Shoulder Diagnosis and Decision Making




Because the shoulder is a complex joint that contains many anatomic structures and articulations capable of causing pain, the evaluation of a patient whose chief complaint is shoulder pain can be quite involved. The goal of a physician’s examination should be to efficiently integrate the patient’s history, physical examination findings, and diagnostic imaging results to develop an accurate diagnosis and treatment plan. All three of these diagnostic tools must be used in combination; failure to use a particular methodology may result in an improper diagnosis. This chapter examines the most common shoulder problems observed in athletes and provides selected patient history and physical examination techniques that can direct a clinician toward an accurate diagnosis. Rather than discussing history and physical examination findings associated with specific conditions, the goal is to discuss the conditions associated with particular examination findings because patients rarely arrive at the clinic with a preformed diagnosis.


Overview of Pathologies


Athletic shoulder injuries commonly encountered by clinicians include shoulder instability (traumatic or multidirectional), superior labral anterior to posterior (SLAP) lesions, shoulder impingement, rotator cuff tendinopathy/tears, and frozen shoulder (adhesive capsulitis).


Shoulder instability is a common condition encountered by clinicians. Two types of shoulder instability are observed and should be distinguished. The first type of shoulder instability is traumatic. A useful mnemonic for traumatic instability is TUBS: t raumatic, u nilateral instability involving a B ankart lesion that requires s urgery. The traumatic insult results in tearing of the labrum, which causes unidirectional instability. Lesions are usually anterior, although they may be posterior depending on the mechanism of injury.


The second type of instability is multidirectional (subluxation, dislocations, or a “loose” shoulder). A useful mnemonic for multidirectional instability is AMBRI: a traumatic, m ultidirectional, frequently b ilateral instability that responds to r ehabilitation and rarely requires i nferior capsular shift surgery. Multidirectional instability often results from overuse and is defined by generalized laxity or weakness of the glenohumeral support structures (rotator cuff). A chief complaint of “my shoulder pops out” or frequent and recurrent dislocations is evidence of multidirectional shoulder instability. If structures that surround the head of the humerus (i.e., the rotator cuff muscles and labrum) become compromised, it is possible for the head of the humerus to slide within the glenoid. Multidirectional instability can quickly progress from slight subluxation to more complete dislocation, often eliciting a feeling of apprehension in patients that the shoulder will fall out. Distinguishing subluxation events from true dislocations can be difficult. Multidirectional shoulder instability generally occurs in patients with repetitive injuries, congenital joint malformations, or major acute shoulder injuries. Younger women are at increased risk for shoulder instability because of decreased muscular development. Patients with major rotator cuff tears and athletes who use overhead motions (e.g., swimmers and throwers) are also at increased risk of shoulder instability. Multidirectional shoulder instability becomes less common as patients age because of stiffening of the shoulder’s supportive tissues. As pain leads the person to protect and favor the injured shoulder, muscle weakness resulting from inactivity exacerbates an already weakened rotator cuff, causing progression to more severe multidirectional shoulder instability.


SLAP lesions are uncommon injuries, although the rate of SLAP repairs is rapidly rising. Any person who performs repetitive overhead motions (e.g., while swimming or playing baseball, volleyball, or tennis) is at increased risk for a labral tear. SLAP lesions begin posteriorly and extend anteriorly; they stop before the midglenoid notch and include the attachment of the long head of the biceps tendon on the labrum. The most common mechanism of injury for generation of a SLAP lesion is falling onto an outstretched arm in abduction and slight flexion at impact. SLAP lesions commonly result in shoulder pain that is aggravated by raising the arm, along with a “catching” or “popping” sensation.


Shoulder impingement most frequently describes the compression of rotator cuff tendons, the subacromial bursa, and other soft tissues between the head of the humerus and the acromion. Shoulder impingement syndrome describes a multitude of clinical findings but is not representative of injury to one particular structure. Stage 1 impingement syndrome describes edema and hemorrhage, stage II describes fibrosis and tendinitis, and stage III describes rotator cuff tears, biceps tendon rupture, and bony change. Increased translation of the humerus, morphologic acromion abnormality, decreased subacromial space, and bony change in the acromioclavicular joint may all contribute to shoulder impingement syndrome. Because symptoms of shoulder impingement (i.e., pain while reaching overhead) often resemble those of rotator cuff tendinopathy, diagnosis can be difficult.


