The results after treatment of fifty-two lumbar and thoracolumbar fractures with Cotrel-Dubousset instrumentation were reviewed as part of an ongoing study. Nineteen patients (average duration of follow-up, fifteen months) had been managed with short-segment pedicle-screw instrumentation. This preliminary report outlines the complications and pitfalls identified during the initial healing phase in this subgroup of patients. There were no neurological or vascular injuries due to placement of the pedicle screws, but ten patients had some form of failure of the fixation during the early period of healing. Failure of the fixation was manifested in three ways: progressive kyphosis secondary to the bending of screws (six patients), kyphosis secondary to osseous collapse or vertebral translation without bending of the hardware (three patients), and segmental kyphosis after a caudad screw in the lumbar construct broke (one patient, who had had a combined instrumentation for multiple fractures). Untreated anterior instability, and pre-stressing of the screws when the rods were contoured in situ, resulted in a high rate of failure. The high rate of failure of the hardware associated with this fixation construct suggests that posterior screw fixation alone may not be adequate when Cotrel-Dubousset instrumentation is used for short-segment lumbar arthrodeses. Bent screws or measurable kyphosis did not always herald a clinical failure, but patients who had progressive kyphosis of more than 10 degrees had substantially more pain than did those who had little or no progression. The results reported here are preliminary, and speculation as to the importance of these findings and as to the long-term outcome in these patients would be premature.(ABSTRACT TRUNCATED AT 250 WORDS)

Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. A preliminary report.

Pedicle screws have dramatically improved the outcomes of spinal reconstruction requiring spinal fusion. Short-segment surgical treatments based on the use of pedicle screws for the treatment of neoplastic, developmental, congenital, traumatic, and degenerative conditions have been proved to be practical, safe, and effective. The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine. Carefully applied pedicle-screw fixation does not produce severe or frequent complications. Pedicle-screw fixation can be effectively and safely used wherever a vertebral pedicle can accommodate a pedicle screw--that is, in the cervical, thoracic, or lumbar spine. Training in pedicle-screw application should be standard in orthopaedic training programs since pedicle-screw fixation represents the so-called gold standard of spinal internal fixation.

The use of pedicle-screw internal fixation for the operative treatment of spinal disorders.

STUDY DESIGN: The authors undertook a three-part study to better understand the impact of perioperative nutritional status on postoperative complications in patients undergoing spinal surgery. In preliminary Parts I and II, the authors targeted two groups of patients who are particularly nutritionally challenged. In Part III, they studied a large group of consecutive patients undergoing routine lumbar spinal fusion. OBJECTIVES: To determine whether preoperative nutritional status was a significant predictor of postoperative complications in patients undergoing elective lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: In Part I, 27 patients treated surgically for vertebral osteomyelitis were divided into two groups based on their preoperative nutritional status. Twenty-four of the 26 postoperative complications were in the malnourished group (P < 0.001). In Part II, 15 (75%) of 20 patients treated surgically for spinal cord injury were found to become malnourished in the postoperative period. Seventeen complications were noted, all in the malnourished group (P = 0.001). METHODS: One hundred fourteen consecutive patients undergoing selective lumbar decompression and fusion were identified and their records reviewed. In addition to preoperative nutritional status, data gathered included age, sex, height, weight, past medical history, steroid use, alcohol use, tobacco use, type of bone graft (allograft vs. autograft), history of previous lumbar surgery, number of levels fused, and use of spinal instrumentation. RESULTS: Eleven of 13 postoperative infectious complications (10 deep wound infections) were noted in the malnourished group (P < 0.001). By stepwise logistic regression analysis, preoperative nutritional status was an extremely significant independent predictor of postoperative complications in patients undergoing elective lumbar spinal fusion (P = 0.0018). CONCLUSIONS: The prevalence data in our study population suggest that a large number (25%) of patients undergoing elective lumbar spine surgery are nourished inadequately at surgery. This number is higher (42%) in older patients. The authors recommend that close attention be paid to the perioperative nutritional status of patients undergoing lumbar spinal surgery. Patients with suboptimal nutritional parameters should be supplemented and replenished before elective surgery.

