Abstract
Introduction
Sports injuries represent a major concern in both professional and recreational athletes, contributing significantly to morbidity, time lost from training or competition, and long-term functional impairment, if not managed appropriately.[1] Globally, sports injuries account for about 15%–20% of annual acute-care visits.[2] Their incidence and severity vary widely depending on the nature of the sport, the athlete’s fitness level, age, and gender.
These injuries can be acute (such as fractures, ligament tears, or muscle strains) or chronic, often resulting from repetitive overuse (such as tendinopathies and bursitis).[3]
Sports injuries can be categorised in several ways:
Based on the structure involved, they may affect bones (e.g., stress fractures), joints (e.g., dislocations, labral tears), muscles (e.g., strains, tears), tendons (e.g., tendinopathies, tears), or ligaments (e.g., sprains or tears).[4] Based on the type of sport, for example:
Contact sports (e.g., football, rugby) are more likely to cause injuries, such as concussions[5] and dislocations.[4] Overhead sports (e.g., tennis, baseball) often cause shoulder impingement and rotator cuff pathology.[6] Running and jumping sports (e.g., sprinting, jumping, basketball, volleyball) are more likely associated with stress fractures,[7] ankle sprains, and patellar tendinopathy. Based on anatomical region involved, they can be divided into:
The assessment of sports injuries starts with a thorough clinical assessment. However, physical examination alone may not always provide a complete understanding of the injury, especially in elite athletes, where early and precise diagnosis is essential for the best treatment and timely return to competition. In these cases, radiological imaging plays an important role, offering valuable insights into the nature and extent of the injury and guiding treatment decisions.[1]
Imaging Techniques
Imaging plays a pivotal role in accurately diagnosing sports injuries, guiding clinical decision-making, and monitoring recovery. Selecting the most appropriate imaging modality depending on the suspected injury, the anatomical region involved, and the clinical situation is vital.[8] A combined multimodality approach is preferred in many cases to accurately diagnose and grade injuries.
Radiographs (X-ray) are the first-line imaging modality for both upper and lower limb injuries as it is quick to perform, widely available, and effective in detecting fractures and dislocations in acute injuries and periosteal reactions or degenerative changes in chronic overuse syndromes. However, X-rays have limited sensitivity for detecting early stress-related bone injuries, cartilage lesions, and most soft-tissue injuries.[9]
Ultrasonography (USG) has gained growing importance in the assessment of sports injuries due to increasing operator expertise. It is quick, easily accessible, inexpensive, with the added benefit of portability and provides excellent resolution for imaging of soft-tissue injuries, like muscle tears/hematomas,[10] tendons tears, ligaments tears and fasciitis. High-resolution ultrasound using a small footprint hockey stick probe provides a detailed evaluation of the tendons of the digits, even sometimes better than MRI, due to its excellent image resolution.
A key advantage of USG is its real-time dynamic evaluation, allowing functional assessment during movement or under stress, which is particularly valuable for detecting instability, tendon subluxation and impingement syndromes.[8] Additionally, concomitant use of Doppler settings also enhances ultrasound evaluation by identifying hypervascularity in conditions like active synovitis and tenosynovitis.[11]
It is also highly effective for monitoring the healing process, identifying fibrotic changes, and guiding interventions such as corticosteroid joint injections, platelet-rich plasma (PRP) injections[9] and dry needing.
Also, newer USG techniques like Sono-elastography provide information on tendons’ biomechanics and can be a great effective tool in evaluating tendon pathologies.[8,11] Despite these advantages, its limitations include difficulty in imaging deep structures and reduced accuracy in patients with high body mass. Furthermore, its efficacy is highly operator-dependent, requiring significant skill and experience to achieve reliable results.
Computed tomography (CT), although less frequently used as an initial investigation, plays an important role in specific conditions, such as evaluating complex fractures, small bone fragments, joint surface injuries, and subtle fractures that may be easily missed on X-rays. It provides detailed 3D images of bone, making it valuable in preoperative planning for fractures involving the ankle, knee, elbow, or shoulder. While less sensitive than MRI for soft-tissue evaluation, CT arthrography[12] can enhance detection of cartilage defects and labral tears in cases where MRI is unavailable or contraindicated.
