The shoulder is a unique joint with a greater range of motion than most other articulations in the body. The trade-off for this range of motion is an increased risk of instability, or dislocation, specifically of the glenohumeral joint, which is the most commonly dislocated joint in the body. Glenohumeral instability is especially common in adolescent and young adult patients, primarily due to their involvement in activities such as contact sports. However, older patients do have a risk of shoulder instability, most often related to falls. This chapter focuses on the management of shoulder instability in patients over the age of forty.
A 48-year-old right hand dominant woman presents with a painful left shoulder one day after she slipped and fell on an icy sidewalk. When she fell, she was carrying a bag of groceries in her right hand and attempted to break her fall with an outstretched left arm. When her left hand hit the ground, she felt a sharp pain in her left shoulder associated with a tearing or stretching sensation. She has not been able to lift the arm since the fall and noted bruising around her shoulder and proximal arm several hours later. She could not sleep last night due to the pain in her shoulder. She denies any neck pain. She does note some tingling sensations in her left forearm and thumb but denies any distal weakness. She has no previous history of shoulder complaints.
The skin overlying her left shoulder is intact, with ecchymosis over her anterior shoulder tracking into her anterior and lateral proximal arm. Her left shoulder is diffusely tender, with the most tenderness over her anterior joint and anterior and lateral proximal arm. She can actively forward flex up to 45 degrees and actively abduct up to 35 degrees, limited by pain. Passive forward flexion is 105 degrees and passive abduction is 80 degrees. She guards against more than 20 degrees of external rotation. She cannot bring the left hand posterior to midline to test internal rotation. She cannot hold her left arm in position to test supraspinatus strength. External rotation strength is 5-/5 on the left with mild pain compared to the right. Distal left upper extremity strength, sensation, and circulation is intact.
Plain radiographs of the left shoulder including four views demonstrate a reduced glenohumeral joint, no fracture, a Hill-Sachs lesion on the humeral head, and mild degenerative changes of the acromioclavicular joint.
A magnetic resonance image (MRI) of the left shoulder demonstrates a Bankart lesion with displaced anteroinferior labral tear, a small Hill-Sachs lesion and a 2 x 2 cm full thickness tear of the supraspinatus tendon insertion. The subscapularis, infraspinatus, and teres minor tendons are intact. There is no fatty infiltration of the rotator cuff musculature. Mild degeneration is noted at the acromioclavicular joint.
The vast majority of shoulder dislocations in patients over the age of 40 can and should be treated non-operatively. Patients typically should have a short period of immobilization, typically in a sling. Gentle range of motion using pendulums and passive range of motion in the seated or supine position should be started soon after evaluation.
Immobilization should be discontinued as soon as patients are comfortable without support, usually within 1-2 weeks, and supervised physical therapy is recommended to safely restore range of motion and strength. Use of the shoulder is slowly advanced as tolerated, with limited lifting and avoidance of overhead or contact activities for some time. Full recovery can be expected within 3-6 months. Fortunately, the rate of recurrence is lower for patients over the age of 40 compared to those under 40, but it is not zero.
Indications for Surgery
Indications for surgery include the presence of a traumatic full thickness rotator cuff tear resulting from the dislocation and failure of conservative management with persistent or recurrent symptomatic instability.
Modern techniques allow for arthroscopic treatment of these injuries. Stabilization can be performed with the patient in the beach chair position or the lateral decubitus position. As most surgeons prefer to treat rotator cuff tears in the beach chair position, patients over the age of 40 being treated for shoulder instability will most likely undergo arthroscopic surgery in that position to address known or possible associated cuff tears. Patients will often receive a regional block with or without an in situ (nerve) pain pump to help with post-operative pain control as well as general anesthesia during the procedure.
Once anesthesia is administered, the patient is positioned. A careful examination under anesthesia is performed to document range of motion and joint (in)stability. It is helpful to compare the injured shoulder to the contralateral (normal) shoulder. The patient is then prepped and draped.