Perioperative nutrition and postoperative complications in patients undergoing spinal surgery.

BACKGROUND: Improved understanding of rod fracture (RF) in adult spinal deformity could be valuable for implant design, surgical planning, and patient counseling. OBJECTIVE: To evaluate symptomatic RF after posterior instrumented fusion for adult spinal deformity. METHODS: A multicenter, retrospective review of RF in adult spinal deformity was performed. Inclusion criteria were spinal deformity, age older than 18 years, and more than 5 levels posterior instrumented fusion. Rod failures were divided into early (#12 months) and late (.12 months). RESULTS: Of 442 patients, 6.8% had symptomatic RF. RF rates were 8.6% for titanium alloy, 7.4% for stainless steel, and 2.7% for cobalt chromium. RF incidence after pedicle subtraction osteotomy (PSO) was 15.8%. Among patients with a PSO and RF, 89% had RF at or adjacent to the PSO. Mean time to early RF (63%) was 6.4 months (range, 2-12 months). Mean time to late RF (37%) was 31.8 months (range, 14-73 months). The majority of RFs after PSO (71%) were early (mean, 10 months). Among RF cases, mean sagittal vertical axis improved from preoperative (163 mm) to postoperative (76.9 mm) measures (P , .001); however, 16 had postoperative malalignment (sagittal vertical axis .50 mm; mean, 109 mm). CONCLUSION: Symptomatic RF occurred in 6.8% of adult spinal deformity cases and in 15.8% of PSO patients. The rate of RF was lower with cobalt chromium than with titanium alloy or stainless steel. Early failure was most common after PSO and favored the PSO site, suggesting that RF may be caused by stress at the PSO site. Postoperative sagittal malalignment may increase the risk of RF.

Assessment of Symptomatic Rod Fracture After Posterior Instrumented Fusion for Adult Spinal Deformity

Object Improved understanding of rod fracture (RF) following adult spinal deformity (ASD) surgery could prove valuable for surgical planning, patient counseling, and implant design. The objective of this study was to prospectively assess the rates of and risk factors for RF following surgery for ASD. Methods This was a prospective, multicenter, consecutive series. Inclusion criteria were ASD, age > 18 years, ≥5 levels posterior instrumented fusion, baseline full-length standing spine radiographs, and either development of RF or full-length standing spine radiographs obtained at least 1 year after surgery that demonstrated lack of RF. ASD was defined as presence of at least one of the following: coronal Cobb angle ≥20°, sagittal vertical axis (SVA) ≥5 cm, pelvic tilt (PT) ≥25°, and thoracic kyphosis ≥60°. Results Of 287 patients who otherwise met inclusion criteria, 200 (70%) either demonstrated RF or had radiographic imaging obtained at a minimum of 1 year after surgery showing lack of RF. The patients' m...

Prospective multicenter assessment of risk factors for rod fracture following surgery for adult spinal deformity

Mechanical consequences of rod contouring and residual scoliosis in sublaminar segmental instrumentation

Fifty-two nonambulatory totally-involved cerebral palsy patients with spinal deformity who had barium swallow examinations of their gastroesophageal tract as part of their preoperative evaluation were retrospectively reviewed. Thirty-six patients (69%) were identified with abnormalities of their swallowing mechanism. Subnormal nutritional indices were identified as well in 41 patients (79%). Ten of 38 patients undergoing spinal surgery developed significant postoperative complications. Nine of the 10 complications occurred in patients in whom gastroesophageal or nutritional abnormalities were identified but not addressed before spinal surgery. We recommend gastroesophageal and nutritional evaluation of all patients with cerebral palsy before spinal surgery.

Andrew G. S. King

Papers

Mechanical consequences of rod contouring and residual scoliosis in sublaminar segmental instrumentation

Gastroesophageal evaluation in totally involved cerebral palsy patients