Magnetic resonance imaging (MRI) remains the gold standard for the detailed evaluation of labrum, ligaments, cartilage and bone marrow.[9,11] In both upper and lower limb injuries, MRI provides excellent accuracy for evaluating suspected labral injuries, osteochondral defects, ligament tears, meniscal injuries, and early stress reactions, making it important in athletes, where early diagnosis can prevent further injury progression. Also, MR arthrography can be used to enhance the diagnostic sensitivity of labral tears[12] in the shoulder or hip, as well as minor capsular injuries that may be difficult to detect on standard MRI.
MRI has certain limitations, including higher cost and longer scanning times compared to other imaging modalities. In addition, it is not the modality for image-guided interventional procedures.
This is the first review article which attempts to comprehensively categorise sports-related injuries into two main regions: the upper limb and lower limb, within a single article. Each section outlines the most frequently observed injuries in different sports, the key anatomical structures affected, and the corresponding important imaging findings.
Previous publications have predominantly described sports injuries either in terms of the anatomical structures involved or according to the type of sport leading to the injury. Earlier reviews have generally addressed either upper limb or lower limb sports injuries in isolation, but not both together within a single article.
Upper Limb Sports Injuries
Upper limb injuries represent a significant proportion of sports-related injuries in athletes engaged in overhead and contact sports such as baseball, cricket, bowling, tennis, swimming, and volleyball.[13] This repetitive stress can lead to a spectrum of injuries, ranging from fractures, dislocation, tendinopathy, rotator cuff tears and instability to more complex conditions such as SLAP tears. Similarly, the elbow is a frequent site of overuse injury, with lateral and medial epicondylitis accounting for up to 50% of elbow conditions, particularly among racquet sport athletes and those exposed to repetitive wrist-driven actions.[6]
Upper Limb Fractures
Fractures of the upper limb are common in both contact and non-contact sports, arising from direct trauma, falls, or repetitive stress. The type and location of fracture often depend on the specific sport, the mechanism of injury, and the athlete’s age.[14]
X-rays remain the first-line and primary investigation of choice for suspected fractures. Standard orthogonal views are recommended, and in certain regions, specialised projections may be required for proper assessment.
CT plays a complementary role, offering detailed evaluation in cases of complex or comminuted fractures, fractures with intra-articular extension, or when precise anatomical detail is needed for preoperative planning. In most cases, MRI or ultrasound is rarely required for fracture assessment unless there is suspicion of associated soft-tissue injury, occult/early stress fractures, or physeal injuries.
A Few Common Sports-related Upper Limb Fractures
Clavicle fractures are among the most common fractures in adolescents and young athletes, usually caused by a direct blow to the shoulder or a fall onto an outstretched hand (FOOSH). They occur frequently in contact sports such as rugby, football, and combat sports, and in high-speed activities like skateboarding and skiing, where falls and collisions are frequent.[15] Most fractures occur at the midshaft of the clavicle with or without displacement and angulation [Figure 1].
Radiograph of the clavicle showing a comminuted, displaced fracture (blue arrow) of the clavicle at the junction of the mid and distal third in a young athlete caused by a direct blow to the shoulder
Proximal humerus fractures are seen in contact activities, skiing, and high-impact falls. These injuries show a bimodal distribution. In young athletes, they typically occur as physeal injuries in those involved in overhead or throwing sports. In contrast, in older athletes, they are more often the result of direct trauma, such as a fall onto the shoulder [Figure 2].[16] X-ray with standard AP, scapular Y, and axillary views are essential not only for confirming the fracture but also for accurate classification, such as with the Neer’s/AO classification system. CT is recommended for complex fractures and for the classification of fractures.
AP radiograph of the left shoulder showing a fracture (blue arrow) of the greater tuberosity of the humerus in an athlete as a result of direct trauma. AP: Anteroposterior
Scaphoid fractures are the most common type of carpal fracture.[17] They are particularly common in sports such as gymnastics, snowboarding, skateboarding, basketball, and football, where FOOSH are common. These injuries are most often seen in athletes between 15 and 30 years of age; most fractures occur through the waist of the scaphoid. Dedicated scaphoid-view X-rays are essential for initial assessment, although early fractures can be radiographically occult. MRI is the most sensitive modality for detecting early occult fractures.[18]
Metacarpal fractures are very common in boxing (‘boxer’s fracture’ affecting the fifth metacarpal neck), martial arts, rugby, and basketball.[19] The typical mechanism involves an axial load on a clenched fist or a direct blow. X-ray (PA, oblique, and lateral views) often demonstrates fracture of the fifth metacarpal neck with volar angulation, and rotational deformities may be apparent on oblique or lateral views.
