Updates in Partial Thickness Rotator Cuff Tears

The etiology and pathogenesis of PTRCTs is likely multifactorial with both intrinsicand extrinsic factors contributing to an individual’s rotator cuff lesion. Intrinsicfactors, including age-related microscopic changes5-1. Extrinsic factors, includingsubacromial impingement, glenohumeral instability, and internal impingement, canfurther contribute to anatomic pathology8-6. Finally, traumatic events, either singularin nature or repetitive (e.g., overhead athlete), can eventually contribute to tensileoverload and fiber failure of the rotator cuff.While still unclear, the presumptionis that because of increased tendon strain due to the presence of a tear, PTRCTsgenerally increase in size over time4.A number of more current studies have suggested that PTRCTs may not progressas rapidly as previously presumed12-10. Furthermore, they showed a significantcorrelation between the risk of tear progression and percentage of the tendonthickness involved at presentation. In patients with tears involving ≥ %50 of thetendon thickness, %55 had tear progression; whereas, in patients with tearsinvolving < %50 of the tendon thickness, only %14 had tear progression. Also PTRCTsare secondary to age-related degenerative change within an altered biomechanicalenvironment, progression of the tear can occur10.The majority of imaging studieshave demonstrated that healing of PTRCTs is, in fact, rare9,11,13.This is furthersupported by histologic studies by Fukuda et al.14,15 who demonstrated that PTRCTsdid not have the ability to heal themselves over time. Furthermore, it appears thatnonanatomic procedures that do not specifically address the PTRCT do not preventtear progression. In one study by Hyvonen et al.93 16 patients were followed foramean of 9 years following subacromial decompression for impingement syndrome.However, subacromial decompression did not appear to prevent the progression ofrotator cuff tearing.Based on cadaveric and imaging studies, the prevalence of PTRCTsranges from %13 to %32, in part, related to its strong correlation to patient age20-17.However, the true prevalence of PTRCTs may in fact be underreported. Investigationof 249 cadaveric supraspinatus tendons revealed that %13 had PTRCTs, of which %55were intratendinous22,23. In one MRI study of asymptomatic individuals [28], theoverall prevalence of PTRCTs was 20.%20 There is a linear increase in the prevalenceof rotator cuff tears after the 5th decade of life.21 Similarly, the prevalence of PTRCTsis surprisingly high in overhead athletes....