Subperiosteal delivery of transforming growth factor beta 1 and human growth hormone from mineralized PCL films.

The ability to locally deliver bioactive molecules to distinct regions of the skeleton may provide a novel means by which to improve fracture healing, treat neoplasms or infections, or modulate growth. In this study, we constructed single-sided mineral-coated poly-ε-caprolactone membranes capable of binding and releasing transforming growth factor beta 1 (TGF-ß1) and human growth hormone (hGH). After demonstrating biological activity in vitro and characterization of their release, these thin bioabsorbable membranes were surgically implanted using an immature rabbit model. Membranes were circumferentially wrapped under the periosteum, thus placed in direct contact with the proximal metaphysis to assess its bioactivity in vivo. The direct effects on the metaphyseal bone, bone marrow, and overlying periosteum were assessed using radiography and histology. Effects of membrane placement at the tibial growth plate were assessed via physeal heights, tibial growth rates (pulsed fluorochrome labeling), and tibial lengths. Subperiosteal placement of the mineralized membranes induced greater local chondrogenesis in the plain mineral and TGF-ß1 samples than the hGH. More exuberant and circumferential ossification was seen in the TGF-ß1 treated tibiae. The TGF-ß1 membranes also induced hypocellularity of the bone marrow with characteristics of gelatinous degeneration not seen in the other groups. While the proximal tibial growth plates were taller in the hGH treated than TGF-ß1, no differences in growth rates or overall tibial lengths were found. In conclusion, these data demonstrate the feasibility of using bioabsorbable mineral coated membranes to deliver biologically active compounds subperiosteally in a sustained fashion to affect cells at the insertion site, bone marrow, and even growth plate.

Hip Pain in Nonambulatory Children with Type-I or II Spinal Muscular Atrophy.

The purpose of the present study was to define the prevalence of hip pain in nonambulatory children with spinal muscular atrophy (SMA) (type I or II) treated with aggressive medical management, prior to widespread use of disease-modifying therapies (DMTs). Methods: A retrospective chart review (1993 to 2017) was performed on children diagnosed with SMA to identify subjective reports of hip pain and associated interventions, while radiographs were evaluated to assess hip instability and spinal deformity. Results: Seventy-two patients (33 with type I and 39 with type II) met the inclusion criteria. Hip pain was more frequent in type-II SMA (49% versus 12%; p = 0.001). Seventeen percent of the patients with 2 copies of the SMN2 (survival motor neuron 2) gene, 53% of patients with 3 copies, and 1 of the 2 patients with 4 copies reported hip pain. Nearly all patients had abnormal findings on hip radiographs made at the onset of pain or at the latest follow-up; however, no patient with type-I and 18% of those with type-II SMA had pain that was severe enough to undergo invasive intervention (p = 0.01). The intervention reduced the pain in most of those patients but completely eliminated it in only 1 patient. No significant differences were found with respect to the mean age at the onset of scoliosis, the mean age at the time of scoliosis surgery, or whether insertion of growing rods or posterior spine fusion was performed between those with and without hip pain requiring invasive treatment. Conclusions: This study is, to our knowledge, the largest investigation to date to assess hip pain among nonambulatory children with type-I or type-II SMA and suggests that symptoms rather than radiographs be utilized to direct care. These data will be crucial in assessing any effects that the new DMTs have on the natural history of hip pathology and pain in nonambulatory patients with SMA. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Novel Cast-saw Alarm System Reduces Blade-to-Skin Contact in a Pediatric Upper Extremity Model.

