Anterior Cruciate Ligament (ACL) Rehabilitation

Introduction

The anterior cruciate ligament (ACL) is a key structure in knee kinematics as it resists tibial anterior translation and rotational loading. The ACL provides approximately 85% of the total binding force of anterior translation. It also prevents excessive medial and lateral tibia Rotation and varus and valgus stress [1]. Nevertheless, due to the presence of mechanoreceptors in the ligament, its main role is proprioceptive function [2]. Therefore, ACL injury may be considered a neurophysiological dysfunction rather than a simple peripheral nerve injury. Musculoskeletal injuries. [3][4] Due to its complex role in knee kinematics in the event of an ACL injury, clinical symptoms and subjective instability are present, thus requiring a comprehensive rehabilitation program [5]. ACL injury is a relatively common knee joint Athletes[6] and women are two to eight times more likely to be injured than men[7][8].

The injuries can range from mild (such as small tears/contusions) to severe (when the tissue is completely torn)[9]. If there is a complete ACL tear and there are clinical and psychological signs of instability, surgical reconstruction is necessary. But it is not necessarily obvious that ACL Reconstruction will automatically return them to pre-injury levels of activity.

ACL reconstruction is elective between conservative and surgical procedures.

Please see these pages for related ACL Injuries

Clinically Relevant Anatomy

Knee anatomy

The anterior cruciate ligament (ACL) is a strong connective tissue that runs from the hip joint to the hip joint. The ACL arises from the posteromedial corner of the medial aspect of the lateral femoral condyle in the intercondylar notch and is anteriorly inserted into the intercondyloid eminence of the tibia fusing with the anterior horn of the medial meniscus. The ACL advances medially and distally across the joint as it moves from the femur to the femur. When that happens it turns in a slight outward (sideways) curve.

The thickness of the blood vessels in the arteries is not uniform. In the ACL there is an avascular zone in the fibrocartilage of the anterior portion where the ligament faces the anterior rim of the intercondylar fossa[10]. Spontaneous abnormalities and the presence of a fibrocartilage is also found in gliding tendons in areas where compressive loads are applied play a role in the poor healing of the ACL.[11]

Please see these pages for relevant anatomy: Anterior Cruciate Ligament (ACL) and Anterior Cruciate Ligament (ACL) – Structure and Biomechanical Properties

General Considerations

ACL rehabilitation has changed considerably over the past decade. Intensive research on the biomechanics of injured and operated knees has led away from the early 1980s in delaying weight bearing and Range of motion (ROM) limitations of current early rehabilitation programs, namely immediate ROM training and weight bearing exercises [5].

ACL rehabilitation is suitable for both conservative and surgical treatment. Conservative treatment of ACL injuries may be the best option for sedentary patients. Indeed, the most important symptoms of subjective instability in physical activity and activities of daily living should be considered when the patient is older Deciding for or against ACL reconstruction [12][13]. In these cases, a physical therapy program to fully regain ROM, a comprehensive program to strengthen and restore proprioception, and normal gait pattern training may be the best rehabilitation option. However, if symptoms are unstable The knee was not reduced after physical therapy, and ACL reconstruction was not recommended after adjusting activities. This may prevent multiple interventions due to further meniscus and cartilage damage [14].

ACL tear

It is useful to remember that ACL injuries rarely occur alone. The presence and extent of other injuries may affect how an ACL injury is managed. In fact, the mechanism of injury can also damage the medial collateral ligament (MCL) or meniscus. other related injuries May be microfracture or bone contusion with or without cartilage damage. [15][16] In these cases, ACL rehabilitation programs must not be standardized and take into account comorbidities.

The main goals of general rehabilitation for an ACL injured knee are:

• Gain full ROM of the knee
• Restoring muscle strength and proprioception
• Gaan in good functional stability
• Reach optimal functional level (walking run jumping…)
• Decrease the risk for re-injury
• (Return to sport)

Phases of ACL rehabilitation

Physiotherapy interventions can be broken down into several phases:

1. Acute Stage
2. Preoperative stage or conservative treatment
3. Post-surgical Stage
4. Return to sport

Acute Stage

After an ACL injury, with or without surgery, physical therapy focuses on restoring motor strength, proprioception, and stability. PRICE or PEACE AND LOVE should be used in the acute phase to reduce swelling and pain to try a full range of Exercise and reduce joint effusion. Use appropriate anti-inflammatory medications to help manage pain and swelling [5].

Indications for the use of crutches and eventually a knee immobilizer may be appropriate for some patients. However, prolonged use of the knee immobilizer should be limited to avoid quadriceps atrophy [14].

