Dr. Peter Sebestyen; Veterinary Surgical Specialists

May 20th, 2009          

The desire to develop a new treatment method for the same problem strongly suggests that the available techniques are less than perfect.This is certainly true for cranial cruciate ligament tear repair. The choice of surgical treatment for canine cruciate ligament tear is undoubtedly the most debated topic in small animal orthopedics. One of the current controversies regarding TPLO vs. TTA was recently touched on in our monthly newsletter. In this issue, we will continue discussing the debate by introducing yet another procedure, the Tightrope CCL repair.

Tightrope CCL Repair

Dr. Jim Cook at University of Missouri developed the tightrope repair.  The technique is a modification of a human orthopedic procedure used to stabilize the ankle joint.  A bone-to-bone application of a special orthopedic material (Tightrope Tape) manufactured by Arthrex resulted in an improved version of the lateral suture stabilization technique.

There are several specific differences where the Tightrope procedure is thought to be superior to the conventional lateral sutures technique.

Pros:

- Tightrope tape has mechanical characteristics multiple times higher than the strongest nylon line.

- Procedure is performed through small stab incisions and is less invasive. 

- Tightrope tape is placed through bone tunnels providing bone-to-bone fixation; thought to be more stable in time in contrast to perifabellar anchoring.

- Tape is secured with toggle plate eliminating the need for a suture loop around the tibial tuberosity lessening the negative effect on range of motion.

- Position of the tibial bone tunnel is thought to provide a more accurate isometric placement of the tape further improving the range of motion.

Cons:

-Disadvantages are similar to any other extra-articular lateral imbrication techniques. 

- Tightrope tape is thought to deteriorate in time causing the repair to be a dependant fibrous tissue development as a more permanent form of fixation.   

- Vulnerable to postoperative complications due to overuse and redevelopment of significant joint laxity.

- Does not address the clinical problem we see with chronic, partial CCL tear without significant instability.  In this subpopulation, an extra-capsular technique is as effective as a simple debridement via either arthrotomy or arthroscopy and placement of stabilizing tape or suture serves only as preventative measure rather than treatment. 

Tightrope vs TTA/TPLO

The few scientific studies available so far have failed to detect differences between the two major types of repair. Although the tightrope CCL surgery offers specific advantages over the conventional lateral imbrication techniques, whether or not these features truly improve the procedure enough to win the dynamic (TTA, TPLO) vs. extra-articular stabilization debate, will remain to be seen.  Despite of the lack of evidence, most veterinary surgeons prefer TPLO or TTA to the lateral suture technique. We can only speculate why we found the TPLO or TTA subjectively superior to lateral suture technique in the everyday practice.

One of the explanations perhaps has to do with a commonly occurring clinical situation, specifically the chronic partial CCL tear.  As we pointed out earlier, for these patients the geometry-altering techniques make more sense.  Another reason may be related to the effect of physical therapy and postoperative care on the functional outcome.

Studies have shown that aggressive physical therapy has a significant ability to improve outcome following extra-capsular repair. While patient’s treated with TTA (or TPLO) would benefit form physical therapy as well, they do appear to recover more consistently without the use of extensive rehabilitation.  Although physical therapy would be a great addition to recovery from just about any orthopedic procedures, most pet owners due to many practical reasons, do not pursue it. 

Bottom Line:

The Tightrope CCL repair is a version of the lateral imbrication procedure with definite advantages.  Although we continue to favor TTA in treating CCL disease due to the fact that a large percentage of our patients have chronic disease with only minimal or no instability. At the same time, a minimally invasive, new and improved extracapsular procedure may provide an attractive alternative for the right patient.

The Tightrope procedure is now available as an option for treatment of cranial cruciate ligament tear at the Veterinary Surgical Specialists of Orange County.