Pseudoaneurysm-Induced Pain Following Ankle Arthroscopy: A Case Report and Literature Review

Introduction

After arthroscopic surgery, a range of complications arise in approximately 1–24.6% of cases, with neurological complications known to occur in 0.5–11.5% [1–4]. Other potential complications include infection, wound-related complication, deep vein thrombosis (DVT), and tendon injuries [4]. Pseudoaneurysm following arthroscopic surgery is a rare complication [5,6]. A pseudoaneurysm is a vascular abnormality where blood leaks out of an artery and is contained by surrounding tissues, forming a false aneurysm [3,5]. Pseudoaneurysms typically present as painless, pulsatile masses; however, as demonstrated in this case, they can also provoke sudden pain due to intra-articular extension following partial rupture into the joint space. Timely recognition and appropriate intervention are essential to prevent further vascular compromise and mitigate potential long-term morbidity [2–6].

The objective of this paper is to present a detailed case report and to conduct a comprehensive review of the literature regarding the rare complication of pseudoaneurysm that may arise following arthroscopic procedures.

Case Report

The patient is a 42-year-old man diagnosed with chronic instability of the left ankle and a chronic rupture of the anterior talofibular ligament following a running-related injury that led to persistent symptoms of instability and discomfort. The patient’s medical history included no significant comorbidities, and there was no prior surgical history related to the affected ankle or other relevant conditions. Despite approximately 12 months of conservative management, the patient experienced persistent mechanical instability and recurrent episodes of the ankle giving way during daily activities. Varus stress radiographs demonstrated a talar tilt angle greater than 20 degrees, warranting surgical intervention for stabilization. The patient underwent arthroscopic lateral ligament repair of the left ankle in the supine position, with the knee fully extended and the foot in a neutral position, utilizing both arthroscopy and ultrasound guidance. Ultrasound was employed to facilitate precise identification of anatomical structures and to minimize the risk of neurovascular injury. To minimize the risk of neurovascular injury, a distraction device was not utilized during the procedure, ensuring a safer operative environment for the patient. A tourniquet was applied during the procedure to maintain a bloodless field and enhance visualization. Standard anteromedial and anterolateral portals were established, with the anteromedial portal being created first using a #15 blade. Sterile saline was injected into the joint to distend the space before portal creation. Suture anchors were meticulously utilized to reattach the ligament to its anatomical footprint, ensuring precise fixation. At the 4-week postoperative follow-up, the cast was removed, and weight-bearing was initiated. DVT screening revealed a 2.4 cm thrombus in the calf vein, and the patient was started on a daily regimen of 100 mg aspirin. No additional complications, including pain, signs of infection, or any signs of acute limb ischemia, were noted at that time. At 6 weeks postoperatively, the patient suddenly experienced severe pain in the left ankle, rendering him unable to walk, with no history of recent trauma.

At the time of the emergency room visit, the patient exhibited overall pain, limited of motion, swelling, and mild heating sensation in the left ankle. The patient’s vital signs were stable, and no fever was present. To differentiate conditions such as septic arthritis, gout, and deep vein thrombosis in the left ankle, diagnostic tests were conducted. Laboratory results, including C-reactive protein (CRP), and uric acid levels, were within normal limits, indicating the absence of specific abnormalities. MRI was prioritized for the evaluation of intra-articular lesions due to the patient’s persistent pain. The MRI findings revealed a low signal intensity fluid around the ankle joint on the T2-weighted images, raising suspicion of a hemarthrosis (Figure 1). During the ultrasound examination performed to remove the hematoma, a pulsatile mass was identified in the anterior region of the ankle. Furthermore, Doppler ultrasound revealed a partial rupture of the anterior tibial artery, leading to the formation of a pseudoaneurysm (Figure 2). Consequently, the diagnosis was established as a pseudoaneurysm of the left anterior tibial artery and hematoma within the left ankle joint.

For the treatment of the pseudoaneurysm and hematoma, various options were considered, including conservative management, interventional procedures, and surgical intervention. Conservative management included rest, immobilization, and anti-inflammatory medications to reduce pain and swelling. However, due to the lack of symptom improvement with conservative management, the patient underwent interventional procedures.

The blood flow in the posterior tibial artery appeared normal, and the anastomosis between the anterior and posterior tibial arteries showed no abnormalities. During the interventional procedure, attempts were made to manage the wide-necked pseudoaneurysm using methods such as thrombin injection and balloon tamponade. Unfortunately, these interventions did not achieve the desired outcomes (Figure 3).

The following day, a plastic surgeon specializing in microsurgery attempted to reconstruct the anterior tibial artery; however, due to the extent of the rupture, vascular anastomosis was deemed unfeasible, leading to ligation of the artery (Figure 4).

