established using the outside-in technique. The synovitis is debrided to allow visualization and the labrum is liberated from the anterior glenoid. The Bankart lesion fragment is liberated, and partial fragments are osteotomized. With the anterolateral portal as the viewing portal, the anterior rim of the glenoid is now decorticated using a motorized shaver and rasp to create a bleeding bony surface. Step 2: the low rim anchor (5:30 o’clock). At the anterior-inferior aspect of the glenoid, the drill guide is positioned as low as possible (5:30 o’clock position for the right shoulder) and about 7 to 10 mm medial to the rim of the glenoid. The first 1.8 mm single-loaded suture anchor (Q-FIX All-Suture Anchor) is then inserted via the posterior portal. Step 3: the anterior-inferior-medial (AIM) anchor (4 o’clock). Step 4: the knotless high rim anchor (3 o’clock). Step 5: tying of sutures. The sutures from each anchor are tied in a mattress configuration, eventually creating a suture bridge over the labral repair Discussion/Conclusion: This dual row labral repair technique allows for maximum compression and contact between the fragment and the glenoid bed, allowing healing over a contact area rather than just the rim. The other added advantage is the use of curved tip anchors which allow negotiation of difficult corners, especially in the 5 to 6 o’clock position.

Evaluation of variations of the glenoid attachment of the inferior glenohumeral ligament by magnetic resonance arthrography

Objective: To evaluate the anatomical variations of the attachment of the inferior glenohumeral ligament (IGHL) to the anterior glenoid rim. Materials and Methods: This was a retrospective review of 93 magnetic resonance arthrography examinations of the shoulder. Two radiologists, who were blinded to the patient data and were working independently, read the examinations. Interobserver and intraobserver agreement were evaluated. The pattern of IGHL glenoid attachment and its position on the anterior glenoid rim were recorded. Results: In 50 examinations (53.8%), the glenoid attachment was classified as type I (originating from the labrum), whereas it was classified as type II (originating from the glenoid neck) in 43 (46.2%). The IGHL emerged at the 4 o’clock position in 58 cases (62.4%), at the 3 o’clock position in 14 (15.0%), and at the 5 o’clock position in 21 (22.6%). The rates of interobserver and intraobserver agreement were excellent. Conclusion: Although type I IGHL glenoid attachment is more common, we found a high prevalence of the type II variation. The IGHL emerged between the 3 o’clock and 5 o’clock positions, most commonly at the 4 o’clock position.

A review of bone grafting techniques for glenoid reconstruction

Background Traumatic anterior shoulder dislocations can cause bony defects of the anterior glenoid rim and are often associated with recurrent shoulder instability. For large glenoid defects of 20–30% without a mobile bony fragment, glenoid reconstruction with bone grafts is often recommended. This review describes two broad categories of glenoid reconstruction procedures found in literature: coracoid transfers involving the Bristow and Latarjet procedures, and free bone grafting techniques. Methods An electronic search of MEDLINE and PubMed was conducted to find original articles that described glenoid reconstruction techniques or modifications to existing techniques. Results Coracoid transfers involve the Bristow and Latarjet procedures. Modifications to these procedures such as arthroscopic execution, method of graft attachment and orientation have been described. Free bone grafts have been obtained from the iliac crest, distal tibia, acromion, distal clavicle and femoral condyle. Conclusion Both coracoid transfers and free bone grafting procedures are options for reconstructing large bony defects of the anterior glenoid rim and have had similar clinical outcomes. Free bone grafts may offer greater flexibility in graft shaping and choice of graft size depending on the bone stock chosen. Novel developments tend towards minimising invasiveness using arthroscopic approaches and examining alternative non-rigid graft fixation techniques.