Pelvis weight‐bearing ability after minimally invasive stabilizations for periacetabular lesion

Abstract

Periacetabular metastatic lesions cause debilitating weight-bearing pain and pose a risk of pelvic pathologic fracture. Minimally invasive percutaneous stabilization is an alternative palliative therapy over extensive open reconstructive surgeries. This study aimed to investigate the biomechanical behaviors of three distinct techniques of percutaneous periacetabular stabilization. A total of 20 composite hemipelves custom-made to contain Harrington type III periacetabular lesion based on a patient's computed tomograpy scans were assigned to treatment groups of cementoplasty alone using polymethyl methacrylate (Cement), screw fixation alone using ischial and posterior-to-anterior screws (Screws), cement-augmented screws (Screws&Cement), and a control group (Untreated). All hemipelves were loaded in a mechanical test configuration mimicking a single-legged stance, and failure load, failure deformation, and construct stiffness were determined. In the experiments, Screws&Cement demonstrated the highest yield strength (4711 ± 362 N) and was 12% higher than Cement (4005 ± 304 N, p = 0.019), 125% higher than Screws (2097 ± 359 N, p < 0.0001), and 184% higher than Untreated (1658 ± 254 N, p < 0.0001). No significant difference in yield strength was found between Screws and Untreated. Screws&Cement also demonstrated the highest stiffness (1013 ± 92 N/mm), followed by Cement (893 ± 49 N/mm), and both groups were significantly stiffer than Screws (543 ± 114 N/mm, p < 0.0001) and Untreated (580 ± 91 N/mm, p < 0.0001 for Screws&Cement, and p = 0.0003 for Cement).This study demonstrated that a cement-augmented periacetabular reconstruction is an effective option for percutaneous treatment of Harrington III periacetabular metastatic lesion. The addition of pelvic screws over cementoplasty significantly improved the pelvis load-bearing strength. When large periacetabular lesions are present, augmented screw fixation appears to be the superior choice of treatment.

Reinforced cementoplasty for pelvic tumour lesions and pelvic traumatic fractures: preliminary experience

“…When undergoing interventional procedures of the pelvic bone, one must be aware of the biomechanical properties of this complex osseous structure. It is of great importance to identify situations where cementoplasty alone can be sufficient from situations where additional osteosynthesis must be associated to provide the best needed stability [20]. Biomechanical studies of the pelvic bone have shown that the sacral promontory and the peri-acetabular region are the most constrained portions of the pelvis.…”

Emerging Minimally Invasive Percutaneous Procedures for Periacetabular Osteolytic Metastases

“…Biomechanical studies have compared various means of fixation, including cement-only fixation, screw-only fixation, and screw fixation with the addition of bone cement 10,11 . The construct stiffness and yield to failure were highest with the cement-and-screw combination group, followed by the cement-only fixation group and then the screw-only fixation group.…”

Minimally invasive stabilization of pelvic metastatic bone disease: A review of an emerging technique

“…In general, implants are positioned to bridge osteolytic defects and pathologic fractures while originating and terminating in stable bone. When screw fixation is employed, percutaneously injected cement can be performed through the cannulated screws to reinforce the screw landing site, enhancing the strength of the overall construct 28,29 …”

“…25,27 Fixation constructs combining screws and cement have been shown to be more stable than those comprised of cement or screws alone. 28,29 A patient series using photodynamic balloons for fixation has shown functional improvement from surgical intervention; however, this fixation modality has yet to be compared to screws and cement. 14…”

“…Percutaneous ablation results in tissue dehydration and cavitation of neoplastic tissue, which facilitates cavity creation and improves the predictability of cement instillation. Cavity creation is advantageous before cement injection, as it allows for greater cementation of the osteolytic defects, likely conferring greater stability to the overall construct 28 . Regardless of the modality selected, MBD ablation is a valuable tool that we routinely employ during percutaneous stabilization procedures.…”