Four-year results of a prospective single-arm study on 200 semi-constrained total cervical disc prostheses: clinical and radiographic outcome.
OBJECTIVE Recent studies have described encouraging outcomes after cervical total disc replacement (cTDR), but there are also critical debates regarding the long-term effects of heterotopic ossification (HO) and the prevalence of adjacent-level degeneration. The aim in this paper was to provide 4-year clinical and radiographic outcome results on the activ C disc prosthesis. METHODS A total of 200 subjects underwent single-level activ C (Aesculap AG) implantation between C-3 and C-7 for the treatment of symptomatic degenerative disc disease. Clinical and radiographic assessments were performed preoperatively, intraoperatively, at discharge, and again at 6 weeks, 6 months, 1 year, 2 years, and 4 years. Radiographic evaluations were done by an independent core laboratory using a specific software for quantitative motion analysis. RESULTS Neck Disability Index (NDI) and visual analog scale (VAS) score for neck and arm pain decreased significantly from baseline to the 4-year follow-up. The mean improvement for NDI was 20, for VAS severity and frequency of neck pain 26.4 and 28, and for VAS severity and frequency of arm pain 30.7 and 35.1, respectively. The neurological situation improved for the majority of patients (86.4%); 76.1% of cases were asymptomatic. Subsequent surgical interventions were reported in 7% of the cases, including device removals in 3%. In 2.5% a subsidence greater than 3 mm was recorded; 1 of these cases also had a migration greater than 3 mm. No device displacement, expulsion, disassembly, loose or fractured device, osteolysis, or facet joint degeneration at the index level was observed. Segmental lordotic alignment changed from -2.4° preoperatively to -6.2° at 4 years, and postoperative height was maintained during the follow-up. Advanced HO (Grade III and IV) was present in 27.1% of the cases; 82.4% showed segmental mobility. A progression of radiographic adjacent-segment degeneration occurred in 28.2%, but only 4.5% required surgical treatment. CONCLUSIONS The activ C is a safe and effective device for cervical disc replacement confirming the encouraging results after cTDR. Clinical trial registration no.: NCT02492724 ( clinicaltrials.gov ).
Department of Neurosurgery, BG Clinic Bergmannstrost, Halle, Germany.
Hans-Jörg
HJ
Meisel
Neurocentre, Regional Hospital Liberec, Czech Republic.
Lubomír
L
Jurák
Department of Neurosurgery, University of Helsinki, Finland.
Jussi
J
Antinheimo
Neurosurgical Department, Hospital Maz, Zaragoza, Spain.
Ricardo
R
Arregui
Spinal Surgery, Katholisches Klinikum Koblenz, Germany.
Bernhard
B
Bruchmann
Zentrum für Wirbelsäulenchirurgie, Vivantes Auguste-Viktoria-Klinikum, Berlin, Germany.
Mario
M
Čabraja
Neurosurgery, "Regina Elena" National Cancer Institute, Rome, Italy.
Fabrizio
F
Caroli
Abteilung für Wirbelsäulenchirurgie, Sana Kliniken Sommerfeld, Kremmen, Germany.
Stefan
S
Kroppenstedt
Center for Spine Surgery, Motol University Hospital, Prague, Czech Republic.
Jan
J
Kryl
Department of Neurosurgery, University of Helsinki, Finland.
Juha
J
Pohjola
Spinal Surgery, Warrington District General Hospital, Warrington, United Kingdom; and.
Ian
I
Shackleford
Department of Neurosurgery, University of Rostock, Germany; and.
Steffen
S
Sola
Department of Neurosurgery, BG Clinic Bergmannstrost, Halle, Germany.
Peter
P
Stosberg
Center for Spine Surgery, Motol University Hospital, Prague, Czech Republic.
Jan
J
Stulik
Neurosurgery and Spine Surgery, Spine Center Berlin, Germany.
Christian
C
Woiciechowsky
Neurocentre, Regional Hospital Liberec, Czech Republic.
Petr
P
Suchomel
D000328:Adult; D002574:Cervical Vertebrae; D019299:Decompression, Surgical / Q000379:methods; D004185:Disability Evaluation; D017586:Diskectomy / Q000379:methods; D005060:Europe; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D007595:Joint Prosthesis; D008141:Lordosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D008297:Male; D019547:Neck Pain / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D010147:Pain Measurement; D011446:Prospective Studies; D012720:Severity of Illness Index; D012984:Software; D013997:Time Factors; D059145:Total Disc Replacement / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome
ACDF = anterior cervical discectomy and fusion; AE = adverse event; AP = anteroposterior; ASD = adjacent-segment disease; BMI = body mass index; COI = conflict of interest; COR = center of rotation; FJD = facet joint degeneration; HO = heterotopic ossification; NDI = Neck Disability Index; Neck Disability Index; RCT = randomized controlled trial; ROM = range of motion; VAS = visual analog scale; activ C; adjacent-segment degeneration; cTDR = cervical total disc replacement; cervical spine; clinical outcome; degenerative disc disease; heterotopic ossification; long-term results; range of motion; total disc replacement; visual analog scale