Can Subscapularis Augmentation Serve as an Alternative to the Remplissage Procedure? A Case Report

Abstract

When performing surgical treatment for shoulder dislocation, the Remplissage procedure for large Hill-Sachs lesions, which correspond to off-track lesions, has been reported to yield satisfactory results using an arthroscopic approach. However, in cases of high-energy acute dislocation or acute-on-chronic dislocation, when the humeral head bony defect is too large, severe external rotation limitation may occur postoperatively, and if the bone quality is poor, there is a higher risk of anchor pull-out, leading to potential failure. To overcome these limitations, we opted to apply subscapularis augmentation instead, aiming to achieve satisfactory results. A 21-year-old male patient underwent subscapularis augmentation for a right shoulder dislocation accompanied by severe glenoid bone loss following seizures. Two years and three months later, he experienced another seizure episode without recurrence of right shoulder dislocation and showed satisfactory clinical outcomes. However, he developed a left shoulder dislocation. Therefore, we report a case of subscapularis augmentation as an alternative treatment for shoulder dislocation with significant glenoid bone loss. We aim to present a satisfactory outcome along with a literature review on this approach.

1. Introduction

Anterior shoulder dislocation frequently leads to recurring shoulder instability, particularly among younger individuals. Within the literature, recurring instability was observed in 50% to 96% of patients under the age of 20 who experienced primary dislocation and in 40% to 74% of individuals aged 20 to 40. This could necessitate surgical intervention due to compromised shoulder functionality and diminished quality of life [1,2]. Arthroscopic repair of the anterior labrum shows promising outcomes, with the failure rate after arthroscopic Bankart repair in patients without glenoid or humeral head defects decreasing to below 4%. However, in cases of considerable bone deficiency, the likelihood of recurrence can increase to 67% [3].

To stop the Hill-Sachs lesion from interacting with the glenoid rim, a technique called “Remplissage” employs the infraspinatus tendon and the posterior capsule to fill the defect, exemplifying one of the several approaches devised to manage humeral head bone loss [4].

However, in cases of severe humeral head bone defect, particularly in acute dislocation or acute on chronic lesions, and when bone quality is poor, anchors may be inserted into areas of bone injury, leading to occasional anchor failure or unsatisfactory fixation strength. This can consequently contribute to Remplissage failure [5].

In such cases, authors opted for subscapularis augmentation as an alternative approach, demonstrating satisfactory outcomes. We aim to report our findings after informed consent alongside a literature review.

2. Case

The patient, a 21-year-old male with no notable medical history, arrived at the emergency department after experiencing a seizure resulting in a right shoulder dislocation. Initial attempts at closed reduction by the emergency medicine specialist in the emergency room were unsuccessful. Magnetic resonance imaging revealed findings consistent with anterior inferior dislocation (Figure 1). Under the guidance of an orthopedic specialist, closed reduction using the traction-counter traction method was performed successfully. All apprehension relocation tests conducted during the physical examination were positive. The preoperative examination uncovered a large Hill-Sachs lesion associated with a Bankart lesion and an off-track lesion. In order to prevent recurrence of shoulder dislocation due to the off-track lesion, consideration was given to arthroscopic Remplissage and Bankart repair. However, because the large Hill-Sachs lesion restricted external rotation and to prevent anchor pullout at the acute fracture site, it was decided to implement subscapularis augmentation

3. Surgical Technique

Anesthesia was provided via an interscalene block, with the procedure performed in the lateral decubitus position. Following the application of three-point shoulder traction, posterior viewing and anterior working portals were utilized. Arthroscopic examination was performed (Arthrex, Naples, FL, USA), confirming the presence of a Bankart lesion and a large Hill-Sachs lesion (Figure 2). Upon probing the area of the Hill-Sachs lesion, an acute fracture pattern was observed, and poor bone quality was noted.

After preparing the glenoid using a burr, Bankart repair was performed using three Y-Knot^® Anchors (ConMed, New York, NY, USA). Subsequently, the shoulder was positioned in full external rotation, and subscapularis augmentation was carried out by performing labral repair together with the upper tendinous portion of the subscapularis using double-loaded Y-Knot^® All-Suture Anchors (Figure 3).

4. Postoperative Rehabilitation

After surgery, all patients used a shoulder abduction brace for 4 weeks. Pendulum exercises began 3 days post-surgery, followed by gradual initiation of passive joint exercises starting 1 week post-surgery. There were restrictions on forward elevation not exceeding 120 degrees and external rotation not exceeding 30 degrees until 4 weeks post-surgery. Assisted active joint exercises commenced at 4 weeks post-surgery, followed by active joint exercises at 6 weeks post-surgery, and resistive strengthening exercises at 8 weeks post-surgery. Progressive open and closed chain exercises were introduced to facilitate a gradual return to sports activities by 3 months post-surgery.

Through follow-up appointments with the neurology department, the patient initiated anticonvulsant treatment. One year post-surgery, the patient showed satisfactory outcomes, with no recurrence of seizures or shoulder dislocation. He achieved a Visual Analogue Scale score of 0 and an American Shoulder Elbow Score of 100. Apart from a 5-degree restriction in external rotation compared to the unaffected side, the patient demonstrated complete range of motion, suggesting a positive outcome.

