Femorotibial rotation is Linearly Associated with Tibial Tubercle-Trochlear Groove Distance: A Cadaveric Study

OBJECTIVES

A tibial tubercle-trochlear groove (TT-TG) distance of 20 millimeters (mm) is typically used when determining whether tibial tubercle medialization is performed for surgical treatment of patellar instability. Without knowledge of the variability of an individual's TT-TG distance influenced by through-the-knee femorotibial rotation, the use of a specific TT-TG distance during pre-operative planning for patellar instability may lead to incorrect decisions on the use of tibial tubercle medializtion. We hypothesized that knee joint IE rotation is related to the TT-TG distance.

METHODS

Eight independent human cadaveric knee specimens (age: 32 ± 6 years; 4 males, 4 females) were utilized. A robotic manipulator (ZX165U, Kawasaki Robotics, Wixom, MI, USA) instrumented with a universal force/moment sensor was used to determine knee joint IE rotation under applied moments of ±5 newton-meters (Nm) at full extension. Two independent reviewers selected the trochlear groove and tibial tuberosity points on computerized tomography (CT) images of each specimen to define TT-TG. To determine the influence of knee joint IE rotation on TT-TG distance, three-dimensional (3D) models generated from CT scans were registered to tibiofemoral kinematics. Linear regression was performed to determine the relationship between knee joint IE rotation and TT-TG distance. The regression coefficient and standard error of measurement (α = 0.05), and coefficient of determination (r2) were reported.

RESULTS

At 0° of rotation, the mean TT-TG distance was 14.2 ± 5.0 mm. Knee joint IE rotation averaged 23.0 ± 4.2°. For every degree of knee joint IE rotation, TT-TG distance changed by 0.52 mm.

CONCLUSION

TT-TG distance was linearly dependent on knee joint IE rotation changing by 0.52 mm for every degree of knee joint IE rotation. Thus, an offset of IE rotation of 10° would lead to a change in TT-TG distance of 5.2 mm, enough to alter surgical decision-making for/or against tibial tubercle medialization.

LEVEL OF EVIDENCE

IV: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses

BACKGROUND

Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population.

METHODS

All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum.

RESULTS

A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up.

CONCLUSION

Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction.

LEVEL OF EVIDENCE

Level III.

Simultaneous MPFL reconstruction and guided growth result in low rates of recurrent patellofemoral instability

PURPOSE

Implant-mediated guided growth (IMGG) is used to address coronal plane deformity in skeletally immature patients. Few studies have reported on IMGG and simultaneous medial patellofemoral ligament (MPFL) reconstruction for paediatric patients with concurrent genu valgum and patellofemoral instability (PFI). This study aimed to report on the outcomes of these simultaneous procedures.

MATERIALS AND METHODS

This was a retrospective review of paediatric patients undergoing simultaneous MPFL reconstruction and IMGG between 2016 and 2023. Mechanical lateral distal femoral angle (mLDFA), hip-knee-ankle angle (HKA) and mechanical axis deviation (MAD) were measured on full-length hip-to-ankle plain radiographs. Measurements were taken preoperatively, prior to implant removal and/or at final follow-up with minimum 1-year clinical follow-up.

RESULTS

A total of 25 extremities in 22 patients (10 female) underwent simultaneous IMGG and MPFL reconstruction. The mean age at surgery was 12.6 ± 1.7 years. The mean duration of implant retention was 18.6 ± 11.3 months. Nineteen extremities (76%) underwent implant removal by final follow-up. Preoperative HKA corrected from a mean of 5.8 ± 2.3° to -0.8 ± 4.5° at implant removal or final follow-up (p < 0.001), with mLDFA and MAD similarly improving (both p < 0.001). HKA corrected a mean of 0.7 ± 0.9° per month, while mLDFA and MAD corrected a mean of 0.5 ± 0.6°/month and 2 ± 3 mm/month, respectively. At the time of implant removal or final follow-up, 88% of patients demonstrated alignment within 5° of neutral. Only one extremity experienced subsequent PFI (4%). For 14 patients who underwent implant removal with further imaging at a mean of 7.8 ± 4.9 months, only one patient (7%) had a valgus rebound to an HKA > 5°.

CONCLUSION

Simultaneous MPFL reconstruction and IMGG provided successful correction of lower extremity malalignment with only one recurrence of PFI. This approach is a reliable surgical option for skeletally immature patients with genu valgum and PFI.

LEVEL OF EVIDENCE

Level 4 case series.

Postoperative Strength Differences at Short-Term Follow-Up Vary Based on Autograft Harvest Site After Adolescent Transphyseal Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare the clinical and patient-reported outcomes of adolescent patients who underwent anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) versus hamstring tendon (HT) autograft.

METHODS

This was a retrospective cohort study of adolescent patients aged 18 years or younger treated at a single tertiary care children's hospital who underwent primary transphyseal ACLR using QT or HT between January 2018 and December 2019. All patients had minimum 6-month follow-up. Outcomes included isokinetic strength testing, postoperative Patient-Reported Outcomes Measurement Information System and International Knee Documentation Committee scores, and complications; these were compared between the QT and HT cohorts.

RESULTS

A total of 84 patients (44 HT and 40 QT patients) were included. The QT cohort had a higher proportion of male patients (62.5% vs 34.1%, P = .01). At 3 months, HT patients had a lower hamstring-quadriceps (H/Q) strength ratio (60.7 ± 11.0 vs 79.5 ± 18.6, P < .01) and lower Limb Symmetry Index in flexion (85.6 ± 16.1 vs 95.5 ± 15.7, P = .01) whereas QT patients had a lower Limb Symmetry Index in extension (67.3 ± 9.5 vs 77.4 ± 10.7, P < .01). The H/Q ratio at 6 months was lower in HT patients (59.4 ± 11.5 vs 66.2 ± 7.5, P < .01). Patient-Reported Outcomes Measurement Information System and International Knee Documentation Committee scores were not different at 3 months or latest follow-up. QT patients had more wound issues (20.0% vs 2.3%, P = .01). Patients receiving HT autograft had more ipsilateral knee injuries (18.2% vs 2.5%, P = .03), but there was no difference in graft failure for ACLR using HT versus QT (9.1% vs 2.5%, P = .36).

CONCLUSIONS

There were no differences in patient-reported outcome measures between patients receiving QT autografts and those receiving HT autografts. Patients with QT grafts had more postoperative wound issues but a lower rate of ipsilateral knee complications (graft failure or meniscal tear). Differences in quadriceps and hamstring strength postoperatively compared with the contralateral limb were observed for adolescent ACLR patients receiving QT and HT autografts, respectively. This contributed to higher H/Q ratios seen at 3 and 6 months postoperatively for patients receiving QT autografts.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic study.

