2020 Fundamental Principles of Rehabilitation and Musculoskeletal Tissue Healing PDF

Received: 3 February 2019 Revised: 11 April 2019 Accepted: 26 May 2019 DOI: 10.1111/vsu.13270 REVIEW Fundamental principles of rehabilitation and musculoskeletal tissue healing Kristin Kirkby Shaw DVM, MS, PhD, CCRT, DACVS, DACVSMR1 | Leilani Alvarez DVM, CVA, CCRT, DACVSMR2 | Sasha A....

Received: 3 February 2019 Revised: 11 April 2019 Accepted: 26 May 2019 DOI: 10.1111/vsu.13270 REVIEW Fundamental principles of rehabilitation and musculoskeletal tissue healing Kristin Kirkby Shaw DVM, MS, PhD, CCRT, DACVS, DACVSMR1 | Leilani Alvarez DVM, CVA, CCRT, DACVSMR2 | Sasha A. Foster MSPT, CCRT3 | Julia E. Tomlinson BVSc, MS, PhD, CCRP, CVSMT, DACVS, DACVSMR4 | Aaron J. Shaw OTR/L, CHT, CSCS5 | Antonio Pozzi DVM, MS, DACVS, DECVS, DACVSMR6 1 Department of Rehabilitation and Sports Medicine, Animal Surgical and Orthopedic Abstract Center and Sound Veterinary Rehabilitation Objective: To review fundamental principles of tissue healing and physical rehabilita- Center, Shoreline, Washington tion as they apply to dogs recovering from cranial cruciate ligament (CCL) surgery. 2 Department of Integrative and Study design: Invited Review. Rehabilitative Medicine, The Animal Medical Center, New York, New York Sample population: None. 3 Department of Orthopedic Medicine and Methods: A multidisciplinary group of specialists in small animal surgery, rehabilitation/ Mobility, Colorado State University, Fort sports medicine, and human physical and occupational therapy reviewed the cur- Collins, Colorado 4 rently available evidence for rehabilitation post-CCL surgery. Because current evi- Department of Rehabilitation and Sports Medicine, Twin Cities Animal dence is limited, this group proposes guidelines for rehabilitation after CCL surgery Rehabilitation Clinic, Minneapolis, based on the fundamental principles of tissue healing and physical therapy. Minnesota Results: This Review proposes four fundamental principles of small animal physical 5 Department of Physical and Occupational Therapy, MoveMend Physical and rehabilitation based on the foundations of tissue healing and patient-centric and goal- Occupational Therapy, Seattle, Washington oriented therapy. Postoperative rehabilitation programs should be designed such that 6 Department of Small Animal Surgery, patient progress is based on individual assessment according to the degree of tissue University of Zurich, Zurich, Switzerland healing, strength, and achievement of functional goals. Therapists must fully under- Correspondence stand phases of tissue healing, reassess the patient frequently, and use clinical reason- Kristin K. Shaw, 14810 15th Ave NE, ing skills to progress treatment appropriately for the individual patient. Shoreline, WA 98155. Conclusion: Until more robust evidence is available to guide treatment protocols, Email: [email protected] fundamental principles of rehabilitation should ideally be adhered to when provid- ing rehabilitation, including after CCL surgery. Clinical significance: While this Review specifically addresses post-CCL surgery rehabilitation, these fundamental principles should be applied broadly to animals enrolled in rehabilitation programs. 1 | INTRODUCTION The benefits of postoperative rehabilitation after cranial cruciate The results of this work were presented at the Veterinary Orthopedic ligament (CCL) surgery have been reported in several arti- Society meeting; February 9-16, 2019; Breckenridge, Colorado. cles.1-6 The lack of large, randomized, prospective studies This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2019 The Authors. Veterinary Surgery published by Wiley Periodicals, Inc. on behalf of The American College of Veterinary Surgeons. 22 wileyonlinelibrary.com/journal/vsu Veterinary Surgery. 2020;49:22–32. KIRKBY SHAW ET AL. 23 comparing cohorts treated with and without postoperative applying therapeutic techniques in a scientific and clinically rehabilitation makes it difficult to give conclusive recom- reasonable manner. Furthermore, veterinary surgeons should mendations. While the initial data are supportive, there is a appreciate the opportunities that rehabilitation therapy (when significant requirement for larger studies investigating the following these principles) may provide for their patients. role of rehabilitation after CCL surgery. Furthermore, for long-term, multicenter, prospective studies to identify pre- dictors of successful outcome after CCL surgery, a standard- 2 | PRINCIPLE 1 