PURPOSE: To determine the effectiveness of a novel cast-saw alarm system in minimizing the number and duration of cast-saw blade-to-skin contacts. METHODS: Twenty orthopaedic residents removed a pair of long-arm casts applied to instrumented pediatric upper extremity models. The model and cast-saw were instrumented to detect blade to "skin" contact at a rate of 600 Hz. Each resident performed cast removal with and without the use of a cast-saw alarm, the order of which was randomized. Eleven additional "new" cast-saw users then removed pairs of casts, without and then with the cast alarm, to evaluate what effect the alarm would have on preventing blade-to-skin contact in users with no previous cast-saw experience. The number and duration of cast-saw touches were then evaluated. Statistical significance was determined paired 1-sided students t tests (number of touches). RESULTS: For the residents (n=20), the total number of blade-to-skin contacts was 233. One hundred eighty-one blade-to-skin contacts without the alarm and 52 with the alarm (71% reduction) (t(19)=-3.42, P=0.001), averaging 6.45 more blade-to-skin contacts per cast without the alarm. The median blade-to-skin contact duration was 0.166 seconds without the alarm and 0.087 seconds with the alarm. This was a 48% reduction in contact time (P=0.073). For the inexperienced users (n=11), the total number of blade-to-skin contacts was 356, 324 blade-to-skin contacts without the alarm and 32 with the alarm (90% reduction) (t(10)=-2.78, P=0.009), averaging 26.5 more blade-to-skin contacts without the alarm. The median blade-to-skin contact duration for the novice was 0.313 seconds without the alarm and 0.1 seconds with the alarm (68% reduction). Contact time was reduced in both groups but failed to reach statistical significance. However, alarm use significantly reduced the number of touches of >0.5 seconds duration (62 vs. 3) in the novice group, P=0.0176. Blade-to-skin contact of >0.5 seconds were felt to represent touches that were more likely to result in thermal injury to a living patient. CONCLUSION: Blade-to-skin contact can be reduced with the use of a cast-saw alarm. These effects appear most amplified in users with little prior cast-saw experience. LEVEL OF EVIDENCE: Not applicable.

Histological and radiographic evaluation of three common tendon transfer techniques in an un-ossified bone porcine model: implications for early anterior tibialis tendon transfers in children with clubfeet.

PURPOSE: To compare the histological healing and radiographic effects of tendons transferred to ossified or unossified bone using different tendon fixation techniques. METHODS: Nine new-born piglets underwent bilateral tendon transfers to either the ossified boney calcaneal body or unossified apophysis. The tendons were fixed using metallic suture anchors, sutures alone or a bone tunnel. At six weeks of age, calcanei were harvested, radiologically imaged and then prepared for histology. A semi-quantitative aggregated scoring system with values ranging from 0 (poor) to 15 (excellent), was used to grade healing at the surgical enthesis and the apophyseal ossification was graded by five independent reviewers in triplicate using a modified (1 to 4) validated scoring system. RESULTS: Histologically, the cartilaginous transfers utilizing the tunnel and suture techniques also demonstrated the best average aggregated scores of entheses healing rivalling that measured in transfers using the classic bone tunnel technique (clinical benchmark), whereas suture anchor fixation demonstrated the worst healing in both the ossified and unossified samples. All three transfer techniques caused at least minor alterations in apophyseal ossification, with the most significant changes observed in the metallic suture anchor cohort. The tunnel and suture techniques demonstrated similar and more mild abnormalities in ossification. CONCLUSION: Tendon transfers to unossified bone heal histologically as well as transfers classically performed through tunnels in bone. Suture fixation or tunnel techniques appear radiographically and histologically superior to suture anchors in our newborn porcine model.

A Prospective, Median 15-Year Comparison of Ponseti Casting and Surgical Treatment of Clubfoot.

