Validation of a Novel Magnetic Resonance Imaging Classification for Osteochondritis Dissecans of the Knee

BACKGROUND

The novel Kocher classification is a 3-group magnetic resonance imaging (MRI) classification system for osteochondritis dissecans (OCD) of the knee that was shown to have comparable reliability to that of the established 5-group Hefti classification. The purpose of this study was to evaluate the validity and clinical utility of this simplified system as an alternative to the Hefti classification.

METHODS

Demographic data and arthroscopic findings were retrospectively collected from medical and surgical records of 144 consecutive knees in children with arthroscopically diagnosed knee OCD. OCD lesions on preoperative MRIs and surgical reports (serving as the reference standard) were assessed by independent raters and assigned both a Kocher and Hefti classification. Agreement between MRI classification and arthroscopic findings for both systems was assessed using weighted kappa (kw) coefficients. Validation, accuracy, sensitivity, and specificity were measured by comparing a dichotomized Kocher classification for MRI and arthroscopy, and by estimating Cohen kappa (kc) coefficients. Agreement between arthroscopic findings and treatment type was measured using the Spearman correlation coefficient.

RESULTS

Inter-rater reliability between the 2 MRI raters was substantial for the Kocher classification [ka=0.66; 95% confidence interval (CI)=0.56-0.75] and moderate for the Hefti classification (ka=0.57; 95% CI=0.47-0.67). There was no difference detected in the agreement statistics for Kocher versus Hefti classifications (P=0.89). Binary agreement using dichotomized Kocher classifications was worse than the 3-group category classification. When dichotomized, combining Kocher grades 1 and 2 demonstrated moderate agreement (kc=0.41; 95% CI=0.25-0.58), and combining grades 2 and 3 demonstrated fair agreement (kc=0.34; 95% CI=0.21-0.48). There was a strong correlation between arthroscopy-based finding and treatment category for both the Kocher classification (r=0.85; 95% CI=0.80-0.89) and the Hefti classification (r=0.82; 95% CI=0.75-0.86).

CONCLUSION

The validity and clinical utility of the newer 3-group Kocher classification for knee OCD is comparable to that of the well-established 5-group Hefti classification. Both systems help determine lesion stability and characteristics on MRI, which correlate closely to arthroscopic findings. This simplified classification system, with less uncertainty, provides a foundation for further outcomes research to develop an evidence-based algorithm for effective surgical management of OCD lesions of the knee.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Assessment of Skeletal Maturity and Postoperative Growth Disturbance After Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: A Systematic Review

BACKGROUND

Growth disturbance is an uncommon but potentially serious complication after anterior cruciate ligament (ACL) reconstruction in skeletally immature patients.

PURPOSE

To describe how the pediatric ACL literature has assessed preoperative skeletal maturity and the amount of growth remaining and to comprehensively review the incidence, reporting, and monitoring of postoperative growth disturbance.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

This review included studies reporting original research of clinical outcomes of skeletally immature patients after ACL reconstruction. Patient characteristics, surgical techniques, preoperative assessments of skeletal maturity or growth remaining, and postoperative assessments of growth disturbances were extracted.

RESULTS

A total of 100 studies met inclusion criteria. All studies reported chronological age, and 28 studies (28%) assessed skeletal age. A total of 44 studies (44%) used Tanner staging, and 12 studies (12%) obtained standing hip-to-ankle radiographs preoperatively. In total, 42 patients (2.1%) demonstrated a leg length discrepancy (LLD) >10 mm postoperatively, including 9 patients (0.5%) with LLD >20 mm; furthermore, 11 patients (0.6%) with LLD underwent growth modulation. Shortening was the most common deformity overall, but overgrowth was reported more frequently in patients who had undergone all-epiphyseal techniques. Most LLDs involved the femur (83%). A total of 26 patients (1.3%) demonstrated a postoperative angular deformity ≥5°, and 9 of these patients underwent growth modulation. The most common deformities were femoral valgus (41%), tibial recurvatum (33%), and tibial varus (22%). Although standing hip-to-ankle radiographs were the most common radiographic assessment of growth disturbance, most studies inadequately reported the clinical and radiographic methods of assessment for growth disturbance. Additionally, only 35% of studies explicitly followed patients to skeletal maturity.

