RAMB - Dezembro

oaquim

892

ssoc

ras

2016; 62(9):886-894

A multitude of surgical procedures for expandable

laminoplasty were described, but we can group them in

two main techniques:

45,46

1. open-door or unilateral technique; and

2. double door laminoplasty (also known as French door,

spinous process-splitting, midline opening or T-saw

laminoplasty).

The open door technique is based on open the lamina in

one side (generally the most symptomatic one or with ra-

dicular symptoms) and hinge the contra-lateral side, where-

in a greenstick fracture is performed. The lamina can be

maintained in the open position with sutures or miniplates

(that offers immediate stability). In contrast, the double door

expands the spinal cord symmetrically by opening the mid-

line with a split of the spinous processes and hinging both

the left and right hemilaminae. The midline laminar splits

can be opened with laminar spreaders or bone graft.

41,45,46

While laminoplasty offers advantages over cervical

fusion, it is not indicated for all patients. It does not ad-

dress neck pain and may even cause worsening symptoms

compared with anterior approaches, with extensive pos-

terior muscle denervation. It is contra-indicated in patients

with loss of cervical lordosis and with segmental insta-

bility. Complications of laminoplasty may include C5

palsy (5 to 12%), cervical axial pain, decreasing in cervical

range of motion (ROM), and progression of OPLL.

28,41,46

Interestingly, although C5 palsy is associated classi-

cally with posterior decompression, Gandhoke reported

that the incidence of C5 palsy was similar comparing

anterior cervical corpectomy (31 cases)

versus

posterior

laminoplasty (31 cases as well).

There were two cases of

C5 nerve root pareses in each group (p=1). There was no

differences between the complication or reoperation rates

between the two groups (p=0.184 and p=0.238, respec-

tively). This study, however, was underpowered to assess

different complication rates.

Finally, laminoplasty requires some stabilization to

maintain the lamina in a new expanded position. The hard-

ware for laminar fixation may increase the cost of the pro-

cedure (such as titanium implants) and also add potential

complications (such as lamina migration, non union, hard-

ware subsidence, etc). Lastly, there is a risk of laminar door

closure with recurrence of neurological symptoms.

omparison

versus

posterior

approaches

for multilevel

DCM

Both anterior and posterior approaches are associated with

improvement in patients’ final neurological outcomes in

DCM. Some systematic reviews reported that there was a

trend towards better postoperative neural function with

anterior approaches, possibly explained by the fact that

anterior surgery is generally proposed for several forms of

the disease. However, the recovery rate was similar between

both according to systematic reviews with meta-analysis.

Of note, multilevel anterior cervical decompression and

fusion had a higher rate of complications compared with

posterior surgery.

Fehlings et al. performed a prospective observational

multicenter study of 264 patients comparing the anterior

and posterior surgical approaches to treat DCM.

The choice

of each approach was at the discretion of the surgeon and

a follow-up rate of 87% was obtained. Outcome measures

included the mJOA scale, Nürick scale, the Neck Disability

Index and SF-36 Health Survey

version

2 Physical and Men-

tal Component Scores. A total of 169 patients were treated

anteriorly and 95 received a posterior cervical surgery. DCM

patients who underwent anteriorly cervical surgery were

younger and had less severe myelopathy (as defined by the

mJOA andNürick scores). Both groups had similar baseline

Neck Disability Index and SF-36, but the mJOA was lower

in the posterior approach group. The extent of improvement

in the Nürick scale, Neck Disability Index, SF-36

version

Physical Component Score, and SF-36

version

2Mental Com-

ponent Score were similar between the groups, although the

mJOA improvement was lower in the anterior group (2.47

vs.

3.62, respectively, p<0.01). They concluded that, although

patients who underwent anterior cervical approach were

younger and had less severe DCM, both treatments had

similar efficacy in the treatment of DCM.

ombined

posterior

approaches

In selected cases, a combined anterior-posterior or pos-

terior-anterior approach can be used. The indications for

combined approaches include patients requiring oste-

otomies for releasing the spine, patients with high risk

for hardware failure, such as those with severe osteopo-

rosis, and patients with a failure of a previous surgical

approach (generally an anterior approach).

41,50-52

Combined

approaches may add morbidity of both anterior and pos-

terior surgeries, but must be considered in some challeng-

ing cases to successfully achieve the goals of surgery (de-

compression, stability and good cervical alignment). Of

note, patients with 2-stage surgery are at an increased risk

of experiencing major complications as they typically have

more extensive degenerative pathology.

onclusion

Cervical spondylotic myelopathy is the most common

cause of spinal cord dysfunction in adult patients. The