Published online May 18, 2019. doi: 10.5312/wjo.v10.i5.219
Peer-review started: January 22, 2019
First decision: April 11, 2019
Revised: April 30, 2019
Accepted: May 14, 2019
Article in press: May 14, 2019
Published online: May 18, 2019
The purpose of open reduction and internal fixation of acetabulum posterior wall fractures is to restore anatomical structure and stability of the hip joint, in order to start weight bearing as soon as possible and prevent hip arthrosis; restoration of the anatomy should preserve function of the joint as well.
Although “special shaped precontoured plates” have been developed in recent years for surgical treatment of this region, studies comparing the traditional plates with the newly designed precontoured plates are lacking.
The main objective of this study was to evaluate the biomechanical properties of precontoured anatomic buttress and conventional curved reconstruction plates (CCRPs) for posterior wall acetabulum fracture treatment, particularly to determine if one provides more stable fixation.
Hemipelvis models (experimental; divided at the sagittal plane and passing over the center of gravity) with similar posterior wall acetabular fractures were fixed with a 5-hole CCRP (right pelvis model) or a precontoured anatomic buttress plate (left pelvis model). These fixated hemipelvis samples were subjected to static load testing (constant testing velocity of 2 mm/min, applied until the load reached 2.3 kN or the acetabular fixation failed) and dynamic testing (sinusoidal wave load, with a maximal load of 2.3 kN and a load ratio of 0.1).
Rigidity of the precontoured anatomic acetabulum buttress plates was significantly higher than that of the CCRPs (P = 0.022).
The findings of this study support the use of anatomic buttress plates for posterior acetabular wall fractures’ surgical treatment. In this surgical treatment, the CCRP is insufficient for safe stability because of its need for anatomic adaptation, lower screw number allowance, and lack of a buttress effect. The precontoured anatomic acetabulum buttress plate is safer, according to its matching the anatomy of the posterior acetabular region and ability to use more screws. In practice, surgeons usually use two reconstruction plates to achieve stable fixation, doubling the surgical time; the use of a single precontoured anatomic acetabulum buttress plate will lessen the surgical time.
For posterior acetabular wall fractures, only fixing the fragment may not always be the best solution. Because the pelvic girdle is exposed to substantial force, according to its anatomic location, stable fixation with multiple screws is needed. Future research efforts must be made from the perspective of clinical practice, to provide biomechanical data from real-life experiences. We also caution that, in clinical practice, this type of fracture does not usually occur in isolation, and is generally accompanied by fracture in other parts of the pelvic girdle (i.e., sacroiliac), and for best results each single fracture pattern must be considered.