 
 
Rehabilitation Protocol for Osteochondral Autograft/Allograft 
Transfer System (OATS) Procedure 
  
This protocol is intended to guide clinicians through the post-operative course for OATS procedure, a method for 
autogenous/allograft hyaline cartilage resurfacing of full thickness chondral defects of the weightbearing areas of the 
femoral condyle. This protocol is time based (dependent on tissue healing) as well as criterion based. Additionally, the 
location of the surgery is critical to safeguard against potentially harmful forces early in the rehabilitation process. 
Specific intervention should be based on the needs of the individual and should consider exam findings and clinical 
decision making. The timeframes for expected outcomes contained within this guideline may vary based on surgeon’s 
preference, additional procedures performed, and/or complications. If a clinician requires assistance in the progression 
of a post-operative patient, they should consult with the referring surgeon. 
  
The interventions included within this protocol are not intended to be an inclusive list of exercises. Therapeutic 
interventions should be included and modified based on the progress of the patient and under the discretion of the 
clinician.  
  
Considerations for the Post-operative Rehabilitation of the OATS Procedure 
Many different factors influence post-operative rehabilitation outcomes, including location, size, depth, and 
containment of the lesion(s), as well as presence of concomitant injury. This protocol distinguishes between condylar 
and patellofemoral lesions as there are considerations unique to each. However, it is recommended that clinicians utilize 
their clinical judgment and collaborate closely with the referring physician throughout the rehabilitation process. 
 
PHASE I: IMMEDIATE POST-OP (0-6 WEEKS AFTER SURGERY) 
Rehabilitation 
Goals 
• Maintain strength and flexibility of uninvolved leg 
• Control post-operative swelling and pain 
• Respect weightbearing restrictions to protect surgical leg 
Weightbearing  
• Crutches and hinged knee orthosis locked in extension with ambulation for all lesions 
• Non-weightbearing for 2 weeks for all lesions  
• Initiation of partial weightbearing is dependent on the location, size, and condition of the 
recipient site. When the site is a posterior condylar lesion or a patellofemoral lesion, partial 
weightbearing is allowed at 2 weeks. When the recipient site is located antero-central, partial 
weightbearing is allowed at 2 weeks for a small defect, 3 weeks for a medium-sized defect, and 
at 4 weeks for a large defect. 
• Full weightbearing is allowed by 6-10 weeks depending on condition 
Interventions 
Swelling Management:  
• Ankle pumps 
• Ice, compression, elevation (check with MD re: cold therapy)  
• Retrograde massage   
 
Range of Motion/Mobility:  
• Continuous Passive Motion (CPM): Immediately post-operative, perform 6-8 hours/day.  
- Start at 0-60 degrees for condylar lesions and patellofemoral lesions <6 cm2. Start at 0-
40 degrees for patellofemoral lesions >6 cm2. Progress 5-10 degrees/day.  
- If no CPM, perform wall slides ~500 repetitions, 3x/day 
• Passive range of motion (PROM) and active-assisted range of motion (AAROM) facilitating knee 
flexion and extension in protected ranges of motion 
- Condylar lesions:  
▪ 
Week 2: 0-90 degrees 
 
 
▪ 
Week 3: 0-105 degrees 
▪ 
Week 4: 0-115 degrees 
▪ 
Week 5-6: 0-125 degrees 
- Patellofemoral lesions:  
▪ 
Week 2-3: 0-90 degrees 
▪ 
Week 4: 0-105 degrees 
▪ 
Week 5-6: 120 degrees 
• Hamstring and calf stretching with knee extended 
• Patellar mobilization 
 
Strengthening: 
• Quad sets 
- Functional electrical stimulation (as needed for trace to poor quadriceps control) 
NMES high intensity (2500 Hz, 75 bursts) supine knee extended 10 sec/50 sec, 10 
contractions, 2x/wk during sessions—use of clinical stimulator during session, consider 
home units distributed immediate post op 
• 4-way straight leg raise (SLR) 
• Active knee extensions 90-40 degrees for condylar lesions only  
• Resisted plantarflexion in long sitting   
 
Additional Therapeutic Exercise: 
• Upper body ergometer (UBE) 
 
Criteria to 
Progress 
• Minimal pain and swelling 
• Compliance with weightbearing restriction 
• Achievement of range of motion goals (see above) 
• Quad contraction with superior patella glide and full active extension 
• Able to perform SLR without extension lag 
 
