The short answer?
I’m often approached with this question and clients explain that they sometimes struggle to get a definitive ‘Yes’ or ‘No’ from their Physician. The response they tend to receive is described as a shoulder shrugging “I guess you can go if you want to”.
Several things can be to blame:
Poor past experiences personally or professionally.
A lack of knowledge of what the Physical Therapist can do in the form of treatment or simply from a monitoring standpoint.
The simple belief that the surgery completely fixed all issues and a normal healing process is all the patient needs.
The result is that clients and patients sometimes slip through the cracks of a normal healing process and issues remain long after the initial injury and resulting surgery because the skill set of a Physical Therapist was never considered.
A Physical Therapist has a unique role as a Provider which allows them to spend significantly more time with a client/patient during the provision of treatment and can offer more real-time knowledge and advice than many other providers involved in the same client’s overall care.
Following surgery, common sense would make us immobilize the limb as it heals, which seems perfectly reasonable. But, in fact, the opposite is true (in most cases). Early movement and slow, graded loading of the healing tissues causes an improved healing response. While it may be uncomfortable at times, the intent should never be to overload new, healing tissue but to load it appropriately to improve tissue tolerance and build strength.
For instance, following an ACL replacement, the first 10 weeks (protection phase) after surgery are the most important but tend to be somewhat boring for both the clinician and the patient because of the necessary emphasis placed on protecting the repair. Consider the graft, whether it is a TENDON that belongs to you (autograft) or a donor was kind enough provide you with a hamstring, patellar or achilles TENDON (allograft) to become your new ACL. In either scenario a tendon is not a ligament and a ligament not a tendon.
However, your body will remodel this newly installed tendon over the course of your recovery. This remodeling process alters the loading properties of the donor tendon and slowly converts it into a ligament.
Ligaments slow down and/or prevent shearing forces. Think of rubbing your hands together. The surfaces are sliding back and forth (moving perpendicular to each other), in the case of your knee, the tibia (shin bone) is being prevented from sliding forward relative to the femur (thigh bone).
Whereas tendons are better suited for tensile loading. Like tug of war where there are two evenly matched opponents pulling each other back and forth.
The following list (in no particular order) is just a small number of things a Physical Therapist is considering each and every time you work with them:
Monitoring healing and checking for any sign of infection
Reducing pain, desensitizing the surgical area
Getting the quadriceps (thigh) muscle firing again
Achieving full knee extension (get that knee straight)
Normalizing walking patterns
Scar Mobilization (getting the scar tissue moving)
Improving hip strength/endurance
Restoring total leg strength/endurance
Do not compromise or allow the client to compromise the surgery (Duh - big overarching rule through the entire recovery)
Typically, when there is damage to the knee, the brain does not differentiate between surgery (controlled trauma) and a fall, car accident, etc. (uncontrolled trauma). To the brain, trauma is trauma is trauma. The surgery results in healing tissue and swelling. Your knee can tolerate a finite amount of swelling before the quadriceps muscle begins to become inhibited (turned off, dumb, doesn't fire appropriately, etc). This inhibition results in the hamstrings and calf providing extra support the knee which creates stiffness/tightness and prevents you from fully extending (straightening) the knee. This lack of full range of motion creates more friction and results in more irritation of the joint more which then creates more swelling. If these variables go unaddressed you can get stuck in this cycle of dysfunction.
Insurance rarely allows you to extend your therapy beyond the 12 week mark and while you may feel stronger, more stable and generally better than you did prior to surgery the first 3 months are just the beginning. Recovering from this surgery and returning to sport can range anywhere from a 9-24 month period.
This recovery period may seem longer than anything you've heard or been told and can be highly variable from patient to patient. However, research shows that the absolute minimum length of time between surgery and return to sport is 9 months. There has been some research which suggests that even after 9 months of treatment very few clients can meet return to sport criteria. There is other research which shows that for each month beyond month 9, with continued supervised strengthening and treatment, your risk of re-injury reduces by 51%.
A smart guy (Dr. Travis Jewett; @drjewett07) created/refined the flow from surgery to optimal performance in the image below and in so few words simplified the frustrations of so many healthcare providers who, due to insurance restrictions, are never able to treat beyond getting patients functional (4-12 weeks).
Even in the event that insurance allows return to sport treatment/training, many Physical Therapist's and other healthcare providers are not well versed at prescribing higher level exercises, yellow therabands and the leg press will only get you so far. To reduce the chance of falling into the "gap" and truly address return to sport needs and goals you need to find a clinician who can assist you in advanced strength training and periodization to provide the most well-rounded approach in building/progressing strength, flexibility, endurance and agility.