Case report

Case report

Early Bony Healing of Cervical Laminoplasty Hinge

Patrick Fransen, MD (1), Bart Depreitere MD, PhD (2)

1Department of Neurosurgery, Clinique du Parc Leopold CHIREC, Brussels,Belgium

2Department of Neurosurgery, UZ Gasthuisberg,Leuven, Belgium  

Correspondence author: Department of Neurosurgery, winter park, 38 rue froissart, 1040 brussels, belgium; E-mail:, Fax:  + 322 287 5654, Telephone: +322 287 5650

Citation:  Fransen P, Depreitere B: Early Bony Healing of Cervical Laminoplasty. J Minim Invasive Orthop, 2015,2(2):e9. doi:10.15383/jmio.9.

Competing interests: The authors have declared that no competing interests exist.

Conflict of interest: None

Copyright: 2015 By the Editorial Department of Journal of Minimally Invasive Orthopedics. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Abstract:Cervical laminoplasty is progressively gaining attention as a valuable option to treat cervical spondylotic myelopathy, allowing spinal cord decompression without fusion and producing outcomes comparable or superior to laminectomy. We report the early healing of a laminoplasty hinge after infection and removal of the metallic implants. We report the observation of a 69 year old patient presenting with cervical myelopathy, treated with a C6C7 open door laminoplasty. Early S. Aureus infection necessitated early removal of the laminoplasty implants.  During the operation,the uplifted posterior arches seemed stable. The metallic supports were removed and no further surgical action was performed. The infection healed and the patient did well afterwards. The two years radiological follow-up showed no collapse of the lamina. This observation may indicate that the laminectomy hinge can heal as early as two months after surgery. If this is the case, the metallic spacers could be replaced by shorter-lived resorbable implants.

Keywords:Open-door laminoplasty, cervical myelopathy,spondylosis,infection


Since its introduction in the early seventies in Japan by Hattori et al, followed by Tsuji and Hirabayashi [1-3], cervical laminoplasty, is progressively gaining attention as a valuable option to treat cervical spondylotic myelopathy, allowing spinal cord decompression without fusion and producing outcomes superior to cervical laminectomy, [4-7] . Recently, Yoon et al reported that for cervical spondylotic myelopathy, laminoplasty and laminectomy-fusion procedures are similarly effective [8], laminoplasty having the advantage of being a motion sparing surgery. Several techniques (open- door versus open-book) and different types of implants (sutures, staples, unilateral or bilateral metallic spacers or plates) are available [9]. We report on an observation of early bony healing in a case with early removal of the laminoplasty implants for reasons of infection, which could help to understand what type of implant would be sufficient.

Case report

A 69 year old patient presented with painful paresthesias in the four limbs, associated with right hand clumsiness for fine movements and episodes of weakness in the right leg causing gait imbalance.The cervical MRI scan showed spinal canal narrowing at the C5C6 and C6C7 levels. The preoperative Benzel modified JOA score was 14 and the Nurick score was 2.The diagnosis of cervical myelopathy was made and based on the imaging, the open-doorlaminoplasty technique was considered a good option. After patient consent, two metallic spacers (Centerpiece, Medtronic Inc., Memphis USA) were implanted to keep the uplifted C6 and C7 laminas in place, with a good clinical result. After one month, the Benzel JAO score was 16 and the Nurick score was 1.

The patient developed a postoperative Staphylococcus Aureus deep seated infection and the implants had to be removed 2 months after the index surgery. A CT scan performed before the surgery could not assess bony healing of the hinge, and therefore, the patient was initially scheduled for implant removal and laminectomy. During the operation, the uplifted posterior arches seemed stable. The metallic supports were removed and no further surgical action was performed.

The patient was followed clinically. After 6 months, the Benzel JOA score was 18 and the Nurick score was 1. After one year, the Benzel JAO score was 18 and the Nurick score was 0.

The patient was followed during two years clinically and radiologically by CT scan and cervical spine X-rays. There was no change in vertebral alignment and no collapse of this unsupported lamina was observed.


Cervical spondylotic myelopathy is a common condition, often warranting surgical treatment. In a retrospective study, Halvorsen et al reported that the incidence of laminectomy or laminoplasty for cervical spondylotic myelopathy was 2.0/100,000 inhabitants per year (in Norway). In his series of 318 patients, five (1.6%) were reoperated because of postoperative infection [10].