BACKGROUND: In 2010, 2 authors of this current study reported the results of Ponseti treatment compared with primary posteromedial release (PMR) for congenital talipes equinovarus in a cohort of 51 prospective patients. This current study shows outcomes recorded at a median of 15 years after the original treatment. METHODS: Patient health records were available for all 51 patients at a median of 15 years (range, 13 to 17 years) following treatment of congenital talipes equinovarus with either the Ponseti method (25 patients [38 feet]) or PMR (26 patients [42 feet]). Thirty-eight of 51 patients could be contacted, and 33 patients (65%) participated in the clinical review, comprising patient-reported outcomes, clinical examination, 3-dimensional gait analysis, and plantar pressures. RESULTS: Sixteen (42%) of 38 Ponseti-treated feet and 20 (48%) of 42 PMR-treated feet had undergone a further surgical procedure. The PMR-treated feet were more likely to undergo osteotomies and intra-articular surgical procedures (15 feet) than the Ponseti-treated feet (5 feet) (p < 0.05). Of the 33 patients reviewed with multimodal assessment, the Ponseti group, compared with the PMR group, demonstrated better Dimeglio scores (5.8 compared with 7.0 points; p < 0.05), Disease Specific Instrument (80.7 compared with 65.6 points; p < 0.05), Functional Disability Inventory (1.1 compared with 5.1; p < 0.05), and American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle Outcomes Questionnaire scores (52.2 compared with 46.6 points; p < 0.05), as well as improved total sagittal ankle range of motion in gait and ankle plantar flexion range at toe-off. The PMR group with clinical hindfoot varus displayed higher pressures in the lateral midfoot and the forefoot. CONCLUSIONS: Although the numbers of repeat surgical interventions following Ponseti treatment and primary PMR were similar, the PMR-treated feet had greater numbers of osteotomies and intra-articular surgical procedures. Functional outcomes were improved at a median of 15 years for feet treated with the Ponseti method compared with feet treated with PMR, with advantages seen in the Ponseti group over several domains. This study provides the most comprehensive evaluation of outcomes close to skeletal maturity in prospective cohorts, reinforcing the Ponseti method as the initial treatment of choice for idiopathic clubfeet. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Quality of Life Outcomes According to Differential Nusinersen Exposure in Pediatric Spinal Muscular Atrophy.

The purpose of this study was to explore early changes in patient and family caregiver report of quality of life and family impact during the transitional period of nusinersen use. Communication; family relationships; physical, emotional, social, and cognitive functioning; and daily activities were measured using Pediatric Quality of Life modules (Family Impact Modules and both Patient and Proxy Neuromuscular-Specific Reports) pre- and post-nusinersen exposure. A total of 35 patients with SMA (15 Type 1, 14 Type 2, and 6 Type 3) were grouped according to nusinersen exposure. When analyzed as a whole cross-sectional clinical population, no significant differences were found between the initial and final surveys. Nusinersen therapy was associated with improved communication and emotional functioning in subsets of the population, particularly for patients on maintenance therapy for longer duration. Several unexpected potentially negative findings including increases in family resources and trends towards increases in worry warrant further consideration. Further research is warranted to explore the impact of novel pharmaceuticals on quality of life for children with SMA longitudinally to optimize clinical and psychosocial outcomes.

Sagittal Plane Deformities in Children with SMA2 following Posterior Spinal Instrumentation.

This is a retrospective radiographic review to assess post-operative sagittal plane deformities in patients with Spinal Muscular Atrophy type 2 that had been treated with posterior spinal instrumentation. Thirty-two patients with a history of either spinal fusion (N = 20) or growing rods (N = 12) were identified with an average of 7.6 (2.1-16.6) years post-operative follow-up. Forty percent (13/32) of the patients were identified as having obvious "tucked chin" (N = 4), "tipped trunk" (N = 9), or both (N = 3). Sacral incidence was the only parameter that was statistically significant change between pre-operative or immediate post-operative measurements (66.9° vs. 55.2° p = 0.03). However, at final follow-up, the post-operative thoracic kyphosis had decreased over time in those that developed a subsequent sagittal deformity (24.2°) whereas it increased in those that did not (44.7°, p = 0.008). This decrease in thoracic kyphosis throughout the instrumented levels, resulted in a greater lordotic imbalance (30.4° vs. 5.6°, p = 0.001) throughout the instrumented levels in the group that developed the subsequent cervical or pelvic sagittal deformities. In conclusion, sagittal plane deformities commonly develop outside the instrumented levels in children with SMA type 2 following posterior spinal instrumentation and may be the result of lordotic imbalance that occurs through continued anterior growth following posterior instrumentation.

Keeping casts dry: A comparison of commercially available cast protectors using a mechanized short arm cast model.

