Adult scoliosis correction by direct vertebral translation technique 2 year clinical and radiographic results

2005

BACKGROUND CONTEXT

Luque introduced direct vertebral translation to the rod with sublaminar wires. A new technique for direct vertebral translation was developed using the 160 degree pivoting reduction post on a new Multi-Planar Adjusting (MPA) screw.

PURPOSE

This study was undertaken to evaluate whether direct vertebral translation applied through the MPA pivoting reduction post produces superior correction of adult scoliosis compared to other techniques.

STUDY DESIGN/ SETTING

This is a prospective analysis of 35 consecutive patients with adult scoliosis treated with posterior correction by one surgeon. The first 17 (control group) were corrected by rod derotation and in situ bending and followed 5 yrs (3-11 yrs). The next 18 patients (MPA group) were corrected by direct vertebral translation using the pivoting reduction post on the MPA screws and followed 3 yrs (24-41 mo).

PATIENT SAMPLE

The control group (15F, 2M) averaged 48 yrs (20–79 yrs). 12 were idiopathic and 5 were degenerative curves. The MPA group (17F, 1M) averaged 55 yrs (19–85 yrs). 13 had idiopathic and 5 had degenerative.

OUTCOME MEASURES

Oswestry and Visual Analog pain Scores (VAS), pain medication use, and work status were followed. Radiographs were obtained at 6 wks, and 3, 6, 9, 12, 24 mo, and yearly thereafter.

METHODS

Surgical indications included curve progression, spinal imbalance, failure of >6 mo conservative care. Both groups were corrected through a posterior instrumented fusion. In the MPA group, rods were bent to the desired spinal contour and the spine was pulled directly to the rod via the pivoting reduction posts on the MPA screws. This produced correction in both the coronal and sagittal planes. In the control group, deformity was corrected by rod derotation combined with in situ bending. Anterior surgery was required in 15 control and 16 MPA patients. Two patients from each group required osteotomies to mobilize ankylosed segments. Results were analyzed according to curve type.

RESULTS

The MPA group curves of 54° (17–83 deg) corrected 70% to 16° (4-40 deg) was better (P<0.01) than control group curves of 55° (25–84 deg) corrected 48% to 29° (10-59 deg). Degenerative lumbar scoliosis showed the biggest difference with MPA group curves of 45° (17–83 deg) correcting 78% to 9° (4–18 deg) compared to control group of 40° (25–54 deg) corrected 44% to 29° (10–37 deg). Idiopathic scoliosis of 57° (43–83 deg) in the MPA group corrected 69% to 17° (7–40 deg) compared to 49% correction in the control group. Control group complications included 3 nonunions, 2 cases of implant pullout, 1 broken rod, 1 infection. The MPA group had 3 nonunions, 2 infections, no cases of screw pullout during reduction. Oswestry and VAS scores were similar for both groups, showing significant improvements in pain and function at 1 and 2 years.

CONCLUSION

In the past, pulling a vertebra from any direction to a rod (direct vertebral translation) has only been achievable through sublaminar wires or cables. This study shows statistically improved correction of adult scoliosis by direct vertebral translation using the pivoting reduction posts attached to the Multi-Planar Adjusting screws. The most dramatic improvement was seen in patients with degenerative lumbar scoliosis. The technique appears to be very promising in patients with adult scoliosis.