OATS or Chondral Allograft- Femoral Condyle

An OATS (Osteochondral Autologous Transplant System) and Chondral Allograftprocedures are thosein which afocal chondral lesion is cleaned and drilled and a plug the same size is then harvested from a non-weight bearing surface and placed into the defect to provide bone and articular cartilage. It is usually used for small to medium chondral lesions (1-4cm) and in a younger population (20-50 years of age) who have clicking, locking, and swelling with an osteochondral defect.

  • Goals
  • Protect healing tissue
  • Control post-operative pain and swelling
  • Improve post-operative range of motion
  • Improve functional strength, stability, and neuromuscular control
  • Rehabilitation Principles (specific to OATS)
  • Based on the 4 biological phases of cartilage healing: Proliferation, Transitional, Remodeling, Maturation
  • As knee flexion increases, compressive loads across the joint surface increase
  • The combination of weight-bearing and knee flexion causes a combination of compression and shear across the joint surface that may be detrimental to the repair.
  • Location of the transplanted tissueis key determinants of progression of rehab after OATS- too vigorous rehab can lead to failure.
  • Limit muscular inhibition and atrophy from effusion.
  • Initiate early activity of quads and hamstrings (isometric, isotonic, resistive) and utilize e-stim and biofeedback.
  • Incorporate comprehensive, lower extremity (hip and calf) muscle stabilization and strengthening activities, as well as core strengthening activities.
  • Address limb confidence issues with progression of unilateral activity.
  • Address limb velocity issues during gait with verbal and tactile cueing.
  • Identify motion complications early and begin low-load, long-duration stretching activity:
  • ROM expectations
  • visit 2 - 0-60
  • week 2 - 90 degrees flexion, full knee extension
  • week 4 - AROM within 10 degrees of involved
  • week 6 - full knee flexion (heel to buttock)
  • Initiate early proprioceptive activity and progress by means of distraction techniques:
  • eyes open to eyes closed
  • stable to unstable
  • bilateral to unilateral
  • Constantly monitor for signs and symptoms of patellofemoral irritation.
  • Encourage low impact cardiovascular activity and patellofemoral protection strategies. (especially those found to have CMP at surgery
  • Clinical Restrictions
  • Heel touch weight bearing for 6 weeks
  • No flexion under weight-bearing beyond 45 degrees for 8 weeks.
  • No flexion under weight-bearing beyond 90 degrees for 12 weeks.
  • Assistive Device Guidelines
  • Post-op brace:
  • Locked at 0 degrees for first 2 weeks except for exercises
  • Sleep in brace locked for 4 weeks. In first 4 weeks patient can be out of brace at night if full extension is achieved.
  • Discontinue brace at 4 weeks.
  • Assistive device (crutch, cane, walker)—modified weight bearing for 4-6 weeks post operatively, FWB at 6 weeks. This is dependant on size of lesion—progress more slowly with larger lesions.
  • Crutch use:
  • 2 crutches/walker for 6 weeks heel touch weight bearing, then progress to 1 crutch to normalize gait.
  • FWB at 6 weeks
  • Dependant on size of lesion. May need to progress more slowly with larger lesions
  • Functional Activity Guidelines
  • Driving:
  • 7-14 days
  • Dependent upon:
  • adequate muscle control for braking and acceleration.
  • Proprioceptive/reflex control.
  • Adequate ROM to get into driver’s side.
  • Confidence level
  • car insurance restrictions on driving after surgery
  • no requirement of pain medication
  • Golf
  • 6months
  • Dependent upon:
  • symptoms (swelling and pain)
  • range of motion
  • quad control
  • proprioceptive/reflex control of limb
  • no limb-velocity asymmetry with gait
  • encourage the following
  • backwards golf
  • putting, chipping, short irons, 50% swing, 75% swing, 100% swing
  • avoid bunkers, uneven surfaces and severe slopes
  • warm up properly with stretching
  • Jogging on treadmill
  • 12 weeks
  • observe and minimize limb velocity asymmetry
  • encourage lower impact activity
  • Cutting and Rotational activity
  • 4-6 months
  • Return to sport
  • 6 months for low impact, non contact
  • 8-12 months for high impact, contact sports
  • Dependent upon:
  • Full ROM
  • good quad control
  • 80% score on hop testing
  • 80% isokinetic score ( when ordered and appropriate)
  • Modalities
  • Electrical Stimulation (VMS, biphasic or Russian):
  • intensity to observed contraction
  • appropriate until symmetrical intensity contraction
  • Proximal, lateral quad and distal, medial quad pad placement
  • Variety of positions: quad set, SLR, multi-angle isometrics, mini squats, step-ups.
  • Premodulated, high-volt., bi-phasic, with ice for pain and swelling as needed.