Soft-tissue Injuries of Upper Limb
Shoulder Injuries
Rotator cuff injuries frequently occur in athletes engaged in sports activities that require repetitive overhead movements, such as tennis, baseball, volleyball, swimming, and cricket bowling. These injuries can vary in severity, ranging from tendinopathy to partial or full-thickness tendon tears. The supraspinatus tendon is most commonly affected, particularly at its articular surface.[20]
Rotator cuff injuries can be easily detected on ultrasound. On ultrasound, Tendinosis appears as hypoechoic thickening of the tendon, partial-thickness tears appear as focal hypoechoic or anechoic defects within the tendon [Figure 3], and full-thickness tears are identified as complete tendon discontinuity with a hypoechoic or anechoic gap, which may fill with fluid with tendon retraction. Additional findings can include fluid in the subacromial–subdeltoid bursa and cortical irregularity at the greater tuberosity.
(a) Longitudinal (b) transverse USG image of the shoulder joint, in an athlete with repeated overhead movements, shows a partial-thickness articular surface tear of the supraspinatus tendon (blue arrows)
On MRI, tendinosis is characterised by areas of high-signal intensity on T2-weighted or proton density fat-suppressed sequences (PDFS),[20] partial-thickness tears are characterised by focal fluid intensity defect within the bursal or articular surface of tendon fibres, and full-thickness tears show complete disruption of the tendon with retraction from its insertion and a fluid-filled gap. In chronic cases, secondary changes such as muscle atrophy and fatty infiltration may be seen.
SLAP (superior labrum anterior to posterior) tears are commonly seen in athletes who perform repetitive overhead movements[21] or high-torque movements, such as baseball pitchers, javelin throwers and volleyball players.
Ultrasound has a limited role in directly visualising the labrum; however, it can offer indirect indications, such as an adjacent paralabral cyst, which serves as additional evidence of an underlying labral tear. MRI is the imaging modality of choice in suspected SLAP injuries,[21] which usually appear as a fluid-signal cleft within the labrum, which may or may not extend into the biceps tendon, and are most clearly seen on fluid-sensitive sequences. Sometimes, there are associated paralabral cysts, which further support the diagnosis of SLAP tears.
Anterior glenohumeral instability is a common problem among athletes who participate in contact or high-impact sports such as rugby, wrestling, and basketball. It usually occurs after a traumatic anterior shoulder dislocation, but in throwing athletes, it can also occur slowly over time due to chronic overuse, which stretches and weakens the capsuloligamentous structures.[21]
MRI is the main imaging modality for evaluating shoulder instability. It shows the Bankart lesion [Figure 4] and its variant, which represents the tear of anteroinferior glenoid labrum with or without glenoid bone loss and the Hill-Sachs lesion [Figure 4], which is a cortical depression in the posterosuperior humeral head caused by impaction against the anterior glenoid rim.[22] MRI may also show capsular laxity and injury to the glenohumeral ligaments.
STIR oblique sagittal (a) and STIR axial (b) MR images of the shoulder show a bony Bankart lesion with detachment of the anteroinferior labrum from the underlying glenoid (blue arrows) and STIR axial (c) image shows a Hill-Sachs lesion (red arrow) in the posterolateral humeral head in a case of anterior shoulder dislocation in a wrestler. STIR: Short tau inversion recovery
Acromioclavicular (AC) joint injuries are common in athletes who play contact and collision sports such as rugby, football and wrestling, where direct falls onto the shoulder or high-impact collisions are frequent. These injuries can involve varying degrees of damage to both the AC ligament and the coracoclavicular (CC) ligament, and are typically classified using the Rockwood classification.[23]
On X-ray, AC joint injuries may appear as a widened joint space, upward displacement of the clavicle, increased CC distance, or loss of normal alignment between the clavicle and acromion [Figure 5]. Ultrasound can provide a quick evaluation of the AC joint, especially in acute cases. Injured ligaments on USG appear as hypoechoic or heterogeneously thickened, often with loss of their normal fibrillar pattern, which may be accompanied by joint effusion or widening. On MRI, AC joint injuries can be characterised by high T2 signal (Sprain) or discontinuity (tear) within the AC and/or CC ligaments, thickening of the joint capsule, adjacent bone marrow oedema, widening of the joint space, clavicular displacement, injury to deltoid and trapezius muscles, according to the severity by Rockwood classification [Table 1].
