Treatment Methods for Anterior Cruciate Ligament (ACL) Injuries

Xiangqian Ling

Shanghai YKPAO School, Shanghai, China

Keywords: Anterior Cruciate Ligament (ACL) Injury, Rehabilitation, Digital Therapy.

Abstract: Anterior cruciate ligament (ACL) injury is prevalent in sports players and physically active people and causes

significant morbidity and functional impairment. In this review, the epidemiology, methods of diagnosis,

methods of treatment, and rehabilitation regimens of ACL injury are addressed in a systematic manner.

Particular emphasis is placed on the advantages and disadvantages of current surgical procedures, including

arthroscopic reconstruction, and emerging non-surgical interventions, including digital therapy. In addition,

the diagnostic contribution of MRI and physical examination is sharply evaluated. The findings emphasize

the importance of personalized rehabilitation programs and use of emerging technologies to improve patient

outcomes.

1 INTRODUCTION

One of the significant ligaments found in the human

body is the anterior cruciate ligament, particularly for

the stability of the knee joint. It has a crucial function

of preventing the sliding forward of the tibia against

the femur and helps prevent rotational instability.

Damaging the ligament will result in serious

impairment, particularly for athletes or physically

active patients. Sports ACL injuries are commonly

associated with jumping, pivoting, or most abrupt

stops that participate in sporting events, which are

soccer, basketball, skiing, and football. Over the last

few years, the rate of ACL injuries has been rising,

mostly due to increased involvement in sports and

physical activity across various age groups. The

effects of injuries are not only physical but also result

in prolonged periods of inactivity, loss of function,

emotional distress, and expense of medical treatment

and rehabilitation. The effects of injuries are not only

physical but also result in prolonged periods of

inactivity, loss of function, emotional distress, and

expense of medical treatment and rehabilitation. The

individual and social impacts of ACL injury have

promoted a rapid rate of research and innovation on

their prevention, diagnosis, treatment, and

rehabilitation (Anderson & Wu, 2020). This article is

a review of the management and practice of ACL

injury. There is a detailed review of the epidemiology

of ACL injury with the usual risk factors and

demographics involved. Diagnostic modalities in

terms of physical examination tests and imaging are

discussed. Following diagnosis, different treatment

options are weighed whether surgical or not. The

paper also deals with the process of rehabilitation,

with the modern digital methods employed in

rehabilitating patients to recover from an ACL injury

being given much importance. Injuries to the ACL

happen in a diverse population but predominantly in

athletes. The global prevalence has been increasing

steadily, at least partially due to higher levels of

sporting participation, particularly in youth and

females. Evidence shows that female sportsmen are at

greater risk of developing ACL injuries compared to

their male counterparts. This has been attributed to

anatomical variations such as a broader pelvis,

hormonal effects, and neuromuscular control

differences.

Table 1. ACL Injury Incidence by Population Group.

Population Group Incidence Rate (Pe

100,100)

General Population 68.6

Male Athletes 85.0

Female Athletes 120.0

Adolescents 130.0

As table 1 shows, adolescents have a higher

incidence rate compared to adults, which indicates

that age is also a factor. Adolescents and young adults

engaging in sports with high intensities are most

commonly involved (Anderson & Wu 2020).

However, ACL injuries are not limited to athletes.

448

Ling, X.

Treatment Methods for Anterior Cruciate Ligament (ACL) Injuries.

DOI: 10.5220/0014495100004933

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 448-452

ISBN: 978-989-758-789-4

They can occur in non-athletes due to falls, car

accidents, or sudden missteps that overexert the knee

joint. Besides, as table 1 shows, gender also plays a

role in incidence rate.

Figure 1 rising trends of ACL injuries in youth athletes

(2010–2024).

Biomechanically, ACL injuries are typically

caused by non-contact mechanisms. These include

sudden deceleration, poor landing mechanics, and

unexpected alterations of direction (Polhill, 1982).

These movements place the knee joint under

excessive stress, especially when there is poor

muscular control or quadriceps-hamstring imbalance.

Individuals with weak core stability or impaired

proprioception are also more susceptible. Untreated

ACL injuries have severe long-term effects. Besides

the initial instability and pain, there is also a high

likelihood of secondary cartilage or meniscus injury.

Such damage can ultimately lead to chronic

instability and osteoarthritis that occur prematurely.