Rehabilitation

  • Week 1-3
  • Clinical Guidelines:
  • Control post-op swelling and effusion
  • Maintain patellar mobility
  • Restore active and passive ROM in open-chain
  • Inhibit post-op muscle shut down and quad atrophy (e-stim, biofeedback, verbal/tactile cueing)
  • Progress comprehensive lower extremity stretching program in open-chain positions
  • Progress hip, calf and core strengthening activities in open-chain positions.
  • Cue for proper gait with assistive device appropriately
  • No closed chain exercises including bike for 3 weeks
  • Clinical Expectations
  • Full knee extension
  • AROM knee flexion to 90 degrees
  • Fair+ to Good – quad contraction
  • SLR without quad lag
  • Mod to min effusion
  • Ambulating in brace heel touch WB with 2 crutches
  • Week 3-6
  • Clinical Guidelines
  • Initiate closed chain exercises
  • Control post-op swelling and effusion
  • Maintain patellar mobility
  • Restore active and passive ROM in open-chain
  • Inhibit post-op muscle shut down and quad atrophy (e-stim, biofeedback, verbal/tactile cueing)
  • Progress comprehensive lower extremity stretching program in open-chain positions
  • Progress hip, calf and core strengthening activities in open-chain positions.
  • Cue for proper gait with assistive device appropriately
  • Clinical Expectations
  • Full knee extension
  • PROM to 120 degrees or greater
  • Minimal effusion
  • Good – quad control
  • Full patellar mobility
  • Ambulation with 2 crutches heel touch WB
  • Weeks 6-7
  • Clinical Guidelines
  • Control post-op swelling and effusion
  • Restore ROM
  • Inhibit post-op muscle shut down and quad atrophy (e-stim, biofeedback, verbal/tactile cueing)
  • Progress comprehensive lower extremity stretching program
  • Progress bilateral and unilateral, closed-chain activity to improve limb confidence with knee flexion less than 45 degrees
  • Progress bilateral and unilateral, proprioceptive activity and reactive neuromuscular training (RNT)
  • Progress hip, calf and core strengthening activities
  • Cue for proper gait with and without assistive device appropriately.
  • Progress unilateral flexion under weight-bearing activity (ie. step ups) with knee flexion less than 45 degrees.
  • Progress no-impact endurance activity.
  • Clinical Expectations
  • Symmetrical extension, full knee flexion with asymmetry to end feel
  • Visible and strong quad contraction (Good- to Good)
  • Ambulating FWB without deviations
  • Minimal to no effusion
  • Able to stand on involved extremity for 30”
  • Able to perform unilateral squat to 45 degrees symmetrically
  • Weeks 8
  • Clinical guidelines
  • Continue activities from weeks 1-8
  • Initiate bilateral, low-amplitude plyometric activities with emphasis on deliberate, quality movement.
  • Clinical Expectations
  • Symmetrical extension, full, painfree knee flexion (heel to buttock)
  • Visible, strong, but assymetrical quad contraction (Good – to Good)
  • Ambulating without deviation and without limb velocity asymmetry.
  • Able to land but with asymmetry to landing pattern during bilateral, low-amplitude plyometrics.
  • Week 9
  • Clinical Guidelines
  • Continue activities from weeks 1-9
  • Continue bilateral, low-amplitude plyometric activities with emphasis on deliberate, quality, movement.
  • Initiate unilateral, low-amplitude plyometric activities
  • Initiate and progress bilateral, moderate-amplitude plyometric activity (includes jogging)
  • – (moderate amplitude = 0-6 inches high and 25-50% max distance.)
