Extensor Carpi Ulnaris Tendinopathy in Athletes: A Review of the Conservative and Rehabilitative Options

Abstract

Background:

Extensor carpi ulnaris (ECU) tendinopathy is characterized by pain along the dorsal and ulnar aspect of the wrist and distal forearm. It is common in athletes who play stick and racquet sports due to repetitive motion and axial-loading through the wrist and forearm. Conservative therapeutic options include rest, the use of anti-inflammatory medications, and various injections. Rehabilitation via occupational or physical therapy includes therapeutic exercise, splinting, activity modification, manual therapy, and modalities.

Methods:

A narrative review of the literature on ECU tendinopathy is presented, and a case study approach is used to highlight the clinical management of this condition in an elite athlete.

Results:

An approach of medical management and rehabilitation allowed this patient to successfully return to play.

Conclusions:

A combination of conservative measures and rehabilitation can be used to treat ECU tendinopathy and permit patients to be symptom-free and return to their desired activities.

Introduction

Extensor carpi ulnaris (ECU) tendinopathy is characterized by pain along the dorsal and ulnar aspect of the wrist and distal forearm. Anatomically, the ECU originates from the lateral epicondyle of the humerus, then passes along the dorsal aspect of the ulnar shaft and styloid process, and inserts on the dorsal ulnar base of the fifth metacarpal. ¹ The tendon passes through the sixth dorsal extensor compartment of the wrist, and the muscle belly is innervated by posterior interosseous nerve, a motor nerve branch of the radial nerve. ¹ Functionally, the ECU is responsible for ulnar deviation in forearm pronation and wrist extension in forearm supination, as well as a supporting structure for dynamic stabilization of the distal radioulnar joint (DRUJ) as it traverses the joint.^{1 -3}

The ECU tendon has its own subsheath, which assists in securing the tendon in the ulnar groove. ⁴ This subsheath is a component of the triangular fibrocartilage complex (TFCC), which comprises volar and dorsal radioulnar ligaments, ulnocarpal ligaments, the ECU tendon subsheath, the lunotriquetral interosseous ligament, and the articular disk. The TFCC, a stabilizer of the ulnar wrist, provides soft tissue and ligamentous stability to the DRUJ and ulnar carpal bones.^1,5 Injuries to the ECU can occur in conjunction with other structures, such as the TFCC, or independently. ⁶ Given its anatomical makeup and contribution to function, injury to the TFCC may impact ECU tendon function and DRUJ stability. ² The distal ulna comprises 20% of the axial load of the forearm; therefore, disruption of the TFCC compromises the stability of the distal ulna, which in turn reduces the force transmitted through the distal ulna and may affect the function and performance of the ECU tendon. ⁵ In a study by Tang et al, ⁵ rupture of the TFCC demonstrated increased excursion and bowstringing of the ECU tendon, indicating that the TFCC is important to ECU tendon stability and serves as a pulley for the tendon. Care should be taken to review the differential diagnoses for ECU tendinopathy and rule in or out injury to the TFCC and/or DRUJ. ² Although the etiology of ECU tendinopathy is unclear, mechanisms involving tendon overload, compression, and inflammation have been proposed.^{7 -9} Extensor carpi ulnaris tendinopathy is a common source of pain and dysfunction in athletes who perform repetitive “snapping” motions and axial-loading of the forearm and wrist.^2,6 The ECU is susceptible to injury, instability, and tendinopathy, when the forearm encounters an unexpected rotational force with twisting motions, such as the combination of hypersupination and wrist flexion motions, as seen in stick sports. ⁶ Repetitive forearm rotation may also stress the ECU subsheath, predisposing it to injury. ¹⁰ This may cause attenuation or rupture of the ECU subsheath and subsequent subluxation or dislocation of the tendon out of the ECU groove.^1,4,11,12 Furthermore, ECU tendinopathy can also be seen in nonathletes who perform repetitive ulnar deviation and wrist extension, as well as in patients with rheumatoid arthritis.

The purpose of this review is to present the most common conservative and rehabilitation intervention techniques during the treatment of athletes with ECU tendinopathy.

Case Example

JS is a 20-year-old male faceoff specialist on a university men’s lacrosse team who presented to an orthopedic sports medicine physician who was part of a division 1, National Collegiate Athletic Association athletic training room. The patient reported a 6-month history of ulnar wrist pain dating back to the previous season. At the time of presentation, he was unable to tolerate faceoff training and had pain with lifting his textbooks and backpack, typing for greater than 15 minutes, and turning doorknobs. Physical examination findings included bilateral pain with palpation over the ECU tendon just distal to the ulnar styloid along with pain and weakness with resisted wrist extension and ulnar deviation (graded 4/5 with manual muscle testing). Based on these findings, he was diagnosed with bilateral ECU tendinopathy by the team physician.

