Advance of Treatment of Anterior Cruciate Ligament (ACL) Injuries

of the Knee

Yuru Wei

Beijing No.4 High School International Campus, Beijing, China

Keywords: Anterior Cruciate Ligament (ACL) Injury, Diagnostic Imaging, Rehabilitation.

Abstract: This paper offers a comprehensive overview of anterior cruciate ligament (ACL) injury in sports involving

dynamic movement in terms of epidemiology, diagnostic workup, therapeutic management, and rehabilitation

innovation. ACL injury in such sports is classified into partial tears, complete ruptures, and combined injury,

with 70–80% caused by non-contact mechanisms due to biomechanical imbalances. Diagnosis is presented in

terms of various modalities, namely physical examination (e.g., Lachman test), MRI (gold standard for

imaging soft tissue), ultrasound, and X-rays, with a description of their hierarchical use: primary screening

through physical examination and X-rays, and MRI confirmation in the majority of instances, with ultrasound

for dynamic follow-up in select groups. Treatment is differentiated between surgical (autografts, allografts,

artificial ligaments) and conservative (rehabilitation, bracing, new biologics), with surgical reconstruction for

active patients and conservative management for elderly or comorbid patients. Rehabilitation protocol

outlines phased steps with the use of neuromuscular training, proprioceptive exercises, and new technology

in the form of photobiomodulation (PBM) for reducing inflammation and aligning collagen, and surface

electromyography (sEMG) feedback for optimal pattern of activation of the muscles. Innovation in the article

lies in its tiered diagnostic streamlining, enabling context-specific combinations of imaging modalities (e.g.,

MRI-ultrasound synergy in pediatric injury), as well as in its focus on new rehabilitation technology for

functional optimization. By spanning various disciplines of knowledge, the study delineates the path towards

individualized medicine as well as better outcomes for ACL injury, bridging lacunae in early detection,

minimally invasive procedures, and individual rehabilitation templates.

1 INTRODUCTION

Originating from the posteromedial aspect of the

lateral femoral condyle, the anterior cruciate ligament

attaches onto the anterior intercondylar portion of the

tibia, just anterior and slightly lateral to the medial

intercondylar tubercle, and partially blends with the

anterior portion of the lateral meniscus. Its collagen

bundles are separated into anteromedial and

posterolateral bundles, and it inserts anterior to the

tibial intercondylar eminence (Standring, 2021). The

ACL physiologically preserves the mechanical

stability of the knee during dynamic movement by

restricting anterior tibial translation and regulating

rotational and internal and external rotational forces.

The tension in the anteromedial (AM) bundle

escalates with knee flexion, while the posterolateral

(PL) bundle has heightened tension during extension

and in reaction to linked internal rotation (Georgoulis,

A D et al., 2010).

Based on the degree of ligament injury and

associated structural involvement, ACL injuries can

be divided into three primary categories: partial tears,

total ruptures, and combined injuries. A partial loss of

knee stability results from partial tears, which are

caused by partial ligament fiber rupture that preserves

continuity. Complete ruptures indicate complete loss

of continuity of the ligament, resulting in significant

instability of the knee joint. Combined injuries are

commonly linked with meniscus injury, medial

collateral ligament or posterior cruciate ligament

damage, and articular cartilage damage. These types

have a direct impact on the choice of clinical

treatment strategy and prognostic assessment.

As one of the most common musculoskeletal

conditions, ACL injuries’ frequency has increased

rapidly in the past few decades. Between 200,000 and

250,000 ACL injuries occur annually in the United

States. About 25% of these injuries occur in children

under the age of 18, and men are more inclined than

412

Wei, Y.

Advance of Treatment of Anterior Cruciate Ligament (ACL) Injuries of the Knee.

