ACL Revision

Dr. Don Johnson

Director Sports Medicine Clinic Carleton University

Assistant Professor Orthopedics University of Ottawa On, Canada

Causes of Failure of ACL Reconstruction

Incorrect Technique
Incorrect tunnel Placement
Graft fixed in lax position
Synthetics
Failure of Graft Incorporation
Host Factors
Missed Associated Instabilities
Re-Injury

Steps in Planning ACL Revision

Determine the cause of Failure
Choose the appropriate graft
Autograft

Quadriceps tendon
Patellar tendon – same or opposite side
Semi-t opposite side

Allograft

Patellar tendon
Achilles tendon

synthetic
Plan the hardware removal
Plan tunnel placement
Large tunnel

Case Report

BL is a 36 year old who underwent a double bundle semi-t reconstruction in 1994. She noticed increased instability this past year.

The examination demonstrated a positive Lachman, positive pivot shift. The KT-1000 was 17, 19, 21, 22

Approximately a year ago she tore the opposite ACL. She also had complaints of instability of this knee. The KT-1000 was 15, 17, 19, 20.

xray_acl_revision_semi-t.JPG (14713 bytes)

The x-ray of the failed semi-t knee showed mild degenerative changes in the medial compartment. A large tibial tunnel was also noted.

acl_bilat_setup2.JPG (17233 bytes)

The set up for bilateral ACL reconstructions

The graft choice.

The revision side was reconstructed with a 10mm central quads tendon graft. It was felt that the quads tendon, because of it's large cross sectional size was the best choice to fill the large tunnels.]

knee_quads-tendon_endobutton_completed.JPG (20476 bytes)

The arthroscopic appearance of the tunnel enlargement. The tendon has not healed to the tunnel. In the right photo you can see that the tunnel is lined with fibrous tissue.

acl_failure_semi-t_tunnel_enlargment.jpg (12772 bytes)

acl_failure_semi-t_tunnel_enlargement_nohealing.jpg (10783 bytes)

The femoral tunnel was dilated.

acl_dilators_closeup.JPG (21574 bytes)

Studies have shown that if the tunnel is dilated up 2 sizes, the pullout strength is increased by 30%.

The endobutton was used to secure the proximal tendon end in the dilated femoral tunnel. The proximal end of the tendon is also fixated at the tunnel aperture with a bioscrew.

The distal bone block was fixated at the proximal femoral tunnel with a bioscrew and the leader sutures were tied over a button.

The arthroscopic photo below of the completed quads tendon graft shows that it fills the large tibial tunnel, probably better than a patellar tendon graft would.

acl_failure_quads_graft.jpg (14463 bytes)

Complication

When inserting the tibial tunnel bioscrew, the guide wire bent, and it was impossible to advance the screw. The leader sutures on the bone block broke while providing contertraction for the screw. Now what?

The proximal end of the graft is firmly fixed in the femoral tunnel with a screw and endobutton.

An incision was made over the endobutton, the suture cut, the screw removed and the graft pulled out. Sutures were re applied to the graft and the graft re inserted in the same fashion. The distal leader sutures were switched to No 5 Ticron, rather than the No 2 Ticron.