Serum Titanium Levels Remain Elevated But Urine Titanium is Undetectable in Children With Early Onset Scoliosis Undergoing Growth-Friendly Surgical Treatment: A Prospective Study.

BACKGROUND: Elevated serum titanium levels have been found in patients with early onset scoliosis (EOS) treated with traditional growing rods (TGR), magnetically controlled growing rods (MCGR), and vertical expandable prosthetic titanium rib (VEPTR). No studies have investigated whether serum titanium remains persistently elevated and if titanium is excreted. Our purpose was to compare serum titanium levels in patients with EOS with growth-friendly instrumentation to age-matched controls and evaluate urine titanium and serial serum titanium levels in patients with EOS. METHODS: This was a prospective case-control study. Patients with EOS with TGR, MCGR, or VEPTR underwent urine titanium and serial serum titanium collection at a minimum 6-month interval. Control patients did not have a history of metal implant insertion and underwent serum titanium collection before fracture fixation. RESULTS: Twenty patients with EOS (6 TGR, 8 MCGR, and 6 VEPTR) and 12 controls were analyzed. The control group had no detectable serum titanium (0 ng/mL), whereas the patients with EOS had a median serum titanium of 4.0 ng/mL ( P < 0.001). Analysis of variance showed significantly higher median serum titanium levels in the MCGR and VEPTR groups than the TGR group at time point 1 (5.5 vs 6.0 vs 2.0 ng/mL, P = 0.01) and time point 2 (6.5 vs 7.5 vs 2.0 ng/mL, P < 0.001). Binary comparisons showed a significant difference in serum titanium level between TGR and MCGR (time point 1: P = 0.026, time point 2: P = 0.011) and TGR and VEPTR (time point 1: P = 0.035, time point 2: P = 0.003). However, there was no difference between MCGR and VEPTR (time point 1: P = 0.399, time point 2: P = 0.492) even though the VEPTR group had a longer duration of follow-up ( P = 0.001) and a greater number of lengthenings per patient at the first serum collection ( P = 0.016). No patients with EOS had detectable urine titanium. CONCLUSIONS: Patients with EOS treated with titanium alloy growth-friendly instrumentation had elevated serum titanium levels compared with age-matched controls that persisted over time with no evidence of renal excretion. Additional studies are necessary to assess for local and systemic accumulation of titanium and the significance of long-term exposure to titanium in growing children. LEVEL OF EVIDENCE: Level III, therapeutic.

Optogenetic-induced muscle loading leads to mechanical adaptation of the Achilles tendon enthesis in mice.

Skeletal shape depends on the transmission of contractile muscle forces from tendon to bone across the enthesis. Loss of muscle loading impairs enthesis development, yet little is known if and how the postnatal enthesis adapts to increased loading. Here, we studied adaptations in enthesis structure and function in response to increased loading, using optogenetically induced muscle contraction in young (i.e., growth) and adult (i.e., mature) mice. Daily bouts of unilateral optogenetic loading in young mice led to radial calcaneal expansion and warping. This also led to a weaker enthesis with increased collagen damage in young tendon and enthisis, with little change in adult mice. We then used RNA sequencing to identify the pathways associated with increased mechanical loading during growth. In tendon, we found enrichment of glycolysis, focal adhesion, and cell-matrix interactions. In bone, we found enrichment of inflammation and cell cycle. Together, we demonstrate the utility of optogenetic-induced muscle contraction to elicit in vivo adaptation of the enthesis.

Optogenetic-Induced Muscle Loading Leads to Mechanical Adaptation of the Achilles Tendon Enthesis in Mice.

The growth of the skeleton depends on the transmission of contractile muscle forces from tendon to bone across the extracellular matrix-rich enthesis. Loss of muscle loading leads to significant impairments in enthesis development. However, little is known about how the enthesis responds to increased loading during postnatal growth. To study the cellular and matrix adaptations of the enthesis in response to increased muscle loading, we used optogenetics to induce skeletal muscle contraction and unilaterally load the Achilles tendon and enthesis in young (i.e., during growth) and adult (i.e., mature) mice. In young mice, daily bouts of unilateral optogenetic loading led to expansion of the calcaneal apophysis and growth plate, as well as increased vascularization of the normally avascular enthesis. Daily loading bouts, delivered for 3 weeks, also led to a mechanically weaker enthesis with increased molecular-level accumulation of collagen damage in young mice. However, adult mice did not exhibit impaired mechanical properties or noticeable structural adaptations to the enthesis. We then focused on the transcriptional response of the young tendon and bone following optogenetic-induced loading. After 1 or 2 weeks of loading, we identified, in tendon, transcriptional activation of canonical pathways related to glucose metabolism (glycolysis) and inhibited pathways associated with cytoskeletal remodeling (e.g., RHOA and CREB signaling). In bone, we identified activation of inflammatory signaling (e.g., NFkB and STAT3 signaling) and inhibition of ERK/MAPK and PTEN signaling. Thus, we have demonstrated the utility of optogenetic-induced skeletal muscle contraction to elicit structural, functional, and molecular adaptation of the enthesis in vivo especially during growth.

