Shoulder unstable and elbow (copy)

Unstable Shoulder and Tennis Elbow

This lecture focuses on the concepts of shoulder instability, the mechanics surrounding it, and a brief overview of tennis elbow. A number of recommended resources and other learning materials are available, which overlap with material presented on Blackboard, particularly as students prepare for upcoming assessments.

Unstable Shoulder

Definition and Overview

An unstable shoulder refers to the inability of the humeral head to remain centered in the glenoid cavity, contrasting with frozen shoulder, which involves limited mobility and stiffness. It is important to note that having an unstable shoulder does not automatically imply the shoulder is dislocating; it indicates a failure of the control system that stabilizes the humeral head, primarily under load. Symptoms may occur at rest or more commonly under load.

Causes of Unstable Shoulder

  1. Traumatic Causes:

    • Often associated with clear injury mechanisms such as dislocation or subluxation.

    • Usually, these involve structural damage to ligaments, capsules, or surrounding structures.

  2. Atraumatic Causes:

    • Develop gradually without a specific traumatic episode.

    • May result from poor motor control or generalized laxity, often observed in individuals participating in high-activity sports.

    • Patients may present with recurring issues from past injuries, where injury prevention and control have failed.

Mechanisms of Injury

  • Most injuries occur during abduction and external rotation of the shoulder.

  • Injuries may result from both contact and non-contact incidents, though contact is more typical.

Symptoms

  • Symptoms of shoulder instability include:

    • Apprehension when moving the shoulder in certain positions.

    • Feeling that the shoulder is not adequately seated in its joint, potentially leading to a sensation of “giving way.”

    • Occasional sensations of a “dead arm.”

    • General loss of confidence in performing activities involving the shoulder.

    • Pain may be evident, but instability is often the primary presentation rather than pain on its own.

Demographics

  • Unstable shoulders tend to frequently occur in younger patients; traditionally, this has been more prevalent in males participating in collision sports such as rugby and AFL.

  • An increasing number of females are also being affected due to their rising participation in these sports.

  • Atraumatic instability frequently occurs in younger females, particularly those with hypermobility issues.

  • Overhead sports, like tennis, can also contribute to micro-instability due to repetitive overloaded mechanics.

Terminology

  • Laxity refers to the degree of asymptomatic translation of the humeral head from the center of the glenoid.

  • Instability, on the other hand, indicates abnormal symptomatic motion of the shoulder, often accompanied by pain or subluxation.

    • Subluxation is defined as a partial or temporary displacement of the humeral head from the center of the glenoid, often described by patients as feeling as if it “came out but went back in.”

    • Dislocation denotes a complete separation of the glenohumeral surfaces that may necessitate external assistance to reduce.

  • Both laxity and instability can coexist, though laxity may predispose an individual toward instability.

Stanmore Classification

The Stanmore classification establishes that shoulder instability exists on a spectrum with various types characterized by different underlying causes:

  • Polar Type 1: Traumatic, unilateral instability with structural damage but normal muscle patterning.

  • Polar Type 2: Atraumatic with structural damage, presenting gradual capsular laxity without a singular traumatic event.

  • Polar Type 3: Characterized by abnormal muscle patterning, typically in younger individuals with poor neuromuscular control and may experience significant anxiety around movement.

Patients can move between these types over time, with rehabilitation strategies aimed at moving them toward stability.

Traumatic Structural Instability

  • The most common cause of shoulder instability is dislocation due to traumatic injuries, predominantly occurring anteriorly (up to 90%).

  • Such dislocations typically result from forced abduction and external rotation of the shoulder.

  • Potential associated injuries include Bankart lesions, which involve damage to the anterior labrum, and Hill-Sachs lesions resulting from compressive fractures of the humeral head.

Labrum and Labral Injuries

  • Labrum: A ring of fibrous tissue that enhances the stability of the glenoid cavity and provides proprioceptive feedback to the shoulder joint. Its damage can lead to joint instability and further affect the shoulder's stabilizing structures.