AP radiograph of the shoulder showing acromio-clavicular joint dislocation (blue arrow) due to a direct fall on the shoulder in a wrestler. AP: Anteroposterior
Rockwood classification for acromioclavicular injuries
Elbow Injuries
Medial epicondylitis, commonly known as ‘golfer’s elbow’, is an overuse injury that affects the origin of the common flexor tendon on the medial epicondyle of the humerus. It is common in sports that require repetitive wrist flexion and forearm pronation, such as golf, baseball pitching, cricket bowling, weightlifting, and javelin throwing.[24]
USG shows either focal or diffuse hypoechoic tendon thickening with loss of its normal fibrillar echotexture, with or without partial tears at the origin. Power Doppler can show increased vascularity in acute or subacute phases, indicating active inflammation. MRI is highly sensitive for identifying early changes, and it demonstrates thickening of the common flexor tendon with hyperintensity on T2-weighted or PDFS sequences and partial tears as fluid-filled defects within the tendon origin.[25]
Lateral epicondylitis, also known as ‘tennis elbow’, is an overuse injury that affects the common extensor tendon origin at the lateral epicondyle of the humerus, most commonly involving the extensor carpi radialis brevis. This condition is common in sports requiring repetitive wrist extension and forearm supination, such as tennis, badminton, and squash.[26]
USG shows either focal or diffuse hypoechoic tendon thickening, with or without partial tears at the origin. Dynamic USG scanning allows to look for other associated injuries, such as involvement of the radial collateral ligament or even slight radial head instability. MRI shows thickening of the common extensor tendon with increased signal on fluid-sensitive sequences, and in some cases, partial tears may be visible.[25]
Distal Biceps Tendon Tears are very important for athletes who do sports that require strong elbow flexion and supination, like weightlifting, wrestling, gymnastics, and throwing. These injuries mostly occur after a sudden, forceful eccentric contraction of the biceps.[27]
USG plays an important role in the evaluation of distal biceps tendon injuries. In complete tears, the tendon may be absent from its normal insertion site on the radial tuberosity, and there may be retraction of the tendon proximally with associated hematoma or fluid collection at the torn site. In partial tears, ultrasound usually shows hypoechoic thickening and focal defects in the tendon near its insertion, with or without associated bicipital-radial bursitis. On MR, acute complete ruptures show complete discontinuity of fibres with proximal tendon retraction, often associated with surrounding oedema or hematoma in the antecubital fossa. Partial tears may be visualised as thickening with focal fluid-filled defects without complete tendon detachment, with or without associated bicipital-radial bursitis.[28]
Wrist and Hand Injuries
Triangular Fibrocartilage Complex (TFCC) Injuries
TFCC injuries are frequently seen in sports like snowboarding, gymnastics, skateboarding, and goalkeeping that place sudden stress on the wrist. They can also occur in racquet sports, golf, and pole vaulting, in which repetitive torsional or distraction forces are applied to the wrist and forearm.[17]
The TFCC plays an important stabilising role at the distal radioulnar joint (DRUJ) and acts as a load-bearing cushion between the ulnar head and the carpals. It is a complex composed of several elements: the central articular disc, dorsal and volar radioulnar ligaments, ulnocarpal ligaments, the meniscus homologue, and the ECU tendon sheath.[17] On USG, the TFCC central disc is not fully accessible. Dynamic ultrasound during pronation-supination or ulnar deviation can highlight abnormal joint gapping or even ECU tendon subluxation associated with TFCC tears.[29]
MRI is the imaging modality of choice for suspected TFCC tears, which typically appear as areas of increased signal intensity within the fibrocartilage on fluid-sensitive sequences. These may be associated with DRUJ effusion, bony avulsions, or discontinuity of the dorsal/volar radioulnar ligaments. MR arthrography is especially helpful in identifying subtle or partial tears, as intra-articular contrast material outlines small defects and enhances visualisation of complex injuries.[30]
De Quervain’s Tenosynovitis is a painful condition caused by inflammation of the sheath that surrounds the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons in the first dorsal compartment of the wrist, developing from chronic friction and irritation of the tendon sheath.[31] It is often seen in sports requiring repetitive thumb abduction, wrist radial deviation, and gripping actions such as rowing, golf, volleyball, tennis and racquet-based sports.[17]
