– Written by Eugene Ng and James Linklater, Australia

UNDERSTANDING COMMON SPORTING INJURIES OF THE UPPER LIMB

The world of sports comes with its fair share of risks, particularly to the upper limbs. From rotator cuff tears to biceps tendon injuries, each ailment tells a story of high-impact activity, repetitive strain or both. Let’s explore these common injuries, their imaging techniques and what makes them so unique in the world of athletics.

SHOULDER INJURIES: FROM ROTATOR CUFF TEARS TO INSTABILITY

Rotator Cuff Injuries

Rotator cuff injuries are common in sports involving overhead motions, like tennis or baseball. They range from mild contusions to complete tears. The most common pattern of injury involves partial-thickness tears, particularly on the articular side of the supraspinatus tendon. These injuries often occur at the junction of the supraspinatus and infraspinatus attachments to the humerus (Figures 1 and 2).

Associated MRI Findings:

• Partial-thickness tears appear as focal discontinuity or high signal intensity on T2-weighted or proton density (PD) fat-saturated images¹.
• Full-thickness tears exhibit tendon retraction, a fluid-filled gap with muscle atrophy or fatty infiltration in chronic cases¹.
• ABER positioning enhances visualization of labral injuries and intra-tendinous tears² (Figures 3 and 4).

Anterior Glenohumeral Instability

Anterior glenohumeral instability, the most common type, often results from traumatic dislocation or repetitive overuse. Injuries typically involve the anterior labrum, capsule, and glenohumeral ligaments.

Associated MRI Findings:

• Bankart lesions (labral detachment) appear as labral contour irregularities and high signal on fluid-sensitive sequences³.
• Hill-Sachs lesions present as bone marrow edema or a cortical defect on the posterolateral humeral head.
• Capsular laxity or thickening of the inferior glenohumeral ligament complex is often seen³.
• MR arthrography enhances detection of subtle labral and ligamentous tears⁴ (Figure 5).

Traumatic Posterior Instability

Posterior instability, although less common, occurs from posterior dislocation, often due to a fall or repetitive posteriorly directed forces. Common patterns include labral tears and humeral head impaction fractures.

Associated MRI Findings:

• Reverse Bankart lesions demonstrate posteroinferior labral detachments with high signal on fluid-sensitive sequences⁵.
• Reverse Hill-Sachs lesions show cortical defects or marrow oedema in the anteromedial humeral head.
• Posterior capsular thickening and posterior labral irregularities are typical findings.
• Glenoid hypoplasia or retroversion may predispose patients to posterior instability⁶ (Figure 6).

Acromioclavicular Joint Injury

Acromioclavicular (AC) joint injuries are common in contact sports such as football and rugby. The most frequent injury pattern involves disruption of the AC and coracoclavicular ligaments, often graded using the Rockwood classification.

Associated MRI Findings:

• Ligamentous disruption appears as fibre discontinuity with high T2 signal intensity.
• Joint capsule swelling and fluid signal in acute injuries.
• Chronic injuries may show hypertrophic changes, joint widening, or ossification.
• Associated findings include bone marrow edema or periosteal stripping^7-8 (Figure 7).

Pectoralis Major Tears

Pectoralis major tears are most common in young, active men and often occur during eccentric contraction, such as during bench press exercises. The most common muscular injury is a tear of the inferior sternal head muscle fibers. The myotendinous junction is the second most common location for tears and occurs more frequently in those older than 30 years of age. Tendon tears most commonly occur at the humeral insertion. The classification system developed by El Maraghy and Deveraux is the most commonly classification used to describe tears of the pectoralis major muscle^9-10.

Associated MRI Findings:

• Complete tears show tendon retraction with a fluid-filled gap and adjacent hematoma.
• Partial tears present as increased intramuscular fluid-sensitive signal with tendon thickening or focal fibre disruption.
• Chronic injuries may demonstrate muscle atrophy and fatty infiltration (Figure 8).

