Craig P. Eberson

EFFECT OF LOW-INTENSITY ULTRASOUND STIMULATION ON CONSOLIDATION OF THE REGENERATE ZONE IN A RAT MODEL OF DISTRACTION OSTEOGENESIS

This study was performed to explore the tissue-level changes in mineralization caused by low-intensity ultrasound stimulation after distraction osteogenesis. Unilateral femoral lengthenings (7 mm) were performed on 34 male Sprague-Dawley rats. Half of the animals received daily ultrasound stimulation for 5 weeks; the remaining animals received sham treatments. Healing was assessed with serial radiographs, quantitative micro-computed tomography, and biomechanical testing. Twenty-one animals were evaluated at the conclusion of the study (9 experimental, 12 control). Radiographically, healing of the ultrasound-treated bones preceded that of the sham-treated bones by approximately 1 week. Bone volume fraction and trabecular bone pattern factor were significantly higher in the ultrasound-treated animals, but there were no significant differences in bone mineral content or bone mineral density. The ultrasound-treated femurs were 20% stiffer and 33% stronger than the control femurs, but the differences were not statistically significant. These findings suggest that pulsed, low-intensity ultrasound matures the regenerate by altering the microarchitecture of the newly formed bone.

The role of ketorolac in decreasing length of stay, and narcotic complications in the postoperative pediatric orthopaedic patient

The control of postoperative pain in the pediatric orthopaedic patient is a challenging endeavor. Several studies have shown the efficacy of ketorolac tromethamine in the pediatric general surgical population, but its efficacy in the pediatric orthopaedic population remains unproven. Twenty-seven consecutive patients (age 6 months to 18 years) who underwent long-bone osteotomies or foot procedures by a group of three pediatric orthopaedic surgeons were given a ketorolac protocol (1 mg/kg loading, 0.5 mg/kg every 6 h for 24 h). Breakthrough pain was managed with morphine until the patient was able to take oral pain medication, as was any pain after the 24-h period for ketorolac expired. Thirty-seven age- and case-matched patients were used as retrospective controls. The patients in the study who received ketorolac required significantly fewer doses of morphine than did the control group (2.29 +/- 3.98 vs. 10.02 +/- 3.39; p < 0.05). In addition the patients on the ketorolac protocol experienced fewer gastrointestinal side effects (4% vs. 32%; p < 0.05). Finally, the patients in the ketorolac group had a significantly shorter length of stay (3.63 +/- 1.64 days vs. 4.74 +/- 1.76 days; p < 0.05). There were no bleeding complications in either group. Ketorolac is thus a safe and effective means of controlling postoperative pain in the pediatric orthopaedic population while avoiding the troubling maleffects seen with the exclusive use of morphine.

Biomechanical Analysis of Suture Bridge Fixation for Tibial Eminence Fractures

PURPOSEnTo perform a biomechanical analysis of suture bridge fixation for tibial eminence fractures using PushLock anchors (Arthrex, Naples, FL) and compare it with traditional suture fixation and screw fixation.nnnMETHODSnThis study used 24 porcine knees, divided into 3 comparison fixation groups: PushLock suture bridge fixation, screw fixation, and suture fixation. Each knee was dissected of all soft tissue, leaving only the anterior cruciate ligament. A tibial eminence fracture was created with disruption of the posterior hinge, and each knee was fixed with a randomly assigned fixation technique. After fixation, each knee underwent 2 phases of biomechanical testing. The initial cyclic dynamic phase assessed the displacement change after 200 cycles (in millimeters) and initial stiffness (in Newtons per millimeter) of the fixation construct. After completion of dynamic testing, each specimen underwent a single tensile failure test load to assess ultimate failure load (in Newtons) and displacement (in millimeters) to ultimate failure.nnnRESULTSnThere was a significant difference for the load-to-failure outcome variable among treatment groups (P = .004 by analysis of variance, 1 - β = 0.851). Mean ultimate failure load borne by the PushLock fixation group was statistically significantly higher in comparison with the screw (P = .007) and suture (P = .017) fixation groups. For the cyclical testing, the primary outcome variable of displacement change after 200 loading cycles failed to show a significant difference among the 3 groups (P = .412).nnnCONCLUSIONSnSuture bridge fixation with PushLock anchors is a new and effective surgical technique for the treatment of displaced tibial eminence fractures. By use of a high-bone density animal model, our results suggest that this suture bridge construct provides superior fixation with regard to ultimate failure load compared with standard screw fixation and suture fixation.nnnCLINICAL RELEVANCEnThe suture bridge technique provides another fixation option for displaced tibial eminence fractures with comparable, and in some instances superior, biomechanical properties to screw fixation and suture fixation.

