Introduction
Overuse injuries result from cumulative trauma or many repetitive minor insults, such that the body does not have adequate time to heal properly. These types of injuries typically occur in low-contact sports that require long training sessions and repetitive loading (e.g., running, jumping, rowing, and swimming) and can lead to loss of playing time, physiologic exhaustion, and pain. Overuse injuries typically present with a gradual onset of pain, masking the true severity of the injury. Yang et al. conducted a study evaluating acute and chronic injuries in professional athletes and reported that male athletes have higher rates of acute injuries than their female counterparts, but female athletes had higher rates of chronic overuse injuries. Previous studies have supported the findings that female athletes have an increased risk of overuse injuries than male athletes. Female rowers reported a significantly greater number of chest overuse injuries and female military recruits reported more stress fractures than male rowers and recruits, respectively. , Magnusson et al. evaluated differences in the adaptability of tendons to loading between females and males and demonstrated that females have an attenuated tendon hypertrophy response to habitual training, a lower tendon collagen synthesis rate following acute exercise, further attenuation of collagen synthesis based on levels of estrogen, and lower mechanical strength in their tendons. Therefore female athletes may be at an increased risk for developing symptoms of tendonitis. The increase in female athletic involvement increases the risk for the development of overuse injuries. Therefore it is important to identify and properly manage these types of injuries in order to allow athletes to return to sport and prevent progression to more serious sequelae.
Achilles Tendon Injuries
Achilles tendon pain is common among athletes and can be related to several conditions including tendinopathy, tendinosis, tendinitis, tenosynovitis, and rupture. Maffulli et al. described tendinopathy as a combination of tendon pain, swelling, and impaired performance, with peritendinitis and tendinosis found on histopathology. Acute tendonitis is defined by the presence of symptoms for less than 2 weeks, while symptoms lasting for more than 6 weeks are classified as chronic tendonitis. The Achilles tendon comprises the distal insertion of the gastrocnemius-soleus musculotendinous unit transmitting loads to the calcaneus in order to plantarflex the foot. There is a relative zone of avascularity approximately 2–6 cm proximal to the tendon insertion, and therefore this area is at greatest risk for degeneration and rupture.
Risk Factors
Achilles tendinopathy is most prevalent in athletes participating in middle- and long-distance running, tennis, volleyball, and soccer, with an incidence rate up to 9% of all top-level runners. , Biomechanical analyses have demonstrated that malalignment within the foot and ankle may predispose to Achilles tendon injuries. Kvist et al. demonstrated that limited mobility of the ankle and subtalar joint may contribute to increased risk of injury. Muscle imbalance and decreased flexibility can lead to a loss of protection of the tendon during increased physical activity and load-bearing exercises.
Presentation/Examination Findings
Patients presenting with Achilles tendon injuries typically recall a change in activity levels that led to either an insidious or a gradual onset of discomfort over the Achilles tendon. The patient usually describes relief of symptoms with rest, but pain returns as soon as the patient resumes activity. Achilles tendon rupture often occurs acutely, with patients describing a “pop”. On physical examination, there is usually a palpable defect over the area of ruptured tendon. Squeezing the calf in the prone position (i.e., Thompson test) does not elicit movement of the foot and can confirm diagnosis of rupture.
Imaging
Ultrasound is useful in providing information regarding changes of water content within the tendon as well as collagen integrity. Abnormal tendons usually demonstrate a larger tendon diameter with higher levels of water content and collagen discontinuity, and tendon sheath swelling. Although ultrasound is useful, magnetic resonance imaging (MRI) remains the study of choice for diagnosing Achilles tendon injuries ( Fig. 21.1 ).
Treatment
Initial management of Achilles tendinopathy includes activity modification, physical therapy, and antiinflammatory medications. Niesen-Vertommen et al. reported that eccentric training was superior to concentric training in reducing pain in chronic Achilles tendinopathy. Deep friction massage accompanied by stretching is utilized to restore elasticity and reduce muscle-tendon strain. It has been reported that 24%–45% of patients with Achilles tendon injuries fail conservative management, ultimately requiring surgical intervention. , Surgical treatments include open versus percutaneous Achilles tenotomy for tendinopathy and tendon repair for rupture ( Fig. 21.2A–C ). Testa et al. evaluated 52 male and female elite middle- and long-distance runners with Achilles tendinopathy and reported good functional outcomes following percutaneous longitudinal tenotomies. Postoperatively, patients are often immobilized for 2 weeks and then transitioned to a CAM (controlled ankle motion) boot where they may begin ankle range of motion. Patients are often non-weight-bearing for as long as 6–8 weeks following repair.