CONCLUSION

This systematic review described significant variability in the reporting and monitoring of growth-related complications after ACL reconstruction in skeletally immature patients. The incidence of LLD and angular deformity appeared to be low, but the quality of research was not comprehensive enough for accurate assessment.

REGISTRATION

CRD42019136059 (PROSPERO).

Incidence and Risk Factors for Heterotopic Ossification in a Matched Cohort Adolescent Population Undergoing Hip Arthroscopy

BACKGROUND

Heterotopic ossification (HO) is a known complication after hip arthroscopy in adults, positively associated with larger cam resection, male sex, older age, and obesity, and negatively associated with nonsteroidal anti-inflammatory drug (NSAID) use and capsular closure. However, it has not been well-documented in adolescents. The purpose of this study was to determine the incidence and risk factors for the development of HO in adolescent patients undergoing hip arthroscopy.

METHODS

Clinical and operative records from a pediatric institution were queried to identify patients aged 21 years or younger who underwent hip arthroscopy between 2008 and 2018. The 27 cases that developed HO were matched 1:4 on age and sex with 107 controls. The bivariate analysis assessed the relationship between demographic and perioperative factors on the development of HO. Multivariable logistic regression evaluated the association between prophylactic NSAID use (indomethacin 75 mg, 3 wk) and HO, controlling for surgeon and extent of cam resection (change in alpha angle).

RESULTS

Twenty-seven of 595 (4.5%) hips that underwent hip arthroscopy developed HO within 2 years of surgery. Prophylactic indomethacin was not significantly associated with developing HO [30% (8/27), P=0.83], after controlling for surgeon and extent of cam resection-nor were age, sex, and body mass index percentile. Of patients who developed HO, a smaller proportion underwent reoperation for HO excision among those who received prophylactic indomethacin than those who did not [13% (1/8) vs. 63% (12/19), P=0.03].

CONCLUSIONS

The incidence of HO within 2 years of hip arthroscopy in this adolescent population was 4.5%. Although studies in the adult hip arthroscopy population have pointed to a protective role of NSAIDs (eg, indomethacin) in radiographic HO, the effect was less certain in this adolescent sample. Larger studies are important to further evaluate the role of prophylactic NSAIDs and variations in arthroscopic technique in developing HO.

LEVEL OF EVIDENCE

Level III-therapeutic, case-control study.

Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort

BACKGROUND

Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease.

PURPOSE

To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest.

RESULTS

As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases.

CONCLUSION

The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms.

Recovery After ACL Reconstruction in Male Versus Female Adolescents: A Matched, Sex-Based Cohort Analysis of 543 Patients

Background:

Differences in postoperative recovery after anterior cruciate ligament reconstruction (ACLR) between men and women have been demonstrated in the adult population. Sex-based differences have been incompletely investigated in adolescents, which represent the subpopulation most affected by ACL injury.

Purpose/Hypothesis:

The purpose of this study was to compare the 6-month postoperative functional recovery after ACLR between adolescent boys and girls. It was hypothesized that significant differences in postoperative strength, dynamic balance, and functional hop test performance would be seen between the sexes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included in this study were athletes aged 12 to 19 years with closed or closing growth plates who underwent ACLR with hamstring autograft between May 2014 and May 2018 at a single institution. All athletes had undergone strength and functional testing between 5 and 8 months postoperatively. Exclusion criteria were previous knee surgery (contralateral or ipsilateral knee), concomitant injury/surgery other than meniscal tear/repair, allograft supplementation, and incomplete medical records. The limb symmetry index (LSI) for strength (measured with handheld dynamometer), as well as dynamic Y-balance and functional hop test performance, was compared between groups. To account for differences in physical characteristics between the sexes, 1-way between-group multivariate analysis of covariance was used to analyze the data.

Results:

Overall, 543 patients (211 boys, 332 girls) were included. There was no significant difference in age, body mass index, incidence of concomitant meniscal pathology, use of regional anesthesia, or time to functional testing between cohorts. Female athletes demonstrated a statistically significantly greater deficit in quadriceps strength LSI compared with male athletes (boys, +3.4%; girls, –2.3%; P = .011). Both male and female athletes demonstrated 33% hamstring strength deficits, with no statistically significant sex-based differences in dynamic balance or functional hop testing.

