Anchorless Onlay Dynamic Anterior Stabilization of the Shoulder Using a Guided Posterior Double Endobutton Fixation.

The treatment of shoulder instability in the presence of a subcritical glenoid defect poses challenges, as simple Bankart seems insufficient, and the Latarjet procedure may be excessive. Recently, a dynamic anterior stabilization technique involving anterior transposition of the long head of the biceps (LHB) through a subscapularis split was described for that purpose. Previously published results demonstrated good short-term results, but several technical pitfalls have also been mentioned. We describe an onlay, anchorless, and intra-articular knotless method of fixing the LHB into the anterior glenoid that provides the important stabilizing "sling effect" of the dynamic anterior stabilization while avoiding some of the pitfalls described by other techniques.

Combined Vertical, Horizontal, and Rotational Acromioclavicular Joint Stabilization: "Closing the Circle" Technique.

The biomechanical and anatomical complexity of the acromioclavicular joint makes its repair techniques particularly challenging. High rates of reduction subsidence and construction failures transversally affect both anatomic and nonanatomic repair techniques. The importance of addressing both vertical and horizontal instability has been highlighted in recent years. The authors aim to describe a surgical technique that combines vertical, horizontal, and rotational stabilization, in an attempt to restore the coracoacromioclavicular circle of stability.

Mechanical consequences at the tendon-bone interface of different medial row knotless configurations and lateral row tension in a simulated rotator cuff repair.

PURPOSE: Little is known about the direct influence of different technical options at the rotator cuff tendon-bone interface (TBI) and, more specifically, at the medial bearing row (MBR), regarding local contact force, area and pressure. We evaluated the mechanical repercussions of different medial row anchor configurations for that setting using different values of tension in the lateral row anchors. METHODS: Knotless transosseous equivalent (TOE) rotator cuff repairs with locked versus nonlocked medial anchors and single versus double-hole suture passage were tested in a synthetic rotator cuff mechanical model, using 2 different values of lateral row tension. Contact force, area, pressure, peak force and MBR force were compared at the simulated TBI using a pressure mapping sensor. RESULTS: When compared to locked anchors, medial row sliding configurations generate lower values for all the above-mentioned parameters. The use of double-hole suture passage in the medial cuff generated slightly higher values contact area regardless of lateral row tension. At higher lateral row tension values, lower values of the remaining parameters, including MBR force, were found when compared to single-hole suture passage. Lateral row anchor tension increase induced an increase of all parameters regardless of the medial row configuration and TBI contact force and MBR force were the most susceptible parameters, regardless of the medial row pattern. CONCLUSION: Medial row mechanism, suture configuration and lateral row tension interfere with the mechanical force, area and pressure at by TBI. Lateral row tension increase is a major influencer in those parameters. These results can help surgeons choose the right technique considering its mechanical effect at the TBI.

Arthroscopic Anatomical Acromioclavicular Joint Reconstruction using a Button Device and a Semitendinosus Graft.

OBJECTIVE: To report a new technique for anatomical acromioclavicular (AC) joint reconstruction. METHODS: In order to minimize such complications, the authors describe a new anatomical and biological AC joint repair. This technique aims to provide greater stability by using two anatomically placed clavicular tunnels and a combined construct with a double endobutton cortical fixation for primary stabilization, and to be biologically advantageous by using an autologous semitendinosus (ST) tendon graft. Additionally, the coracoclavicular ligament reconstruction is complemented with an AC joint cerclage and capsular reinforcement, which will protect the biological construction in its initial stage of healing. RESULTS: This technique provides adequate primary and secondary biomechanical stability by passing both a semitendinosus autogenous graft and a double endobutton device, through anatomically placed and small diameter clavicle holes, without the need for coracoid drilling. Our technique showed encouraging results regarding pain resolution, range of motion, and function. At final follow-up we experienced excellent results with average pain score of 1.6, and average ROM of 159° of forward flexion, 160° of abduction, 68° of external rotation, and internal rotation level at T11. Postoperative function also showed great improvements with average ASES of 85 points, an average Constant Score of 87 and a Subjective Shoulder Value of 89 points. This technique also achieved perfectly acceptable radiographic results, with an average coracoclavicular distance increase of 0.8 mm. Regarding complications, our sample showed one case of AC join subluxation, two cases of internal saphenous nerve injury, and two partial graft tears at the suture-button interface, with none of these requiring surgical revision. CONCLUSION: This technique is advantageous in treatment of acromioclavicular joint dislocation and can be performed in both the subacute and chronic setting.

A Technique for a More Accurate Acromioclavicular Joint Reduction in Arthroscopic Coracoclavicular Stabilization of Acromioclavicular Joint Dislocation.

Loss of reduction is the most common complication following acromioclavicular dislocations treatment, with literature showing greater postoperative coracoclavicular distances associated with worse clinical results. We present a surgical gesture that aims to help surgeons achieve and secure an anatomic acromioclavicular reduction during coracoclavicular fixation. This technique has the possibility to improve radiological and functional results of acromioclavicular dislocation treatment.

Why are tapes better than wires in knotless rotator cuff repairs? An evaluation of force, pressure and contact area in a tendon bone unit mechanical model.

PURPOSE: Knotless repairs have demonstrated encouraging performance regarding retear rate reduction, but literature aiming at identifying the specific variables responsible for these results is scarce and conflictive. The purpose of this paper was to evaluate the effect of the material (tape or wire suture) and medial tendon passage (single or double passage) on the contact force, pressure and area at the tendon bone interface in order to identify the key factors responsible for this repairs´ success. METHODS: A specific knotless transosseous equivalent cuff repair was simulated using 2 tape or suture wire loaded medial anchors and 2 lateral anchors, with controlled lateral suture limb tension. The repair was performed in a previously validated sawbones® mechanical model. Testing analyzed force, pressure and area in a predetermined and constant size "repair box" using a Tekscan® sensor, as well as peak force and pressure, force applied by specific sutures and force variation along the repair box. RESULTS: Tapes generate lower contact force and pressure and double medial passage at the medial tendon is associated with higher contact area. Suture wires generate higher peak force and pressure on the repair and higher mean force in their tendon path and at the medial bearing row. Force values decrease from medial to lateral and from posterior to anterior independently of the material or medial passage. CONCLUSION: Contrary to most biomechanical literature, suture tape use lowers the pressure and force applied at the tendon bone junction, while higher number of suture passage points medially increases the area of contact. These findings may explain the superior clinical results obtained with the use uf suture tapes because its smaller compressive effect over the tendon may create a better perfusion environment healing while maintaining adequate biomechanical stability.