Prevalence and Associated Injuries in Patients With Knee Cysts: An Epidemiological Study

Document Type

Conference Proceeding

Publication Date

2-2025

Abstract

INTRODUCTION: With the growing utilization of magnetic resonance imaging (MRI) for assessing the knee joint, the findings of incidental cystic and “cyst-like” lesions have also seen an increase. [1-3,6,7] Associated symptoms vary depending on the size, location, and association with adjacent anatomic structures and span a diverse group of entities ranging from benign cysts to complications of underlying disease processes. [3,4] These lesions can be further subclassified into true cysts (synovial cysts, bursae, ganglia, and meniscal cysts) and lesions that mimic cysts (hematomas, seromas, abscesses, vascular lesions, and neoplasms). [5] Determining the associated symptoms and findings that correspond to these various cystic and cyst-like lesions within the knee joint, compared to more advanced pathologies, is clinically important. Although many studies have examined the appearance of benign cystic masses on knee MRI, few studies have evaluated associations between these lesions and their corresponding injuries - information that could guide future diagnostic and clinical decision-making processes. The aim of this study is to assess the incidence of various cysts in the knee and evaluate associated injuries, such as concomitant joint effusion, meniscal tears, and knee OA. Our study will aid physicians in appropriate characterization of cysts within the knee and prevention of misdiagnosis or unnecessary clinical work up. METHODS: This was a retrospective review of knee MRIs from January 1st, 2022 to January 1st, 2023. Inclusion criteria included patients aged over 18 years old and presence of a ‘cyst’ noted on report. Exclusion criteria included patients without identified cyst on MRI or subchondral cysts. Data that was collected included demographics, cyst type, and associated injuries. RESULTS SECTION: When assessing patients with Baker’s cysts, the average age of patients with a cyst was 61.49 (12.01) vs. no Baker’s cyst 57.75 (14.01) (p < 0.001). Furthermore, the prevalence of female patients (591) vs. male patients (331) (p=0.042). Notable associated injuries for those with Baker’s cysts vs. no Baker’s cyst include bursitis (59:30) (p=0.027), cartilage damage (672:186) (p=0.017), effusion (619:165) (p=0.006), medial meniscal tear (661:185) (p=0.032), PCL injury (22:18) (p=0.002), and subchondral fracture (53:5) (p=0.004). Notable associated injuries for those with Ganglion cysts vs. no Ganglion cysts include ACL injury (50:111) (p=0.002), medial meniscal tear (159:687) (p=0.002), osteoarthritis (145:448) (p=0.009), PCL injury (21:19) (p < 0.001), plica (7:8) (p=0.024), synovitis (43:91) (p=0.002), tendinopathy (62:143) (p < 0.001). Notable associated injuries for those with Meniscal cysts vs. no Meniscal cysts include medial meniscal tear (9:837) (p=0.002). The average age of a patient with a parameniscal cyst 58.15 (14.14) vs. patients with no parameniscal cyst 61.02 (12.29) (p=0.039). Notable associated injuries for those with a Parameniscal cyst vs. no Parameniscal cyst include bursitis (24:65) (p=0.001), effusion (88:696) (p < 0.001), lateral meniscal tear (87:354) (p < 0.001), medial meniscal tear (139:707) (p < 0.001), osteoarthritis (68:525) (p=0.008). DISCUSSION: From our study, we observed that Baker’s cysts were most common of the cyst type and had a prevalence amongst older female patients. Seen with these Baker’s cysts, we noted increased rates of bursitis, cartilage defects, effusion, medial meniscal tears, PCL injuries, and subchondral fracture. Ganglion cysts were noted to have ACL and PCL injuries, medial meniscal tears, osteoarthritis, plica, and tendinopathy. Meniscal cysts are associated with medial meniscus tears. Parameniscal cysts were commonly found amongst younger male patients, and associated with bursitis, effusion, lateral and medial meniscal tears, and osteoarthritis. One question is the dichotomic pondering of which came first, the injury or the cyst? Current literature suggests that these cysts are a secondary phenomenon. [4] Our study was limited by a sample size from a singular institution, MRI reports from numerous different radiologists, and our patient population being predominantly white, making these data more difficult to generalize. Moving forward, we aim to analyze the incidence of isolated cysts vs. multiple associated injuries and to assess the economic impact of incidental knee cyst findings. SIGNIFICANCE/CLINICAL RELEVANCE: Through gaining a better understanding of the epidemiological aspects of some of the more prevalent knee cysts in our patient population, and their associated injuries, we hope to aid in clinical determination and insight into identifying potentially sources of knee pain. [7]

Comments

ORS (Orthopaedic Research Society) 2025 Annual Meeting, February 7-11, 2025, Phoenix, AZ

Link to Full Text

Share

COinS