Plating of rib fractures in flail chest injury requires intra-operative contouring of generic plates, which can be difficult and time-consuming. This study implemented biometric parameters to derive anatomically contoured rib plates. These plates were tested on ribs to quantify plate fit and to extract a best-fit plating configuration.
Based on a biometric analysis of the surface of ribs, three left and three right rib plates were designed which varied in anatomical in-plane curvature and twist direction. Prototypes of these anatomic rib plates were evaluated on 109 human cadaveric ribs to determine the plate design with the best fit for each rib level. A best-fit plate configuration was defined for each rib level by extracting the plate design that traced the rib surface over the longest plate span. Furthermore, the congruency between the plate and the rib surface was assessed by comparing the characteristic twist of the rib surface to the constant twist of anatomic rib plates.
The best-fit plate configuration with anatomical in-plane curvature traced the ribs over plate spans ranging from 12.5 ± 3.8 cm to 14.7 ± 2.8 cm. Compared to a rib plate without in-plane curvature, anatomical plates of the best-fit configuration significantly increased the plate span by 79% for rib 3 (p < 0.001), by 67% for rib 4 (p < 0.001), and by 65% for rib 9 (p < 0.001). The average twist of the rib surface over 8 cm, 12cm, and 16 cm segments was 8.3° ± 13.2°, 20.6° ± 11.0°, and 32.7° ± 10.6°, respectively. Rib plates with anatomical twist reduced the mismatch between the plate and rib surface to 3.7°, 2.6°, and 8.7° for plate spans of 8 cm, 12 cm, and 16 cm, respectively.
Anatomical rib plates improved plate fit of long plates used for spanning of a flail rib segment. A small set of anatomic rib plates can minimize the need for intra-operative plate contouring.
Anatomic rib plates can reduce the time and complexity of flail chest stabilization and facilitate spanning of flail segments with long plates.
Michael Bottlang, Grant monies (from industry related sources) The authors received funding from Synthes CMF (West Chester, PA, USA) for the conduct of the presented research.; Consultant fee, speaker bureau, advisory committee, etc. The authors Bottlang, Madey, and Long receive consulting fees from Synthes CMF.; No Product/Research Disclosure Information