Knot-tying and suture-passing techniques

Prepare. Make sure all potential equipment and devices are available before the case.

Create accessory portals under direct vision using a spinal needle to assess angle of entry to be able to successfully pass suture through tissue.

An attempt should be made to place the portal in an adequate position to allow for a reasonable amount of swelling. For example, placement of the lateral portal too close to the lateral aspect of the acromion may lead to difficulty performing adequate acromioplasty and bursectomy.

Maximize visualization before starting the reparative procedure. Remove obstructing bursa or soft tissue.

Perform a standardized and reproducible survey of the joint and periarticular structures before beginning the repair. Focusing on only the known pathology may lead to missed diagnoses.

Work quickly on secondary procedures such as acromioplasty to minimize unnecessary soft tissue extravasation.

Obtain adequate hemostasis. Failure to do so may ultimately lead to longer operative times with difficulty visualizing the structures. Irrigation mixed with epinephrine, and pressure control pumps for irrigation control may be helpful. Prevention of elevated blood pressure is useful to maximize visualization of work in the subacromial space. Radiofrequency ablation may be a useful adjunct but use caution to avoid chondrolysis and other potential complications. ^,

Prevent tangling of sutures when multiple anchors are used. We recommend that sutures from each anchor be placed in different portals to prevent entanglement. Other options include keeping the sutures “outside” of a cannula interposed between the cannula and soft tissue or using a small stab incision to serve as a suture repository while other suture limbs are being passed.

Different repairs require different suture passers. Gaining comfort with multiple suture-passing techniques allows for better tissue fixation and a quicker operative procedure.

A clear cannula in the working portal allows visualization and prevents soft tissue from interfering with the knot as it slides to the tissue.

Only one set of sutures should be retrieved into the working portal used for tying the knot.

Use the portal that is best directed over the anchor to allow better suture sliding. Be sure to check that the suture slides easily before attempting to tie a sliding knot.

If the suture does not slide, a nonsliding knot, such as a surgeon’s knot, followed by three reversing half-hitches on alternating posts (RHAPs) is necessary.

Before the knot is tied, a knot pusher may be passed down the suture to untwist the suture.

Advanced arthroscopists may choose to forego the use of a cannula. If this method is chosen, we recommend that a ring forceps be placed around both suture limbs inside the working space and retrieved together to avoid soft tissue interposition.

Select the suture limb that will function as the “post” that allows for best tissue approximation and compression. In a mattress suture configuration, the post can be either limb. In the simple suture configuration, pick the post away from articular cartilage. This suture limb is usually on the tissue side, allowing for maximal compression of the tissue against bone and also directing the knot away from the joint, thus avoiding articular injury from the resultant knot.

Place a clamp on the end of the suture post limb before tying a knot. This prevents the knot pusher from sliding off the post and provides resistance as the knot is tightened.

Visualize the knot as it slides to the tissue to ensure that the tissue is compressed to the desired location.

Maintain tension on the post limb as the knot is seated, to avoid loosening. This is especially important for nonlocking knots.

“Past pointing” is a technique by which the knot pusher is used to tension the knot by switching the tension to the loop limb and pushing past the knot with the post limb of suture (see Fig. 3.7 ). This technique allows the knot to fully seat, which increases the knot security provided by the knot’s internal friction.

“Over-pointing” is a technique in which the opening of the knot pusher is passed over the knot itself while keeping the tension on the post limb.

A sliding knot is secured with at least three RAHPs. Attention must be paid to the tension being placed on the limbs to avoid inadvertent flipping of the knot (e.g., flipping an underhand reversed half-hitch to an overhand half-hitch on the same post). Post may be switched by alternating which limb is being tensioned with each sequential half-hitch, thus avoiding transferring of the knot pusher between limbs. ^,

Be patient. Allow extra time on all arthroscopic cases in the beginning.

Practice your knot-tying skills. The time to practice is before the case when you are not under pressure. When practicing, use bigger string or rope to view the knot configuration. Dry and wet laboratories are extremely helpful and should be used for training when possible.

Management of suture requires careful attention. You must practice and visualize your knot tying. Make it as easy and automatic as tying your shoes.