Why Irrigate for the Same Contamination Rate: Wound Contamination in Pediatric Spinal Surgery Using Betadine Versus Saline.

BACKGROUND: The risk of surgical site infection in pediatric posterior spine fusion (PSF) is up to 4.3% in idiopathic populations and 24% in patients with neuromuscular disease. Twenty-three percent of pediatric PSF tissue cultures are positive before closure, with a higher rate in neuromuscular patients. Our primary aim was to evaluate the feasibility of a complete randomized controlled trial to study the efficacy of surgical site irrigation with povidone-iodine (PVP-I) compared with sterile saline (SS) to reduce the bacterial contamination rate before closure in children undergoing PSF. METHODS: One hundred seventy-five subjects undergoing PSF were enrolled in a multicenter, single-blind, pilot randomized controlled trial. We recruited patients at low-risk (LR) and high-risk (HR) for infection 3:1, respectively. Before closure, a wound culture was collected. Nonviable tissues were debrided and the wound was soaked with 0.35% PVP-I or SS for 3 minutes. The wound was then irrigated with 2 L of saline and a second sample was collected. RESULTS: One hundred fifty-three subjects completed the protocol. Seventy-seven subjects were allocated to PVP-I (18 HR, 59 LR) and 76 to SS (19 HR, 57 LR). Cultures were positive in 18% (14/77) of PVP-I samples (2 HR, 12 LR) and in 17% (13/76) of SS samples (3 HR, 10 LR) preirrigation and in 16% (12/77) of PVP-I samples (5 HR, 7 LR) and in 18% (14/76) of SS samples (4 HR, 10 LR) postirrigation. Eight percent (3/37) HR subjects (1 PVP-I, 2 SS) experienced infection at 30 days postoperative. No LR subjects experienced infection. CONCLUSIONS: Positive cultures were similar across treatment and risk groups. The bacterial contamination of wounds before closure remains high regardless of irrigation type. A complete randomized controlled trial would be challenging to adequately power given the similarity of tissue positivity across groups. LEVEL OF EVIDENCE: Level II-pilot randomized controlled trial.

How does differential rod contouring contribute to 3-dimensional correction and affect the bone-screw forces in adolescent idiopathic scoliosis instrumentation?

BACKGROUND: Differential rod contouring is used to achieve 3-dimensional correction in adolescent idiopathic scoliosis instrumentations. How vertebral rotation correction is correlated with the amount of differential rod contouring is still unknown; too aggressive differential rod contouring may increase the risk of bone-screw connection failure. The objective was to assess the 3-dimensional correction and bone-screw forces using various configurations of differential rod contouring. METHODS: Computerized patient-specific biomechanical models of 10 AIS cases were used to simulate AIS instrumentations using various configurations of differential rod contouring. The tested concave/convex rod configurations were 5.5/5.5 and 6.0/5.5mm diameter Cobalt-chrome rods with contouring angles of 35°/15°, 55°/15°, 75°/15°, and 85°/15°, respectively. 3-dimensional corrections and bone-screw forces were computed and analyzed. FINDINGS: Increasing the difference between the concave and convex rod contouring angles from 25° to 60°, the apical vertebral rotation correction increased from 35% (SD 17%) to 68% (SD 24%), the coronal plane correction changed from 76% (SD 10%) to 72% (SD 12%), the thoracic kyphosis creation from 27% (SD 60%) to 144% (SD 132%), and screw pullout forces from 94N (SD 68N) to 252N (SD 159N). Increasing the concave rod diameter to 6mm resulted in increased transverse and coronal plane corrections, higher thoracic kyphosis, and screw pullout forces. INTERPRETATIONS: Increasing the concave rod contouring angle and diameter with respect to the convex rod improved the transverse plane correction but with significant increase of screw pullout forces and thoracic kyphosis. Rod contouring should be planned by also taking into account the 3-dimensional nature and stiffness of the curves and combined with osteotomy procedures, which remains to be studied.

Cavus foot deformity in children.

A cavus deformity of the foot is easily recognizable, but appropriate neurologic assessment can help to determine the etiology. Cavovarus, the most frequent type of cavus foot, presents with an elevated medial longitudinal arch, first ray plantarflexion, and, if rigid, a fixed heel varus. Common causes include progressive motor sensory conditions, typically Charcot-Marie-Tooth disease, and nonprogressive conditions such as cerebral palsy and poliomyelitis. A calcaneocavus foot may be seen in poliomyelitis, spinal dysraphism, and peripheral neuropathy. Initially, the cavus deformity is flexible, but if left untreated, it becomes a fixed bony deformity. Physical examination should include the cavovarus block test, which assesses flexibility of the hindfoot deformity and can direct surgical treatment. Standing radiographs of the feet and spine, magnetic resonance imaging, and electrodiagnostic studies may be useful. Management goals are to obtain a plantigrade, mobile, pain-free, stable, motor-balanced foot. Surgical options include soft-tissue and plantar fascia releases for a flexible deformity, osteotomy for a fixed deformity, and tendon transfers to restore muscle balance. Triple arthrodesis has poor long-term results in patients with progressive deformity and sensory impairment.