On USG, it is visualised as hypoechoic thickening of the APL and EPB tendons with fluid or synovial hypertrophy within the first extensor compartment, with thickening of the overlying retinaculum [Figure 6]. In acute cases, colour Doppler usually demonstrates increased vascularity in the synovial sheath.[31] Dynamic ultrasound can reproduce the patient’s pain by showing restricted tendon gliding during thumb movement.[29] On MRI, it appears as thickening of the APL and EPB tendons with increased signal on fluid-sensitive sequences, reflecting inflammation associated with fluid in the first extensor compartment.[32]
Transverse axis USG image of the 1st extensor compartment tendons (APL and EPB) of the wrist in a badminton player with De Quervain’s tenosynovitis showing hypoechoic retinacular thickening (yellow arrow) around the tendons, which correlates with the site of the pain with associated local hypervascularity (blue arrow)
Lower Limb Sports Injuries
Lower limb injuries are common in sports that involve running, jumping, sudden bursts of speed, or quick changes in direction. Among runners, injury rates range from nearly 20% to nearly 80% with the knee being the most commonly injured site, followed by the ankle, lower leg, and foot.[33] Muscle and tendon injuries, especially muscle injuries in the thigh (such as hamstrings and quadriceps strains), represent a large proportion of cases, while ligament injuries are mainly seen in the knee and ankle.
Fractures are a significant issue in high-impact and contact sports, constituting up to one-third of all sports-related fractures. Similar to the upper limb, the injury patterns in the lower limb also highlight the essential role of imaging in both diagnosis and management.
Common Lower Limb Fractures in Sports Injuries
Lower limb fractures remain a considerable challenge for both adolescent and adult athletes, frequently resulting from high-impact collisions, sudden pivoting movements, or repetitive stress.
Salter-Harris fractures are particularly common in young athletes with open growth plates.[34] These injuries primarily affect the physis (growth plate) and may extend into the metaphysis or epiphysis, depending on the fracture classification[35] [Table 2].
These injuries are common in basketball, track and field, baseball, soccer and gymnastics sports[36] due to their rapid changes in direction, high-impact landings, and twisting forces. It is very important to early and accurately diagnose these fractures, as delayed or missed recognition of physeal injuries can result in long-term complications such as growth disturbances, angular deformities, and limb-length discrepancies.
Avulsion fractures often occur during sports that put a lot of stress on tendon and muscle insertions, like kicking hard, sprinting, jumping, or making sudden changes in direction.[37] These are especially seen in adolescent and young adult athletes, as their growth plates (apophyses) are not yet fully fused. Common sites of avulsion fractures include the ischial tuberosity, anterior superior iliac spine (ASIS), anterior inferior iliac spine (AIIS), and tibial tubercle.
Early and accurate diagnosis of these injuries is essential to avoid complications such as chronic pain, malunion, or long-term functional impairment.[37]
Stress fractures are a type of overuse injury that occurs due to a mismatch between the bone strength and the mechanical stress placed upon it. These injuries are common in sports that require the lower limb to be loaded repeatedly, like long-distance running, gymnastics, and track and field events.[38] They are a part of the spectrum of bone stress injuries, starting with periosteal irritation and microdamage and progressing to complete cortical break if left untreated. Common stress fractures include: Tibial Stress fractures, Medial Tibial Stress Syndrome (MTSS), Metatarsal stress fractures and Femoral neck stress fractures.
X-ray is usually the first-line imaging investigation; however, it is often insensitive in the early stages. In later stages, stress fracture on X-ray may be visualised as a distinctive sclerotic line oriented perpendicular to the normal trabecular pattern, indicating the healing response of the bone. MRI is the most sensitive modality for early detection, as it can show bone marrow oedema, early periosteal oedema and fine fracture lines [Figure 7], before they become visible on X-rays.[39] The severity of the fracture line on MRI is assessed based on different MRI sequences, often using the Fredericson grading system[40] [Table 3]. Bone scintigraphy also plays an adjunct role, particularly in cases of multifocal lesions, by showing areas of increased tracer uptake corresponding to sites of stress reaction or fracture.
