Introduction Shoulder pain and glenohumeral instability can be the result of a wide range of pathologies, including humeral avulsion of the glenohumeral ligament (HAGL). The glenohumeral ligament functions to passively stabilize the shoulder joint (1). HAGL lesions, historically, have been described as most commonly occurring at the anterior glenohumeral ligament leading to anterior instability (2,3). Posterior humeral avulsion of the glenohumeral ligament (PHAGL) lesions is rare and can lead to posterior instability. There have only been a few case reports published that described PHAGL lesions (4–6). These tears are often associated with labral tears with some reports of concomitant rotator cuff tears (4,7–9). The diagnosis of PHAGL lesions can be exceedingly difficult secondary to the lack of specific findings, as well as the various mechanisms that can cause injuries to this region (4). The purpose of this case report is to describe a PHAGL lesion that presented as chronic shoulder pain with successful diagnosis and repair, demonstrating the nonspecific nature by which this injury can present. Case Report A 17-year-old right-handed female softball pitcher with no significant medical history presented to the clinic with several months of right shoulder pain after sliding headfirst into a base. She described the pain as sudden in onset, 3/10 in severity, intermittently aching, and throbbing over the anterior shoulder and trapezius. Pain was aggravated by reaching, lifting, pulling, pushing, and throwing, thus limiting her ability to perform these activities. Ibuprofen slightly diminished the pain though not overly effective. She endorsed mild stiffness of her shoulder, but denied any weakness, crepitus, or swelling. Physical examination of the right arm was notable for right shoulder tenderness over the acromion and biceps tendon; no swelling; positive speed, anterior apprehension, Hawkins, and impingement tests; limited functional range of motion (active abduction, 110°; passive abduction, 140°; external rotation, 90°; forward flexion, 170°), and limited muscle strength (abduction, 4/5; internal rotation, 5/5; external rotation, 4/5; supraspinatus, 4/5; subscapularis, 5/5; and biceps, 4/5). Relocation, cross arm, drop arm, load shift, and jerk tests were negative. Sulcus was absent, and O'Brien was equivocal. Sensation was intact throughout the arm and radial pulses were 2+ bilaterally. Left shoulder physical examination was without deficits or abnormalities, including a negative sulcus sign. History and physical examination were consistent with an anterior to posterior tear of the superior glenoid labrum (SLAP lesion) of the right shoulder with potential biceps pathology and conservative treatment with rest, physical therapy to strengthen rotator cuffs, and naproxen twice a day was pursued. One month later, the patient returned with continued pain of her right shoulder. A gadolinium contrast magnetic resonance imaging (MRI) arthrogram of her right shoulder was subsequently performed and showed a PHAGL tear of the inferior glenohumeral ligament (IGHL) with no evidence of a SLAP tear, other labral detachment, or muscle pathology. Surgical referral was made due to failed conservative treatment and ultimately the decision was made to undergo arthroscopic repair. Arthroscopic surgical exploration of the region revealed type 2 SLAP tear, nondisplaced posterior labral tear, subacromial bursitis, and a large right shoulder PHAGL lesion (Figs. 1 and 2) without a Bankart lesion. Loose frayed cartilage and tissue of the PHAGL lesion and of the inferior anterior aspect of the humerus were debrided with a shaver. A bleeding bony bed was created to facilitate healing at the repair site. The anterior and posterior aspects of the HAGL lesion were sutured, repairing the defect (Fig. 3) and restoring proper tension on the anterior and posterior bands of the IGHL (Fig. 4). The frayed ends of the PHAGL lesion were debrided, and the two ends were reattached. A SLAP repair was then performed along with subacromial decompression and synovectomy.Figure 1: MRI coronal view of PHAGL.Figure 2: MRI axial view of PHAGL.Figure 3: Arthroscopic evaluation of PHAGL.Figure 4: Arthroscopic repair of PHAGL.At 2 wk postoperatively, the patient was doing well with her pain under control. She is nonweight bearing with a sling to her right upper extremity for 6 to 8 wk and is participating in physical therapy after an HAGL repair protocol. Per protocol, she will work on early passive range of motion for 6 wk with forward flexion limited to less than 120°, abduction to less than 90°, and external rotation to less than 30°. After 6 wk, she will progress to full passive range of motion. Assisted range of motion and active range of motion will begin at week 8, at which point, she will be weaned from the sling. At 12 wk, she will begin a strengthening program, and at 5 to 6 months, she can begin an interval throwing program, depending on the pain tolerance. Discussion The shoulder consists of a superior, middle, and IGHL that function to passively stabilize the shoulder. The glenohumeral ligaments can fail at the glenoid insertion, the ligament substance, or the humeral insertion. A study by Bigliani et al. (10) found that failure at the humeral insertion (HAGL lesions) of the IGHL were found to be less common (25%) as compared with glenoid insertion failure (40%) and ligament substance failure (35%). HAGL lesions most commonly occur anteriorly, and PHAGL lesions are exceedingly rare, accounting for about 7% of all HAGL lesions (2,3). PHAGL lesions can be a cause of shoulder pain, discomfort, and posterior instability (4–6,11). Previous studies have associated PHAGL lesions with posterior instability (5,6); however, a more recent study by Castagna et al. (4) also associated this lesion with anterior instability. In their study, they looked at nine patients with PHAGL lesions and found that in six (67%) of the nine patients, there were other intra-articular shoulder abnormalities (SLAP lesion, Bankart lesion, anterior labroligamentous periosteal sleeve avulsion), and in only three (33%) of the nine patients, there was an isolated PHAGL lesion. In this case report, we examined a case of a female softball player who presented with chronic shoulder pain secondary to a PHAGL lesion of the IGHL with a concomitant SLAP tear. The IGHL is split into anterior and posterior portions. In neutral positions, the IGHL has negligible tension on it; however, the resistance, and thus tension, of this ligament increases between 45° and 90° of abduction and with external rotation (1,9,12). The anterior and posterior portions of the IGHL limit external and internal rotations, respectively, and both together stabilize against anteroinferior shoulder dislocation (4,12). Damage to the IGHL can, therefore, lead to anterior and inferior shoulder instability. As seen in the case, recognition and diagnosis of a PHAGL lesion is very difficult and often requires a very high index of clinical suspicion because of the lack of specific symptoms. Additionally, diagnosis of this lesion is made even more difficult because of the frequent concurrence of other shoulder intra-articular or muscular abnormalities. Patients with PHAGL lesions should have both the anterior and posterior stabilities of their shoulder tested. Additionally, shoulder pain with forward flexion and internal rotation should increase suspicion of a PHAGL lesion (4,5). Contrast-enhanced MRI of the shoulder is a useful tool in both diagnosing and planning surgical treatment of PHAGL lesions. Without 100% sensitivity, MRI may not reveal PHAGL lesions, thus visualizing the lesion through arthroscopy of the shoulder joint is the most consistent method of confirmed diagnosis (4,6,13). Conclusions PHAGL lesions are rare and often diagnostically challenging. They have very nonspecific findings that can often be further complicated by other concomitant shoulder pathologies. Diagnosis of these lesions cannot be made solely by history and physical examination. To properly diagnose PHAGL lesions, one must have a high clinical suspicion for the lesion as well as perform a contrast enhanced MRI and/or arthroscopic examination of the shoulder joint to visualize the lesion. Patient Consent The patient provided informed consent.
Search from 250 M+ research papersSearch from 250 M+ research papers
Open Access
Mar 1, 2024
Clare K Green + 5