AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

The ulnar collateral ligament (UCL) of the elbow is critical for valgus stability of the elbow and is the primary elbow stabilizer.^{1, 2} As such, the UCL plays an important role in most throwing sports, including baseball and javelin, as well as racquet sports and ice hockey.

Elbow injuries in young athletes are generally chronic, with persistent pain and instability from repetitive overhead activities. In the athlete, ligamentous injury can also be heralded by an acute traumatic event such as an elbow dislocation. This can then lead to chronic pain and valgus instability. An understanding of the anatomy and biomechanics of the elbow in throwing sports is essential to the correct diagnosis and treatment of this potentially disabling injury.³

Functional Anatomy

The UCL originates at the posterior distal aspect of the medial epicondyle and inserts into the base of the coronoid process. At 90º of flexion, it provides 55% of the resistance to valgus stress at the elbow. In full extension, the UCL, bony architecture, and anterior capsule equally maintain valgus stability.

The UCL is composed of 3 bands: anterior, posterior, and transverse. The anterior band, which arises from the anteroinferior surface of the medial epicondyle and inserts on the sublime tubercle of the ulna, provides the major contribution to valgus stability.

Sport-Specific Biomechanics

The acceleration phase of the overhead throw causes the greatest amount of valgus stress to the elbow.⁴ Extension occurs at a rate of up to 2500º per second and continues to 20º of flexion. During this phase, the forearm lags behind the upper arm and generates valgus stress while the elbow is primarily dependent on the anterior band of the UCL for stability. During the acceleration phase, valgus stress can exceed 60 Newton meters (Nm), which is significantly higher than the measured strength of the UCL in cadavers. The valgus force can, therefore, overcome the tensile strength of the UCL and cause either chronic microscopic tears or acute rupture.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Medial elbow pain is the most common symptom in athletes who throw. Pain may be especially prominent during the acceleration phase of the overhead throw.
• Pain is often chronic or recurrent, and it may lead to a slow erosion of the patient's throwing ability.
• Athletes may report having had similar pain in previous seasons of throwing.
• Rest generally helps to relieve the pain.
• Occasionally, during a single throw, athletes may experience acute pain over the medial elbow, sometimes associated with a popping sensation, that causes them to immediately stop throwing.

Physical

• Medial elbow tenderness and swelling are the most notable findings. Tenderness is commonly found approximately 2 cm distal to the medial epicondyle. UCL tenderness may occasionally be difficult to differentiate from flexor pronator tendinitis, but the pain of flexor pronator tendinitis is aggravated by resisting forearm pronation.
• Loss of elbow range of motion (ROM) is occasionally observed.
• With acute rupture, ecchymosis may be observed over the medial elbow.
• Pain may be reproduced when the patient makes a clenched fist.
• Valgus stress with the elbow in 25° of flexion (elbow abduction stress test) reproduces pain and may cause joint opening. The affected side should be compared with the contralateral elbow as a reference for baseline laxity.
• Some throwing athletes have a baseline asymmetry; therefore, preseason documentation of baseline elbow laxity in elite athletes, especially pitchers, may be helpful for comparison if an injury occurs during the season.

Causes

• Repetitive throwing motions are the most common cause of UCL injury in the athlete.
• Traumatic valgus stress to the elbow during a fall or with the arm outstretched may lead to UCL rupture in association with elbow dislocation.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to Be Considered

Flexor pronator muscle tear/tendinitis
Ulnar neuritis/ulnar nerve entrapment
Medial epicondylar fracture
Valgus extension overload

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Laboratory studies are not indicated during the workup of UCL injuries.

Imaging Studies

• Radiography
• • Findings from routine radiography can occasionally be diagnostic if an avulsion fragment is seen, and in a minority of patients, this study can also reveal secondary findings that are suggestive of UCL injury, such as ossification of the ligament. Plain radiographs are also helpful to rule out other causes of elbow pain, such as epitrochlear osteophytes, epicondylar fractures, posterior olecranon fossa loose bodies, ligamentous calcification, or capitellar lesions.⁵
  • Manual or instrumented valgus stress radiography can be used to document increased joint opening and ligamentous laxity. Significant asymmetry may be observed in traumatic elbow injuries such as dislocations, whereas laxity in a throwing athlete may not be so obvious, with only a very subtle asymmetry.
  • Gravity stress radiography—with the patient supine, the shoulder in maximal external rotation, and the weight of the forearm resisted by the UCL—may also be helpful.⁶
• Plain arthrography: This imaging modality is not indicated because dye leak has been shown to be inconsistent in cases of chronic laxity, and only an acute event may be anticipated to exhibit a positive finding.
• Magnetic resonance imaging (MRI): MRI with contrast, as with all soft-tissue injuries, is rapidly becoming the imaging study of choice to document ligamentous rupture; however, because of the relatively small size of the UCL and the failure of dye leakage in chronic injury,⁷ even MRI may generate false-negative results.
• Dynamic ultrasonography: This modality may be helpful in the evaluation of ligamentous laxity in throwing athletes; however, studies of this modality for acute injuries are lacking.⁸
• Computed tomography scanning (CT) with intra-articular contrast: This technique has been studied in small numbers of patients. CT scanning with intra-articular contrast appears to be highly sensitive and specific for both acute and chronic injuries,⁷ but more data are needed before widespread use can be recommended.

