Clinical Outcomes of N-HA/pa66 and Titanium Mesh in the Treatment of Lower Cervical Spine Fractures and Dislocations During an 8-Year Follow-Up Period

Abstract

Objective: Studies evaluating the long-term outcomes of the nano-hydroxyapatite/polyamide 66 cages (n-HA/PA66) in treating lower cervical spine fractures have not been reported. The objective is to compare the long-term clinical and radiographic outcomes of titanium mesh cage (TMC) and-HA/PA66 for anterior cervical corpectomy and fusion (ACCF) in the treatment of lower cervical spine fractures and dislocations.

Method: This retrospective analysis included 223 patients treated at our hospital between January 2010 and January 2016 who had undergone single-level anterior corpectomy for lower cervical spine fractures and dislocations (with a minimum follow-up of 8 years) using either a TMC (n = 130) or an n-HA/PA66 cage (n = 93). The radiographic parameters, including segmental alignment (SA), cage subsidence, plate-to-disc distance, cervical lordosis (CL), intervertebral height, and fusion status, along with clinical metrics such as Japanese Orthopedic Association (JOA) scores and visual analog scale (VAS) assessments, were systematically analyzed at preoperative, postoperative, and final follow-up intervals for the patients involved in the study. The Chi-Square (χ ²) test for categorical variables and the Student's t-test for numerical data were used to assess differences between the two groups.

Result: The mean follow-up durations for the TMC group and n-HA/PA66 group were9.81 ± 2.21 and 9.43 ± 0.92 years, respectively. Moreover, final fusion rates were not significantly different between the n-HA/PA66 group and the TMC group (97.8% and 96.9%, respectively). The final cage subsidence was significantly lower in the n-HA/PA66 group (1.56 ± 0.88 mm, with 17.6% subsidence of > 3 mm) than in the TMC group (2.70 ± 2.02 mm, with 36.9% subsidence) (p < 0.01). Furthermore, CL, SA, plate-to-disc distance, JOA scores, and VAS scores were not significantly different between the two groups (all p > 0.05).

Conclusion: Within 8 years following single level ACCF surgery, the n-HA/PA66 cage may be better than TMC in anterior cervical construction for treating lower cervical fractures and dislocations.

Keywords: anterior cervical corpectomy and fusion; lower cervical spine fracture and dislocation; nano‐hydroxyapatite/Polyamide66 cage; titanium mesh cage.

FIGURE 1

A 40‐year‐old man who underwent 1‐level corpectomy with a nano‐hydroxyapatite/polyamide66 strut for cervical reconstruction. The preoperative cervical X‐ray (A) (a significant collapse of the C6 vertebra): 1 week postoperatively lateral X‐ray (B) (C6 corpectomy and the n‐ha/pa66 cage used for reconstruction improved CL, SA, and IH). The radiographic films (C) and 3D‐CT (D) scan showing satisfying bony fusion with a little cage subsidence at the 9.5‐year follow‐up.

FIGURE 2

A 43‐year‐old male who underwent 1‐level corpectomy with a titanium mesh cage used for cervical reconstruction. The preoperative cervical X‐ray film (A) (showing a C5 burst fracture): 1 week postoperative lateral X‐ray (B) (C5 corpectomy and the titanium mesh cage used for reconstruction improved CL, SA, and IH). The radiographic films (C) and 3D‐CT (D) scan showing satisfying bony fusion at the 9‐year follow‐up with a little cage subsidence and partial bone resorption. CL, cervical lordosis; IH, intervertebral height; SA, segmental alignment.