Extension - This is the ability to keep the leg straight which is considered to be 0 degrees extension. Some OS/PT may desire to get somewhat more than 0 degrees and to actually get a few degrees hyperextension to match whatever is the hyperextension on the good leg. In my case, my OS & PT did not emphasize getting more than 0 degrees extension. It's my opinion that the need to get anything past 0 degrees extension is open for debate especially if the person has no problem with his walking gait or jogging ability.
All OS probably check to see if a patient has full mobilty (flex and extension) as one of the last actions taken before leaving the OR (operating room). The problem is that once the patient is in the recovery room, he is usually faced with a vegetable in place of a leg. Each OS may or may not give guidance as to what to do, if anything, before the first PT (Physical Therapy) visit. That visit may be at 2 days post-op or even as late as 3 weeks post-op, depending on the OS protocol.
As a patient is recovering, the leg somewhat stiffens from non-use and also from time spent in the Immobilizer brace. Also, since the there are basically no muscles and possibly no direction from the OS, the patient may find that all of a sudden the 0 degree extension is now more like 10 degrees extension. It is important to work to keep that 0 degree extenson from day one out of the hospital because some people (a small percentage) may find it a bear to recover the extension lost during the early couch potato days of recovery. Extension is best to regain in the first 4 weeks or so. Otherwise, scar tissue may be holding it from being recovered and the OS would have to be consulted as to what to do next.
Flex - Full Flex is usually considered to be a minimum of 135 degrees to a maximum of when you can touch your heel to your butt. (This is generally around 150 degrees flex.)
The timetable for most patients to recover full flex is generally from around 5 -12 weeks post-op. This can vary. Some may take longer to get full flex and there may be some superstars that recover it before 5 weeks post-op.
Muscle Strength - There is really no timetable on muscle strength. You can get it sooner or later but eventually it will come if you are persistent at doing your exercises on a consistent basis. It is, however, important to make progress on muscle strength since the leg is initially a vegetable and you would be susceptible to incidents of the leg giving way since the muscles are not there to help support the leg. Many OS start releasing patients for all activities when they are 85% to 100% of full muscle strength and the patient is pas whatever the OS considers as his minimum time for releasing patients for activities. Some OS will give a specific release for certain activities at some time earlier than the full release. For example, I was given a release for biking and swimming at 3 mos post-op, when I was at approximately 50% full muscle strength. I was released for all activiies at 6 mos post-op at approximately 85% full muscle strength and I achieved full muscle strength at 7 1/2 mos post-op.
Of those that get released earlier than the above example, ahigher percentage come form the younger individuals. However, depending on recovery progress and any complications/setbacks along the way, release for all actitivities can be delayed as well.
Physical Therapy / Physical Therapist (PT)
Most ACL reconstruction patients will begin PT at 1-2 weeks post-op. Depending on insurance coverage, you may be limited to the amount of sessions or months of PT. When PT ends, the patient oftentimes will have to continue with his home program of exercises and supplement it with more challenging exercises at the recommendation of the PT. a membership at a fitness ctr is excellent for continuing the type of exercises that will help recover full muscle strength.
So, how much PT ? PT can vary from 1 - 3 months of sessions 3 times a week. This varies a lot depending on health insurance, OS protocol and othe factors. PT initially assists the individual with regaining flex, extension and starting some basic muscle strength exercises. Electro-stim is sometimes used to promote healing and stimulate muscle activity. Electro-stim does not hurt but does produce a tingly feeling where the PT ooks up the stim pads. The PT usually asks you to what level of tingliness is still comfortable and then it cycles on and off at that level for about 10 minutes.
After the patient makes progress on flex and extension and usually the basic straight leg lift muscle strengthening exercises, the PT thenstarts the patient onto the lifecycle. The lifecycle requires approximately 125 degrees of flex , so don't expect to go on the lifecycle the first day or at least don't expect to be able to pedal circles unless you have already obtained adequate flex.
The lifecycle will then be a regular warmup exercise with some resistance settings as a prelude to moving on to more challenging exercises.
PT can be boring to some, painful to others and in my case, I found it challenging and fun.
A good PT will move you along as you make progress and according to a timetable they may have regarding ACL reconstruction patients and even perhaps the specific reconstruction method. A good PT will spend time with you to ensure you can do the next level of exercise. A good PT will communicate your progress/non-progress regularly to your OS. A good PT will keep a diary of your progress. a good PT should be able to keep the exercises challenging and instrumental in progressing you to functioning fully as before your injury.