MR Arthrogram Features That Can Be Used to Distinguish Between True Inferior Glenohumeral Ligament Complex Tears and Iatrogenic Extravasation.

OBJECTIVE: The purpose of this study is to identify features seen at shoulder MR arthrography that distinguish between iatrogenic contrast material extravasation and inferior glenohumeral ligament (IGHL) complex tears. MATERIALS AND METHODS: MR arthrograms (n = 1740) were screened for extravasation through the IGHL complex. Cases were defined on the basis of surgical findings or definitive lack of extravasation in a fully distended joint immediately after contrast agent injection. The location of the disruption and the morphologic features of the torn margin were assessed and compared between groups. RESULTS: Anterior band disruption was present in eight of 16 patients with true tears and in zero of 19 patients with iatrogenic contrast material extravasation (p < 0.001). Isolated extravasation through the posterior half of the axillary pouch was present in 12 patients with iatrogenic extravasation, compared with none of the patients with true tears (p < 0.001). Thick ends were present in 10 of the true tears, whereas none of the cases of iatrogenic extravasation showed this finding (p < 0.001). Scarred margins were seen in eight true tears and none of the iatrogenic extravasation cases (p < 0.001). The presence of a torn anterior band, thick ligament, reverse-tapered caliber, and scarred appearance of the torn margin were shown to be 100.0% specific, and a torn posterior band showed 84.2% specificity for true tears. The presence of isolated involvement of the posterior portion of axillary pouch showed 63.2% sensitivity and 100.0% specificity for iatrogenic extravasation. CONCLUSION: A torn anterior band, a thickened ligament (> 3 mm), reverse-tapered caliber, and scarred margin were 100.0% specific for a tear. Isolated disruption of the posterior axillary pouch was 100.0% specific for iatrogenic extravasation.

Glenohumeral translation during active external rotation with the shoulder abducted in cases with glenohumeral instability: a 4-dimensional computed tomography analysis.

BACKGROUND: Although glenohumeral instability is common, the mechanism of instability remains unclear. The purpose of this study was to quantitatively evaluate humeral head translation during active external rotation with abduction in patients with glenohumeral instability by use of 4-dimensional computed tomography scans. METHODS: Ten patients with unilateral glenohumeral instability with a positive fulcrum test were prospectively included in this study. Sequential computed tomography of bilateral shoulders during active external rotation at 90° of shoulder abduction was performed for 6 seconds at 5 frames per second. The 3-dimensional positions of the humeral head center in the anteroposterior, superoinferior, and mediolateral directions were calculated at 0°, 20°, 40°, 60°, and maximum shoulder abduction-external rotation from the starting position. Translation of the humeral head center from the starting position was evaluated using Dunnett multiple-comparison tests, and the differences between the affected and intact shoulders were assessed using Wilcoxon signed rank tests. RESULTS: The humeral head center translated posteriorly, inferiorly, and medially during glenohumeral external rotation with the shoulder in the abducted position on the intact side. However, the affected humeral head showed significantly less posterior translation (P = .028), greater inferior translation (P = .047), and less medial translation (P = .037) than the contralateral side. CONCLUSIONS: This study indicated that dysfunction of the anterior band of the inferior glenohumeral ligament causes decreased posterior, increased inferior, and decreased medial translation of the humeral head during active shoulder abduction-external rotation.

Effect of patient positioning in axillary nerve safety during arthroscopic inferior glenohumeral ligament plication.