DOI: 10.5220/0014494300004933

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 1st International Conference on Biomedical Engineering and Food Science (BEFS 2025), pages 412-419

ISBN: 978-989-758-789-4

women to suffer a ruptured ACL overall, mostly as a

result of playing in more team and contact sports

(Arundale, Amelia J H et al., 2022). But when it

comes to physical activity, women are regularly

proven to be more vulnerable, even though men

sustain most injuries since they are more likely to

engage in athletic activities (Gianotti, Simon M., et

al., 2009). Sex differences in anatomy, hormones,

neuromuscular control, and kinematics are most

likely the reason of the discrepancy in ACL injury

rates. Males and females differ in the neurological

regulation and biomechanics of the hips and trunk in

each of the three planes of motion (sagittal, coronal,

and transverse). Females exhibit more lateral trunk

displacement, higher trunk and hip flexion angles,

and wider trunk motion ranges than males. Due to

differences in landing techniques between the sexes,

as well as their increased joint laxity and decreased

torsional stiffness, females may be more prone to

ACL injuries (Hewett, Timothy E et al., 2016).

Across all youth sports, female athletes have an

almost one in ten thousand chances of suffering an

ACL injury, which is nearly 1.5 times the risk for men

athletes; a female athlete who participates in several

sports is thought to have a roughly 10% chance of

suffering an ACL damage during her time in high

school or middle school. Adolescents who play

soccer, basketball, lacrosse, and other sports, both

male and female, are especially vulnerable to injury

(Bram, J. T., Magee, L. C., Mehta, N. N., Patel, N.

M., & Ganley, T. J., 2021).

Anterior cruciate ligament (ACL) injuries are

usually triggered by abnormal loads placed on the

knee, and the specific mechanisms can be categorized

into two types: contact and non-contact injuries. Non-

contact injuries account for 70%-80% of ACL

injuries and are not caused by direct external impacts,

but by uncontrolled movement of the knee joint itself

during sports. Non-contact injuries are most common

in sports that require rapid changes of direction,

jumps or sharp stops. For example, when a soccer

player stops sharply to turn, the knee is in a position

of flexion, valgus (inward buckling of the knee), and

external rotation, at which point the shear forces of

anterior tibial translation and rotation can exceed the

tolerance limits of the ACL, resulting in ligament

tearing. A similar situation occurs when a basketball

player lands unsteadily on one foot after a jump, or

when a skier changes direction during a sudden

deceleration in a high-speed glide. In a specific case,

during a basketball game, a 23-year-old man had a

non-contact pivoting injury to his left knee while

changing direction and slowing down. He was unable

to support his weight after feeling a "pop" in his knee.

As soon as the court helped him, he realized that his

knee was swollen. Although pain and swelling

limited examination during the acute phase, the

collateral ligaments were found to be clinically intact.

A full, mid-substance ACL rupture was seen on a

magnetic resonance imaging scan (Wall, Chris et al.,

2023). 95% of ACL injuries sustained by Norwegian

top division handball teams during two seasons

happened without any player contact, according to a

registry that documents these injuries (Dai, B.,

Herman, D., Liu, H., Garrett, W. E., & Yu, B., 2012).

The common feature of these maneuvers is that the

knee joint is subjected to abnormal stresses due to

biomechanical imbalances during dynamic motion.

The core causes of non-contact injuries are related to

several biomechanical factors. The first is knee

valgus (internal buckling); when landing with the

knee at an internal buckling angle of more than 8

degrees, the load on the ACL spikes to more than

three times its normal value. The second is muscle

coordination imbalances, particularly quadriceps

overpowering and hamstrings delaying activation to

effectively limit anterior tibial translation. In

addition, inadequate strength in the core muscles can

lead to a shift in the center of gravity of the body,

further exacerbating torsional stress on the knee joint.

Foot problems such as flat feet or excessive internal

rotation can also alter force transmission pathways

and increase the risk of ACL injuries. Conversely,

contact injuries occur when the knee is directly

subjected to external forces. The ACL is subjected to

tensile or shear stresses that exceed its physiological

limits as a result of contact with the outside

knee,

which causes excessive anterior tibial translation,

external rotation, or internal rotation. Higher energy

mechanisms of injury are usually the cause of

contact-type mechanisms. Traumatic knee

dislocations or high-energy on-field injuries may fall

under this category. Similar to the non-contact injury,

hyperextension, or collision, can occur when the knee

experiences valgus or varus stress in the form of

translation and shearing motion (Wetters, Nathan, et

al., 2016). This finally leads to a ligament rupture.

