Ilia Elkinson

Moderate to large engaging Hill-Sachs defects: an in vitro biomechanical comparison of the remplissage procedure, allograft humeral head reconstruction, and partial resurfacing arthroplasty

BACKGROUND The management of engaging Hill-Sachs defects (HSD) is controversial. The purpose of this study was to biomechanically compare 3 treatment strategies. MATERIALS AND METHODS Eight specimens were tested on a shoulder simulator. The protocol involved testing 2 unrepaired HSD (30% and 45%), which were then treated with remplissage, humeral head allograft (HHA), and partial resurfacing arthroplasty (PRA). Stability (defect engagement and glenohumeral stiffness) and range of motion (ROM) were measured. RESULTS All 30% and 45% HSDs engaged and dislocated. Remplissage and HHA effectively prevented engagement in all specimens; however, 62% of PRA engaged. No repair exhibited stiffness significantly greater than intact, but 30% and 45% remplissage produced a 74% and 207% increase, respectively, and were significantly greater than the unrepaired states (P ≤ .047). Stiffness results for HHA and PRA closely matched those of intact. In adduction, remplissage reduced internal-external ROM compared with both defects (P ≤ .01), but only 30% remplissage caused a significant decrease compared with intact (P = .049). In abduction, all repairs reduced ROM compared with HSD (P ≤ .04), but none compared with intact (P ≥ 0.05). In extension, remplissage had significantly less ROM than either HHA or PRA (P ≤ .02). CONCLUSION All procedures improved stability; however, unlike remplissage, results from HHA and PRA closely resembled intact. Remplissage (30% and 45%) improved stability and eliminated engagement but caused reductions in ROM. HHA and PRA re-established intact ROM, but PRA could not fully prevent engagement. The effects of each technique are not equivalent and further studies are required.

Does the dynamic sling effect of the Latarjet procedure improve shoulder stability? A biomechanical evaluation

INTRODUCTION Glenohumeral instability with glenoid bone loss is commonly treated with the Latarjet procedure. The procedure involves transfer of the coracoid and conjoint tendon, which is thought to provide a stabilizing sling effect; however, its significance is unknown. This study evaluated the effects of the Latarjet procedure, with and without conjoint tendon loading, on shoulder stability and range of motion (ROM). MATERIALS AND METHODS A custom simulator was used to evaluate anterior shoulder stability and ROM in 8 cadaveric shoulders. Testing conditions included intact, 30% glenoid defect, and Latarjet with and without conjoint loading. Unloaded and 10-N loaded states were tested in adduction and 90° abduction. Outcome variables included dislocation, stiffness (neutral and 60° external rotation), and internal-external rotational ROM. RESULTS All 30% defects dislocated in abduction external rotation. The loaded Latarjet prevented dislocation in all specimens, whereas the unloaded Latarjet stabilized 6 of 8 specimens. In abduction external rotation, there were no significant differences in stiffness between loaded and unloaded transfers (P = .176). In adduction, there were no significant differences between the intact and the loaded Latarjet (P ≥ .228); however, in neutral rotation, the unloaded Latarjet (P = .015) and the 30% defects (P = .011) were significantly less stiff. Rotational ROM in abduction was significantly reduced with the loaded Latarjet (P = .014) compared with unloaded Latarjet, and no differences were found in adduction. CONCLUSIONS These findings indicate that glenohumeral stability is improved, but not fully restored to intact, with conjoint tendon loading. The results support the existence of the sling effect and its importance in augmenting stability provided by the transferred coracoid.

