Contributions of Pubic Rami Fracture Morphology and Fixation to Pelvic Ring Stability in Type 1 Lateral Compression Injuries: A Biomechanical Cadaveric Study

Abstract

Background: Treatment of lateral compression type 1 (LC-1) injuries has historically been nonoperative with immediate weightbearing. However, management of these injuries remains controversial, with reports of displacement at follow-up for nonoperatively managed LC-1 fractures. The goal of our study was to determine the effect of superior pubic ramus fracture morphology and fixation construct on pelvic stability.Methods: Ten fresh-frozen cadaveric were transected into hemipelvises. Incomplete Denis type 1 sacral fractures were made. Hemi-pelvises were randomized to receive a transverse-type or oblique-type superior pubic ramus fracture with the contralateral hemi-pelvis receiving the opposing morphology. A lateral load to 135N was applied with an Instron materials testing machine and lateral displacement of the hemi-pelvis was recorded. Deflection and stiffness were calculated. Statistical analysis was conducted using a t test assuming unequal variances with an alpha = 0.05.Results: Oblique-type superior pubic ramus fractures allowed more deflection compared with transverse-type fractures in the absence of fixation (P = 0.018). The posterior-only and combined anterior and posterior fixation configurations on average reduced deflection more than no fixation or anterior fixation only. In all fixation configuration cases, the average deflection for transverse-type fractures was less than that of the oblique-type fractures.Conclusions: Our findings suggest that displacement of LC-1 pelvic injuries may be related to pubic rami fracture morphology. When looking at initial injury imaging, oblique-type pubic rami fractures may suggest an increased potential for displacement over time. In such cases, we recommend an examination under anesthesia to evaluate for underlying instability and consideration for fixation.

Surgical Versus Non-surgical Treatment of Unstable Lateral Compression Type I (LC1) Injuries of the Pelvis With Complete Sacral Fractures in Non-fragility Fracture Patients: A Systematic Review

“…Currently, there are conflicting views on what constitutes an unstable LC1 injury, with some authors basing their criteria on the degree of fracture displacement [ 22 ] and others on the patient’s pain, for example [ 12 ]. A recent cadaveric study also revealed that the displacement of LC1 injuries may be related to pubic rami fracture morphology with oblique pubic rami fractures being most susceptible to displacement over time [ 23 ].…”

Hidden blood loss and the influential factors after minimally invasive treatment of posterior pelvic ring injury with sacroiliac screw

“…The treatment had been a headache for clinical orthopedics doctors [ 1 ]. The posterior pelvic ring beard 70% of the load of the whole pelvic ring, Posterior pelvic ring injuries such as sacroiliac joint dislocation and sacral fracture were often accompanied by vertical instability and rotational instability [ 2 ]. Therefore, early effective reduction and fixation is very necessary.…”

Operative Management of Stress-Positive Minimally Displaced Lateral Compression Type 1 (LC1) Pelvic Ring Injuries: Analysis of Outcomes Before and After Implementation of a Departmental Stress Protocol

“…2,7–19 To better identify patients who may benefit from surgical fixation, many studies have investigated injury patterns and characteristics suggestive of instability. 2,10,20–23 In addition, examination under anesthesia (EUA) and stress radiographs have been used in evaluation of patients with minimally displaced injuries to determine the degree of dynamic displacement present to identify patients who may benefit from operative management. 5,6,12,18,24–29…”

“…2,[7][8][9][10][11][12][13][14][15][16][17][18][19] To better identify patients who may benefit from surgical fixation, many studies have investigated injury patterns and characteristics suggestive of instability. 2,10,[20][21][22][23] In addition, examination under anesthesia (EUA) and stress radiographs have been used in evaluation of patients with minimally displaced injuries to determine the degree of dynamic displacement present to identify patients who may benefit from operative management. 5,6,12,18,[24][25][26][27][28][29] With the reported advantages of reduced resource utilization, normalized force application, and standardized measurements, lateral stress radiographs (LSRs) have been routinely applied for the evaluation of minimally displaced LC1 injuries at our level 1 trauma center to guide management recommendations.…”