Typical scenarios for this type of injury include a

sideways scoop in soccer, a tackle against a tackle in

rugby, or a direct hit to the knee in a traffic accident.

For example, in rugby, when an athlete's knee is hit

laterally by an opponent at a high speed, the knee

momentarily externally rotates and combines with

rotation, which often leads to a combined injury of the

ACL and the medial collateral ligament (MCL), or

Advance of Treatment of Anterior Cruciate Ligament (ACL) Injuries of the Knee

413

even accompanied by a meniscus tear. Another risk

factor is due to sex and hormones.

2 DIAGNOSIS

Symptoms and signs of anterior cruciate ligament

injury change dynamically at different stages. In the

acute stage of the injury, patients often feel sudden

and severe pain during knee flexion movements (such

as stopping sharply, jumping, and landing). They

typically report a popping sound followed by sudden

knee pain and swelling, using the "double fist sign"—

that is, rotating their fists in a grinding motion with

their faces facing each other—to express their sense

of instability (Cimino, Francesca, Bradford Scott

Volk, and Don Setter, 2010). Within 1-2 hours after

the injury, intra-articular hemorrhage due to ligament

tearing leads to the rapid formation of obvious

hematoma, at this time, the joint is swollen and

bulging, the skin temperature rises, the activities are

severely limited, and the flexion and extension

movements can cause sharp pain. In the following 24

hours, the fluid accumulation gradually increased,

causing persistent swelling and pain. Patients

complain of knee “tenderness” or “misalignment”

when walking, especially when turning around or

walking up and down stairs, and some are forced to

adopt a “bent-knee gait” due to acute pain and

quadriceps muscle inhibition (inability to contract the

muscles on their own) that prevents them from

completing straight-leg raises. Some people are

unable to perform straight leg raises due to acute pain

and quadriceps muscle inhibition (inability to

contract the muscles on their own), and are forced to

adopt a “bent-knee gait”—walking with the knee

slightly flexed and the stride shortened to reduce the

load. If not treated in time and enter the chronic stage,

knee joint instability persists, repeated “giving way”

phenomenon may occur in daily activities (such as

walking, turning), and even sudden loss of control

kneeling. Long-term instability leads to repeated

small injuries to the joint, which can lead to

secondary lesions: meniscus tear manifests itself as

interlocking (sudden jamming during activities) and

localized pressure and pain, while cartilage abrasion

manifests itself as persistent hidden pain, morning

stiffness or swelling after activities. Physical

examination reveals atrophy of the quadriceps muscle

(due to long-term pain-avoidance muscle inhibition),

a further decrease in joint mobility (less than 90° of

flexion and limited extension), and early signs of

osteoarthritis (e.g., friction sensation in the joints) in

some patients. According to prior research, even

though ACL restoration is common, as many as 80%

of patients may experience knee osteoarthritis (OA)

in the ten to fifteen years afterwards (Azus, Aisia, et

al., 2018).

Physical Examination examines the functional

integrity of the ACL by reproducing the force status

of the knee joint through biomechanical maneuvers,

for which three methods are regularly used. Firstly,

the Lachman test: the patient lies supine, the examiner

keeps the distal femur clamped with one hand and

moves the proximal tibia anteriorly with the other

hand (20°-30° knee flexion). Its positive form is an

increase in anterior tibial displacement with no end

point, 85%-90% sensitive, most reliable test in the

acute phase. Second, the anterior drawer test: the tibia

is drawn anteriorly with the knee flexed to 90° in

order to assess anterior laxity. As the hamstrings are

able to contract compensatorily in the flexed position,

the sensitivity is reduced to 60%-70% and is more

applicable to chronic injuries. Thirdly, axial shift test:

passive extension of the knee and valgus stress,

progressive flexion of the knee when the tibial

epicondyle "misalignment sensation", high

specificity (>90%), but requires the patient to relax,

difficult to cooperate with the acute phase due to pain.