PURPOSE: To evaluate the risk of injuring the axillary nerve during an inferior glenohumeral ligament (IGHL) plication and finding out whether shoulder position (either beach chair position or lateral decubitus position) has any effect in this risk. METHODS: The axillary nerve (AN) was identified through a 3-cm posterior incision in 12 cadaveric shoulders. Under arthroscopic visualization, a curved indirect suture-passing device was placed through the posterior and anterior bands of the IGHL. The distances between the device and the AN were measured with the shoulder specimen placed at simulated lateral decubitus position and beach chair position. RESULTS: There were no cases of nerve injury nor the suture-passing device came closer than 10 mm to the nerve. There was an increase in the injury risk to the AN when inserting the device at the posterior band of the IGHL in the beach chair position [median 13 mm (range 10-21 mm)] compared to the risk in the lateral decubitus position [22.5 mm (20-26 mm), significant differences, p < 0.001]. When the device was inserted at the anterior band of the IGHL, there were no significant differences (n.s.) [lateral decubitus position: 18 mm (14-24 mm) vs. 16 mm (13-18 mm)]. When comparing differences between bands, there were no differences in the beach chair position, but the risk was lower for the posterior band in the lateral decubitus position (p < 0.001). CONCLUSIONS: During plication of the posterior band of the IGHL, the risk is higher if the procedure is performed in the beach chair position. The posterior plication is safer than the anterior plication in lateral decubitus position. CLINICAL RELEVANCE: This study helps the surgeon to better understand the proximity of the nerve to the IGHL and to highlight that the risk of nerve injury during capsular plication might be reduced in the lateral decubitus position.

Inferior glenohumeral ligament (IGHL) complex: anatomy, injuries, imaging features, and treatment options.

The inferior glenohumeral ligament (IGHL) complex is comprised of three components supporting the inferior aspect of the shoulder. It consists of an anterior band, a posterior band, and an interposed axillary pouch. Injuries to the IGHL complex have a unifying clinical history of traumatic shoulder injury, which are often sports or fall-related, with the biomechanical mechanism, positioning of the arm, and individual patient factors determining the specific component of the ligamentous complex that is injured, the location of the injury of those components, and the degree of bone involvement. Several acronyms are employed to characterize these features, specifying whether there is involvement of a portion of the anterior band, posterior band, or midsubstance, and if there is avulsion from the humeral attachment, glenoid attachment, or both. Imaging recommendations for the evaluation of the IGHL complex include magnetic resonance imaging (MRI), and injuries to this complex are best visualized with magnetic resonance arthrography. Additionally, a brief description of clinical management of inferior glenohumeral ligament injuries is included.

Effect of Bankart repair on the loss of range of motion and the instability of the shoulder joint for recurrent anterior shoulder dislocation.

BACKGROUND: Bankart repair postoperative complications include loss of shoulder motion and shoulder instability. The primary reason that postoperative complications develop may be excessive imbrication of the anterior band of the inferior glenohumeral ligament (AIGHL) or inadequate repair position. The purpose of this study was to quantitatively evaluate the influence of inadequate repair by computer simulation for a normal shoulder joint. METHODS: Magnetic resonance images of 10 normal shoulder joints were acquired for 7 positions every 30° from the maximum internal rotation to the maximum external rotation with the arm abducted at 90°. The shortest 3-dimensional path of the AIGHL in each rotational orientation was calculated. We used computer simulations to anticipate the loss of motion and instability by changing the AIGHL length and insertion sites on the glenoid. RESULTS: The AIGHL length measured 50 ± 5 mm at the maximum external shoulder rotation. AIGHL shortening by 3, 6, and 9 mm made the angle of maximum external rotation 80°, 68°, and 54°, respectively. A superior deviation of 3, 6, and 9 mm on the glenoid insertion resulted in a maximum external rotation angle of 85°, 79°, and 77°. An inferior deviation of 3, 6, and 9 mm produced humeral head translation of 1.7, 2.9, and 3.6 mm. CONCLUSION: Simulation of both excessive imbrication and deviation of the insertion position led to quantitative prediction of the resulting loss of motion and instability. These findings will be useful for anticipating complications after Bankart repair. LEVEL OF EVIDENCE: Basic science study, computer modeling, imaging.

Serial Magnetic Resonance Arthrography for a Midsubstance Capsular Tear in a Patient With Traumatic Anterior Shoulder Instability.