The bony landmarks of the shoulder are palpated and marked, guiding placement of arthroscopic portals. Typically the posterior shoulder portal is made first, inferior and medial to the posterolateral corner of the acromion.Once the scope is placed in the glenohumeral joint, an anterior portal is made in the appropriate position to facilitate access to the anteroinferior glenoid and labral tear. A second accessory anterior portal can be used but is not mandatory. An arthroscopic “drive through” sign is often present, whereby the scope can easily be advanced between the humeral head and glenoid into the anteroinferior joint space.
Once adequate access has been achieved, the labral tear is identified and inspected. It may need to be mobilized off the glenoid neck to facilitate repair. The anteroinferior rim of the glenoid is then prepared with a shaver so the labrum will be tied down to exposed bone.
Once the labrum and glenoid are adequately prepared, surgeon preference dictates whether the initial step consists of placing passing sutures in the labrum or anchors in the glenoid. The first anchor must be placed as low as possible on the glenoid to repair the most inferior aspect of the labral tear. Once the anchor is inserted and the sutures are passed, the labrum will be secured back to the glenoid. Traditionally, the sutures are then tied down securely with an arthroscopic knot. Some newer techniques allow for knotless fixation to the glenoid.
Fixation then moves up the glenoid with additional anchors and sutures until the anteroinferior labrum is re-secured to the glenoid. Anchor placement should be close enough to ensure a strong repair but not so close that subsequent anchors/sutures threaten previous fixation. Usually a minimum of two and a maximum of 4 to five anchors are necessary. Thinking of the glenoid as a clock face, a rough guide is to space anchors no more than an hour apart on the clock face. The anterosuperior labrum typically does not need repair as it either isn’t torn or is a normal variant if not secured to the glenoid.
Once the Bankart lesion is repaired, it should be stable on the glenoid to the arthroscopic probe. The humeral head should be centered on the glenoid. If a “drive through” sign was present at the beginning of the case, it should be eliminated once the repair is complete. Inspection of the shoulder with the scope in an anterior portal should visualize that the labral repair recreates an anteroinferior bumper along the glenoid with a visible anterior band of the inferior glenohumeral ligament.
If there is a concomitant rotator cuff tear, it should be repaired using the appropriate surgical technique, most often arthroscopic.
Once the case is completed, the arthroscopic equipment is removed and the portals are closed. After a sterile surgical dressing is applied, patients are typically placed in an immobilizer. There are varying reports in the literature on the optimal position for immobilization with most placing the patient in neutral or internal rotation.
Pearls and Pitfalls of Technique
Facilitate procedure with portal placement for optimal approach to the labral tear and glenoid
Reduce the humeral head while securing the labrum back to the glenoid
Carefully assess the rotator cuff for concomitant injury, helpful to check the subacromial space
Assess patients over 40 for associated fractures and rotator cuff tears after a dislocation
Glenoid bone loss may be present in recurrent dislocators, although this is less frequent in patients over 40.
Bone quality may be poor in older patients
Early mobilization is essential to minimize the risk for stiffness
Outcomes may not be as good as for patients under 40.
The biggest concern in patients over 40 is stiffness, with or without surgical intervention. Patients should be mobilized relatively early compared to younger patients. The recurrence rate for instability is much lower than in younger patients. Perioperative risks include cerebral hypotension (particularly if surgery is performed in the beach chair position), infection, nerve injury (typically secondary to anchor placement or traction if surgery is performed in the lateral decubitus position), and deep vein thrombosis (DVT). Patients can have recurrence after surgical intervention and chondrolysis is another rare risk, unless intra-articular pain pumps are used.
After an initial anterior dislocation, patients should be placed immobilized with no weight-bearing. Bracing in external rotation may have some benefit over sling immobilization. This patient population should be mobilized relatively early because they are at higher risk of stiffness after this injury and procedure. Pendulums and protected motion should start almost immediately. The sling should be discontinued within a week, advancing protected range of motion as tolerated within a few weeks.
After surgery, the upper extremity should be immobilized and non-weight-bearing. Pendulums can start within a few days. InitiaI immobilization should be discontinued within 4-6 weeks although weight-bearing may be protected for up to 2-3 months, particularly in patients with concomitant rotator cuff repairs. As motion improves, static strengthening and scapular retraining should commence. More aggressive strengthening around the shoulder should be the final component of rehabilitation, particularly if a concomitant rotator cuff repair is performed.