ized approach to postoperative rehabilitation in dogs should Tissues follow a predictable pattern of healing be adopted. Each phase overlaps, and the duration of each phase var- As a primary step toward developing rehabilitation proto- cols for testing in multicenter clinical trials, we have reviewed ies depending on tissue type.7,8 Rehabilitation therapists the fundamental principles of physical rehabilitation as they must thoroughly understand these phases as they relate to apply to tissue healing after CCL surgery. We propose four therapeutic interventions (Table 1). basic principles of rehabilitation built around the phases of tis- Minimizing surgical trauma with accurate soft tissue han- sue healing and the specific goals of CCL surgery. Cranial cru- dling will facilitate the initial phase of healing and joint ciate ligament surgical treatments seek to reestablish normal neuroadaptation. The rehabilitation therapist will personalize joint kinematics, resolving pain and returning the patient to full strategies to support the healing phases on the basis of type function. While pain relief and improvement of function are of surgical technique and according to the response of the well established goals of musculoskeletal rehabilitation, spe- patient to surgery. cific techniques can be adopted to improve neuroadaptation and selective muscular strengthening in the CCL surgical 2.1 | Phases of musculoskeletal tissue healing patient, seeking to improve joint kinematics. Rehabilitation therapists must understand these principles and use clinical rea- 2.1.1 | Acute (inflammatory) soning skills when choosing and modifying therapeutic inter- The acute phase of wound healing is characterized by gross ventions based on acuity of injury and functional assessment of signs of inflammation, including heat/warmth, erythema, the individual animal. In addition, understanding the physio- pain, and swelling. On a cellular level, this phase includes logic effects of the CCL injury and of the surgery on the stifle migration of platelets and leukocytes to the site(s) of injury itself and on the rest of the body will help define the specific with release of degradative proteases, inflammatory proteins, goals of post-CCL rehabilitation (Figure 1). and immunomodulatory cytokines.7 During this phase, the This Review presents the four fundamental principles of biomechanical strength of the wounded tissue is weak, with veterinary rehabilitation, their relevance to dogs with CCL strength provided by suture and fibrin within the blood clot.8 insufficiency, and the specific goals of rehabilitation after CCL surgery. These principles should also apply to rehabili- This phase typically lasts approximately 72 hours after tation of other musculoskeletal conditions. This Review is wounding/surgery.7 intended to assist veterinary rehabilitation therapists with 2.1.2 | Subacute (proliferative/reparative) This stage of healing is characterized by angiogenesis, fibroplasia, increased collagen production, and epitheliza- tion. Early in the proliferative phase, granulation tissue fills any tissue defects (cutaneous wounds and deeper tissues). Early granulation tissue does not provide substantial gain in wound strength and includes provisional type III collagen.7 As fibroblasts migrate into the wounded tissue, the provi- sional extracellular matrix is replaced by type I collagen.7 Typically, the fastest rate of gain in wound strength occurs between 7 and 14 days postinjury, although final or com- plete regain of strength is not expected in this time period FIGURE 1 The initial cranial cruciate ligament injury and its for musculoskeletal tissue.7,8 It is also important to recog- surgical treatment result in physiologic changes affecting the nize that CCL surgeries involve healing of various tissues, musculoskeletal and nervous systems, both locally and peripherally. with different rates of gain in wound strength. A clear under- Therapists must design treatment plans that address the entire body standing of the rate of tissue strengthening during healing is  24 TABLE 1 Examples of specific physical rehabilitation strategies based on stages of tendon-fascia healing Healing stage Cellular phase Physical characteristics Therapeutic intervention Inflammatory stage Vasodilation, invasion of platelets and inflammatory Edema, erythema, warmth, pain Cryotherapy, ideally with compression cells (neutrophils, monocytes and macrophages); NSAID (unless contraindicated) chemical mediators include histamine, bradykinin, Manual