Dr. dr. Tirza Z. Tamin Sp.KFR (K)

Department of Physical Medicine and Rehabilitation, Cipto Mangunkusumo Hospital




Injury to the ACL is potentially functionally debilitating and often requires surgical intervention followed by an extensive course of rehabilitation. Approximately 200.000 ACL injuries occur annually in United States, leading to nearly 100.000 ACL reconstruction surgeries, which has expectations of excellent outcomes.1 Rehabilitation, as it applies to the recovery period from Orthopaedic Surgery, is a process that aims to enhance and restore functional ability to the affected limb or joint. The first tenet of this must be to do no harm, hence, as this applies to ACL reconstruction, the aim is to try and restore full function, over a period of time, without damaging or loosening the graf. 2

The initial aim is to get through the first 6 – 8 weeks with a graft that remains tight, but with near full extension of the knee, and minimal swelling. This implies a good deal of rest, to allow the knee joint to recover and to allow the swelling to go down, yet whilst maintaining extension (getting the knee straight). It does not imply exercise or strengthening work, all of which can loosen graft, and all of which can be worked on after the ends of the graft have healed into the bone (6 – 8 weeks for patella tendon, 10 – 12 weeks for hamstring tendon).2 The interest in the knee joint, particularly the anterior cruciate ligament (ACL) reconstruction has increased more and more, since the disease and its treatment is a challenge for many health care professionals connected to this thematic.3 4




II.1 Definition of ACL

The anterior cruciate ligament (ACL) is an intra-articular structure essential for the normal function of the knee. The ACL may be partially or completely torn. It also may be injured in combination with other structures, most commonly tears of the medial collateral ligament and medial meniscus.4

The ACL is a collagenous structure approximately 38 mm in length and 10 mm in width. The ligament arises from a wide base in the tibia anterolateral to the anterior tibial spine. It then traverses the knee in a posterolateral direction, attaching in a broad fan-like fashion at the posterolateral corner the intercondylar notch of the femur. According to Fu and collaborators, it is organized in two major bundles named after their insertion sites on the tibia. The anteromedial bundle, which tightens in flexion and is the longer of the two, controls anterior translation of the tibia on the femur. The posterolateral bundle, which tightens in extension and internal rotation, controls rotation.4


II.2 Rehabilitation

The ultimate goal of rehabilitation of sport specific injuries is maximal restoration of function for an anatomic area or a specific athletic activity. To achieve maximum efficiency of the rehabilitation process several goals should met: (1) establishment of a complete and accurate diagnosis; (2) minimization of the deleterious local effects of the acute injury; (3) allowance for proper healing; (4) maintenance of other components of athletic fitness; (5) return to normal athletic function. Adverse Effects of Immobility (Unilateral Limbs Suspension or Absolute Bed Rest): (1) Muscle atrophy and loss of strength (2) General deconditioning (3) Structural changes of articular capsule connective tissue, causing decrease range of motion (4) Articular cartilage degeneration (5) Cardiovascular deconditioning (6) Reduced stimulus of bone mineral depositing, possibly contributing to diminished bone density.5


II.2.1 Establishment of a complete and Accurate Diagnosis

Without a through diagnosis, adequate rehabilitation is not possible. The specific tissue damage must be identified, yet this may only partially define or even completely omit the tissues that were overloaded to cause the injury, especially in the microtrauma process. The clinical symptom complex comprises the presenting complaints. Specific inflexibilities, weaknesses, or imbalances (functional biomechanical deficits) and the substitution pattern (subclinical adaption complex) can be identified if the patient and the athletic activity are considered in the context of the injury.5

Stages of Rehabilitation


 II.3. Cause of ACL Rupture

The most common cause of ACL rupture is a traumatic nearly always due to hemarthrosis. An ACL rupture is present in 75% of patients presenting with an acute hemarthrosis and is due to bleeding from vessels within the torn ligament. Differential diagnoses include osteochondral fracture, peripheral meniscal tear, retinacular tear associated with patella dislocation or subluxation, PCL tear or bleeding disorders.6