ELBOW INJURIES: UNDER PRESSURE

Elbow dislocation

Ulnar collateral ligament (UCL) injury is most common with radial collateral ligament (RCL) and lateral ulnar collateral ligament injury frequently observed. Common flexor and extensor tendon injury is common with involvement of the biceps, brachialis and triceps tendons seen less commonly¹¹.

Associated MRI findings:

Ligamentous and tendon injury presents as high signal or fibre discontinuity

Associated joint effusion

Avulsion fractures (Figure 9)

Ulnar Collateral Ligament (UCL) Tears

Pitchers beware! The most common pattern of UCL injury involves partial tears of the anterior bundle, the primary restraint to valgus stress during throwing. These tears are often located proximally at the humeral attachment^12-13.

Associated MRI Findings:

High T2 signal and fibre disruption in the anterior bundle

Oedema and fluid tracking along the ligament

Bone marrow oedema or stress reaction in the medial epicondyle in chronic cases

Overuse Syndromes

Repetitive stress isn’t kind to the elbow. Conditions like medial epicondylitis (“golfer’s elbow”) or lateral epicondylitis (“tennis elbow”) are common. The most typical pattern of injury is degeneration and partial tearing of the common flexor or extensor tendon origins^14-15.

Associated MRI Findings:

• Thickened tendons with intermediate T1 and hyperintense T2 signal.
• Adjacent soft-tissue and bone marrow oedema.
• Partial tears show fibre discontinuity and fluid-sensitive signal in the tendon.

WRIST AND HAND: SMALL JOINTS, BIG PROBLEMS

Scaphoid Fractures

These fractures account for 70% of all carpal injuries, often occurring after a fall on an outstretched hand. The most common pattern involves fractures at the waist of the scaphoid, a region with limited blood supply that predisposes it to non-union^16-17.

Associated MRI Findings:

• Bone marrow oedema visualized on fat-saturated T2 or STIR sequences.
• Disruption of cortical bone continuity.
• Subtle fractures often appear as linear low-signal intensity on T1-weighted images.

Ligamentous injuries

The scapholunate ligament complex plays a key role in wrist stability and is composed of three anatomic segments. The dorsal band is the strongest ligament and plays a key role in wrist stability with the volar band and intermediate bands mostly contributing to a weaker fibrocartilaginous component.

Other important ligaments are the extrinsic ligaments with the most important comprising the  palmar radioscaphocapitate, radiolunotriquetral ligaments and the dorsal intercarpal ligament (also known as the scaphotriquetral ligament), which serve to stabilize the wrist in the extremes of motion (secondary stabilizers). Dorsal intercalated segment instability develops when the secondary stabilizers which include the radioscaphocapitate and radiolunotriquetral ligaments and dorsal intercarpal/scaphotriquetral ligament) are involved^18-19 (Figure 10).

Associated MRI findings:

• Complete ligament tears present as disruption of the ligament with fluid signal and communication between the radiocarpal and midcarpal joints.
• Partial tears demonstrate the presence of fluid in a small defect of the ligament and partial deformation. 

Intersection Syndrome

Intersection syndrome occurs due to friction at the crossing of the first and second extensor compartments of the wrist, common in rowers and weightlifters^20-21.

Associated MRI Findings:

• Peritendinous edema and thickening of the extensor carpi radialis brevis and longus tendons.
• Fluid-sensitive sequences show hyperintensity at the tendon intersection site.
• Adjacent soft-tissue inflammation is common.

Extensor Carpi Ulnaris (ECU) Tendon Injury and Subsheath Injury

ECU injuries, including subsheath injuries, frequently affect racket sport athletes due to repetitive wrist supination^22-23

Associated MRI Findings:

• ECU tendon subluxation or dislocation with surrounding fluid-sensitive signal changes.
• Subsheath disruptions appear as high T2 signal with fibre discontinuity in the extensor retinaculum.
• Tendinosis shows tendon thickening and signal heterogeneity.

Impaction Syndromes

Wrist impaction syndromes, including ulnar impaction, occur from repetitive axial loading^24-25.