The Physical Examination benefits are non-invasive,

immediate patient feedback, and low cost. However,

its disadvantages are that the findings are operator-

dependent, false negatives may occur in the acute

phase due to swelling or muscle spasm, and the

degree of injury cannot be quantified. Therefore,

Physical Examination is suitable for acute initial

screening and sports-side assessment.

Magnetic Resonance Imaging (MRI), a high-

resolution soft tissue imaging technique, can directly

view the ACL's continuity, the tear's location, and any

associated lesions (such as meniscus and cartilage

damage). Additionally, it possesses high safety,

multiparameter, and multiplanar imaging features.

For ACL damage, MRI direct signs—that is, direct

pathological alterations at the lesion site—had a high

diagnostic value. Of these, ACL edema and thickness,

discontinuity, and abnormal alignment have a

significant diagnostic value (Zhang, Y. J., Jiang, Y.

Y., & Liu, C. H., 2024). MRI has very high soft tissue

resolution, with a diagnostic accuracy of greater than

95%, and can differentiate between a partial tear

(partial fiber continuity) and a complete break. It is

appropriate for pregnant women and children and

does not emit radiation. It is important to note,

though, that MRIs are often 10–20 times more costly

than X-rays. Additionally, it is time-consuming and

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could result in false-negative findings for minor

injuries or chronic scarring.

Ultrasound utilizes high-frequency sound waves

to dynamically scan the ACL and is suitable for

visualizing the ligament morphology and status in

motion. The normal ACL is diagnosed

ultrasonographically as a homogeneous, highly

echogenic fascicle extending from the lateral femoral

condyle to the intercondylar ridge of the tibia. Injury

to the ACL manifests itself as localized hypoechoicity

(edema), interruption of fibers, or thickening

(scarring). The benefits of ultrasound include being

radiation-free, portable, and suitable for screening

children, pregnant women, and low-resource areas.

Its real-time dynamic evaluation capacity allows for

the observation of changes in ligament tension during

knee flexion and extension. However, ultrasound

necessitates a high degree of technical expertise from

the operator, who must be familiar with the knee's

anatomy. And, deep structures, such as the posterior

bundle of the ACL, have inadequate resolution.

Imaging quality is reduced in obese or severely

swollen patients. Therefore, ultrasound is often used

as a complement to MRI rather than as a stand-alone

diagnostic tool.

Computerized Tomography (CT) is used to

accurately visualize bony structural abnormalities

(e.g., complex fractures, intercondylar ridge

avulsions) through three-dimensional bone imaging,

and is used for polytrauma or preoperative planning.

CT has good diagnostic value for knee fractures

because it can visualize the bony structure of the

knee, with the advantage of rapid scanning and clear

bone detail. However, due to the high water content

of ligamentous tissue, the relatively uniform density

of soft tissue, and the lack of significant density

changes after injury, CT findings do not allow for a

definitive assessment of the severity of ligamentous

or soft tissue injuries. At the same time, CT carries a

risk of radiation exposure, so it is usually used only

when there is a suspicion of combined severe

fractures. Since it is less likely to produce a

comprehensive image and direct visualization of the

ACL, CT can only be utilized in conjunction with

indications of fracture, osteoporosis, tibial

dislocation, and bone contusion (Sun Yadong & Zhu

Limin., 2023).

Diagnostic X-rays show bony structures through

penetrating X-ray imaging, commonly used positions

include orthostatic, lateral, and intercondylar fossa

(tunnel view). The direct signs are usually not

abnormal, but it is possible to rule out a tibial plateau

fracture or an ACL stop avulsion, which is an

avulsion of the intercondylar ridge. The indirect sign

of a Second fracture (avulsion fracture of the lateral

tibial plateau) is highly suggestive of an ACL injury

(specificity >90%). X-rays have the advantages of

being efficient (completed in less than 5 minutes),

economical, and widely available. It suggests the

possibility of ACL injury through indirect signs.