Neuro-muscular inhibition of the quadriceps caused by intrarticular effusion may have a negative impact on strength. In any case, exercises should encourage range of motion initially strengthening the quadriceps and hamstrings and eventually proprioception[5][14]. Of course strength is proprioceptive changes occur in both injured and uninjured limbs[17]. To aid pre-operative optimization, the following guidelines are recommended for acute and early sub acute stages post injury:[18][19] [20]

• Full extension is obtained by doing:
  1. Passive knee extension: a physiotherapist can provide full passive knee extension through manual therapy and instructional exercises that add leverage to force gentle extension
  2. Patellar self-mobilisations,
  3. Heel Props,
  4. Prone hang exercise,
  5. Static quads/SLR;
• Bending (Flexion) is obtained by doing:
  1. Passive knee bend: the physiotherapist can provide full passive knee flexion through manual therapy and instructional exercises that add leverage to force gentle flexion
  2. Prone Knee Bend (Gentle Kicking Exercise)
  3. Wall slides,
  4. Heel slides;
• Knee flexion/extension in sitting;
• Ankle DF/PF/circumduction;
• Glutes medius work in side lying;
• Gluteal exercises in prone;
• Weight transfer (forward/backward/sideways) while standing.

Neuromuscular Electrical Stimulation (NMES) combined with exercise has also been shown to be more effective in improving quadriceps strength than exercise alone[21].

It may also be useful to consider taping to stabilize and encourage reduced inflammation[22].

There is no clear transition from the Acute stage to the Pre-operative stage any stage may take some days or months before surgery. Didactically the end of the acute stage occurs when the patient regains full knee motion in extension and at least 110 degrees flexion or gait almost normal.

Before Surgical Stage

IF ACL Surgery IS PERFORMED WHEN THE KNEE IS VERY PAINFUL AND NOT COMPLICATED IT IS DIFFICULT TO PERFORM ACL SURGERY WITH A RED THROAT.

The risk of postoperative knee stiffness can be greatly reduced if surgery is delayed until the acute inflammation has passed with the inflammation subsiding to normal or near normal range of motion (especially extension) and gait is achieved it is worth doing have been restored[23]. But the actual guidelines[14] [5]agree that the implication of reconstruction is constant instability of the knee with complaints that it allows. This disease is difficult to diagnose in an acute setting. The guidance recommends that an ACLR should not be conducted in. first weeks after trauma in order to reduce the risk of operating on an asymptomatic patient.

As soon as the Acute Stage is over it is important to prepare the knee for surgery as much as possible to optimize the outcome. The focus should be on strength and proprioception. Despite this the physiotherapist should keep the injured knee in a comfortable position to improve its range of motion minimal inflammation.

RICE and electrotherapy can be used in the several weeks prior to surgery in order to achieve full range of motion and reduce joint effusion. The patient must also have a normal gait pattern: for that reason it is useful to analyze leg movements both in the swing phase of walking and in the one-legged half-stand . It will therefore help the patient to regain speed and recovery after surgery[24].

The length of time before this procedure can last a few days or several weeks. For this reason the physiotherapist’s role is also to maintain the patient’s compliance. For this reason the rehabilitation program should have measurable weekly goals to improve muscle strength and conditioning to develop range of motion and improve proprioception. This will result in additional goals to be achieved each week: treatment compliance will be maintained by the patient achieving these goals[25].

On the pre-operative phase it is important to provide a different approach to strengthening muscle strength and proprioception. For that reason it can be a good solution to offer the patient two separate exercise programs to do in the gym and at home. But it is very important that you give it injured knee sub-maximal loads to avoid knee swelling or re-injury due to lack of proprioception.

1. Obtain and mantain full range of motion in extension and continue to improve range of motion in flexion with minimal swelling;
2. Build muscle strength: Once you hit the 110-degree mark, work may begin to build muscle strength. Examples of exercises are:
   • Swimming (avoid breaststroke),
   • Easy exercise equipment like elliptical cross-trainer Stationary Bicycle and treadmill
   • Leg press machine,
   • Leg swing machine or Leg Extension machine (see Open-Kinetic-Chain below) .
   • Weight-bearing exercises such as squats lunges steps up (see Closed-Kinetic-Chain exercises below);
3. Improve proprioception:
   • One-leg- standing exercise
   • Includes single leg standing exercises that offer balance cushions or cues for the hands (throw or catch a ball reaching targets…)
   • Single leg standing exercises in different planes (frontal sagittal) .
   • Preparation for controlled jumps;
4. Increase compliance with the rehabilitation program[25];
5. Psychological preparation: The patient must know what to expect from the surgery and understand the stages of postoperative rehabilitation.[18][26]