Coronal PDFS (a) and T1 (b) MRI image reveals tibial stress fracture in a runner in the form of a hypointense fracture line (blue arrow) with surrounding moderate marrow oedema (asterisk) in the medial tibial condyle. PDFS: Proton density fat saturated
Fredericson MRI grading system for stress fractures[40]
Common Hip and Groin Sports Injuries
Adductor (groin) strains are one of the most common soft-tissue injuries affecting athletes playing sports such as soccer and hockey. They typically occur when the adductor muscles, most commonly the adductor longus, are either overstretched or are subjected to a sudden, forceful contraction.[41]
Clinically, athletes present with acute pain along the medial aspect of the groin, localised tenderness over the muscle belly or tendon, and aggravated symptoms during resisted adduction. USG can show hypoechoic areas that correspond to partial or complete tears, as well as hematoma formation in more severe cases. MRI will show disruption of muscle fibres with accompanying fluid and oedema at the site of the tear, and is also useful for assessing the extent of injury.[42]
Athletic Pubalgia (Sports Hernia)
Athletic Pubalgia is a clinical syndrome characterised by chronic pain localised around the pubic symphysis, most often caused by musculotendinous or osseous injury, involving the insertion of rectus abdominis and adductor aponeuroses on the pubis [Figure 8]. It is most commonly seen in young adult male athletes participating in sports requiring rapid directional changes, twisting, and powerful kicking, such as soccer, ice hockey, rugby, tennis, basketball, and sprinting, where intense acceleration places high stress on the lower abdomen and groin.[43]
Axial (a) and Coronal (b) PDFS MRI images of the pelvis in a soccer player showing avulsion of the right adductor longus tendon from the pubis (blue arrows). PDFS: Proton density fat saturated
X-rays are often normal in soft-tissue injuries but may reveal features of osteitis pubis, such as subchondral sclerosis, irregular margins, and bone resorption. USG can show hypoechoic thickening of the aponeurosis, adjacent cortical irregularity, and, in severe cases, partial or complete tears of the rectus or adductor insertions, sometimes with muscle retraction, hematoma, or distension of the pubic symphysis capsule. MRI remains the investigation of choice. Typical findings include marrow oedema in the anteroinferior pubic bones and disruption of the rectus abdominis-adductor aponeurosis.[44] The ‘secondary cleft sign’, a fluid-sensitive high-signal line along the anteroinferior pubic ramus, suggests a partial tendon tear, while the ‘superior cleft sign’ along the superior pubic ramus also indicates injury.[34]
Rectus femoris injuries are common in athletic activities that involve frequent kicking, sprinting, or jumping. They range from contusions, strains, tears, and avulsions, with strains being the most frequent pattern. The rectus femoris is particularly vulnerable, as it spans both the hip and knee, and has a complex musculotendinous structure.[45] Injury most often occurs at the proximal myotendinous junction, but can also involve the origin, muscle belly, fascia, or distal junction.
In acute muscle injuries, USG typically demonstrates poorly defined hyper- or hypoechoic areas with varying degrees of fibre disruption or discontinuity. Chronic lesions may show thickened hypoechoic tendon, calcification or heterotopic ossification.[46] On MRI, muscle injuries usually appear as areas of fluid signal along and around the muscle fibres, involving the myofascial, myotendinous, or tendinous regions. MRI can clearly show the site, severity, and overall extent of the injury, as well as the degree of tendon or muscle retraction. A ‘bull’s eye sign’ suggests intramuscular degloving.[45]A clear radiology report should describe the site, type, and extent of the lesion, injury grade, degree of retraction, and associated findings to guide treatment planning and safe return to sport.
Muscle injury classification systems offer a standardised way to describe injuries, predict recovery times, and guide treatment decisions. The British Athletics Muscle Injury Classification (BAMIC)[47] [Table 4] grades injury severity, from 0 to 4, and specifies its location—whether myofascial (a), musculotendinous (b), or intratendinous (c). This approach makes BAMIC particularly useful for predicting recovery, as higher grades and intratendinous injuries are strongly linked to longer rehabilitation and a higher risk of re-injury.
Knee Joint Injuries
The knee is one of the most frequently injured joints in sports involving pivoting, jumping, sprinting, and contact, like football, basketball, and hockey.
Ligamentous injuries are caused by high-impact trauma, sudden deceleration, pivoting, or twisting activities and are common in sports, like football, basketball, skiing, and rugby, with the ACL being most commonly injured during non-contact pivoting or awkward landings.[48] PCL injuries usually result from a direct blow to the tibia, MCL injuries result from valgus stress, while LCL injuries arise from varus forces, often with posterolateral corner involvement.
