Knee Operations and Procedures


Rehabilitation: Patella -Trochlea MACI repair


Rehabilitation Guide for Patella and Trochlea MACI Repair

goals Following repair of the patella or the trochlea surfaces there are key differences in the rehabilitation as the involved surfaces take load during bending of the knee and not when standing with leg straight.

First 6 weeks: Graft Protection phase

First 1 -2 days before going home

KNEE EXTENSION SPLINT (BRACE) APPLIED IN THEATRE HOLDING KNEE STRAIGHT until first morning. Then start bending knee on first morning. Leg to stay straight in knee brace when walking and at night.
Full weight bearing as tolerated in knee brace holding knee in extension, using crutches
Exercises taught and rehabilitation program explained, including principle of avoiding load on the bent knee.
Discharge plan made including analgesia, physiotherapy and 6 week Outpatient appointment.

Weeks 1-6

Principle: This phase must allow protection of the graft from the shear forces associated with bending the knee under load. Movement without load is vital to aid nutrition of the joint surfaces.

Full weight bearing is allowed with the hinged knee brace locked in extension. FLEXION TO A SET RANGE IS ALLOWED DEPENDING ON GRAFT SITE. – SEE THE DECLARED SAFE RANGE AT START OF REHAB SECTION.

There must be no load on the patella-femoral articulation during this phase to avoid shearing forces on the new graft. NO OPEN CHAIN EXERCISES

Movement: Free range of movement when sitting building to 120 degrees by 6 weeks

Example Exercises and illustrations
Static quadsstatic quads

  • Tighten the muscle on top of thigh.
  • Push the back of your knee down to bed
  • Hold for 5 seconds. X10 3 times a day.



Straight leg raising with no lag.Straight leg raising with no lag

  • Lie on your back.
  • Keep one knee bent, with foot flat on the floor.
  • Lift operated leg about 30cm while keeping knee straight and toes pointed in the air.
  • Hold for 10 seconds and Repeat 10 times.

Knee flexion/extension - heel on gym ball or sliding on floor or other surface.

Heel slides.heel slides

  • Sit on chair with foot on floor and bend knee. Must be done with minimal friction resistance on the foot - need slippery surface

Static glutei: Tighten buttock muscles and hold for about 5 seconds and then relax. Repeat 10 times

Hamstring and calf stretching when sitting

Control swelling with ice packs (open brace)

Patella mobilisation – to prevent tethering of the patella in scar tissuepatella mobilisation
Sideways: Stand or sit with leg straight, push kneecap outwards, then push towards opposite knee. Repeat 10 times.
Up and down: Push kneecap towards foot, allow to return to position. Repeat 10 times.




Circulation Exercises – Calf PumpingCalf pumping

  • Slowly move your ankles, pulling your toes up towards your head, then point your toes down.
  • Repeat 10 times.

Hip flexion/extension/abduction/adduction with knee in extension.

Exercises Weeks 4-6:

Hamstring stretch in standing.hamstring in standing

  • Stand with leg to be stretched on floor or on stool, pull toes towards you and lean forwards keeping leg straight.
  • Hold for 20 secs. Repeat 3 times each leg.





Calf Stretch in standing (from week 4 only)Calf Stretch

  • Place leg to be stretched behind other leg with feet parallel and back heel flat on floor.
  • Bend front knee until you feel stretch in the back of your calf.
  • Hold for 20 secs. Repeat 3 times.Rowing machine - no hands or lowest load setting.

Exercise bike – build up to 500 revolutions x3 daily (must have 1000 flexion to achieve this).

Hydrotherapy/swimming - no breaststroke until week eight.

Weeks 7-12 Transition and Loading phase

During this phase the aim is to regain full flexion and start strength work without bringing on swelling or putting shear forces on the graft. The swelling determines progress of exercises. Ice after exercise may of physio

The brace is removed and normal walking is allowed BUT no excessive load on the patella-femoral surfaces until 3 months

  • Wt bearing: Full weight bearing without crutches
  • Range of movement: Build to full flexion and maintain full extension
  • Strength exercises: closed chain strength work introducing open chain not before 12 weeks
  • Functional activities: Driving – when safe bend and control at around 8 weeks

Example exercises

  • Functional closed chain activity are allowed including low step ups 0 - 30º of knee bend
  • Progress proprioception:-
  • Trampette double leg / single leg stand
  • Wobble board
  • Treadmill slow walk
  • ↑ Static Ex Bike / Ordinary Bike
  • Knee Ext 0 - 30º in standing with resistance of T/Band

Month 4 - 6 Maturation phase

Increasing strength work and starting functional exercises without bringing on swelling. The graft can begin to tolerate some shear forces from open chain

During this phase increased load on the articulating surfaces is allowed but the intention remains to keep load off the patella-femoral surfaces for as long as possible.

Therefore the sequence is a gradual increase in functional training with the mainstay being cycling with gradually increasing load.

  • Wall slides are to be avoided
  • Activities that increase swelling are to be avoided
  • Treadmill fast walk – supervised only
  • Stepper / Cross trainer
  • ↑ Walking distance
  • Circuit training
  • No progression to jogging until 6 months
  • Cycling, rowing and cross-trainer but no jumping.
  • Continue strength training as effusion resolves

6 Months Onwards: Return to functional activities

The graft is now firm – but not fully mature. There may still be some sensation of grating and again swelling is used as the guide to progress. Avoid generating swelling and pain. Gradual progression and aim to begin sports specific training when agreed with consultant/ physiotherapist.
knee rehab

  • Gentle jog, then gentle change of direction single leg hurdle/step over under supervision.
  • Acceleration/Deceleration up to 50% speed.
  • Plyometrics.
  • Skipping and hopping.
  • Star jumps (from 8 months).
  • Acceleration/Deceleration runs ¾ speed (from 8 months).
  • Figure of 8 runs forwards/backwards.
  • Slalom forwards/ backwards.
  • Run–sit–run then gradually introduce cutting/sudden stop.
  • Increasing running distance and progress to sprints 10m-20m-50m.

After 12 months an MRI scan or second look arthroscopy may be performed. If the grafted area is looking good with filling in of the damaged area and good bonding with the surrounding articular cartilage then return to contact sports is allowed.

Exercises are then tailored to the sport and regaining the required skills and endurance. In addition confidence building and retraining to avoid re-injury is required

Not everyone goes back to their previous level of sport and many choose to conserve the newly repaired knee, knowing that the real goal is a long lasting knee.
















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