You’ve Injured Your Knee…..Now What?

You’ve Injured Your Knee.  Now What?
by Steve A. Mora, MD

I am very sorry to hear that you’ve injured your knee.  This is such a common injury in people of all ages.  It seems like active individuals tend to injure themselves more often however knee injuries can even happen with simple squatting or walking downstairs so basically it can happen to anyone.

Knee injuries come in many flavors.  Younger folks tend to have more ligament tears mainly due to the higher energy injury mechanism.  Some of the common knee injury diagnoses I see include: simple ligament sprains, stress injuries to bone or cartilage, meniscus tears, articular cartilage lesions, ligament tears, and fractures.

These are a few situations that require urgent evaluation by a medical doctor:

1)       If you had a pretty significant trauma and you felt a sudden pop or crack or snap, you might have an anterior cruciate ligament (ACL) tear, fracture, medial collateral ligament (MCL) tear, fracture or patella dislocation.  These all need special attention so see your doc asap.

2)       If you twisted your knee and all of a sudden it really doesn’t extend or flex much at all.  You might have a displaced meniscus tear which is locking your knee.  You are going to need an MRI and probably surgery.

3)       If you felt a huge pop in the front of your knee and not it has no extension power you probably ruptured the patella tendon.  This is a very big problem that will require surgery asap.

4)       Your knee keeps giving out, perhaps feels wobbly, or it goes out in a very painful way.  Probably a cruciate ligament tear.

5)       When you apply weight it so painful that there is no way you can walk.

6)       Basically anytime you feel a big pop or crack it’s not good.  See a doc asap.

If your pain is mild to moderate and does not fit the above scenarios you might be okay waiting a bit before seeing your doc.  You might try some over the counter ibuprofen, apply an ACE wrap, ice therapy 20 min on 20 min off, off the shelf brace or sleeve and rest.  Your body is always trying to heal itself so it’s okay to give it a chance.  Rest means rest.


Meniscus Tears and Articular Cartilage Lesions

If you feel sharp pain on the inner side of the knee and the onset was either sudden or maybe after a run, you might have a medial meniscus tear or an articular cartilage lesion.  A cartilage lesion usually takes a little more force to develop therefore pain on the inside of the knee after some sort of strain is probably a medial meniscus tear.   The interesting this about a medial meniscus tear is that a times the knee might actually feel ok and then all of a sudden the pain is back.  There might be swelling or stiffness.

If the symptoms don’t go away on their own after 2-4 weeks come in for a visit.  Make an appointment with an orthopaedic surgeon, you might need some meds, a brace, an injection, physical therapy (PT) and perhaps an MRI. In some cases, not all, surgery will be required.  Surgery for a meniscus tear is done on a elective basis.  That means you can usually take your time choosing the date.

Articular cartilage lesions can present just like a meniscus tear.  They feel and act pretty much the same.  In the orthopaedic literature articular cartilage lesions are also called chondral defects.  The articular cartilage is the surface lining of the knee while the meniscus is the rubbery pad in the space formed by the bones.  These lesions occur in similar fashion as does a meniscus tear.  The younger the patient the more likely the lesion is isolated and discrete.  The older the patient the more likely the lesion is degenerative.  Some articular cartilage lesions occur without a known reason such as  Osteochondritis dissecans (OCD).  Most of the time articular cartilage lesions are associated with an ACL tear.  Interestingly, it is more common to identify an articular cartilage lesion as the time of a meniscus or ligament surgery.



The Conservative Approach (No surgery) or Optimistic Observation

I believe that that body is constantly trying to heal itself.  Therefore it’s okay to give it a chance.  The conservative option is best for those individuals who have little pain and who are still able to perform at an acceptable level.  If you can do what you need to do in life and your comfortable doing it, you don’t need to have surgery.  Non operative treatment can include a steroid injection, PT, anti-inflammatory medication, activity modification and bracing.

Knee Arthroscopic Surgery for Meniscus and Articular Cartilage Lesions

This option should be selected for healthy individuals who have a documented (MRI) meniscus tear or an articular cartilage defect and who have persistent symptoms that are affecting ones function to a significant degree

Arthroscopic surgery is usually done with general anesthesia but I can also do it with local anesthesia and minimal IV sedation. 

