C3-6 laminoplasty takes over C3-7 laminoplasty with significantly lower incidence of axial neck pain

Risk factors for closure of lamina after open-door laminoplasty

Object

This retrospective study was conducted to evaluate the prevalence and clinical consequences of postoperative lamina closure after open-door laminoplasty and to identify the risk factors.

Methods

Eighty-two consecutive patients with cervical myelopathy who underwent open-door laminoplasty without plates or spacers in the open side (Hirabayashi's original method) were included (62 men and 20 women with a mean age of 62 years and a mean follow-up of 1.8 years). In 67 patients the cause of cervical myelopathy was spondylotic myelopathy, and in 15 it was caused by ossification of posterior longitudinal ligament. Radiographic measurements were made of the anteroposterior diameters of the spinal canal and vertebral bodies from C3–6, and the presence of kyphosis were assessed. Lamina closure was defined as ≥ 10% decrease in the canal-to-body ratio at the final follow-up compared with that immediately after surgery at ≥ 1 vertebral level. The impact of lamina closure on neck pain, patient satisfaction, Japanese Orthopaedic Association scores, and recovery rates were also evaluated.

Results

The mean canal-to-body ratio at C3–6 was 0.69–0.72 preoperatively, 1.25–1.28 immediately after surgery, and 1.18–1.24 at the final follow-up examination. Lamina closure was observed in 34% of patients and was not associated with sex, age, or cause of myelopathy, but was significantly associated with the presence of preoperative kyphosis (p = 0.014). Between patients with and without lamina closure, there was no significant difference in preoperative (9.7 ± 3.1 vs 10.6 ± 2.5) and postoperative (13.7 ± 2.4 vs 13.1 ± 2.7) Japanese Orthopaedic Association scores, recovery rates (53.9 ± 29.9% vs 44.3 ± 29.5%), neck pain scores (3.5 ± 0.7 vs 3.3 ± 1.0), or patient satisfaction level (4.0 ± 1.4 vs 4.8 ± 1.0).

Conclusions

Lamina closure at ≥ 1 vertebral level occurred in 34% of patients. Although patients with lamina closure obtained equivalent recovery from myelopathy in a short-term follow-up, they tended to be less satisfied with surgery compared with those who did not have closure. The only significant risk factor identified was the presence of preoperative cervical kyphosis, and preventative methods for lamina closure, therefore, should be considered for patients with preoperative kyphosis.

Preservation of the nuchal ligament plays an important role in preventing unfavorable radiologic changes after laminoplasty

STUDY DESIGN

Prospective study.

OBJECTIVE

To examine whether preservation of the funicular section of the nuchal ligament attached to the C6 and C7 spinous processes could prevent unfavorable radiologic changes such as kyphotic deformity and destabilization at the C6/7 segment, and to investigate possible correlations between adverse radiologic changes and neurologic recovery or incidence of axial neck pain after laminoplasty in patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Adverse radiologic changes after cervical laminoplasty have been reported to result from detachment of cervical extensor muscles.

METHODS

Subjects comprised 37 patients who underwent modified C3-6 laminoplasty. Our procedure preserves the funicular section of the nuchal ligament attached to the C6 and/or C7 spinous processes in addition to all muscles attached to the C2 and C7 spinous processes and the subaxial deep extensor muscles on the hinged side. The funicular section of the ligament attached only to the C7 spinous process was preserved in 18 patients (C7 group). This funicular section attaching both to the C7 and C6 spinous processes was preserved in 19 patients (C6+7 group). Radiologic and clinical data were prospectively collected.

RESULTS

Postoperative loss of lordosis and destabilization at the C6/7 segment were significantly reduced in the C6+7 group compared with the C7 group. As of final follow-up, neurologic recovery was significantly poorer in the 3 patients with kyphosis than in the 34 patients with straight spinal alignment or lordosis. Frequencies of axial pain showed no significant differences between groups. This value did not vary with the differences in sagittal alignment.

CONCLUSIONS

These results indicate that the preserved funicular section of the nuchal ligament attached both to the C6 and C7 spinous processes plays an important role in preventing undesirable radiologic changes after laminoplasty.

Surgical anatomy of the nuchal muscles in the posterior cervicothoracic junction: significance of the preservation of the C7 spinous process in cervical laminoplasty

STUDY DESIGN

An anatomic study investigated the attachment of the nuchal muscles to the spinous process.

OBJECTIVE

To investigate the anatomic details of the attachment of the nuchal muscles to the spinous process, and which muscles are spared, and to what extent, when the C7 spinous process is preserved in the cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

In previous studies, it was reported that the incidence of postoperative axial pain was lower in C3-C6 laminoplasty than in C3-C7 laminoplasty, emphasizing the effectiveness of the former procedure where discission of the nuchal muscles that are attached to the C7 spinous process is avoided. However, there have been no detailed anatomic studies of the attachment of the nuchal muscles to the spinous process at the cervicothoracic junction.

