Fri., 10/15/10 Knee, Tibia & Pediatrics, Paper #54, 3:30 pm OTA-2010
Sagittal Plane Deformity in Bicondylar Tibial Plateau Fractures
Philipp N. Streubel, MD1; Donald Glasgow, MD2; Ambrose Wong, BS1; David P. Barei, MD2;
William M. Ricci, MD1; Michael J. Gardner, MD1;
1Washington University School of Medicine, St. Louis, Missouri, USA;
2Harborview Medical Center, Seattle, Washington, USA
Purpose: The goal of surgical treatment of bicondylar tibial plateau fractures is anatomical reduction and stable articular and metaphyseal fixation. Sagittal plane deformity of large plateau fragments can be difficult to visualize on lateral fluoroscopic imaging, and may be not be readily apparent on sagittal CT reconstructions if not actively sought. Alterations in the tibial slope, particularly between the tibial plateaus, can lead to contact force aberrations and may affect functional outcome. The hypothesis of this study was that sagittal plane deformity in a large series of bicondylar tibial plateau fractures is highly prevalent and of variable magnitude.
Methods: 195 patients with acute bicondylar tibial plateau fractures (OTA 41C) were identified from prospective databases from two Level 1 trauma centers during a 30-month period. Patients without adequate CT scans, and those with coronal plane fractures or plateau comminution were excluded, leaving 74 patients available for study. 47 (64%) were male, and the average age was 49 years (range, 16-82). Sagittal inclination of the main fragment of both the medial and lateral plateau was measured in relation to the longitudinal tibial axis on CT reconstruction images. Student t tests and χ2 tests were used for statistical comparisons. Interobserver and intraobserver reliability were determined by repeat measures by two independent reviewers.
Results: For the lateral tibial plateau, average sagittal plane angulation was 9.8° apex
anterior (range, 37° apex anterior to 17° apex posterior; SD, 9.8°). In the medial plateau,
average angulation was 4.1° apex anterior (range, 31° apex anterior to 16° apex posterior;
SD, 9.1°). For each patient, the difference in sagittal plane alignment between the medial
and lateral plateaus was 9.0° (range, 0°-31°; SD, 7.1°), which was statistically significant (P
< 0.001). 42 lateral plateaus were angulated more than 5° from the “normal” anatomic slope
(defined as 5° of posterior tibial slope). Of these, 76% were angulated in the apex anterior
direction (ie, increased posterior slope). 43 (58%) of the medial plateaus were angulated
greater than 5° from normal, of which only 47% were apex anterior (P = 0.019 compared
to lateral plateaus). Intraobserver correlation was high for both observers for the medial (r = 0.99 and r = 0.92, P < 0.01) and lateral plateaus (r = 0.90 and r = 0.95, P < 0.01). Similarly,
correlation between observers was high for both medial and lateral measurements (r = 0.96
and r = 0.92, respectively; P < 0.01).
Conclusions: Substantial sagittal plane deformity exists in a majority of bicondylar tibial plateau fractures. The lateral plateau has a higher propensity for sagittal angulation, and tends to be in the apex anterior direction (increased posterior slope). Accurate restoration of anatomic alignment requires identification of this deformity and appropriate specific reduction maneuvers.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.