A Prospective Study of Clinical and Radiological Outcomes of Zero-Profile Cage Screw Implants for Single-Level Anterior Cervical Discectomy and Fusion: Is Segmental Lordosis Maintained at 2 Years?

STUDY DESIGN: Prospective cohort study. PURPOSE: To study clinicoradiological parameters of zero-profile cage screw used for anterior cervical discectomy and fusion (ACDF). OVERVIEW OF LITERATURE: Radiological parameters of various implants used for ACDF are available, but those for zero-profile cage are sparse. METHODS: Patients with unilateral intractable brachialgia due to single-level cervical disc prolapse between April 1, 2011 and March 31, 2014 were included. Clinical assessment included arm and neck pain using visual analogue score (VAS) and neck disability index (NDI) scores. Radiological assessment included motion segment height, adjacent disc height (upper and lower), segmental and cervical lordosis, implant subsidence, and pseudoarthrosis. Follow-ups were scheduled at 1, 3, 6, 12, and 24 months. RESULTS: Thirty-four patients (26 males, 8 females) aged 30–50 years (mean, 42.2) showed excellent clinical improvement based on VAS scores (7.4–0 for arm and 2.0–0.6 for neck pains). Postoperative disc height improved by 11.33% (p<0.001), but at 2 years, the score deteriorated by 7.03% (p<0.001). Difference in the adjacent segment disc height at 2 years was 0.08% (p=0.8) in upper and 0.16% (p<0.001) in lower disc spaces. Average segmental lordosis achieved was 5.59° (p<0.001) from a preoperative kyphosis of 0.88°; at 2 years, an average loss of 7.05° (p<0.001) occurred, resulting in an average segmental kyphosis of 1.38°. Cervical lordosis improved from 11.59° to 14.88° (p=0.164), and at 2 years, it progressively improved to 22.59° (p<0.001). Three patients showed bone formation and two mild protrusion of the implant at 2 years without pseudoarthrosis/implant failure. CONCLUSIONS: The zero-profile cage screw device provides good fusion and cervical lordosis but is incapable of maintaining the segmental lordosis achieved up to a 2-year follow-up. We also recommend caution when using it in patients with small vertebrae.

Single and Multiple Level One Stage Posterior Hemivertebrectomy and Short Segment Fixation: Experience with 22 Cases and Comparison of Single vs. Multilevel Procedures with Minimum 2-Year Follow-Up

STUDY DESIGN: Data of 22 patients with congenital scoliosis who underwent single stage posterior hemivertebrectomies and short segment fixation with a minimum follow-up of 2 years in our centre were studied retrospectively. PURPOSE: To report the efficacy of posterior hemivertebrectomy in single vs multiple level hemivertebra and compare their results. OVERVIEW OF LITERATURE: Single stage hemivertebrectomy is a standard procedure for single level hemivertebra. Results of multiple level hemivertebrectomies have not been reported. METHODS: Twenty-two patients (9 male and 13 female) with the mean age of 11.2 years (range, 2 years 4 months to 24 years 10 months) and a mean follow up of 32 months (range, 4 to 73 months) were studied retrospectively and their results were compared. RESULTS: Average number of hemivertebrae removed was 1.46 (range, 1 to 3). Mean preoperative and postoperative coronal cob angle was 48.7° (range, 22° to 80°) and 24.2° (range, 7° to 41°), respectively (p<0.001). Mean preoperative and postoperative sagittal cobb angle was 32.1° (range, 7° to 76°) and 13.6° (range, 0° to 23°), respectively (p<0.005). Mean coronal and sagittal cob correction percentage achieved was 50.2% and 51.8% respectively. Mean follow-up was 49 months (range, 30 to 84 months). Mean loss of coronal and sagittal correction at final follow-up was 4% (0% to 13.6%) degrees and 3.5% (0% to 20%), respectively. CONCLUSIONS: Posterior hemivertebrectomy in congenital scoliosis is a safe treatment option for up to 3-level hemivertebrae. Excision of thoracolumbar hemivertebrae results in better correction than thoracic and lumbar hemivertebrae.

Single and Multiple Level One Stage Posterior Hemivertebrectomy and Short Segment Fixation: Experience with 22 Cases and Comparison of Single vs. Multilevel Procedures with Minimum 2-Year Follow-Up

STUDY DESIGN: Data of 22 patients with congenital scoliosis who underwent single stage posterior hemivertebrectomies and short segment fixation with a minimum follow-up of 2 years in our centre were studied retrospectively. PURPOSE: To report the efficacy of posterior hemivertebrectomy in single vs multiple level hemivertebra and compare their results. OVERVIEW OF LITERATURE: Single stage hemivertebrectomy is a standard procedure for single level hemivertebra. Results of multiple level hemivertebrectomies have not been reported. METHODS: Twenty-two patients (9 male and 13 female) with the mean age of 11.2 years (range, 2 years 4 months to 24 years 10 months) and a mean follow up of 32 months (range, 4 to 73 months) were studied retrospectively and their results were compared. RESULTS: Average number of hemivertebrae removed was 1.46 (range, 1 to 3). Mean preoperative and postoperative coronal cob angle was 48.7° (range, 22° to 80°) and 24.2° (range, 7° to 41°), respectively (p<0.001). Mean preoperative and postoperative sagittal cobb angle was 32.1° (range, 7° to 76°) and 13.6° (range, 0° to 23°), respectively (p<0.005). Mean coronal and sagittal cob correction percentage achieved was 50.2% and 51.8% respectively. Mean follow-up was 49 months (range, 30 to 84 months). Mean loss of coronal and sagittal correction at final follow-up was 4% (0% to 13.6%) degrees and 3.5% (0% to 20%), respectively. CONCLUSIONS: Posterior hemivertebrectomy in congenital scoliosis is a safe treatment option for up to 3-level hemivertebrae. Excision of thoracolumbar hemivertebrae results in better correction than thoracic and lumbar hemivertebrae.