Rotator cuff tendinopathy (tendinitis or tendinosis) describes chronic injury of the rotator cuff tendons. Rotator cuff disorders frequently develop in persons who place excessive stress on the shoulder, usually as a result of repetitive overhead use of the arm. Weakness of the rotator cuff muscles may predispose a patient to shoulder instability and more dramatic rotator cuff injury. Two theories attempt to explain the development of rotator cuff tendinopathy. The intrinsic pathogenesis theory proposes that injury within the tendon from overuse and weakness may create an avascular “critical” zone in the tendon that predisposes to further injury. Eccentric contraction of rotator cuff muscles during excessive overhead use of the arm with a predisposing avascular tendon may lead to the development of intrinsic tendinopathy. The extrinsic pathogenesis theory proposes that compression of the rotator cuff tendons by extrinsic structures such as the acromion, coracoid process, or arthritic osteophytes is primarily responsible for tendinous damage.


Rotator cuff tears may develop from rotator cuff tendinopathy, but they also often develop as a result of other underlying shoulder injuries, including shoulder impingement syndrome. Rotator cuff tears most frequently develop in the supraspinatus tendon. Muscle weakness and tendon impingement in the subacromial space directly contribute to rotator cuff tears. Many tears begin as partial tears on the articular surface of the tendon but may progress to full-thickness tears that involve more rotator cuff tendons if the underlying pathology is not adequately managed. Both partial and full-thickness tears can cause pain and weakness, although patients with full-thickness tears usually have a greater degree of weakness compared with patients who have partial tears.


Frozen shoulder, or adhesive capsulitis, describes the insidious onset of limited active and passive shoulder motion concurrent with severe shoulder pain. A frozen shoulder may be primary or secondary. Patients with diabetes mellitus have a significantly increased risk of developing a frozen shoulder. Other systemic diseases (e.g., thyroid disease, autoimmune conditions, stroke, and others) have also been linked to an increased probability of developing a frozen shoulder. A frozen shoulder can also develop in patients after major shoulder injuries such as rotator cuff tears or humeral fractures or after shoulder surgeries. Although the exact pathogenesis of the disease is not fully understood, it has been proposed that inflammatory and/or fibrogenic pathways result in the development of adhesions in the synovium of the glenohumeral joint, which ultimately decreases functional joint volume and limits movement.


Having introduced five shoulder injuries commonly seen in athletes, it is useful to consider how a patient history is essential for identifying likely lesions and formulating a differential diagnosis.




History


The most important and informative aspect of the examination of a patient with shoulder pain is obtaining a detailed history directly from the patient. A complete patient history can confirm a suspected diagnosis and direct the focus of the physical examination. Without the context provided by the patient’s history, the physical examination is less useful.


When first approaching a new patient with shoulder pain, the clinician should immediately consider the patient’s age to provide a framework for subsequent questioning. If the patient is younger than 30 years, shoulder pain will more likely arise from shoulder instability as a result of overuse and athletic injury. If the patient is older than 30 years, the pain will more likely arise from rotator cuff pathology as the cuff becomes weaker with age.


After considering the patient’s age, a full patient history should be obtained. Using a standard OPQRST ( o nset, p alliation/ p rovocation, q uality, r adiation/localization, s everity, t iming) format to standardize the questions is convenient, but the exact questions asked should be those preferred by the individual clinician and should be tailored to the individual patient.


When asking about the onset of pain, it is most important to determine if the pain developed after an acute traumatic incident, after an extended period with many shoulder injuries, or insidiously. Acute painful developments may suggest shoulder instability, which is common in athletes and younger women with less-developed rotator cuffs. Acute painful developments are also possible with a history of rotator cuff tendinopathy or shoulder impingement and may represent an acute rotator cuff tear, usually of the supraspinatus. If pain develops immediately after a fall onto an outstretched arm, the examiner should consider fractures, instability as a result of muscular weakness, or labral tears as possible etiologies of the shoulder pain. If pain develops slowly without context, diabetes mellitus and other systemic conditions may be responsible and are not necessarily representative of sports-related pathology. The following sample questions can be asked while ascertaining pain onset:




  • “When did the pain start?”