However, X-rays do not directly show ligament or

soft tissue damage and are of limited diagnostic value

for simple ACL injuries. They are only used as an

adjunctive tool to initially rule out skeletal problems.

Therefore, X-rays are suitable for acute trauma to rule

out fractures and for preoperative skeletal

morphology assessment.

3 TREATMENTS OF ACL

INJURIES

The aim of ACL treatments is straightforward. Its

goals are to address deficits, restore functional

stability, and safely return to sports; to be specific,

there are several phases: the acute phase after the

injury focuses on the elimination of residual

symptoms (effusion and pain) and impairments

(range of motion and quadriceps activation), the

subsequent phase includes neuromuscular and

perturbation training to improve knee stabilization,

and the final phase aims to further optimize muscular

strength, return to preinjury sport level through

specific exercises, and assess psychological readiness

for the return to sport (Diermeier, Theresa Anita, et

al., 2021). The decision on different types of

treatment is essential as well. Factors that affect the

decision may include patients’ age, physical activity

level, types of injuries, etc. There are two main types

of treatments: Surgical Treatment and Non-Surgical

Treatment (Conservative Treatment).

3.1 Surgical Treatment

The main surgical approaches include replacing the

ACL with a patellar tendon autograft, popliteal

tendon autograft, quadriceps tendon autograft, or a

tendon graft consisting of a patellar tendon, Achilles

tendon, or popliteal tendon allograft. This treatment

is primarily indicated for younger patients with a

complete ACL rupture who require a return to sport

or have a combined meniscal reparable injury or other

ligamentous injury. Currently, the main common

surgical approaches include autograft, allograft, and

Advance of Treatment of Anterior Cruciate Ligament (ACL) Injuries of the Knee

415

artificial ligament reconstruction. Surgical Treatment

has a long-term success rate of 82% to 95%.

The most common surgical treatment is an

autograft. Specifically, patellar tendon-bone grafts

can help provide excellent initial stiffness and

fixation strength in athletes who require a high degree

of knee stability. However, this treatment may lead to

donor area complications such as anterior knee pain

or patellar tendinitis, resulting in compromised

postoperative rehabilitation.

Another common autograft technique is

hamstring tendon grafting using the thin femoral and

semitendinosus muscles. Although it is slightly

weaker compared to patellar tendon-bone grafts, it

can reduce patient pain and donor site complication

symptoms. It is crucial to remember that in the

postoperative phase, the popliteal tendon may

become lax, which can negatively affect the long-

term stability of the knee.

Allografts are an alternative option in surgical

cases faced with multiple ligament injuries or

requiring revision surgery. However, the use of

allogeneic grafts carries a potential risk of immune

rejection and infection, so they must be thoroughly

examined and managed.

Artificial ligaments such as LARS (Ligament

Advanced Reinforcement System) are very useful for

patients who wish to recover quickly during specific

surgical procedures. Unfortunately, its use is limited

by its high wear rate and risk of re-rupture.

In terms of surgical technique, minimally invasive

ACL reconstruction using arthroscopic assistance

significantly reduces postoperative pain and tissue

damage and speeds up recovery compared to

traditional open surgery. There are two types of

reconstruction: anatomic single-bundle

reconstruction and double-bundle reconstruction.

Double-bundle reconstruction is anatomically closer

to the distribution of the original ACL and

theoretically provides better rotational stability.

However, it is technically complex and time-

consuming, so it is not applicable to all patients.

The post-operative rehabilitation phase is also a

key part of treatment. It requires following a

scientific, staged rehabilitation process. The main

considerations include joint mobility, muscle

function, neuromuscular control, modifications

related to the type of graft, meniscal repair, and

ligamentous co-surgery. Postoperative rehabilitation

is usually divided into three phases: 0 to 6 weeks to

protect the graft, limit activity, and prevent re-injury;

6 to 12 weeks to restore knee mobility and

plyometrics, with a gradual return to weight-bearing;

and 3 to 6 months to the reconstruction of athletic

function in preparation for return to athletic activity

or competition. The whole rehabilitation process

should be carried out under professional guidance to

ensure the stability of ligament reconstruction and

complete recovery of knee function.