The natural history of midsubstance capsular tears (MCTs) is unclear. We herein describe a case of MCT observed using serial magnetic resonance (MR) arthrography. A 46-year-old woman presented with excessive external rotation of the left glenohumeral joint, resulting in an initial anterior dislocation of the left shoulder. She subsequently developed recurrent shoulder joint dislocations. MR arthrography revealed an MCT without a Bankart lesion three months after the initial dislocation. She opted for nonoperative treatment, but the shoulder instability did not improve. The second MR arthrography, nine months after the initial dislocation, showed no natural healing of the MCT. The third MR arthrography, 12 months after the initial dislocation, also showed no natural healing. Her shoulder instability remained persistent. The patient then decided to have surgery. Arthroscopy revealed a large capsular defect extending from the glenoid to the humeral head in the anterior inferior glenohumeral ligamentous complex. The MCT was repaired with the placement of nonabsorbable sutures in a side-to-side fashion. At the final follow-up, three years postoperatively, the patient had no anterior shoulder instability. The Rowe score was 100 points. MR arthrography showed good repair integrity of the MCT at one year postoperatively. Serial MR arthrography was useful for both the patient and the shoulder surgeon in considering the treatment of the MCT, facilitating an accurate and qualitative assessment of whether natural healing of the MCT had been achieved.

Effect of glenohumeral ligaments on posterior shoulder stabilization: a biomechanical study.

OBJECTIVES: To theoretically confirm that the glenohumeral ligament (GHL), specifically the inferior glenohumeral ligament (IGHL), plays an important role in posterior shoulder stability in different postures, and to provide reference for clinical diagnosis and treatment of posterior shoulder instability (PSI). MATERIALS AND METHODS: In this retrospective study, bone-ligament-bone models were established in 15 fresh adult shoulder joint specimens and selective cutting was performed for analysis. The humeral head was loaded posteriorly at a central pressure of 22N using the INSTRON8874 biomechanical testing system and the load-displacement curve was plotted. The posterior displacement of the humeral head was measured after continuous cutting of the following structures: (1) complete; (2) superior glenohumeral ligament (SGHL); (3) SGHL + middle glenohumeral ligament (MGHL); (4) SGHL + MGHL + IGHL; (5) MGHL; (6) MGHL + IGHL; (7) anterior-bundle IGHL (IGHL-AB); (8) posterior-bundle IGHL (IGHL-PB); (9) IGHL. The results obtained were analyzed using the SPSS10.0 statistical software. RESULTS: Favorable posterior stability of the complete bone-ligament-bone model was observed, with an average displacement of 11.32±3.89 mm. The displacement of SGHL and SGHL + MGHL groups was not significantly increased compared with that in the complete group (P>0.05). After cutting of SGHL + MGHL + IGHL, the posterior displacement of all angles increased (P<0.05), resulting in PSI that was manifested in dislocation or subluxation. There was no obvious increase in posterior displacement after cutting the IGHL-AB (P>0.05). Significantly increased posterior displacement was observed at 45° abduction after cutting the IGHL-PB compared with the complete group, but not at the 90° abduction. The posterior displacement increased obviously at both 45° and 90° abduction when the IGHL was completely cut off (P<0.05). CONCLUSIONS: Repairing the IGHL plays a certain role in rebuilding the posterior stability of the shoulder joint. Detecting the function of the IGHL in the abduction and external rotation positions of the shoulder joint has certain significance for diagnosing PSI.

The biomechanical effect of injury and repair of the inferior glenohumeral ligament on glenohumeral stability: Contribution of the posterior band.

BACKGROUND: Many surgical procedures are proposed to manage shoulder instability with recurrent dislocation but there is still a high rate of failure or complications. Repairs are often limited to anterior part of inferior glenohumeral ligament but some authors are reporting better clinical results if its posterior band is also repaired. This biomechanical study aimed to investigate the impact of a supplementary posterior injury compared with an isolated anterior injury and to analyze the contribution of a posterior repair of the inferior glenohumeral ligament compared with an isolated anterior repair. METHODS: Six fresh-frozen cadaveric shoulders were tested intact and after both anterior and posterior injuries and repairs of the inferior glenohumeral ligament. Shoulders were placed at 90° of humerothoracic elevation in scapular plane and 60° of external rotation. Joint stability was analyzed by successively applying anterior, posterior, inferior and superior glenohumeral displacements and measuring the resulting forces or by applying an anteroinferior loading and measuring three-dimensional head displacements. Maximal range of external rotation was also measured. FINDINGS: Combined anterior and posterior injuries of the inferior glenohumeral ligament were necessary to obtain significant instabilities in anterior and inferior directions. A complementary repair of the posterior band improved the biomechanical stability of the glenohumeral joint compared to an isolated anterior repair when anterior and posterior bands are injured. No reduction of external rotation was observed after repairs compared to intact condition. INTERPRETATION: These results show the biomechanical interest of this surgical procedure and contribute to document its relevance in clinical practice.

