Level of Experience Does Not Influence the Accuracy of Radiographic and Ultrasound Measurements of Magnetically Controlled Growing Rod Distractions.

BACKGROUND: Magnetically controlled growing rods (MCGR) have become a popular surgical option for the treatment of early-onset scoliosis. Both radiographs and ultrasound are currently used to measure the amount of length achieved when MCGRs are distracted. Previous studies have investigated the intraobserver and interobserver reliability of radiographic and ultrasound measurements of MCGR distraction. Some authors have reported that there is a "learning curve" in measuring MCGR lengthening with ultrasound, suggesting that new users require several months of experience before they can accurately perform the measurements. The goal of this study was to determine whether surgical experience of the rater is associated with the accuracy of radiographic and ultrasound measurements of MCGR distraction. METHODS: Six raters evaluated 29 deidentified radiographs and 30 ultrasound images from early-onset scoliosis patients with MCGR. Raters had varying levels of experience, ranging from a senior fellowship-trained pediatric orthopaedic surgeon to a junior orthopaedic surgery resident. Raters measured the amount of rod distraction in 2 sessions spaced 2 weeks apart. All raters were provided with a document demonstrating the radiographic and ultrasound measurement techniques before the first round of measurements. Intraclass correlation coefficients were calculated. RESULTS: Excellent intraobserver and interobserver agreement was achieved for both radiographic and ultrasound measurements of MCGR distraction. Subanalysis based on experience level showed that excellent intraobserver agreement was maintained with no evidence of decreased reliability in raters with less experience. CONCLUSIONS: Excellent intraobserver and interobserver agreement was obtained with radiographic and ultrasound measurements of MCGR distraction, regardless of the experience level of the rater. Posting a document with the radiographic and ultrasound measurement techniques in the orthopaedic surgery clinic, and perhaps also the radiology reading room may help avoid inaccurate measurements of distraction length secondary to a learning curve. LEVEL OF EVIDENCE: Level III-diagnostic.

Validation of Different Combination of Three Reversing Half-Hitches Alternating Posts (RHAPs) Effects on Arthroscopic Knot Integrity.

INTRODUCTION: With arthroscopic techniques being used, the importance of knot tying has been examined. Previous literature has examined the use of reversing half-hitches on alternating posts (RHAPs) on knot security. Separately, there has been research regarding different suture materials commonly used in the operating room. The specific aim of this study was to validate the effect of different stacked half-hitch configuration and different braided suture materials on arthroscopic knot integrity. METHODS: Three different suture materials tied with five different RHAPs in arthroscopic knots were compared. A single load-to-failure test was performed and the mean ultimate clinical failure load was obtained. RESULTS: Significant knot holding strength improvement was found when one half-hitch was reversed as compared to baseline knot. When two of the half-hitches were reversed, there was a greater improvement with all knots having a mean ultimate clinical failure load greater than 150 newtons (N). Comparison of the suture materials demonstrated a higher mean ultimate clinical failure load when Force Fiber® was used and at least one half-hitch was reversed. Knots tied with either Force Fiber® or Orthocord® showed 0% chance of knot slippage while knots tied with FiberWire® or braided fishing line had about 10 and 30% knot slippage chances, respectively. CONCLUSIONS: A significant effect was observed in regards to both stacked half-hitch configuration and suture materials used on knot loop and knot security. Caution should be used with tying three RHAPs in arthroscopic surgery, particularly with a standard knot pusher and arthroscopic cannulas. The findings of this study indicated the importance of three RHAPs in performing arthroscopic knot tying and provided evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons, thereby leading to better surgical outcomes in the future.