After Surgery

Please see this page for ACL Rehabilitation: Acute Management after Surgery related

ACL Reconstruction has undergone tremendous changes in the last decade.Different tissues/grafts have been used to physically reconstruct the torn ACL. The most commonly used are autografts (patellar bone & hamstring) and sometimes allografts (taken from cadavers). Process of ligamentization of the need to be careful about load and physical requests.[27] However, reconstructing the new ACL seems to be indicated as a process that lasts 9 years or more. Moreover it appears to be a process of revision rather than complete rehabilitation.[28] Despite this, there is there is no significant difference in physiotherapic approach in After Surgery Stage between grafts.

Consider pain, swelling, muscle contractures, restricted range of motion, and abnormal gait patterns as indicators of a good outcome. In the postoperative phase, three factors are important:

1. Early knee extension equal to opposite side
2. Early weight bearing,
3. Closed and open kinetic chain strengthening exercises.

Early knee extension provides the foundation for the entire rehabilitation program.

The incidence of knee flexion associated with quadriceps weakness and extensor mechanism dysfunction after ACL reconstruction is significantly reduced with rapid knee extension immediately after surgery.

According to the ACL Rehabilitation Guidelines, a good physiotherapeutic program is based on achieving weekly goals.

Week 1

• Routine icing and elevation are used to reduce inflammation[29][30][31]. Eventually medication or pain management as directed by the MD in an attempt to rehabilitate goals.
• Aim for full extension and 70 degrees of flexion by the end of the first week.
• Agree with your surgeon and use knee braces and crutches only when needed. In fact, wearing a knee brace after ACL reconstruction has no additional therapeutic value [32]. The author gradually reduced the use of knee pads. [24][19] Postoperative rehabilitation brace [33] Expanding or opening the hinges for the ROM did not provide a significant advantage. [33] The necessity of postoperative functional bracing and the consensus regarding the duration of the bracing have been questioned in many rehabilitation protocols. Harilainen et al. compared Effect of functional bracing versus postoperative unbracing after ACL reconstruction with patellar grafts. There were no significant differences in functional outcome stability or isokinetic muscle torque between the two groups at 1 and 2 years postoperatively [34]. in similar The study by Risberg et al. found no significant differences in knee laxity, exercise muscle strength, functional knee tests, or pain extent. [33]
• At least 8 weeks of multidirectional movement of the patella should be included. Additional mobilization exercises for the first 4 weeks are passive extension of the knee (without hyperextension) and passive and active mobilization of flexion.
• The strengthening exercises for the calf muscles, the hamstrings and the quadriceps (vastus medialis), can be done lying on the back or on the stomach.
• Isometric quadriceps exercises are safe from the first postoperative week [35]
  Early weight bearing appears to be beneficial and can reduce hip pain. Early movement is safe and can help avoid later complications of arthrofibrosis. Continued passive movement is not warranted to improve rehabilitation outcomes in patients. Minimally supervised physical therapy in paw stimulating patients appears to be unsafe without a significant risk of complications[5].

ACL Reconstruction: Rehab Dwumadi Nhyiam[36]Heel Raises Ma ACL Reconstruction[37]

Week 3-4

• There is no evidence that icing and elevation are beneficial after 1 Week.
• The first goal is to maintain full expansion and increase the amount of turnovers each week.
• Try really adding to the standing phase, try walking with one crutch. Cane use can be reduced earlier with good hamstring/quad control.
• Strengthening exercises for the calf muscles, the hamstrings and the quadriceps (vastus medialis), can be done seated on a stationary bike or with light weights. Progression of movement depends on painful swelling and quadriceps control.
• Starting eccentric quadriceps training (in CKC) from 3 weeks after ACLR is safe and contributes to greater improvements in quadriceps strength than concentric training[38].
• In a patient with good hamstring/quadriceps control it is possible to actually attempt Closed Kinetic Chain exercises (half-squats hip hinges calfs step up…). These exercises are usually done by patients who have trained for a long time in a good preoperative program.

