Biomechanical studies of SLAP tears
Authors: L Funk, 2006
Biomechanical studies have found that simulated type II SLAP lesions result in increased glenohumeral translations in both the anteroposterior and superoinferior directions (Pagnani et al. JBJS 1995). Translations were increased regardless of whether the type II SLAP lesion was completely detached or elevated in a periosteal sleeve (McMahon et al. JSES 2002). Likewise the torsional rigidity of the shoulder was diminished after simulation of a type II SLAP lesion and strain at the inferior glenohumeral ligament was increased (Rodosky et al. AMJ Sport Med 1994).
Even though repair of a type II SLAP lesion has been advocated, study of its affects on joint stability remains unknown. Recent studies compare translations of the glenohumeral joint with a simulated type II SLAP lesion to translations after its repair and to translations of the vented shoulder (Burkart et al. AMJ Sport Med 2002). A robotic universal force testing system was used to simulate load and shift tests by applying anterior, posterior and inferior loads. Glenohumeral translation was increased regardless of severity after simulation of type II SLAP lesions (McMahon et al. JSES 2002). Repair of the type II SLAP lesion only partially restored translation to that of the vented shoulder. In surgically treating a type II SLAP lesion, one should also consider repairing the passive stabilisers that may be injured with this lesion.