Procedures

• Arthroscopy is believed by some authors to be the most specific diagnostic procedure because it allows visualization of the medial compartment while valgus stress is applied; however, clinical suspicion of a UCL injury via a good history and physical examination is probably the most reliable in making the diagnosis.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Acute Phase

Rehabilitation Program

Physical Therapy

Generally, 3-6 months of conservative therapy with rest, nonsteroidal anti-inflammatory drugs (NSAIDs), and local physical therapy for ROM are necessary for recovery.

Recreational Therapy

When pain and swelling completely resolve and the athlete has returned to a premorbid ROM (usually not before 3 months of treatment), progressive return to activity with increasing velocity and duration of training may be attempted.

Medical Issues/Complications

Surgery may be considered in several situations. Surgical repair is generally indicated for acute tears in competitive athletes, when chronic instability exists, and when the patient has recurring pain and laxity after 2 or more attempts at conservative therapy.

Surgical Intervention

Direct repair of the ligament is generally not indicated. Reconstruction of the UCL (eg, repair of the anterior bundle) is the more common approach to surgical treatment, with use of a palmaris longus tendon autograft. The graft is pulled through bone tunnels in the medial epicondyle of the humerus and the sublime tubercle of the ulna in a figure-8 pattern. Ulnar nerve transposition may be undertaken at the time of surgery, if indicated.

Consultations

Consultation with an orthopedic surgeon, preferably a sports or upper-extremity specialist, is indicated when surgical intervention is contemplated.

Other Treatment

Steroid injection is not recommended for UCL injuries.

Recovery Phase

Rehabilitation Program

Physical Therapy

After surgery, the elbow is immobilized in a posterior splint for 10 days in 90° of flexion. The wrist is maintained free, and a soft rubber ball is given to the patient for squeezing to maintain grip strength. Active ROM is initiated after removal of the posterior splint. A hinged brace that prevents valgus stress should be used.

At approximately 1 month after surgery, isometric strengthening exercises should be initiated. Limited progressive strengthening can be initiated at 8 weeks and plyometrics at 12 weeks. Shoulder and elbow exercises should be instituted as soon as feasible, but valgus stress of the elbow should be avoided for at least 4-6 months until the graft has had sufficient time to incorporate.

Recreational Therapy

After 4-6 months, throwing may be resumed with a training program that is designed to return the patient to competitive throwing by 9-12 months after surgery.

Medical Issues/Complications

Both transient and permanent ulnar neuropathy may occur after reconstruction, occasionally requiring ulnar nerve transposition or revision of transposition. Flexion contracture (generally <5°) may also occur in 25-30% of patients.

Surgical Intervention

Ulnar nerve transposition (or revision of transposition) may be required for persistent postoperative ulnar neuropathy.

Maintenance Phase

Rehabilitation Program

Physical Therapy

Flexibility and strength training of the elbow are useful in the maintenance phase to prevent recurrent injury.

Recreational Therapy

During the maintenance phase, particular attention to the patient's throwing technique is essential to prevent recurrence of injury.

Medical Issues/Complications

Long-term complications may include chronic pain with throwing and chronic instability of the elbow.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

NSAIDs are the cornerstone of therapy for the control of pain that is associated with UCL injuries.

Drug Category: Analgesics

Pain control is essential to patient care.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Return to Play

Competition may be resumed when the following criteria are met:

• The athlete is pain free with throwing.
• Elbow and shoulder ROM has returned to within normal limits.
• Forearm strength has returned to baseline.
• Good throwing biomechanics have been established.

Complications

• Ulnar nerve injury or entrapment may occur.
• Chronic instability is possible.

Prevention

Injuries to the UCL are best prevented by ensuring proper throwing biomechanics. Coaches are essential to assessing the proper throwing techniques in the athlete. Thorough warm-up and flexibility exercises also play an essential role in preventing UCL injuries.

