The impact of the loss of attachment in Hirayama disease patients treated with anterior cervical discectomy and fusion / 中华骨科杂志

ABSTRACT

Objective　To investigate the impact of the loss of attachment on the outcomes in Hirayama disease(HD)patients treated with anterior cervical discectomy and fusion(ACDF).Methods　A total of 26 patients(23 males and 3 females)who were diagnosed as HD and received 2 levels of ACDF surgery from February 2014 to November 2016 were enrolled in the present study.All patients took the MRI at both flexion and neutral position pre-operation and MRI at flexion position post-operation.The measured parameters related to performance of "loss of attachment" includethe distances between the posterior edge of the spinal cord and the cervical spinal canal(x),the anterior and posterior wall of the cervical spinal canal(y),the anterior-posterior(a)and the transverse diameter(b)of spinal cord cross sections.The value of the cervical spinal cord deformation(flexion position a/b)and the cervical spinal cord forward movement(flexion position x/y-neutral position x/y)were calculated,and the centrums refer to the performance of "loss of attachment" were also recorded.DASH scores and grip strength on both sides were recorded before and 1 year after operation.The 26 patients were divided into two groups,17 patients(17/26,65.4%)in improvement group with the decreased DASH scores and the other 9 patients(9/26,34.6%)in no improvement group.Logistic regression and ROC curve were used to analyze the influence factor of anterior cervical discectomy and fusion(ACDF)surgery on patients with Hirayama disease.Results　After surgery,the value of a/b significantly increased(t=4.27,P=0.001)and x/y significantly decreased(t=10.25,P=0.001).The performance of "loss of attachment" in 88.5%(23 of 26)patients disappeared after surgery,while the DASH score(P=0.06),and the grip strength of severe and mild side(P=0.36 and P=0.42)shew no obvious change.65.4%(17 of 26)patients shew a decrease in DASH scores after operation,the remaining 34.6%(9 of 26)patients shew no obvious change,several even with a mild increase.The segments refer to performance of "loss of attachment",the value of the cervical spinal cord de-formation and the cervical spinal cord forward movement shew a difference between the two group(t=-5.56,P=0.001;t=3.06,P=0.005;t=-3.76,P=0.001).The logistics regression analysis with the above three independent variable confirmed that the value of segments that refer to "loss of attachment" was the factor of the post-operative efficacy of ACDF surgery on patients with Hirayama disease(OR=6.963,P=0.001).And the ROC curve shew AUC=0.902,Jordan index=0.83,critical value=4.5.Conclusion　The anterior cervical discectomy and fusion(ACDF)surgery can effectively improve the loss of attachment at the surgical segments,and prevent the progress of upper limb dyskinesia.And range of the longitudinal separation refers to "loss of attachment" can impact the outcomes of ACDF surgery,more segments for fusion may be need in order to improve the outcomes of those patients with the range more than 5 segments.