The team physician subsequently ordered bilateral wrist and hand radiographs, which were normal. Magnetic resonance imaging of both wrists and hands was then performed and demonstrated tendinopathic changes about the mid-substance of the ECU tendon at the level of the ulnar styloid process (Figure 1). No other abnormalities were present on advanced imaging. Upon further consultation with a hand surgeon, JS received bilateral platelet-rich plasma (PRP) injections into each ECU tendon and surrounding subsheath due to the chronicity of the condition and timing of the upcoming season. The injections were performed without ultrasound guidance. JS was subsequently referred to therapy 6 days post injection for a rehabilitation and return-to-play program.

Figure 1.

T2 magnetic resonance imaging of the left wrist of JS. (a) Sagittal view: note the intratendinous signal change of the extensor carpi ulnaris. (b) Coronal view: note the intrasubstance signal abnormality within the extensor carpi ulnaris tendon.

Source. Courtesy of Dr Joshua M. Abzug, MD.

A progressive loading approach was developed based on concepts previously published.^8,13 Exercises focused on the capacity of the athlete’s wrist and forearm muscles using isometric, progressive resistance and eccentric strengthening. Grip strength and related upper quarter muscle groups above and below the wrist were addressed as well. Specific attention was paid to loading of the ECU musculotendinous unit with resisted wrist extension and ulnar deviation exercises with dumbbells. Exercises such as modified planks on a DynaDisc and controlled wrist movements with balance perturbations were included to reintroduce upper extremity weight-bearing and proprioception. Medicine ball throws in multiple angles of wrist flexion and radial deviation were used to build his tolerance for the faceoff and rate of force development. A return-to-play process was developed in collaboration with his physicians, athletic trainer, strength and conditioning coach, and lacrosse coaches. The process was based on structured increases in volume and intensity of faceoff drills. At the completion of 6 weeks of therapy, JS was able to return to full, unrestricted strength and conditioning participation and lacrosse practice. He completed the season without reporting any recurrence of symptoms.

Discussion

The physical examination should include an assessment of tendon integrity. Evaluating for ECU tendon rupture, instability, and tendinopathy is important to guide management. Palpation along the ulnar side of the wrist between the ulnar styloid and the fifth metacarpal base with the forearm in pronation and active ulnar deviation will allow access to the ECU tendon. ⁶ Patients will often report ulnar-sided wrist pain with wrist and forearm activity. ⁶ Pain in the ulnar wrist is often increased when resisting ulnar deviation and wrist extension motions, or with passive stretches in radial deviation and wrist flexion. ⁶ Significant weakness may also suggest full thickness rupture. Instability can be assessed with both passive and active motion while palpating for subluxation of the ECU tendon. With the wrist in extension and forearm in supination, the wrist is transitioned into flexion and ulnar deviation. Instability of the ECU tendon will cause volar subluxation with possible snapping. ⁶ A provocative maneuver to assess for ECU instability is the Ice Cream Scoop Test, which is performed with the patient’s wrist in pronation, ulnar deviation, and extension. ¹⁴ The examiner palpates the ECU tendon and instructs the patient to perform a scooping motion by moving the forearm into supination while maintaining ulnar deviation against the examiner’s resistance. A positive test will produce ECU tendon snapping over the distal ulna with pain. ¹⁴ Tendinopathy can also be elicited with pain provocation during resisted wrist extension and ulnar deviation.

Imaging may be helpful to further assess the ECU tendon and consider differential diagnoses. Magnetic resonance imaging may be useful to evaluate tendon pathology and delineate pathology in the subsheath and/or TFCC (Figure 1). Ultrasound may also be used to evaluate the ECU tendon structure in a dynamic fashion.

Nonoperative Management

Nonoperative management of ECU tendinopathy typically consists of a trial of rest and nonsteroidal anti-inflammatory medications. In addition to these treatments, rehabilitation is incorporated early on to resolve symptoms associated with the diagnosis. Patients who do not experience substantial relief with the first line of treatments noted above may benefit from additional interventions such as a corticosteroid injection into the sixth dorsal extensor compartment. The utilization of ultrasound may aid in accurate placement of the injection. Investigational interventions should a corticosteroid injection fail or not be a viable option include emerging treatments such as PRP injections and/or acupuncture. Platelet-rich plasma injections are proposed to initiate a healing cascade but have questionable efficacy in upper extremity conditions, and specific usage has not been reported in ECU pathology. ¹⁵ Acupuncture is proposed to stimulate meridians identified in Chinese medicine, which may play a role in physical health. Current evidence for use of acupuncture in upper extremity conditions is also questionable with no available literature on ECU pathology. ¹⁶ Additional research for both of these treatment options is needed to determine whether there is truly efficacy or not.

