Scarcity of Implants Has Partially Replaced Cervical Spondylotic Myelopathy Decompression and Instrumented Fusion with Implant-Less Expansile Cervical Laminoplasty: Poverty Teaches all the Arts.

OBJECTIVE

The scarcity of implants during the economic crisis partially has replaced decompression and instrumented fusion for the treatment of cervical spondylotic myelopathy with implant-less expansile cervical laminoplasty (ECL). The aim of the study was to compare the results obtained with instrumented anterior cervical corpectomy and fusion with implant-less ECL.

METHODS

Patients suffering from cervical spondylotic myelopathy Nurick 3-5 with preoperative tethering and postoperative untethering were included. Exclusion criterion was kyphosis more than 10°. Patients were assessed according to 30-meter walking track (30mWT), Nurick, and modified Japanese Orthopaedic Association scale scores. Kinematic magnetic resonance imaging 3-dimensional subaxial spinal cord reconstructions were 3 dimensionally modeled to confirm preoperative pincer clamping and follow-up unclamping to measure subaxial spinal cord length and pia envelope area (PEA).

RESULTS

A total of 35 patients divided in the ECL (n = 19) and the anterior cervical corpectomy and fusion (n = 16) groups were selected from 534 patients operated on between September 1, 2008, and August 31, 2013 as the result of degenerative cervical disorders. Patients improved according to Nurick and modified Japanese Orthopaedic Association scores without differences between groups. Follow-up 30mWT analysis showed greater decrease in steps number and time in ECL group, creating the basis for further imaging analysis. Magnetic resonance imaging analysis showed that spinal cord length (mm) shortened more (4.47 ± 1.87 vs. 1.5 ± 2.5, t = -4.02; P = 0.0003) and PEA (mm2) shrank more (95.58 ± 43.73 vs. 22.94 ± 33.11, t = -5.45, P < 0.0001) in the ECL group. Multivariate logistic analysis showed that Δ 30mWT-time and Δ PEA were a very predictive model when area under the receiver operating characteristic curve is 0.98.

CONCLUSIONS

Our results created a nidus for further research of postdecompression spinal cord relaxation.