Extracapsular Suture Techniques
There are numerous methods of CrCL “repair” which attempt to provide stability to the stifle joint by using suture prostheses made of varying sizes and types of material (nylon, fishing line, polypropylene, FiberWire®, Ethibond™, etc.), with varying numbers of sutures, locations and methods of fixation. Some materials and techniques, naturally, are likely better than others. And in the case of commonly used fishing line, well... it's probably best-suited for fishing!
One of the most common approaches, also known as a Lateral Extracapsular Suture Stabilization (LESS) involves placement of a single suture loop external to the joint from over/around the lateral femoral fabella and through a bone tunnel drilled in the tibial crest to mimic the orientation of the CrCL. When tensioned appropriately, these suture prostheses control, to some degree, abnormal joint motion - for a time. A common misnomer is to refer to this approach as an “artificial ligament” - it is not. The suture(s) provide only temporary stabilization and will loosen, break or fail over time. These techniques rely upon degenerative, joint capsule thickening (scar tissue) to provide long term joint support. Peak, though not necessarily complete, recovery following LESS is typically seen at 18-20 weeks postoperative.
Common complications and technique error of LESS is an inappropriately positioned tibial tunnel and over-tightening of the suture implant(s). This leads to pain, decreased joint range of motion, excessive joint compression, cartilage damage, risk of meniscal injury and early implant failure.
The Corkscrew and FASTak suture anchors were designed to provide the highest strength possible in a variety of indications - including the cranial cruciate ligament insufficiency in the dog.
These anchors make operations simple, safe and, importantly, reproducible with easy to use depth and alignment aids. Combined with the high strength characteristics and increased abrasion-resistance of FiberWire, suture breakage is virtually eliminated during tensioning and knot tying.
The FASTak and Corkscrew implants are suitable for dogs ranging from 20-50 pounds, respectively.
In clinical application at ACOSM, at left is the postoperative radiographic appearance of the FASTak anchor in a Cocker Spaniel dog for management of cranial cruciate ligament rupture/insufficiency.
The TightRope® CCL technique was introduced in 2005-2006 and provides an option for extracapsular stabilization of the cranial cruciate ligament-deficient stifle. TightRope® utilizes very strong and stiff bands of synthetic material called FiberTape® (as opposed to previously used, conventional suture materials) passed through small bone tunnels of the tibia and femur.
The objective of TightRope® CCL is to counteract cranial tibial thrust, cranial drawer and internal tibial rotational instability while providing more optimal joint range of motion. The technique avoids the trauma of cutting through the bone of the tibia like a TPLO, TTA or TTO.
The TightRope® CCL technique is based on the lateral fabello-tibial suture (LESS) principle. The purported advantages of TightRope (TR) over the LESS include bone fixation at both tibial and femoral attachments, more accurate isometric placement and the superior strength, stiffness and creep characteristics of the implant.
Multicenter data suggests TightRope® CCL can be safely performed in medium, large and giant-breed dogs with variable outcomes and nearly 10 percent complications requiring additional treatment.