therapy (joint distractions, compressions) PGE2 Wound strength depends on provisional clot and Modalitiesa: electrical stimulation, laser therapy, sutures ultrasound, PEMF, ESWT Fibroblastic stage Growth factors (TGF- β1, BMP, CTGF) activate Subsidence of markers of inflammation Manual therapy: passive ROM, soft tissue fibroblastic cells, which proliferate and produce mobilization, joint mobilization elements of ECM; collagen fibers are initially Modalitiesa: electrical stimulation, laser therapy, randomly organized, forming a scar tissue ultrasound, PEMF, ESWT Therapeutic exercise: prescribed to meet goal of full weight bearing on the surgical limb while continuing to protect tissues Wound beginning to gain tensile strength Continued pain management Remodeling stage Remodeling of the scar improves the organization Inflammation should be resolved; pain, if present, Manual therapy as required based on patient and mechanical properties of the ECM; ongoing may be due to osteoarthritis, DOMS, reinjury of assessment of surgical limb and rest of body; synthesis of collagen leads to tendon scar and healing tissue passive ROM, soft tissue mobilization including adhesions scar mobilization, joint mobilization Modalities: generally discontinued in this phase unless patient assessment indicates specific requirement at surgical limb or rest of body Therapeutic exercise: prescribed to increase active ROM and flexibility, build muscle strength and endurance, improve proprioception, improve cardiovascular fitness Abbreviations: BMP, bone morphogenetic protein; CTGF, connective tissue growth factor; DOMS, delayed onset muscle soreness; ECM, extracellular matrix; ESWT, extracorporeal shockwave therapy; NSAID, nonsteroidal anti-inflammatories; PEMF, pulsed electromagnetic field therapy; PGE2, prostaglandin E2; ROM, range of motion; TGF- β1, transforming growth factor-β1. a Limited clinical evidence in veterinary patients exists for these modalities at this time. KIRKBY SHAW ET AL. KIRKBY SHAW ET AL. 25 particularly important for surgical techniques that rely on 2.2 | Time to return to approximate normal periarticular fibrosis to provide passive stabilization. strength 2.2.1 | Skin 2.1.3 | Chronic (maturation/ remodeling) Incised wounds that are well apposed (sutured) should achieve complete epithelization in 24 to 48 hours. If there is no gap This phase represents remodeling of collagen and connective formation, adequate strength is expected at 10 to 14 days (typi- tissue and contraction of the scar. Collagen continues to be cal time for suture removal), although ultimate strength many deposited at a slower rate than in the proliferative phase.7 Col- never reach 100% (see Table 2).7,8 lagen/connective tissue remodels on the basis of on the stresses placed on it (eg, Wolff's Law), so application of con- trolled external forces in the normal weight-bearing planes is 2.2.2 | Muscle essential for optimal maturation of connective tissue.8 How- Depending on the degree of gap between fibers and the degree ever, this tissue remains weaker than uninjured tissue until full of injury, muscle may take 6 weeks to 6 months to regain healing is achieved. Bone is expected to achieve complete approximately normal strength. The ultimate strength, flexibil- healing and 100% strength, although other musculoskeletal ity, and susceptibility to reinjury of muscle is directly related to tissues may never achieve maximal strength if scar (fibrous) scar/fibrous tissue interposed between healing fibers. tissue remains unorganized within the wounded region.8 Reli- ance on scar or fibrosis for mechanical stability will result in reduced strength and could predispose to repeated injury. 2.2.3 | Tendon, ligament, fascia Increase in mechanical strength of tissue takes months or even Tendon, ligament, and fascial tissues are generally less vas- years.8 cular, and healing is expected to take up to 1 year to TABLE 2 Approximate rates of tissue healinga Tissue and grades of injury 0–3 d 4–14 d 3–4 wk 5–7 wk 2–3 mo 3–6 mo 6–12 mo >1 year Skin SQ Fascia Muscle DOMS (exercise induced) Grade 1 Grade 2 Grade 3 Tendon Acute Subacute Chronic Rupture/surgical repair Ligament (extra-articular) Grade 1 Grade 2 Grade 3 Intra-articular Unlikely to fully heal Bone Abbreviations: DOMS, delayed onset muscle soreness; SQ, subcutaneous. a Expected time frame for tissue healing after injury. Rate of healing is influenced by the degree of tissue damage (Grade), particularly with muscle, tendon, and ligament injury. Muscle: Grade 1, mild damage (