Cervical disc arthroplasty combined with two‐level ACDF for the treatment of contiguous three‐level cervical degenerative disc disease: A comparative study

Abstract

To compare the differences among constructs with one‐level cervical disc arthroplasty (CDA) and two‐level anterior cervical discectomy and fusion (ACDF). A retrospective study was conducted involving patients who underwent one‐level CDA and two‐level ACDF between June 2012 and July 2020. According to the different locations of CDA and ACDF, we divided the constructs into three types: type Ⅰa: CDA‐ACDF‐ACDF; type Ⅰb: ACDF‐CDA‐ACDF; type Ⅰc: ACDF‐ACDF‐CDA. The differences of clinical and radiological outcomes were evaluated. Fifty‐three patients were included with 29 in type Ⅰa group, 11 in type Ⅰb group, and 13 in type Ⅰc group. After surgery, all groups showed significant improvement in apanese Orthopedic Association, Neck Disability Index, and Visual Analog Scale scores (p < 0.001). Range of motion (ROM) of the total cervical spine in type Ⅰc group decreased significantly compared with those in type Ⅰa and type Ⅰb groups (p < 0.05). No significant differences in ROM of the arthroplasty segment and the variations in ROM of the superior adjacent segment were observed among the three groups. The fusion rates of the superior ACDF segments were significantly higher at 6 and 12 months postoperatively than those of the inferior ACDF segments (p < 0.05). The clinical outcomes were similar among constructs concerning different locations of CDA and ACDF in three‐level hybrid surgery. ROM of the cervical spine in type Ⅰc group decreased significantly compared with that in type Ⅰa and type Ⅰb groups. The fusion rates of superior ACDF segments were higher at early time points after surgery than those of inferior ACDF segments.

Risk Factors of Nonfusion after Anterior Cervical Decompression and Fusion in the Early Postoperative Period: A Retrospective Study

“…Previous studies reported that the rate of cage nonfusion after ACDF was less than 10% at 1‐year follow‐up 32 . However, in the early period after ACDF (during the first 90 days postoperatively), the fusion rate was much lower (15%–62%) at 3‐month follow‐up 33–36 . Lower fusion rates in the early period would result in higher rates of subsidence, cage displacement, and pseudarthrosis.…”

“…Following radiographic recommendations for evaluating cervical fusion, 39,40 fusion was defined as the presence of continuous bone bridges behind the surgical segments on CT three‐dimensional reconstruction. According to our previous study, ‘fusion’ is defined as the presence of ≤2°or 3°motion and/or ≤2 mm of motion of the interspinous distance on flexion–extension X‐rays 33–36,41 . Further, different implant and surgical procedures, as well as screw length and angle, would result in a different fusion rate 9 …”

“… 32 However, in the early period after ACDF (during the first 90 days postoperatively), the fusion rate was much lower (15%–62%) at 3‐month follow‐up. 33 , 34 , 35 , 36 Lower fusion rates in the early period would result in higher rates of subsidence, cage displacement, and pseudarthrosis. Moreover, the nonfusion in the early period would prolong the use of a neck brace and increase the cost to patients, hospitals, and society.…”

“…According to our previous study, 'fusion' is defined as the presence of ≤2 or 3 motion and/or ≤2 mm of motion of the interspinous distance on flexion-extension X-rays. [33][34][35][36]41 teriparatide administration in the acute postoperative period resulted in significantly greater bone formation and a higher rate of the complete fusion by increasing BGP and CTX over 6 months. 42,43 It indicated that the patients whose surgical segments achieved fusion within 3 months of follow-up have higher bone turnover markers.…”

Current Evidence for Hybrid Constructs

“…Huang et al 46 investigated the outcomes among 3 subtypes of Type 1 HS constructs (Type Ia: CDA-ACDF-ACDF; Type Ib: ACDF-CDA-ACDF; Type Ic: ACDF-ACDF-CDA. All groups showed significant improvement in PROs by 1-year follow-up.…”