 
PHASE II: INTERMEDIATE POST-OP (6-12 WEEKS AFTER SURGERY) 
Rehabilitation 
Goals 
• Protect surgical leg with appropriate weightbearing  
• Restore range of motion 
• Control swelling  
• Normalize gait 
Weightbearing 
• Crutches and hinged knee orthosis unlocked with ambulation 
• Progress to full weightbearing by Weeks 6-10 depending on condition  
Additional 
Interventions 
*Continue with 
Phase I 
interventions 
Range of Motion:  
• Discontinue CPM at 8 weeks 
• Continue with PROM and AAROM from 0-120 degrees 
• Active range of motion (AROM) in protected range of motion:   
- Condylar lesions: active knee extensions 0-90 degrees beginning at Week 8 
- Patellofemoral lesions: active knee extensions 0-30 degrees beginning at Week 12 
 
Strengthening: 
• Condylar lesions: 
- Mini squats 0-60 degrees at Week 8 
- Leg press 0-90 degrees at Week 10 
• Patellofemoral lesions:  
- Mini squats 0-45 degrees at Week 8 
- Leg press 0-60 degrees at Week 10 
• Glute bridges in protected range of motion depending on lesion location 
• Standing resisted knee flexion in protected range of motion as indicated 
• Clamshells 
• Standing calf raises  
 
 
 
Gait Training:  
• Weight shifting 
• Ambulation over level ground 
• Treadmill training  
 
Conditioning:  
• Stationary cycling 
• Water activities (upon wound closure and clearance from MD), with gradually increasing knee 
flexion, with gradual progression from freestyle to breast stroke or side kick  
Criteria to 
Progress 
• Full, pain-free active and passive range of motion 
• Typical gait pattern over level ground 
 
PHASE III: LATE POST-OP (3-5 MONTHS AFTER SURGERY) 
Rehabilitation 
Goals 
• Continue to protect surgical leg 
• Maintain full ROM  
• Safely progress strengthening   
• Promote proper movement patterns  
• Avoid post exercise pain/swelling  
• Avoid activities that produce pain  
Weight Bearing 
• Full weightbearing without hinged orthosis  
Additional 
Intervention 
*Continue with 
Phase I-II 
Interventions  as 
indicated 
Strengthening:  
• Squat to chair 
• Lumbopelvic strengthening: bridge & unilateral bridge, sidelying hip external rotation-
clamshell, bridges on physioball, bridge on physioball with roll-in, bridge on physioball 
alternating, hip hike 
*The following exercises to focus on proper control with emphasis on good proximal stability 
• Lateral lunges 
• Romanian deadlift 
• Single leg progression: partial weight bearing single leg press, slide board lunges: retro and 
lateral, step ups and step ups with march, lateral step-ups, step downs, single leg squats, single 
leg wall slides 
 
Balance/Proprioception:  
• Single leg standing balance (knee slightly flexed) static progressed to dynamic and level 
progressed to unsteady surface 
• Lateral step-overs 
• Joint position re-training 
• Perturbation training 
 
Conditioning: 
• Stationary cycling 
• Elliptical 
• Treadmill training (incline, decline, intervals)  
• Stair climber 
• Interval running program 
- Return to Running Program 
•  
Criteria to 
Progress 
• No effusion/swelling/pain after exercise 
• Normal gait 
• ROM equal to contralateral side 
• Joint position sense symmetrical (<5-degree margin of error) 
 
 
 
 
PHASE IV: TRANSITIONAL (5-6 MONTHS AFTER SURGERY) 
Rehabilitation 
Goals 
• Maintain full ROM 
• Safely progress strengthening  
• Promote proper movement patterns 
• Avoid post exercise pain/swelling 
• Avoid activities that produce pain at graft donor site  
Additional 
Intervention 
*Continue with 
Phase I-III 
interventions as 
indicated 
• Begin sub-max sport specific training in the sagittal plane 
• Bilateral partial weightbearing (PWB) plyometrics progressed to full weightbearing (FWB) 
plyometrics 
 
