Incidence of tendinosis in the medial head of gastrocnemius muscle and associated patologies

OBJECTIVE: Tendinosis, a common tendon pathology, is often overlooked clinically and radiologically, although it is one of the causes of pain behind the knee joint, especially when it occurs in the medial head of the gastrocnemius muscle. This study aimed to determine the prevalence and severity of medial gastrocnemius tendinosis in the population by magnetic resonance imaging (MRI) of the knee joint and to determine the relationship, if any, with other MRI findings and pathologies on orthoroentgenogram. MATERIALS and METHODS: Patients who underwent both knee MRI and orthoroentgenogram in the same month between January 2022 and December 2023 at Ankara Bilkent City Hospital were included in the study group. Patients younger than 20 years of age, patients with a history of trauma and surgery, and patients with tumoral lesions were excluded. A total of 600 patients (299 males and 301 females) who met the inclusion criteria were included in the study. Knee joint medial and prepatellar subcutaneous adipose tissue thickness was considered as an indirect indicator of body mass index. Conventional MRI and orthoroentgenogram images were retrospectively evaluated by two radiologists using the Ankara Bilkent City Hospital workstation. RESULTS: The average age of the study participants was 45.44, and medial gastrocnemius tendinosis was detected in a total of 226 (37.66%) patients, including Grade 2 in 200 (33.33%) patients and Grade 3 in 26 (4.33%) patients. Age of the patients ranged from 20 to 80 years. There was a statistically significant difference in age, lateral gastrocnemius tendinosis frequency, meniscus pathologies, intraarticular effusion, anterior cruciate ligament pathologies, edema in the infrapatellar fat pad, bone marrow edema in the femur medial condyle and tibia medial plateau, Baker's cyst frequency, medial and prepatellar subcutaneous fat tissue thickness which are indirect indicators of body mass index, patellar ve medial femoral chondromalacia, lateral ve medial collateral ligament and presence of gonarthrosis between patients with medial head of gastrocnemius tendinosis and normal group (p<0.05). CONCLUSION: With the increasing use of MRI scans of the knee joint, it is important to be aware of the presence of tendinosis in the medial head of the gastrocnemius muscle, as it can coexist with other joint pathologies. This awareness will aid diagnosis and support treatment. Keywords: Gastrocnemius muscle, tendinopathy, tennis leg, MRI, knee