Clinical Outcomes of Ulnar Collateral Ligament Surgery in Nonthrowing Athletes.

BACKGROUND: Ulnar collateral ligament (UCL) surgery continues to demonstrate excellent clinical outcomes and a high return-to-play (RTP) rate with a low complication rate. Recent studies have demonstrated similar clinical outcomes for baseball players who have undergone either UCL reconstruction or UCL repair. In comparison, few studies have assessed the clinical outcomes of UCL surgery for nonthrowing athletes. PURPOSE/HYPOTHESIS: The primary objective of this study is to provide clinical outcomes of UCL surgery performed in nonthrowing athletes at a single institution with a minimum 2-year follow-up. Our hypothesis was that these patients would have similar clinical outcomes, complication rates, and RTP rates when compared with throwing athletes. LEVEL OF EVIDENCE: Case series; Level of evidence, 4. METHODS: From our longitudinal elbow registry, 40 nonthrowing athletes were identified who underwent UCL surgery (repair or reconstruction) between 2011 and 2019. Participant characteristics were recorded: age, sex, laterality, arm dominance, sport, level of competition, and type of surgery (UCL repair or reconstruction). Outcomes included RTP rate and average time, American Shoulder and Elbow Surgeons (ASES) scores, and complications. RESULTS: From the 40 patients eligible for inclusion in this study with a minimum 2-year follow-up, 37 (93%) were successfully contacted: 16 male (43%) and 21 female (57%). Mean ± standard deviation age at the time of surgery was 18.0 ± 3.7 years. From the 37 technical procedures, 28 (76%) were UCL repairs and 9 (24%) were UCL reconstructions. For these patients, 15 (41%) had partial tears, 20 (54%) had complete tears, 1 (3%) had a medial epicondyle avulsion, and 1 (3%) had an unspecified pathology. Sports included football (n = 11), gymnastics (11), cheerleading (7), wrestling (4), volleyball (2), basketball (1), and acrobatics (1). Quarterbacks were excluded from the football patients, as quarterbacks are throwing athletes. Level of competition included high school (n = 26), college (8), professional (2), and youth sports (1). The RTP rate was 93% (26/28) at a mean 7.4 months for UCL repair and 100% (9/9) at a mean 10.0 months for UCL reconstruction. Mean ASES scores were 94.4 and 98.7 for UCL repair and reconstruction, respectively. Complications were low, with 2 patients in the UCL repair group requiring ulnar nerve transposition for ulnar nerve paresthesia. CONCLUSION: In nonthrowing athletes, patients undergoing UCL repair and UCL reconstruction show favorable outcomes at minimum 2-year follow-up. RTP and clinical outcomes are consistent with previous studies in baseball players as well as a parallel ongoing study conducted on non-baseball throwing athletes.

Pediatric Diaphyseal Femur Fractures: Submuscular Plating Compared With Intramedullary Nailing.

This study compared the radiographic and clinical outcomes of pediatric diaphyseal femur fractures treated by submuscular plating, flexible retrograde intramedullary nailing, or rigid antegrade intramedullary nailing with a trochanteric entry point in skeletally immature patients who were 8 years and older. A retrospective review was conducted of skeletally immature patients 8 years and older who were treated for femur fracture with submuscular plating, flexible intramedullary nailing, or rigid intramedullary nailing from 2001 to 2014 with a minimum 12-week follow-up. Treatment outcomes were compared for statistical significance, including time to union, malunion, nonunion, heterotopic ossification, avascular necrosis, time to full weight bearing, limb length discrepancy, residual limp, painful hardware, and infection. The study identified 198 femur fractures in 196 patients (mean age, 11.9 years). Each femur fracture was treated with submuscular plating (35), flexible intramedullary nailing (61), or rigid intramedullary nailing (102). Mean follow-up across the cohort was 48 weeks, ranging from 12 to 225 weeks. Flexible nailing was associated with an increased incidence of malunion (P<.0001) and hardware irritation (P=.0204) and longer time to full weight bearing (P=.0018). Rigid nailing was associated with an increased incidence of limp at 12-week followup (P=.0412). Additionally, 23.5% of patients who were treated with rigid nailing had heterotopic ossification. Of all surgical methods, submuscular plating allowed for the most rapid return to full weight bearing (mean, 7 weeks) and offered the fastest healing rate (mean, 6 weeks). Submuscular plating resulted in faster times to union and full weight bearing, with minimal complication rates. Rigid intramedullary nailing with trochanteric entry resulted in a lower incidence of malunion and hardware-related complications; however, these patients had an increased incidence of heterotopic ossification and residual limp postoperatively. Flexible retrograde intramedullary nailing resulted in the highest rates of malunion and hardware irritation and the longest time to full weight bearing. [Orthopedics. 2016; 39(6):353-358.].

