Chronic expanding hematomas arising over a decade post primary total hip arthroplasty.

Background: Chronic expanding hematoma (CEH) is an infrequent yet serious complication following total hip arthroplasty (THA). Mismanagement of this condition can result in severe consequences. The purpose of this study is to conduct a retrospective analysis of patients who developed CEH after THA at our institution over the past 20 years, complemented by a review of the existing literature. This comprehensive approach aims to contribute valuable clinical insights into the diagnosis and management of CEH. Methods: In this study, we conducted a retrospective study of patients who had undergone THA within the past two decades and subsequently developed CEH during their follow-up period at our institution. The data collected encompassed fundamental patient demographics, including age, gender, and specifics regarding the primary THA implants. Additionally, we gathered preoperative, postoperative, and follow-up imaging studies. Following the data compilation, a thorough literature review was performed to aggregate and analyze the published cases of CEH occurring post-THA. Results: Our follow-up data identified five patients who developed CEH more than ten years after undergoing THA. In one case, CEH manifested subsequent to a traumatic event, while the remaining four cases were non-traumatic. The outcomes following revision surgery were heterogeneous: two patients showed no indications of recurrence throughout a least follow-up period of over one year, one patient eventually underwent amputation, and two patients developed periprosthetic joint infection (PJI), an ongoing management challenge. Our literature review revealed nine previously reported cases with similar clinical features. A summary is as follows: Etiology: While often linked to trauma or surgery, a definitive cause is not always present. It is hypothesized that inadequate hemostasis during the initial procedure may contribute to the development of CEH. Time Course: The condition typically evolves slowly over an extended period of years. Mechanism: The underlying mechanism remains unclear. Diagnosis: MRI: T2-weighted sequences exhibits a combination of hypointense and hyperintense signals reflecting a blend of fresh and old blood, indicative of recurrent hemorrhage. Isointense or slightly high signals on T1-weighted sequences. Histological Features: Characterized by three distinct aspects: a peripheral wall densely encapsulated in fibrous tissue; fresh and mobile blood clots; and a central zone of loose connective tissue formation. Differential Diagnosis: Includes inflammatory pseudotumors, hemophilia, and malignant neoplasms, among others. Treatment: The gold standard of care involves complete surgical resection, inclusive of the capsule. Given CEH's propensity for progressive bone resorption, it is recommended that once identified, patients undergo regular follow-ups every 2-3 months. Should significantly bone loss be detected, surgical excision of the mass should be contemplated. Conclusion: CEH is a rare complication that can arise following THA, typically exhibiting a slow progression over a period of years. Given the potential for devastating consequences if mishandled, vigilant follow-up care is essential to ensure timely identification and immediate treatment of CEH upon detection. The translational potential of this article: This study enhances diagnostic accuracy, optimizes treatment, improves prognosis, reduces medical costs, and promotes the update of guidelines for the rare disease CEH after THA.