Criteria to 
Progress 
• No episodes of instability 
• Maintain quad strength 
• 10 repetitions single leg squat proper form through at least 60 deg knee flexion 
• Drop vertical jump with good control  
• KOOS-sports questionnaire >70% 
• Functional Assessment 
- Quadriceps index >80%; HHD or isokinetic testing 60d/s 
- Hamstrings ≥80%; HHD or isokinetic testing 60 d/s 
- Glut med, glut max index ≥80%  HHD 
 
 
PHASE V: EARLY RETURN TO SPORT ( 6+MONTHS AFTER SURGERY) 
Rehabilitation 
Goals 
• Safely progress strengthening   
• Safely initiate sport specific training program  
• Promote proper movement patterns  
• Avoid post exercise pain/swelling  
• Avoid activities that produce pain  
Additional 
Intervention 
*Continue with 
Phase II-IV 
interventions as 
indicated 
• Progress to plyometric and agility program (with functional brace if prescribed) 
- Agility and Plyometric Program 
 
Criteria to 
Progress 
• Clearance from MD and ALL milestone criteria below have been met 
• Completion jog/run program without pain/effusion / swelling 
• Functional Assessment 
- Quad/HS/glut index ≥90%; HHD mean or isokinetic testing @ 60d/s 
- Hamstring/Quad ratio ≥66% 
- Hop Testing ≥90% compared to contra lateral side, demonstrating good landing 
mechanics 
• KOOS-sports questionnaire >90% 
• International Knee Committee Subjective Knee Evaluation >93 
• Psych Readiness to Return to Sport (PRRS) 
 
 
PHASE VI: UNRESTRICTED RETURN TO SPORT (8-12 MONTHS AFTER SURGERY) 
Rehabilitation 
Goals 
• Continue strengthening and proprioceptive exercises  
• Symmetrical performance with sport specific drills  
• Safely progress to full sport 
Additional 
Interventions 
• Multi-plane sport specific plyometrics program  
• Multi-plane sport specific agility program  
• Include hard cutting and pivoting depending on the individuals’ goals 
 
 
*Continue with 
Phase II-V 
interventions as 
indicated 
• Non-contact practice→ Full practice→ Full play  
Criteria to 
Progress 
• Last stage, no additional criteria 
   Revised 12/2021 
 
Contact 
Please email MGHSportsPhysicalTherapy@partners.org with questions specific to this protocol 
References: 
 
1. 
Campbell, A., Pineda, M., Harris, J. and Flanigan, D., 2016. Return to Sport After Articular Cartilage Repair in Athletes’ Knees: A Systematic 
Review. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 32(4), pp.651-668.e1. 
2. 
Journal of Orthopaedic & Sports Physical Therapy, 2018. Knee Pain and Mobility Impairments: Meniscal and Articular Cartilage Lesions Revision 
2018: Using the Evidence to Guide Physical Therapist Practice. 48(2), pp.123-124. 
3. 
Kane, M., Lau, K. and Crawford, D., 2017. Rehabilitation and Postoperative Management Practices After Osteochondral Allograft Transplants to the 
Distal Femur: A Report From the Metrics of Osteochondral Allografts (MOCA) Study Group 2016 Survey. Sports Health: A Multidisciplinary Approach, 
9(6), pp.555-563. 
4. 
Mithoefer, K., Hambly, K., Logerstedt, D., Ricci, M., Silvers, H. and Villa, S., 2012. Current Concepts for Rehabilitation and Return to Sport After Knee 
Articular Cartilage Repair in the Athlete. Journal of Orthopaedic & Sports Physical Therapy, 42(3), pp.254-273. 
5. 
Stark, M., Rao, S., Gleason, B., Jack, R., Tucker, B., Hammoud, S. and Freedman, K., 2021. Rehabilitation and Return-to-Play Criteria After Fresh 
Osteochondral Allograft Transplantation: A Systematic Review. Orthopaedic Journal of Sports Medicine, 9(7), p.232596712110171. 
6. 
Tyler, T. and Lung, J., 2012. Rehabilitation following osteochondral injury to the knee. Current Reviews in Musculoskeletal Medicine, 5(1), pp.72-81. 
7. 
Wang, D., Chang, B., Coxe, F., Pais, M., Wickiewicz, T., Warren, R., Rodeo, S. and Williams, R., 2018. Clinically Meaningful Improvement After 
Treatment of Cartilage Defects of the Knee With Osteochondral Grafts. The American Journal of Sports Medicine, 47(1), pp.71-81. 
 
 
  