3.2 Non-Surgical Treatment

(Conservative Treatment)

Although surgery is the preferred treatment for most

people who experience an ACL injury, conservative

treatment is also an effective option. It is mainly for

patients with fair stability of the partially torn cut

knee, especially the elderly and non-athlete

population. It is also recommended to prioritize non-

surgical treatment for patients with contraindications

to surgery such as severe cardiopulmonary disease.

The core of conservative treatment is systematic

rehabilitation, which is usually carried out in stages.

In the early treatment phase, the focus is on

controlling joint swelling and pain, using the

“POLICE” principle (Protection, Optimal Loading,

Ice, Compression, Elevation), and starting passive

and active Range of Motion (ROM) training to

prevent joint stiffness. At the same time, passive and

active ROM training is started to prevent joint

stiffness. In the middle stage, the focus of

rehabilitation shifts to neuromuscular control and

strength training, especially hamstring and core

muscle strengthening training, which helps to

enhance the stability of the back of the knee; at the

same time, proprioceptive training needs to be carried

out to improve the patient's perception of the position

of the knee joint and the state of the movement, to

prevent accidental sprains. In the late stage,

functional training is the main focus, simulating daily

activities or mild sports movements, laying the

foundation for the recovery of life functions or even

some sports functions.

In addition, the knee brace occupies a significant

role in conservative treatment. It prevents anterior

shifting of the tibia and safeguards stability, reducing

the risk of knee instability during sports. Recently,

biological therapies such as platelet-rich plasma and

stem cell injections are also gaining attention. Their

goal is to promote ligament tissue regeneration by

activating the body's local repair response. However,

these therapies remain controversial in the

management of ACL injuries and their effectiveness

has yet to be proven.

Advantages of conservative treatment include

avoidance of surgical risks, minimal trauma, flexible

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recovery cycles, and a paid-off financial burden.

However, its limitations are also obvious. In

demanding sports, it is challenging to reestablish a

knee joint's dynamic stability, and may even increase

the risk of secondary knee injuries in the long term.

Therefore, when deciding whether or not to adopt

non-surgical treatment, a detailed and careful

assessment is required before making a decision.

4 REHABILITATIONS

4.1 The Standard in Traditional

Physical Rehabilitation

The rehabilitation process after an ACL injury is also

important as it enables knee function to return and the

chances of re-injury to be reduced. The most widely

employed standardized approach by physical

therapists is generally separated into three phases,

early, mid, and late, according to time post-treatment,

to enable a progressive return of function.

The primary objectives for the first stage of

rehabilitation (0 to 6 weeks after surgery) include the

management of post-op reactionary swelling and

pain, restoration of knee mobility, and early initiation

of neuromuscular activation training. Compression

and cold packs are the standard in swelling control,

whereas using Continuous Passive Motion (CPM)

machines is instrumental in restoring joint mobility

and preventing adhesions. Simple exercises like ankle

pump exercise and quadriceps isometric contractions

are suitable for neuromuscular activation, prevention

of muscle atrophy, and the basis for subsequent

training.

The middle phase of rehabilitation (6 to 12 weeks

after surgery) is aimed at the weight-bearing

reconstruction and dynamic stability rehabilitation

exercise. Closed-chain exercises, such as wall static

squats, are considered less stressful to the joint with

weight-bearing exercise and appropriate to aid with

restoration of stability. Yet, open-chain movement

(i.e., leg extension and flexion) can more effectively

strengthen the quadriceps directly. The patients need

to choose between the two exercises depending on

their individual status and

postoperative course.

Dynamic balance training, however, enhances

proprioception and coordination through the use of

equipment like balance cushions. Improvement in

dynamic balance was significantly and negatively

related to the risk of re-injury in a study, and thus this

phase of training is required (Grindem H, Snyder-

Mackler L, Moksnes H, et al., 2016).