BACKGROUND: Upper extremity fractures requiring cast immobilization are exceedingly common, especially in the pediatric population. Studies have shown improved outcomes when patients can participate in water-based activities while casted. However, waterproof cast material is not feasible in all clinical settings and wet cast complications remain a source of morbidity and expense. External cast protectors play an important role in preventing wet casts, but the efficacy of various commercially available brands during relevant water-based activity remains unknown. PURPOSES: To determine if there are differences in the rate and extent of moisture exposure for four commercially available cast protectors using a mechanized cast arm model and human volunteers. METHODS: A mechanized arm model was developed with four implanted humidity sensors. Cast protectors were applied over the arm, the model was submerged in water, and moved back and forth, simulating cast-wearers' motion. Data regarding humidity was recorded for successive 10-minute trials. Trials were analyzed using a mixed effects linear model to determine change in humidity over time. The top and bottom performing cast protectors were then applied to four adult volunteers prior to thirty minutes of swimming. Questionnaires regarding comfort and a qualitative assessment of cast wetness using a chemical color indicator were completed. RESULTS: 372 instances of sensor data from 96 10-minute trials was collected. The CVS, SealTight and Walgreens brands showed significant increases in humidity beginning at 10, 20 and 20 minutes, respectively. DryPro showed no significant increase in moisture level up to 50 minutes. In successive trials up to 120 minutes, DryPro showed only a 2% increase in moisture. In human subjects testing, 3/4 casts underneath CVS protectors had some degree of wetness-related color change that would require cast change as compared to 0/4 casts underneath DryPro protectors. CONCLUSIONS: Significant differences exist between commercially available cast protectors. Vacuum-sealed protectors performed best in both mechanical and human subject portions of this study and allowed minimal change in humidity for extended periods of sequential water immersion. Their cost is notably less than management of a wet cast. Lower-performing products may expose cast-wearers to an increased risk of wet cast complications.

Exosome-educated macrophages and exosomes differentially improve ligament healing.

Recently, our group used exosomes from mesenchymal stromal/stem cells (MSCs) to simulate an M2 macrophage phenotype, that is, exosome-educated macrophages (EEMs). These EEMs, when delivered in vivo, accelerated healing in a mouse Achilles tendon injury model. For the current study, we first tested the ability of EEMs to reproduce the beneficial healing effects in a different rodent model, that is, a rat medial collateral ligament (MCL) injury model. We hypothesized that treatment with EEMs would reduce inflammation and accelerate ligament healing, similar to our previous tendon results. Second, because of the translational advantages of a cell-free therapy, exosomes alone were also examined to promote MCL healing. We hypothesized that MSC-derived exosomes could also alter ligament healing to reduce scar formation. Similar to our previous Achilles tendon results, EEMs improved mechanical properties in the healing ligament and reduced inflammation, as indicated via a decreased endogenous M1/M2 macrophage ratio. We also showed that exosomes improved ligament remodeling as indicated by changes in collagen production and organization, and reduced scar formation but without improved mechanical behavior in healing tissue. Overall, our findings suggest EEMs and MSC-derived exosomes improve healing but via different mechanisms. EEMs and exosomes each have attractive characteristics as therapeutics. EEMs as a cell therapy are terminally differentiated and will not proliferate or differentiate. Alternatively, exosome therapy can be used as a cell free, shelf-stable therapeutic to deliver biologically active components. Results herein further support using EEMs and/or exosomes to improve ligament healing by modulating inflammation and promoting more advantageous tissue remodeling.

Cervical Kyphosis in Spinal Muscular Atrophy: A Case Report.

CASE: A 12-year-old boy with spinal muscular atrophy (SMA) Type II presented 5 years after undergoing spinal growing rod placement with cervical kyphosis at C2-3. He underwent anterior cervical discectomy and fusion but 6 years later developed significant kyphosis at the adjacent C3-4 level. CONCLUSION: We describe a rare adjacent segment kyphotic condition in a young man with SMA Type II. Clinicians should be cognizant of the risk of cervical kyphosis in adolescent patients with SMA.

Biomechanical Evaluation of a Minimally Invasive Fixation Method for Length Unstable Limb Injuries.