Patellar Tendinopathy/Tendonitis
Patellar tendinopathy, also referred to as “jumpers knee”, is common in athletes involved in repetitive jumping, climbing, kicking, or running as a result of excessive pain over the patella tendon. Repetitive motion of the extensor mechanism results in focal degeneration leading to fraying and microtearing of the tendon. ,
Risk Factors
Patellar tendon injuries typically affect athletes involved in sports including basketball, volleyball, football, soccer, high/long jump, tennis, and running. Torstensen et al. demonstrated that elite athletes are more often affected than recreational athletes. Van der Worp et al. conducted a meta-analysis reviewing risk factors for developing patellar tendinitis. The authors found that body mass index, waist-to-hip ratio, leg-length difference, arch height of foot, quadriceps/hamstring flexibility, quadriceps strength, and vertical jump all influence loading of the patellar tendon. In addition, several factors related to training can contribute to the development of patellar tendinopathy/tendinitis, including quick acceleration, deceleration, stopping, and cutting actions.
Presentation/Examination Findings
Athletes typically present with an insidious onset of pain that is related to the frequency and intensity of their training. Initially, pain presents as a dull ache on the anterior aspect of the knee just inferior to the patella. Patients often state that the pain is worse when walking or running upstairs and downstairs. The key finding is tenderness to palpation over the patellar tendon, which is usually worse in extension.
Imaging
Ultrasound and MRI are imaging modalities often utilized to confirm the diagnosis of patellar tendinopathy. Ultrasound can identify decreased echogenicity and irregularities within the tendinous envelope. MRI can also demonstrate areas of higher signal intensity in the affected regions of the tendon.
Treatment
Nonoperative intervention is the first line of treatment in patients with patellar tendinitis. Activity modification, antiinflammatory medication, and physical therapy are initially recommended. Rest is important in the early phases of recovery. Rehabilitation progresses from controlled exercises without load, to eccentric and concentric load, and finally to return to sports. Other methods to reduce the load on the tendon include orthotics, braces, and straps. The Cho-Pat strap is commonly utilized to support the tibial attachment of the patellar tendon. Most athletes will be successfully treated with conservative measures alone.
Patellar tendon surgery is typically reserved for patients who have failed at least 6 months of conservative therapy. Surgical interventions include drilling of the inferior pole of the patella, resection of the tibial attachment of the patellar tendon, repair of defects, tenotomy/tenoplasty, percutaneous needling, and excision of the inferior pole of the patella with repair. Ferretti et al. reported excellent results in 70% of male and female amateur and professional athletes with a mean age of 27 years treated with longitudinal splitting of the tendon and drilling of the inferior pole of the patella. Cucurulo et al. evaluated arthroscopic procedures in the treatment of patellar tendonitis in athletes, which involved controlled shaving of retrotendinous tissue and excision of damaged tendon. This study demonstrated good results in motivated athletes and reported equivalent outcomes in both open and arthroscopic techniques.
Rotator Cuff Tendonitis
Rotator cuff tendonitis is often used as a general term for athletes experiencing shoulder pain without a full-thickness rotator cuff tear or another identifiable cause for the pain. Rotator cuff tendonitis can often lead to tendinosis (i.e., degeneration of the tendon) and tear. The rotator cuff is composed of four muscles, namely, supraspinatus, infraspinatus, teres minor, and subscapularis, with all arising from the scapula. These four muscles combine to provide dynamic stability to the glenohumeral joint.
Risk Factors
Rotator cuff injuries are usually the result of overuse in athletes and rarely occur following a single traumatic event. Motions including overhead throwing, serving in tennis, and spiking the ball in volleyball increase the rotational forces on the shoulder during acceleration and deceleration phases and lead to an increased risk of injury. Athletes with anterior glenohumeral instability have an increased risk of developing rotator cuff tendonitis, as there is increased stress across the rotator cuff with this condition. Impingement syndrome has been implicated as an underlying cause of multiple athletic shoulder injuries including rotator cuff tendonitis. External impingement occurs when the rotator cuff is compressed between the greater tuberosity and the acromion. Internal impingement occurs when the infraspinatus is compressed between the humeral head and the posterior superior glenoid rim with the arm in maximal external rotation as seen in overhead throwing athletes.
Presentation/Examination Findings
The typical presentation of rotator cuff tendonitis is pain with overhead activity. Athletes typically note increased discomfort during maximal abduction and external rotation or during follow-through, when the rotator cuff is placed on maximal strain and tension. , Athletes initially describe discomfort during the painful activity that decreases with rest. Special tests can help isolate individual muscles of the rotator cuff. The empty can test and the drop arm test isolate the supraspinatus and may give positive results with rotator cuff tendonitis. The infraspinatus can be tested by external rotation, with the arm at the athlete’s side. Patients with injuries affecting the teres minor may show external rotation weakness at 90 degrees of abduction with 90 degrees of external rotation (i.e., Hornblower’s sign). The lower subscapularis is tested using the belly press, while the upper aspect of the subscapularis is tested using the bear hug test. Other tests that may be beneficial in assessing an athlete with shoulder pain include Speed’s test for biceps tendon pathology, O’Brien’s test for labral pathology, and the apprehension test for glenohumeral instability.
