Originally published by June 2015 issue of Veterinary Practice News As someone who offers her thoughts on veterinary topics in print and online quite often, Narda G. Robinson, DO, DVM, MS, FAAMA, hears a great deal from pet owners and fellow practitioners about cranial cruciate ligament disease, a common aliment that can greatly impact a pet’s mobility and lifestyle. Just don’t try and tell her surgery is the “gold standard” for treating CCL disease. Nor should surgery always be presented as the best treatment, said Dr. Robinson, director at the CSU Center for Comparative and Integrative Pain Medicine at Colorado State University Veterinary Teaching Hospital. “My first question is: ‘What constitutes a ‘gold standard?’” Robinson said. “Is this based on opinion or scientific evidence? I’d prefer to see whatever is a ‘gold standard’ supported by evidence of benefit, safety and the least invasive approach possible rather than often-held opinions.” She noted that there are many instances of pelvic limb lameness that don’t require surgery, yet there isn’t enough evidence to say how a comprehensive rehabilitation program compares to various surgical outcomes for cruciate injury. “Based on what I’ve seen and heard from folks around the country, and even from other countries, there is oftentimes lack of clarity about what is causing a pelvic limb lameness prior to surgery,” she said. “It’s not always a damaged cruciate ligament.” Depending on what the problem entails, Robinson said the options are numerous: acupuncture, massage, laser therapy, therapeutic exercise, weight loss for obese dogs, pharmaceuticals and supplements. Old Study Points to Weight Amy S. Kapatkin, DVM, MS, Dipl. ACVS, said surgery is recommended but that certain patients will do OK without it. “It is not that surgery is not recommended, instead there are certain patients that may do fine without surgery,” said Dr. Kapatkin, professor of orthopedic surgery and section chief at University of California Davis School of Veterinary Medicine. In a study performed in the 1980s, “Clinical Results Following Nonoperative Management for Rupture of the Cranial Cruciate Ligament in Dogs,” 85 dogs diagnosed with a CCL rupture and were managed by restricting activity for three to six weeks, and weight loss if indicated, as well as analgesic medication as needed. The study, by P. B. Vasseur, DVM, Dipl. ACVS, showed 24 of 28 dogs that had a body weight of 33 pounds were considered to be clinically normal or improved after an average follow-up period of 36 months. Lameness in the remaining four dogs persisted or worsened over an average period of roughly eight months, and surgical replacement of the cruciate ligament was performed. Eleven of 57 dogs that had a body weight of 33 pounds or greater were classified as normal or improved after an average follow-up period of nearly 50 months. Lameness in the remaining 46 dogs persisted or worsened over an average period of roughly 10 months, and surgical replacement of the cruciate ligament was performed. “It is important to note that the follow-up had no objective measurements of the dogs and many were smaller breed dogs,” Kapatkin said. “It’s possible CCL disease has changed over the last 20 years – it appears to have clinically. So although we cite this paper a lot, it’s old literature and unknown how it would turn out in clinical trials.” Recommendations Brenda S. Kennedy, DVM, MS, with Canine Companions for Independence, said in some cases surgery may not be recommended for patients that have concurrent conditions that make them a poor candidate for anesthesia. “Physical therapy can be performed to help with dynamic stabilization of the stifle by improving musculoskeletal strength in the affected limb,” Dr. Kennedy said. “Management of pain through medication, Adequan injections, and other therapies, such as lasers or acupuncture, can help reduce the discomfort. These treatments are viable options for patients who cannot have surgery and can be very helpful to dogs post-surgery.” Like other experts, Kennedy emphasized the importance of weight management. Kennedy, who works with assistance dogs that tend to be susceptible to CCL disease because of their breed, also noted that surgery means downtime for these working pets, so she places a heavy emphasis on preventative measures. “Since we only train Labrador retrievers, golden retrievers and crosses of the two, we have a population of dogs that are susceptible to cruciate ligament tears,” she said. “This is one of the reasons why we stress to our volunteers and graduates the importance of maintaining a lean body mass in these dogs from a young age – currently, it is one of our best tools for prevention.” However, once it develops, getting on top of CCL disease quickly seems to be crucial. According to the American College of Veterinary Surgeons, 40 to 60 percent of dogs that have CCL disease in one knee will develop a similar problem in the other knee at some point. Rupture of the CCL is one of the most common