Predictors of Persistent Limp Following Proximal Femoral Varus Osteotomy for Perthes Disease

INTRODUCTION

One of the most popular containment procedures for Legg-Calvé-Perthes disease (LCPD) is proximal femur varus osteotomy (PFO). While generally successful in achieving containment, PFO can cause limb length discrepancy, abductor weakness, and (of most concern for families) a persistent limp. While many studies have focused on radiographic outcomes following containment surgery, none have analyzed predictors of this persistent limp. The aim of this study was to determine clinical, radiographic, and surgical risk factors for persistent limp 2 years after PFO in children with LCPD.

METHODS

A retrospective review of a prospectively collected multicenter database was conducted for patients aged 6 to 11 years at disease onset with unilateral early-stage LCPD (Waldenström I) who underwent PFO. Limp status (no, mild, and severe), age, BMI, and pain scores were obtained at initial presentation, 3-month, and 2-year postoperative visits. Preoperative and follow-up radiographs were used to measure traditional morphologic hip metrics including acetabular index (AI), lateral center-edge angle (LCEA), and femoral neck-shaft angle (NSA). Univariate analysis as well as multivariate logistic regression models were used to analyze factors associated with mild and severe limp at the 2-year visit.

RESULTS

A total of 95 patients met the inclusion criteria, and of these 50 patients underwent concomitant greater trochanter apophysiodesis (GTA) at the time of PFO. At the 2-year visit, there were 38 patients (40%) with a mild or severe limp. Multivariate logistic regression revealed no significant radiographic factors associated with a persistent limp. However, lower 2-year BMI and undergoing GTA were associated with decreased rates of persistent limp regardless of age (P<0.05). When stratifying by age of disease onset, apophysiodesis appeared to be protective against any severity of limp in patients aged 6 to 8 years old (P= 0.03), but not in patients 8 years or older (P= 0.49).

CONCLUSIONS

Persistent limp following PFO is a frustrating problem that was seen in 40% of patients at 2 years. However, lower follow-up BMI and performing a greater trochanter apophysiodesis, particularly in patients younger than 8 years of age, correlated with a lower risk of postoperative limp.

Measurement of TT-TG can change with sequential MRIs due to variations in tibiofemoral rotation in patellofemoral instability patients

PURPOSE

There are various anatomic risk factors for patellofemoral instability (PFI) that help guide surgical treatment, including the tibial tubercle to trochlear groove (TT-TG) distance. However, no study has analysed the temporal changes in TT-TG prior to surgical intervention. This study sought to understand the variations in TT-TG over time for pediatric patients suffering from PFI prior to surgical intervention. The authors hypothesised that the TT-TG would substantially change between time points.

METHODS

Patients undergoing medial patellofemoral ligament (MPFL) reconstruction between 2014 and 2019 by one of two fellowship-trained orthopaedic surgeons were identified. Patients were included if they had two preoperative magnetic resonance imaging (MRI) performed on the same knee within 7.5 months of each other prior to any surgical intervention and had an initial TT-TG greater than 10 mm.

RESULTS

After considering 251 patients for inclusion, 21 patients met the final inclusion criteria. The mean age was 14.5 ± 2.5 years and 61.9% were female. TT-TG was initially noted to be 15.1 ± 1.8 mm. At mean time after sequential MRIs of 5.0 ± 1.9 months, TT-TG was noted to be 16.7 ± 3.2 mm. The differences between initial and subsequent TT-TG ranged from a 21.2% decrease to a 61.1% increase, with a mean difference of an 11.3% increase. Comparison between initial and subsequent TT-TG values demonstrated a significant difference (p = 0.017). Change in tibiofemoral rotation ranged from -9.2° to 7.5°. When comparing the change in TT-TG to change in tibiofemoral rotation, a significant correlation was found (p = 0.019).

CONCLUSION

Despite only a mean time between MRIs of 5 months, variations in TT-TG ranged from a decrease of 21.2% to an increase of 61.1%. The significant relationship between the changes in TT-TG and changes in tibiofemoral rotation between MRIs suggest that TT-TG measurements may vary due to variations in tibiofemoral rotation at the time of individual MRIs.

LEVEL OF EVIDENCE

Level IV.

Back to Basics: Pediatric Casting Techniques, Pearls, and Pitfalls

Cast application is a critical portion of pediatric orthopaedic surgery training and is being performed by a growing number of non-orthopaedic clinicians including primary care physicians and advanced practice providers (APPs). Given the tremendous remodeling potential of pediatric fractures, correct cast placement often serves as the definitive treatment in this age population as long as alignment is maintained. Proper cast application technique is typically taught through direct supervision from more senior clinicians, with little literature and few resources available for providers to review during the learning process. Given the myriad complications that can result from cast application or removal, including pressure sores and cast saw burns, a thorough review of proper cast technique is warranted. This review and technique guide attempts to illustrate appropriate upper and lower extremity fiberglass cast application (and waterproof casts), including pearls and pitfalls of cast placement. This basic guide may serve as a resource for all orthopaedic and non-orthopaedicproviders, including residents, APPs, and medical students in training. Level of Evidence: IV.

Factors Influencing Why Children and Their Families Choose Surgery for Ganglion Cysts

PURPOSE

Ganglion cysts of the hand/wrist are frequently managed without surgery but can be treated with surgical excision if there is pain or dysfunction. No studies have examined the specific factors predictive of surgical treatment for pediatric patients.

METHODS

This was a study of pediatric patients (≤18 years) with ganglion cysts of the hand/wrist seen between 2017 and 2019 at 2 institutions. Baseline demographic data were collected in addition to cyst characteristics, Wong-Baker pain scores, and Patient-Reported Outcomes Measurement Information System scores (pain, depression, upper extremity function, anxiety). Multivariable regression was used to determine the factors predictive of surgical intervention at ≥6 months of eligible follow-up.

RESULTS

A total of 167 patients with a mean age of 10.1 ± 5.3 years were included for analysis. Forty-three (25.7%) underwent surgical excision of their ganglion cyst at means of 2.3 months after the initial visit and 12.6 months after cyst appearance. Sex and cyst location were similar between cohorts. Surgical patients were older (12.1 vs 9.4 years, respectively) and presented to the clinic later after an appearance (10.9 vs 6.5 months, respectively) compared to nonsurgical patients. Surgical patients also had higher pain scores at presentation (median, 3 vs 0, respectively). Cysts receiving surgery were larger than those without surgery (81.4% vs 55.3% >1 cm, respectively). Pain interference Patient-Reported Outcomes Measurement Information System scores were higher in the surgical than the nonsurgical group (45.2 vs 39.6, respectively). In a multivariable analysis, pain scores ≥4 (odds ratio, 3.4) were predictive of surgery for patients ≥3 years, whereas older age (odds ratio, 1.1) and a cyst size >1 cm (odds ratio, 3.3) predicted surgery across all patients.

