Postoperative hematoma is a rare and dangerous complication of cervical spine surgery. The aim of this study was to investigate the incidence and related factors of postoperative hematoma, and to report on 15 cases at our institution over a 6-year period.

Fifteen cases of postoperative hematoma were retrospectively identified. We investigated their neurological outcomes, characteristics, and surgical data, and identified risk factors associated with postoperative (PO) hematoma. Patients with hematoma were compared to those with no hematoma, in order to identify risk factors.

Retropharyngeal hematomas developed in seven cases and epidural hematomas in eight. The total incidence of postoperative hematoma was 1.2%: 0.5% retropharyngeal hematomas and 0.6% spinal epidural hematomas. At time of onset, the severity of paralysis was assessed as grade B in one case, grade C in six cases, and grade D in eight cases. Risk factors for PO hematoma were: (1) presence of ossification of the posterior longitudinal ligament (OPLL) (P<0.001); (2) longer operative duration (P=0.048); (3) greater number of surgical levels (P=0.02); and (4) higher body mass index (BMI; P=0.035). There was no significant difference in modified Japan Orthopedic Association scores between the hematoma group and non-hematoma group (P>0.05).

Precise preoperative preparation and systematic evaluation are central to successful management of PO hematoma after anterior cervical surgery. Risk factors for PO hematoma include multilevel decompression, OPLL, higher BMI, and longer operation time.