Introduction: There is an increasing interest in the concept of motion preservation in cervical disc degeneration surgery. There is still a controversy regarding the effect of posterior placement of the disc on the segmental motion of the treated level.

The objective of this study is to assess the effect (if any) of posterior placement of the LP Prestige disc on the motion.

To our knowledge this is the first study to assess the relation of posterior placement on the motion.

Material and Methods: We retrospectively reviewed 186 prosthesis implanted in 130 patients who underwent an LP Prestige cervical disc replacement and decompression. The distance between the posterior edge of the lower plate of the LP Prestige disc and the posterior wall of the corresponding vertebra was measured. The measurement was performed on a digitalized lateral view x-rays. The posterior placement measurement was correlated to the range of motion of the device on the same level and also on the level above and bellow.

Results: The average age was 46.7 years (range 33–66). The mean posterior placement was 2.96 mm (range 0–6 mm). Range of motion (full flexion to full extension) of the prosthesis was 9.41 degrees (range 0.2–22). Average followup was 2.3 years.

Statistical analysis showed no statistical significant correlation between the posterior placement of the disc and the motion of disc (flexion to extension, flexion to neural and neutral to extension). The p value was 0.259, 0.379 and 0.623 respectively. There was no correlation between the placement of the disc and the motion of the level above and bellow the operated level.

Conclusion: We conclude from our study that there is no correlation between the posterior placement of the Prestige LP and the segmental motion of the prosthesis and the level above and bellow.

Introduction: Cervical disc replacement has emerged as an alternative to the gold standard ACDF in ordered to preserve the motion of the cervical spine, and reduce the risk of adjacent degenerative changes. However, little data actually exists to support or refute the effect of symptoms chronicity on TDA for the treatment of degenerative cervical spine.

Material and Methods: We prospectively investigated 130 consecutive patients who have undergone a Prestige LP cervical disc replacement for degenerative disease causing chronic neck pain and radiculopathy.

The pre and post-operative NDI, SF-36, Visual Analogue Score (VAS), HDS and HAS were recorded.

Results: There were 130 patients in total. There were 66 males and 64 females, with an mean age at surgery was 51.12 +/− 0.84. Seventy five patients had one level disc replacement, and 56 had 2 levels.

The mean follow up was 28+/−0.35 months, and the mean duration of symptoms was 34.46 +/−3.8 months. Mean length of stay 1.75+/−0.11 (1–4)

There was no correlation between the DOS and any of the functional outcome:

Improvement Neck disability index (r=−0.181, p=0.134)

Improvement in HDS (r=−0.126, p=0.296)

Improvement in HAS (r=0.00, p=0.99)

Improvement in SF-36 bodily pain (r=−0.011, p=0.925)

Improvement in SF-26 mental health (r=0.042, p=0.324)

Improvement in VAS neck pain (r=−0.0120, p=0.324)

Improvement in VAS arm pain (r=0.0178, p=0.141)

Dividing the DOS into more or less than 12 months shows significant improvement only in the NDI: less than 12 months DOS (31.85±3.209) and in patients with more than 12 months DOS (19.71±2.164), p=0.002

While there was no statistical difference in the other outcomes.

Dividing the DOS into more or less than 24 months showed significant improvement the out come in patients with less than 24 months in the following outcomes:

Improvement in NDI: less than 24 months (27.35±2.714), more thank 24 months (19.72+2.435), p=0.04

Improvement in VAS arm pain: less than 24 months (4.6000±0.34446), more than 24 months (2.7414±3.7236), p=0.001

Improvement in hospital depression score: less than 24 months (5.37±0.589), more than 24 months (3.60±0.47), p-0.023

Improvement in hospital anxiety score: less than 24 months (4.28±0.49), more than 24 months (2.45±0.48), p=0.009

While there was no significant difference in the other outcomes

Dividing the DOS into less or more than 36 months showed no statistical difference in any of the outcome,

That was also the case when the DOS was divided into more or less than 48 months.

Conclusion: Duration of symptoms of more that 24 months was associated with less favorable outcome, that was evident in improvement in NDI, HDS, HAS and VAS arm pain. Patients should be counseled when they present with DOS more than 24 months.