A benign and locally aggressive tumor, aneurysmal bone cysts (ABCs) can develop in any bone but are more common in the metaphysis of long bones. They are distinguished by fibrous septa that divide blood-filled compartments. Particularly when they affect bones such as the proximal humerus, ABCs can result in discomfort, edema, and functional restrictions. High rates of morbidity and recurrence have been reported with curettage and bone grafting, the conventional treatment [1-4]. Due to this, a number of other therapeutic methods have been investigated, including radiation, embolization, broad excision, sclerotherapy using various agents, and more ^[5]. Comparing percutaneous sclerotherapy to open surgery, it has demonstrated excellent outcomes in recent years, with similar recurrence rates and lower morbidity, especially when combined with polidocanol, alcohol, or doxycycline ^[6].

Patient

A 10-year-old female patient arrived at our outpatient department with a history of recurring discomfort, edema, and limited movement in her right shoulder and proximal 1/3^rd of her right arm.

Clinical history

Over the course of several months, the patient’s right shoulder gradually became more uncomfortable and occasionally painful. The patient’s activities of daily living and sleep were disrupted due to an increase in intensity of pain and discomfort. She had trouble reaching behind her back and lifting her right arm over shoulder level. She experienced pain over right arm while doing daily activities.

Diagnostic workup

Physical examination

On palpation, tenderness was felt over the right proximal humerus during the clinical examination. A gentle, non-fluctuant enlargement that measured around 5 cm in diameter was confirmed by palpation, started with peanut size to current size. There was no bruit and the swelling was not pulsatile. Restricted shoulder flexion, abduction, and external rotation were found during the range of motion assessment.

Radiological investigations

X-ray and magnetic resonance imaging (MRI) were done. X-ray showed A lytic, well-defined lesion involving the proximal humerus that is expansile (Fig. 1). The lesion appeared like soap bubbles, indicative of an ABC (Fig. 2). No signs of a pathological fracture or cortical breach. MRI showed a cystic lesion involving the proximal humerus that is multiloculated, fluid-filled levels in the lesion were compatible with the presence of serous fluid and blood, lesion appeared to be divided into several compartments by thin septae and absence of soft-tissue involvement or extraosseous extension.

Patient selection for percutaneous sclerotherapy

The patient was considered a good candidate for percutaneous sclerotherapy due to her age, the location and size of the lesion, and her general health. After carefully evaluating her situation, the multidisciplinary team – which included radiologists and orthopedic surgeons-decided that sclerotherapy presented the best possibility of a successful outcome with the least amount of invasiveness.

Management

It was managed with percutaneous sclerotherapy with a polidocanol injection due to the lesion’s benign nature. General anesthesia was used for the sclerosing procedure. Under fluoroscopic supervision, a 1.0- or 1.2-mm trocar needle was used to puncture the cyst percutaneously. According to Brosjö et al., 4 mg of polidocanol per kilogram of body weight was injected into the cyst along with the contrast agent iohexol. The trocar-tipped needle was inserted into each cystic area before injection to rupture any potential septae. To make sure the entire cyst was treated, a contrast agent was employed during the injection. To stop extravasation, pressure was applied to the injection site for at least 2 min after the needle was removed and flushed with saline or previously aspirated blood. The course of treatment comprised three injections spaced 4 months apart, all done with a C-arm radiological guidance. Polidocanol regulates the vascularity of the ABC due to its ability to cause endothelial damage those results in thrombosis.

Follow-up

The patient experienced significant symptom improvement after the injectionnd there were no acute post-operative problems. Monthly progress reports were started, and after 3 months, physiotherapy was added to improve shoulder range of motion because there were no indications of a recurrence (Fig. 3).

Two-year follow-up

The important 2-year follow-up showed continued improvement and no indications of a relapse. The patient had a good range of motion, her shoulders demonstrated how well percutaneous sclerotherapy had worked to relieve symptoms and promote functional recovery, serial X-rays were done and it was satisfactory (Fig. 4-10).

The effectiveness of polidocanol-based percutaneous sclerotherapy in treating ABCs has been thoroughly investigated, with encouraging results and a favorable safety profile. Rastogi et al. (2022) conducted a retrospective analysis of seventy-two individuals receiving polidocanol sclerotherapy for primary ABC which showed 75% success rate after a year and a 97% success rate after 2 years. No significant problems were noted. Otte et al. (2021) reported a prospective investigation using repeated injections of polidocanol to treat 38 patients with ABC. After a median of four polidocanol instillations, all lesions but one healed. Minimal adverse effects and high efficacy were noted. Batisse et al. (2020) did a retrospective analysis of 19 ABC patients who received sclerotherapy. At 3 months’ follow-up, 85% of patients had complete ossification, and the remaining 15% had incomplete ossification. At the 2-year follow-up, no recurrence was noted. Liu et al. (2019) conducted a meta-analysis encompassing 12 studies and 421 ABC patients undergoing polidocanol sclerotherapy. At a mean follow-up of 28.5 months, the total success rate was 87.2%. Wang et al. (2018) did a comprehensive analysis of ten studies with 302 ABC patients receiving polidocanol sclerotherapy. The combined success rate at a mean follow-up of 26.4 months was 89.1%. All of these studies support the use of polidocanol in percutaneous sclerotherapy as a management strategy for ABCs. For patients who have lesions in easily accessible places or who are pediatric patients, this procedure is a helpful therapeutic option due to its positive safety profile, minimum invasiveness, and high success rates.

For pediatric patients with proximal humerus ABCs, percutaneous sclerotherapy combined with polidocanol is a safe and efficient therapeutic option that relieves symptoms while maintaining shoulder function [7, 8]. Since it reduces the chance of problems and maintains bone growth and function, this minimally invasive procedure is especially beneficial for kids and teenagers. To achieve the best results, a multidisciplinary approach and careful patient selection are crucial [9, 10].

This case underscores the potential role of sclerotherapy as a primary treatment option for ABCs, especially when considering the advantages of reduced surgical morbidity and functional preservation in key anatomical areas like the shoulder joint.