Conclusion:

Female athletes demonstrated greater quadriceps strength deficits than male athletes at 6 months after ACLR with hamstring autograft. Severe hamstring strength deficits persisted in both male and female patients at this time point. The correlation of such deficits to risk of ACL retear warrants continued study in the adolescent population and may support a delay in return to sports, which has been suggested in the more recent literature.

Changes in superior displacement, angulation, and shortening in the early phase of healing for completely displaced midshaft clavicle fractures in adolescents: results from a prospective, multicenter study

BACKGROUND

Progressive displacement of diaphyseal clavicle fractures has been observed in adult patients, at times necessitating a change from nonoperative to operative treatment. Whether this occurs in adolescent patients has not been well investigated. The purpose of this study was to assess the rate and extent of progressive clavicle fracture displacement in adolescent patients following injury and during the early stages of healing.

METHODS

This was a multicenter study evaluating prospective data that had previously been collected as part of a larger study evaluating the functional outcomes of adolescent clavicle fractures. A consecutive series of completely displaced diaphyseal clavicle fractures in patients aged 10-18 years treated at 1 of 3 tertiary-care pediatric trauma centers was included; all fractures underwent standardized imaging within 2 weeks of the date of injury and during the course of healing (5-20 weeks after injury). Measurements of clavicle shortening, superior displacement, and angulation were performed using validated techniques. Progressive displacement and/or interval improvement in fracture alignment, as well as the subsequent need for surgical intervention, was noted. Patient demographic and radiographic parameters were assessed as possible risk factors for interval displacement.

RESULTS

One hundred patients met the inclusion criteria. Mean end-to-end shortening, cortex-to-cortex shortening, superior displacement, and angulation at the time of injury were 24 mm, 15 mm, 15 mm, and 7°, respectively. At a mean of 10 weeks after injury, the fracture alignment improved across all 4 measurements for the overall cohort, with mean improvements of 3.5 mm in end-to-end shortening, 3.3 mm in cortex-to-cortex shortening, 2.1 mm in superior displacement, and 2° in angulation. By use of a clinical threshold of a change in shortening or displacement of 10 mm or change in angulation of 10°, 26% of fractures improved, 4% worsened, and 70% remain unchanged. Patients with more severe fractures were more likely to have improved alignment than were patients with less displaced fractures (P < .001). No patient underwent surgical intervention for progressive displacement.

CONCLUSION

Significant early improvements in fracture alignment were observed in a substantial percentage of adolescent patients with completely displaced clavicle fractures. Among the most severely displaced fractures, shortening improved approximately 6 mm and angulation improved approximately 9°. In 4% of cases, increased displacement was observed, but this tended to be mild, and in no cases did it prompt surgical intervention. This finding indicates that the true final deformity after an adolescent clavicle fracture is commonly less than that present at the time of injury.

Early Operative Versus Delayed Operative Versus Nonoperative Treatment of Pediatric and Adolescent Anterior Cruciate Ligament Injuries: A Systematic Review and Meta-analysis

BACKGROUND

Treatment options for pediatric and adolescent anterior cruciate ligament (ACL) injuries include early operative, delayed operative, and nonoperative management. Currently, there is a lack of consensus regarding the optimal treatment for these injuries.

PURPOSE/HYPOTHESIS

The purpose was to determine the optimal treatment strategy for ACL injuries in pediatric and adolescent patients. We hypothesized that (1) early ACL reconstruction results in fewer meniscal tears than delayed reconstruction but yields no difference in knee stability and (2) when compared with nonoperative management, any operative management results in fewer meniscal tears and cartilage injuries, greater knee stability, and higher return-to-sport rates.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic search of databases was performed including PubMed, Embase, and Cochrane Library using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were a pediatric and adolescent patient population (≤19 years old at surgery), the reporting of clinical outcomes after treatment of primary ACL injury, and original scientific research article. Exclusion criteria were revision ACL reconstruction, tibial spine avulsion fracture, case report or small case series (<5 patients), non-English language manuscripts, multiligamentous injuries, and nonclinical studies.