For meniscus tear surgery, about 90% of the time the tear is trimmed rather than sutured together.  This procedure is called partial meniscectomy.  Two small incisions are made to introduce the arthroscope and a slender instrument similar to a nail clipper is used to trim the torn pieces.  The procedure is done as an out-patient; that means you go home the same day.  I recommend you rest the first 3 days and limit your activity the next 1-2 weeks.  Most of my patients use a cane on the opposite side after surgery.  I prefer that post op patients  have a course of physical therapy 2 times a week for 6 weeks.  Patients usually go back to sports at 6 weeks.  In rare cases the meniscus tear is sutured back together.  This is called a repair.  A repair is usually not performed because the torn pieces are usually too many and the area torn usually has very poor healing potential.   However in young patients the tear may not be so complex and the tissue bleeds well so it’s possible to repair.  If your meniscus is repaired you will have to protect your knee for the next 3 months.  You will require crutches and maybe a brace for at least 6 weeks. Also after a repair it is not recommended you go all out with sports for 6 months.

Articular Cartilage lesions:  Initially these injuries can be treated non operatively just like a meniscus tear however for cases that do not improve surgery can be performed.  The treatment option depends on many factors however depth of the injury and size are very important. Remember that an articular cartilage lesion is an injury of the lining.  All linings have a thickness.  A full thickness tear means the cartilage injury is through the whole thickness of the cartilage and its showing bone.

Partial thickness articular cartilage lesions (grade II-III ): Treated with debridement or simple chondroplasty.  This means the rough surfaces and edges are shaved and smoothed out.  This procedure is effective in relieving the catching or grinding sensation but there still be some achiness with strenuous activities.

For full thickness articular cartilage lesions (grade IV): These are deep lesions that involve the full thickness of the lining.  Essentially the options here involve resurfacing rather than just buffing the surface.

Microfracture or Abrasion Chondroplasty- This is usually the first line of cartilage resurfacing surgery for Grade IV defects or for those which have failed simple chondroplasty.  A small pick-type tool (awl) is used to make perforations or pick holes in the bone within the center of the lesion. These holes allow marrow blood to seep into and fill the defect.  With time the marrow blood will firm up and become a type of repair cartilage (fibrocartilage).  Sometimes the pick instrument may does not reach certain areas of the knee so a abrader instrument (burr) is used instead.  The concept is the same.  Post-operatively crutches and motion machine (CPM) is used for 6 weeks.  If you don’t protect the knee during the initial 6 weeks healing of the lesion may not occur.   I don’t recommend running for 6-9 months.  If you cannot commit to the post op rehab it’s best not to do a microfracture.

If we find a full thickness defect that is great than 2 cm diameter or one that did not heal with microfracture/abrasion chondroplasty, secondary methods of resurfacing may be considered.  These include:

Osteochondral grafting (OATS) I take small plugs of bone and cartilage from a less critical area of the knee and transfers them to the injury site.  It is like a “hair plug for men” procedure in the knee.  Sometimes it requires a 2-3 inch incision.  After surgery you will need to be on crutches for 6 wks.  The plugs can also be taken from a cadaver knee.  This graft would be called a Fresh Allograft Osteochondral transfer.

Autologous Chondrocyte Implantation (ACI) a.k.a. Genzyme or Carticel:  This is a cartilage cell transfer or implantation procedure.   It requires 2 surgeries.  Part one is to obtain a sample of your knee cartilage by doing a simple arthroscopic surgery.  The cartilage sample is sent to a lab which over time will culture or grow millions of your cartilage cells (chondrocytes).  Part two is the implantation procedure.  Once the sufficient cells are available, the cells are transferred into the full thickness articular cartilage defect. This usually requires an open procedure, or 2-3 inch incision. The success of Carticel ranges from 75% to 90% excellent result.  It is best in certain areas of the knee. Not everyone is a candidate for this surgery.  It is not recommended for patients with arthritis. 

There is a lot of information on line regarding knee injury treatment and cartilage injury treatment.  I recommend you start at  If you are concerned about your knee or need a second opinion see a sportsmedicine trained orthopaedic surgeon for a detailed exam and x-rays. 

I hope this information helped you with your knee injury.  Good luck.


Steve A. Mora, M.D.

Orange County Board Certified Orthopaedic Surgeon Fellowship Trained in Sports Medicine

Shoulder, Knee, Elbow, and Sports Medicine Specialist

Special Interest in MMA and Soccer Injuries

You can request an appointment with me by calling 714 639-3750 or going to my web page