The key goal of the postoperative rehabilitation

phase (12 weeks or more postoperatively) is to restore

sport-specific abilities, particularly biomechanical

control during jumping and landing. By evaluating

and correcting the patient's knee forces and landing

position during high speed sports, the Physical

Therapist can effectively minimize the risk of

secondary injury to the non-contact ACL. Only when

biomechanical control is corrected can the knee have

adequate functional symmetry and safety during high

intensity sports.

4.2 Evidence-Based Breakthroughs in

Emerging Rehabilitation

Technologies

Rehabilitation approaches regarding ACL injuries

continue to evolve and improve as rehabilitation

therapy and technology converge. More and more

emerging technologies are being introduced into

clinical medicine and continue to be supported by

research.

Photobiomodulation (PBM) is a non-invasive

treatment. It induces biological levels at the cellular

level by means of red light of a specific wavelength.

In the early postoperative period after ACL surgery,

the application of red light with a wavelength of 650

nm can significantly inhibit the release of

inflammatory factors, thus reducing the local

inflammatory response after surgery. Meanwhile, 810

nm near-infrared laser can promote the longitudinal

alignment of collagen fibers. During ligament

regeneration, this facilitates the reconstruction of

tissue structure and the recovery of mechanical

properties. This therapy, while still advancing,

already has preliminary evidence to support its

potential.

In the rehabilitation of ACL injuries, feedback

from surface electromyography (sEMG) can help

assess and train synergistic contractions of the

quadriceps and hamstrings. sEMG monitors muscle

activation in real time and helps patients correct their

force generation style through timely feedback, thus

improving knee stability. Failure of quadriceps

activation as measured by EMG techniques remains a

significant factor preventing full strength recovery

after ACL reconstruction (Grooms, Dustin, Gregory

Appelbaum, and James Onate, 2015). This finding

supports the introduction of EMG feedback in

postoperative rehabilitation to optimize training

outcomes.

Advance of Treatment of Anterior Cruciate Ligament (ACL) Injuries of the Knee

417

5 CONCLUSION

As a common and highly prevalent soft tissue injury

in sports medicine, anterior cruciate ligament (ACL)

injury of the knee has a profound impact on the

patient's sports function and quality of life. Starting

from the epidemiologic background of ACL, this

article sequentially discusses its diagnostic methods,

treatment means and rehabilitation strategies, and

strives to provide systematic reference for clinical

practice.

Currently, although imaging techniques such as

MRI have found wide usage in the diagnosis of ACL,

still there are limitations regarding early detection and

precision. For treatment as well, both conservative

and surgery have their positives, although the latter

requires a program on case-by-case basis based on the

patient's individual condition. Concurrently, ACL

rehabilitation becomes necessary in a bid to reclaim

knee function, and novel approaches such as optical

therapy and neuromuscular training are gaining

prominence as technology advances.

Combining the functions, advantages, and

disadvantages of the ACL assessment methods

mentioned above, the author summarizes the

optimization and tiered application of the diagnostic

process. Firstly, the initial assessment is based on

Physical Examination combined with X-ray

examination, aiming at the rapid exclusion of

fractures and skeletal abnormalities. Secondly, MRI

was preferred for confirming the diagnosis due to its

high soft tissue fraction and multiplanar imaging

capability, which can be used to clarify the extent of

ligament and soft tissue injuries. Ultrasound, on the

other hand, is used for dynamic monitoring and

screening in specialized scenarios, such as resource-

limited areas. In children, it is recommended that

ultrasound screening be prioritized, thereby reducing

radiation exposure, and then combined with MRI to

confirm subtle injuries. In pregnant women and

women of childbearing age, X-rays and CT Scans

need to be strictly avoided, with MRI as the

diagnostic tool of choice.

Overall, the diagnosis and treatment of ACL

injury has gradually formed a more mature system,

but there is still a broad space for development in

terms of accurate diagnosis, minimally invasive

surgery, and individualized rehabilitation. Future

research should further integrate multidisciplinary

means to provide patients with more scientific and

efficient comprehensive treatment programs.

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