title: Anterior hyperlordotic cages: early experience and radiographic results.
abstract: OBJECTIVE The aim of this study was to evaluate the segmental correction obtained from 20° and 30° hyperlordotic cages (HLCs) used for anterior lumbar interbody fusion in staged anterior and posterior fusion in adults with degenerative spinal pathology and/or spinal deformities. METHODS The authors report a retrospective case series of 69 HLCs in 41 patients with adult degenerative spine disease and/or deformities who underwent staged anterior, followed by posterior, instrumentation and fusion. There were 29 females and 12 males with a mean age of 55 years (range 23-76 years). The average follow-up was 10 months (range 2-28 months). Radiographic measurements of segmental lordosis and standard sagittal parameters were obtained on pre- and postoperative radiographs. Implant subsidence was measured at the final postoperative follow-up. RESULTS For 30° HLCs, the mean segmental lordosis achieved was 29° (range 26°-34°), but in the presence of spondylolisthesis this was reduced to 19° (range 12°-21°) (p < 0.01). For 20° HLCs, the mean segmental lordosis achieved was 19° (range 16°-22°). The overall mean lumbar lordosis increased from 39° to 59° (p < 0.01). The mean sagittal vertical axis (SVA) reduced from 113 mm (range 38-320 mm) to 43 mm (range -13 to 112 mm). Six cages (9%) displayed a loss of segmental lordosis during follow-up. The mean loss of segmental lordosis was 4.5° (range 3°-10°). A total complication rate of 20% with a 4.1% transient neurological complication rate was observed. The mean blood loss per patient was 240 ml (range 50-900 ml). CONCLUSIONS HLCs provide a reliable and stable degree of segmental lordosis correction. A 30° HLC will produce correction of a similar magnitude to a pedicle subtraction osteotomy, but with a lower complication rate and less blood loss.
authors.affiliation: Department of Orthopaedic Surgery, University of Pennsylvania, Pennsylvania Hospital, Philadelphia, Pennsylvania.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Saville
authors.affiliation: Department of Orthopaedic Surgery, University of Pennsylvania, Pennsylvania Hospital, Philadelphia, Pennsylvania.
authors.forename: Abhijeet B
authors.initials: AB
authors.lastname: Kadam
authors.affiliation: Department of Orthopaedic Surgery, University of Pennsylvania, Pennsylvania Hospital, Philadelphia, Pennsylvania.
authors.forename: Harvey E
authors.initials: HE
authors.lastname: Smith
authors.affiliation: Department of Orthopaedic Surgery, University of Pennsylvania, Pennsylvania Hospital, Philadelphia, Pennsylvania.
authors.forename: Vincent
authors.initials: V
authors.lastname: Arlet
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
keywords: ALIF; ALIF = anterior lumbar interbody fusion; ALL = anterior longitudinal ligament; HLC = hyperlordotic cage; PEEK = polyetheretherketone; PLL = posterior longitudinal ligament; PSO = pedicle subtraction osteotomy; SPO = Smith-Petersen osteotomy; SVA = sagittal vertical axis; adult deformity; anterior lumbar interbody fusion; degenerative; hyperlordotic cages; sagittal imbalance; technique