Rib fractures represent the most common bone fracture, occurring in 10–20% of all blunt trauma patients and leading to concomitant injuries of the inner organs in severe cases. The purpose of this study was to identify specific serial rib fracture patterns after blunt chest trauma. 380 serial rib fracture cases were investigated. Fractures were assigned to five different locations within the transverse plane. Rib level, fracture type, and dislocation grades were recorded and related to the cause of accident. In total, 3735 rib fractures were identified (9.8 per patient). 54% of the rib fractures were detected on the left thorax. Rib fracture distribution exhibited a hotspot at rib levels 4 to 7 in the lateral and posterolateral segments. On average, most rib fractures occurred in crush/burying injuries (15.8, n = 13) and pedestrian accidents (12.8, n = 13), least in car/truck accidents (8.9, n = 75). In the car/truck accident group, 47% of all rib fractures were in the lateral segment, in case of frontal collision (n = 24) even 60%. Fall injuries (n = 141) entailed mostly posterolateral rib fractures (35%). In case of falls >3 m (n = 45), 48% more rib fractures were detected on the left thorax. In cardiopulmonary resuscitation related serial rib fractures (n = 33), 70% of all rib fractures were located anterolaterally. Infractions were the most observed fracture type (44%), followed by oblique (25%) and transverse (18%) fractures, while 46% of all rib fractures were dislocated (15% ≥ rib width). Serial rib fractures showed distinct fracture patterns depending on the cause of accident. When developing a serial rib fracture classification system, data regarding patterns, fracture types, dislocation grades, and associated fractures should be included.

Background: Spinal flexibility can vary among spinal sections and single motion segments. The purpose of this work was to provide a comprehensive overview of the range of motion (RoM) and neutral zone (NZ) values of all spinal levels collected during 30 years of in vitro experiments under standardized testing conditions.Methods: RoM and NZ data obtained from in vitro testing of intact human mono‐ and polysegmental specimens with pure moments of 2.5 Nm for the cervical, 5 Nm for the thoracic, and 7.5 Nm for the lumbar spine were collated from the internal database of the authors' institution. Descriptive statistics were performed with median values and median absolute deviations. Outliers were defined as values beyond twofold standard deviation and excluded from evaluation. Normal distribution was verified using the Shapiro–Wilk test.Results: RoM and NZ data of N = 1139 functional spinal units were collected with sample sizes ranging from n = 6 to n = 224 per segmental level. The cervical spine was very flexible in flexion/extension and moderately flexible in lateral bending, while in axial rotation, the motion segment C1‐C2 was as flexible as the subaxial cervical spine combined. The thoracic spine was the least flexible section in flexion/extension but allowed moderate lateral bending and axial rotation. The rib cage had a strong effect on thoracic spinal flexibility, particularly in axial rotation and at the mid‐thoracic spinal levels. The lumbar spine exhibited moderate flexibility in flexion/extension and lateral bending but showed the lowest RoM and NZ in axial rotation.Conclusions: This unique summary of RoM and NZ data, acquired under the same loading conditions in the same spine tester, provides a detailed insight into overall spinal flexibility and will serve as a valid dataset for the validation of in vitro studies and numerical models of the single motion segments of the spine.

Spinal tumors and unstable vertebral body fractures usually require surgical treatment including vertebral body replacement. Regarding primary stability, however, the best possible treatment depends on the spinal region. The purpose of this in vitro study was to evaluate the effects of instrumentation length and approach size on thoracic spinal stability including the entire rib cage. Six fresh frozen human thoracic spine specimens with intact rib cages (C7-L1) were loaded with pure moments of 5 Nm in flexion/extension, lateral bending, and axial rotation, while monitoring the relative motions of all spinal segments using optical motion tracking. The specimens were tested (1) in the intact condition, followed by testing after vertebral body replacement at T6 level using a unilateral approach combined with (2) long instrumentation (T4–T8) and (3) short instrumentation (T5–T7) as well as a bilateral approach combined with (4) long and (5) short instrumentation. Significant increases of the range of motion (p < 0.05) were found in the entire thoracic spine (T1–T12) using the bilateral approach and short instrumentation in primary flexion/extension and in secondary axial rotation during primary lateral bending compared to both conditions with long instrumentation, as well as in secondary lateral bending during primary axial rotation compared to unilateral approach and long instrumentation. Compared to the intact condition, the range of motion was significantly decreased using unilateral approach and long instrumentation in flexion extension and secondary lateral bending during primary axial rotation, as well as using bilateral approach and long instrumentation in lateral bending. On the segmental level, the range of motion was significantly increased at T4–T5 level in lateral bending using unilateral approach and short instrumentation and significantly decreased using bilateral approach and long instrumentation compared to their respective previous conditions. Regardless of the approach type, which did not affect thoracic spinal stability in the present study, short instrumentation overall shows sufficient primary stability in the mid-thoracic spine with intact rib cage, while creating considerably more instability compared to long instrumentation, potentially being of importance regarding long-term implant failure. Moreover, short instrumentation could affect adjacent segment disease due to increased motion at the upper segmental level.