Preoperative Patient Education and Smaller Prescription Quantity Reduce Opioid Use After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis: Results of a Prospective Study.

BACKGROUND: Most opioids prescribed postoperatively are unused. Leftover opioids are a major source of nonmedical opioid use among adolescents. Postoperative opioid use has also been associated with prescription quantity. Our purpose was to evaluate the effect of preoperative patient education and implementation of evidence-based prescribing guidelines on opioid use and pain level after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: AIS patients aged 10 to 17 years undergoing PSF were prospectively enrolled [postintervention cohort (POST-INT)]. Previous data on 77 patients showed median consumption of 29 doses of oxycodone after PSF [preintervention cohort (PRE-INT)]. All eligible patients during the study period were discharged with 30 doses of oxycodone and standard nonopioid analgesics. Only study participants received education on postoperative pain control. Demographics, radiographic/surgical data, pain level, and patient-reported outcomes were collected. Requests for opioid refills were documented. RESULTS: Forty-nine patients were enrolled. POST-INT was divided into low (L, ≤8 doses), average (AVE, 9-25), and high (H, >25) opioid use groups. Demographics, radiographic/surgical data, pain level, and patient-reported outcomes were similar between the groups. However, there was a difference in days of oxycodone use, doses consumed in the first week, and leftover doses ( P <0.001). Comparison to the PRE-INT L (≤16 doses), AVE (17 to 42), and high (H, >42) use groups showed that POST-INT L and AVE consumed less oxycodone (L: P =0.002; AVE: P <0.001). Also, the overall POST-INT cohort had fewer mean days of oxycodone use (5.6 vs. 8.9, P <0.001) and doses used in the first week (14 vs. 23, P <0.001) compared with the PRE-INT cohort. Subanalysis showed fewer study participants requested and received an opioid refill [3/49 patients (6%)] compared with eligible patients who declined to participate, withdrew, or missed enrollment [8/35 patients (23%)] ( P =0.045). CONCLUSIONS: Preoperative patient education and smaller prescription quantity successfully reduced opioid use while maintaining excellent pain control after PSF for AIS. Setting expectations regarding postoperative pain management is critical, as nonstudy participants were significantly more likely to request an opioid refill. LEVEL OF EVIDENCE: Level II-therapeutic.

Humeral Head Ossification Growth Prediction: Can This Method Be Reproduced?

BACKGROUND: Radiographically assessing skeletal maturity is of paramount importance to guide appropriate management for patients with adolescent idiopathic scoliosis. The reported advantages of the Humeral Head Ossification System (HHOS) are an even distribution around peak growth age (PGA), the presence of an optimal view of the humeral head in most scoliosis radiographs, and an interobserver and intraobserver reliability of 0.95 and 0.96, respectively. The goal of this study was to determine whether similar reliability could be achieved at an institution other than the one at which the HHOS was originally described. METHODS: Six raters used the HHOS to stage the humeral head on 30 deidentified posteroanterior spine radiographs. This process was repeated 2 weeks later. All raters were provided with a document demonstrating the radiographic parameters of each stage, as well as annotations to aid with classification. Intraclass coefficients were calculated. A secondary analysis was then performed grouping stages 1-2 as "pre-PGA" and 3-5 as "post-PGA." RESULTS: Fair to moderate interobserver and intraobserver reliability was achieved when determining each individual HHOS stage. This improved to good to excellent when the humeral was classified as pre-PGA or post-PGA. Subanalysis did not show any correlation between intraobserver reliability and level of orthopaedic experience. CONCLUSIONS: We found fair to moderate interobserver and intraobserver reliability with the HHOS and this was independent of level of orthopaedic experience. This is much lower than reported by the authors who developed the system, and suggests that the HHOS might not be as easy to incorporate into a scoliosis management algorithm as previously noted. The improved reliability achieved when staging the humeral head as pre-PGA or post-PGA might be the true benefit of this system. LEVEL OF EVIDENCE: Level III-diagnostic.

Advanced Containment With Triple Innominate Osteotomy in Legg-Calve-Perthes Disease: A Viable Option Even in Severe Cases.

BACKGROUND: Legg-Calve-Perthes disease (LCPD), in its severe form, remains a challenge. More recent classifications, particularly the modified Elizabethtown classification, have highlighted the chronologic stage of LCPD and its effect on surgical outcome. Hip severity and age of disease onset have also been shown to be powerful determinants of outcome. This study was performed to determine whether disease stage, disease severity, or patient age, are absolute indicators of whether a patient can benefit from surgical containment with triple innominate osteotomy (TIO). METHODS: All patients with LCPD treated with TIO between 1995 and 2011 were collected. Only those patients with a minimum of 2-year radiographic follow-up and no previous or concomitant femoral realignment surgery were included. Fifty-four patients (56 hips) met our inclusion criteria. The modified Elizabethtown classification was used to classify disease stage as early (

Are the Current Classifications and Radiographic Measurements for Trochlear Dysplasia Appropriate in the Skeletally Immature Patient?