Contralateral Intrathoracic Displacement of the Humeral Head. A Case Report

Fracture-dislocation of the proximal aspect of the humerus with remote displacement of the humeral head is exceedingly rare. We are aware of five reports that describe such injuries2,3,5,7,8. In four of them, the injury was an ipsilateral intrathoracic displacement of the humeral head resulting from fracture-dislocation. The fifth, more recent report details a case in which the displaced humeral head was found in the ipsilateral retroperitoneal space8.nnWe report a case of a four-part fracture-dislocation of the proximal aspect of the humerus with displacement of the humeral head into the contralateral pleural cavity.nnA sixty-four-year-old, right-hand-dominant man fell fifteen feet (4.6 meters) from a ladder while repairing a skylight in his home. He was transported to our level-1 trauma center, where he was evaluated according to Advanced Trauma Life Support protocols1. When he arrived, he was alert and hemodynamically stable and he reported pain in the chest and left shoulder. There was extensive subcutaneous emphysema over both hemithoraces, and the posterior aspects of the ribs were tender bilaterally. The trachea was in the midline, and breath sounds were diminished bilaterally. A radiograph of the chest confirmed bilateral pneumothoraces, and chest tubes were placed.nnThere was diffuse swelling about the left shoulder girdle. The skin was intact. The left radial pulse was intact, and the pulses on the left and right sides were symmetrical. On neurological examination, there was diminished sensibility to light touch in the axillary nerve distribution and weakness of the deltoid, biceps, and triceps on the left side. Although the examination was limited because the patient had pain and had been sedated, it was possible to palpate the biceps and triceps contracting. Contraction of the deltoid was felt by some examiners but not by …

Pediatric orthopaedic practice management: The role of midlevel providers

The efficient functioning of a pediatric orthopaedic office practice is subject to many variables. Determining the number and nature of care providers is a challenging problem and unique to each practice. The threshold to hire new or additional personnel will depend on the core practitioners’ perception of practice satisfaction and patient mix. The number of operative pediatric orthopaedic surgeons necessary in a practice, as well as how many nonoperative care providers, is related to many different practice characteristics. Hiring additional surgeons to provide nonoperative patient care may be neither feasible nor possible. Personal decisions regarding the surgeons’ lifestyle and compensation requirements will impact decisions regarding the chosen provider mix. A well-run office should be efficient and comfortable for both patients and staff, have sufficient ancillary support, and be financially sound. The composition of this office will vary, depending on practice location and size. There are several different types of employees who combine as a team to run an office practice. In many circumstances, a practice may experience a marginally increased demand on its outpatient services, but this demand may not be enough to justify the increased capacity and financial overhead associated with hiring an additional pediatric orthopaedic surgeon. In other circumstances, the practice may experience a large increase in office work, but surgical volume may not keep pace, creating a practice opportunity that is not appealing to a pediatric orthopaedic surgeon desiring a heavy surgical load. Physiatrists and pediatricians with specialized musculoskeletal training may fill this void, but there are downsides to the incorporation of these individuals into pediatric orthopaedic practices. This article covers some of these concerns. The use of midlevel providers (MLPs), specifically nurse practitioners (NP) and physician assistants (PAs), functioning as physician extenders has become increasingly popular in all medical and surgical fields. The large volume of office pediatric orthopaedic work, frequently uncomplicated musculoskeletal complaints, lends itself well to the use of MLPs. This article reviews the use of MLPs in today’s pediatric orthopaedic practice setting.

Spinal Deformity and Athletics

Exercise and athletic competition for the young individual has become increasingly more important in society. Scoliosis and Scheurmann kyphosis are spinal deformities prevalent in up to 2% to 3% and 7% of the population respectively, requiring nonoperative and occasionally operative treatment. Curve progression and patient physiologic age dictate treatment regimens. Bracing and physical therapy is the mainstay for nonoperative treatment, whereas soft tissue releases and fusion with instrumentation are used for operative correction. Athletic activity and sports participation is usually allowed for patients undergoing nonoperative treatment. Return to sport after surgical correction is variable, often decided by the treating surgeon, and based on the level of fusion and sporting activity. Although most treating surgeons promote some form of activity regardless of treatment modality chosen, caution should be taken when deciding on participation in collision activities such as football and wrestling.

Epiphysiodesis with infusion of stromal cell-derived factor-1 in rabbit growth plates.