Physical and Occupational Therapy

A period of immobilization is often implemented with short-arm casting or a wrist orthosis to limit movement. ¹² A short-arm cast may be beneficial for patients who are highly active and may not be compliant with orthosis wear. Splinting the wrist in 30° of extension and slight ulnar deviation is optimal. ⁴ Some providers may elect to limit forearm supination by placing the patient in a custom-fabricated muenster brace positioned with the forearm in neutral alignment or pronation.^11,10 An orthosis is typically used for 4 to 6 weeks; however, this time period may differ based on patient progress and the severity of injury.^{10 -12}

Following the immobilization period, the patient may begin a progressive program to achieve pain reduction, regain range of motion and strength, and return to their desired activities such as sports participation. Therapeutic exercise is critical to improve function of the musculotendinous unit. ⁸ Pain-free active range of motion (AROM) should be promoted to the patient’s tolerance. Once full symmetric AROM is achieved, progressive strengthening should be initiated when symptom irritability is well controlled. Specific exercises to target the ECU should be prioritized. ¹³ Examples include wrist extension and ulnar deviation against progressive resistance from dumb bells (Figure 2); exercises to challenge proprioception and dynamic stability during gripping, lifting, reaching, twisting, and carrying; and upper extremity weight-bearing tasks. ¹³ Upon initiation of the weight-bearing and strengthening program, a wrist widget may be used to provide support and stability to the ulnar aspect of the wrist as well as to unload it. ¹⁰

Figure 2.

Ending position for (a) wrist extension, (b) supination, (c) pronation, and (d) ulnar deviation.

Source. Courtesy of Dr Michael Zarro, PT, DPT, SCS, CSCS.

In addition to splinting and exercise, modalities are typically used by therapists to assist with symptom reduction and to allow the patient to increase functional use of the injured extremity. Modalities have varying levels of efficacy. Clinicians should consider the evidence and use of modalities in the context of a comprehensive treatment strategy. In the treatment of ECU tendinopathy, modalities that may be incorporated include ultrasound, iontophoresis, myofascial cupping, and/or dry needling.

Therapeutic ultrasound is a treatment modality that has both tissue healing and tissue heating effects, determined by the parameters used and implication for treatment.^{17 -19} In the case of ECU tendinopathy, ultrasound may be used to address the soft tissue inflammation associated with injury. To address the inflammatory response, parameters for ultrasound include 50% pulsed, 3.3 MHz, and 1.5 W/cm² for approximately 6 to 7 minutes in duration. ¹⁹

Iontophoresis is a modality used to deliver anti-inflammatory medication transdermally. ¹⁷ In the treatment of ECU tendinopathy, dexamethasone, an anti-inflammatory corticosteroid medication, is used to decrease pain in the wrist extensors, thereby allowing increased active motion and functional use of the extremity. ¹⁸

Myofascial cupping is a technique that applies traction to superficial skin, fascia, and muscle by removing air from glass or plastic cups placed on the skin. It is proposed to improve circulation and generate a metabolic healing response. Static cupping, which is placing the cups over the affected tissue, or dynamic cupping, which is moving the cups over the affected tissue, may be used to target the ECU musculotendinous unit. ²⁰

Dry needling is a minimally invasive technique where a monofilament needle is inserted to stimulate tendon, fascial, and/or muscle tissue to reduce pain and stimulate recovery. Targeted dry needling with pistoning or in situ technique of the ECU muscle belly or tendon may be indicated to address symptoms. ²¹

Return to sport or other functional activity should follow a stepwise approach. ⁸ A period of activity modification may be indicated to allow symptoms to reduce to manageable levels. Patients should be educated to remain active but avoid activities that specifically provoke symptoms, such as repetitive ulnar deviation or loading of the ulnar wrist. Examples include repetitive mouse use with computer activities or gripping with twisting that provokes pain. As symptoms subside, a return to play process should be initiated. This should include activities to prepare the musculotendinous unit for the demands of sport. Examples include medicine ball throwing and dynamic stabilization in positions that mimic sporting postures/positions (Figure 3).^4,8,13

Figure 3.

Dynamic stabilization drills using (a) TheraBand FlexBar, (b) ball flips, (c) DynaDisc, and (d) marbles.

Source. Courtesy of Dr Michael Zarro, PT, DPT, SCS, CSCS.

Interval sport programs may be used to progress activity and have been published for baseball, tennis, and golf. ²² A gradual accumulation of training load should also be advocated to allow the tissues to accommodate to stress. ²³ Return to sport should be viewed as a continuum with many contributing factors, such as restoration of physical, mental, and overall health; safe return to sport-specific training; and compliance with ethical and regulatory bodies.

Summary

A variety of conservative and rehabilitative approaches may be used during the treatment of ECU tendinopathy in athletes. These methods rely on a careful examination and consideration of the differential diagnosis of the ulnar-sided wrist pain. A combination of medical management, modalities, therapeutic exercise, and a graded return-to-sport program should be performed when treating ECU tendinopathy.