unique orthopaedic devices

Jack PCL

Posterior cruciate ligament knee brace

Patents: EP 1 575 464 / EP 1 114 619 / EP 0 841 044 / US 7,309,322 / US 5,954,677


The Jack PCL knee brace is a unique solution for PCL injuries, offering a dynamic anteriorly directed force to hold the leg in a neutral position so preventing any potential for posterior sagging.

The force set through the hinge is individually adjustable to the size and weight of the patient’s leg and is appropriate for both conservative and post-operative treatments.


  • PCL ruptures
  • Partial ruptures and elongations of the PCL


  • Constant translation force independent of flexion angle
  • New! Optimised hinge geometry
  • New! Smaller hinge with proven features:
  • Spring force can be adjusted infinitely and individually
  • Spring force can be easily increased or reduced at any time
  • Spring tension can be switched on and off without tools whilst retaining the set pressure force at the calf shell
  • Limitation in 15° increments in extension and flexion
  • Extension limitation 0° / 15° / 30° / 45°
  • Flexion limitation 60° / 75° / 90° / 105° / 120°
  • ROM possible from 0° to 120°
  • Temporary immobilisation possible
  • New! Optimised shell and strap system:
  • High level of wearing comfort due to breathable, lightweight aluminium thigh shells
  • High flexibility due to adjustable, customisable thigh shells
  • Extended size system, including paediatric sizes
  • Modular elements that can be combined with one another
  • New! Anatomically shaped tibia shell to improve pressure distribution
  • Strap system can be adjusted to suit individual requirements
  • Easy handling and high level of wearing comfort
Jack PCL diagram 1

The Jack PCL Principle

1 The Problem:

Following PCL injuries the strain on the ligament in rehabilitation is high. Often an elongation of the PCL can be observed and leads to chronic knee instability.

2 The Goal:

To avoid an elongation of the PCL the posterior drawer position of the knee must be avoided.

Jack PCL diagram 2

3 The Solution:

The Jack PCL brace helps avoid the posterior drawer position. An anterior directed force on the tibia secures the PCL. The brace is based on a disengagement of rotation and translation so that the tibia is held in the correct position during extension and flexion. The PCL is secured over the entire ROM and functional rehabilitation can take place without risking an instability of the knee.

Mode of operation

The Jack PCL brace overcomes the gravity of the lower leg to relieve the posterior cruciate ligament. The anterior directed translation force ensures that the posterior drawer position is avoided. The translation force may be adjusted to the leg and weight of the patient through setting the tension on both sides of the brace. In this way the detrimental effects of the muscle and gravitational forces can be counteracted.

Advantages of the Jack PCL

Functional Rehabilitation

The Jack PCL allows for functional rehabilitation. Extensive immobilisation of the knee can be avoided and an early return to everyday life is supported.

Controllable Translation Force

The anterior directed translation force on the tibia is independent of the extension and flexion. The tibia is held in the correct position in relation to the femur during the full range of motion. Extensive pressure in flexion and resulting compression of the calf is avoided.

Disengagement of Rotation and Translation

The translation force is independent of the rotation in the knee so that co-axial alignment of the hinges to the knee joint is unnecessary. The brace can therefore be fitted easily, whilst the hinges leave enough space in case of swelling after trauma or surgery.

Treatment of Other Injuries

The controllable translation force can be set to avoid extensive pressure on the tibia, therefore the Jack PCL can be used in case of a combined PCL and ACL injury. Using a bending iron, the long levers of the upper thigh shell can be set in valgus position in case of a posterolateral injury or in varus position in case of an MCL injury.

Wear time

Experience has shown that if the brace is only utilised for two months there is a risk of instability re-occurring, since the collagen is still under re-vascularisation. We therefore recommend that the Jack PCL brace is worn for 3 - 4 months.

It is important to explain to the patient the principles behind the product so that he/she is convinced of the necessity to wear the brace 24 hours a day for the full rehabilitation period. If the patient removes the brace at night, or loosens the straps, the effect will immediately be lost and the graft or isolated tear is then exposed to gravity and most likely stretching.

For a conservative treatment, the Jack PCL brace should be applied within the first three weeks post trauma.

Clinical studies

(can be viewed and downloaded from our website - www.braceorthopaedic.co.uk)

Posterior cruciate ligament tears: functional and postoperative rehabilitation. Casey M Pierce, Luke O'Brien, Laurie Wohlt Griffin and Robert F LaPrade.

Acute isolated injury of the posterior cruciate ligament treated by a dynamic anterior drawer brace. M Jacobi, N Reischl, P Wahl, E Gautier and R P Jacob.

Treatment of isolated PCL tears using the dynamic PCL brace. R P Jakob and Emanuel Gautier.