- Amputate femur approximately 8 inches above joint line
- Amputate tibia approx. 6 inches below joint line (or may keep lower leg)
- Secure specimen in long holding clamp
- Inside out meniscal repair guides
- Meniscal repair needles
- Two #18 gauge spinal needles
- #0 PDS suture
- Arthrex wire loop or Linvatec suture shuttle
- Self-retaining retractor
- Fast Fix meniscal repair instrumentation and device
- Army Navy retractor
Standard inferomedial and inferolateral portals.
1) Dissect, through small vertical incisions, the posteromedial and posterolateral corners. Then expose on both sides the interval between the capsule and the gastrocnemius.
Make a 3 cm vertical incision superior to the posteromedial joint line. Divide the fascia along the anterior margin of the sartorius after identifying its muscle belly. Blunt dissection is used to develop the extracapsular plane between the medial head of the gastrocnemius and the semimembraneous tendon at its tibial insertion. Identify the joint line sulcus and then place a retractor there to protect the saphenous vein and nerve during needle retrieval.
Make a 3 cm vertical incision superior to the posterolateral joint line. Expose between the iliotibial band and the biceps femoris tendon and identify the tendinous origin of the lateral head of the gastrocnemious. Dissect between the lateral head of the gastrocnemious and the joint capsule. Identify the joint sulcus and then place a retractor there to protect the popliteal artery and the peroneal nerve during needle retreival.
2)Practice inside-out meniscal repair first
The guides for inside-out meniscal repair are: right posterior, right middle, right anterior, left posterior, left middle, and left anterior. They are to be used from the contralateral portal and should correspond to the zone of the meniscus and the desired direction of the needle.
The needles are "double armed" so each needle can pierce a point on the meniscus about 5 mm apart at the appropiate fixation point.
- Practice passing needles through the middle part of both the lateral and medial meniscus.
Below is an arthroscopic and exterior view of a meniscal repair guide used for repairing the middle part of a left lateral meniscus (the guide is inserted from the contralateral portal and curved to the right).
- The needle should be visualized as it exits the capsule and then grabbed with a hemostat. Appropiate retraction with a self retraining retractor or an army-navy retractor is necessary to adequately visualize the exiting needles. This visualization is particularly important on the lateral side in order to avoid damage to the peroneal nerve. In this exercise, you may want to completely expose the peroneal nerve prior to passing needles on the lateral side of the knee.
- After piercing the first needle through the meniscus, gently move the guide to a point about 5mm away from the first fixation point and then again pierce the needle through the meniscus.
- After retrieving both needles, cut the needles from the sutures and then tie the two sutures over the capsule.
- Repeat this procedure at a location on the posterior horn of the meniscus.
3) Practice outside-in meniscal repair
This technique is particularly useful for a reduction stitch in repair of a bucket handle tear of the meniscus. This technique cannot be used for repairs of posterior horn tears of either meniscus. It is the preferred technique for tears of the anterior horn of the menisci.
- Place a 5.5 mm blue cannula in the ipsilateral portal
- Take a #18 gauge spinal needle and pierce the capsule of the desired area of the meniscus repair. Once the needle is through the capsule, pierce the meniscus. Pass a # 0 PDS across the needle and then retrieve it with a grasper through the cannula.
- Make a small vertical incision at the area of needle and then take a hemostat and spread the soft tissue down to the capsule.
- Take another needle and either pierce the capsule (for a vertical suture) or the meniscus (for a horizontal suture). For a vertical suture, the capsule is pierced just superior to the area where the first needle had been passed through the meniscus. For a horizontal suture, the meniscus is pierced at a location about 5mm from the first suture.
Two spinal needles traversing meniscus for a horizontal meniscal repair.
- Retrieve the second suture through the cannula
- Tie a "mulberry knot" with the two sutures exiting the cannula
- Pull the two strand of sutures from the outside until the knot coapts against the meniscus
- Now tie the two remaining strands of suture over the capsule. Be careful no to overtighten since the sutures can break
- There is a variation to this technique where after passing the second needle a wire suture shuttle device is passed instead of a second suture. The wire is then grasped and brought out of the cannula. There is an opening at the middle of the wire loop and through this opening the suture from the first needle is passed. After passing the suture through the wire loop, the wire is pulled from the outside. This act will pull the suture through the capsule.
- Once the suture has been pulled through the capsule, the two strands of suture are tied over the capsule. Again, be careful not to apply too much tension.
4) Practice fast fix meniscal repair
The FasT-Fix device (Smith & Nephew, Andover,MA.) is an all inside repair technique with superior fixation strength when compared to other all inside meniscal repair devices. The device consists of two polymer T bars (implant) joined by a suture sling containing a preloaded sliding, self-locking knot. Consult the company's video or brochure regarding the full description of the implementation of this device (copy of the surgical technique is available at the arthroscopy lab).
A brief summary of the steps to this procedure demostrating a horizontal mattress suture:
- Approach the tear from the contralateral portal. Hold the delivery needle "like a dart" in order to reduce the chance of bending the needle on insertion and to improve tactile feedback.
- Once in position, advance the first anchor (implant) through the entire meniscus tissue.
- Direct the second anchor at a spot about 5mm from the first anchor. Before advancing the suture, make sure it is fully advanced to the deployment position at the tip of the delivery needle.
- Thread the sliding knot suture through the knot pusher/cutter. Initially, place gentle perpendicular traction on the suture. After preliminary tightening, the pusher/cutter is used to provide gentle countertraction as the suture is pulled. The knot should be tightened in gentle, slow increments. After adequate cinching of the knot, cut the suture with the pusher/cutter.
- Below is a photo of the junction between the posterior capsule and the meniscus. Note that the implant does not traverse the posterior capsule but is captured on the meniscus rim.
- Do a thorough dissection of the menisci of the knee
- Pay special attention to the meniscal attachments, and the relationship of neurovascular structures (popliteal vessels, peroneal nerve, and saphenous nerve) to the menisci
- Note the relationship of the capsule to the menisci
- Identify the differences in shape, position and attachments between medial and lateral meniscus.