II.4 Pre-reconstruction exercise

The importance of Pre-Reconstruction Exercise: (1) Control pain and swelling (2) Return ROM to normal and decrease the risk of post-operative stiffness (3) Develop muscle strength and balance sufficient for normal gait and ADL (4) Maintain fitness in preparation for surgery (5) Mentally prepare the patient for surgery. Keays et al. reported on the beneficial effects of a 5-week home-based exercise program for improving quadriceps strength and knee function early post-ACLR injury. Based on the study Eitzen et al. the preoperative quadriceps strengthening may be a significant predictor of knee function two year after ACLR. Preoperative deficits in quadriceps strength of greater than 20% have been associated with significant persistent muscle weakness two years after ACLR.7

Knee extensor strength deficit following ACLR is a common problem which has been reported in previous studies. In a recent review of the literature, studies including research by Palmier-Smith et al., reported knee extensor muscle strength deficit, ranging between 24% and 40.5%, 6 months after ACLR, while another 10 studies reported a residual, deficit in quadriceps strength of 10% to 27%, 12 months after ACLR. Furthermore, long-term negative outcomes of strength deficits on knee function for sports activities and even during daily activities. Thus, the recovery of quadriceps muscles strength is one of the most important factors after ACLR.7

II.5 Post-reconstruction exercise

The major goals of rehabilitation program. The major goals of rehabilitation following ACL surgery are:6

  • Restoration of joint anatomy;
  • provision of static and dynamic stability;
  • maintenance of the aerobic conditioning and psychological well being; and
  • early return to work and sport.

These have required the development of an intensive rehabilitation program in which the patient has to take an active involvement. The graft undergoes physiological changes during its incorporation, as fibroblastic activity changes the biology of the graft to become more ligamentous. The graft is weakest between six and twelve weeks post operatively so programs must be designed to protect the graft during this period.6


II.5.1 Program Design

1) The union of the graft into the bony tunnels occurs by 6 – 8 weeks with a patella tendon construct and by 10 -12 weeks with a hamstring tendon construct. This junction is more likely to be broken down by high repetition of moderate loads rather than one particular incident. Care must be taken in this period therefore, Dr Keith Holt to avoid activities that load the ligament excessively and repetitively. Activities such as walking are more likely to damage a graft than a fall. This is because each step, particularly during the phase when the leg is extended out in preparation for the next step, and at the start of the next phase when it impacts at heel strike, leads to a sudden rise in the tension within the graft. This means that there is a pulling on the ends of the graft with each step which, if performed often enough, will lead to a gradual loosening of the graft. For this reason, crutches are used for the first 4 – 6 weeks. They reduce the number of steps taken, and should be used full time for the first two weeks, and thereafter for any longer walks (outside the house) up until the 4 – 6 week mark. Less steps means that the graft is pulled on less, and hence, is less likely to loosen.2

2) The graft is dead and must undergo a process of revascularisation whereby a new blood supply grows into it. As the ends heal into the bone, new blood vessels start to progress down the graft. They initially appear on the surface, but eventually move into the depths of the graft as well. This process begins as early as the first week, and continues to occur out until about 18 months. Even then, small changes continue to occur within the graft such that, according to some authors, it is not fully mature until about 3 years post surgery. However, by 9 months, most of the changes have occurred, and hence, a good percentage of people are starting to return to sport by about this time.2

3) The dead collagen cells in the graft must be slowly replaced by new living cells so that the graft is functional again. The new collagen is type 4 and comes from the synovial lining tissue of the joint. It is not type 1 like the original ligament, and hence, no graft is ever as strong as a normal ligament. Nevertheless, the injury rate to the other knee remains higher (in most studies) than the re-injury rate to the same knee, and this is thought to be due to the fact that a good number of injuries occur in individuals who have weaker than normal ligaments in the first place. Because of this, and because the re-injury rate (overall 5% but higher in younger individuals) is compatible with the introduction and return to twisting and turning sports, if adequate recovery time is allowed, return to previous types and levels of sport is allowed.2

4) Graft ‘stretch-out’ is a phenomenon that occurs, usually in the first 4 months. It most probably represents either a gradual failure of fixation, or sequential graft fibre failure, rather than actual stretch out. Sequential fibre failure probably occurs because of rupture of the tightest fibres with repetitive load and, once these have ruptured, the next tightest fibres are at risk. By 4 months this seems to be less of a problem, probably because of increasing graft strength, and possibly because of a remolding of the fibres within the graft. Repetitive impact loading activities, such as running, may therefore begin at about this time. Our experience over the years, where different protocols have been tried and observed, is that running at 3 months may cause some graft loosening, but by 4 months this is uncommon.2 9