reasons for hind limb lameness, pain and subsequent knee arthritis, according to ACVS. ACVS states that surgery is typically the best treatment for CCL, because it is the only way to permanently control instability in the knee joint. Michael P. Kowaleski, DVM, Dipl. ACVS, Dipl. ECVS, professor of orthopedic surgery at Cummings School of Veterinary Medicine at Tufts University, agrees with that assessment. “Surgery is generally the best option, since CCL deficiency results in instability that cannot be corrected medically,” Dr. Kowaleski said. Simon Roe, BVSc, PhD, Dipl. ACVS, a professor in small animal orthopedic surgery at the North Carolina State University Randall B. Terry Companion Animal Veterinary Medical Center, says the size of the animal may be key in deciding whether to treat surgically or non-surgically. “There are dogs that tear their CCL insidiously and don’t show lameness, so there does seem to be a group of dogs that are may be quite comfortable without surgery,” Dr. Roe said. For that reason, dogs weighing less than 33 pounds are more likely to undergo successful non-surgical management, Roe said. “It is also helpful if the dog is thin and if they are not expected to be active,” he said. “The risk is that these dogs could develop more significant lameness later in life. Also, their comfort level may change if the medial meniscus tears and adds to the joint discomfort.” Approaches As Robinson has noted, a myriad of approaches are available to treat CCL. “In human medicine, the more conservative surgeons are recommending several weeks of rehabilitation and pain control before even considering surgery,” Robinson said. “Again, the folks I’ve talked to around the country frequently tell me that after they give the dog time to heal and supportive therapy, the dog’s lameness resolves. Not always, but many times.” Often when those pet owners return to the surgeon for a recheck, Robinson hears from them that the surgeon continues to lobby for surgery as a preventive measure. “Given the amount of chronic pain and dysfunction that may result from a highly invasive approach, such as the TPLO, I can’t see the justification in putting a dog through this traumatic experience in order to prevent a possible future lameness,” she said. “It doesn’t make sense.” Roe, with NCSU, said that while there are no studies he knows of on non-surgical management techniques, he has heard many stories. “There are multiple devices and procedures that come with all sorts of claims,” he said. “Hinged braces, laser therapy, stem cells and a host of other approaches are available, but there is no way to know if it will help your dog.” This is why Roe is calling for more studies into non-surgical treatments. “On the non-surgical side, unbiased studies are needed to really understand if there is a group of dogs with CCL tear that can do well with good conservative management,” he said. “These are not easy studies to do as there is huge variability in the CCL patient – size, activity level, disease process, etc.” More data is also of interested to Kennedy, with Canine Companions. She noted that intra-articular injections of stem cells or platelet rich plasma have been performed by some veterinarians for partial ACL tears. “The data to support the success of this modality is currently lacking,” Kennedy said. “One of the challenges in veterinary medicine is that we just do not have the resources to perform the phased clinical trials, with proper randomization and controls, to critically evaluate the benefit of various treatments, surgical or otherwise.” Euthanasia One non-scientific treatment factor that is often a consideration is a pet owner’s ability to pay for surgery, particularly because someone who cannot afford surgery may consider euthanasia to be the only available option. “Many of the caregivers who contact me based on the articles I’ve written tell me that the surgeon insisted that a TPLO was urgently needed in order for them to make the right and moral decision, and that if they delayed surgery, that horrible arthritis would ensue,” Robinson said. “I have not seen evidence that supports the contention that TPLO prevents arthritis from developing.” Asked if costs should be considered when reviewing the options, Roe responded: “Absolutely.” It’s the practitioner’s or the surgeon’s role to describe the options, expected outcomes and potential complications, as well as the costs, so the pet owners can balance all those factors into making a decision, Roe said. “One approach might be to choose a less expensive surgical option,” he said. “Most surgeons charge less for extracapsular procedures because the implant costs are lower, though many feel that the complication rate may be higher.” Given that Kowaleski, with Tufts University, believes surgery is generally the best option, he said it would be ideal if cost was never a factor. But that’s not the reality, he added. Activity restriction and anti-inflammatories are other options if the owner cannot afford surgery, he said.
