MW construct in fusion for neuromuscular scoliosis

Abstract

A retrospective case control review was conducted to determine if the MW construct offers a superior means of correction of Cobb angles and pelvic obliquity in neuromuscular scoliosis. Posterior spinal fusion (PSF) in patients with neuromuscular scoliosis presents a surgical challenge. Particularly difficult is the correction of pelvic obliquity. Numerous instrumentation techniques have sought to address these difficulties. Most recently Arlet et al have introduced the MW construct. (in Eur Spine 8(3):229-231, 1999). They theorize that this construct may allow for superior spinopelvic fixation. Six patients with neuromuscular scoliosis who underwent PSF with the MW construct were compared with six subjects undergoing PSF utilizing the Galveston technique. Subjects were matched on the basis of preoperative Cobb angles and similar amounts of preoperative pelvic obliquity. Individuals who underwent PSF utilizing the MW construct obtained nearly 30% better correction of pelvic obliquity than did those who received a Galveston construct. A trend toward superior correction of Cobb angles with the MW construct was also observed. The MW construct may be a superior construct for curve correction in PSF for neuromuscular scoliosis, particularly those cases with excessive pelvic obliquity.

Fig. 1

One preoperative and two postoperative images demonstrating the radiographic appearance of the MW construct on AP and lateral views

Fig. 2

Anteroposterior image of a neuromuscular scoliosis patient which demonstrates the technique employed by the authors to measure Cobb angles and pelvic obliquity, in both a degree and distance measurement

Fig.3

Graphical representation of the mean preoperative and postoperative Cobb angles for patients in both the MW and Galveston group

Fig. 4

Graphical representation of the percent correction of the Cobb angle in each study group. Note the improved correction in Cobb angles in those undergoing fusion with the MW construct

Fig. 5

Graphical representation of the average amount of preoperative and postoperative pelvic obliquity (in a degree measurement) for the MW and Galveston groups

Fig. 6

Similar representation to that presented in Fig. 5, however, with pelvic obliquity as measured in distance (cm)

Fig. 7

Graphical demonstration of the superior correction of pelvic obliquity in those undergoing fusion with the MW construct as demonstrated by percent correction in each respective study group