Session VI - Reconstruction

Correction of Complex Post-Traumatic Periarticular Tibial Deformities with Bone Deficit Utilizing the Ilizarov Technique

Lisa K. Cannada, MD; John K. Sontich, MD, Metro Health Medical Center, Cleveland, Ohio

Purpose: Periarticular post-traumatic deformities are among the most challenging limb salvage problems that confront the orthopaedic traumatologist. Traditional methods, such as the use of an intramedullary nail, are not ideal because of the close proximity to the joint. Open plating is additional surgical trauma to an already compromised soft tissue envelope, may offer less than ideal stability in periarticular bone, is not well tolerated in an infected bed and does not allow for the creation of bone stock or restoration of limb length. Our series reviews the treatment of complex periarticular nonunions and malunions with bone loss using the Ilizarov technique, both with and without pre-existing infection, to determine the clinical, radiographic and functional outcome. This technique offers minimal soft tissue dissection with gradual correction of deformity and can deal effectively with osteomyelitis and bone loss.

Methods: Between 1993 and 1998, twenty patients with twenty one periarticular tibial (knee and ankle) deformities were treated by wire ring fixators in combination with distraction osteogenesis for bone loss in a Level one trauma center by a single traumatologist. The original fractures were classified according to the OTA classification and consisted of 6 proximal tibia fractures (OTA 41B and C types) and 15 distal tibia fractures (43A and C types). There were twelve open fractures (one Type II, two IIIa and nine IIIB). There were 7 infected nonunions, 5 sterile non-unions and 9 malunions. All deformities were within 4 cm. of the knee or ankle joint. The average bone loss was 3.5 cm. The mean oblique plane deformity was calculated graphically from AP and lateral x-rays and found to be 23 degrees. Seven patients had translational deformities and 12 patients had evidence of mild post-traumatic arthritis in the adjacent joint. The patients had an average of 4 surgical procedures prior to initiation of the Ilizarov technique.

All patients had corticotomies and distraction osteogenesis. Twelve of the patients had the angular deformity corrected at the original site of injury, with corticotomies performed at a site distant from the original trauma. This was in cases with excessive bone loss or infection, when length correction was not feasible in the traumatized tissue. The remaining eight patients had corticotomies at the original injury site to correct both angulation and length.

Clinical follow-up consisting of history, physical examination and radiographs were obtained on all patients. Functional outcome was assessed by the SF-36 health survey and an Ankle Foot Score (for distal tibia fractures) or a modified Hospital for Special Surgery knee score (for proximal tibia fractures).

Results: There were 13 males and 7 females with an average age of 44 years (range, 21-75). Four patients had diabetes mellitus. The mean time to follow-up was 27.7 months. The external fixator was maintained an average of 226 days (range 99-423 days). Cancellous iliac crest bone grafting was used for 9 patients. Weight bearing was encouraged 2 weeks postoperatively. Distraction osteogenesis commenced at 1 week and proceeded at 0.5 to 1.0 mm per day. Seventeen out of 20 patients achieved union and deformity correction in an average of 204 days. Two patients required additional surgical procedures after the frame was removed, but eventually achieved union and correction. One patient, who had deformity correction over a rod, developed recurrent osteomyelitis and nonunion, resulting in a below-knee amputation. Our mean angular deformity correction was 16 degrees (from 23 to 7 degrees). All translational deformities were corrected. The patients all healed within 1 cm. of their contralateral tibial length. Six out of seven patients with infected nonunions (2 with diabetes) healed with resolution of the osteomyelitis.

The average SF-36 score was 96. Functional outcome as assessed by the Ankle Foot Score was an average of 72 points for the distal tibia periarticular injuries. Patients with proximal tibial periarticular injuries had an average modified HSS knee score of 82, indicating a good result.

Complications included 3 major (1 nonunion, 1 malunion, 1 recurrent osteomyelitis) and 7 minor. Our minor complications included unplanned adjustment of the fixator in 4 patients, delayed regenerate healing requiring bone graft in 1 patient, preconsolidation requiring repeat corticotomy in 1 patient, and a late pin tract infection (3 months after fixator removal) requiring local debridement in 1 patient. There were no major soft tissue complications during treatment.

Discussion & Conclusion: Previous studies have examined the use of the Ilizarov technique for treatment of diaphyseal nonunions and malunions. However, to the best of our knowledge, no study has examined the use of the Ilizarov technique for the correction of post-traumatic periarticular deformities with bone loss. In particular, this deformity is problematic because of the close proximity to the joint and is often accompanied by poor soft tissue coverage, joint contracture, infection and bone loss. Our study suggest periarticular post-traumatic deformities with significant bone loss (average 3.5 cm.) can be adequately addressed by the Ilizarov technique with minimal complications. We had an average of 0.5 complications per patient. This held true in our four diabetic patients as well. The Ilizarov technique allows for simultaneous correction of angular, translational and length deformities. Rotational deformities were not found to be significant in periarticular deformities. Functional scores suggest acceptable outcomes considering the severity of the corrected deformity. We do not recommend length correction over a rod in the setting of a known or suspected septic deformity due to the risk of recurrent infection. Post-traumatic arthritis in the adjacent joint did not progress in our twenty-seven-month period, although an extended follow-up will be needed to evaluate the long-term effects of joint wear.

Our data support the use of the Ilizarov technique as a limb salvage procedure for posttraumatic periarticular deformities with bone loss with or without infection in which the alternative treatment consists of amputation or severe shortening.