[Shoulder arthroscopy. Partial thickness tears of the rotator cuff.]

Partial tears are frequent in rotator cuff pathology. Articular-side lesions, bursal-side lesion and interstitial lesion inside the thickness of the tendon are described. Etiopathogeny is not clearly known. It seems a multifactory association with intrinsic tendinous factors (vascularity, normal ageing of the tendon), extrinsic mechanical factors (impingement syndrome) and trauma. Clinically, the complaint is a painful shoulder with full range of motion. The rotator cuff examination does not shown weakness but pain. The onset is traumatic or degenerative. It could be the consequence of overuse specially in case of overhead sport. Diagnosis is confirmed by arthro-CT or/and (arthro) MRI. It is useful for the treatment to determine the size of the rupture regarding the thickness of the tendon. Natural history shows that partial tears do not healed. Treatment of the partial tear of the cuff is still debatable particularly for intertstitial lesion (acromioplasty, debridment, repair). Isolated acromioplasty permit to obtain pain relief but do not prevent evolution to full-thickness tear when the lesion concern more than 50% of the thickness of the tendon. In this case, arthroscopic tendon repair gives good and reliable results.