USG is less effective for the cruciate ligaments, due to their deep anatomic location, but is a valuable tool for superficial ligaments (MCL and LCL) injury and may demonstrate hypoechoic thickening, and loss of the normal fibrillar echotexture with surrounding oedema in partial injury and discontinuity of the fibres in complete rupture.[49] It is also helpful in the dynamic evaluation of these ligaments using valgus or varus stress manoeuvres, revealing abnormal joint widening, thus confirming functional instability. MRI remains the modality of choice, showing high signal on T2-weighted or PDFS sequences, along with fibre irregularity or complete disruption. MRI also provides critical information on associated findings such as bone bruises, osteochondral injuries, and associated concomitant meniscal or cartilage damage, all of which are important for prognosis and surgical planning [Figure 9].[50]

Meniscal injuries are common in sports involving twisting, pivoting, sudden deceleration, or deep flexion, such as football, basketball, rugby, and skiing. The medial meniscus is more frequently affected due to its reduced mobility, while lateral meniscal tears are common with acute ACL injuries.[51]
USG is not the primary tool for assessing the meniscus due to its deep location; it can be a useful complementary technique in skilled hands, especially for detecting peripheral tears, meniscal cysts, and parameniscal fluid collections. Dynamic scanning and gentle compression can make extrusion more obvious or reveal fluid tracking from the tear site. MRI is the modality for diagnosing meniscal tears when intrameniscal signal extends to an articular surface on at least two consecutive slices, best seen on PDFS or T2-weighted fat-suppressed sequences. Certain tear types have distinctive appearances, like displaced tears, such as bucket-handle tears, which may show the ‘double PCL sign’ or ‘absent bow tie sign’, while radial tears are identified by a truncation of the normal triangular shape of the meniscus. Complex tears present with irregular shapes and mixed signal patterns.
Patellofemoral injuries are common in sports requiring repetitive knee flexion, jumping, and pivoting, such as basketball, soccer, and gymnastics. They range from acute patellar dislocation or subluxation, associated with medial patella-femoral ligament (MPFL) tears and osteochondral damage, to chronic conditions like pain syndrome and chondromalacia.
Typical MRI findings after acute dislocation include bone marrow oedema of the lateral femoral condyle and medial patella, MPFL discontinuity or thickening, joint effusion, and possible osteochondral fractures [Figure 10].[34] In chronic maltracking, MRI may reveal lateral patellar tilt, trochlear dysplasia, increased tibial tuberosity–trochlear groove (TT–TG) distance, and cartilage thinning or fissuring on T2-weighted and proton density–weighted sequences.[52]
Axial PDFS MRI image reveals typical findings of acute lateral patellar dislocation in a basketball player. The patella is laterally dislocated (blue arrow) with an osteochondral injury of the medial patella (red arrow), tears of the MPFL and medial retinaculum (yellow arrow). Bone bruise in the lateral femoral condyle and medial patellar facet (asterisks). PDFS: Proton density fat saturated, MPFL: medial patello-femoral ligament
Ankle Injuries
Ankle sprains most commonly involve the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), resulting from inversion and plantarflexion injuries in sports activities requiring rapid changes in direction, uneven landings, or collisions. Medial ankle injuries, which affect the deltoid ligament, are less frequent. Syndesmotic or high ankle sprains involving the anterior inferior tibiofibular ligament and the interosseous membrane are frequently encountered in sports that require twisting motions of the ankle under load, such as skiing, football, basketball and rugby.[53]
USG is particularly valuable for dynamic assessment of ligament integrity, enabling real-time visualisation of fibre discontinuity and thickening in acute sprains. It can also detect joint effusion, synovitis, and small avulsion fracture fragments.[54] MRI remains the investigation of choice, showing acute low-grade sprains as hyperintense on fluid-sensitive sequences, with complete ruptures showing clear fibre disruption. Bone marrow oedema, cartilage defects, and occult fractures are also well demonstrated on MRI [Figure 11].[53]
Axial PDFS (a) and T2 W (b) MRI images of the ankle in a football player showing a complete ATFL tear in the form of its non-visualisation (blue arrows). PDFS: Proton density fat saturated, ATFL: anterior talofibular ligament
Peroneal tendon injuries, including tears, subluxations, and dislocations, are common in athletes involved in sports with repetitive ankle eversion, abrupt directional changes, or explosive lateral movements, such as basketball, soccer, skiing, and trail running.
