Before defining what is slap lesion, let’s talk about shoulder anatomy. The shoulder is made up of five joints and four linked bone groups, the main joint you see in anatomy books is the glenohumeral joint, Which is ball and socket joint, where the humeral head is the ball, and the glenoid fossa of the scapula is the socket because the humeral head is larger than the fossa and so the socket covers only a quarter of the humeral head, a tissue called glenoid labrum firmly attaches to the glenoid fossa to increase the articular surface area and stabilise the glenohumeral joint.
SLAP is short for Superior Labrum Anterior to Superior. And it’s defined as Lesions of the superior aspect of the glenoid labrum that extend anteriorly and posteriorly to the biceps insertion Snyder et al.(1990)
The glenoid labrum is a ring of fibrocartilaginous surrounding the glenoid cavity, It increases the shoulder’s depth, stability and shock absorption capacity, it is also a site of attachment for the joint capsule, the glenohumeral ligaments, and the long head of the biceps tendon. Approximately 50% of the biceps tendon fibres attach to the superior labrum and the other 50% to the supra-glenoid tubercle as evidenced by Vangsness et al.(1994) who studied 105 cadaveric shoulders to elucidate (clarify) the origin of the long head of the biceps tendon and its relationship to the superior labrum and supraglenoid tubercle. In those shoulders examined, 40-60% of the biceps tendons originated from the supraglenoid tubercle with the remaining fibres attached to the superior labral complex.
The superior and anterior region of the labrum has the poorest blood supply, and it is hypothesised that this contributes to a slower healing process.
Snyder et al.(1990) developed a system of classification for SLAP tear into 4 distinctive types.
Type 1: Fraying and degeneration of the superior labrum with intact biceps attachment.
Type 2: bucket handle tear of superior labrum And biceps anchor. most common type 55%.
Type 3: bucket handle tear of superior labrum with intact biceps labrum 9%.
Type 4: bucket handle tear of the superior labrum that extends into their biceps tendon 10%.
Signs & Symptoms:
It has been recognised that athletes who do repetitive overhead activities, especially tennis, baseball players and swimmers, develop asymmetries in the ranges of internal and external rotation. This is usually characterised as an increase in the external rotation that is associated with a similar decrease in internal rotation, leaving the total arc of rotation symmetrical.
Chang et al (2008) and Sanghavi & Lam (2011) describe the various symptoms experienced by individuals with SLAP lesions as shown in this diagram
Mechanism of Injury:
The most commonly cited mechanisms of injury include traction and compression of the shoulder; although, in many instances, no antecedent trauma is remembered. Overhead athletes may complain of pain during a specific phase of throwing, most notably the late cocking phase. A subsequent study found that the most common mechanism of injury was a fall or direct blow to the shoulder, occurring in 31% of patients.
Numerous tests have been described to be specifically designed to determine the presence of labral pathology, including the active-compression test, the compression-rotation or grind test, Speed’s test, the clunk test, the crank test, the anterior slide test, the biceps load test, the biceps load test II, and the pain provocation test. However, Cook et al. (2012) is one of many studies to show that clinical tests have difficulty diagnosing a SLAP lesion and that subjective history and other clinical findings must be considered as a SLAP lesion is a complex problem typically associated with additional complications, MRI is usually the gold standard method for diagnosing SLAP lesions although x-ray may be used to rule out other possible diagnoses such as fractures.
Conservative management of SLAP lesions is often unsuccessful, particularly when there is a component of glenohumeral joint instability or when a concomitant rotator cuff tear is present. There may be, however, a small subset of patients, particularly those with type I SLAP lesions, who are amenable to conservative treatment. The initial phase of conservative management consists of cessation of throwing activities, followed by a short course of anti-inflammatory medication to reduce pain and inflammation. Once the pain has subsided, we initiate physical therapy focused on restoring normal shoulder range of motion. Strengthening of the shoulder girdle musculature is also crucial to restore normal scapulothoracic motion.
A particular emphasis should be placed on stretching the posterior capsule and restoring internal rotation, a strengthening phase, which includes trunk, core, rotator cuff, and scapular musculature should be planned.
Here are some of the rehab exercises to do at home to manage Slap lesion Type 1 & 2.
Snyder, S.J., Karzel, R.P., Del Pizzo, W., Ferkel, R.D. and Friedman, M.J., 2010. SLAP lesions of the shoulder. Arthroscopy, 26(8), p.1117.Vangsness Jr, C.T., Jorgenson, S.S., Watson, T.R.O.Y. and Johnson, D.L., 1994. The origin of the long head of the biceps from the scapula and glenoid labrum. An anatomical study of 100 shoulders. The Journal of bone and joint surgery. British volume, 76(6), pp.951-954.
Vangsness Jr, C.T., Jorgenson, S.S., Watson, T.R.O.Y. and Johnson, D.L., 1994. The origin of the long head of the biceps from the scapula and glenoid labrum. An anatomical study of 100 shoulders. The Journal of bone and joint surgery. British volume, 76(6), pp.951-954.
Chang, D., Mohana-Borges, A., Borso, M. and Chung, C.B., 2008. SLAP lesions: anatomy, clinical presentation, MR imaging diagnosis and characterization. European journal of radiology, 68(1), pp.72-87.
Cook.C, Beaty.S, Kissenberth.MJ, Siffri.P, Pill.SG and Hawkins.RJ (2012) Diagnostic accuracy of five orthopaedic clinical tests for diagnosis of superior labrum anterior-posterior (SLAP) lesions Journal of Shoulder and Elbow Surgery Vol 21 Issue 1 pp 13-22.
Dodson CC, Altchek DW. SLAP lesions: an update on recognition and treatment. J Orthop Sports Phys Ther. 2009 Feb;39(2):71-80. doi: 10.2519/jospt.2009.2850. PMID: 19194018.