Mapping of the Inferior Glenohumeral Ligament for Suture Pullout Strength: A Biomechanical Analysis.

BACKGROUND: Suture pullout during rehabilitation may result in loss of tension in the inferior glenohumeral ligament (IGHL) and contribute to recurrent instability after capsular plication, performed with or without labral repair. To date, the suture pullout strength in the IGHL is not well-documented. This may contribute to recurrent instability. PURPOSE/HYPOTHESIS: A cadaveric biomechanical study was designed to investigate the suture pullout strength of sutures in the IGHL. We hypothesized that there would be no significant variability of suture pullout strength between specimens and zones. Additionally, we sought to determine the impact of early mobilization on sutures in the IGHL at time zero. We hypothesized that capsular plication sutures would fail under low load. STUDY DESIGN: Descriptive laboratory study. METHODS: Seven fresh-frozen cadaveric shoulders were dissected to isolate the IGHL complex, which was then divided into 18 zones. Sutures in these zones were attached to a linear actuator, and the resistance to suture pullout was recorded. A suture pullout strength map of the IGHL was constructed. These loads were used to calculate the load applied at the hand that would initiate suture pullout in the IGHL. RESULTS: Mean suture pullout strength for all specimens was 61.6 ± 26.1 N. The maximum load found to cause suture pullout through tissue was found to be low, regardless of zone of the IGHL. Calculations suggest that an external rotation force applied to the hand of only 9.6 N may be sufficient to tear capsular sutures at time zero. CONCLUSION: This study did not provide clear evidence of desirable locations for fixation in the IGHL. However, given the low magnitude of failure loads, the results suggest the timetable for initiation of range-of-motion exercises should be reconsidered to prevent suture pullout through the IGHL. CLINICAL RELEVANCE: From this biomechanical study, the magnitude of force required to cause suture pullout through the IGHL is met or surpassed by normal postoperative early range-of-motion protocols.

Hybrid suture technique vs simple suture technique for antero-inferior labral tears: Two years' clinical outcomes.

BACKGROUND: We previously reported a hybrid suture technique, wherein mattress and simple suturing are used to create Mason-Allen configuration, with low recurrence rates. This comparative study looking at the two years' clinical outcomes of arthroscopic anterior labral repair using the hybrid suture technique versus simple suture technique. METHODS: We identified 103 patients who underwent arthroscopic anterior labral repair from 2010 to 2015 with 2-year follow-up. The patients were categorized into two groups: hybrid suture technique (65 patients) and simple suture technique (38 patients). Clinical outcomes measures included UCLA shoulder score, Constant Shoulder Score, Numerical Pain Rating Scale, and Oxford Instability score. RESULTS: Mean age of the patients was 27.02 ±â€¯9.76 years (17-63), with 91 males and 12 females. At 24 months, both groups showed significant improvement in post-operative clinical scores compared to pre-operation. The patients in hybrid sutures technique demonstrated significant improvement in Constant Shoulder Score, UCLA shoulder score and Oxford Instability score compared to simple suture group at 3 months follow up. (121.98 ±â€¯21.05 vs 109.32 ±â€¯21.15, p < 0.05; 65.5 ±â€¯19 vs 57.4 ±â€¯17.6, p < 0.05; 27.3 ±â€¯5.7 vs 23.7 ±â€¯5.0, p < 0.05; 29.3 ±â€¯8.9 vs 33.4 ±â€¯8.2, p < 0.05). The postoperative recurrence rate was comparable between both groups (hybrid suture group 7.81% vs simple suture group 7.84%). CONCLUSIONS: Arthroscopic anterior labral repair with hybrid suture technique offers significant early improvements in clinical scores and low recurrence rate compared to simple suture technique at 2-year follow-up. LEVEL OF EVIDENCE: Level III; Retrospective Cohort Design; Treatment study.

Axillary Nerve Position in Humeral Avulsions of the Glenohumeral Ligament.

