Rehabilitation Guidelines for Autologous Chondrocyte Implantation Ashley Conlin, PT, DPT, SCS, CSCS Objectives Review ideal patient population Review overall procedure for Autologous Chondrocyte Implantation Discuss general principles of rehabilitation Identify stages of healing Identify post-operative rehabilitation guidelines for Patellofemoral or Femoral Condyle Autologous Chondrocyte Implantation 1
Prevalence of Chondral Defects According to an article from Med Sci Sports Exercise in 2010, full thickness focal chondral defects are present in 36% of athletes. 37% in the patellofemoral compartment 35% on the femoral condyles 25% on the tibial plateau Limited ability for spontaneous repair of the cartilage is well documented Lack of vascularization of the cartilage prevents healing According to several articles, athletes with chondral damage are 12 times more likely to develop knee osteoarthritis Prevalence of Chondral Defects 2
Ideal Candidates for the ACI Procedure Factors affecting success of ACI Procedure Age BMI Duration of pre-operative symptoms Prior history of knee surgeries Chondral defect size Alignment, ligamentous and meniscal integrity Age As we age, our body has a decreased ability to regenerate tissue Generally, younger patients have less degenerative changes Because of this, the rehabilitation process is usually slower for older individuals 3
Body Mass Index BMI > 30: Patients with high BMI do not have as good of results as patients with a normal BMI Force does matter, BMI > 35 should not be implanted unless dealing with an athlete with high muscle tone Obesity and previous knee surgeries have the highest association of progression to OA Body Mass Index CDC Guidelines 18.5 24.9 25.0 29.9 30.0 or > Normal Overweight Obese *Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. Bethesda (MD): National Heart, Lung, and Blood Institute; September 1998 Body Mass Index 4
Duration of Symptoms - Prior History of Surgery Shorter DOS has been associated with improved postoperative clinical outcomes after ACI Acute injuries do better than chronic because of an improved healing environment Long-standing lesions may experience degeneration of the surrounding cartilage Clinical outcomes of 3 or more previous procedures result in the worst outcomes Defect Size Lesion size is a key factor in determining appropriate treatment Lesions < 2 cm2 vs defects 2 cm2 The relevance of defect size should be evaluated in relation to the patient s size and relative overall surface area of the weight-bearing condyle 5
Alignment, Ligamentous and Meniscal Integrity It is imperative to correct any alignment or ligamentous instability issues to prevent any problems with the new graft site. Many of these procedures are done either during the initial biopsy or during the implantation of cells. ACI Procedure Two step process 1. Arthroscopic evaluation and cartilage grafting from an area of limited weight-bearing Usually takes 3-6 weeks for the harvested cells to be cultured at a separate facility 2. Open procedure where the cells are implanted under a periosteal cover that is sutured over the cartilage defect Other procedures may be performed at the same time oligamentous repair, Meniscus and Re-alignment Procedures 6
Courtesy of Jason Scopp, MD 7
No snoozing allowed Grab that second cup of coffee if you need it! Principles of Rehabilitation: Establishing the optimal environment for healing Facilitating the repair process while avoiding too much stress to the graft site Cyclic compressive loading Enhances chondrogenesis and matrix synthesis CPM is commonly used to achieve this Controlled weight-bearing PWB is slowly progressed to FWB to gradually increase the load applied to the weight-bearing portion of the joint 8
Principles of Rehabilitation: Awareness of the Biomechanics of the Knee Constant articulation between the femoral condyles and tibialplateaus throughout knee ROM Full extension: Anterior femoral condyles articulate with the middle portion of the tibial plateaus Inferior margin of the patella articulates with the trochlea Greater knee flexion: Femoral condyles roll and slide posteriorly on the tibial plateaus Contact area between the patella-femoral joint moves proximal along the patella Knee Mechanics Principles of Rehabilitation: Awareness of the Biomechanics of the Knee Anterior femoral condyle lesions may be progressed into deeper degrees of knee flexion and inversely for posterior lesions Lesions on the non-weight-bearing surfaces, such as the trochlea, may include more rapid partial weight-bearing 9
Principles of Rehabilitation: Awareness of the Biomechanics of the Knee Avoid Arthrofibrosis! ROM exercises are started immediately post-operative Goal of 0 degrees of extension within a few days after surgery Use of CPM is common with patient using it 4-8 hours per day ROM goals and timelines will vary based on lesion location and surgeon preference Patellar mobilizations Soft tissue massage and scar management Muscle flexibility Principles of Rehabilitation: Minimizing Pain and Effusion Progressive decline in quadriceps function has been cited in various studies when excessive effusion is present Treatment options: Analgesics Cryotherapy Compression High-voltage Stimulation Ultrasound 10
Principles of Rehabilitation: Restoring Lower Extremity Muscle Function and Stability Electrical muscle stimulation and biofeedback are often used to facilitate the contraction of the quadriceps muscle This treatment can be used immediately post-operative per patient tolerance Although the quadriceps are of particular importance, total lower body strength and stability should be included Hip, pelvis, core and ankle The knee often falls victim to the imbalances from the joints above and below it Proprioceptive and Neuromuscular control activities Principles of Rehabilitation: Gradual Return to Weight-Bearing Activities Main goal is to avoid over-stressing the healing graft site Sagittal and frontal plane movements are generally initiated first, progressing to diagonal and rotational movements Double leg to single leg activities Use of orthotics, insoles or braces may be considered 11
