Tape suture constructs for instabilities of the pubic symphysis: is the idea of motion preservation a suitable treatment option? A cadaver study

Abstract

Introduction Current gold standard for the treatment of symphyseal disruptions includes anterior plating, almost entirely prohibiting symphyseal mobility and resulting in an iatrogenic arthrodesis followed by high rates of implant failure. Minimally invasive tape suture constructs have been found to maintain the micro mobility of ligamentous injuries, yet still providing sufficient biomechanical stability. Recently, this technique has been primarily investigated for symphyseal disruptions on synthetic pelvic models. Therefore, the aim of this study was to examine the feasibility of this novel flexible osteosynthesis on cadaveric pelvic models based on the following hypothesis: tape suture constructs ensure sufficient biomechanical stability without inhibiting micro mobility of the pubic symphysis for the treatment of symphyseal disruptions and maintain stability during long-term loading. Materials and methods 9 cadaveric anterior pelvic rings were used in this study and a symphyseal disruption was created in every specimen. The specimens were then exposed to short- and long-term vertical and horizontal cyclic loading after treatment with a tape suture construct in criss-cross technique. The mean maximum displacement (mm) during cyclic loading and the corresponding stiffness (N/mm) were measured and compared. Results Regarding both displacement (mm) and corresponding stiffness (N/mm), the tape sutures displayed a significant difference between short- and long-term loading for cranial and caudal vertical loading (p < 0.01) but differences remained non-significant for horizontal loading (p > 0.05). No tape suture suffered from implant failure during long-term loading. Conclusions The tape suture construct displayed sufficient biomechanical stability without exceeding the physiological mobility of 2 mm of the pubic symphysis; however, also maintained the desired micro mobility of the affected joint necessary to prevent an iatrogenic arthrodesis. Further, all tape sutures maintained stability throughout long-term loading.

Motion preservation for open book injuries of the pubic symphysis –a biomechanical cadaver study

“…In detail, dislocation with anterior plating displays similar mobility to the native condition, showing the incapacity of the plate osteosynthesis to fully withstand the physiological micro mobility of the pubic symphysis and ultimately favoring implant loosening and failure (Fig. 5 ) [ 20 , 21 , 23 – 25 ]. Incipiently screw loosening was observed in 2 specimens after cyclic loading, further reflecting the conflict of a rigid osteosynthesis method for the treatment of the symphyseal motion segment (Fig.…”

“…Previous studies by Cavalcanti Kußmaul et al also examined the use of a similar TSC in initially synthetic and afterwards in cadaver models with isolated anterior pelvic rings [ 20 , 21 ]. Here, the testing force for biomechanical loading was lower (75 N in each direction) as the isolated anterior pelvic ring contributes to up to 30% to pelvic stability [ 21 , 30 ].…”

“…Previous studies by Cavalcanti Kußmaul et al also examined the use of a similar TSC in initially synthetic and afterwards in cadaver models with isolated anterior pelvic rings [ 20 , 21 ]. Here, the testing force for biomechanical loading was lower (75 N in each direction) as the isolated anterior pelvic ring contributes to up to 30% to pelvic stability [ 21 , 30 ]. However, using an isolated symphysis enables loading in the different motions planes of the symphysis: For tension and vertical shear at the pubic symphysis, the authors found a maximum dislocation of 0.30 ± 0.12 mm and 0.59 ± 0.20 respectively.…”

“…These implants allow micro mobility of weight-bearing joints while maintaining sufficient biomechanical stability and are already established for ankle, rotator cuff and knee injuries [ 17 – 20 ]. This technique has already been proven biomechanically equivalently stable to anterior plating for symphyseal disruptions by Cavalcanti Kußmaul et al for both isolated anterior synthetic and anterior human cadaveric pelvic rings [ 20 , 21 ]. However, there is no data evaluating the biomechanical properties of TSC for the treatment of symphyseal disruptions in an entire human pelvic ring.…”

Tratamiento de la osteítis del pubis: artrodesis con nueva técnica a propósito de dos casos y revisión de la literatura

“…15 A pesar de obtener resultados favorables con nuestra técnica de fijación propuesta, otros autores han explorado alternativas que, aunque probadas en modelos cadavéricos, también parecen abordar la patología en sínfisis púbica con éxito. Un reciente estudio que realizaron Calvalcanti y asociados 16 evaluó un innovador método de osteosíntesis con suturas de cinta para tratar estas alteraciones; demostraron estabilidad biomecánica adecuada sin restricciones en la movilidad fisiológica. Se observaron diferencias significativas en la carga vertical, mientras que la carga horizontal no mostró variaciones notables.…”