CONCLUSIONS

Pediatric patients with ganglion cysts who initially present at older ages with moderate/severe pain scores and larger cysts are more likely to ultimately choose surgical excision. Surgeons may observe a preference for earlier surgery in this subset of patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Glass Ceiling in Hand Surgery: Publication Trends by Gender

BACKGROUND

Women are frequently underrepresented across surgical subspecialties and may face barriers to academic advancement. Abstracts presented at American Society for Surgery of the Hand annual meeting (ASSH-AM) highlight some of the top research in hand surgery. We sought to explore differences in abstract characteristics and publication rates based on senior author gender.Though there have been increasing efforts at inclusivity in orthopedic and plastic surgery, women face several barriers to entering the field, publish less frequently, and are underrepresented in leadership positions. Understanding the stages at which discrepancies in research productivity exist may help to address these challenges.

METHODS

Abstracts from the 2010-2017 ASSH-AMs were reviewed to determine basic characteristics. Author gender was determined through both a search of institutional websites for gender-specific pronouns and inference of gender based on first name. Subsequent full manuscript publications corresponding to the abstracts were identified through a systematic search of PubMed and Google Scholar.

RESULTS

A total of 560/620 (90.3%) abstracts from 2010-2017 had an identifiable senior author gender (14.5% female). No differences were noted between male- and female-authored abstracts regarding study design including sample size or level of evidence. Female senior authors were more likely than males to author abstracts focused on pediatrics (19.8% vs 9.4%, p=0.01) and were more likely to collaborate with female first authors (41.3% vs 20.0%, p<0.01). Abstract publication rates were lower for female senior authors versus male senior authors (61.7% vs 74.5%, p=0.02).

CONCLUSION

The number of abstracts with female senior authors had similar representation to the membership proportion of women in the ASSH. There were few differences in abstract characteristics based on senior author gender, though senior authors tend to collaborate with investigators of the same gender. Abstracts authored by females were published 13% less frequently overall, meriting further exploration. Level of Evidence: III.

Clinical Presentation and Characteristics of Hand and Wrist Ganglion Cysts in Children

PURPOSE

Ganglion cysts are the most common mass of the hand or wrist. In adults, ganglions have a female predilection and are commonly located in the dorsal wrist. However, their presentation in children has not been well reported. This investigation sought to describe the presentation of pediatric ganglion cysts in a prospective cohort.

METHODS

A multicenter prospective investigation of children (aged ≤18 years) who presented with ganglion cysts of the hand or wrist was conducted between 2017 and 2019. The data collected included age, sex, cyst location, hand dominance, pain, and patient-reported outcomes measurement information system (PROMIS) scores for upper-extremity (UE) function. The patients were divided into cohorts based on age, cyst location, and cyst size. Multivariable analyses were performed to identify factors predictive of worse UE function and higher pain scores.

RESULTS

A total of 173 patients with a mean age of 10.1 ± 5.3 years and female-to-male ratio of 1.4:1 were enrolled. The dorsal wrist was the most commonly affected (49.7%), followed by the volar wrist (26.6%) and flexor tendon sheath (18.5%). In older patients, dorsal wrist ganglions were more common than tendon sheath cysts (11.9 ± 4.1 years vs 6.2 ± 5.8 years) and were larger (86.7% were >1 cm) than cysts in other locations (34.5% were >1 cm). Patients aged >10 years reported higher pain scores, with 21.5% of older patients reporting moderate/severe pain scores versus 5.0% of younger children. This cohort of patients had an average PROMIS UE function score of 47.4 ± 9.5, and lower PROMIS scores were associated with higher pain scores.

CONCLUSIONS

Ganglions in pediatric populations, which most commonly affect the dorsal wrist, demonstrate a female predilection. In younger children, cysts are smaller and more often involve the volar wrist or flexor tendon sheath. Older children report higher pain scores. Pediatric ganglion cysts do not appear to result in a clinically meaningful decrease in UE function.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Orthopaedic Surgery Residency Program Social Media Presence During the COVID-19 Pandemic

In light of away rotation and in-person interview cancellations for the 2020 to 2021 application cycle, social media has become a popular tool for orthopaedic surgery residency programs to highlight their strengths, curricula, and social life to prospective applicants. The authors sought to explore the proliferation and utilization of 3 popular social media platforms by both orthopaedic surgery departments and residencies.

METHODS

Orthopaedic surgery departmental and residency program social media accounts and their creation dates across Facebook, Twitter, and Instagram were identified using a standardized search methodology. Residency Instagram accounts were further evaluated for the number of posts, followers, likes, and comments. Both departments and residency programs were cohorted by affiliation with a US News &World Report (USNWR) top 50 American hospital for orthopaedics or by status as a Doximity top 20 program based on reputation.

RESULTS

Across a total of 192 residency programs included for analysis, Instagram was the most popular social media platform (61.5%), followed by Twitter (19.8%) and Facebook (10.4%). Conversely, orthopaedic departments more frequently used Facebook (33.9%) and Twitter (28.1%) over Instagram (17.2%). Of the 118 residency Instagram accounts, 102 (86.4%) were created after the onset of the COVID-19 pandemic. Larger residency programs (≥6 spots/year) and those programs in the Doximity top 20 or affiliated with USNWR top 50 orthopaedic hospitals had a greater number of followers as well as likes and comments per post (p < 0.05 for all).

CONCLUSIONS

Given the recruitment challenges faced by residency programs because of the COVID-19 pandemic, Instagram has rapidly become a prominent platform for attracting orthopaedic surgery applicants. These accounts have a large number of followers, particularly for residency programs with higher Doximity reputation rankings.

Outcomes and Complications in Management of Congenital Myopathy Early-Onset Scoliosis

BACKGROUND

Congenital myopathies (CMs) are complex conditions often associated with early-onset scoliosis (EOS). The purpose of this study was to investigate radiographic outcomes in CM patients undergoing EOS instrumentation as well as complications. Secondarily, we sought to compare these patients to a population with higher prevalence, cerebral palsy (CP) EOS patients.

METHODS

This is a retrospective study of a prospectively collected multicenter registry. The registry was queried for EOS patients with growth-sparing instrumentation (vertical expandable prosthetic titanium ribs, magnetically controlled growing rods, traditional growing rod, or Shilla) and a CM or CP diagnosis with minimum 2 years follow-up. Outcomes included major curve magnitude, T1-S1 height, kyphosis, and complications.

RESULTS

Sixteen patients with CM were included. Six (37.5%) children with CM experienced 11 complications by 2 years. Mean major curve magnitude for CM patients was improved postoperatively and maintained at 2 years (P<0.01), with no significant increase in T1-S1 height or maximum kyphosis(P>0.05). Ninety-seven patients with CP EOS were included as a comparative cohort. Fewer CP patients required baseline respiratory support compared with CM patients (20.0% vs. 92.9%, P<0.01). Fifty-four (55.7%) CP patients experienced a total of 105 complications at 2 years. There was no evidence that the risk of complication or radiographic outcomes differs between cohorts at 2 years, though CP EOS patients experienced significant improvement in all measurements at 2 years.

CONCLUSIONS

EOS CM children face a high risk of complication after growing instrumentation, with similar curve correction and risk of complication to CP patients.

LEVEL OF EVIDENCE

Level III.

Hip Morphology in Early-stage LCPD: Is There an Argument for Anatomic-specific Containment?