  • “Have you ever had an injury to the same shoulder?”



  • “Is the injured shoulder your dominant or nondominant shoulder?”



  • “Did a particular event lead to your shoulder pain?”



  • “Do you have any systemic diseases?”



When questioning a patient about palliation/provocation of pain, it is most important to ask about joint positioning that may aggravate or alleviate symptoms. In athletes, a maneuver particular to their sport often reproduces the pain. For example, football linemen may have pain while blocking and pushing, or tennis players may have pain when executing an overhead serve. In persons with a tear of the supraspinatus tendon, a SLAP lesion, or shoulder impingement, raising the arm overhead may elicit acute pain. Additionally, pain while reaching backward may be significant for a rotator cuff tear. When shoulder instability is present, it may be uncomfortable for the patient to push in a certain direction or to push against a wall with an outstretched arm. Patients with rotator cuff tears or biceps tendon injuries may also report difficulty lifting objects, particularly overhead. Finally, it is important to ascertain any particular work or leisure activities that aggravate shoulder pain, because these activities may present a vector for repeated shoulder trauma. Sample questions to ask while ascertaining palliation/provocation of pain include “Do any particular shoulder movements cause pain?” “Do any particular activities cause more pain than others?” and “Does anything make your pain go away?”


When questioning patients about the quality of shoulder pain, it is most important to listen for key words that are correlated with certain shoulder pathologies. For instance, a sensation of “apprehension” is often significant for shoulder instability, whereas a “catching” or “popping” is often significant for SLAP lesions. Sample questions to ask while ascertaining the quality of pain include “Do you ever feel like your shoulder is about to pop out?” “Do you ever feel like your shoulder gets caught while performing normal motion?” and “How would you describe your pain?”


When questioning a patient about pain radiation, it is most important to rule out any cervical nerve impingement that may cause shoulder pain. If cervical nerve involvement is suspected, consultation with a spine specialist may be indicated, and extra care should be taken if the shoulder is manipulated. Radiation of elbow pain to the shoulder, although rare, should be considered in the context of concurrent shoulder and elbow pain. Sample questions to ask while ascertaining radiation of pain include “Do you have any numbness in your fingers?” “Do you have pain in your neck?” and “Do you have any shooting pains in your arm?”


While obtaining a patient history, it is imperative to localize pain. Asking the question, “If you had to point to the most painful part of your shoulder, what would it be?” is a particularly useful way to elicit a helpful answer. By localizing pain, one can quickly clarify glenohumeral or acromioclavicular joint pain. If the patient points to the subacromial space, supraspinatus tendinopathy or a tear may be causing the discomfort. Patients with rotator cuff pathology often report pain laterally near the deltoid attachment on the humerus. If the patient is tempted to localize pain deep within the shoulder, a SLAP lesion or adhesive capsulitis may be likely, although SLAP lesions may also present with anterolateral pain. Posterior pain in the shoulder is the least likely pain locale and is often suggestive of external rotator cuff tendinopathy or a posterior labral tear. Generalized pain near the posterior spine may be significant for a cervical spine injury. If the patient is unable to pinpoint a particular location of pain, the pain may be extrinsic to the shoulder and can suggest cervical nerve impingement.


When asking about pain severity, it is most important to determine whether the athlete feels pain only during athletic activity or if the pain is present throughout the day. Additionally, obtaining a subjective pain rating can be useful when designing a treatment protocol. Sample questions to ask while ascertaining severity of pain include “Do you ever have pain when you are not working out?” “Are you currently in pain?” and “If you had to rate your pain on a scale of 1 to 10, with 1 being almost no pain and 10 being the worst pain you’ve ever felt, what would it be?”


When asking about the timing or duration of pain, it is often useful to determine if the patient has pain while sleeping, because night pain from sleeping on the injured shoulder is correlated with rotator cuff pathology and adhesive capsulitis. Sample questions to ask when ascertaining the timing of pain include “Is the pain present at night? If so, what position makes it easiest for you to sleep?” and “Do you ever wake up because of shoulder pain?” When used properly, the physical examination can often help confirm a potential diagnosis gleaned from the patient history.




