Long-term outcomes of prosthetic disc nucleus placement via anterior mini-open approach for degenerative lumbar disc disease

English Keywords:Degenerative lumbar disc disease  Prosthetic disc nucleus replacement  Mini-open approach  Outcomes  Long-term

English Abstract:

  【Abstract】 Objective：To analyze the long-term outcome of prosthetic disc nucleus（PDN） placement by mini-open retroperitoneal approach for degenerative lumbar disc disease.Method：12 cases with degenerative disc disease underwent single PDN placement from June 2003 to September 2004.There were 4 males and 8 females with the average age of 28.5±8.4 years old.There were 10 cases of lumbar disc herniation and 2 cases of discogenic low back pain.Visual analoge scale（VAS） score for leg and low back pain，and Oswestry disability index（ODI），MacNab clinical efficacy，PDN location，intervertebral height in diseased level or above and lumbar range of motion（ROM） at preoperation，3 months，1 year and final follow-up after surgery were reviewed statistically.Result：The average follow-up was 73.6±8.3 months.As for VAS leg and low back pain score and ODI score：significant differences（P<0.05） were noted between 3 months′ follow-up and preoperation as well as between 1 year and 3 months′ follow-up，however no difference between final and 1 year follow-up（P>0.05）.As for diseased disc height：significant difference（P<0.05） was showed at 3 months compared with preoperation and 1 year，but no difference between final follow-up and 1 year was noted（P>0.05）.Adjacent proximal disc height remained unchanged till 1 year，but no statistical difference was noted between final follow-up and 1 year（P>0.05）.Lumbar ROM at 3 months showed no statistical difference compared with preoperation and 1 year respectively（P>0.05），and statistical difference was noted between final follow-up and 1 year（P<0.05）.MacNab scale showed excellent to good ratio of 83.3%.No PDN displacement was noted.Modic change occurred at diseased level in all patients at final follow-up under T2-weighted MRI.Conclusion：Anterior mini-open retroperitoneal PDN placement for degenerative lumbar disc disease can improve outcome and prevent PDN displacement as well as restore adjacent segment height，however end-plate injury of diseased disc is common.