What are the major differences in the rehabilitation of ACL reconstruction using Hamstring tendon and Patella tendon?
"In the early stages of rehabilitation, the programme for the two graft types will differ because of the differences in the nature of fixation that the operations are able to achieve. Because it has two bony fixation points, the Patella tendon graft is relatively more stable during the initial 6-8 weeks post surgery compared to the hamstring graft, which only has a single bony point of fixation. (W hen the Patella tendon graft is 'harvested' by the surgeon he takes the central third of the tendon, including its bony attachment to the knee cap and shin. For this reason the graft is referred to as Bone - Patella Tendon - Bone graft) .
"Because of this, greater care must be taken with hamstring graft patients to avoid pulling out of the graft from its non-osseous fixation point. This essentially means avoiding positions or activities which overly stress the graft, such as uncontrolled knee hyperextension (forced over straightening), valgus stresses (stresses on the inside of the knee, taking the knee into 'knock knee' position) on a flexed knee and unrestrained anterior Tibial translation (forward movement of the shin bone), most commonly from the pull of the quadriceps during open kinetic chain knee extension activities.
Note: Open Kinematic Chain refers to an exercise in which the involved limb is not fixed against a surface. For example, in the upper limb, a bicep curl is an open kinematic chain exercise, whereas a press up is a closed kinematic chain exercise.
"Open kinetic chain hamstring curls would obviously also have potentially deleterious effects on the donor site of Hamstring graft patients. The most frequent source of difference between early stage rehabilitation programmes for the two graft types is due to inter-surgeon variation, with some surgeons opting for 1-2 weeks immobilisation in an extension splint for hamstring grafts and unrestrained motion for Patella tendon.
"The key to rehabilitating either graft type is to establish normal motion at the knee and patellofemoral joint, reduce any swelling and muscle inhibition around the knee and regain normal motion control of the lower limb. Especially important is to control (and minimise) rotary and valgus loads at the knee in the early stage. Then to offer the patient individually tailored neuromuscular retraining programmes specific to the demands of their sport/lifestyle. This doesn't just involve improving strength or static balance, but also dynamic control of the leg in progressively more stressful scenarios which eventual resemble the tasks required for sport."