A surgical evacuation of the hematoma was then performed (Figure 5). Following the surgery, the patient’s pain showed improvement. During outpatient follow-up, there was no recurrence of pain. One-year postoperative assessments indicated no reappearance of the pseudoaneurysm, demonstrating the sustained efficacy of the surgical repair.

Discussion

Complications following arthroscopic surgery in the foot and ankle can vary widely and occur with notable frequency, ranging from mild to severe [1–6]. Of these, approximately half are neurological in nature, with superficial infections being the second most commonly reported complication [4]. In addition, vascular injuries can also occur, and Mariani et al [5] reported an incidence of pseudoaneurysm due to vascular injury at 0.008%. The anteromedial portal is typically established as the initial step due to the reliably predictable presence of key anatomical structures. However, Veverková et al [7] documented the potential for injury to structures such as the saphenous nerve and the great saphenous vein during the insertion process of the anteromedial portal. Furthermore, there exists a risk of damaging the anterior tibial artery [4,8]. The anterior tibial artery is located in close proximity to the anterior ankle joint capsule at the level of the talar neck, coursing beneath both the superior and inferior extensor retinaculum. [9]. Yamada et al [10] reported variations in the position of the anterior tibial artery, with approximately 5.5% of cases exhibiting lateral deviation and 3.5% exhibiting medial deviation. In such instances, there is an increased risk of injury [9].

A pseudoaneurysm is a vascular anomaly characterized by an abnormal accumulation of blood outside the arterial or vascular wall. Unlike true aneurysms, pseudoaneurysms arise from a breach or injury to the vascular wall, leading to the development of a localized hematoma and the formation of a pseudo-arterial sac [11,12]. In cases of pseudoaneurysm occurring after foot and ankle surgery, symptoms of vascular injury are typically absent. Patients who sustain such an injury may present with atypical pain and swelling in the ankle following arthroscopy [6]. For these reasons, the diagnosis of pseudoaneurysms is more commonly established during the postoperative period rather than immediately following surgery [13]. In this case, a similar pattern was observed, with an initial improvement in pain following surgery. However, during the fourth postoperative week, as the patient resumed weight-bearing and ambulation, there was a worsening of pain. Subsequently, in the sixth postoperative week, the patient was diagnosed with a pseudoaneurysm following a visit to the emergency department.

The use of anticoagulants is recognized as a clinical concern that can increase the risk of pseudoaneurysm development [14]. The patient also developed postoperative deep vein thrombosis (DVT) with a 2.4 cm clot and was subsequently prescribed a daily dosage of 100 mg aspirin. It is conceivable that this medication regimen may have played a role in exacerbating the pseudoaneurysm and contributing to vascular complications.

Pseudoaneurysms can be diagnosed using various methods, including duplex ultrasound, CT, MRI, and angiography. The sensitivity and specificity of sonography and Doppler for diagnosing pseudoaneurysms are high, at 94% and 97%, respectively. The use of color Doppler further enhances accuracy, establishing it as the current criterion standard for diagnosing pseudoaneurysms [15–17]. In this case, MRI was selected as the initial imaging modality due to a greater clinical suspicion of intra-articular pathology rather than pseudoaneurysm. This approach was chosen to evaluate potential joint-related etiologies, including soft tissue or ligamentous injuries, prior to investigating vascular complications.

The treatment approach for aneurysms is primarily guided by their size and symptomatology. [18,19]. Small, asymptomatic aneurysms can be managed conservatively with regular monitoring through Doppler ultrasound. In contrast, large and symptomatic aneurysms of the anterior tibial artery generally necessitate interventional or surgical treatment. While conservative management may be appropriate initially, interventional or surgical treatment becomes imperative in cases of size increase, neurological symptoms from compression, pain, compartment syndrome, or concurrent infection [15]. Interventional treatments, such as thrombin injection and balloon tamponade, can be considered and have been reported to yield favorable outcomes [20]. Surgical treatment options for anterior tibial artery (ATA) aneurysms include ligation and resection. Additionally, procedures such as venous saphenous grafting have shown favorable outcomes in the management of tibialis posterior aneurysms [21]. In this case, various treatment modalities, including conservative management with rest, immobilization, and anti-inflammatory medications, as well as interventional procedures and surgical interventions, were considered. Techniques such as thrombin injection and balloon tamponade were employed but proved unsuccessful due to the extensive nature of the pseudoaneurysm. Consequently, surgical repair of the anterior tibial artery was attempted but found to be unfeasible, necessitating artery ligation and subsequent hematoma evacuation surgery.

Conclusions

This case underscores the rare occurrence of pseudoaneurysm as a source of acute pain after arthroscopic surgery, highlighting the importance of considering vascular complications. The sudden onset of symptoms was attributed to an intra-articular hematoma, emphasizing the need for thorough postoperative evaluation. Additionally, the careful usage of motorized instruments during arthroscopy is crucial to minimize the risk of vascular injury.