Percutaneous Injection of Strontium Containing Hydroxyapatiteversus Polymethacrylate Plus Short-Segment Pedicle ScrewFixation for Traumatic A2- and A3/AO-Type Fractures in Adults

Polymethacrylate (PMMA) is commonly used in vertebroplasty and balloon kyphoplasty, but its use has beenassociated with complications. This study tests three hypotheses: (1) whether strontium hydroxyapatite (Sr-HA) is equivalent toPMMA for restoring thoracolumbar vertebral body fractures, (2) whether the incidence of PMMA leakage is similar to that ofSr-HA leakage, and (3) whether Sr-HAis is resorbed and substituted by new vertebral bone.Materials and Methods.Twoage-andsex-matched groups received short percutaneous pedicle screw fixation plus PEEK implant (Kiva, VCF Treatment System, BenvenueMedical, Santa Clara, CA, USA) filled with either Sr-HA (Group A) or PMMA (Group B) after A2- and A3/AO-type thoracolumbarvertebral body fractures. The Visual Analog Scale (VAS) score and imaging parameters, which included segmental kyphosis angle(SKA), vertebral body height ratios (VBHr), spinal canal encroachment (SCE), bone cement leakage, and Sr-HA resorption, werecompared between the two groups.Results. The average follow-up was 28 months. No differences in VAS scores between Groups Aand B were observed at baseline. Baseline back pain in both groups improved significantly three months postoperatively. Anterior,middle, and posterior VBHr did not differ between the two groups at any time point. SKA was improved insignificantly in bothgroups. SCE decreased insignificantly in both groups on 12-month follow-up using computed tomography (CT). PMMA leakagewas observed in one patient, while no Sr-HA paste leakages occurred. Sr-HA resorption and replacement with vertebral bone wereobserved, and no new fractures were observed.Conclusions. As all hypotheses were confirmed, the authors recommend the use ofSr-HA instead of PMMA in traumatic spine fractures, although more patients and longer follow-up will be needed to strengthenthese results. This trial is registered with NCT03431519