Todd F. Ritzman

A prospective comparison of computer-navigated and fluoroscopic-guided in situ fixation of slipped capital femoral epiphysis.

Background: Slipped capital femoral epiphysis (SCFE) is usually treated with percutaneous in situ screw fixation to prevent further progression of deformity. The purpose of this investigation is to compare computer navigation (CN) techniques with traditional fluoroscopic (fluoro) techniques for in situ fixation of SCFE. Methods: This study was an IRB-approved prospective study of 39 hip pinnings in 33 children. CN techniques were used in 22 cases and fluoro in 17. The CN and fluoro groups were statistically similar in terms of grade and acuity of the slip. Children were assigned to the groups based on the intraoperative imaging technique used by the attending on call, with 3 surgeons in each group taking equal amounts of call. The “approach-withdraw” technique was used in all cases. Postoperative limited-cut, reduced-dose computed tomography (CT) scans were obtained to evaluate screw placement. This included blinded analysis for screw penetration of the joint, screw tip-to-apex distance, the distance the screw passed to the center of the physis, and attainment of center-center position. The number of pin passes, intraoperative radiation exposure, and operating room (OR) time were also analyzed. Statistics used included ANOVA, the &khgr;2 and median tests. Results: Compared with the fluoro group, CN resulted in more accurate screw placement. There was 1 case of joint penetration in the fluoro group not appreciated intraoperatively but detected on postoperative CT. CN also resulted in statistically significant (P<0.05) reduced screw tip-to-apex distance and distance to the center of the physis. There was no statistically significant difference between the 2 groups in attainment of the center-center position, number of pin passes, or intraoperative radiation exposure. OR time averaged 19 minutes longer in the CN group. There was no case of avascular necrosis or chondrolysis in either of the groups. Conclusions: Compared with traditional fluoro techniques, CN in situ fixation of SCFE results in more accurate screw placement, comparable number of pin passes and intraoperative radiation exposure, and increased OR time. The cost-benefit ratio of this technology requires careful consideration at each individual institution. Level of Evidence: II.

The effects of hypothyroidism on the proximal femoral physis in miniature swine

As a potential means of comparing hypothyroidism in humans, this work intended to establish a defined hypothyroid state in immature miniature swine and evaluate specific molecular, cellular, and extracellular responses of their growth plates. Two male, 11‐week‐old Sinclair miniature swine were given 6‐propyl‐2‐thiouracil (PTU) in their water and two other like animals (controls) were provided water without PTU. Blood levels of thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxin (T4) were monitored weekly. At 25 weeks of age, the hind limb proximal femoral physes were harvested and divided into portions for histology and reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR) analysis. Compared to controls, swine administered PTU exhibited increased TSH and decreased T3 and T4 serum levels during the study period, features consistent with a hypothyroid state. Compared to controls, hypothyroid swine exhibited structurally altered physes and demonstrated significantly decreased gene expression of aggrecan (p < 0.05) and type X collagen (p ≤ 0.1). This is the first hypothyroid model established in miniature swine and represents a potentially important advance for understanding the condition in humans, in which, like this swine model, there are changes critical to growth plate molecular biology, biochemistry and structure.

Evaluation of Limited Screw Density Pedicle Screw Constructs in Posterior Fusions for Adolescent Idiopathic Scoliosis

STUDY DESIGN Retrospective case series. OBJECTIVES To compare radiographic and clinical outcomes in posterior spine fusions with pedicle screw instrumentation of varying screw densities in the treatment of adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA Posterior spinal fusion with pedicle screw instrumentation is the mainstay of surgical treatment for AIS. The most commonly used construct consists of screws placed at every level on the concave side of the deformity and nearly every level on the convex side. However, some surgeons have begun using constructs with fewer pedicle screws. The literature comparing outcomes of these differing pedicle screw constructs is limited. METHODS Fifty-two consecutive cases of posterior spinal fusions for AIS performed by four surgeons were reviewed. High screw density constructs were used in 26 cases and limited screw density constructs in 26 cases. Construct characteristics and radiographic measurements were compared preoperatively and at last follow-up. Operative time and estimated costs were also evaluated. Student t tests were used to compare the groups with p < .05 considered significant. RESULTS There was no significant difference in magnitude of correction for the high versus limited screw density group initially (38.5° vs. 34.9°, p = .093) or at final follow-up (36.9° vs. 32.2°, p = .054). Sagittal alignment, coronal balance, and translation of the major apical vertebra were comparable and stable in both groups. The high versus limited screw density group utilized significantly more pedicle screws (16.8 vs. 11.6 screws, p < .0001), had longer operative times (309 vs. 267 minutes, p = .007), and had additional estimated direct costs of

Transphyseal Fracture of the Distal Humerus

5,800. CONCLUSIONS Excellent curve correction, stability, and balance can be achieved using fewer screws than commonly used in posterior pedicle screw fusions for AIS. Operative time is reduced, and risk and cost are decreased with the use of limited screw density constructs. LEVEL OF EVIDENCE III.

Perioperative Safety: Keeping Our Children Safe in the Operating Room

Transphyseal fractures of the distal humerus typically occur in children younger than 3 years secondary to birth trauma, nonaccidental trauma, or a fall from a small height. Prompt and accurate diagnosis of the injury is crucial for a successful outcome. Recognizing that the forearm is not aligned with the humerus on plain radiography can aid in the diagnosis of the injury. Surgical management is most commonly performed with the aid of an arthrogram. Closed reduction and percutaneous pinning techniques similar to those used for supracondylar humerus fractures are employed. The most common complication is cubitus varus caused by a malunion, osteonecrosis of the medial condyle, or growth arrest. A corrective lateral closing wedge osteotomy can be performed to restore a nearly normal carrying angle.

Noninvasive device for adjusting fastener

The entire operating room team is responsible for the safety of children in the operating room. As a leader in the operating room, the surgeon is impactful in ensuring that all team members are committed to providing this safe environment. This is achieved by the use of perioperative huddles or briefings, the use of appropriate surgical checklists, operating room standardization, surgeons proficient in the care they provide, and team members that embrace Just Culture.