RESUMEN
BACKGROUND: Vertebral compression fractures (VCFs) can cause significant pain and functional impairment, and their cumulative effect can lead to progressive morbidity. This single-arm, prospective feasibility trial, conducted at 4 clinical sites, was undertaken to evaluate the clinical outcomes associated with the use of an innovative vertebral augmentation device, the Kiva VCF Treatment System (Benvenue Medical, Santa Clara, California), in the management of symptomatic VCFs associated with osteoporosis. METHODS: Vertebral augmentation treatment was performed for persistent back pain symptoms in 57 patients (mean age, 71.9 ± 10.4 years), including 46 women, with radiologically confirmed VCFs; 36 of these patients (63%) had reached 12 months of follow-up at this data analysis. There were 51 one-level cases, 5 two-level cases, and 1 three-level case, representing 64 treated levels. Back pain severity and condition-specific functional impairment were evaluated with a standard 100-mm visual analog scale and the Oswestry Disability Index (ODI), respectively, before device implantation as well as at 6 weeks, 3 months, and 12 months. RESULTS: Marked clinical improvements were realized in back pain severity and functional impairment through 12 months of follow-up. The mean back pain score on the visual analog scale improved from 79.3 ± 17.2 before treatment to 21.9 ± 21.3, 21.9 ± 24.6, and 23.2 ± 23.3 at 6 weeks, 3 months, and 12 months, respectively. The mean decrease at 12 months was 49.9 ± 30.3 mm, or approximately 66% (P < .0001). Similarly, the mean ODI score improved from 68.1% ± 16.9% before treatment to 27.4% ± 17.2%, 23.8% ± 18.7%, and 23.3% ± 15.5% at 6 weeks, 3 months, and 12 months, respectively, representing a mean change of 39.2 ± 19.6 percentage points, or approximately 63%, at 12 months. Overall clinical success rates based on a 30% improvement in pain severity or greater and maintenance or improvement in the ODI were 91%, 88%, and 89% at 6 weeks, 3 months, and 12 months, respectively. The vertebral augmentation procedure required injection of a mean of 2.2 ± 0.12 mL of cement per vertebral body. There were 5 levels (8%) where cement extravasation was identified radiographically, and none were related to clinical symptoms. CONCLUSIONS: These pilot findings are encouraging, suggesting robust and durable clinical improvement after this novel vertebral augmentation procedure in patients with painful VCFs.
RESUMEN
BACKGROUND: A feasibility trial was conducted to evaluate the initial safety and clinical use of a next-generation artificial cervical disc (M6-C artificial cervical disc; Spinal Kinetics, Sunnyvale, CA) for the treatment of patients with symptomatic degenerative cervical radiculopathy. A standardized battery of validated outcome measures was utilized to assess condition-specific functional impairment, pain severity, and quality of life. METHODS: Thirty-six consecutive patients were implanted with the M6-C disc and complete clinical and radiographic outcomes for 25 patients (mean age, 44.5 ± 10.1 years) with radiographically-confirmed cervical disc disease and symptomatic radiculopathy unresponsive to conservative medical management are included in this report. All patients had disc-osteophyte complex causing neural compression and were treated with discectomy and artificial cervical disc replacement at either single level (n = 12) or 2-levels (n = 13). Functional impairment was evaluated using the Neck Disability Index (NDI). Evaluation of arm and neck pain severity utilized a standard 11-point numeric scale, and health-related quality of life was evaluated with the SF-36 Health Survey. Quantitative radiographic assessments of intervertebral motion were performed using specialized motion analysis software, QMA (Quantitative Motion Analysis; Medical Metrics, Houston, TX). All outcome measures were evaluated pre-treatment and at 6 weeks, 3, 6, 12, and 24 months. RESULTS: The mean NDI score improved from 51.6 ± 11.3% pre-treatment to 27.9 ± 16.9% at 24 months, representing an approximate 46% improvement (P <.0001). The mean arm pain score improved from 6.9 ± 2.5 pre-treatment to 3.9 ± 3.1 at 24 months (43%, P =.0006). The mean neck pain score improved from 7.8 ± 2.0 pre-treatment to 3.8 ± 3.0 at 24 months (51%, P <.0001). The mean PCS score of the SF-36 improved from 34.8 ± 7.8 pre-treatment to 43.8 ± 9.3 by 24 months (26%, P =.0006). Subgroup analyses found that patients treated at single level and those with a shorter duration of symptoms showed better functional results. By 24 months, the mean range of motion (ROM) value at the treated level had returned to approximately pretreatment levels (12.2° vs 11.1°). There were no serious device-related adverse events, surgical re-interventions or radiographic evidence of heterotopic ossification, device migration, or expulsion in this study group. CONCLUSIONS: These findings indicate substantial clinical improvement for all function, pain, and quality of life outcomes in addition to maintenance of ROM and increase in disc height at the treated level(s). The findings also exhibit an acceptable safety profile, as indicated by the absence of serious adverse events and reoperations following arthroplasty with a next-generation artificial cervical disc replacement device.