Contrary to popular perception, not all pelvic limb lameness in dogs is joint-related, i.e., a “bad hip” or a “blown cruciate.” Definitive diagnosis is crucial, especially before pursuing surgery for the presumptive problem.1-5 Advanced imaging can help, as can arthroscopy, but neither method reveals soft tissue pain as a common source of the tension and altered gait in dogs. Only hands-on touch and informed palpation can “image” this source of discomfort and possible precursor to cruciate rupture. In light of this uncertainty of why a dog unweights a limb or displays caudal end weakness,6 clients who call a referral center for an evaluation are surprised when the receptionist asks them to set aside a surgery date.7 Even with a busy cutting schedule, why wouldn’t an orthopedic practice consider conservative care first? Tragically, some caregivers have complained of having to choose between only two options: costly reconstructive surgery or euthanasia. These caregivers are browbeaten into believing that if they refuse surgery, their dogs will without question suffer painful debilitation from arthritis.8 Is there not a kinder, gentler way? Different Viewpoints Opinions on the cause of lameness and what to do about it can vary as widely across town as they do inside institutions of higher learning.9 Whereas one group may routinely advocate surgery and little else, another may prescribe a program that starts with preventive nutritional approaches and exercise for at-risk breeds. The latter approach would continue with multimodal methods to maintain or restore joint and whole body health. This includes building structural support not only in the joint but in the extra-articular structures as well, routine soft tissue assessments to detect early signs of muscle strain and biomechanical compensation, along with regular physical medicine treatments such as acupuncture and massage to restore and balance proprioception and proper weight distribution.10 Should the patient indeed require surgery, his recovery period can differ dramatically, depending on pre-, peri- and post-operative pain pre-emption and physical medicine measures. While some dogs may still be sentenced to weeks in claustrophobic cage confinement with a few pain pills as the sole analgesia, this restrictive, counterproductive prescription is becoming obsolete. Modern guidelines for veterinary analgesia acknowledge that post-surgical pain is frequently overlooked.11 Orthopedic procedures, in particular, “can cause severe and prolonged pain.” In addition to pharmacologic interventions for multimodal analgesia, nonpharmacologic methods of pain relief help by supporting recovery and regaining function. That said, can the problem and the need for surgery be averted entirely? Many veterinarians acknowledge a “fundamental gap in the current understanding of the cellular and molecular events that lead to CCL rupture in dogs.”12 Thus, in contrast to human anterior cruciate ligament (ACL) injury, usually associated with history of trauma, CCL disease in dogs may develop as “the final stage of a progressive condition associated with an idiopathic, probably immune-mediated, inflammatory arthropathy.”13 Other Options? Considering its long course of development, might dogs avoid CCL rupture through physical medicine approaches delivered much earlier in their lives, before the ligament gives way to disease and its ultimate demise? Would soft tissue palpation, if included routinely in physical examinations, reveal somatic dysfunction indicative of aberrant proprioceptive function in the joint and quadriceps muscles? Could physical medicine procedures such as medical acupuncture, therapeutic exercise and massage normalize proprioception and limit decay of the ligament due to eccentric or joint loading? Would interventions such as acupuncture, which reduces spinal cord wind-up and peripheral sensitization, stop or reduce the contribution of neurogenic inflammation that leads to tissue breakdown? Might a more enlightened, proactive, health-maintaining outlook for veterinary medicine save dogs not only the trauma and pain of surgery (and clients the associated costs), but also the potential complications such as TPLO failure, meniscal damage14, or