RESULTS

A total of 30 studies containing 50 cohorts and representing 1176 patients met our criteria. With respect to nonoperative treatment, knee instability was observed in 20% to 100%, and return to preinjury level of sports ranged from 6% to 50% at final follow-up. Regarding operative treatment, meta-analysis results favored early ACL reconstruction over delayed reconstruction (>12 weeks) for the presence of any meniscal tear (odds ratio, 0.23; P = .006) and irreparable meniscal tear (odds ratio, 0.31; P = .001). Comparison of any side-to-side differences in KT-1000 arthrometer testing did not favor early or delayed ACL reconstruction in either continuous mean differences (P = .413) or proportion with difference ≥3 mm (P = .181). Return to preinjury level of competition rates for early and delayed ACL reconstruction ranged from 57% to 100%.

CONCLUSION

Delaying ACL reconstruction in pediatric or adolescent patients for >12 weeks significantly increased the risk of meniscal injuries and irreparable meniscal tears; however, early and delayed operative treatment achieved satisfactory knee stability. Nonoperative management resulted in high rates of residual knee instability, increased risk of meniscal tears, and comparatively low rates of return to sports.

Effect of Concomitant Meniscal Tear on Strength and Functional Performance in Young Athletes 6 Months After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft

Background:

The effect of concomitant meniscal tears, and their associated treatment, on strength and functional recovery after anterior cruciate ligament reconstruction (ACLR) has not been adequately investigated in young populations.

Hypothesis:

Concomitant meniscal tears, treated with or without repair, would not adversely affect strength, balance, or functional hop test performance at 6 months postoperatively.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

The authors retrospectively analyzed return-to-sports (RTS) assessments prospectively collected 6 months after ACLR with hamstring autograft in 165 patients ≤25 years of age. Descriptive, surgical, and RTS testing data were analyzed, and subgroups were compared using analysis of covariance models designed to assess the effects of sex, meniscal tear, and meniscal repair on RTS performance.

Results:

Included were 115 female (70%) and 50 male (30%) patients with a mean age of 16.4 years (range, 12.3-25 years). Of these patients, 58% had concomitant meniscal tears (59% lateral, 27% medial, 14% lateral + medial), comprising 53% of the female and 70% of the male patients. The authors treated 61% of the tears with repair, with range of motion (ROM) and weightbearing limitations imposed within the first 6 weeks postoperatively, whereas 39% were treated with partial meniscectomy, rasping, or trephination (no ROM or weightbearing restrictions). The mean deficit in hamstring strength at 6 months postoperatively was significantly greater in the meniscal tear group than in those without a tear (32.3% vs 24.6%; P = .028). The meniscal repair group had greater hamstring strength deficits than the group with meniscectomy, rasping or trephination (34.3% vs 26.2%; P = .023). Performance on dynamic balance and functional hop tests was similar among all meniscus subgroups. There were no sex-based effects on any subgroup comparisons.

Conclusion:

At 6 months postoperatively, both young male and young female patients who underwent ACLR with hamstring autograft demonstrated significant hamstring strength deficits compared with their nonoperative leg. The presence of a meniscal tear and subsequent repair, or its related rehabilitation restrictions, appears to have adverse effects on the postoperative recovery of hamstring strength.

Long-term Minimum 15-Year Follow-up After Lateral Discoid Meniscus Rim Preservation Surgery in Children and Adolescents

BACKGROUND

Discoid meniscus is a congenital variant typically affecting the lateral meniscus of the knee. Historically, surgical intervention when symptomatic consisted of total meniscectomy; however, after degenerative changes were observed, current treatments now focus on rim preservation with arthroscopic saucerization and meniscal repair for instability, when indicated. The purpose of our study was to examine long-term patient-reported outcomes of lateral discoid meniscus (LDM) treated with meniscal-preserving techniques.

METHODS

Ninety-eight patients treated arthroscopically for LDM at a single institution at a minimum of 15 years ago were retrospectively identified and contacted by mailers and telephone to participate. Subjective functional outcomes and patient satisfaction data were collected using a questionnaire that included the validated International Knee Documentation Committee Subjective Knee Evaluation Form, Lysholm Score, Marx Activity Rating Scale, Tegner Activity Score, and Western Ontario and McMaster University Osteoarthritis Index Osteoarthritis Index. Patient and surgical characteristics and patient-reported outcomes were summarized by mean and SD, median and interquartile range (interquartile range), or frequency and percent, as appropriate.