INFIX instrumentation has provided an alternative treatment option for anteriorly unstable pelvic injuries. In this study, we explore the biomechanical feasibility of using an INFIX construct in an unstable longbone model and present a unique clinical case of its use. The external fixation, locked plate and spinal implant constructs (n = 5 each) were applied to lengthunstable fracture models and tested under various loads. Analysis of variance and pairwise Ttests were performed with levels of significance adjusted by Bonferroni correction to account for multiple comparisons. The biomechanical stiffness of the INFIX was found to be intermediate between the other two constructs in axial loading and torsion and was equivalent to one of the other constructs in sagittal and lateral bending. It was never the most compliant construct in any testing mode. This study and case report demonstrate the biomechanical feasibility of using INFIX to treat limb injuries. (Journal of Surgical Orthopaedic Advances 29(1):1825, 2020).

Is prophylactic formal fusion with implant revision necessary in non-ambulatory children with spinal muscular atrophy and growing rods who are no longer lengthened?

STUDY DESIGN: Single center, retrospective chart review. OBJECTIVES: To determine if routine posterior spinal fusion (PSF) is unnecessary in non-ambulatory growing rod graduates with SMA. Most non-ambulatory children with SMA develop early-onset scoliosis (EOS). Posterior growing rods (GR) have been shown safe and effective in managing spinal deformities in these children. The best management of these children, once graduated from their GR, is currently unknown. In this study, we report the clinical results of managing these children without routine definitive fusion following a course of GR treatment. METHODS: A single-center, retrospective chart and radiographic review was performed on children with SMA treated with posterior distraction GR, with a two-year minimum follow-up since final lengthening. Electronic medical records and radiographs were reviewed for demographic variables, Cobb measurements, implant revisions, occult radiographic implant failure, symptomatic failure, and/or conversion to PSF. RESULT: 12 patients (2 type 1, 9 type 2, 1 type 1/2) met inclusion criteria. Mean age at growing rod insertion was 6.2 years of age (range 4.1-8.2) and age at final lengthening 10.3 years of age (range 9.3-11.9). The mean time between last lengthening and latest clinical or radiographic review was 5.5 (range 2.1-9.0) years. Average mean pre, post, final Cobb angles were 71°, 27° (p < 0.001), 25°. Following final lengthening, only one patient required hardware revision and conversion to definitive fusion in attempts to alleviate chronic hip pain, which was unsuccessful. One additional patient was found to have an occult rod failure that has not required treatment. CONCLUSION: While limited by sample size, this single-center cohort of non-ambulatory SMA patients with EOS treated with similar constructs suggests that routine, definitive fusion in SMA GR graduates may be unnecessary. LEVEL OF EVIDENCE: Level IV.

A Prospective, Crossover Survey Study of Child- and Proxy-Reported Quality of Life According to Spinal Muscular Atrophy Type and Medical Interventions.

BACKGROUND: Spinal muscular atrophy is an autosomal-recessive, progressive neuromuscular disease associated with extensive morbidity. Children with spinal muscular atrophy have potentially increased life spans due to improved nutrition, respiratory support, and novel pharmaceuticals. OBJECTIVES: To report on the quality of life and family experience for children with spinal muscular atrophy with attentiveness to patient- and proxy-concordance and to stratify quality of life reports by spinal muscular atrophy type and medical interventions. METHODS: A prospective, crossover survey study inclusive of 58 children (26 spinal muscular atrophy type I, 23 type II, 9 type III) and their family caregivers at a free-standing Midwestern children's hospital. Twenty-eight families completed the 25-item PedsQL 3.0 Neuromuscular Module. Forty-four participants completed the 36-item PedsQL Family Impact Module and 47 completed the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) questionnaire. RESULTS: The PedsQL Family Impact Module demonstrated significant differences between spinal muscular atrophy types I and II in functioning domains including physical, emotional, social, and family relations (P < .03). Child self-report and proxy report surveys demonstrated significant differences between spinal muscular atrophy types in the communication domains (P < .003). Children self-reported their quality of life higher than proxy report of child quality of life. Gastrostomy tube (P = .001) and ventilation support (P = .029) impacted proxy-reported quality of life perspectives, whereas nusinersen use did not. Spinal surgery was associated with improved parental quality of life and family impact (P < .03). CONCLUSIONS: The measurement and monitoring of quality of life for children with spinal muscular atrophy and their families represents an implementable priority for care teams.

