Background and Purpose: Partial thickness rotator cuff tears (PTRCTs) are a common pathology that may significantly impact a spectrum of patients including sedentary individuals, workers, and athletes. Despite their high prevalence, the majority of studies on the treatment of rotator cuff tears have focused on full-thickness tears. PTRCTs have been relatively ignored and subsequently the treatment of PTRCTs remains controversial. The purpose of this review was to evaluate the current state of knowledge regarding PTRCTs including etiology, incidence of site of tear (articular, bursal and interstitial).

Patient and Methods: During the period June 2019 through June 2021, we prospectively studied all patients aged 18–75 years with acute onset of pain after shoulder trauma, with limited active abduction, and with normal conventional radiographs. 171 consecutive patients met these inclusion criteria. The patients had a median age of 51 (18–75) years 65% were males. The patients were divided into 3 groups according to the clinical findings: group I, suspected Rotator Cuff tear (RCT); group II, other specific diagnoses; and group III, sprain. Semi-acute MRI was performed in all patients in group I and in patients in group III who did not recover functionally. Based on MRI findings Incidence on site (articular, bursal, interstitial) of partial thickness rotator cuff tear was found.

Results: We identified 75 patients with PTRCTs. The estimated annual incidence of MRIverified acute PTRCT was 16 (95% CI: 11–23) per 105 inhabitants for the population aged 18–75 years and 25 (CI: 18–36) per 105 inhabitants for the population aged 40–75 years. The prevalence of acute PTRCT in the study group was 75/171 (23%, CI: 18–28). The tears were usually large and affected more than 1 tendon in 36 of these 60 patients. The subscapular is was involved in 38 of the 60 patients.

Interpretation: Acute partial thickness rotator cuff tears are common shoulder injuries especially in men, throwing athletes. They often involve supraspinatus tendon and common site being the articular side.