Surgical outcomes in patients with mild symptoms, but severely compressed spinal cord from cervical ossification of the posterior longitudinal ligament.

ABSTRACT

Surgical treatment is indicated in patients with moderate to severe myelopathy from cervical ossification of the posterior longitudinal ligaments (OPLL), but undertaking prophylactic surgery for asymptomatic or mildly symptomatic patients with a severely compressed spinal cord is debatable. Patients with <8mm space available in the spinal canal on CT scan, were divided into groups I (mild symptoms, Japanese Orthopedic Association (JOA) score range 15-16) and II (moderate to severe symptoms, JOA score <14). Medical charts including operative records were reviewed to obtain preoperative, perioperative, and final postoperative follow-up data. Group I included 24 patients (20 men, mean age 52.42years), and Group II included 46 patients (33 men, mean age 54.67years). Compared to Group II, Group I had a shorter preoperative symptom duration (19.21 vs. 38.23months, p=0.046) and a more favorable JOA score at final follow-up (p=0.007). The mean numbers of OPLL-involved segments were similar (Group I 2.96, Group II 3.09; p=0.773) as were the mean numbers of operated segments (Group I 2.71, Group II 3.35; p=0.076). Perioperative blood loss, operation duration, and hospital stay duration were significantly more favorable in Group I than in Group II. The numbers of surgery-related complications in the two groups were similar. Early surgical treatment for a favorable neurologic recovery with a low perioperative risk can be recommended in patients with severely compressed spinal cord from cervical OPLL who present with mild arm numbness. Surgery-related complications, however, should be carefully monitored regardless of symptom severity.