5) Return to sport requires a successful surgical outcome and a return of confidence in the knee. Return of confidence is an individual phenomenon which probably relates to the return of proprioception: that being a knowledge of where the knee is in space. The original ACL contains nerves and sensors that tell the brain where the knee is in space, and what it is doing. The graft does not have these nerves and sensors in it, and it seems that the recovery of this sensation relies on the rest of the knee picking up the slack. This takes time, and it seems to be different in each individual; albeit that full recovery, where upon the knee feels normal again, does not usually occur until about 15 months post surgery. Interestingly, proprioceptive recovery does not seem to correlate to the degree of clinical success of the procedure: that is, how stable the knee feels when examined. Things that help recovery are: time, training and proprioceptive aids (such as a soft tissue knee brace that pulls on the skin to provide increased feedback). Without sufficient recovery, as judged by a return of confidence in the knee, actual sport (competition sport as against training) should not be undertaken.2

6) The literature contains many rehabilitation protocols. A good many are motivated by the thought that more aggressive rehabilitation leads to an earlier return to sport. Whilst this has been demonstrated in some studies, experience would suggest that the safe time to return to sport, a time when proprioception is adequate, is still around the 9 month mark. In addition, the very few papers that have looked at minimal therapy in the early weeks (not no therapy, but rather a self guided program to maintain range whilst protecting the graft), suggest outcomes compatible with the more aggressive protocols. The swelling settles more quickly, the knee motion is regained more easily, and the risk to the graft is less.2

7) The type of ACL graft is important. Many of the rehabilitation protocols, including the so called ‘Accelerated Rehabilitation’ protocol of Shelbourne, were designed for open surgery using patella tendon grafts. Firstly, with open surgery, there is a need to overcome the pain of the procedure just to regain range. Such pain is then, in itself, self protective of the graft, however, the down side is that this limits the ability to regain a good range of motion in the early weeks. Hence, to some extent, these protocols have less application in arthroscopically aided procedures that are inherently less sore, and where pain may not be sufficient to lead the patient to overly protect the knee. Secondly, and perhaps more importantly, these protocols were developed for the use of patella tendon grafts which, by their very nature, allow for stronger fixation to the bone compared to a hamstring graft. This means that, in the first 6 weeks or so, a hamstring graft needs more care and protection than does a patella tendon graft. It can be seen therefore, that rehabilitation in the first 2 – 3 months is slower for a hamstring graft than for a patella tendon graft.2

8) No one protocol is satisfactory for all players and any adapted protocol should be used only as a guideline for comparing an individual with the average. Every player will have his or her own set of problems, and most will need individual attention from a physical therapist at some point.2

Post Reconstruction Rehabilitation Phase:2

  • Early Post Operative Phase (Days 1-14) In this phase the goals are; (1) Restore full passive knee extension; (2) Diminish joint swelling and pain; (3) Partial weight bearing on crutches when walking.
  • Mid Post-Operative Phase (Weeks 2-6) In this phase the goals are: (1) Minimize swelling; (2) Maintain some fitness without stressing the knee; (3) Begin to walk normally
  • Late Post Operative & Early Exercise Phase (Weeks 6-12) In this phase the goals are: (1) Increase strength; (2) Proprioceptive work; (3) Preparation for next stage
  • Strength and Recovery Phase (Month 3-6) In this phase the goals are: (1) Focused strength work; (2) Advanced proprioceptive work; (3) Running; (4) Sport specific activities
  • Sport Specific Training and Preparation to Play Phase (Month 6-9) In this phase the goals are: (1) Improve fitness; (2) Improve strength; (3) Improve proprioception; (4) Return to sports training
  • Return to Sport Phase. In this phase the goals are: (1) Begin actual sport not just training; (2) Continue to train knee.

Post-operative rehabilitation is essential in optimizing your function and return to sport after an ACL reconstruction. The process of returning to physical and athletic activities is not based on time, it is based on the individual’s ability to achieve certain milestones or criteria. The time needed to do this will vary from individual to individual. Post-operative rehabilitation begins the day after surgery.2

During the first phase of rehabilitation, the goals are to increase your range of motion and strength, and return to walking without crutches. You can decrease swelling by elevating your knee above your heart, icing your knee with the cooling unit, using compression wraps on your leg and avoiding too much activity the first few weeks after surgery. As pain and swelling decrease, you will begin more specific strength training exercises in Phase 2. During this phase it is still important to monitor the return of any pain or swelling. Phase 2 will also focus on restoring your strength and proprioception.

