Thursday, 9 September 2010

Knee injury: ACL (Part II)

In follow-up to my previous article on "Knee injury: ACL (Part I)", here is the 2nd half of my discussion to provide an overview of ACL surgery and post-op rehabilitation.

Who will benefit from surgery?
  • Individuals with active lifestyles
  • Individuals involved in high-level sporting activities (eg. soccer, basketball, netball, footy, skiing, etc)
  • Those with recurrent knee instability due to ACL deficiency
  • Those wishing to protect their knee joint and cartilage from future damage
  • Individuals who have attempted and failed conservative management with recurrent knee pain and instability
ACL reconstruction is mainly performed via an arthroscopic procedure. Deciding on what structure to use will depend on several factors including the preference of the surgeon, the individual's age and body, type of sport and whether there are other associated injuries. 

There are commonly three structures that can be used:
1. Hamstring tendon (parts of the tendon is harvested to create a graft)
- Advantages: Less disturbance in harvesting the graft; a much lower incidence of knee pain post-op
- Disadvantage: The stability of this graft has been questioned by some surgeons

2. Patella tendon (central 1/3 of tendon is used, with a piece of bone from patella and tibia also taken)
- Advantages: Allows for bone-to-bone healing; considered the most secure graft type
- Disadvantage: Higher incidence of knee pain post-op, which may persist for years

3. Donor tissue grafts (the patellar tendon of a cadaver is used)
- Advantages: Smaller risk of infection; less pain post-op
- Disadvantages: Longer healing time (as the sterilisation process kills the living cells of the graft); can be less reliable

An example of the surgical procedure using hamstring tendons:
The knee joint is examined via the arthroscope. Meniscal surgery is performed as required and the ruptured ACL stumps are removed. Via a 2cm incision on the anterior tibia, the semitendinosus and gracilis hamstring tendons are harvested at about 20 cm up the medial thigh. The two tendons are doubled over to create a 4-strand graft and sutured together at both ends. The tunnels for the graft are drilled through the tibia and femur, and the graft is pulled into place in an anatomic position. The graft is secured with interference screws in both the femur and tibia. Full range of motion is achieved prior to final tibial fixation. The wounds are then closed. Braces are not used routinely postoperatively and patients may weight bear as tolerated immediately after surgery. For the vast majority of patients this is a day surgery procedure.

Provided below is an overview of an ACL rehabilitation program. It is important that your rehabilitation is performed under the guidance and supervision of a physiotherapist. 
A few notes of caution:
1. Your program may alter slightly depending on the graft used
2. Most protocols recommend NO open-chain exercises for at least 6 months post-op (although some surgeons have accelerated protocols)
3. Most protocols recommend NO resisted hamstring strengthening for at least 6 weeks

Prehabilitation: Prior to surgery
  • Aims: Prepare the knee for surgery
  • Goals: Reduce swelling, regain full range of motion (ROM) and strength
    • Swelling: Apply ice, wear knee support for compression and stability
    • ROM: Simple knee flexion and extension exercises; should be painfree
    • Strengthening: Static quads, quads/hamstrings co-contractions; should be painfree
  • Can continue to walk, swim or cycle for fitness

Phase 1: Acute Recovery (0-2 weeks)
  • Aims: Post-op pain management and wound healing, mobility
  • Goals: Control swelling, regain full knee extension, improve quadriceps strength and hamstring flexibility, wean off crutches and retrain normal gait
    • Swelling: RICE - rest, ice, compression, elevation (as per pre-op)
    • Mobility: Partial weight-bearing --> full weight-bearing as tolerated (with crutches), gait retraining with full extension at heel strike
    • ROM: Active and passive techniques - assisted knee bends, heel slides, knee extension stretch, gentle hamstring stretch
    • Strengthening: Static quads (long-sitting/lying), static hamstrings, quads/hamstrings co-contractions (seated --> weight-bearing), calf raises

Phase 2: Muscle control (2-6 weeks)
  • Aims: Return to normal function and gait
  • Goals: Eliminate swelling, establish good muscular control of the quadriceps and hamstrings, achieve 120 deg knee flexion, full weight bearing, regain normal hamstring length
  • Duration: 2-6 weeks
    • Swelling: If still persisting, continue with ice and compression  
    • Muscular control: Progress co-contractions of quads/hamstrings by increasing reps/duration and advancing positions (eg. semi-squats, shallow lunges, stepping)
    • Can commence use of gym equipment (painfree) such as leg press, stepper, cross-trainer, mini-tramp
    • Strengthening: Can commence low resistance open-chain hamstring exercises (gentle initially), hip flexion/abd/add strengthening can also start
    • Stretching: Continue with hamstring stretches, add stretches to hip flexor, quads, calf, groin)
    • Gait: Increase walking and continue to retrain normal gait patterns

Phase 3: Balance and proprioception (6-12 weeks)
  • Aims: Improve balance and proprioception (sense of joint position)
  • Goals: Full ROM and strength, improve neuromuscular control, balance and proprioception
  • Strengthening:
    • Progress to more dynamic movements (eg. full lunges, step lunges, squats, use therabands or weights for extra resistance), increase resistance/reps, single leg press
    • Hamstrings: Eccentric work can be added, hamstring curls with resistance, leg press, progress in power and speed of contraction
  • Proprioceptive/balance work: Wobble boards, slide boards, lateral stepping, mini-tramp, single leg balance, balancing on beam 
  • Can commence cycling 
  • Can commence jogging in a straight line on flat surface
  • Consider other areas/muscle groups that may be weakened (eg. glutes, ITB, gastrocs/soleus etc)

Phase 4: Sport-Specific Training (3-6 months)
  • Aim: Return to sports-specific training
  • Goals: Introduce more sport specific techniques and exercises, work on agility and proprioception, increase leg strength, improve fitness
    • Strengthening: Progress strength work (eg. add resistance to squats/lunges/steps/leg press/curls, rower, etc)
    • Proprioceptive work: Add hopping, jump and land activities, lateral movements, side-steps
    • Agility work: Running drills including sideways/backwards running, changing directions, cutting, shuffle runs, ball skills, skipping, etc
    • Fitness training: Jogging (gradually increase speed and duration), cycling, swimming
    • Sports-specific drills (eg. basketball - vertical jumps/pivots, soccer - passing/dribbling, tennis - lateral step lunges, forward/backward running, skiing - slide board, lateral stepping/jumping, hopping, etc)
    • Continue with stretching

Phase 5: Return to Sport (6 months +)
  • Aim: Return to sport with confidence
  • Goals: Continue with sports-specific drills increasing agility and speed, increase resistance with strength work, increase complexity with proprioceptive work
    • Depending on protocol, can commence specific open-chain quads exercises and slowly progress as symptoms allow
    • Continue progression of plyometrics and sports-specific drills
    • Return to sports training and team exercises
    • Return to full competitive sports ONLY at the advice of your Surgeon and Physiotherapist (High risk patients for re-injury include those under 21 years of age and those with mildly increase laxity - these individuals do not usually return to full competitive sport until at least 12 months post-op)

For more information or if you would like to be referred to a physiotherapist, please CONTACT us. 

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