Stretching and bearing weights early on builds quadriceps strength. The combination of early knee extension, early weight bearing and closed dynamic quadriceps strengthening allows patients to complete the postoperative recovery period fairly quickly without requiring Damage to ligament stability. [18]

Week 5

• Passive mobilization should normalize movement, but flexion should not be complete.
• Hamstring and quadriceps strengthening can begin at higher intensities with both open-chain and closed-chain exercises. Exercises should start at a light intensity (50% of maximum strength) and now gradually increase to 60-70%. Closed chain exercises should start with irresponsible people position (leg press step) to a more crowded starting position (ex.squad). Progression of movement depends on painful swelling and quadriceps control.
• Proprioception and coordination exercises can be converted if overall strength is good. This includes balancing exercises on boards and tolls.

Postoperative phase 1 ( 1-5 weeks)

Possible examples for exercises to teach self-mobilizations of the knees and strength of the quadriceps and hamstrings:

Week 1: Self-mobilization [39] Week 3: Strength training and gait training [40] Week 5: Strength training [41]

Week 10: Forward-to-Back Lateral Dynamic [42]Week 12: Forward-Back Lateral Dynamic [43]Week 15: Sprint Jump Cuts [44]

Week 10

• The loaded process is the basis from now on.
• Proprioception and coordination exercises can be more specifically tailored to a patient’s individual motor needs. If the patient does not want to return to sports, these exercises can meet his ADL needs (climbing stairs, walking uphill or downhill skating, swimming…)
• Can include forward-backward and lateral dynamic motion as well as isokinetic motion [19].

Month 3

• After 3 months the patient can move on to functional exercises such as running and jumping.
• As proprioceptive and coordination exercises increase in intensity, there is a rapid change in direction. In order to stimulate coordination and control by afferent and efferent information processing exercises, it should be enhanced by changes in the visible input surface stability (trampoline) speed of exercise performance complexity of the task resistance one or two-leg performance and so on.[19].

Month 4-5

• The ultimate goal is to improve the endurance and strength of the knee extensors for better muscle control through plyometric exercises and with sport-specific exercises added to the.
• Differences in speed and deceleration during sprinting and turning and passing improve arthrokinetic reflexes to prevent further trauma during competition.[20]

Return to Sport

ACL injury can lead to static and functional instability, which can lead to changes in movement patterns and increase the risk of osteoarthritis. In many cases, an ACL injury can end an athlete’s career prematurely. [45]

ACL Return to Sport: Hop Test|[46]

Inadequate strength and power after surgery can be a risk factor for future injury and can set athletes back from trying to return to previous levels of performance. Researchers suggest that a surgically repaired leg should function at least 90% as well as your previously uninjured leg Return to sport [47]. The three jump test can be used as part of a comprehensive physical and functional exam to help ensure not only a quick but safe return to sport after an ACL reconstruction. These 3 tests are sensitive enough to measure left-right differences and can be used during A more advanced recovery phase after surgery to help ensure that the athlete’s exercise program successfully restores the injured leg to at least the level of the uninjured leg [47].

Athletes undergoing ACL reconstruction should be informed that participation in Class I sports postoperatively increases the 2-year knee reinjury rate more than fourfold. A later return to class I movement and the more symmetrical quadriceps strength prior to recovery significantly decreased this ratio [48].

Mechanisms of previous injuries can guide the final stages of rehabilitation as strength and conditioning develop: ACLR due to indirect injury mechanisms can focus on ankle-knee-hip coordination exercises or core stability or sport-specific posture .

Please see these pages for Return to Play in Sports related

Open versus Closed Kinetic Chain Exercises

Closed kinetic chain exercises (CKC) and Open kinetic chain exercises (OKC) play an important role in recovering muscle (quadriceps hamstrings) strength and knee function.