Imaging
Imaging studies for rotator cuff tendonitis should always begin with shoulder radiography including a Grashey view (true anteroposterior [AP] of the shoulder), scapular Y, and axillary lateral view. Superior migration of the humeral head may be found after rotator cuff tears; however, normal radiographs are common in athletes with rotator cuff tendonitis. Other modalities available include ultrasound to visualize the rotator cuff. It is less useful in cases of rotator cuff tendonitis; however, it can detect degeneration of the rotator cuff. MRI is the imaging modality of choice, as it provides much more detail of the soft tissue, rotator cuff tendons, and any fatty atrophy that occurs within the supraspinatus and other rotator cuff muscles.
Treatment
Initial treatment includes a short duration of rest (3–5 days) combined with nonsteroidal antiinflammatory drugs (NSAIDs). A physical therapy program should be implemented focusing on stretching and strengthening of the shoulder girdle with emphasis on scapula stabilization and proper muscle activation during the athlete’s specific sport. In addition, subacromial corticosteroid injections may be beneficial by reducing pain and inflammation.
Surgical intervention is rarely utilized for rotator cuff tendonitis in the athletic population and is typically reserved for patients who have failed conservative management. Depending on the symptoms and imaging findings, surgical options include subacromial decompression, rotator cuff debridement, and rotator cuff repair (arthroscopic or mini-open technique). Surgical intervention is warranted in full-thickness tears of the rotator cuff, bursal sided tears >3 mm, and partial articular supraspinatus tendon avulsion lesions >7 mm or involving >50% of the tendon. Athletes requiring surgical intervention have also shown good results. Reynolds et al. evaluated 82 active male professional baseball pitchers who underwent arthroscopic debridement of a partial thickness rotator cuff tear and demonstrated that up to 76% were able to return to competitive pitching; however, only 50% returned to the same or higher level of competition. A systematic review by Klouche et al. evaluated return to sport in patients (all ages, participating in all sports at a variety of levels) with partial or full-thickness rotator cuff tears. This study demonstrated an overall return to sport of 84.7% following rotator cuff repair. Of those athletes, 65% were able to return to their previous level of play and only 49% were able to return to their previous level of play in the professional and competitive athlete population.
Biceps Tendonitis
Biceps tendonitis is an overuse injury often seen in overhead athletes due to the increased demands on the biceps tendon as it traverses through the narrow bicipital groove. Continued painful activity without rest can lead to tendinosis or degeneration of the biceps tendon. Biceps tendonitis typically occurs concomitantly with other shoulder injuries such as rotator cuff tendonitis/tears, subacromial impingement, superior labral tear from anterior to posterior (SLAP) tears, bursitis, and glenohumeral instability. ,
Risk Factors
Overhead throwing athletes are at an increased risk of developing biceps tendonitis. Laudner and Sipes reported a 12.1% incidence of biceps tendonitis in collegiate overhead throwing athletes. The authors demonstrated that biceps tendonitis was most commonly reported in swimming, baseball, softball, tennis, and volleyball. Oliver et al. evaluated muscle activation patterns during windmill softball pitching and found the biceps brachii is most active during the acceleration phase of the pitch. Another possible risk factor for injury to the biceps tendon occurs with amateur athletes. Amateur throwing athletes have shown greater activity to the biceps during the acceleration and deceleration phases than their professional counterparts, whereas professional athletes demonstrate more efficient recruitment of rotator cuff muscles.
Presentation/Examination Findings
Athletes with biceps tendonitis often complain of anterior shoulder pain; however, diagnosing biceps tendonitis versus other shoulder pathologies may be difficult, given the overlapping symptoms. Typically, biceps tendonitis occurs in conjunction with other pathologies within the shoulder; however, isolated pathology to the long head of the biceps tendon can occur in the younger and more athletic population. Early signs of biceps tendonitis include pain after activity, with more severe presentations causing pain during activity and at rest. An audible snap or popping sensation in the anterior shoulder may signify subluxation of the biceps tendon. The two physical examination tests most commonly utilized in the diagnosis of biceps tendonitis are the Speed’s test and Yergason’s test. Speed’s test is performed by resisted forward flexion of the shoulder to 90 degrees with the elbow fully extended and the forearm supinated. A positive test result is defined by pain within the bicipital groove. Yergason’s test is performed with the elbow at 90 degrees of flexion and the shoulder in neutral position. A positive test result is when pain is localized within the bicipital groove while undergoing resisted supination.