rupture of the contralateral CCL, which can happen in as many as 60 percent of cases?15 Perhaps it is time for veterinary medicine to consider shifting many of its long-held clinical paradigms, beginning with pelvic limb lameness in dogs. What Else Could It Be? Risk factors, such as proprioceptive function of the joint and quadriceps muscle group, are becoming better recognized in humans.16 Proprioceptive deficits are finally beginning to receive attention concerning the etiopathogenesis canine CCL disease, but unless veterinarians learn to assess myofascial dysfunction with their hands, they will miss it every time.17 As is likely the case with most veterinary surgeons, human physicians specializing in the diagnosis of musculoskeletal pain and dysfunction “are seldom as well-trained in recognizing and managing myofascial pain as they are other soft-tissue pain problems.”18 Ordinarily, the soft tissue contribution to pain is either an afterthought or omitted altogether from the diagnostic algorithm. Joint pain interferes with mechanoreception. Early work from the osteopathic medical field revealed relationships between muscle pain, proprioceptive abnormalities and joint dysfunction.19 Myofascial dysfunction, trigger points and taut bands can refer pain to the knee or stifle joint as well as cause the knee to buckle, lock or otherwise function incorrectly.20,21 Rehabilitation and therapeutic exercise are acknowledged means of neuromuscular re-education that can improve coordination and strength through mechano- and proprioceptor stimulation.22 Beyond the fact that addressing soft tissue pain is simply good medicine, studies have shown that up to 95 percent of human patients treated for pain show a myofascial component.23 Trigger points in the quadriceps group can cause pain in the cranial portion of the knee or stifle. In the hamstring and popliteus muscles, they can create caudal knee pain, and restriction in the tensor fasciae latae and iliotibial band may lead to lateral stifle pain.24 In other words, myofascial trigger points can cause pelvic limb lameness and proprioceptive deficits. Over time, dynamic instability of the stifle joint secondary to aberrant proprioception may place excessive stress on ligaments. Whether due to mechanical strain or persistent pain, the joint may be affected by neurogenic inflammation and peripheral sensitization, culminating in ligament failure. There’s a Dog Attached to That CCL, Doctor Whatever the cause, most dogs with pelvic limb lameness exhibit myofascial dysfunction or alterations in posture and weight bearing. Sometimes, treating the trigger points delivers marked improvement in weight bearing. If the CCL has ruptured, it is not a surgical emergency. Why not offer the client a course of conservative care and reassess? The message from the human medical literature states, “All acute ACL injuries should undergo a formal course of rehabilitation, whether reconstruction is to be pursued or not.”25 Moreover, “Most surgeons with ACL experience would agree that a stable but stiff knee is far worse for a patient than an unstable knee with a good range of movement.”26 The need for a new paradigm concerning the prevention and treatment of pelvic limb lameness becomes obvious considering that postoperative complications can include, but are not limited to, bone fracture, long-term pain, infection, hardware complications, neurovascular complications, and development of complex regional pain syndrome, nerve irritation and loss of joint motion.27 As veterinary medicine follows its human counterpart into ever-more technologically advanced territory, clinicians risk missing diagnoses and misdiagnosing patients by skipping elements of the physical examination. One can only find trigger points and myofascial pain by palpating. The take-away message? Palpate early and palpate often. Learn the language of myofascial strain and what the lineup of trigger-point pathology indicates through its distribution. It may end up saving dogs a lifetime of discomfort. Dr. Robinson, DVM, DO, Dipl. ABMA, FAAMA, oversees complementary veterinary education at Colorado State University. FOOTNOTES 1. Powers MY, Martinez SA, Lincoln JD, et al. Prevalence of cranial cruciate ligament rupture in a population of dogs with lameness previously attributed to hip dysplasia: 369 cases (1994-2003). J Am Vet Med Assoc. 