However, 2 years and 3 months post-surgery, the patient experienced a recurrence of seizures and presented themselves to the outpatient clinic. The patient reported a seizure recurrence after this period and had recently experienced improvements in symptoms, leading them to discontinue anticonvulsant treatment. Interestingly, this time, the operated shoulder showed no symptoms, while the opposite shoulder, the left shoulder, experienced dislocation. Under the guidance of an orthopedic specialist, successful closed reduction was immediately performed. MRI findings revealed Bankart and large-sized Hill-Sachs lesions similar to those observed on the opposite side (Figure 4).

Using the same approach, arthroscopic Bankart repair and subscapularis augmentation were performed (Figure 5), followed by the same postoperative rehabilitation protocol. Referral to the neurology department was made again for anticonvulsant treatment. One year post-surgery, the patient showed satisfactory outcomes, with no recurrence of seizures or shoulder dislocation. He also achieved a Visual Analogue Scale score of 0 and an American Shoulder Elbow Score of 100. Apart from a 30-degree external rotation limitation, the patient demonstrated a full range of motion, indicating a satisfactory outcome.

5. Discussion

Individuals with epilepsy and various intricate seizure conditions regrettably endure multiple additional medical issues due to their seizures, one of which is shoulder instability [6].

In contrast to individuals without epilepsy, those with epilepsy demonstrate a notably elevated rate of shoulder dislocation recurrence after undergoing surgical treatment for instability. This heightened likelihood of recurrence could be linked to continued seizure activity following surgery or more pronounced pre-existing bone loss [7]. Addressing shoulder instability in patients with epilepsy necessitates a multidisciplinary strategy. The initial focus is on managing the seizure disorder to reduce the likelihood of further seizures. Given that surgical procedures can be stressful and potentially provoke seizures, it is essential to optimize medical treatment with anticonvulsant medications under the supervision of a neurology team. Poor adherence to anticonvulsants poses a considerable risk for recurrent seizures, underscoring the need for rigorous medication monitoring by all healthcare providers throughout the perioperative phase [8]. We also collaborated closely with our hospital’s neurology specialists to administer anticonvulsants aimed at reducing the risk of seizures during the surgical treatment.

In the United States, the most commonly performed surgical method for treating shoulder instability in patients without epilepsy is arthroscopic labral repair. This approach offers several advantages, including a quicker recovery time, improved visibility of intra-articular problems, and more favorable cosmetic outcomes. Factors contributing to the failure of a Bankart repair include insufficient anchor use, the frequency of dislocations prior to surgery, the time elapsed between the initial dislocation and surgery, off-track Hill-Sachs lesions, and the extent of accompanying glenoid bone loss [9]. Purchase and colleagues were the pioneers in describing the Remplissage procedure, which entails filling a Hill-Sachs lesion through infraspinatus tenodesis combined with posterior capsulodesis. This approach has gained prominence and is now frequently employed for off-track Hill-Sachs lesions [10].

In patients diagnosed with seizure disorders, a study investigated the outcomes of combining arthroscopic Bankart repair with Remplissage. This retrospective analysis involved 29 cases of recurrent anterior shoulder dislocations in individuals presenting with a Hill-Sachs defect, excluding those with greater than 20% glenoid bone loss. The average age of the group was 28.3 years, with an average follow-up duration of 3.1 years. The overall incidence of recurrent instability following surgery was 17.2% [11]. Crucially, patients who did not experience post-operative seizure activity did not encounter recurrent instability [11]. Thus, this study suggests that in patients with minimal bone loss and no post-operative seizure activity, the procedure is likely to be effective.

Nevertheless, in this instance, performing Remplissage was constrained by the risk of severe external rotation restriction when dealing with a large off-track Hill-Sachs lesion. As a result, subscapularis augmentation was chosen to mitigate the high risk of fixation failure due to anchor pullout in cases exhibiting an acute fracture pattern in the humeral head of the Hill-Sachs lesion.

Subscapularis augmentation has been reported to provide satisfactory results in preventing recurrent dislocations when applied in cases where anterior labral tissue is poor or there is glenoid bone loss. Studies have also reported that biomechanically, it can provide stability similar to the sling effect obtained from Latarjet procedures [12,13].

This procedure offers the advantage of omitting work in the posterior space, making it simpler and potentially reducing surgical time. It is considered as an alternative technique that can be used when there are concerns about fixation failure due to anchor pullout in areas of poor bone quality at the Hill-Sachs lesion site. In this case, arthroscopic Bankart repair and subscapularis augmentation were performed for the first right shoulder dislocation, and there was no recurrent dislocation in the right shoulder operated on during the second seizure, while the left shoulder, which was not operated on, experienced dislocation. Since this is a case report, it is difficult to attribute statistical significance to a single case. However, considering the numerous studies on the effectiveness of subscapularis augmentation, it is thought to be a safe alternative technique in cases where Remplissage is difficult to apply, such as the case presented in this paper, when integrating the results of the previous literature.