Does an intrathecal baclofen pump impact scoliosis progression and complicate posterior spine fusion in patients with cerebral palsy?

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: In patients with cerebral palsy (CP), we determine the impact of intrathecal baclofen pumps (ITBPs) on scoliosis curve progression before posterior spine fusion (PSF) and its effects on surgical outcome. BACKGROUND: Children with CP can have rapid scoliosis progression, and high rates of surgical complications can be encountered. It is unknown whether the presence of pre-existing ITBP results in more difficult surgery and higher complication rates in similarly affected children. METHODS: This is a single-center retrospective study of CP patients undergoing PSF over a 15-year period. Demographics, comorbidities, curve magnitudes, and surgical methods were compared between patients with ITBP and those without. Postoperative complications, length of intensive care unit/hospital stay, drain use and output volume, and need for further surgery were also compared. Curve progression analysis after ITBP placement was performed on a subgroup of patients with high-quality consistent radiographs. RESULTS: Nineteen patients with ITBP and 49 patients without ITBP met inclusion criteria. Age, comorbidities, number of levels fused, and fixation techniques during PSF were not significantly different between cohorts. ITBP patients were more likely to have PSF with osteotomy (p = 0.022). Increased intraoperative neurosurgical consultations were found for patients with ITBP (42.1% vs. 4.0%; p < 0.001). Median surgical time was 1.2 h greater in patients with ITBP (6.7 vs. 5.5 h, p = 0.039). There was no difference in hospital course and complications in patients with ITBP and those without ITBP. Thirty-one patients without ITB were compared with 15 ITBP patients for curve progression before PSF, demonstrating a mean rate of scoliosis progression of 9.6° ± 6.7°/year and 14.8° ± 9.1°/year (p = 0.0346), respectively. CONCLUSION: The presence of an ITBP appears to be associated with the increase in scoliosis progression; and these patients will likely have a more challenging spine fusion. Fortunately, the final outcome is not affected by ITBP. LEVEL OF EVIDENCE: Level III.

Peri-operative management of children with spinal muscular atrophy.

BACKGROUND AND AIMS: Current multi-disciplinary management of children with spinal muscular atrophy (SMA) often requires the surgical management of spinal deformities. We present the outcomes of our peri-operative experience around the time of their spinal surgery and share our neuromuscular perioperative protocol. METHODS: A single-centre retrospective chart review was performed to evaluate all children with SMA types I and II that underwent thoracolumbar spinal deformity correction (posterior spinal fusion or growing rod insertion) from 1990 to 2015. Electronic medical records were reviewed to assess pre-operative, intraoperative, and postoperative variables. T-tests, Wilcoxon Rank Sum, Fisher's Exact tests were performed as appropriate. RESULTS: Twelve SMA I and twenty-two SMA II patients were included. Type I patients tended to be smaller and had a higher percentage (36.4% vs 4.5%) of American Society of Anesthesiologists (ASA) class 4 patients. Preoperative total parenteral nutrition (TPN) was utilised in 75.0% of type I and 18.2% type II patients. A difficult intubation was experienced in around 25% of the patients (20.0% SMA I, 27.3% SMA II). Approximately two hours of anaesthetic time was required in addition to the actual surgical time in both types. The intensive care unit (ICU) length of stay averaged 6 (4.0-7.5) days for type I and 3 (3-5) days for type II (p = 0.144). Average post-operative length of stay was (8 (7-9) vs. 7 (6-8)) P = 1.0. CONCLUSION: Children with type I and II SMA have similar hospital courses. The surgical and anaesthesia team should consider perioperative TPN and NIPPV (non-invasive positive-pressure ventilation), anticipate difficult intubations, longer than usual anaesthetic times, and potentially longer ICU stays in both SMA type I and II.