BACKGROUND

Early containment surgery has become increasingly popular in Legg-Calvé-Perthes Disease (LCPD), especially for older children. These procedures treat the proximal femur, the acetabulum, or both, and most surgeons endorse the same surgical option regardless of an individual patient's anatomy. This "one-surgery-fits-all" approach fails to consider potential variations in baseline anatomy that may make one option more sensible than another. We sought to describe hip morphology in a large series of children with newly diagnosed LCPD, hypothesizing that variation in anatomy may support the concept of anatomic-specific containment.

METHODS

A retrospective review of a prospectively collected multicenter database was conducted for patients aged 6 to 11 at diagnosis. To assess anatomy before significant morphologic changes secondary to the disease itself, only patients in Waldenström stages IA/IB were included. Standard hip radiographic measurements including acetabular index, lateral center-edge angle, proximal femoral neck-shaft angle (NSA), articulotrochanteric quartiles, and extrusion index (EI) were made on printed anteroposterior pelvis radiographs. Age-specific percentiles were calculated for these measures using published norms. Significant outliers (≤10th/≥90th percentile) were reported where applicable.

RESULTS

A total of 168 patients with mean age at diagnosis of 8.0±1.3 years met inclusion criteria (81.5% male). Mean acetabular index for the entire cohort was 16.8±4.1 degrees; 58 hips (34.5%) were significantly dysplastic compared with normative data. Mean lateral center-edge angle was 15.9±5.2 degrees at diagnosis; 110 (65.5%) were ≤10th percentile indicating dysplasia (by this metric). Mean NSA overall was 136.5±7.0 degrees. Fifty-one (30.4%) and 20 (11.9%) hips were significantly varus (≤10th percentile) or valgus (≥90th percentile), respectively. Thirty-five hips (20.8%) were the third articulo-trochanteric quartiles or higher suggesting a higher-riding trochanter at baseline. Mean EI was 15.5%±9.0%, while 63 patients (37.5%) had an EI ≥20%.

CONCLUSIONS

The present study finds significant variation in baseline anatomy in children with early-stage LCPD, including a high prevalence of coexisting acetabular dysplasia as well as high/low NSAs. These variations suggest that the "one-surgery-fits-all" approach may lack specificity for a particular patient; a potentially wiser option may be an anatomic-specific containment operation (eg, acetabular-sided osteotomy for coexisting dysplasia, varus femoral osteotomy for valgus NSA).

LEVEL OF EVIDENCE

Level IV.

A seat at the table: an invitation to the SRS podium via the study group

PURPOSE

The SRS annual meeting (SRS-AM) represents the pinnacle of research in the field of spinal deformity. Spine surgery research was historically based on single-surgeon experience, but an increasing number of abstracts presented at SRS-AM are conducted by multicenter study groups, which may have improved the quality of literature available to surgeons. We sought to determine the proportion of SRS-AM podium presentations (PP) resulting from study groups over a 15-year period.

METHODS

1874 PP from the 2005-2019 SRS-AM were reviewed to determine if they resulted from a study group or multicenter collaboration. Abstracts were also classified as pediatric- or adult-focused. Pearson correlations were calculated to analyze changes in the proportion of study group or multicenter PP.

RESULTS

The number of SRS PP increased from 102 to 171 from 2005 to 2019. 381 (20.3%) PP were identified as a study group product, while 536 (28.6%) resulted from multicenter collaboration. The proportion of study group PP increased by 0.9% annually from 8.8 to 26.9% (r² = 0.44, p = 0.007), while multicenter PP increased by 1.2% annually from 11.8 to 40.9% (r² = 0.51, p = 0.003). A greater proportion of study group PP were level of evidence I or II studies compared to those not resulting from the work of study groups (53.8 vs 19.3%, p < 0.001).

CONCLUSION

SRS-AM PP resulting from research study groups and multicenter collaborations increased over threefold from 2005 to 2019. Spine surgeons are taking a more proactive approach to produce more generalizable research with higher level of evidence through multicenter study groups, allowing them to make more informed decisions to ultimately improve surgical outcomes for patients.

LEVEL OF EVIDENCE

V.

Anterior Cruciate Ligament Injury Incidence in Adolescent Athletes: A Systematic Review and Meta-analysis

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries among adolescent athletes is steadily increasing. Identification of the highest risk sports for ACL injuries by sex and competitive setting (ie, practice vs match) is important for targeting injury prevention programs.

PURPOSE

To identify the risk of ACL injuries in adolescent athletes by sport, sex, and setting across a variety of common US and international sports.

STUDY DESIGN

Meta-analysis.

METHODS

Essentially, 3 online databases (PubMed, Embase, and Cochrane Library) were searched for all studies of ACL injuries per athlete-exposure (AE) or hours of exposure in adolescent athletes. Injuries were then pooled and incidence rates (IRs) reported per 1000 AEs or hours of exposure, with the relative risk (RR) of injuries calculated for sex-comparable sports. IRs per competitive setting (match vs practice) were also calculated.

RESULTS

A total of 1235 ACL injuries over 17,824,251 AEs were identified (IR, 0.069 [95% CI, 0.065-0.074]), with 586 of these injuries in girls across 6,986,683 AEs (IR, 0.084 [95% CI, 0.077-0.091]) versus 649 injuries in boys over 10,837,568 AEs (IR, 0.060 [95% CI, 0.055-0.065]). Girls had a higher overall rate of ACL injuries (RR, 1.40 [95% CI, 1.25-1.57]), with the most disproportionate risk observed in basketball (RR, 4.14 [95% CI, 2.98-5.76]). The risk of ACL injuries by sex was highest in girls' soccer (IR, 0.166 [95% CI, 0.146-0.189]) and boys' football (IR, 0.101 [95% CI, 0.092-0.111]). ACL injuries were over 8 (RR, 8.54 [95% CI, 6.46-11.30]) and 6 (RR, 6.85 [95% CI, 5.52-8.49]) times more likely to occur in a match versus a practice setting for female and male athletes, respectively.

CONCLUSION

The risk of ACL injuries overall approached nearly 1 per 10,000 AEs for female athletes, who were almost 1.5 times as likely as male athletes to suffer an ACL injury across all adolescent sports. A multisport female athlete was estimated to have a nearly 10% risk of ACL injuries over her entire high school or secondary school career. Specifically, male and female adolescents playing soccer, basketball, lacrosse, and football appeared at particular risk of injuries, a finding that can be used to target an injury intervention.

Is There a Benefit to Weaning Pavlik Harness Treatment in Infantile DDH?

BACKGROUND

Following successful treatment of developmental hip dysplasia with a Pavlik harness, controversy exists over the benefit of continued harness use for an additional "weaning" period beyond ultrasonographic normalization versus simply terminating treatment. Although practitioners are often dogmatic in their beliefs, there is little literature to support the superiority of 1 protocol over the other. The purpose of this study was to compare the radiographic outcomes of 2 cohorts of infants with developmental hip dysplasia treated with Pavlik harness, 1 with a weaning protocol and 1 without.