Principles of Rehabilitation: Communication between the Sports Medicine Team Surgeon, Physical Therapist, Athletic Trainer, Coach, Parents and Patient are all involved Each patient, surgeon and surgical technique is different and proper communication is essential for optimum outcomes Education to the patient is key: Pre-operative PT visit can be used to prepare the patient both mentally and physically This rehabilitation requires dedication and patience Expectations after surgery Proliferation Phase (Weeks 0-6) Type I-II Collagen fibers begin forming within the defect Goals: Protect healing tissue from load and shear forces Decrease pain and effusion Restoration of full extension ROM Gradually improve knee flexion Restore quadriceps control 12
Proliferation Phase (Weeks 0-6) Weight-Bearing WB status based on lesion location, size and physician preference Femoral Condyle: NWB 1-2 weeks TTWB weeks 2-3 PWB weeks 4-5 Patellofemoral: Immediate TTWB brace locked in full extension 50% WB week 2 75% WB weeks 3-4 Proliferation Phase (Weeks 0-6) Range of Motion CPM Initiate CPM day 1 for 8-12 hours per day May continue CPM for 6-8 hours per day for 6 weeks Progress CPM 5-10 degrees per day Patellar mobilizations Hamstring and calf flexibility Femoral Condyle: Knee flexion goal of 90 degrees by 1-2 weeks, 120 degrees by 6 weeks Patellofemoral: Knee flexion goal of 90 degrees by 2-3 weeks, 120 degrees by 6 weeks 13
Proliferation Phase (Weeks 0-6) Strengthening Quadriceps setting Electrical Stimulation and/or biofeedback for Quadriceps exercises 4 way straight leg raises Stationary bike as ROM allows Initiate weight shifts for PF lesions at weeks 2-3 May begin aquatic therapy for gait re-education and exercise Transition Phase (Weeks 6-12) Matrix formation of Type II Collagen fibers with poor integration with underlying bone Goals Gradually increase ROM Improve Quadriceps strength and endurance Increase functional activities 14
Transition Phase (Weeks 6-12) Discontinue the brace at week 6 Weight-bearing Femoral Condyle: 50% BW at week 6, progressing to FWB at weeks 8-9 Patellofemoral: Progress to FWB at weeks 6-8 Transition Phase (Weeks 6-12) Range of Motion: Maintain full knee extension Progress knee flexion to 125-135 degrees by week 8 Continue flexibility program Patellar and soft tissue mobilizations 15
Transition Phase (Weeks 6-12) Strengthening Initiate weight shifts for femoral condyle lesions Leg Press 7-8 weeks Minisquats 0-45 degrees by 8 weeks Balance and proprioception drills Front lunges, wall squats, front and lateral step ups 8-10 weeks Stationary bike with resistance Treadmill walking program Use of E-stim and aquatic therapy as needed Remodeling Phase (Weeks 12-26) Ongoing matrix formation with integration to bone and adjacent host cartilage Goals Improve muscular strength and endurance Increase functional activities Full range of motion Full weight-bearing with normal mechanics 16
Remodeling Phase (Weeks 12-26) Strengthening Leg Press (0-90 degrees) Squats (0-60 degrees) Step ups, progressing to an 8 step Forward lunges Bike, stairmaster, swimming Elliptical Maturation Phase (Weeks 26-52) Repaired tissue reaches its full maturation with complete filling of the defect Goals Gradual return to full unrestricted functional activities Strength within 80-90% of the uninvolved lower extremity No pain or swelling 24 Months Post Implantation Pictures Courtesy of Tom Minas and Scott Gillogly 17
Maturation Phase (Weeks 26-52) Strengthening Continue maintenance program 3-4 times per week Progress agility and balance activities Impact programs should be individualized to the patient Generally low impact sports are allowed at 6 months o Swimming, skating and cycling Higher impact sports may be allowed at 8-9 months for smaller lesions, 9-12 months for larger lesions o Running and Aerobics High impact sports are allowed at 12-18 months o Tennis, basketball, football and baseball Maturation Phase (Weeks 26-52) Please remember that the ACI procedure is designed to return the patient to NORMAL function. Precaution must be exercised when attempting to return a patient to higher level, higher impact activities. Even though return to competitive athletics has been documented, we must consider the overall integrity and longevity of the joint. Patient education on this topic is crucial. 18
References Reinold et al. Current Concepts in the Rehabilitation Following Articular Cartilage Repair Procedures in the Knee. Journal of Orthopaedic and Sports Physical Therapy 2006; 36 (10): 774-794 Flanigan et al. Prevelence of Chondral Defects in Athlete s Knees: a Systematic Review. Med Sci Sports Exerc. 2010; 42: 1795-1801 Edwards et al. Clinical Rehabilitation Guildlines for Matrix-Induced Autologous Condrocyte Implantation on the Tibiofemoral Joint. Journal of Orthopaedic and Sports Physical Therapy 2014; 36 (2): 102-119 Ebert et al. Traditional vs Accelerated Approaches to Post-operative Rehabilitation following MatrixInduced Autologous Chondrocyte Implantation (MACI): Comparison of Clinical. Biomechanical and Radiographic Outcomes. Osteoarthritis and Cartilage 2008; 16: 1131-1140 Mithhoefer et al. Current Concepts for Rehabilitation and Return to Sport After Knee Articular Cartilage Repair in the Athlete. Journal of Orthopaedic and Sports Physical Therapy 2012; 42 (3): 254273 McNickle AG, et al. Am J Sports Med 2009;37:1344-1350 Feder J, et al. Tissue Engineering in Musculoskeletal Clinical Practice; Chapter 22:219-226 Krishnan et al. JBJS (Br) 2006;88(1);61-64. Saris et al. Am J Sports Med 2009; 37 Suppl 1:10S-19S Thank You! 19