Cervical Spine Injury Following Thoracic Spinal Fusion for Adolescent Idiopathic Scoliosis.

Spinal fusion for adolescent idiopathic scoliosis (AIS) can have many potential complications, including spinal cord injury. Most often, spinal cord injury occurs in the region of surgery due to direct mechanical trauma. Vascular compromise in this area may also occur due to a high degree of correction or excessive distraction of the spine. In these cases, the impairment of spinal cord function is often detected intraoperatively with spinal cord monitoring and confirmed in the immediate postoperative period. Injury to the spinal cord above the level of instrumentation is rare. We review the clinical history and outcome of a female adolescent who underwent posterior spinal fusion (PSF) for AIS and developed a cervical spine injury 12 hours postoperatively. The patient is a 13-year old female who underwent PSF for AIS from T1 to L1 for progressive scoliosis measuring over 53 degrees in her right thoracic curve. During surgery, she had modest correction with minimal blood loss and with normal intraoperative motor evoked and somatosensory evoked potentials. The immediate postoperative examination was neurologically intact. Twelve hours later, she developed weakness and tingling in her right upper extremity. Magnetic resonance imaging (MRI) of the cervical spine demonstrated myelomalacia on the right side of the spinal cord at the C5-7 levels. Cervical spine injuries are rare following lower-level fusions, however, these injuries can occur and it is important to be vigilant in monitoring patients for these symptoms. The exact mechanism is unknown and may include a combination of postoperative hypotension with altered vascular anatomy from cord stretch and abnormal cervical positioning.

Open Vs. Closed Reduction in Type 2 Lateral Condyle Fractures.

Background: Lateral condyle fractures are associated with high morbidity due to their risk of nonunion and avascular necrosis (AVN). This study aims to assess the outcomes between closed reduction and the more traditional open techniques for operative fractures. Methods: All lateral condyle fractures that required operative fixation (pins or screws) over a ten-year period were included. We compared open versus closed reduction for OR time, infection rate, AVN, nonunion, premature physeal closure, ulnohumeral angle, and interepicondylar width (IEW). Results: 28 patients were identified in the closed reduction group while 41 were identified in the open reduction group. Average displacement at surgery for these two groups was significantly different at 3.95mm for the closed group and 9.47mm for the open group (p<0.0001). Operating room time was significantly greater for the open reduction group by an average of 45 minutes (p <0.0001). Additionally, the closed reduction group was significantly less likely to require postoperative admission compared to the open reduction group (p=0.0004). There were no significant differences between the two groups with regard to abnormal ulnohumeral angles, infection rates, avascular necrosis, nonunion, lateral spur formation, premature physeal closure, or reoperation rate. Conclusions: The significant differences in OR time and post-operative admission make closed reduction the preferred approach from a hospital system quality improvement standpoint.Level of Evidence: IV.

Extracellular Vesicle-Educated Macrophages Promote Early Achilles Tendon Healing.

Tendon healing follows a complex series of coordinated events, which ultimately produces a mechanically inferior tissue more scar-like than native tendon. More regenerative healing occurs when anti-inflammatory M2 macrophages play a more dominant role. Mesenchymal stromal/stem cells (MSCs) are able to polarize macrophages to an M2 immunophenotype via paracrine mechanisms. We previously reported that coculture of CD14+ macrophages (MQs) with MSCs resulted in a unique M2-like macrophage. More recently, we generated M2-like macrophages using only extracellular vesicles (EVs) isolated from MSCs creating "EV-educated macrophages" (also called exosome-educated macrophages [EEMs]), thereby foregoing direct use of MSCs. For the current study, we hypothesized that cell therapy with EEMs would improve in vivo tendon healing by modulating tissue inflammation and endogenous macrophage immunophenotypes. We evaluated effects of EEMs using a mouse Achilles tendon rupture model and compared results to normal tendon healing (without any biologic intervention), MSCs, MQs, or EVs. We found that exogenous administration of EEMs directly into the wound promoted a healing response that was significantly more functional and more regenerative. Injured tendons treated with exogenous EEMs exhibited (a) improved mechanical properties, (b) reduced inflammation, and (c) earlier angiogenesis. Treatment with MSC-derived EVs alone were less effective functionally but stimulated a biological response as evidenced by an increased number of endothelial cells and decreased M1/M2 ratio. Because of their regenerative and immunomodulatory effects, EEM treament could provide a novel strategy to promote wound healing in this and various other musculoskeletal injuries or pathologies where inflammation and inadequate healing is problematic. Stem Cells 2019;37:652-662.

