Outcomes of Arthroscopic Latarjet Procedure for Anterior Glenohumeral Instability in Patients With Epilepsy: A Case-Control Study

Background: Unacceptably high rates of redislocation, reoperation, osteoarthritis, and coracoid nonunion have been reported in patients with a seizure disorder after surgery for shoulder instabilitiy. Purpose: To evaluate the objective and subjective functional and radiologic results of the arthroscopic Latarjet procedure for anterior shoulder instability in patients with epilepsy and compare them with the results of patients without epilepsy. Study design: Cohort study; Level of evidence, 3. Methods: A retrospective and comparative case-control analysis of patients operated for shoulder instability with arthroscopic Latarjet was conducted. Nineteen patients (21 unstable shoulders) with a seizure disorder (epilepsy group) were matched with 21 patients without a history of seizure (control group). Demographics, surgical indications, and imaging data were collected. Clinical outcomes at a minimum 2 years of follow-up (range, 2-9 years) postoperatively included Rowe score, Western Ontario Shoulder Instability Index (WOSI), Constant-Murley Shoulder Outcome (CMSO) score, and Single Assessment Numeric Evaluation (SANE). The incidence of complications, recurrent instability, redislocation, revision surgery, repeated seizure(s), and presence of osteoarthritis, coracoid nonunion, and osteolysis were also examined. Results: After a mean follow-up of 4.5 years, no significant differences in functional results were found between patients with and without epilepsy on the average Rowe ( P = .917), WOSI ( P = .621), CMSO ( P = .600), and SANE ( P = .859) scores. A total of 5 patients (7 shoulders) continued to have seizures postoperatively, but no seizure-related glenohumeral instability was documented. One dislocation and 1 subluxation were documented while participating in sports in each study group, comprising a recurrence rate of 9.5%, but no significant differences were found at comparison ( P = .605). A bone defect did not influence the results, as no significant difference was found between the 2 groups. Osteoarthritic changes of the glenohumeral joint were observed in 5 shoulders (23.8%) in the epilepsy group and in 3 (14.3%) in the control group ( P = .451). No case of coracoid nonunion or osteolysis was recorded. There was no statistically significant difference in postoperative athletic activity ( P = .660). However, patients with epilepsy had significantly lower pre- and postoperative sports participation ( P < .001). Conclusion: Arthroscopic Latarjet stabilization can lead to improved functional and subjective outcomes and should be considered in patients with epilepsy with recurrent anterior glenohumeral instability. These results can be achieved regardless of the presence of bone defect and the postoperative control of seizures and are similar to those in patients without epilepsy.

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.

What Is the Most Reliable Method of Measuring Glenoid Bone Loss in Anterior Glenohumeral Instability? A Cadaveric Study Comparing Different Measurement Techniques for Glenoid Bone Loss

Background: Preoperative quantification of bone loss has a significant effect on surgical decision making and patient outcomes. Various measurement techniques for calculating glenoid bone loss have been proposed in the literature. To date, no studies have directly compared measurement techniques to determine which technique, if any, is the most reliable. Purpose/Hypothesis: To identify the most consistent and accurate techniques for measuring glenoid bone loss in anterior glenohumeral instability. Our hypothesis was that linear measurement techniques would have lower consistency and accuracy than surface area and statistical shape model–based measurement techniques. Study Design: Controlled laboratory study. Methods: In 6 fresh-frozen human shoulders, 3 incremental bone defects were sequentially created resulting in a total of 18 glenoid bone defect samples. Analysis was conducted using 2D and 3D computed tomography (CT) en face images. A total of 6 observers (3 experienced and 3 with less experience) measured the bone defect of all samples with Horos imaging software using 5 common methods. The methods included 2 linear techniques (Shaha, Griffith), 2 surface techniques (Barchilon, PICO), and 1 statistical shape model formula (Giles). Intraclass correlation (ICC) using a consistency model was used to determine consistency between observers for each of the measurement methods. Paired t tests were used to calculate the accuracy of each measurement technique relative to physical measurement. Results: For the more experienced observers, all methods indicated good consistency (ICC > 0.75; range, 0.75-0.88), except the Shaha method, which indicated moderate consistency (0.65 < ICC < 0.75; range, 0.65-0.74). Estimated consistency among the experienced observers was better for 2D than 3D images, although the differences were not significant (intervals contained 0). For less experienced observers, the Giles method in 2D had the highest estimated consistency (ICC, 0.88; 95% CI, 0.76-0.95), although Giles, Barchilon, Griffith, and PICO methods were not statistically different. Among less experienced observers, the 2D images using Barchilon and Giles methods had significantly higher consistency than the 3D images. Regarding accuracy, most of the methods statistically overestimated the actual physical measurements by a small amount (mean within 5%). The smallest bias was observed for the 2D Barchilon measurements, and the largest differences were observed for Giles and Griffith methods for both observer types. Conclusion: Glenoid bone loss calculation presents variability depending on the measurement technique, with different consistencies and accuracies. We recommend use of the Barchilon method by surgeons who frequently measure glenoid bone loss, because this method presents the best combined consistency and accuracy. However, for surgeons who measure glenoid bone loss occasionally, the most consistent method is the Giles method, although an adjustment for the overestimation bias may be required. Clinical Relevance: The Barchilon method for measuring bone loss has the best combined consistency and accuracy for surgeons who frequently measure bone loss.