METHODS

This was a comparative review of patients with dislocated/reducible hips and stable dysplasia from 2 centers. All patients had pretreatment ultrasounds, and all started harness treatment before 3 months of age. On the basis of power analysis, a sufficient cohort of hips were matched based on clinical examination, age at initiation, initial α angle, and initial percent femoral head coverage. Patients from institution W (weaned) were weaned following ultrasonographic normalization, whereas those from institution NW (not weaned) immediately ceased treatment. The primary outcome was the acetabular index at 1 year of age.

RESULTS

In total, 16 dislocated/reducible and 16 stable dysplastic hips were matched at each center (64 total hips in 53 patients). Initial α angle and initial femoral head coverage were not different between cohorts for either stable dysplasia (P=0.59, 0.81) or dislocated/reducible hips (P=0.67, 0.70), respectively. As expected, weaned hips were treated for significantly longer in both the stable dysplasia (1540.4 vs. 1066.3 h, P<0.01), and dislocated/reducible cohorts (1596.6 vs. 1362.5 h, P=0.01). Despite this, we found no significant difference in the acetabular index at 1 year in either cohort (22.8 vs. 23.1 degrees, P=0.84 for stable dysplasia; 23.9 vs. 24.8 degrees, P=0.32 for Ortolani positive).

CONCLUSIONS

Despite greater total harness time, infants treated with additional Pavlik weaning did not demonstrate significantly different radiographic results at 1 year of age compared with those who were not weaned. However, differences in follow-up protocols between centers support the need for a more rigorous randomized controlled trial.

LEVEL OF EVIDENCE

Level III.

Sinister! The high pre-op left shoulder is less likely to be radiographically balanced at 2 years post-op

PURPOSE

AIS patients consider shoulder balance an important cosmetic outcome after surgery. We examined the impact of preoperative left shoulder elevation (LSE) and choice of upper instrumented vertebra (UIV) on postoperative shoulder imbalance (PostSI).

METHODS

This was a retrospective cohort study utilizing a prospective AIS database. Patients had Lenke type 1-4 curves and preoperative shoulder height ≥ 1.0 cm. Patients with preoperative LSE and right shoulder elevation (RSE) were compared. Shoulder height difference < 1 cm was considered 'mild', 1-2 cm was 'moderate', and ≥ 2.0 cm was 'severe'.

RESULTS

407 patients had ≥ 1.0 cm imbalance preoperatively, with 88 (21.6%) LSE. There were no differences in gender (p = 0.855) or age (p = 0.477). Patients with LSE more frequently had Lenke type 2 curves (43.2% vs 16.3%, p < 0.001), while preoperative RSE averaged 1.9 ± 0.9 cm versus 1.6 ± 0.5 cm for LSE (p < 0.001). Those with LSE more often had severe PostSI at 2 years (30.7% vs 5.0%, p < 0.001), and only 26.1% of patients with severe preoperative LSE corrected to mild. In contrast, most patients with RSE had mild PostSI regardless of initial imbalance. When examining only LSE patients, there was no difference in preoperative SH by final UIV (p = 0.101). Further, UIV choice did not impact the proportion of severely unbalanced patients postoperatively (p = 0.446). A PTC > 34.5° was predictive of PostSI ≥ 2.0 cm for patients with preoperative LSE.

CONCLUSION

AIS patients with preoperative LSE are less likely to achieve level shoulders postoperatively. Choice of higher UIV did not affect postoperative shoulder imbalance in this cohort. A PTC > 34.5° was predictive of severe PostSI in patients with preoperative LSE.

LEVEL OF EVIDENCE

II.

Decreased Prescribing of Postoperative Opioids in Pediatric ACL Reconstruction: Treatment Trends at a Single Center

Background:

Anterior cruciate ligament (ACL) injury is common in the pediatric population. Pain control after ACL reconstruction (ACLR) presents a unique challenge due to age and early rehabilitation needs. Pain management practices are believed to have evolved in recent years to limit unnecessary exposure to risks associated with opioid use in this vulnerable population.

Purpose:

To describe trends in postoperative opioid prescribing and assess factors including obtaining consent for opioid prescribing for minors that may have mitigated excessive prescription of opioids.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This is a retrospective review of a consecutive series of pediatric patients (<18 years) undergoing primary ACLR within an urban academic hospital system over a 5-year period (2014-2018). The study period included the gradual introduction of preoperative consenting for opioid use in minors as mandated by state law in 2016. Patient characteristics, surgical details, presence of a signed consent form to prescribe opioid medications, prescribed postoperative medications, prescriber, and indicators of inadequate pain control were collected. Univariate and multivariate analyses were performed to determine factors associated with reduced postoperative opioid prescribing.

Results:

This study included 687 patients with a mean age of 15.1 ± 1.9 years, with less than one-third of patients having preoperative consent forms to prescribe opioid medications. Postoperative prescribing trends demonstrated a decline in the number of opioid doses provided and increased utilization of nonopioid medications. Patients who received preoperative opioid counseling and signed a consent form were prescribed fewer opioids and had a smaller number of unscheduled contacts for poorly controlled pain. Univariate analyses identified multiple predictors of the number of opioid doses prescribed postoperatively. Obtaining preoperative consent to prescribe opioids and ambulatory surgery center location were found to be independent predictors of prescribed doses in the multivariate analysis.

Conclusion:

The quantity of opioid medication prescribed for pain management after pediatric ACLR at our institution has declined in recent years. This appears to be, in part, related to state-mandated preoperative counseling about opioid use, signing of a consent form by the parent(s) or guardian(s) to prescribe opioids to minors, and encouragement toward the use of nonopioid medications when possible. Preoperative opioid use discussions in the pediatric population may be useful in reducing opioid overprescription and utilization in this population.

Do Pediatric Patients With Anterior Cruciate Ligament Tears Have a Higher Rate of Familial Anterior Cruciate Ligament Injury?

Background:

Several studies have examined the anterior cruciate ligament (ACL) injury history among relatives of patients undergoing ACL reconstruction (ACLR), but they have primarily analyzed adults with variable results.

Hypothesis:

We hypothesized that he rate of familial ACL injuries among pediatric patients with ACL tears would be greater than that among pediatric patients with uninjured knees.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Pediatric patients (≤18 years of age) who underwent ACLR between January 2009 and May 2016 were contacted to complete a questionnaire on subsequent complications and family history of ACL tears. A control cohort was recruited from children with uninjured knees seen in the concussion clinic of our institution. Binary logistic regression was used to determine the factors predictive of having a familial ACL tear history or complications.

Results:

Overall, 450 pediatric patients with primary ACL tears were included. Age at the time of surgery was 14.9 ± 2.2 years with a follow-up of 4.3 ± 2.1 years. When compared with 267 control patients, those with an ACL tear reported a higher rate of first-degree relatives with an ACL injury history (25.1% vs 12.0%; P < .001). In multivariate analysis, children with ACL injury had nearly 3 times (odds ratio [OR], 2.7) higher odds of having a first-degree relative with an ACL tear (95% CI, 1.7-4.2; P < .001). Patients were stratified by the number of first-degree relatives with ACL tears: no relatives, 1 relative, or ≥2 relatives. Children with ≥2 first-degree relatives were more likely to sustain a postoperative graft failure (OR, 5.1; 95% CI 1.7-15.2; P = .003) or a complication requiring surgical intervention (OR, 7.5; 95% CI, 2.6-22.0; P < .001).