Serendipitous Offline Learning in a Neuromorphic Robot.

We demonstrate a hybrid neuromorphic learning paradigm that learns complex sensorimotor mappings based on a small set of hard-coded reflex behaviors. A mobile robot is first controlled by a basic set of reflexive hand-designed behaviors. All sensor data is provided via a spike-based silicon retina camera (eDVS), and all control is implemented via spiking neurons simulated on neuromorphic hardware (SpiNNaker). Given this control system, the robot is capable of simple obstacle avoidance and random exploration. To train the robot to perform more complex tasks, we observe the robot and find instances where the robot accidentally performs the desired action. Data recorded from the robot during these times is then used to update the neural control system, increasing the likelihood of the robot performing that task in the future, given a similar sensor state. As an example application of this general-purpose method of training, we demonstrate the robot learning to respond to novel sensory stimuli (a mirror) by turning right if it is present at an intersection, and otherwise turning left. In general, this system can learn arbitrary relations between sensory input and motor behavior.

Standardization of patellofemoral morphology in the pediatric knee.

BACKGROUND: Our understanding of osseous morphology and pathology of the patellofemoral joint continues to improve with the use of magnetic resonance imaging (MRI), but a paucity of data currently exists in the pediatric population. OBJECTIVE: We aim to formulate a reproducible means of quantitative assessment of patellofemoral morphology in children using MRI and to describe morphological changes based on sex and age. MATERIALS AND METHODS: We identified 414 children presenting between 2002 and 2014 who obtained a knee MRI to evaluate for knee pain or clinically suspected knee pathology. After application of inclusion criteria, 144 "normal" MRIs in 131 children (71 boys, 60 girls) were included in the analysis. The following MRI measurements were recorded: lateral trochlear inclination, trochlear facet asymmetry, trochlear depth, tibial tuberosity-trochlear groove distance, sulcus angle and patellar height ratio. To assess intraobserver reliability, measurements in 30 randomly selected children were repeated. Differences between patient age and sex were assessed using independent t-tests and adjusted regression analysis. RESULTS: All recorded measurements had strong to very strong inter- and intraobserver reliability: lateral trochlear inclination (0.91/0.82), trochlear facet asymmetry (0.81/0.83), trochlear depth (0.83/0.90), tibial tuberosity-trochlear groove distance (0.97/0.87), sulcus angle (0.84/0.78) and patellar height ratio (0.96/0.83). When age and sex were mutually adjusted, statistically significant differences between males and females were observed in trochlear depth (P = 0.0084) and patellar height ratio (P = 0.0035). However, statistically significant age differences were found on all measurements except for lateral trochlear inclination. As expected, mean measurement values approached adult norms throughout skeletal maturation suggestive of age-dependent patellofemoral maturation. CONCLUSION: Our data verify the development of patellofemoral morphology with advancing age. We found that six of the most commonly used patellofemoral measurements in adults can be accurately reproduced regardless of age.

Incidence of Hip Dysplasia Associated With Bladder Exstrophy.

BACKGROUND: Exstrophy of the bladder is a rare congenital defect seen in 2.15 children out of every 100,000 live births, with the most severe variant, cloacal exstrophy (CE), only occurring in 1 in 200,000. Developmental dysplasia of the hip (DDH) describes a spectrum of disease ranging from mild hip instability to frank dislocation. Underlying malformations, such as myelomeningocele and arthrogryposis, are often associated with the most severe variant of hip dysplasia, teratologic hip dislocation. The varying degrees of severity in DDH have been encountered in classic bladder exstrophy (CBE) patients, but the exact incidence is unknown. We sought to determine the incidence of DDH in CBE and CE patients. METHODS: We performed a retrospective review of all children with CBE or CE presenting to a single pediatric center between 1994 and 2014. Each chart was reviewed for correct diagnosis of CBE or CE, patient age and demographics, associated medical conditions, pertinent surgeries performed, and the age at operation. Patient imaging was reviewed to determine whether bilateral hip imaging was available. RESULTS: In a 20-year retrospective review, we identified 66 patients who were diagnosed with either CBE or CE and had available hip imaging (38 males and 28 females). Of these, 11 patients were found to have radiographic evidence of DDH, for an incidence of 16.7% (11/66). Five of these patients had CE, whereas 6 presented with CBE. The first radiographic evidence of DDH was noted at a mean age of 5.75 years (range, birth to 22 y). CONCLUSIONS: We advocate the use of routine hip screening ultrasound in all infants born with either CBE or CE. Early identification of DDH in these patients may allow additional treatment options to coincide with frequently used osteotomy and orthopaedic interventions. LEVEL OF EVIDENCE: Level III-retrospective study.