2005;227:1109-1111. 2. Marx RG, Jones EC, Angel M, et al. Beliefs and attitudes of members of the American Academy of Orthopaedic Surgeons regarding the treatment of anterior cruciate ligament injury. Arthroscopy: The Journal of Arthroscopic and Related Surgery. 2003;19(7):762-770. 3. Powers MY, Martinez SA, Lincoln JD, et al. Prevalence of cranial cruciate ligament rupture in a population of dogs with lameness previously attributed to hip dysplasia: 369 cases (1994-2003). J Am Vet Med Assoc. 2005;227:1109-1111. 4. Barrett E, Barr F, Owen M, et al. A retrospective study of the MRI findings in 18 dogs with stifle injuries. J Small Animal Practice. 2009;50:448-456. 5. Fox DB. Ten ways to improve your orthopedic examination. Today’s Veterinary Practice. 2011;1(2): 33-36. 6. Carobbi B and Ness MG. Preliminary study evaluating tests used to diagnose canine cranial cruciate ligament failure. J Small Animal Practice. 2009;50:224-226. 7. Personal communication with clients, January 2012. 8. Personal communication with clients, November 2010. 9. Personal observation of the author. 10. Cook JL. Cranial cruciate ligament disease in dogs: biology versus biomechanics. Veterinary Surgery. 2010;39:270-277. 11. Hellyer P, Rodan I, Brunt J, et al. AAHA/AAFP pain management guidelines for dogs cats. J Am Anim Hosp Assoc. 2007;43:235-248. 12. Barrett JG, Hao Z, Graf BK, et al. Inflammatory changes in ruptured canine cranial and human anterior cruciate ligaments. Am J Vet Res. 2005;66:2073-2080. 13. Barrett JG, Hao Z, Graf BK, et al. Inflammatory changes in ruptured canine cranial and human anterior cruciate ligaments. Am J Vet Res. 2005;66:2073-2080. 14. Barrett E, Barr F, Owen M, et al. A retrospective study of the MRI findings in 18 dogs with stifle injuries. J Small Animal Practice. 2009;50:448-456. 15. Cook JL. Cranial cruciate ligament disease in dogs: biology versus biomechanics. Veterinary Surgery. 2010;39:270-277. 16. Logerstedt DS, Snyder-Mackler L, Ritter RC, et al. Knee stabilitiy and movement coordination impairments: Knee ligament sprain: Clinical practice guidelines linked to the international classification of functioning, disability, and health from the Orthopaedic Section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2010;40(4):A1-A37. 17. Comerford EJ, Smith K, Hayashi K. Update on the aetiopathogenesis of canine cranial cruciate ligament disease. Vet Comp Orthop Traumatol. 2011;24:91-98. 18. Bennett R. Myofascial pain syndromes and their evaluation. Best Practice Research Clinical Rheumatology. 2007;21(3):427-445. 19. Knutson GA. Dysafferentation: a novel term to describe the neuropathological effects of joint complex dysfunction – a look at likely mechanisms of symptom generation. [Letter}. J Manipulative and Physiological Therapeutics. 1999;22(7):491-492. 20. Travell JG and Simons DG. Myofascial Pain and Dysfunction. The Trigger Point Manual. Volume 2. The Lower Extremities. Baltimore: Williams & Wilkins, 1983. 21. Sheehan FT, Borotikar BS, Behnam AJ, et al. Alterations in in vivo knee joint kinematics following a femoral nerve branch block of the vastus medialis: Implications for patellofemoral pain syndrome. Clinical Biomechanics. January 13, 2012. [Epub ahead of print]. 22. Cook JL. Cranial cruciate ligament disease in dogs: biology versus biomechanics. Veterinary Surgery. 2010;39:270-277. 23. Bennett R. Myofascial pain syndromes and their evaluation. Best Practice Research Clinical Rheumatology. 2007;21(3):427-445. 24. Bennett R. Myofascial pain syndromes and their evaluation. Best Practice Research Clinical Rheumatology. 2007;21(3):427-445. 25. Unwin A. (iii) What’s new in anterior cruciate ligament surgery? Mini-Symposium. Soft Tissue Surgery in the Knee. Orthopedics and Trauma. 2010:24 (2): 100-106. 26. Unwin A. (iii) What’s new in anterior cruciate ligament surgery? Mini-Symposium. Soft Tissue Surgery in the Knee. Orthopedics and Trauma. 2010:24 (2): 100-106. 27. Unwin A. (iii) What’s new in anterior cruciate ligament surgery? Mini-Symposium. Soft Tissue Surgery in the Knee. Orthopedics and Trauma. 2010:24 (2): 100-106. <HOME>
