Reinforcement of lumbosacral instrumentation using S1–pedicle screws combined with S2–alar screws

Abstract

Retrospective review of 80 patients undergoing S2-ala screw fixation. Main diagnosis was degenerative lumbar instability, adult scoliosis, high-grade listhesis, and nonidiopathic scoliosis. In 66% of patients, the instrumentation using S2-ala screws was part of a major lumbosacral revision surgery. Follow-up averaged 26 months. There were no deaths or major neurovascular complications. First time fusion rate at L5-S1 was greater than 90%. Eight patients (10%) experienced a complication which could be related to the S2-ala screws. Out of 160 S2-ala screws, 16 screws were judged to cause focal irritation and were removed, indicating a survival rate of 90% for the S2-ala screw.

Factors influencing radiographic and clinical outcomes in adult scoliosis surgery: a study of 448 European patients

“…The main causes of reoperation were non-union, ASD and PJK. Patients with non-union are more likely to undergo reoperation and these patients have poorer clinical outcomes compared to patients without reoperation [10,38,39] [19].…”

Biomechanical Comparison of Sacral Fixation Characteristics of Standard S1-Pedicle Screw Fixation versus a Novel Constrained S1-Dual-Screw Anchorage in the S1-Pedicle and S1-Alar Bone

“…If coupled with cross-links and rods rigidly attached to the screws, a constrained tripod anchor-type socket is established at the sacrum. 6 Reproducible clinical results with fusion rates greater than 90% in patients with need for advanced construct strength at L5-S1 were shown. 16 Drawbacks included that rod instrumentation and dissection has to be taken down to the S2 level.…”

“…6 Previously tested sacral-only instrumentation techniques include monocortical and bicortical S1-pedicle screws, with the latter revealing significantly higher pullout resistance. 14 The same is true for pedicle screws with a distal expansion mechanism if compared to standard pedicle screws.…”

“…[1][2][3][4][5] Accordingly, advanced lumbosacral and lumbopelvic fixation is increasingly selected to improve construct stability. 6 This is achieved by incorporating bicortically placed S2-ala screws in sacral constructs, as well as S2-ala iliac or iliac screws, each providing a better mechanical environment for fusion.…”

Beckenringinstabilitäten

“…Sind diese stark disloziert und bestehen zusätzlich neurologische Störungen, ist eine offene Reposition mit Dekompression der nervalen Strukturen und gleichzeitiger Stabilisierung im Sinne von direkten Osteosyntheseverfahren mit lokalen Platten-oder Überbrückungs-osteosynthesen angezeigt [20]. Bei hochinstabilen ein-oder zweiseitigen Sakrumfrakturen oder bei Sakrumausrissfrakturen ergibt sich die Indikation zur spinopelvinen Stabilisierung [12,20,22]. Bei den Typ-C-Verletzungen ist nach Abschluss der operativen Maßnahme am hinteren Beckenring eine zusätzliche Stabilisierung des vorderen Beckenrings angezeigt.…”