SAFETY OF PEDICLE SCREW PLACEMENT FOR SPINAL DEFORMITY AT A PEDIATRIC ORTHOPAEDIC CENTER

Ann Golden, M.D.;
Daniel J. Sucato, MD, MS
Texas Scottish Rite Hospital, Dallas, TX, USA

INTRODUCTION:
Pedicle screws have been utilized for the treatment of adult spinal conditions with good results for many years. The use of pedicle fixation has been extended to the pediatric patient with good results recently reported by spinal orthopaedic surgeons.

OBJECTIVE:
To evaluate the safety of pedicle screws placed by pediatric orthopaedic surgeons for spinal deformity at a single institution.

METHODS:
A retrospective review was performed on 44 consecutive pediatric patients with spinal deformity in which 138 pedicle screws were used from Jan 1987 to Mar of 1998. There were 26 females and 18 males, with an average age of 15.3 yrs at the time of surgery. The diagnoses were: adolescent idiopathic scoliosis (AIS) – 18 patients, neuromuscular scoliosis or kvphoscoliosis–7, Scheuermann's kyphosis–6, revision surgery–5, spondylolisthesis–2, miscellaneous –6. Pedicle screws were placed utilizing two techniques: the free hand technique in which anatomic landmarks were used to guide the surgeon followed by radiographic confirmation – 119 screws; and the fluoroscopically–guided technique in which the initial guide pin is advanced into the pedicle directly under image intensification – 17 screws. All screws were placed by pediatric orthopaedic surgeons at a single institution. The average follow–up was 37 months (range 24 to 62 months) from the last surgery.

RESULTS:
The number of screw placed at each level was:

The use of pedicle screws increased during the study period: 1987 to 1990: 3 patients (6 screws); 1991 to 1995: 15 patients (46 screws); 1996 to Mar 1998: 26 patients (86 screws) Fifteen of 138 (11%) screws were removed in 5 patients because of complications. However, only 1 was removed because of a direct complication from placement of the screw in a patient who had migration of the L3 screw at the time of rod rotation for AIS without neurologic injury or long–term complication. Four additional patients had screw removal for complications unrelated to the screws: infection (3 screws), pseudoarthrosis following revision surgery for congenital scoliosis (8 screws), disengagement of the rod from the screw (1 screw) and painful hardware (2 screws). There were no neurologic complications in any patient. CONCLUSIONS: The incidence of screw removal directly related to pedicle screw placement was 0.7% (1/138) without neurologic complication. Pedicle screws can be safely placed to treat spinal deformity in a pediatric center with results comparable to previous reports. A clear understanding of the anatomy is essential in the placement of pedicle screws to prevent complications and achieve good results.