As anterior GH instability captures about 98% of traumatic dislocations, I will focus this discussion on treatment within this patient population.2 Evaluation items included should be assessment and grading of laxity with sulcus demonstrating inferior instability and load shift screening ant/posterior laxity. With 85% of primary traumatic dislocations sustaining Bankart lesion, and 80% having Hills Sach’s lesion, either imaging or assessment of labrum and consideration of possible fracture should be appreciated.2 Atraumatic dislocations are multifactorial and possibly due to impairments within rotator cuff weakness, and connective tissue abnormalities.2
Attention of this conversation is how effective we are in treatment of this condition. Objective markers of success will be decreasing likelihood of re-disclocation and return to function. Seemingly from the literature we are moderately effective in obtaining these objectives in primary traumatic dislocators ranging from 75-83% of patients obtaining subjective successful outcomes.2 Of note, primary population captured in office will be their 2nd or 6th decade of life, and re-occurrence rates are of much higher at 20 years or younger.2
Management of first time dislocators is up for debate, especially in terms of immobilization periods. A preliminary case report by Deyle et al brought up excellent point of conservative immobilization for 6 weeks to allow healing. His report assessed a 19-year and first time dislocator. After the 42 days of immobilization, he saw excellent improvement in ROM and strength. Of higher interest to the reader is his 20-month follow up DASH score of 2.5, and reports of full function with no re-dislocations. As reiterated above, re-dislocation rates in this age group are commonly 94%, this is considered a success.9 Although Hovelius et al found re-dislocation rates in 47% of the patients in his age range with 3-4 weeks of immobilization. Another study of large sample size reports 33% re-dislocation rates with immobilization periods being that of 6 weeks duration. Although – these commonly referenced pieces of literature were both in mid-1980’s. In defense of our profession the strength in our treatments has only improved as we gain understanding of biomechanics and proprioceptive data and impairments in this population – leaving me to speculate if we re-trialed these to date if findings would reflect that of Deyle et al.
As discussed in previous weeks, shoulder may take “path of least resistance” vs. capular patterning for movement. Therefore management of posterior tissue restriction is of increasing importance to ensure the path the shoulder prefers, is not anterior. Debate of posterior restriction being that of capsule or hypertonicity of rotator cuff is of relevance, but possibly little clinical utility. It is speculated this posterior cuff tissue restriction comes from higher subscapularis–infraspinatus and supraspinatus–infraspinatus coactivation above the level of the shoulder where pain is typically present (90–120° of humeral elevation).4 A clinical pearl from Dr. Mintken at our recent national conference is to find restriction and see if you can contract-relax into further internal rotation to differentiate if this is a soft tissue limitation, or a capsular one. Manually, I find the point of restriction and mobilize into it with patient comfort and ease. Followed by maintaining mobility gained with horizontal adduction stretching over sleeper stretching due to McClure et. al article in 2009 demonstrating a more effective stretch with this technique.3
Stability exercises should be of highest importance with this population. A place of personal improvement is progression and sustaining patient relationship until proprioception, and dynamic stability is improved. Fortunately, a local hero, Dr. Leudwig has numerous articles reviewing biomechanical properties of shoulder behaviors. In terms of patients with GH instability, her literature demonstrates greater scapular internal rotation and less scapular upward rotation, and/or greater scapulohymeral rhythm.8 Other findings of her work include scapular “winging” or serratus inferior weakness, specifically in this population. As a therapists goal should be to maintain proper seating of the humerus in the glenoid, lack of upward rotation of the scapulae needs to be considered to maintain as much stability as possible in the vulnerable abducted, and externally rotation position.8
In conclusion, glenohumeral instability seems simplistic in static positioning, but as patients commonly demonstrate instability complaints in extreme shoulder positions, the story becomes more complex. Review of current discrepancies in our literature exposed a few things: increased timing in a sling, slow progression back to sport, and dynamic considerations of proprioception and control of GH joint through unstable open packed positioning. Seemingly, if we can get these moons to align, hopefully re-occurrence rates with start to drop.
Original post: October 26, 2013
References:
1) Guerrero P, Busconi B, Deangelis N, Powers G. Congenital Instability of the Shoulder Joint: Assessment and Treatment Options. Journal of Orthopaedic and Sports Physical Therapy. 2009; 29: 124-135.
2) Hayes K, Callanan M, Walton J, Paxinos A, Murrell GA. Shoulder Instability: Management and Rehabilitation. Journal of Orthopaedic and Sports Physical Therapy.
3) McClure P, Balaicuis J, Heiland D, BroersmaME, Thorndike CK, Wood A. A randomized controlled comparison of stretching procedures for posterior shoulder tightness. J Orthop SportsPhys Ther. 2007;37:108-114. http://dx.doi.org/10.2519/jospt.2007.233
4) Myers JB, Hwang J, Pasquale MR, Blackburn TJ, Lephart SM. Rotator Cuff Coactivation Ratios in Participants with Subacromial Impingement Syndrome. Journal of Science and Medicine in Sport. 2009; 12: 603-608.
5) Deyle G, Nagel KL. Prolonged Immobilization in Abduction and Neutral Rotation for a First-Episode Anterior Shoulder Dislocation. Journal of Orthopaedic and Sports Physical Therapy. 2007; 37: 192-198.
6) Hovelus L, Eriksson K, Fredin H, et al. Recurrences After initial dislocation of the shoulder. Results of aprospective study of treatment. J Bone Joint Surg Am.1983;65:343–349.
7) Simonet WT, Cofield RH. Prognosis in anterior Shoulder Dislocation. Am J Sports Med. 1984;12:19–24.
8) Ludewig PM. Reynolds J. The Association of Scapular Kinematics and Glenohumeral Joint Pathologies. JOSPT. 2009; 39: 90-115.
9) Lecture notes from Paul Mintken. Orthopedics 2. 2008.