The time it takes for the hinge hairline fracture  to heal has rarely been studied.By acomputed tomography scan review of the laminoplasty hinge, Rhee et al demonstrated that 55% of levels were healed at 3 months, 77% at 6 months, and 93% at 12 months [11]. What pressure the uplifted lamina has to endure from the neck muscles after the surgery is unknown.

In the present case, the metallic spacer, without bone graft, was probably only useful for a very short period of time, as for this patient, complete healing if the hinge was obtained after two months. Long term follow up confirmed that the hinge was strong enough to preserve the widening of the spinal canal. The influence of the infection on the healing process in unclear, but it is possible that it could have speeded up the process because of the local inflammatory response.

If other reports confirm that the laminectomy hinge heals in two months, this may be an incentive to look for easier and/or cheaper solutions to temporarily keep the arch in its new position until the hinge has fused, and on the condition they are safe with respect to the spinal cord. The use of metallic spacers for such a short period of time could therefore be unnecessary. A resorbable spacer could be an alternative option, with the advantage of avoiding the postoperative metallicartifacts on the MRI.

[1] Kawai S,Sunago K,Doi K,Saika M, Taguchi T: Cervical laminoplasty (Hattoris method). procedure and follow-up results. Spine 1988;13:1245C50.

[2] Hirabayashi K, Watanabe K, Wakano K, Suzuki N, Satomi K, Ishii Y: Expansive open-door laminoplasty for cervical spinal stenotic myelopathy. Spine (Phila Pa 1976).1983 Oct;8(7):693-9.

[3] Tsuji H:Laminoplasty for patients with compressive myelopathy due to so-called spinal canal stenosis in cervical and thoracic regions. Spine (Phila Pa 1976). 1982 Jan-Feb;7(1):28-34.

[4] Kode S, Gandhi AA, Fredericks DC, Grosland NM, Smucker JD : Effect of Multi-Level Open Door Laminoplasty and Laminectomy on Flexibility of the Cervical Spine:An Experimental Investigation. Spine 1;37(19):E1165-70, 2012.

[5] Machino M,Yukawa Y, Hida T, Ito K, Nakashima H, Kanbara S, Morita D, Kato F: Cervical Alignment and Range of Motion After Laminoplasty:Radiographic Data from Over 500 Cases With Cervical Spondylotic Myelopathy and a review of the literature. Spine 15; 37(20):E1243-50, 2012.

[6] Manzano GR,Casella G,Wang MY,Vanni S, Levi AD: A prospective,randomizedtrial comparing expansile cervicallaminoplasty and cervical laminectomy and fusion for multilevel cervical myelopathy. Neurosurgery 70(2):264-77, 2012.

[7] Matz PG,Anderson PA, Groff MW, Heary RF, Holly LT, Kaiser MG, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Resnick DK: Cervicallaminoplasty for the treatment of cervical degenerative myelopathy.  J Neurosurg Spine 11(2):157-69, 2009.

[8] Yoon T,Hashimoto R, Raich A, Shaffrey C, Rhee J, Riew D. : Outcomes following laminoplasty compared with laminectomy and fusion in patients with cervical myelopathy: A systematic review. Spine (Phila Pa 1976). 2013 Aug 16.

[9] Park AE, Heller JG:Cervical laminoplasty: use of a novel titanium plate to maintain canal expansion--surgical technique.J Spinal Disord Tech. 2004 Aug; 17(4):265-71.

[10] Halvorsen CM,Lied B,Harr ME,Rønning P, Sundseth J, Kolstad F, Helseth E:Surgical mortality and complications leading to reoperation in 318 consecutive posterior decompressions for cervical spondylotic myelopathy.Acta Neurol Scand. 2011 May;123(5):358-65.

[11] Rhee JM,Register B, Hamasaki T, Franklin B:Plate-only open door laminoplasty maintains stable spinal canal expansion with high rates of hinge union and no plate failures.

Figure 1.Postoperative lateral cervical CT scan reconstruction showing a deep            seated abscess at the laminoplasty site.(arrow).

Figure 2.Postoperative axial cervical CT scan showing the laminoplasty implant and the widening of the spinal canal.

Figure 3.Postoperative axial cervical CT scan one year after the removal of the implant showing identical dimensions of the spinal canal compared to figure 3

Figure 4.Postoperative lateral cervical  CT scan reconstruction showing the widened spinal canal one year after surgery.






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