The Effect of the Remplissage Procedure on Shoulder Stability and Range of Motion: An in Vitro Biomechanical Assessment

BACKGROUND The remplissage procedure may be performed as an adjunct to Bankart repair to treat recurrent glenohumeral dislocation associated with an engaging Hill-Sachs humeral head defect. The purpose of this in vitro biomechanical study was to examine the effects of the remplissage procedure on glenohumeral joint motion and stability. METHODS Cadaveric shoulders (n = 8) were mounted on a biomechanical testing apparatus that applies simulated loads to the rotator cuff and the anterior, middle, and posterior heads of the deltoid muscle. Testing was performed with the shoulder intact, after creation of the Bankart lesion, and after repair of the Bankart lesion. In addition, testing was performed after Bankart repair with and without remplissage in shoulders with 15% and 30% Hill-Sachs defects. Shoulder motion and glenohumeral translation were recorded with an optical tracking system. Outcomes measured included stability (joint stiffness and defect engagement) and internal-external glenohumeral rotational motion in adduction and in 90° of composite shoulder abduction. RESULTS In specimens with a 15% Hill-Sachs defect, Bankart repair combined with remplissage resulted in a significant reduction in internal-external range of motion in adduction (15.1° ± 11.1°, p = 0.039), but not in abduction (7.7° ± 9.9, p = 0.38), compared with the intact condition. In specimens with a 30% Hill-Sachs defect, repair that included remplissage also significantly reduced internal-external range of motion in adduction (14.5° ± 11.3°, p = 0.049) but not in abduction (6.2° ± 9.3°, p = 0.60). In specimens with a 15% Hill-Sachs defect, addition of remplissage significantly increased joint stiffness compared with isolated Bankart repair (p = 0.038), with the stiffness trending toward surpassing the level in the intact condition (p = 0.060). In specimens with a 30% Hill-Sachs defect, addition of remplissage restored joint stiffness to approximately normal (p = 0.41 compared with the intact condition). All of the specimens with a 30% Hill-Sachs defect engaged and dislocated after Bankart repair alone. The addition of remplissage was effective in preventing engagement and dislocation in all specimens. None of the specimens with a 15% Hill-Sachs defect engaged or dislocated after Bankart repair. CONCLUSIONS In this experimental model, addition of remplissage provided little additional benefit to a Bankart repair in specimens with a 15% Hill-Sachs defect, and it also reduced specific shoulder motions. However, Bankart repair alone was ineffective in preventing engagement and recurrent dislocation in specimens with a 30% Hill-Sachs defect. The addition of remplissage to the Bankart repair in these specimens prevented engagement and enhanced stability, although at the expense of some reduction in shoulder motion.

An anatomic, computed tomographic assessment of the coracoid process with special reference to the congruent-arc latarjet procedure.

PURPOSE The purpose of this study was to determine the dimensions of the coracoid and to compare the radius of curvature (ROC) of the intact glenoid to the ROC of the coracoid undersurface, as oriented in the congruent-arc Latarjet procedure. The ROC of the coracoid undersurface was also compared with various glenoid bone loss scenarios. METHODS Thirty-four computed tomography-based 3-dimensional models of the shoulder were examined by use of commercially available software. The mean dimensions of the coracoid were determined, and the ROC was calculated for the coracoid undersurface, the intact glenoid, and 20%, 35%, and 50% anterior glenoid bone loss scenarios. Intra-rater and inter-rater statistics were calculated. RESULTS The mean length, width, and thickness of the coracoid were 16.8 mm (SD, 2.5 mm), 15.0 mm (SD, 2.2 mm), and 10.5 mm (SD, 1.7 mm), respectively. The mean ROC values were 13.6 mm (SD, 3.4 mm) for the coracoid, 13.8 mm (SD, 2.1 mm) for the intact glenoid, 27.6 mm (SD, 5.3 mm) for 20% anterior glenoid bone loss, 30.5 mm (SD, 5.2 mm) for 35% bone loss, and 33.3 mm (SD, 5.2 mm) for 50% bone loss. The coracoid ROC was not significantly different from the intact glenoid (P = .75); however, it was significantly less (P < .01) when compared with all glenoid bone loss scenarios. Intra-rater reliability and inter-rater reliability were good or excellent. A coracoid oriented in the congruent-arc manner can reconstitute a significantly greater glenoid bone defect than a coracoid oriented in the classic manner (P < .001). CONCLUSIONS This image-based anatomic study found that the ROC of the coracoid undersurface matches the ROC of the intact anterior glenoid articular margin. In conditions with anterior glenoid bony deficiency, the radii of curvature differ significantly at the graft-native glenoid interface; however, the coracoid graft placed in the congruent-arc manner reconstitutes the ROC of the missing anterior glenoid rim. In addition, orienting the coracoid in the congruent-arc manner can reconstitute a greater glenoid bone defect than a coracoid placed in the original manner as described by Latarjet. CLINICAL RELEVANCE The congruent-arc Latarjet procedure, a modification of the original procedure, is truly congruent in relation to the intact anterior glenoid rim. In addition, the congruent-arc modification can reconstitute a greater glenoid bone defect when compared with the original Latarjet procedure.