BACKGROUNDnThe mechanism of physeal closure is poorly understood, although both mechanical and biological factors may play a role in the process. In this study, we evaluated the effect of the application of a chemokine stromal cell-derived factor-1 (SDF-1) to rabbit physes in vivo with regard to growth inhibition.nnnMETHODSnA continuous infusion system consisting of a fenestrated catheter and an osmotic pump were implanted into the right proximal tibial physis of twenty six-week-old New Zealand White rabbits. Ten of the pumps were loaded with human recombinant SDF-1alpha, and ten were loaded with phosphate-buffered saline solution (sham treatment). The left leg was used as the uninvolved control. The growth of the tibiae was followed radiographically for eight weeks, and histologic analysis was performed for both the SDF-1-treated rabbits and the sham-treated rabbits at two, four, and eight-week time-points.nnnRESULTSnRadiographic evaluation showed a significant growth inhibition in the SDF-1alpha-treated physes (4.5 +/- 3.0 mm; p = 0.007) compared with the sham-treated physes after eight weeks. No difference was noted when the sham-treated leg was compared with the contralateral, control leg (0.2 +/- 2.9 mm; p = 0.465). Histologic evaluation showed marked physeal disorganization, narrowing, and proteoglycan loss and a significant decrease in physeal height (p < 0.0001) for the SDF-1-treated group. Reversible growth slowing was noted in the uninvolved, control leg of the SDF-1-treated group at six weeks, with resolution of the difference by eight weeks.nnnCONCLUSIONSnSDF-1 may be used to induce physeal closure through a targeted infusion system. However, transient systemic effects of SDF-1 may exist and must be evaluated further prior to its clinical use for epiphysiodesis.

Predictors of failure of nonoperative treatment for type-2 supracondylar humerus fractures.

Background Closed reduction and casting for type-2 supracondylar fractures is a viable treatment option, but studies have shown that some patients will fail to maintain the initial reduction in a cast. This study sought to identify predictors of failed treatment of closed reduction and casting for these fractures. Methods We performed a retrospective case-control study of type-2 supracondylar fractures treated by closed reduction and casting. Using radiographic failure of reduction as our primary outcome measure, we examined injury, postreduction, and follow-up films evaluating the anterior humeral line, cast flexion angle, and degree of cast padding in an attempt to identify predictors of failure. Results We reviewed 645 fractures. Of 126 type-2 fractures, 61 fractures were included in the study. There were 49 (80%) nonoperative treatment successes and 12 failures (20%) with an average follow-up of 41 days (range, 20 to 161 d). We found that (1) the degree of fracture extension using an index based on the anterior humeral line on the injury film was significantly related to failure of cast treatment (P=<0.01), and (2) the width of the soft tissue shadow of the upper arm on the postreduction film was of borderline significance (P=0.02). Cast flexion angle and cast padding were not predictive of radiographic loss of reduction (P=0.94 and 0.70). Conclusions Despite adequate reduction and casting of type-2 supracondylar fractures, some fractures will lose reduction and require delayed pinning. The degree of extension of the distal fragment at the time of injury may help to predict the likelihood of failure of nonoperative treatment. Level of Evidence III.

Delayed Presentation of a Brachial Artery Pseudoaneurysm After a Supracondylar Humerus Fracture in a 6-year-old Boy: A Case Report

Supracondylar fractures of the humerus are the most common elbow fractures in children, accounting for 60% to 70% of all pediatric elbow fractures. These fractures often have neurovascular complications because of deformity and the sharp nature of the fracture fragments. The management of patients who present with diminished or absent pulses, but a well-perfused extremity is a topic of debate. Between 3% and 14% of patients present with an altered vascular examination and a consistent treatment logarithm has not been proposed in the literature. To our knowledge, a brachial artery pseudoaneurysm presenting in a delayed fashion in the setting of a normal vascular examination has not been reported. We report a 6-year-old boy who had a delayed presentation of a brachial artery pseudoaneurysm after a supracondylar humerus fracture, which was repaired with a saphenous vein graft. This is to emphasize close neurological and vascular monitoring even in the setting of a well-perfused hand. In addition, this would suggest that closer postoperative evaluation in significantly displaced fractures should be performed, even beyond the fracture healing stage.

Idiopathic Chondrolysis Treated With Etanercept

Idiopathic chondrolysis of the hip in children has been well documented in the literature. The insidious nature of the symptoms and lack of early radiographic findings and diagnostic testing often delay diagnosis. Children often report a stiff, painful hip and have an associated limp in the absence of trauma or constitutional symptoms. Despite these symptoms it remains a poorly understood diagnosis with no identifiable cause. Some have speculated an inflammatory cause, as this disease exhibits joint space narrowing, presumably due to enzymatic activity similar to juvenile rheumatoid arthritis. Despite case reports attempting traction, physical therapy, nonsteroidal anti-inflammatories, steroids, and even operative intervention, no current treatment regimen exists that offers proven appreciable benefit. We hypothesized the powerful anti-inflammatory properties of etanercept would provide symptomatic and radiographic improvement of idiopathic chondrolysis of the hip. This article presents a case of an adolescent boy with a stiff, painful left hip that failed treatment with traction, physical therapy, naproxen, and methotrexate, prior to initiating etanercept. After 1 year of daily etanercept therapy, the patients hip motion improved in all directions and his pain completely resolved. This novel therapeutic approach offered symptomatic relief and radiographic improvement, and may provide an effective treatment strategy for this difficult disease.