Imaging
Initial imaging studies include standard shoulder radiography (i.e., Grashey, scapular Y, and axillary lateral views), which are typically normal. In addition, a magnetic resonance arthrogram may provide useful information regarding inflammation surrounding the biceps tendon. MRI provides information regarding soft tissue pathology surrounding the shoulder. However, it is poor at detecting biceps tendinopathy, having a concordance rate of only 37% with arthroscopy.
Treatment
Initial treatment involves a period of rest combined with a multimodal approach including NSAIDs, activity modification, physical therapy, and corticosteroid injections. The sheath of the long head of the biceps is continuous with the glenohumeral synovium; therefore corticosteroid injections in the subacromial space (for patients also presenting with impingement syndrome) and glenohumeral joint can help decrease inflammation surrounding the biceps tendon within the bicipital groove.
Surgical management is reserved for cases of biceps tendonitis who have failed nonoperative treatment as well as other more concerning issues with the long head of the biceps, such as partial tear of the biceps tendon (>25%), medial subluxation of the biceps tendon, subluxation in the setting of a subscapularis tendon tear, and SLAP tears. In addition, visualizing an inflamed biceps tendon intraoperatively may prompt a decision to manage the biceps surgically. Management of pathology of the long head of the biceps tendon involves either tenotomy or tenodesis. Both procedures may be performed either as open or arthroscopically depending on the experience and comfort level of the practicing surgeon. There is still no consensus as to which surgical option provides the best outcomes for the patient. In a systematic review and meta-analysis comparing biceps tenotomy and tenodesis, the authors found no difference between open or arthroscopic biceps tenodesis with regard to functional outcome. They did note that patients who received a tenotomy were more likely to develop a Popeye deformity and cramping in the bicipital groove, which is consistent with previous literature.
There is limited research regarding outcomes of athletes undergoing surgical management of biceps tendonitis. This is likely because the majority of athletes improve following conservative management. Therefore activity modification, physical therapy, and antiinflammatory medication should be implemented as the first-line treatment for biceps tendonitis.
Lateral Epicondylitis
Lateral epicondylitis, also known as “tennis elbow”, typically occurs in the fourth or fifth decades of life, but it can be found in patients ranging from 12 to 80 years old. It is most commonly thought of as an overuse injury in relation to athletes and nonathletes playing tennis, although it can affect any athlete or worker whose occupation requires repetitive wrist extension activities. About 50% of all tennis players will have lateral epicondylitis at least once in their career. The greatest muscle activity during a ground stroke is found in the wrist extensors, more specifically the extensor carpi radialis brevis (ECRB), extensor carpi radialis longus, and the extensor digitorum communis. Most notably, the ECRB demonstrates the greatest muscle activity and was most prominent during the acceleration and early follow-through phases. The repetitive stress on the ECRB leads to small tears in the tendon, resulting in an influx of fibroblasts with disorganization of parallel collagen and vascular hyperplasia. Nirschl described the microscopic appearance as “angiofibroblastic hyperplasia” and found the tendon to have varying amounts of grayish, homogenous, edematous, and friable tissue.
Risk Factors
Tennis players are at greatest risk for developing lateral epicondylitis. The incidence and prevalence increase in patients over the age of 40 years, underscoring an overuse, degenerative process. Other risk factors include improper technique, poor equipment selection, and the type of tennis court being used. Studies have demonstrated that inexperienced players are more prone to have improper swinging mechanics and therefore greater mechanical stress at the elbow. , Grip size, racquet weight, racquet string tension, and the number of strings may also have an effect on how much force is transmitted through the hand and into the wrist extensors, thereby predisposing athletes to pain over the lateral epicondyle.
Presentation/Examination Findings
Lateral epicondylitis typically presents as lateral elbow pain that may or may not radiate down the forearm. A history of repetitive activities that involve wrist extension is typical of these athletes. Patients often present with an insidious onset, reporting gradual worsening of symptoms. Other complaints include decreased grip strength, difficulty picking up objects, and increased pain with activities that involve wrist extension. On physical examination, patients will demonstrate tenderness to palpation over the ECRB tendon just distal and slightly anterior to lateral epicondyle. Reproducible pain will be noted with resisted wrist extension that is often increased with the elbow in full extension. In addition, patients exhibit pain with resisted long finger extension as well as passive wrist flexion with the forearm in pronation.
Imaging
Initial imaging should include standard AP and lateral radiography of the elbow. The radiographs are typically normal in patients with lateral epicondylitis, but they can be helpful in ruling out other causes of lateral elbow pain. Ultrasound is a useful diagnostic tool for lateral epicondylitis. MRI can be used to evaluate for pathology associated with lateral epicondylitis, but it is not often necessary for the diagnosis ( Fig. 21.3 ).