• CKC exercises became more popular than OKC exercises in ACL rehabilitation. Some physicians believed that CKC exercises were safer than OKC exercises because they placed less strain on the ACL graft. Besides it was also believed that CKC exercises are as great and effective as OKC exercises. Bynum et al. (1995) conclude that CKC exercise is safely effective and sacrifices some important advantages over OKC exercise. [49] .
• A study comparing the amount of anterior tibial displacement in the ACL-deficient knee during (1) resisting knee extension an OKC-exercise and (2) parallel squat with the CKC-exercise concluded that the ACL-deficient knee has significantly greater anterior tibial displacement during extension from 64° to 10° in knee extension exercises compared to parallel squat exercises[50].
• In one study, however, no difference in stress was found on the intact ACL between OKC and CKC exercises[51].
• Current ACL grafts can behave much like the intact ACL. It is therefore suggested that both types of exercise can be performed safely[19].
• However a study that investigated the effects of OKC and CKC exercises on functional function concludes that both OKC and CKC regimens result in equally good long-term functional outcomes[52].
• In another study, group 1 underwent quadriceps strengthening with CKC alone, while group 2 received CKC training and OKC exercises from postoperative week 6 [53] which appeared to increase OKC quadriceps after ACL reconstruction. Muscle training resulted in significantly stronger quadriceps, whereas no Knee stability was reduced at 6 months and also resulted in more athletes returning to previous activities earlier and at the same level as before the injury. The authors concluded that the combination of OKC and CKC exercises was more effective than CKC exercises alone [54].
• The use of bone-patella-tendon-bone autografts was more likely to cause anterior knee pain than the use of hamstring autografts. Therefore, the type of autograft can guide the physical therapist in selecting the correct period to insert the OKC sitting leg extension. will be earlier than In the case of hamstring muscle transplantation, the status of patellar tendon transplantation one week later. Guidelines agree to insert OKC exercises within 4 weeks after surgery [5][14].
• In any case, it is important to follow the progression of loading on the knee so as not to cause pain or laxity. A recent systematic review of randomized controlled trials comparing OKC versus CKC exercise in post-ACLR patients [55] found that:
  1. No or insufficient evidence of differences between OKC and CKC in terms of pain scores or joint laxity
     • The former could be explained by (1) lack of sensitivity of the questionnaire used (2) statistical power of the analysis or (3) patients receiving OKC vs CKC actually did not differ in pain
  2. There is weak evidence for better knee extensor strength with open-chain exercises, and weak evidence for better active knee flexion with closed-chain exercises.

Open-Kinetic-Chain exercises:

Characteristics

• Non-weight bearing
• Motion occurring at a single joint: isolated motion that promotes more shear forces [50]
• Distal segment free to move
• Resistance is usually applied to the distal segment

Open Kinetic Chain Knee Extension Exercises

These exercises appear to have a controversial role in ACL rehabilitation programs, as several studies have shown that OKC extension exercises from 60° to 0° flexion significantly increase tibial anterior translation in ACL-deficient knees as well as reconstructed ACL graft strain Knee [24] Despite these findings, the OKC extension was not excluded from ACL rehabilitation programs because the same study showed that the OKC extension from 90° to 60° of flexion can be done safely without increasing tibial Anterior displacement or ACL graft Strain[24]

In short, OKC-extension exercises in ACL rehabilitation programs could be performed safely in ROM from 90° to 60° flexion and are further useful to train the isolated quadriceps.

Open-Kinetic-Chain Knee-Flexion exercise

OKC-flexion exercises play an important role in the rehabilitation process because examination showed no anterior tibial translation or ACL graft strain during this exercise. Besides they introduce isolated hamstrings muscles.[49]

Closed-Kinetic-Chain Knee exercises

Characteristics

• Weight bearing
• Movement at multiple joints: a compound movement that generally results in a tensile force[50].
• Distal part mounted on a surface: the end remains in constant contact with the immobile surface which is usually ground[56]
• Resistance can be applied both proximally and distally: all organs are loaded[56].

Closed-Kinetic-Chain Knee exercises

CKC exercises play an important role in ACL rehabilitation because they result in hamstrings-quadriceps co-contraction that reduces tibiofemoral shear forces. Apart from that, research showed that during CKC exercises body weight causes tibiofemoral joint compression which in turn reduces tibiofemoral shear powers .[50]

CKC apples have many advantages compared to OKC apples

• Increase knee joint stability (more joint tension) .
• Functional load
• Strong coordinative training
• Minimal shear force
• Less stress on the ACL
• Training throughout the expansion chain [57].
• No selective muscle training
• Weakest link in the chain is feeling the most overwhelming and correspondingly larger training types effect
• A few complications such as patellofemoral symptoms
• The CKC-apple is used earlier than the OKC-apple

Other Considerations

In a retrospective cross-sectional analysis by Culvenor et al.[58]. 30% of patients experienced patellofemoral pain (PFP) 12-15 months after ACLR using a hamstring graft. Those who were 27 years and older were 2.6 times more likely to report PFP. Patellofemoral cartilage lesions genital tears (both assessed by arthroscopy) preinjury activity level time from injury to surgery and sleep are not predictive of postoperative PFP.

Those with PFP did not reduce their movements but were significantly worse on hop distance and single-leg tasks. Patients also reported significantly lower quality of life with recurrence of negative sporting habits and increased kinesiophobia.

PFP is important to consider because inadequate fear avoidance regulation of movement perpetuates pain and functional disability through lower pain experience thresholds. The use of appropriate language during rehab and psychosocial interventions is recommended.