Prognosis

Return to competitive throwing by the patient is possible after successful rehabilitation and reconstruction, when indicated.

Education

Proper throwing technique is essential to preventing UCL injuries; therefore, athlete education is critical. Analysis of the athlete's throwing technique and constructive criticism by coaches may be helpful.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to consider UCL injury despite negative radiographic findings
• Failure to refer patients with suspected complete UCL tears

Special Concerns

• Pediatric patients, because of immaturity of their elbows, may experience an avulsion injury of the medial epicondyle due to tensile loads of the valgus elbow. The lateral elbow undergoes corresponding compressive loads that could result in problems such as osteochondritis dissecans or Panner disease of the capitellum.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

1. Hechtman KS, Tjin-A-Tsoi EW, Zvijac JE, Uribe JW, Latta LL. Biomechanics of a less invasive procedure for reconstruction of the ulnar collateral ligament of the elbow. Am J Sports Med. Sep-Oct 1998;26(5):620-4. [Medline].
2. Lee ML, Rosenwasser MP. Chronic elbow instability. Orthop Clin North Am. Jan 1999;30(1):81-9. [Medline].
3. Maloney MD, Mohr KJ, el Attrache NS. Elbow injuries in the throwing athlete. Difficult diagnoses and surgical complications. Clin Sports Med. Oct 1999;18(4):795-809. [Medline].
4. Fleisig GS, Andrews JR, Dillman CJ, Escamilla RF. Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med. Mar-Apr 1995;23(2):233-9. [Medline].
5. Safran MR. Ulnar collateral ligament injury in the overhead athlete: diagnosis and treatment. Clin Sports Med. Oct 2004;23(4):643-63, x. [Medline].
6. Rijke AM, Goitz HT, McCue FC, Andrews JR, Berr SS. Stress radiography of the medial elbow ligaments. Radiology. Apr 1994;191(1):213-6. [Medline]. [Full Text].
7. Timmerman LA, Schwartz ML, Andrews JR. Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med. Jan-Feb 1994;22(1):26-31; discussion 32. [Medline].
8. Sasaki J, Takahara M, Ogino T, et al. Ultrasonographic assessment of the ulnar collateral ligament and medial elbow laxity in college baseball players. J Bone Joint Surg Am. Apr 2002;84-A(4):525-31. [Medline].
9. Curl LA. Return to sport following elbow surgery. Clin Sports Med. Jul 2004;23(3):353-66, viii. [Medline].
10. Darlis NA, Kaufmann RW, Sotereanos DG. Open surgical treatment of post-traumatic elbow contractures in adolescent patients. J Shoulder Elbow Surg. Nov-Dec 2006;15(6):709-15. [Medline].
11. Dines JS, Elattrache NS, Conway JE, Smith W, Ahmad CS. Clinical outcomes of the DANE TJ technique to treat ulnar collateral ligament insufficiency of the elbow. Am J Sports Med. Aug 16 2007;epub ahead of print. [Medline].
12. Gibson BW, Webner D, Huffman GR, Sennett BJ. Ulnar collateral ligament reconstruction in major league baseball pitchers. Am J Sports Med. Apr 2007;35(4):575-81. [Medline].
13. Grana WA, Boscardin JB, Schneider HJ, et al. Evaluation of elbow and shoulder problems in professional baseball pitchers. Am J Orthop. Jun 2007;36(6):308-13. [Medline].
14. Halpern BC. Elbow and arm injuries. In: Birrer RB, ed. Sports Medicine for the Primary Care Physician. 2^nd ed. Boca Raton, Fla: CRC Press; 1994:435-41.
15. Hyman J, Breazeale NM, Altchek DW. Valgus instability of the elbow in athletes. Clin Sports Med. Jan 2001;20(1):25-45, viii. [Medline].
16. Jobe FW, Conway JE, Bradley JP. Ulnar neuritis and medial elbow instability. Curr Ther Sports Med. 1995;118-23.
17. Morrey BF, Regan WD. Throwing injuries. In: DeLee JC, Drez D Jr, Miller MD, eds. Delee & Drez's Orthopaedic Sports Medicine: Principles and Practice. Philadelphia, Pa: WB Saunders Co; 1994:882-3.
18. Purcell DB, Matava MJ, Wright RW. Ulnar collateral ligament reconstruction: a systematic review. Clin Orthop Relat Res. Feb 2007;455:72-7. [Medline].

Article Last Updated: Sep 26, 2007