Outcomes/Evidence in the Literature
Emond, M, Le Sage, N, Lavoie, A, Rochette, L. “Clinical factors predicting fractures associated with an anterior shoulder dislocation”. Acad Emerg Med. vol. 11. 2004. pp. 853-8. (Age over 40 was the strongest predictor of risk of fracture-dislocation in patients over 40 presenting to the emergency room with an anterior shoulder dislocation.)
Gomberawalla, MM, Sekiya, JK. “Rotator Cuff Tear and Glenohumeral Instability: A Systematic Review”. Clin Orthop Relat Res. vol. 17. 2013. (This systematic review demonstrated that patients with persistent pain and dysfunction after a shoulder dislocation should have prompt evaluation of the rotator cuff.)
Imhoff, AB, Ansah, P, Tischer, T, Reiter, C, Bartl, C, Hench, M, Spang, JT, Vogt, S. “Arthroscopic repair of anterior-inferior glenohumeral instability using a portal at the 5:30-o’clock position: analysis of the effects of age, fixation method, and concomitant shoulder injury on surgical outcomes”. Am J Sports Med. vol. 38. 2010. pp. 1795-803. (In patients treated with arthroscopic stabilization via a 5:30 portal for anterior shoulder instability, younger age was a predictor of recurrent instability. Concomitant rotator cuff tear was not associated with a higher rate of recurrence.)
López-Hualda, A, Marín-Aguado, MA, Valencia-García, H, López-González, D, Gavín-González, C. “Glenohumeral instability in patients over 40 years-old: Injuries, treatment and complications”. Rev Esp Cir Ortop Traumatol. 2013. (Patients undergoing arthroscopic stabilization of glenohumeral instability over the age of 40 were 7.3 times more likely to have associated rotator cuff tears (81%) than patients under the age of 40. There was no difference between the two populations in the rate of labral injury, Hill-Sachs lesions, bony Bankart injury, neurologic injuries, or post-operative complications.)
Maier, M, Geiger, EV, Ilius, C, Frank, J, Marzi, I. “Midterm results after operatively stabilised shoulder dislocations in elderly patients”. Int Orthop. vol. 33. 2009. pp. 719-23. (This study compared outcomes after anterior shoulder dislocation between patients under the age of 40 and those over the age of 40. Patients under 40 had a greater number of previous dislocations and were more likely to have proximal humerus fractures. Patients over the age of 40 have worse outcomes than the younger patients in terms of adjusted Constant score, Rowe score, DASH score, and visual analogue scale (VAS).)
Paterson, WH, Throckmorton, TW, Koester, M, Azar, FM, Kuhn, JE. “Position and duration of immobilization after primary anterior shoulder dislocation: a systematic review and meta-analysis of the literature”. J Bone Joint Surg Am. vol. 92. 2010. pp. 2924-33. (This systematic review reported that age less than 30 was associated with a higher risk of recurrence of anterior instability. Immobilization typically is not necessary for more than a week and bracing in external rotation may have some benefit over immobilization in a sling but more study is needed.)
Voos, JE, Livermore, RW, Feeley, BT, Altchek, DW, Williams, RJ, Warren, RF, Cordasco, FA, Allen, AA. “HSS Sports Medicine Service. Prospective evaluation of arthroscopic bankart repairs for anterior instability”. Am J Sports Med. vol. 38. 2010. pp. 302-7. (In this cohort study with 83 patients ranging in age from 15 to 55, age under 25 was associated with a much higher risk of recurrent instability.)
Patients over the age of 40 are at risk for shoulder dislocations, although the incidence is less than for young adults and adolescents. There is an elevated risk for associated rotator cuff injury in these patients. Since recurrent instability is much lower than in younger patients, initial treatment is usually non-operative, except with a concomitant traumatic rotator cuff tear or displaced fracture. Surgical treatment typically consists of an arthroscopic stabilization. Stiffness can occur with operative or non-operative treatment so early mobilization is recommended.
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