Conclusion:

A family history of ACL injury is more likely in pediatric patients with ACL tears than in uninjured children. Further, patients undergoing primary ACLR as well as a strong family history of ACL tears are more likely to sustain a postoperative graft rupture or complication requiring surgery.

Do Year-Out Programs Make Medical Students More Competitive Candidates for Orthopedic Surgery Residencies?

OBJECTIVE

As orthopedic surgery residency programs are becoming more competitive, medical students interested in orthopedics are increasingly completing "year-out" programs. This study sought to evaluate student and faculty perceptions of these programs.

DESIGN

A survey evaluating baseline characteristics was disseminated to directors of year-out programs identified through postings on the orthopedics forum, Orthogate.org. A second survey was sent to all program directors (PDs) of accredited US orthopedic residencies, while a final survey was distributed to participants identified by year-out PDs.

SETTING

Ninety-six orthopedic year-out programs at 56 institutions were contacted.

PARTICIPANTS

Twenty-six year-out programs, 72 PDs of ACGME-accredited orthopedic residencies, and 34 year-out participants from 6 programs completed our questionnaires.

RESULTS

73.1% (19) year-out program provided funding to participants, averaging $30,368. 84.6% (22) reported >75% match rates into orthopedics for participants. 65.4% (17) of programs selected students between their MS3/MS4 school years. 4.2% (3) of residency PDs agreed or strongly agreed that year-out programs were important factors for consideration in residency programs, compared with 82.4% (28) of year-out participants and 69.2% (18) of year-out PDs (p < 0.001). 58.8% (2) of year-out participants cited completion of a year-out for improving the chance of matching into any orthopedic residency, while 85.3% (29) wanted to be more competitive for top programs. The average Step 1 score was 248, which was insignificantly different from the national average for matched orthopedic applicants.

CONCLUSIONS

Orthopedic year-out programs have dramatically increased in number over the last 20 years. Most of these programs are funded, 1-year clinical research fellowships with relative match success for participants pursuing orthopedic residencies. While year-out PDs and students consider participation in such programs to be an important factor for residency applications, and often participate in them in order to improve their competitiveness for matching at desired programs, residency PDs overall hold different views.

Four Risk Factors for Arthrofibrosis in Tibial Spine Fractures: A National 10-Site Multicenter Study

BACKGROUND

Tibial spine fractures (TSFs) are relatively rare pediatric injuries. Postoperative arthrofibrosis remains the most common complication, with few studies having examined factors associated with its development.

PURPOSE

To identify risk factors for arthrofibrosis and required MUA or lysis of adhesions in the largest known cohort of patients with TSFs.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a multicenter study of 249 patients ≤18 years old who had a TSF between January 2000 and February 2019. Patients were separated into cohorts based on whether they developed arthrofibrosis, defined as a 10° deficit in extension and/or 25° deficit in flexion at postoperative 3 months or a return to the operating room for manipulation under anesthesia (MUA) and/or lysis of adhesions.

RESULTS

A total of 58 (23.3%) patients developed postoperative arthrofibrosis, with 19 (7.6%) requiring a return to the operating room for MUA. Patients with arthrofibrosis were younger (mean ± SD, 11.3 ± 2.7 vs 12.3 ± 2.8 years; P = .029). They were more likely to have a nonsport, trauma-related injury (65.4% vs 32.1%; P < .001) and a concomitant ACL injury (10.3% vs 1.1%; P = .003). Those with arthrofibrosis had longer operative times (135.0 vs 114.8 minutes; P = .006) and were more likely to have been immobilized in a cast postoperatively (30.4% vs 16.6%; P = .043). In multivariate regression, concomitant anterior cruciate ligament (ACL) injury (odds ratio [OR], 20.0; P = .001), traumatic injury (OR, 3.8; P < .001), age <10 years (OR, 2.2; P = .049), and cast immobilization (OR, 2.4; P = .047) remained significant predictors of arthrofibrosis. Concomitant ACL injury (OR, 7.5; P = .030) was additionally predictive of a required return to the operating room for MUA.

CONCLUSION

Surgeons should be cognizant of arthrofibrosis risk in younger patients with concomitant ACL tears and traumatic injuries not resulting from athletics. Furthermore, postoperative immobilization in a cast should be avoided given the high risk of arthrofibrosis. Concomitant ACL injury is associated with a higher return to the operating room for MUA.

Chondroblastoma of the Navicular Bone: A Report of 2 Pediatric Cases

CASE

Two patients presenting to the clinic with midfoot pain were found to have pathologic fractures through chondroblastomas of the navicular bone. Patient 1 was a 15-year-old boy who experienced multiple recurrences despite more aggressive interventions. Patient 2 was a 13-year-old boy who experienced full recovery after lesion resection.

CONCLUSION

Navicular chondroblastoma is a rare site of presentation, with only 3 documented cases. Given the potential aggressive nature of these lesions with significant cortical destruction and soft-tissue extension, the navicular represents a difficult anatomic location to manage.

An In-Depth Analysis of Graft Rupture and Contralateral Anterior Cruciate Ligament Rupture Rates After Pediatric Anterior Cruciate Ligament Reconstruction

BACKGROUND

Reported rates of graft rupture and contralateral anterior cruciate ligament (ACL) rupture after ACL reconstruction (ACLR) are higher among pediatric patients than adults. Previous series may have underestimated postoperative event risk because of small sample sizes and high proportions of dropouts.

PURPOSE

To calculate rates of graft rupture and contralateral ACL rupture after ACLR in a large pediatric series.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

ACLRs performed in our tertiary care children's hospital system over a period of >7 years were identified through billing review. Cases were sorted based on operative technique, with all-epiphyseal ACLRs considered separately. Transphyseal ACLRs were divided into 2 groups based on patient age, with a cutoff of 16 years. Clinic follow-up data as well as prospectively collected survey data were used to note graft rupture and contralateral ACL rupture events. Rates of graft rupture and contralateral ACL rupture were calculated using Kaplan-Meier survival analysis.

RESULTS

The final data set included 996 patients. A total of 161 patients underwent all-epiphyseal ACLR. Of the remaining transphyseal surgeries, 504 patients were <16 years of age at the time of surgery and 331 were ≥16 years. The 4-year cumulative rate of graft rupture via Kaplan-Meier survival analysis was 19.7% among all patients. The rate was 18.2% among all-epiphyseal ACLRs, 21.6% among transphyseal ACLRs in patients <16 years, and 16.4% among transphyseal ACLRs in patients ≥16 years (P = .855). Survival analysis estimated the 4-year cumulative rate of contralateral ACL rupture at 12.0% among all patients: 6.63% among all-epiphyseal ACLRs, 15.7% among transphyseal ACLRs in patients <16 years, and 8.05% among transphyseal ACLRs in patients ≥16 years (P = .093).