Associated MRI Findings:

• Subchondral bone marrow edema in the ulnar head and lunate.
• Tearing or degeneration of the triangular fibrocartilage complex (TFCC).
• Joint space narrowing or sclerosis in chronic cases.

Triangular Fibrocartilage Complex (TFCC) Injuries

Traumatic injuries of the TFCC often result from a forced axial load on the wrist in an extension-pronation position, such as a fall on an outstretched hand. These injuries may also occur from distraction forces applied to the volar forearm or wrist, commonly seen in racket sports. The TFCC plays a critical role as a stabilizer of the distal radioulnar joint (DRUJ) and functions as a shock absorber for the carpus²⁴.

The TFCC consists of several components: the articular disc, dorsal and volar radioulnar ligaments, meniscus homologue, extensor carpi ulnaris tendon sheath, and ulnocarpal ligaments. Among these, the dorsal and volar radioulnar ligaments are particularly significant for evaluation, as their tears are more likely to cause DRUJ instability. These ligament tears, due to their vascularity, are more amenable to surgical repair than central tears^26-27 (Figure 11).

Imaging Findings

• Normal Appearance: On MRI, the TFCC typically demonstrates low signal intensity across all imaging sequences.
• Pseudo-Lesions: Areas of increased signal intensity may be present near the ulnar insertion due to loose connective tissue and at the radial insertion due to the interface with normal articular cartilage, which can mimic a tear.
• Traumatic Tears: These tears often show fluid in the DRUJ, bony avulsions, and abnormal high signal intensity within the TFC on fluid-sensitive sequences.
• Advanced Techniques: MR arthrography enhances visualization of subtle tears, particularly in complex or partial injuries.

Extensor Tendon and Sagittal Band Injuries

Extensor tendon and sagittal band injuries often occur from direct trauma or forceful extension^28-29.

Associated MRI Findings:

• Partial tears show discontinuity and high signal intensity within the tendon.
• Sagittal band disruptions present as hyperintensity and thickening adjacent to the metacarpal head.
• Surrounding soft-tissue oedema and hematoma may also be seen

Flexor Digitorum Profundus (FDP) Injuries

FDP tendon injuries, including “jersey finger,” occur from forced hyperextension of a flexed finger^30-31 (Figure 12).

Associated MRI Findings:

• Tendon retraction with surrounding T2 hyperintensity.
• Fluid-sensitive sequences highlight partial or complete discontinuity.
• Associated volar plate or bony avulsion fractures may be present.

Imaging: The Backbone of Diagnosis

Imaging is pivotal in diagnosing and managing upper limb injuries. MRI has revolutionized sports medicine, offering non-invasive yet precise insights into injuries and remains the gold standard for many conditions due to its unparalleled ability to visualize soft tissue, bone marrow and complex joint structures and often plays a role in monitoring recovery, assessing healing tissue and guiding return-to-play decisions (Figure 13).