Efficiency and Safety: The Best Time to Valve a Plaster Cast.

BACKGROUND: The act of applying, univalving, and spreading a plaster cast to accommodate swelling is commonly performed; however, cast saws can cause thermal and/or abrasive injury to the patient. This study aims to identify the optimal time to valve a plaster cast so as to reduce the risk of cast-saw injury and increase spreading efficiency. METHODS: Plaster casts were applied to life-sized pediatric models and were univalved at set-times of 5, 8, 12, or 25 minutes. Outcome measures included average and maximum force applied during univalving, blade-to-skin touches, cut time, force needed to spread, number of spread attempts, spread completeness, spread distance, saw blade temperature, and skin surface temperature. RESULTS: Casts allowed to set for ≥12 minutes had significantly fewer blade-to-skin touches compared with casts that set for <12 minutes (p < 0.001). For average and maximum saw blade force, no significant difference was observed between individual set-times. However, in a comparison of the shorter group (<12 minutes) and the longer group (≥12 minutes), the longer group had a higher average force (p = 0.009) but a lower maximum force (p = 0.036). The average temperature of the saw blade did not vary between groups. The maximum force needed to "pop," or spread, the cast was greater for the 5-minute and 8-minute set-times. Despite requiring more force to spread the cast, 0% of attempts at 5 minutes and 54% of attempts at 8 minutes were successful in completely spreading the cast, whereas 100% of attempts at 12 and 25 minutes were successful. The spread distance was greatest for the 12-minute set-time at 5.7 mm. CONCLUSIONS: Allowing casts to set for 12 minutes is associated with decreased blade-to-skin contact, less maximum force used with the saw blade, and a more effective spread. CLINICAL RELEVANCE: Adherence to the 12-minute interval could allow for fewer cast-saw injuries and more effective spreading.

Maternal Diets Deficient in Vitamin D Increase the Risk of Kyphosis in Offspring: A Novel Kyphotic Porcine Model.

BACKGROUND: The purpose of this study was to explore the role of perinatal vitamin-D intake on the development and characterization of hyperkyphosis in a porcine model. METHODS: The spines of 16 pigs were assessed at 9, 13, and 17 weeks of age with radiography and at 17 weeks with computed tomography (CT), magnetic resonance imaging (MRI), histology, and bone-density testing. An additional 169 pigs exposed to 1 of 3 maternal dietary vitamin-D levels from conception through the entire lactation period were fed 1 of 4 nursery diets supplying different levels of vitamin D, calcium, and phosphorus. When the animals were 13 weeks of age, upright lateral spinal radiography was performed with use of a custom porcine lift and sagittal Cobb angles were measured in triplicate to determine the degree of kyphosis in each pig. RESULTS: The experimental animals had significantly greater kyphotic sagittal Cobb angles at all time points when compared with the control animals. These hyperkyphotic deformities demonstrated no significant differences in Hounsfield units, contained a slightly lower ash content (46.7% ± 1.1% compared with 50.9% ± 1.6%; p < 0.001), and demonstrated more physeal irregularities. Linear mixed model analysis of the measured kyphosis demonstrated that maternal diet had a greater effect on sagittal Cobb angle than did nursery diet and that postnatal supplementation did not completely eliminate the risk of hyperkyphosis. CONCLUSIONS: Maternal diets deficient in vitamin D increased the development of hyperkyphosis in offspring in this model. CLINICAL RELEVANCE: This study demonstrates that decreased maternal dietary vitamin-D intake during pregnancy increases the risk of spinal deformity in offspring. In addition, these data show the feasibility of generating a large-animal spinal-deformity model through dietary manipulation alone.