In our previous blog post we discussed the pathology of ACL tears and briefly touched on the management of ACL injuries. This blog post will highlight and go over the early stages of rehabilitation following an ACL reconstruction (i.e. post surgery).
Pre-surgery Rehabilitation
Although most of the rehabilitation of injuries are done post-surgery, there are great benefits to starting early, even before you have even had the ACL reconstruction. To allow for optimal recovery post-surgery, the aim is to achieve full range of motion equal to the opposite knee, reduce joint swelling, gain a good level of muscular strength and neuromuscular control, and lastly, exhibit a positive state of mind leading up to the surgery. In return, this can help reduce recovery time and help you return to physical activities sooner.
Post-surgery recovery
Range of Motion and Flexibility
One of the most important components of rehab is regaining full range of motion at the knee as soon as possible. This is not only safe for the graft and joint stability, but can help with knee pain and and compensations to your walking pattern. Stretching and re-training the quadriceps (thigh muscles) are typically used early on to promote range of motion.
Early Mobilisation
Following an ACL reconstruction, early mobilisation (walking) has been shown to increase knee range of motion, improve pain, and maintain the condition of the soft tissue structures such as muscles and tendons. This can also assist with re-training alterations to your walking pattern.
Strength Training
Rebuilding muscle mass and improving strength of the muscles around the knee is vital for a smooth recovery. Strengthening of the quadriceps provides greater support and stability to the knee joint, and can assist with improving coordination of the joint and muscles.
Traditionally, it was recommended to avoid open chain exercises (where the foot is free and not fixed to a surface) for at least six months after surgery, due to the movement of the tibia (shin bone) forward, creating strain on the new graft. However, it is now believed to be safe and a great way of targeting the quadricep muscles, when used in addition to closed chain exercises (where the foot is fixed onto the floor or machine). Early on, closed chain exercises (such as squats) on their own are still preferred, until adequate improvements have been made.
Neuromuscular Reeducation
As mentioned in our previous post, the ACL tendon not only provides structural stability, but it is also able to sense movements at the knee and further coordinate the muscles and structures to provide further stability at the joint based on the activity. To target this, balance exercises or perturbation training (where you have to resist an external force) is often used. Improvements can also lead to greater strength gains in the quadriceps and hamstring, improved knee stability and movement coordination.
The recovery timeline
0 - 2 weeks
During this stage, along with reducing pain and swelling, it is important to restore range of motion especially knee extension. There is also a big focus on general flexibility and quadriceps activation. If pain and weight-bearing status allows, balance exercises can be incorporated. Lastly, try to maintain a normal walking patter, even when using crutches.
Example exercises:
1. Heel Slides - for knee range of motion
2. Sit to Stand - Quadriceps and lower body strength
3. Single Leg Balance - balance and neuromuscular training
3 - 6 weeks
At this stage, knee flexion and extension should be nearing full range of motion, allowing for a normal walking pattern. Continue to maintain flexibility and progressively strength the lower body muscles, especially the quadriceps. Balance and neuromuscular training can be increased in difficulty. Aerobic fitness can also be incorporated on the bike or elliptical trainers.
Example exercises:
1. Prone Assisted Knee Flexion - knee range of motion and quadriceps flexibility
2. Wall Squats 12" from wall (45-60 deg) - quadriceps strength
3. Single Leg Balance on foam - balance and neuromuscular training
Summary
This blog post offers a simple overview of the key aims of rehabilitation during the early phases of an ACL reconstruction. Starting rehabilitation early to maintain as much range of motion and strength as possible prior to surgery, and immediately following, can lead to better outcomes and potentially a faster recovery. In the following parts to this series, we will look further into the later stages of rehab, and return to physical activity and sport.
References
Monk AP, Davies LJ, Hopewell S, Harris K, Beard DJ, Price AJ. Surgical versus conservative interventions for treating anterior cruciate ligament injuries. Cochrane Database of Systematic Reviews 2016, Issue 4. Art. No.: CD011166. DOI: 10.1002/14651858.CD011166.pub2.
Physiotherapy ACL Protocol
Fowler Kennedy Sport Medicine Clinic. London, CAN, 2015
Pictures obtained from Physitrack