# 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

## TL;DR

This study compares two surgical implants for lower cervical spine fractures and finds that the n-HA/PA66 cage performs better than titanium mesh over an 8-year period.

## Contribution

The study provides the first long-term evaluation of n-HA/PA66 cages in treating lower cervical spine fractures.

## Key findings

- The n-HA/PA66 cage showed significantly lower cage subsidence compared to titanium mesh cages.
- Both groups had high fusion rates, with no significant difference in clinical outcomes like JOA and VAS scores.
- n-HA/PA66 cages may be superior for anterior cervical construction within 8 years post-surgery.

## Abstract

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.

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.

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).

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.

To compare the long‐term clinical and radiographic outcomes of the TMC and the n‐HA/PA66 cage for anterior cervical corpectomy and fusion in the treatment of lower cervical spine fractures and dislocations. The n‐HA/PA66 cage may be superior to TMC in anterior cervical construction within 8 years after the operation.