CONCLUSION

This is the largest series of pediatric ACLRs yet reported, and it shows that the risks of another ACL injury after first-time ACLR are higher than previously reported. The risk of contralateral ACL rupture was lower than that for graft rupture. Our methods, including prospective follow-up surveys and survival analysis to generate cumulative rate estimates, provide a best-practice example for future case series calculations. Our results provide insight into the postoperative course of pediatric patients undergoing ACLR and are crucial for preoperative patient and family counseling. Understanding these risks may also influence return-to-play decisions.

Effect of drug dose and timing of treatment on the emergence of drug resistance in vivo in a malaria model

BACKGROUND AND OBJECTIVES

There is a significant interest in identifying clinically effective drug treatment regimens that minimize the de novo evolution of antimicrobial resistance in pathogen populations. However, in vivo studies that vary treatment regimens and directly measure drug resistance evolution are rare. Here, we experimentally investigate the role of drug dose and treatment timing on resistance evolution in an animal model.

METHODOLOGY

In a series of experiments, we measured the emergence of atovaquone-resistant mutants of Plasmodium chabaudi in laboratory mice, as a function of dose or timing of treatment (day post-infection) with the antimalarial drug atovaquone.

RESULTS

The likelihood of high-level resistance emergence increased with atovaquone dose. When varying the timing of treatment, treating either very early or late in infection reduced the risk of resistance. When we varied starting inoculum, resistance was more likely at intermediate inoculum sizes, which correlated with the largest population sizes at time of treatment.

CONCLUSIONS AND IMPLICATIONS

(i) Higher doses do not always minimize resistance emergence and can promote the emergence of high-level resistance. (ii) Altering treatment timing affects the risk of resistance emergence, likely due to the size of the population at the time of treatment, although we did not test the effect of immunity whose influence may have been important in the case of late treatment. (iii) Finding the 'right' dose and 'right' time to maximize clinical gains and limit resistance emergence can vary depending on biological context and was non-trivial even in our simplified experiments.

LAY SUMMARY

In a mouse model of malaria, higher drug doses led to increases in drug resistance. The timing of drug treatment also impacted resistance emergence, likely due to the size of the population at the time of treatment.

Which Children Are at Risk for Contralateral Anterior Cruciate Ligament Injury After Ipsilateral Reconstruction?

BACKGROUND

Following anterior cruciate ligament (ACL) reconstruction, children are at significant risk for complications, including contralateral ACL rupture. The purpose of this study is to determine which children are at risk for a contralateral ACL tear after ipsilateral reconstruction.

METHODS

After review of medical records, we contacted patients who underwent primary ACL reconstruction between 2009 and 2016. Patients were included in the study if they were able to provide follow-up data either in person or remotely at least 2 years after surgery. Demographic data, sports participation, and intraoperative findings and techniques were recorded. All patients were also asked to confirm returning to sport information and postoperative complications (including contralateral ACL tear). Univariate analysis consisted of χ and independent samples t tests. Purposeful entry logistic regression was then conducted to control for confounding factors. Kaplan-Meier analysis was performed to assess contralateral ACL survival.

RESULTS

A total of 498 children with average follow-up of 4.3±2.1 years were included in the analysis. The mean age was 15.0±2.3 years and 262 patients (52.6%) were female. Thirty-five subjects (7.0%) sustained a contralateral ACL tear at a mean of 2.7±1.7 years following index reconstruction. Kaplan-Meier analysis revealed the median contralateral ACL survival time to be 8.9 years [95% confidence interval (CI): 8.3, 9.5 y]. In univariate analysis, 11.5% of female patients had a contralateral rupture compared with 2.1% of male patient (P<0.001). Patients with a contralateral tear had a mean age of 14.4±2.0 years compared with 15.1±2.3 years for those without an ACL injury in the opposite knee (P=0.04). After controlling for numerous factors in a multivariate model, female patients had 3.5 times higher odds of sustaining a contralateral ACL tear than male patients (95% CI: 1.1, 10.6; P=0.03). Each year of decreasing age raised the odds of contralateral injury by a factor of 1.3 (95% CI: 1.1, 1.6; P=0.02). Furthermore, children younger than 15 years had 3.1 times higher odds of contralateral rupture than those aged 15 and older (95% CI: 1.3, 7.2; P=0.01).

CONCLUSIONS

After adjusting for confounding factors in a multivariate model, female patients were at increased risk of contralateral ACL tear following ipsilateral reconstruction, as were younger children. Specifically, ACL rupture in the opposite knee was more likely in patients below the age of 15 years.

LEVEL OF EVIDENCE

Level III-prognostic study.

Percutaneous Pinning of Pediatric Proximal Humeral Fractures

Background

Proximal humeral fractures are relatively common in pediatric patients. These injuries are usually treated nonoperatively in younger children or children with minimally displaced fractures. However, closed reduction or open reduction followed by percutaneous pinning is recommended for older children with displaced fractures. Percutaneous pinning has several advantages, but there are limited reports of a safe and reliable surgical technique in the literature.

Description

Patients are positioned in a modified beach-chair position to allow orthogonal imaging. The injured extremity is draped free from the remainder of the body. Closed reduction, which comprises a combination of traction, abduction, and rotation, is attempted. Internal or external rotation may be required, depending on the fracture line and deforming forces. If an anatomic closed reduction cannot be obtained, a block to reduction should be suspected and open reduction should be performed via a deltopectoral approach. Once the fracture is reduced, two 2.5-mm threaded Kirschner wires from the small external fixator set are used to percutaneously fix the fracture. Any small external fixator set can be used, and if not available, individual threaded wires of similar size can be used. Alternatively, Kirschner wires can be advanced to the fracture site prior to reduction and then advanced into the humeral epiphysis once the fracture is reduced. Care is taken to avoid the axillary nerve, which is reliably within 6 cm of the anterolateral aspect of the acromion, and wires are placed distal to this site. Once pin position has been confirmed radiographically, the construct is secured with pin-to-pin clamps to improve rigidity and further decrease the risk of pin migration. A soft dressing and shoulder immobilizer are placed postoperatively. Patients are followed with biweekly radiographs, and pins are removed in the outpatient office or under conscious sedation at 4 weeks. Leaving pins for a longer period may increase the risk of skin irritation and potentially infection.

Alternatives

Alternatives to closed reduction or open reduction and percutaneous pinning include nonoperative management and elastic intramedullary nailing. Nonoperative treatment is a reliable option for most patients. However, it is not suitable for older children with severely displaced fractures because of diminished remodeling potential. Elastic intramedullary nailing is a good option for distal fractures. However, it is not suitable for proximal fractures, and it has been associated with longer operative times and more blood loss than percutaneous pinning. It also requires a second procedure.