(Filbay & Grindem 2019). This underscores the

importance of early and proper diagnosis followed by

effective intervention (O’Connor, 2020).

2 DIAGNOSIS

The diagnostic work-up of ACL injuries begins with

a comprehensive clinical examination. Clinicians

make a working diagnosis by a blend of patient

history, physical examination tests, and imaging

studies. In table 2, it presents the ideas of different

methods and their clinical effectiveness, which can be

linked to physical examination for diagnosis.

Physical examination plays a very important role in

the diagnosis (Anderson & Wu 2020). The lachman

test is usually considered the most sensitive test of

ACL damage (lee 2018). To perform the lachman

test, place the knee in a reduced amount of flexion and

apply an anterior force to the tibia. More anterior

translation of the tibia than the opposite knee is a

positive test. Another useful test is the anterior drawer

test, which also checks for anterior displacement of

the tibia. (Filbay, Grindem 2019). Pivot-shift test,

though technically more challenging, is an ACL

injury-specific and evaluates rotational instability.

However, physical tests are not perfect. Swelling,

pain, or muscle guarding can influence the validity of

a test (Zhou, H,2019).

Therefore, imaging techniques have an important

supporting role to play. Magnetic resonance imaging

(MRI) is the gold standard for visualization of the

ACL and associated structures (Johnson 1965). MRI

can detect sensitive inspection of the integrity of the

ligament, as well as detection of other concomitant

injuries to menisci or cartilage. MRI is reliable,

though costly, and not yet widely available to all

practices (Smith, 2020). Other imaging modalities

include ultrasound and x-ray. X-rays, though they

don't directly visualize the ACL, are useful in ruling

out fracture or avulsion injury. Ultrasound is not so

commonly utilized but can provide dynamic

evaluation of ligamentous structures when performed

by skilled operators (Patel 2018).

Table 2. Diagnostic methods and their clinical

effectiveness.

Method Sensitivity (%) Specificity

(

)

Lachman Test 85-95 85-95

Anterior Drawer

Test

70-90 70-90

Pivot-Shift Test 60-80 90-98

MRI 86-95 80-95

3 TREATMENT MODALITIES

The treatment of ACL injuries depends on several

factors, including the degree of injury, the level of

activity of the patient, age, and personal goals.

Treatment can be broadly classified into surgical and

non-surgical interventions (Davis 2017).

Operative repair is generally recommended for

those with complete ACL tears who are willing to

regain high level physical function (Johnson 1965).

Arthroscopic ACL reconstruction is the most

common type of surgery in which the compromised

ligament is replaced by a graft. Either autografts

Treatment Methods for Anterior Cruciate Ligament (ACL) Injuries

449

(tissue harvested from the patient) or allografts (donor

tissue) can be utilized as grafts (Wang, H,2019).

Table 3. Comparison of autograft vs. Allograft in ACL

reconstruction.

Feature Auto

raft Allo

raft

Source Patient’s Own

Issue

Donor Issue

Healin

Faste

Slowe

Risk Of Rejection None Low To

Moderate

Donor Site

Morbidit

Present None

Reo

eration Ris

Lowe

Sli

htl

Figure 2. ACL reconstruction outcomes by graft type (1-

year follow-up).

Autografts Are Typically Harvested from The

Quadriceps Tendon, Hamstring Tendons, Or Patellar

Tendon. Each Graft Is Associated with Both

Advantages and Disadvantages. (A. Todor 2024).

Patellar Tendon Grafts Are Robust and Provide Good

Fixation but Are Associated with Anterior Knee Pain.

Hamstring Grafts Are Less Invasive to Harvest but

May Result in Slightly Weaker Early Fixation.