Traumatic, Posterior Pediatric Hip Dislocations With Associated Posterior Labrum Osteochondral Avulsion: Recognizing the Acetabular "Fleck" Sign.

BACKGROUND: Traumatic dislocation of the hip is uncommon in the pediatric population. Concentric reduction is usually achieved by closed means. Open reduction may be needed if there is femoral head fracture, incarcerated fragment, or incomplete reduction due to soft tissue entrapment. We present a series of 10 patients who sustained a posterior hip dislocation or subluxation with associated osteochondral avulsion of the posterior labrum. During surgery they were noted to have a labral injury pattern not previously recognized. Such treatment was dictated by postreduction advanced imaging, which revealed a consistent acetabular "fleck" sign indicative of this labral injury, which has not been previously described in literature. METHODS: We performed a retrospective case review of patients with traumatic posterior hip dislocation/subluxation, treated operatively for a suspected associated labral tear and fractures. RESULTS: Ten patients (2 girls and 8 boys) were identified. Average age was 12.7 years. Eight patients had postreduction computed tomography scans, which revealed a posterior acetabular wall "fleck" sign, suggestive of osteochondral injury. The small bony fragment was consistently displaced at least 2 to 3 mm in all patients with majority of the posterior wall remaining intact. Closed reduction was felt to be congruent in 7 of the 10 patients. All patients were treated operatively for exploration and stabilization of the suspected posterior labrum pathology and associated injuries using a surgical hip dislocation. A consistent pattern of labral pathology was seen in all patients, with disruption of the posterior labrum from the superior 12 o'clock attachment to detachment at the inferior 6 o'clock location. Reattachment of the osteochondral labral avulsion was performed with suture anchors along the posterior rim, and the associated femoral head fractures were also addressed with internal fixation. Two patients had inadequate follow-up and were excluded, the average follow-up for the remaining 8 patients was 9.8 months (range, 6 to 26 mo). There were no findings of avascular necrosis in any of the 8 patients. CONCLUSIONS: Posterior hip dislocation in children may produce an acetabular "fleck" sign on advanced imaging, which in a stable, concentrically reduced hip has been treated without surgery in the past. Acetabular fleck sign may represent a near-complete avulsion of the posterior labrum as seen in our series. We recommend a high suspicion for this type of labral pathology and surgical repair when acetabular "fleck" sign is identified with hip subluxation or dislocation. Traumatic, posterior hip dislocations in young patients may be associated with significant labral pathology. Acetabular "fleck" sign on advanced imaging may predict such pathology. LEVEL OF EVIDENCE: IV, retrospective study.

Radiographic Assessment of Anatomic Risk Factors Associated with Acute, Lateral Patellar Dislocation in the Immature Knee.

Acute patellar dislocation remains a common injury in both adult and pediatric patients. Non-operative management has been advocated for patients without a history of recurrent instability. Although pathologic thresholds for consideration of operative management have previously been reported in adults, it is largely unknown in children. A retrospective review of all skeletally immature patients diagnosed with acute lateral patellar dislocation who had MRI imaging were included for analysis. An age-based control group was also identified. Six radiographic measurements were compared: lateral trochlear inclination (LTI), trochlear facet asymmetry (TFA), trochlear depth (TD), tibial tuberosity⁻trochlear groove (TT⁻TG), sulcus angle (SA) and patellar height ratio. A total of 178 patients were included for analysis (study: n = 108, control: n = 70). The mean age of patients in the study and control groups was 13.7 and 12.1 years respectively (p ≤ 0.001). Study group patients had significant differences in all radiographic measurements including a decreased LTI (p < 0.001), increased TFA (p < 0.001) and SA (p < 0.001). The mean trochlear depth was 3.4 mm and 5.6 mm for patients in the study and control groups respectively (p < 0.001). Study group patients had an increased patellar height ratio (p < 0.001) and TT⁻TG distance (p < 0.001). Morphologic abnormalities may predispose skeletally immature patients to an increased risk of acute lateral patellar instability.