  • Surgical Considerations: Surgery may be warranted, especially in young athletes with recurrent shoulder dislocations, to repair damaged structures such as the labrum. Two primary procedures are:

    • Bankart Repair: Involves reattaching the torn labrum to the bone of the glenoid.

    • Latarjet Procedure: A more invasive option transferring the coracoid process to prevent further dislocations by adding a mechanical block to anterior movement.

SLAP Tears

  • SLAP Tear: Refers to Superior Labrum Anterior to Posterior tear, involving the region where the long head of the biceps tendon attaches.

  • These tears can be either traumatic (e.g., due to dislocation or fall) or degenerative, and are often asymptomatic or produce vague symptoms.

  • SLAP tears can be classified into types from degenerative fraying to complete detachment of the biceps anchor (most clinically relevant).

  • Surgical intervention varies based on types and severity, with less favorable outcomes seen particularly in older patients.

Atraumatic Multidirectional Instability

  • Generally characterized by instability in multiple directions without a clear traumatic cause, often requiring gradual muscle strengthening and control rehabilitation. Symptoms:

    • Scapular positioning abnormalities, such as downward rotation and poor upward rotation during arm elevation, leading to decreased joint stability.

    • Symptoms include apprehension, impingement, and neuropathic symptoms.

Rehabilitation Strategies

  • Rehabilitation approaches change based on the type of instability experienced.

    • TUBS (Traumatic Unidirectional Bankart) requires surgical intervention and promotes stable rehabilitation post-surgery.

    • AIOS (Atraumatic Instability with Overuse Syndrome) requires focused training on scapular and rotator cuff control.

    • MDI (Multidirectional Instability) necessitates rehabilitation targeting neuromuscular control and ensuring proper positioning of the scapula during movement.

Watson Rehabilitation Program

  • This program specifically addresses MDI through control exercises rather than strength alone, emphasizing upward scapular rotation and humeral head centering in closed-chain positions. The progression of exercises is dictated by quality and control rather than merely resistance levels.

Tennis Elbow

Overview

Tennis elbow, or lateral epicondylitis, is characterized by gradually developing pain and tenderness around the lateral epicondyle of the elbow, commonly provoked by gripping and repetitive wrist extension movements.

Assessment

  1. History and Symptoms: Understanding insidious onset and activity-related aggravation is key.

  2. Palpation: Confirmation of local tenderness can aid in diagnosis.

  3. Grip Strength: Measuring pain-free grip strength is an essential objective measure for managing tennis elbow.

  4. Static and Dynamic Evaluations: Assessing potential proximal weaknesses in the shoulder or scapular control could indicate a need for corrective measures in rehabilitation.

Understanding Tennis Elbow

  • Evidence suggests tennis elbow is not solely a local condition, as patients often show deficiencies in upper limb strength, including:

    • Significant reductions in grip and wrist extensor strength.

    • Measurable decreases in shoulder muscle strength and endurance among scapula stabilizers.

  • Rehabilitation should thus focus both locally on the elbow and more broadly on upper limb control and strengthening to alleviate symptoms effectively.

Management Strategies

  1. Initial Conservative Approaches: Gradual reduction of aggravating activities and ergonomic adjustments while considering short-term pain management options such as NSAIDs.

  2. Strengthening Programs: Focused graduated strengthening of the wrist extensors and endurance training; stretches are only suggested if constrained movement is observed.

  3. Manual Therapy Techniques: Incorporating mobilization with movement can assist in pain-free rehabilitation as needed.

  4. Progressive Load/Exercise: Should rehabilitation display limited success, consider imaging and testing for potential additional diagnoses or exploring corticosteroid injections as a temporary relief measure.

  5. Long-term Solutions: Surgical interventions remain rare and considered a last resort after extensive conservative management has failed.

In conclusion, both unstable shoulder conditions and tennis elbow require distinct management strategies centered on understanding the mechanical, neurological, and rehabilitative aspects relevant to each patient’s presentation. Regular assessments and tailored rehabilitation strategies are essential for successful outcomes. The lecture ends with thanking the audience and encouraging participation in class discussions.