Knee menisectomy and changes on MRI

The knee meniscus is a fibrocartilage structure that serves as shock absorbers between the thigh bone( femur) and shin bone(tibia).  Injuries to the meniscus can cause knee pain and often are treated with surgery.  Non surgical treatment options of knee meniscus injuries at the Centeno-Schultz Clinic  include Regenexx SD, Regenexx AD, Regenexx SCP and Regenexx PL. 

Knee meniscectomy is an arthroscopic procedure in which a portion of the injured meniscus is cut out.  It is similar to a nip and tuck as performed by a plastic surgeon. There are many studies that question the efficacy regarding this very common procedure.   Other studies have demonstrated that knee meniscectomy  surgery accelerates the degenerative changes in the knee.

How?

The meniscus is changed in size after a meniscectomy.  That means that there is more force on a smaller surface area.  The force arises from daily activities such as walking and running.  This increased force in combination with changes in architecture following the surgery led to degeneration.  Often times the mensicus is also displaced from the joint space.  In the end you have a shock abosber that is smaller in size, prone to weakness and degeneration and partially pushed out of the joint space.  The result is a nonfunctional shock absorber which exposes the cartilage surfaces to increased force.  Over time the increased force leads to bone swelling (edema) which has as patchy white appearance on T2 MRI images.

MRI changes following knee meniscectomy are illustrated below.  The image on the left is a normal knee MRI.  Normal meniscus are triangular in shape and black in color.  They are outlined in yellow circles.  The MRI on the right is after meniscectomy and significant for a change in the size and shape of the mensicus which is identified by blue circle.  A smaller mensicus in this case failed to cushion the thin bone from the shin bone resulting in bone swelling.

Knee Meniscus: Understanding Your Knee MRI

The Centeno-Schultz Clinic offers a large number of non surgical therapies for the knee.  IMS treats dysfunctional muscles. Prolotherapy is used to strengthen loose or sprained ligaments.  Regenexx SD, Regenexx AD and Regenexx SCP can be used to treat damage in meniscus and cartilage.

Understanding your knee MRI is helpful for many patients.  The key structures are identified below.  The image on the left is a frontal view whereas the image on the right is a side view of the left knee.  The principal bones are identified in red:  femur, tibia and fibula.  The meniscus is the dark triangle outlined with dashed circles.  On the left, the yellow circle identifies the medial meniscus whereas the blue circle identifies the lateral meniscus.  The meniscus has an anterior horn and posterior horn which are identified on the image on the right. 

Knee meniscus tears: non-surgical treatment options

The knee has two fibrocartilage strips between the femur(thigh bone) and tibia (shin bone) that are termed meniscus.  They function to disperse the forces generated by activity and reduce friction.

Tears to the meniscus can occur from normal everyday activity, traumatic injuries  and degenerative changes.  Tears can lead to pain and or swelling of the knee. Locking of the knee with inability to fully straighten the leg can also occur.  Diagnosis can be  made by both ultrasound and MRI.  Conservative therapy typically involves rest and physical therapy. Surgical therapy involves resection of the torn area referred to as meniscectomy.  This has significant implications and can actually accelerate the degenerative process.

Stem cell therapy is now a viable option.  The Regenexx procedure allows patients the opportunity to use their own stem cells thereby avoiding the risks of surgery and anesthesia in addition to the extensive post surgical rehabilitation.

DS is a patient who successfully underwent the Regenexx procedure for her arthritic hip pain.  As a result of her mesenchymal stem cell therapy she had significant reduction in hip pain which enabled her to  increase her activity  level. DS has returned to her regular yoga practice.  Unfortunately, during a recent practice she heard a loud pop with abrupt onset of knee pain.  Her MRI is significant for a tear of medial meniscus and laxity of the medial collateral ligament as evidenced by bowing out of the ligament. These findings are illustrated below.  She has declined surgery and is scheduled to return to  Centeno-Schultz Clinic for re-evaluation and probable Regenexx SD procedure along with platelet derived growth factors therapy.

Pictures Dont Tell the Whole Story

Unfortunately there is large emphasis placed on MRI’s in the diagnosis and treatment of pain.

Radiographic studies are diagnostic tools which can assist in identifying a given patient’s pain when utilized in conjunction with a complete history and physical examination.  When viewed alone, MRI’s do not tell the whole story.

Consider the following:

Englund et al, in the New England Journal of Medicine, reported that 60% of patients with knee meniscus tears on MRI had no pain symptoms.

Matsumoto et al examined 497 patients WITHOUT pain and found the prevalence of degenerative disc disease to increase with age:  varied from 15% in patients who were in there 20’s to 86% in patients older than 60 years of age.

Jensen et al., conducted MRI’s of the lumbar spin in 98 patients WITHOUT back pain.  52% of the asymptomatic patients had a disc bulge.  MRI’s of the lumbar spine in patients WITHOUT back pain were normal in only 36%.

Diagnostic radiographic studies alone can not determine the source of a patient’s pain.  At the Centeno-Schultz Clinic we are committed to finding the source of a given patients pain by completing a thorough physical examination, history and review of radiographic studies.  Anything less is simply incomplete.

Understanding Your MRI: Knee Meniscus

The meniscus is tough fibrocartilage between the thigh bone(femur) and shin( tibia).  There are two meniscus per knee: one on the inside (medial) and one on the outside(lateral).

The meniscus functions as a shock absorber and therefore is critical.

The meniscus is C-shaped.

In viewing an MRI it is important to understand the view:  frontal/side/ from the top or from the bottom.

When viewing the knee from the side, the meniscus are two dark triangles between the femur and tibia(outlined in red).

The meniscus is easily viewed from the front as demonstrated below.

There are non-operative options to repair meniscus injuries which include the use of the stem cell therapy.  The Regenexx procedure allow patients the opportunity to use their own mesenchymal stem cells to repair damaged knee tissue.