MPFL REcon
Thank NYYANKEES - I was in that ballpark but the doc asked me to check it out with colleagues. The problem is I cannot tell if it is extra-articular or intra-articular or both - not getting much help from the docs and I cannot explain why.
POSTOPERATIVE DIAGNOSIS: Right knee recurrent patella instability.
PROCEDURE:
1. Right knee examination under anesthesia.
2. Right knee arthroscopy.
4. Right knee open medial patellofemoral ligament reconstruction with
allograft semitendinosis.
WHAT WAS DONE: The patient was brought into the preoperative area.
Site and side were identified. She was then brought in the operating
room and placed supine on the operating room table. Bony prominences
were padded appropriately. LMA anesthesia induced. Examination of
the left knee under anesthesia revealed 1 cm of patella glide with the
knee in full extension, 1 cm of patella glide with the knee in 30
degrees of flexion. When compared with the operative extremity, the
right knee had 1.5 cm of patella glide laterally in full extension and
at 30 degrees of flexion was able to be fully dislocated. The right
lower extremity was then prepped and draped in a sterile fashion.
Bony landmarks of the anterior aspect of the knee were marked with a
marking pen including the patella, anteromedial and anterolateral
portal sites. An 11-blade scalpel was used to incise the skin of the
area of the anterolateral portal and a diagnostic arthroscopy was
begun. There was no evidence of chondromalacia of the undersurface of
patella or femoral trochlea. The patella was easily able to be
dislocated over the lateral aspect of the femoral trochlea.
Diagnostic arthroscopy continued to medial compartment. Medial
femoral condyle, medial tibial plateau and medial meniscus showed no
evidence of chondromalacia or tearing. Intracondylar notch and ACL
was in good condition. The lateral gutter was entered. There was no
evidence of chondromalacia of the lateral femoral condyle or lateral
tibial plateau, no evidence of lateral meniscal tear. Additional
pictures were taken showing that the patella easily subluxated out of
the femoral trochlear sulcus. Once the diagnostic arthroscopy was
complete, tourniquet was inflated. A longitudinal incision was made
over the medial 1/3 of the patella. Blunt dissection was carried down
to the extensor retinaculum. The 3 layers of the knee capsule were
then identified. The interval between layers 2 and 3 was identified.
The medial border of the patella was cleared of all soft tissue and
decorticated using a rongeur as well as a curette. Once this layer
between 2 and 3 was identified, a blunt mosquito clamp was used to
create a path toward the eventual site of the femoral tunnel.
Fluoroscopic images were obtained in the true lateral plane to look
for the anatomic attachment site of the MPFL on the femur. Once this
was localized via fluoroscopy, incision was made to the skin and blunt
dissection was carried down through layer 1 of the medial knee
capsule. A short Beath pin was placed in the area of the anatomic
attachment of the MPFL and advanced through the femur and out the
lateral aspect of the femur. Its position was checked via fluoroscopy
and was felt to be adequate in all planes. A stitch was passed from
the patella incision to the posteromedial incision, and a length
change test was performed. The position of the MPFL on the femur was
felt to be adequate. A #7 reamer was placed over the Beath pin and
advanced to a depth of 25. Once the reaming was complete, the graft
was being prepared on the back table. This consisted of doubled over
semitendinosis tendon with a proximal 20 mm of tendon whipstitch
together and each of the 2 ends then subsequently whipstitched and
separated. The doubled over end was passed into the femoral tunnel
using the Beath pin, and once it was well secured, a 7-0 bioabsorbable
screw was placed over a nitinol wire. Care was taken to try to place
the screw posterior or posteroinferior to the graft. Once the graft
was secured, it was tested with longitudinal traction and felt to be
stable within the femoral tunnel. A Kelly clamp was passed from the
anterior incision to the posteromedial incision, and the graft was
passed in a standard fashion. Two double-loaded bio suture tacks were
placed into the medial border of the patella. One limb of each of the
2 suture tacks was placed through the graft. The leg was brought
through range of motion; it was felt to be stable. There was no slack
in the graft, but no tension. It was able to be ranged from full
extension to approximately 120 degrees without excessive tension in
the graft. There was approximately 1 cm worth of lateral translation
with the knee in about 30 degrees of knee flexion. This was similar
to the contralateral side. The graft was secured additionally with
the second set of stitches within the bio suture tacks. Once again,
range of motion was performed. The incised extensor mechanism was
then reached over the anterior aspect of the knee and medial
patellofemoral ligament repair. Copious irrigation was then
performed. Subcutaneous tissue was closed with 2-0 Vicryl in
interrupted fashion, skin edges approximated with 3-0 Prolene in a
subcuticular manner. Half inch Steri-Strips were cut in half and used
to approximate skin edges as well. Marcaine 0.25% with epinephrine
was injected around the incision. A sterile dressing was applied.