Pelvic Fixation Using S2AI and Triangular Titanium Implants (Bedrock Technique)

Pelvic fixation is becoming an increasingly important caudal anchor point for long lumbar constructs, high-grade spondylolisthesis, fixation of sacral fractures, and support for 3-column osteotomies, by adding lumbosacral fixation anterior to the McCord pivot point. Iliac bolts were once common but have become less favorable due to screw head irritation and complications associated with connecting rods. S2-alar-iliac (S2AI) screws have been shown to achieve equivalent anchoring strength of constructs to the pelvis, while being lower profile and in line with the lumbar instrumentation. More recently, surgeons have noted the potential for S2AI screws to toggle and loosen, commonly in the softer sacrum, leading to caudal anchor failure and possible pseudarthrosis. The addition of triangular titanium implants to augment S2AI screws (bedrock technique) is a relatively new adaptation to reduce toggling on the S2AI screw and improve the overall stability of the pelvic fixation. Video 1 shows the placement of an S2AI screw and triangular titanium implant for pelvic fixation. The patient is a 68-year-old woman who presented with flat back syndrome, spinal stenosis, degenerative spondylolisthesis, pseudarthrosis of previously instrumented levels, and bilateral sacroiliitis. She underwent posterior instrumentation and fusion of L1 to S1 with pelvic fixation, open bilateral sacroiliac joint fusion, and multilevel Smith-Peterson osteotomies and transforaminal lumbar interbody fusions.

Arthrodesis Using Bilateral Dual Iliac Screws with Autologous Iliac Bone Transfer for the Treatment of Pyogenic Sacroiliitis

Pyogenic sacroiliitis is a relatively rare condition that often leads to surgical treatment, including debridement and arthrodesis. Here we introduce a new surgical technique using bilateral dual iliac screws to secure early ambulation and maximal fusion success rate for the treatment of pyogenic sacroiliitis. We retrospectively reported a case and technical reports of pyogenic sacroiliitis treated by a new bilateral dual iliac screw fixation arthrodesis technique using radiologic outcomes, including plain X-rays and MRI scans, as well as outcomes based on the visual analogue scale for pain measurement. This technique improved uncontrolled pyogenic sacroiliitis with immediate stability that enabled ambulation and secured firm fixation for extensive evacuation of infected debris and subsequent autograft bone arthrodesis. In conclusion, we recommend bilateral dual iliac screw fixation for the treatment of pyogenic sacroiliitis, as this technique can improve uncontrolled pyogenic sacroiliitis with immediate stability.

[Pelvic bone radionecrosis as a late consequence of short-distance radiation therapy]

The paper deals with the estimation of the capabilities and role of different radiation techniques in the detection of late postradiation therapy local tissue responses that are evident as radionecrosis. To specify the nature of changes, it is necessary to take into account clinicoanamnestic data, results of laboratory and instrumental studies (standard X-ray study, multislice computed tomography, and magnetic resonance imaging) at any examination stage. A set of the studies can provide the means of significantly analyzing the bone structures and soft tissues and the degree of injury and identifying complications.