BACKGROUND: The axillary nerve is at risk during repair of a humeral avulsion of the glenohumeral ligament (HAGL). PURPOSE: To measure the distance between the axillary nerve and the free edge of a HAGL lesion on preoperative magnetic resonance imaging (MRI) and compare these findings to the actual intraoperative distance measured during open HAGL repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 25 patients with anterior instability were diagnosed as having a HAGL lesion on MRI and proceeded to open repair. The proximity of the axillary nerve to the free edge of the HAGL lesion was measured intraoperatively at the 6-o'clock position relative to the glenoid face. Preoperative MRI was then used to measure the distance between the axillary nerve and the free edge of the HAGL lesion at the same position. Distances were compared using paired t tests and Bland-Altman analyses. RESULTS: The axillary nerve lay, on average, 5.60 ± 2.51 mm from the free edge of the HAGL lesion at the 6-o'clock position on preoperative MRI, while the mean actual intraoperative distance during open HAGL repair was 4.84 ± 2.56 mm, although this difference was not significant (P = .154). In 52% (13/25) of patients, the actual intraoperative distance of the axillary nerve to the free edge of the HAGL lesion was overestimated by preoperative MRI. In 36% (9/25), this overestimation of distance was greater than 2 mm. CONCLUSION: The observed overestimations, although not significant in this study, suggest a smaller safety margin than might be expected and hence a substantially higher risk for potential damage. We recommend that shoulder surgeons exercise caution in placing capsular sutures in the lateral edge when contemplating arthroscopic repair of HAGL lesions, as the proximity of the nerve to the free edge of the HAGL tear is small enough to be injured by arthroscopic suture-passing instruments.

Arthroscopic autograft reconstruction of the inferior glenohumeral ligament: Exploration of technical feasibility in cadaveric shoulder specimens.

Failure of primary arthroscopic Bankart repair in anterior-inferior glenohumeral instability is low, but in some cases revision surgery is required. Revision procedures show good to excellent results but typically are done open and do not respect the anatomical functionality of the joint capsule. The purpose of this cadaveric study was to explore the feasibility of a completely arthroscopic anatomical reconstruction of the inferior glenohumeral ligament using a hamstring autograft.

Is protecting the healing ligament beneficial after immobilization in external rotation for an initial shoulder dislocation?

BACKGROUND: Immobilization in external rotation is one of the treatment options for an initial dislocation of the shoulder. However, it remains unclear how long it takes for a Bankart lesion to heal. HYPOTHESIS: Protection of a healing Bankart lesion from stretching would promote the healing process and decrease the recurrence rate after an initial dislocation of the shoulder. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: This was a multicenter, prospective randomized study. Between January 2005 and August 2009, 109 patients (71 male and 38 female; mean age, 30 years) with an initial traumatic dislocation of the shoulder were enrolled. After 3 weeks of immobilization in external rotation, a shoulder motion restriction band designed to avoid stretching the anteroinferior shoulder capsule was used for 0 weeks (36 patients), 3 weeks (37 patients), or 6 weeks (36 patients). After using the band, patients were allowed to use their shoulders freely, but they were advised to avoid vigorous sport activities for at least 3 months after the injury. Any recurrent dislocation and return to sports were assessed at 2-year follow-up. RESULTS: Of 109 patients, 90 were followed up for 2 years. The compliance rates were 60% to 72% among the groups (P = .54). The recurrence rate of dislocation was 28% in the 0-week group, 33% in the 3-week group, and 32% in the 6-week group (P = .88) according to the intention-to-treat analysis, and they were a respective 24%, 28%, and 27% according to the per-protocol analysis (P = .95). Based on the sport activity level, the recurrence rates for patients involved in contact sports (7/15, 47%) and those involved in noncontact sports (19/51, 37%) were significantly higher than for those not involved in sport activities (2/24, 8.3%) (P = .0076). Among the 3 groups, there were no significant differences in the recurrence rates. There was no significant difference in the rate of return to sports (P = .39). CONCLUSION: No difference in the recurrence rate was seen with the use of a shoulder motion restriction band after 3 weeks of immobilization in external rotation after an initial dislocation of the shoulder.