BACKGROUND: The assessment and classification of trochlear dysplasia in pediatric patients has yet to be well documented or validated. PURPOSE: To examine several different measurements/classifications of trochlear dysplasia in skeletally immature patients to assess inter- and intraobserver reliability and to determine which best correlates with patellar instability. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Radiographs and magnetic resonance imaging (MRI) scans of 36 skeletally immature patients undergoing surgery for patellar instability were compared with 27 age-matched cohort patients who had similar imaging for an acute knee injury but no clinical evidence of patellar instability. Trochlear dysplasia was measured/classified using the radiographic and MRI Dejour classifications, the trochlear depth index (TDI), the lateral trochlear inclination (LTI), and the medial condyle trochlear offset (MCTO). Additionally, the tibial tubercle-trochlear groove (TT-TG) distance was calculated for all patients. Inter- and intraobserver reliability of each measurement, as well as the ability to discriminate patients with patellar instability, were evaluated. RESULTS: Inadequate radiographs prevented the radiographic Dejour classification from being assessed in 78% of cases. The MRI Dejour classification had the lowest inter- and intraobserver reliabilities (κ = 0.687 and 0.596, respectively); all other measurements were greater than 0.80. The TDI, LTI, and MCTO all significantly differentiated patients with patellar instability compared with those with no instability, with critical cutoffs of 3 mm, 17°, and 1 mm, respectively. Patients with a TDI <3 mm or MCTO <1 mm were 33 and 38 times more likely to have patellar instability, respectively. The TT-TG was directly correlated with trochlear dysplasia severity. CONCLUSION: Trochlear dysplasia is common in skeletally immature patients with patellar instability. The objective assessment of trochlear dysplasia with axial imaging MRI is reliable. The objective measurements of TDI, LTI, and MCTO are more reproducible than the more subjective Dejour classification. The TDI, LTI, and MCTO all significantly differentiated patients with patellar instability.

Does operative fixation affect outcomes of displaced medial epicondyle fractures?

PURPOSE: Long-term functional results remain equivocal between operative fixation and closed management of displaced humeral medial epicondyle fractures. The purpose of this study was to determine whether a functional difference exists between treatment types. METHODS: One hundred and forty patients with a displaced medial epicondyle fracture between 2007 and 2014 met the inclusion criteria. Of this large cohort, only 12 patients agreed to return to clinic at a mean follow-up of 3 years for prospective evaluation. Data collection included radiographs, physical examination, validated outcome tools, and grip strength testing with a Jamar dynamometer. RESULTS: Both groups were comparable with regard to age, dominant side injured, length of follow-up, preinjury sports involvement, and initial displacement (10 mm operative vs. 9 mm nonoperative); however, half of the surgical group presented with an associated unreduced elbow dislocation versus 0 % in the nonoperative group. Both treatment methods resulted in high patient satisfaction and elbow function scores. There were four osseous nonunions (67 %) and one malunion (17 %) in the nonoperative group versus none in the operative group (p = 0.015). Patients treated nonoperatively had a nonsignificant decrease in grip strength (9 ± 6 lbs) as compared to operative patients (6 ± 5 lbs, medium effect size eta = 0.25, p = 0.25). CONCLUSIONS: In this small cohort, operative management of displaced medial epicondyle fractures resulted in a higher rate of fracture union and return to sports. Other objective and subjective measures were similar between the two treatment groups.

Combined Tibial Tubercle Avulsion Fracture and Patellar Avulsion Fracture: An Unusual Variant in an Adolescent Patient.

Traumatic extensor dysfunction of the knee in children is a rare injury, with the majority resulting from tibial tubercle avulsion fracture or patellar sleeve fracture. We report a rare case of combined patellar avulsion fracture and tibial tubercle fracture. With open anatomic reduction, both injuries were successfully treated. While many variations of tibial tubercle fracture have been reported, the authors believe this to be the first report in the English-language literature of this particular combined injury to the knee extensor mechanism in an adolescent. Advanced imaging with computed tomography provided vital information to aid with operative planning, especially since the majority of the unossified tubercle was not seen on plain radiographs, and all fracture fragments were originally believed to be from the tibial tubercle. Computed tomography distinguished the patellar fracture from the tibial tubercle fragments, verifying preoperatively the complexity of the injury.

Posterior interosseous and ulnar nerve motor palsies after a minimally displaced radial neck fracture.

Peripheral nerve injury is a serious potential complication following an upper extremity fracture. A rare case of acute posterior interosseous nerve and ulnar nerve palsy following a minimally displaced radial neck fracture is reported. With nonsurgical management, both nerves demonstrated excellent functional recovery. Although rare, nerve palsies can occur during a variety of upper extremity clinical situations, including minimally displaced fractures, and the importance of a detailed neurologic examination cannot be overstated.