Dynamic USG, during dorsiflexion and eversion, can demonstrate subluxation or dislocation of peroneal tendons over the lateral malleolus, confirming superficial peroneal retinaculum (SPR) incompetence. Longitudinal split tears of the peroneus brevis show a characteristic ‘C-shaped’ configuration, with the tendon encasing the peroneus longus on both USG and MRI.[55]
Achilles Tendon Injury
The Achilles tendon is highly vulnerable in sports requiring explosive acceleration, rapid deceleration, or sudden directional changes, such as basketball, football, athletics, and tennis.[56] Achilles tendon injuries may be partial or complete tears, with complete ruptures usually caused by sudden forceful plantarflexion. Contributing factors for injury include poor warm-up, overtraining, pre-existing tendinopathy, and corticosteroid use.
On USG and MRI, a complete tear is characterised by disruption of tendon fibres with retracted ends; the intervening gap is often filled with fluid or hematoma. Partial tears show focal disruption of fibres with maintained overall continuity.[57] Early and accurate diagnosis is essential to restore optimal function, facilitate appropriate rehabilitation, and reduce the risk of re-rupture.
Plantar fasciitis is one of the most frequent causes of heel pain in athletes, particularly those involved in running and soccer.[58] It results from overuse-related microtears and degeneration of the plantar fascia, most often at its calcaneal attachment.
USG shows hypoechoic thickening (>4 mm) of plantar fascia with loss of fibrillar pattern, and increased vascularity in acute setting; chronic cases may reveal calcifications. Sono-elastography can also be used, and it provides a measure of tissue stiffness with gentle manual compression,[58] supplementing conventional USG findings. MRI demonstrates plantar fascia thickening with high T2/STIR signal, accompanied by adjacent bone marrow and soft-tissue oedema. Most athletes improve with rest, stretching, orthotics, and physiotherapy; however, resistant cases may require shockwave therapy, PRP injections, or rarely, surgery.
Foot injuries are common in sports that place high mechanical demands on the foot through running, jumping, and rapid directional changes.
Lisfranc ligament injuries are an important cause of midfoot pain and disability. These occur from high-energy trauma in sports like football or rugby, or low-energy twisting in running, gymnastics, or dance. These injuries often occur when an axial load is applied to a plantarflexed foot. This mechanism can cause anything from partial tearing to complete rupture, and in severe cases, fracture-dislocation.
Weight-bearing X-rays may show widening between the first and second metatarsal bases, misalignment at the metatarsal–cuneiform joints, or small avulsion fractures in severe cases. USG can sometimes identify ligament sprain/disruption, but its accuracy depends heavily on the operator’s skill. MRI is the most reliable tool, and shows areas of high signal on fluid-sensitive sequences, partial or complete ligament tears, and bone marrow oedema in adjacent bones. Timely diagnosis is important as missed injuries can lead to chronic midfoot instability, post-traumatic arthritis, and a long delay in returning to sport.[59]
Turf toe is a hyperextension injury of the first metatarsophalangeal (MTP) joint caused by forced dorsiflexion of the forefoot with the heel fixed, leading to sprain of the plantar plate and sesamoid apparatus. It is common in sports on artificial turf, such as football, soccer, and rugby, where surface grip and flexible footwear increase risk. MRI is the gold standard imaging modality, demonstrating oedema (sprain)/partial or complete tear of the plantar plate, capsular and surrounding soft tissues oedema, along with the marrow oedema in the metatarsal head or sesamoids.[60] Early diagnosis is essential to avoid chronic pain and persistent instability.
Limitations
This review primarily focuses on the imaging spectrum of sports-related injuries involving both the upper and lower limbs. The treatment and interventional aspects of these injuries were beyond the scope of this article. Management strategies, rehabilitation protocols, and interventional radiology techniques were not included in this review.
Conclusion
Radiological imaging is important in diagnosing, managing, and following up sports injuries and has greatly improved the ability to detect injuries early, guide treatment, and monitor recovery. To interpret injuries accurately, it is essential to understand the specific sport, the mechanism of injury, the types of tissues likely to be affected, and their characteristic imaging features on each modality in order to guide critical decisions that balance the athlete’s recovery, safe return to play, and continued participation in sport.