Crista supinatoris fractures of the proximal part of the ulna.

BACKGROUND The crista supinatoris is the insertion site of the lateral collateral ligament complex on the proximal part of the ulna. The purpose of this study was to report the presentation, management, and outcomes of patients with crista supinatoris fractures. METHODS Twelve patients with fractures of the crista supinatoris were assessed clinically and radiographically and with validated outcomes at a mean of thirty-nine months after injury. Outcome measures included the Patient-Rated Elbow Evaluation (PREE), Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, American Shoulder and Elbow Surgeons elbow (ASES-e) score, and strength measured with a dynamometer. RESULTS No crista supinatoris fracture occurred in isolation. Other associated injuries included radial head fracture in ten patients (83%), a radial neck fracture in one patient, and a capitellar fracture in one. At the time of presentation, all crista factures were difficult to identify on standard radiographs, but oblique radiographs and/or computed tomography (CT) allowed definitive fracture identification. Four patients were managed nonoperatively, and eight patients were managed surgically, with the indication for surgery being the associated injuries, not specifically the presence of a crista fracture. At the time of surgery, posterolateral rotatory elbow instability, if present, was due to the crista fracture. At the time of follow-up, all elbows were clinically stable and had radiographic concentric reductions. Elbow flexion and extension were a mean (and standard deviation) of 136° ± 6° and 5° ± 8°, respectively. The mean PREE score was 15 ± 20, and the mean DASH was 13.5 ± 18. CONCLUSIONS Crista supinatoris fractures are difficult to identify on standard elbow radiographs. Fracture management is based on an assessment of elbow stability and on appropriate treatment of the associated injuries.

Crista Supinatoris Fractures of the Proximal Part of the Ulna: Surgical Technique

Overview Introduction Open reduction and internal fixation of crista supinatoris fractures is required when the elbow is unstable despite appropriate nonoperative management and when a patient is undergoing surgical treatment of a periarticular elbow fracture-dislocation. Step 1: Skin Incision and Surgical Approach Use a posterior or lateral skin incision according to your preference and then utilize the Kocher interval to access the joint, lateral collateral ligament, and crista supinatoris or, in the setting of a proximal ulnar fracture, use the Boyd interval. Step 2: Management of Associated Injuries Crista supinatoris fractures have not been identified in isolation; address associated injuries such as radial head/neck fractures, capitellar fractures, and coronoid fractures first. Step 3: Evaluation of Elbow Stability If elbow instability persists after the concomitant injuries have been addressed, fix the crista supinatoris. Step 4: Exposure of the Crista Supinatoris Expose the fracture fragment and base of the crista supinatoris. Step 5: Reduction and Fixation of the Crista Supinatoris Fracture Obtain an anatomic reduction and fixation of the crista supinatoris fracture to appropriately tension the lateral ulnar collateral ligament. Step 6: Reevaluation of Elbow Stability Gently evaluate the stability of the elbow following repair of the crista supinatoris fracture. Step 7: Postoperative Care Initiate rehabilitation on the basis of intraoperative stability and concomitant injuries. Results We recently conducted a retrospective review of the outcomes of twelve patients with a fracture of the crista supinatoris. Indications Contraindications Pitfalls & Challenges