Localization of the Medial Branches of the Cervical Dorsal Rami During Cervical Laminoplasty

Study Design. Observational anatomic study. Objective. To give precise information on the surgical anatomy of the medial branches of the cervical dorsal rami. Summary of Background Data. The anatomy of the medial branches has not been sufficiently described. Methods. We recorded the location of the medial branches in 94 consecutive patients who underwent laminoplasty for cervical compression myelopathy. A posterior cervical approach was made along the edge of the nuchal ligament, and, after carefully detaching the trapezius muscle from the nuchal ligament; we identified the right-side branches around the semispinalis capitis muscle. We recorded the location of the branches with reference to the spinous processes and the semispinalis capitis and trapezius muscles. In 52 patients, we electrically stimulated the branches and observed the contraction of these muscles. Results. Branches were identified between C3 and C6 spinous process levels in 92 patients. A single branch was identified in 56 patients, 2 branches were identified in 35 patients, and 3 branches were identified in the remaining 1 patient. Branches were located between C3 and C4 (n = 12), between C4 and C5 (n = 80), between C5 and C6 (n = 2), and at C6 (n = 35). There were 4 patterns of final course: 52 branches passed through the medial side of the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 50 branches penetrated the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 12 branches terminated in the semispinalis capitis muscle; and 15 branches penetrated the semispinalis capitis and terminated at the nuchal ligament. In 19 of 52 patients tested, the semispinalis capitis muscle contracted after electrical stimulation. Conclusion. Medial branches of the cervical dorsal rami were discernible in cervical posterior approach laminoplasty and were frequently found adjacent to C4 and C5 spinous processes. The medial branches sometimes supplied motor fibers to the semispinalis capitis muscle. Knowledge of the course of these branches might be helpful for avoiding injury during laminoplasty.

[1]  Y. Hoshino,et al.  Long-term results of double-door laminoplasty using hydroxyapatite spacers in patients with compressive cervical myelopathy , 2011, European Spine Journal.

[2]  L. Dai,et al.  Axial pain after posterior cervical spine surgery: a systematic review , 2011, European Spine Journal.

[3]  A. Minami,et al.  Minimum 2-year outcome of cervical laminoplasty with deep extensor muscle-preserving approach: impact on cervical spine function and quality of life , 2009, European Spine Journal.

[4]  H. Toyoda,et al.  Effect of Preserving Paraspinal Muscles on Postoperative Axial Pain in the Selective Cervical Laminoplasty , 2008, Spine.

[5]  Y. Matsuyama,et al.  Laminoplasty and Skip Laminectomy for Cervical Compressive Myelopathy: Range of Motion, Postoperative Neck Pain, and Surgical Outcomes in a Randomized Prospective Study , 2007, Spine.

[6]  Y. Toyama,et al.  Long-term Results of Expansive Open-Door Laminoplasty for Cervical Myelopathy−Average 14-Year Follow-up Study , 2006, Spine.

[7]  S. Toh,et al.  Axial Symptoms After Cervical Laminoplasty With C3 Laminectomy Compared With Conventional C3–C7 Laminoplasty: A Modified Laminoplasty Preserving the Semispinalis Cervicis Inserted into Axis (Presented at the 2004 CSRS Meeting) , 2005, Spine.

[8]  Y. Yato,et al.  Results of Skip Laminectomy—Minimum 2-Year Follow-up Study Compared With Open-Door Laminoplasty , 2003, Spine.

[9]  S. Hirabayashi,et al.  Surgical Anatomy of the Nerves and Muscles in the Posterior Cervical Spine: A Guide for Avoiding Inadvertent Nerve Injuries During the Posterior Approach , 2003, Spine.

[10]  K. Takeshita,et al.  Long-Term Results of Double-Door Laminoplasty for Cervical Stenotic Myelopathy , 2001, Spine.

[11]  K. Saita,et al.  COMPLAINT OF NUCHAL PAIN FOLLOWING CERVICAL LAMINOPLASTY , 1999 .

[12]  K. Yonenobu,et al.  Neck and Shoulder Pain After Laminoplasty: A Noticeable Complication , 1996, Spine.

[13]  N. Bogduk.  The Clinical Anatomy of the Cervical Dorsal Rami , 1982, Spine.