  • Clinical expectations
  • Symmetrical extension, full, painfree knee flexion (heel to buttock)
  • Visible, strong, but assymetrical quad contraction (Good – to Good)
  • Ambulating without deviation and without limb velocity asymmetry.
  • Able to land but with asymmetry to landing pattern during bilateral, low-amplitude and bilateral, moderate-amplitude plyometrics.
  • Week 10
  • Clinical guidelines
  • Continue activities from weeks 1-10
  • Continue bilateral, low-amplitude plyometric activities with emphasis on deliberate, quality movement.
  • Continue unilateral, low amplitude plyometrics
  • Progress bilateral, moderate-amplitude plyometric activity (includes jogging)
  • Initiate unilateral, moderate-amplitude hopping activity
  • – (moderate amplitude = 0-6 inches high and 25-50% of max distance.)
  • Clinical Expectations
  • Symmetrical extension, full, painfree knee flexion (heel to buttock)
  • Visible, strong, but assymetrical quad contraction (Good – to Good)
  • Ambulating without deviation and without limb velocity asymmetry.
  • Able to land but with asymmetry to landing pattern during unilateral, moderate-amplitude hopping
  • Week 11
  • Clinical Guidelines
  • Continue activities from weeks 1-10
  • Continue bilateral and unilateral, low-amplitude hopping
  • Progress unilateral and bilateral, moderate-amplitude hopping (includes jogging)
  • Initiate bilateral, high amplitude hopping
  • –(high amplitude = 6-12 inches high, 50-75% max distance)
  • Progress higher level agility activities (forward, retro and lateral only – no cutting activities). Ladders, cones, lateral shuffling etc.
  • Clinical Expectations
  • Symmetrical extension, full, painfree knee flexion (heel to buttock)
  • Visible, strong, but assymetrical quad contraction (Good – to Good)
  • Ambulating without deviation and without limb velocity asymmetry.
  • Able to land but with asymmetry to landing pattern during unilateral, moderate-amplitude hopping and bilateral, high amplitude hopping.
  • Weeks 12-16
  • Clinical Guidelines
  • Continue activity from weeks 1-12
  • Continue bilateral and unilateral, low-amplitude hopping
  • Continue bilateral and unilateral, moderate amplitude hopping
  • Continue bilateral, high-amplitude hopping
  • Initiate unilateral, high amplitude hopping
  • – (high amplitude = 6-12 inches high, 50-75% max distance)
  • Progress higher level agility activities
  • Initiate sports-specific cutting and agility activity.
  • Clinical expectations
  • Symmetrical extension, full knee flexion (heel to buttock)
  • Visible, strong, symmetrical quad contraction (Good)
  • Ambulating without deviation and without limb velocity asymmetry
  • No effusion
  • Able to demonstrate good landing with all hopping activity
  • Good athletic posture (spine erect and shoulders back)
  • No valgus with landing
  • Soft landing
  • Able to “stick the landing”
  • Demonstrate 80-100% score on single leg hop test.
  • Proper coordination with sport-specific, agility activity.

References

Reinold M., Wilk K., Macrina L., Dugas J., Cain E. Current Concepts in the Rehabilitation Following Articular Cartilage Repair Procedures in the Knee. J Orthop Sports Phys Ther 2006;36(10):774-794.

Wilk K., Briem K., Reinold M., Devine K., Dugas J., Andrews J. Rehabilitation of Articular Lesions in the Athlete’s Knee. J Orthop Sports Phys Ther 2006;(10):815-827.

Bartha L., Vajada A., Duska Z., Rahmeh H., Hangody L. Autologous Osteochondral Mosaicplasty Grafting. J Orthop Sports Phys Ther 2006;(10):739-750.