Physical Examination


The physical examination in persons with sports-related shoulder complaints is used to confirm or strengthen diagnoses suspected on the basis of the patient’s history. Without context, however, a low specificity for many manipulation procedures may limit their usefulness.


The first step in the physical examination is inspection of the shoulder. Inspection must be performed with the patient’s shirt off. There is no substitute for an astute inspection of the shoulder and comparison with the normal shoulder. Both the anterior and posterior aspects of the shoulder should be inspected, and any asymmetry should be noted. Old clavicle fractures, deltoid atrophy, skin changes, and suprapinatous/infraspinatous/teres minor atrophy can be easily appreciated through simple inspection. Muscle atrophy is a particularly important finding on inspection because it can often suggest a neurologic etiology.


After inspecting the shoulder for fractures, skin changes, and muscle atrophy, the shoulder is palpated. Palpation is particularly helpful when attempting to localize shoulder pain to a particular joint or bony component of the shoulder. For instance, tenderness over the acromioclavicular joint can indicate acromioclavicular pathology, and biceps tendon tenderness can point to biceps etiology. Any areas of tenderness should be noted. Posterior muscular tenderness can be associated with muscle spasm and/or cervical pathology. Palpation may also help confirm the diagnosis of shoulder impingement syndrome.


The next step in the physical examination of the shoulder is testing the active and passive range of motion present in the joint ( Fig. 43-1 ). For all motions, active (unaided) and passive (with assistance from the examiner) motion should be compared with the uninjured side. The ranges of motion most often examined are forward flexion, external rotation with the arm at the side, internal rotation (as measured by how high the patient can reach on the spine), abduction, isolated glenohumeral abduction, external rotation with the arm at 90 degrees of abduction, and internal rotation with arm at 90 degrees of abduction. Expected values are as follows: for forward flexion, approximately 180 degrees; for external rotation, 80 to 90 degrees; and internal rotation, approximately T5 to T8.




FIGURE 43-1


Selected range of motion manipulations. A, External rotation. B, Ninety-degree abduction and external rotation. C, Ninety-degree abduction and internal rotation. D, Internal rotation. (Not shown: forward flexion.)


During range of motion testing, the examiner should also observe movement of the scapulae. Certain shoulder pathology will exhibit abnormal scapular mechanics and/or scapular substitution that may assist in formulating a diagnosis. Shoulder dyskinesis is easily observed through scapular observation, as are medial and lateral winging. If the clinician suspects scapular winging, it can be clearly visualized during forward flexion range of motion testing and by having a patient push against a wall. If scapular winging is noted, the examiner can physically stabilize the scapula and have the patient reattempt range of motion exercises while the scapula is held in a stable position to see if this maneuver alleviates pain.


After inspection, palpation, and passive/active range of motion testing, the clinician has often confirmed the diagnosis that was suspected based on the patient’s history. Patients with shoulder instability often have full or excess motion (although motion is sometimes limited by apprehension). Patients with rotator cuff injury can have limited active motion because of muscle weakness. Adhesive capsulitis limits both active and passive motion with pain upon capsular stretch.


After testing range of motion, the clinician should assess the strength of the shoulder joint. When testing the strength of particular shoulder components, the clinician should seek to isolate individual muscles whenever possible. Rotator cuff strength is tested first through a series of shoulder manipulations with resistance. Any rotator cuff weakness or pain upon rotator cuff testing may confirm a suspected rotator cuff injury.


The “empty can” test can be used to test the strength of the supraspinatus muscle ( Fig. 43-2, A ). With the arm abducted 90 degrees in the plane of the scapula and the hand pronated with the thumb facing down, the patient attempts to further abduct the straight arm against resistance applied by the clinician. Strength can be graded and compared with the opposing, healthy shoulder. Any pain while performing the “empty can” test should be noted. Infraspinatus strength testing is performed through resisted external rotation ( Fig. 43-2, B ). With the arm at the side, the elbow is flexed to 90 degrees. The patient then attempts to externally rotate against resistance applied by the clinician. As before, strength is graded against the healthy shoulder and any pain is noted.


Feb 25, 2019 | Posted by in SPORT MEDICINE | Comments Off on Shoulder Diagnosis and Decision Making
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