OTA 1999 Posters

Lower Extremity Oblique Osteotomy for Malunion

Steven I. Rabin, MD; William Dobozi, Loyola University Medical Center, Maywood, IL

Purpose: To report the successful use of oblique osteotomy for malunions of the tibia, femur, hip, and fibula.

Methods: A single-cut oblique osteotomy using the technique reported by Sanders et al. (1995) was used to treat 15 patients with lower extremity malunions. Ages ranged from 14 to 81 years of age (average 44). Sites included 10 tibias (5 proximal, 2 midshaft, 3 distal), 4 femur (2 supracondylar and 2 intertrochanteric), and 1 fibula. Two were previous Ilizarov corticotomy sites. Osteotomy was performed at the site of maximal deformity parallel to the plane of minimal deformity as determined by rotating the limb under fluoroscopy. Deformity was corrected by rotating the two bone segments about an axis perpendicular to the cut surfaces. Standard fracture techniques were used for internal fixation of the osteotomy site.

Results: All patients had preoperative pain that was completely relieved in 13 (87%) and decreased in 2 (13%). All patients were satisfied with postoperative cosmesis. The average correction for tibial malunions was 17 degrees in the coronal plane and 15 degrees in the sagittal plane. The average correction for the supracondylar femur malunions was 10 degrees in the coronal plane and 21 degrees in the sagittal plane. The average correction for hip malunions was 31 degrees in the coronal plane. (Accurate sagittal plane measurements could not be obtained with available radiographs.) There were no nonunions, loss of leg length, infections, neurologic injuries, compartment syndromes, or skin sloughs. All osteotomies healed within three months. Two patients had persistent malunion. An 81-year-old female who began with 30 degrees of tibial varus and 40 degrees of procurvatum could only be corrected to 4 degrees of varus and 12 degrees of procurvatum due to tight posterior soft tissues. She walks with a cane without pain. A 31-year-old male with proximal tibial malunion could only be corrected from 35 degrees of anterior angulation to 12 degrees because his leg became pulseless with further correction. He remains on workers compensation and refuses further treatment. The rest of the patients (93%) returned to work or pre-injury activity level.

Discussion: Femoral and tibial fracture malunions cause deformity, which can lead to painful disability secondary to gait abnormalities, early knee or ankle arthritis, and limitations of motion. Patients may dislike cosmetic deformity, and special shoes or orthotics may be needed to correct apparent leg-length discrepancy and abnormal foot positions when walking. Surgical correction by standard procedures (opening or closing wedge osteotomies, or Ilizarov techniques), have significant disadvantages. Wedge osteotomies do not correct deformity in multiple planes. Closing wedges lead to loss of length while opening wedges have increased risk of nonunion. Ilizarov methods may be complicated by nonunion and pin tract infection, and are difficult for patients to tolerate. Oblique osteotomies; however, correct malalignment in the plane of the deformity without loss of length, with a high union rate without cumbersome external fixation. Reported for use in the tibia in other series, we have found oblique osteotomy equally successful for the femur.

Conclusion: Oblique osteotomy should be considered to correct any major long bone defomity.