Eugene Ng M.D., FRANZCR 

James Linklater M.D., MBBS(Hons), B.MedSc, FRANZCR

Castlereagh Imaging

St Leonards

Sydney, Australia

Contact: linklj@bigpond.com

References

1. Koganti DV, et al. Role of Magnetic Resonance Imaging in the Evaluation of Rotator Cuff Tears. Cureus. 2022;14(5):e25262.
2. Huang T, et al. Diagnostic Accuracy of MRA and MRI for Partial-Thickness Rotator Cuff Tears: A Meta-Analysis. J Orthop Surg Res. 2019;14(1):250.
3. Sgroi TA, et al. MRI Evaluation of Glenohumeral Instability in Athletes. Curr Sports Med Rep. 2020;19(2):84-89.
4. Shah N. Advanced Imaging in Anterior Shoulder Instability. AJR Am J Roentgenol. 2018;210(5):1066-1075.
5. Provencher MT, et al. Posterior Shoulder Instability: Diagnosis and Management. Sports Health. 2017;9(4):362-372.
6. Ruiz Santiago F, et al. Posterior Glenohumeral Instability Imaging: What Radiologists Should Know. Radiol Clin N Am. 2019;57(5):937-949.
7. Antonio GE, et al. MR Imaging Appearance and Classification of Acromioclavicular Joint Injury. AJR Am J Roentgenol. 2020;214(2):347-355.
8. Gregory BT, et al. Advances in Imaging of the Shoulder in Athletic Injuries. Clin Radiol. 2021;76(4):289.e1-289.e10.
9. Chadwick N, et al. High-Resolution MRI in Pectoralis Major Injuries: A Systematic Review. J Ultrasonography. 2023;23(92):134-141.
10. Lee YK, et al. MRI and Ultrasound in Pectoralis Major Tears: Diagnostic Accuracy and Imaging Features. RSNA Radiol J. 2019;48(6):789-797.
11. Demino C, Fowler JR. Magnetic Resonance Imaging Findings After Elbow Dislocation: A Descriptive Study. Hand (N Y). 2022;17(4):730–3.
12. Nakanishi K, et al. MR Arthrography of the Elbow: Evaluation of the Ulnar Collateral Ligament. Skeletal Radiol. 2016;45(6):819-830.
13. Kheterpal AB, et al. Overuse Injuries of the Elbow. Radiol Clin N Am. 2019;57(5):865-878.
14. Husarik DB, et al. Elbow Nerves: MR Findings in Asymptomatic Subjects. Radiology. 2019;291(1):182-189.
15. Bucknor MD, et al. Elbow Imaging in Sport: Sports Imaging Series. Radiology. 2016;278(3):662-674.
16. Karl JW, et al. Diagnosis of Occult Scaphoid Fractures: A Cost-Effectiveness Analysis. J Bone Joint Surg. 2015;97(3):186-196.
17. Patel NK, et al. MRI in Occult Scaphoid Fractures: A Cost-Effectiveness Study. Emerg Med J. 2019;36(1):26-30.
18. Eladawi S, et al. 3T MRI of wrist ligaments and TFCC using true plane oblique 3D T2 Dual Echo Steady State (DESS) - a study of diagnostic accuracy. Br J Radiol. 2022;95(1132):20210949.
19. Crockenpot E, et al. Imaging of sports-related hand and wrist injury. RSNA Radiology Revies and Commentary. 2016;10(3):45-52.
20. Yin Z, et al. MRI of Wrist Overuse Syndromes: A Focus on Intersection Syndrome. Skeletal Radiol. 2020;49(4):577-589.
21. Chhabra A, et al. Wrist Imaging in Sports Medicine. Curr Sports Med Rep. 2019;18(2):52-59.
22. Leung Y, et al. MRI of Extensor Carpi Ulnaris Disorders in Athletes. Radiol Rep. 2021;8(3):145-152.
23. Bolster M, et al. ECU Tendon Imaging Advances. J Musculoskelet Med. 2023;12(1):34-41.
24. Shah S, et al. MRI of Wrist Impaction Syndromes: An Update. Radiol Clin N Am. 2019;57(5):861-873.
25. Wong TT, et al. Advances in MRI Diagnosis of TFCC Injuries: A Focus on Subtle Lesions. J Wrist Surg. 2021;10(2):101-111.
26. Patel K, et al. High-Resolution MRI in Triangular Fibrocartilage Complex Tears: Diagnostic Accuracy and Surgical Implications. Radiology Reports. 2023;12(4):789-798.
27. Lee JH, et al. Imaging of TFCC Disorders: State-of-the-Art Techniques. Skeletal Radiol. 2022;51(6):919-933.
28. Zheng Q, et al. MRI of Hand Extensor Mechanisms in Athletes. Skeletal Radiol. 2020;49(5):657-668.
29. Martin M, et al. Advances in Extensor Tendon Imaging. Radiology Updates. 2018;45(2):89-97.
30. Lambert J, et al. MRI Features of Flexor Tendon Injuries in Athletes. J Wrist Imaging. 2022;7(3):341-348.
31. Wong A, et al. High-Resolution Imaging of Flexor Tendons. Radiol Sports. 2020;16(4):251-259.

Header by Doha Stadium Plus Qatar (Cropped)