Rationale

This procedure allows for anatomic fixation of proximal humeral fractures and provides a rigid construct to maintain reduction. It is not technically challenging, requires limited postoperative immobilization, and decreases the risk of a second general anesthetic.

Use of Continuous Passive Motion Reduces Rates of Arthrofibrosis After Anterior Cruciate Ligament Reconstruction in a Pediatric Population

Joint immobilization after anterior cruciate ligament (ACL) reconstruction may lead to intra-articular adhesions and range of motion deficits. Some practitioners thus advocate for the use of postoperative continuous passive motion (CPM) machine protocols. However, previous studies have failed to show CPM to be effective in increasing postoperative range of motion. Continuous passive motion has, however, been shown to reduce rates of arthrofibrosis requiring manipulation under anesthesia (MUA) in adult populations. To date, there has been no study of the efficacy of CPM after ACL reconstruction in a pediatric population. This was a retrospective cohort study of pediatric patients (age <20 years) who underwent primary ACL reconstruction at an urban tertiary care children's hospital. Clinically significant arthrofibrosis was defined as reduced knee flexion requiring MUA within 6 months of surgery. The final dataset included 163 patients. There was no significant difference between cohorts in range of motion at the 1-week, 1-month, 3-month, and 6-month time points (P=.137, .695, .897, and .339, respectively). The 2 cohorts also did not differ significantly in pain scores at these time points (P=.684, .623, .507, and 1.000, respectively). At 3 and 6 months, neither quadriceps nor hamstrings strength differed significantly between cohorts. Four patients (7.4%) in the no-CPM cohort required MUA for arthrofibrosis within 6 months of surgery, while no patients in the CPM cohort required MUA (P=.023). This suggests that CPM use reduces arthrofibrosis requiring MUA in pediatric patients after ACL reconstruction. Future work may better define the clinical utility and cost-effectiveness of CPM in rehabilitation after these surgeries. [Orthopedics. 2019; 42(1):e81-e85.].

How Does Obesity Impact Pediatric Anterior Cruciate Ligament Reconstruction?

PURPOSE

To assess the relationship of elevated body mass index (BMI) on postoperative outcomes, including graft rupture, contralateral anterior cruciate ligament (ACL) tear, new meniscus injuries, isokinetic strength testing, and range of motion (ROM) in a large group of pediatric patients. We also sought to calculate the risk of graft rupture in overweight patients with small femoral or tibial tunnels. The secondary objective was to evaluate the association between BMI and concurrent meniscus tears and the need for meniscectomy at the time of primary ACL reconstruction.

METHODS

We retrospectively reviewed all pediatric patients undergoing primary ACL reconstruction at our institution. BMI percentile for age was used to categorize children as having normal BMI or being overweight or obese per Centers for Disease Control and Prevention guidelines. Demographic data, intraoperative findings and techniques, postoperative complications (including graft rupture, contralateral ACL tear, and meniscus injuries), ROM, and isokinetic strength testing were recorded. Univariate analysis was followed by stepwise, logistic regression to control for confounders.

RESULTS

Of the 1,056 patients included, 535 (50.7%) were male and 521 were (49.3%) female, with a mean age of 15.1 ± 2.4 years. The average BMI was 23.1 ± 4.7. There were 675 (63.9%) children with normal BMI, 228 (21.6%) who were overweight, and 153 (14.5%) who were obese. In multivariate analysis, children with elevated BMI had a higher rate of concurrent meniscus tears compared with those with normal BMI (76.3% vs 70.2%; P = .02) and 1.6 times higher odds of requiring a meniscectomy (95% confidence interval, 1.2-2.2; P < .01). The 723 patients included in the analysis of postoperative complications had a mean follow-up duration of 26.2 ± 3.3 months Postoperatively, BMI did not impact the rate of graft rupture, contralateral ACL injury, or new meniscus tears. There was no increased risk of graft failure in overweight children with smaller graft size (≤8 mm). There was no clinically relevant difference in postoperative ROM or isokinetic strength testing.

CONCLUSIONS

After ACL rupture, overweight and obese children sustained more overall meniscus tears and more irreparable meniscus tears than those with normal BMI. Graft size did not impact the risk of early graft failure in overweight patients. With an appropriate rehabilitation protocol, there was no increased risk of graft rupture, contralateral ACL injury, or new meniscus tear in early follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Value propositions of mHealth projects

While mHealth holds great potential for addressing global health disparities, a majority of the initiatives never proceed beyond the pilot stage. One fundamental concern is that mHealth projects are seldom designed from the customer's perspective to address their specific problems and/or create appreciable value. A customer-centric view, where direct tangible benefits of interventions are identified and communicated effectively, can drive customer engagement and advance projects toward self-sustaining business models. This article reviews the business models of 234 mHealth projects to identify nine distinct value propositions that solve specific problems for customers. Each of these value propositions is discussed with real-world examples, analyses of their design approaches and business strategies, and common enablers as well as hurdles to surviving past the pilot stage. Furthermore, a deeper analysis of 42 mHealth ventures that have achieved self-sustainability through project revenue provides a host of practical and poignant insights into the design of systems that can fulfil mHealth's promise to address healthcare challenges in the long term.

Existing Infection Facilitates Establishment and Density of Malaria Parasites in Their Mosquito Vector

Very little is known about how vector-borne pathogens interact within their vector and how this impacts transmission. Here we show that mosquitoes can accumulate mixed strain malaria infections after feeding on multiple hosts. We found that parasites have a greater chance of establishing and reach higher densities if another strain is already present in a mosquito. Mixed infections contained more parasites but these larger populations did not have a detectable impact on vector survival. Together these results suggest that mosquitoes taking multiple infective bites may disproportionally contribute to malaria transmission. This will increase rates of mixed infections in vertebrate hosts, with implications for the evolution of parasite virulence and the spread of drug-resistant strains. Moreover, control measures that reduce parasite prevalence in vertebrate hosts will reduce the likelihood of mosquitoes taking multiple infective feeds, and thus disproportionally reduce transmission. More generally, our study shows that the types of strain interactions detected in vertebrate hosts cannot necessarily be extrapolated to vectors.

Utilization and Monetization of Healthcare Data in Developing Countries

In developing countries with fledgling healthcare systems, the efficient deployment of scarce resources is paramount. Comprehensive community health data and machine learning techniques can optimize the allocation of resources to areas, epidemics, or populations most in need of medical aid or services. However, reliable data collection in low-resource settings is challenging due to a wide range of contextual, business-related, communication, and technological factors. Community health workers (CHWs) are trusted community members who deliver basic health education and services to their friends and neighbors. While an increasing number of programs leverage CHWs for last mile data collection, a fundamental challenge to such programs is the lack of tangible incentives for the CHWs. This article describes potential applications of health data in developing countries and reviews the challenges to reliable data collection. Four practical CHW-centric business models that provide incentive and accountability structures to facilitate data collection are presented. Creating and strengthening the data collection infrastructure is a prerequisite for big data scientists, machine learning experts, and public health administrators to ultimately elevate and transform healthcare systems in resource-poor settings.