As figure 2 shown, allografts obviate donor site

morbidity and reduce operating time but may have an

increased likelihood of graft loss and delayed

incorporation (Kumar & Singh 2016) in figure 2, it

shows the process of ACL reconstruction by graft

type, graft choice is based on patient concerns,

surgeon preference, and specific functional demand

(Davis 2017). Another consideration in surgical

technique is whether to use single-bundle or double-

bundle reconstruction. (Filbay, Grindem 2019). The

single-bundle technique reconstructs the

anteromedial bundle of the ACL, while the double-

bundle technique attempts to more closely replicate

the native anatomy by reconstructing both the

anteromedial and posterolateral bundles (Mitchell

2021). While the double-bundle technique might

offer improved rotational stability, it is technically

more demanding and time-consuming. Non-surgical

treatment may be applied to patients with partial tears

of the ACL or those with minimal functional demands

(Robinson 2019). Treatment is typically physical

therapy that makes the supporting musculature

stronger, increases proprioception, and enhances

neuromuscular control. Brsing can impart external

support for the knee for physical activity though its

long-term efficacy is questioned. Modification of

activity to avert the causative factor tends to reduce

recurrence. (a. Todor 2024). For most patients,

conservatively, including those not partaking in the

pivoting sporting activities, satisfying results may

occur. More recent therapies such as biological

injections are also being explored. Platelet-rich

plasma (prp) and stem cell therapy are trying to

enhance healing by delivering growth factors to the

location of injury. (Chen, 2021) although early

reports are promising, larger clinical trials need to be

done to establish their efficacy and safety (Jappelli, R

1997).

4 REHABILITATION AND

DIGITAL THERAPY

Table 4. Phased postoperative rehabilitation timeline.

Phase Duration Focus

Phase I 0-2 Weeks Pain Control,

ROM Recover

Phase II 2-6 Weeks Muscle

Strength,

Wei

ht Bea

Phase III 6-12 Weeks Balance

Phase IV 3-6 Months Functional

Training

Phase V 6+ Months Return To S

ort

Figure 3. wearable sensors and gait symmetry tracking

during rehab.

Rehabilitation is the cornerstone of effective

management of ACL injury. Regardless of whether

the treatment is surgical or non-surgical, formal

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450

rehabilitation is essential for return of function,

prevention of re-injury, and return to activity. As

table 4 shows, rehabilitation postoperatively typically

follows a staged approach. Pain management,

reduction of swelling, and restoration of range of

motion passively are the focus of the initial phase.

Strengthening exercises, especially of the quadriceps

and hamstrings, become important as healing

progresses. Training in balance and proprioception is

established to further enhance joint stability. The

advanced stages of rehabilitation involve sport-

specific training, agility drills, and endurance.

Return-to-sport standards usually consist of adequate

strength and flexibility, passing of functional tests,

and mental readiness. (A. Todor 2024). The entire

rehabilitation process could take six months to one

year based on individual progress and severity of

injury (Brown, 2020) digital health technologies are

transforming rehabilitation. Wearable sensors,

mobile apps, and tele-rehabilitation platforms are

being used more and more in recovery programs.

They offer real-time feedback, monitor patient

progress, and increase engagement. As figure 3

shows, wearable sensors can monitor movement

patterns, detect departures from standard

biomechanics, and alert clinicians to intervene.

(Filbay, Grindem 2019). Cellular apps give patients

exercise routines, reminders, and tracking. Patients

also notify their therapists, making it more convenient

and personalized. Gamification and virtual reality are

emerging as new methods of increasing patient

motivation and compliance. These interventions

make rehabilitation interactive and fun, which is also

essential for young patients. Secondly, data obtained

from virtual sites can be employed to calibrate

treatment strategies, predict recovery pathways, and

identify risk patients with poor outcomes (Brown

2020). This evidence-based approach maximizes

evidence-based practice and enhances the provision

of care (A. Todor 2024).

5 CONCLUSIONS

Injuries of the ACL are a significant concern in sports

medicine and orthopedics. They affect a wide

population of people and have profound effects on

quality of life, mobility, and joint health in the long

term. Accurate diagnosis, tailored treatment planning,

and close rehabilitation are paramount to optimal

outcome. Surgical reconstruction remains the gold

standard in active patients with full thickness ACL

injuries, and non-operative treatment is applied to

selected patients who are of low demand. The

treatment would have to be tailored according to the

nature of injury, patient needs, and likelihood of

complications versus benefits. Rehabilitation is a key

factor in recovery, and the incorporation of digital

technologies opens up new directions for enhancing

its effectiveness. The future of research may include

developing new advanced biological therapies,

enhanced personalization of rehabilitation regimens,

and digital tool extension applications. Last, a

multidisciplinary approach coupled with surgical

competence, physiotherapy, and technological

innovation is the most likely to yield a successful

future for those who suffer ACL injury. A continuous

collaboration of clinicians, researchers, and patients

will promote advances and improve results in the care

of ACL injuries.

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