Surgery – What Works and What Doesn’t
Surgical treatment of the patella has three potential areas that can be treated, the lateral side, the medial side, and the tibial tubercle. Adequate treatment of each area is necessary to provide the best improvement and resolution of the problem. Less than optimal surgical technique in any of these three areas will produce an unsatisfactory result.
Lateral release as isolated procedure rarely resolves the problem because:
- It is only part of the problem
- Technically, the lateral release may be poorly done
- It is all the surgeon knows how to do
“I had lateral release surgery on my left knee in 2005….. The surgery did help
me for about 6 months then unfortunately I started having problems
again…. The lateral release has helped some, and some it hasn't….."
"I have finally accepted the fact that my knees will not ever be the same as they
were before. You have to set your state of mind at what you can do... "
"I had a lateral release 3 months ago and now my patella is more unstable
than before surgery..."
These are typical patient comments as their history is taken. The lateral release has not addressed all of the pathology. The patients are discouraged and never expect to get better. Activities have been modified. They remain quite painful. Here are the reasons why this occurs:
- In either pressure or instability, a lateral release usually improves the problem only for a short time if at all. The underlying problem is still present and must be treated if permanent improvement is desired. Malalignment and pressure may temporarily improve but then the symptoms will reoccur. If instability is present, lateral release usually worsens the instability. If the previous lateral release has failed, the treatment is not another lateral release. Yet this often occurs.
- To have a chance to be effective at all, lateral release must be correctly done. The tightness is located at the inferior lateral corner of the patella. This is the area that must be released to allow the patella to center in the femoral trochlea. In revision surgery, it is common to see the release done well above this area and not done where the patella was tight. Releasing the lateral retinaculum above the tight area, will significantly worsen instability by lengthening the lateral structures. This destabilizes the patella. It is also possible to develop significant arthritis in the medial patella and femoral trochlea in a previously normal knee. This pattern of arthritis is not typical and only occurs after a poorly done lateral release.
- The surgeon does not have any idea what else to do or why the surgery has not resolved the symptoms. He tells you that you have to live with it, there is no solution. See: The Problem
Lateral release is always necessary to allow the patella to center without pressure in the femoral trochlea. The inferior lateral corner of the patella will restrict patellar position change if not released. This occasionally can be accomplished by arthroscopy in appropriate cases.
If part of an open realignment surgery, the lateral release should be repaired after the tibial tubercle has been repositioned and the patella is centered. The soft tissue defect created by the lateral release can be closed with local tissues from the iliotibial band. This will prevent lateral side instability secondary to the lateral release. Stability after surgery is far better if the lateral release is repaired than if it is not.
View from the lateral portal. The patella is above and the femur below. The knee is extended. The patella tilts to the lateral side, a normal relationship. On the right, the knee is flexed to 90 degrees. The patella should contact the femur completely but is too tight laterally and cannot fully center in the femoral trochlea.
View from the medial side portal. The lateral retinaculum is between the patella and femur. It is tight and pulls the patella down. On the right, a hooked knife is used to open the lower part of the lateral retinaculum. This is the lateral release and is being done in a safe area of the lateral retinaculum.
View from lateral after the release. Notice that the patella now is sitting parallel to the femoral trochlea surface. Also notice that with the knee flexed to 90 degrees, the patella now centers fully in the femoral trochlea. However, the release has loosened the patella and made it more unstable. This patient did not have a successful outcome from this procedure and required an open patellar realignment to relieve pain and stabilize the patella.
This is discussed on the page called Lateral Stability. Click on the link to review it.
Medial Side Soft Tissue Repair or MPFL Repair
Medial soft tissue repair will work if patellar position and alignment is correct. Medial side soft tissue repair will fail if alignment and lateral patellar position or stability are not corrected.
An early surgery I did was open lateral release and medial repair. Later, we were able to accomplish the same procedure by arthroscopic technique. Both open and arthroscopic procedures failed and the technique was abandoned. At the time I did not understand these failures but now the reasons for failure are clear. Unfortunately, there has been a new interest in arthroscopic medial repair with lateral release, recently reported in the Journal of Arthroscopy and Related Surgery (April 2007).
Currently, there is great interest in using a tendon to substitute for the Medial Patello-Femoral Ligament (MPFL). This surgery is intended to prevent patellar dislocations. Those advocating this procedure do not address the lateral side or tibial tubercle. The procedure is intended only for patellar dislocation and not pressure or other instability problems. The procedure is technically demanding and there is limited followup of the cases at this time. Overcorrection of medial side stability is clearly possible with this technique.
Tibial Tubercle Transfer (TTT)
Tibial tubercle transfer must be done with good technique. If the underlying concepts of the surgery are correct and the surgery is carried out well, excellent improvement should be expected.
Tibial tubercle transfer will fail if the new position does not decrease pressure, creates extensive scar tissue, or is overcorrected.
Pressure is increased if the tibial tubercle is moved even a little posterior on the tibia or if the patellar tendon becomes scarred to the underlying tibia. Pressure is released by moving the tubercle anterior. Simple changes in the alignment of the saw blade used to undercut the tibial tubercle, will allow the tubercle to move more anterior.
Procedures that move the tibial tubercle only medial or only anterior usually provide incomplete pain relief. The Elmslie-Trillat procedure is probably the most common TTT done. It moves the tibial tubercle only medial. Without moving anterior, pressure is often increased. In addition, scar formation, adhering the patellar tendon to the underlying tibia restricts motion and increases pressure. If a small incision is used, overcorrection often occurs and can produce secondary medial side patellar or femoral trochlea arthritic change.
The Macquet procedure moves only anterior and not medial. This procedure is also disfiguring to the tibia and often produces skin healing problems. This technique produces overcorrection of the tibial tubercle in the wrong direction.
The procedure developed by Dr. John Fulkerson moves the tibial tubercle both anterior and medial and is much better. However the recommended correction is mostly anterior and not medial. Desired correction is at least 10 mm anterior which I believe is somewhat excessive. In addition, the technique does not allow the tibial tubercle to move upwards or downwards to allow correction of Patella Alta or Patella Baja if necessary.
I have combined the concepts of Elmslie-Trillat and Fulkerson and modified their techniques to produce a Tibial Tubercle Transfer that provides correction with less trauma to the tibia. I have used this technique for most of the last twenty years.
Small corrections are better than large ones. The tubercle needs to move medial just enough to straighten the patellar tendon with the knee in flexion. This is done only after the patella has been centered in the femoral trochlea.
The tibial tubercle is completely freed from its bed in the tibia. Anterior position is created by an oblique undercutting the tibial tubercle to allow a combination of medial and anterior translation. The tibial tubercle can also move superior or inferior to correct Patella Alta or Patella Baja as needed because the tubercle is completely freed. Moving the tubercle anterior does not cause the patellar tendon to scar to the tibia. This technique is reproducible and dependable. Once again small corrections are best.
The alignment of the patellar tendon and tibial tubercle after lateral release and centering the patella. Notice the angulation between the patellar tendon and the tibial tubercle.
The tibial tubercle has been undercut and freed from the tibia. The tubercle is pivoted slightly from lateral to medial to match the alignment of the patellar tendon. The angulation has been corrected. The tibial tubercle has been fixed with two screws. This change straightens the patellar tendon mechanism, reduces the lateral pull, and decreases pressure on the patella. The defect on the lateral side of the tibial tubercle will be filled with artificial bone graft (DBX).
Back to top