BACKGROUND: As a novel procedure in minimally invasive spine surgery (MISS), percutaneous laser disc decompression(PLDD) has been applied widely in the recent development in clinical practices.OBJECTIVE: This study was designed to evaluate the influences of PLDD on the stability in cervical spinal constructs.DESIGN: A before-after comparison trail based on patients.SETTING: The experiment was performed at the spine surgery department of a hospital affiliated to a university.PARTICIPANTS: Twenty-eight patients who were diagnosed as lateral cervical disc herniation at the Spine Surgery Department of Shenzhen People' s Hospital, Second Hospital Affiliated to Jinan University were involved from October 2001 to April 2003. Of all of the patients, 17 were male and 11 were female. They have 29 cervical disc protrusions altogether.INTERVENTIONS: Monitored by X-ray, a 400 μm fixed optical fiber was introduced into the injured intervertebral disc via a 9-gauge flexible trocar through an anterior cervical approach. An Nd-YAG laser system,with a 1 060 nm wavelength and an output power of 15W, was employed to ablate or decompress the inner disc tissue. The disc tissue was exposedto 500- 950 J laser powers.MAIN OUTCOME MMEASURES: Before and 6 months after the PLDD, the deviation of adjacent vertebra displacements was observed and changings of the wedge angles of the intervertebral discs were calculated respectively.RESULTS: The deviation of adjacent vertebra displacements showed no significant difference between before and after operation, when the patients were examined with a more flexed-position or a more extended-position(t=0.811 7-0.827 2, P＞ 0.05), and no significant changes in the wedge angles of the intervertebral discs could be observed either(t=0.768 7-0.827 1,P ＞ 0.05).CONCLUSION: Applying percutaneous laser disc decompression to lateral cervical disc herniation has many advantages, such as simplicity of operation, minimal invasion and having no impact on the stability in cervical spinal constructs.