METHODS

The anatomy of the speculum rhomboideum of the trapezius, rhomboideus minor, rhomboideus major, serratus posterior superior, splenius capitis, and splenius cervicis to the spinous processes of the cervicothoracic junction were studied using 50 cadavers.

RESULTS

The possibility of total discission of the speculum rhomboideum of the trapezius was 0% with C3-C6 laminoplasty and 18% with C3-C7 laminoplasty. More than 50% preservation of the speculum rhomboideum of the trapezius is possible in 72% in C3-C6 laminoplasty and 16% in C3-C7 laminoplasty. In C3-C7 laminoplasty, the possibility of partial preservation of the rhomboideus minor, serratus posterior superior, and splenius capitis at the spinous process was 0%, 66%, and 29%, respectively. The rhomboideus major in 16% and the splenius cervicis in 56% could be completely preserved without partial discission of the muscle attachment. On the other hand, in C3-C6 laminoplasty, the muscles that were spared without complete discission of the muscular attachment at the spinous process were the rhomboideus minor in 35%, the serratus posterior superior in 100% and the splenius capitis in 67%. The rhomboideus major in 76% and the splenius cervicis in 80% were completely spared without partial discission of the muscular attachment.

CONCLUSION

The current study confirmed that C3-C6 laminoplasty in which the C7 spinous process is preserved reduces invasion of the nuchal muscles.

The source of axial pain after cervical laminoplasty-C7 is more crucial than deep extensor muscles

STUDY DESIGN

Prospective study to investigate the incidence of axial pain in the 3 different procedures of laminoplasty.

OBJECTIVE

To inquire which is more important in the development of axial pain after laminoplasty: C7 or deep extensor muscles.

SUMMARY OF BACKGROUND DATA

The etiology of axial pain remains largely unknown. Some surgeons have attempted to preserve the paravertebral muscles with innovative procedures of laminoplasty and thereby reduce the incidence of axial pain. Meanwhile, we have reported that axial pain can be prevented by avoiding inclusion of C7 in laminoplasty.

METHODS

There were 91 patients with myelopathy who underwent our original laminoplasty, in which the deep extensor muscles were completely preserved exclusively on the hinged side. Until 2001, all candidates for laminoplasty underwent this procedure from C3-C7 (left-opened C3-C7 group, n = 37). From 2002, the same procedure was performed from C3-C6 (left-opened C3-C6 group, n = 31). From 2004, the opened side was changed from left to right (right-opened C3-C6 group, n = 23). Axial neck pain was graded as severe, moderate, or mild. Early pain during the first month after surgery and late pain during the first year after surgery were investigated. The laterality of early pain in the C3-C6 groups was recorded.

RESULTS

Significant early pain graded severe or moderate was observed in 49% in the left-opened C3-C7 group, but 15% in the left- or right-opened C3-C6 groups (P = 0.0008). Significant late pain was noted in 30% in the left-opened C3-C7 group and in 5.6% in the C3-C6 groups (P = 0.0036). Early axial pain, which usually was mild, was predominantly observed on the opened side in the C3-C6 groups.

CONCLUSION

To prevent axial pain, C7 should not be included in cervical laminoplasty, while detachment of the deep extensor muscles does not result in significant axial pain.

Persistent local pain after posterior spine surgery for thoracic lesions

Many surgeons have investigated local pain associated with posterior spine surgery for cervical or lumbar lesions. However, little information is available concerning local pain after posterior thoracic spine surgery. This prospective study was, thus, performed to investigate the frequency and clinical features of local pain after posterior spine surgery for thoracic lesions. In 29 consecutive patients undergoing posterior spine surgery for various thoracic spinal disorders, local pain was investigated before and after surgery. In all 19 patients with preoperative back pain presumably due to thoracic lesions, pain was well alleviated after surgery. In contrast, 6 patients (21%) newly developed persistent shoulder angle pain after surgery, which resembled axial pain after cervical laminoplasty. In 5 of these 6 patients surgical exposure was extended to the cervicothoracic junction, whereas persistent shoulder angle pain was independent of disease etiologies and surgical procedure, and all of the 5 patients had no other etiologies of local pain such as surgical site infections, hardware failures, pseudoarthrosis, other metastasis, and vertebral fractures. These results suggest that dissection of muscle attachments to the cervicothoracic junction would play some part in the development of persistent local pain after posterior spine surgery for thoracic lesions, although surgical exposure of the zygapophysial joints at the cervicothoracic junction might be a possible source of postoperative shoulder pain. Therefore, to minimize such surgical complications, muscle insertions into the cervicothoracic junction should be preserved as far as possible.