Proprioception is a sensory modality that provides internal feedback solely on the status of the body’s position, movement and alignment. Various balance exercises will be used to help improve and recover your proprioception. These exercises also help to regain strength. In subsequent phases when jumping, cutting and pivoting are emphasized, it is essential that the body is in correct alignment.

One primary goal of Phase 3 is to eliminate strength differences between both legs. You will be doing strenuous strength training exercises three to four times a week. Often times it may be necessary to do more sets and repetitions on the surgical leg than the non-surgical leg to eliminate the difference. You must also be careful not to compensate or “overuse” the non-surgical leg while doing your strengthening exercises, as this will have the reverse effect on the difference. During this phase your physical therapist or athletic trainer will also begin to introduce running, agility and impact (jumping) exercises.

Phase 4 of rehabilitation is termed “athletic enhancement”. This is the phase where you will work on sport-specific movement drills. Although you will perform some exercises and movements from earlier phases, you will be working on doing these activities at higher speeds until you progress to game speed. Conditioning drills for muscular endurance and cardiovascular conditioning are included in this phase. Being released to return to sport is a collaborative decision between your surgeon and physical therapist or athletic trainer. They will use a series of tests to help determine your readiness for sport, including a computerized strength test (Biodex), a series of hopping tests, a shuttle run and a balance test. The chance of re-tearing your ACL after surgery is 5-15%.


II.5.2 Return to Sport

The International Knee Documentation Committee Subjective Knee Evaluation Form and hop tests have been advocated. Our criteria for return to play are outlined in TABLE 2. The athlete must also demonstrate sufficient confidence in the affected extremity to successfully return to sport without any fears or limitations. Finally, we only return the athlete to sport participation once the knee has returned to its normal state and reached the level of homeostasis described by Dye and Chew. If the patient’s knee is still sore or exhibits swelling after running, stiffness, or localized pain, the activities are reduced to a level that does not produce these effects.1



II.6 Knee Injury and Osteoarthritis Outcome Score (KOOS)

KOOS consist of 5 subscales; Pain, other Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport/Rec) and knee related Quality of life QOL. The last week condition is taken into consideration when answering the question. Standardized answer option are given (5 Likert boxes) and each question gets a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale. The result can be plotted as an outcome profile.2

II.7 Prognosis

According to Wilk et al (2012), generally the patient should exhibit 0° to 90° of knee ROM 5 to 7 days after surgery and 0° to 100° of knee ROM 7 to 10 days after surgery. In the study of Brewer et al (2000), it was obtained that adherence was related to statistically significant index of one-leg hop test in the rehabilitation after ACL reconstruction.1



  1. Wilk KE, Macrina LC, Cain EL, Dugas JR, Andrews JR. Recent advances in the rehabilitation of anterior cruciate ligament injuries. J Orthop Sports Phys Ther. 2012 Mar;42(3):153-71.
  2. Holt K. Rehabilitation After ACL Reconstruction – Perth Orthopaedic. Perth Orthopaedic and Sports Medicine Centre. 2016:1-6. Available from:
  4. Carmo Almeida TC, Alcantara Sousa LV, Melo Lucena DM, Santos Figueiredo FW, Valenti VE, Silva Paiva L, et al. Evaluation of functional rehabilitation physiotherapy protocol in the postoperative patients with anterior cruciate ligament reconstruction through clinical prognosis: an observational prospective study. BMC Res Notes. 2016 Sep 23;9(1):449.
  5. Mlcheo W, Amy E, Sepulveda F. Anterior Cruciate Ligament Tear. In: Frontera WR, Silver JK, Rizzo TD Jr, editors. Essentials of Physical Medicine And Rehabilitation Musculoskeletal Disorders, Pain, and Rehabilitation. Third Ed. Philadelphia. Elsevier Saunders; 2015.
  6. Kibler WB, Herring SA. General Principles of Rehabilitation. In: Safran MR, McKeag DB, Van Camp SP, editors. Manual of Sports Medicine. Philadelphia. Lippincott-Raven; 1998.
  7. Satpathy GC. Sports Medicine and Exercise. Delhi. Isha Books;2005. Chapter 6, Anterior Cruciate Ligament Prosteses; p. 153-60.
  8. Kim DK, Hwang JH, Park WH. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction. J Phys Ther Sci. 2015 Sep; 27(9): 2693–2696.


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