RESULTS

Of the 46 patients contacted (response rate of 46/98 eligible), 25 (54%) completed the questionnaires. The mean (±SD) age at initial surgery was 10.8 (±3.4) and 30.3 (±3.7) years at final follow-up. The mean (±SD) follow-up time from initial surgery was 19.5 (±2.8) years (range, 16 to 27). Patient-reported outcomes included: International Knee Documentation Committee 77.4±17.2, Lysholm 78.6±21, Western Ontario and McMaster University Osteoarthritis Index 7.6±11.3, Tegner Activity 7 (of 10), and Marx Activity Rating Scale 8 (of 10). Eleven (44%) cases underwent subsequent LDM-related surgery on the ipsilateral knee(s). There were no cases of total knee replacement.

CONCLUSIONS

Overall, patient-reported outcomes were favorable at a minimum of 15-year follow-up after rim-preserving saucerization of LDM. While two thirds of patients were satisfied with their surgical outcomes, nearly half of patients underwent revision saucerization with or without meniscal repair. Subsequent long-term follow-up studies with objective outcome measures are important to further elucidate the natural history of LDM and understand how rim-preserving procedures may prevent the development of degenerative processes.

LEVEL OF EVIDENCE

Level IV-case series, prognostic study.

Surgical Management of Medial Discoid Meniscus in Pediatric and Adolescent Patients

BACKGROUND

Medial discoid meniscus (MDM) is an exceedingly rare anatomic abnormality that presents similarly to other meniscal pathologies. Symptomatic MDM is typically managed arthroscopically with mixed short-term and long-term outcomes, although the existing knowledge about MDM is limited. The purpose of this study was to describe the presentation and surgical treatment of MDM in pediatric and adolescent patients.

METHODS

Medical records of 12 knees with MDM in 8 pediatric and adolescent patients treated between 1991 and 2016 were reviewed retrospectively for patient characteristics, clinical manifestations, radiographic findings, operative techniques, and surgical outcomes.

RESULTS

Of the 446 knees diagnosed arthroscopically with discoid menisci, lateral discoid meniscus was noted in 434 knees (97.3%) and MDM was present in 12 knees (2.7%). The MDM series included 8 patients of mean age 13.8 years (range: 7.8 to 19.8), of which 5 were males (63%), and 4 (50%) had bilateral involvement. Of the 11 knees with available clinical records, all cases presented symptomatically (pain, mechanical symptoms); 10 (91%) had concurrent physical exam findings. On intraoperative examination, discoid morphologies were described as complete in 4/8 knees (50%) or incomplete in 4/8 (50%), with associated instability in 6/12 (50%). Meniscal tears were reported in 9 cases (75%)-primarily, horizontal cleavage tears. Saucerization was performed in 11 knees (92%), with medial meniscal repair in 7 (58%), when indicated. Retear of the medial meniscus occurred in 4/11 knees (36%) at a mean of 25.8 months postoperation; 2 knees required revisions. One knee developed arthrofibrosis and underwent arthroscopic lysis of adhesions.

CONCLUSIONS

MDM is a rare diagnosis, representing 3% of all discoid menisci, with a nonspecific clinical manifestation. Operative management of symptomatic MDM typically involves saucerization and meniscal repair, when indicated, for concurrent tears. Symptom resolution is common short-term, but long-term outcomes include recurrent meniscal tears. Subsequent observational studies are important to evaluate long-term outcomes, such as arthritic changes, with the advancement of arthroscopic techniques for meniscal preservation.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Opioid overprescription in adolescents and young adults undergoing hip arthroscopy

Few studies have examined factors related to the increased consumption of opioids after hip arthroscopy in adolescents and young adults. This study sought to determine prescription patterns following hip arthroscopy in this population, and to determine clinical or surgical factors associated with increased post-operative opioid use. Daily post-operative opioid intake was obtained from pain-control logbooks of adolescents and young adults who underwent hip arthroscopy between January 2017 and 2020. Study outcomes were defined as the median total number of opioid tablets consumed, total days opioids were consumed, mean daily opioid consumption and the ratio of opioids prescribed post-operatively to consumed. Clinical and surgical factors were analyzed to determine any association with opioid consumption. Fifty-eight (20%) patients returned completed logbooks. Most patients (73%) were prescribed 30 oxycodone tablets. The median number of tablets consumed was 7 (range 0–41) over a median duration of 7 days (range 1–22). The median ratio of tablets consumed to prescribed was 20%. Increasing patient age at surgery was associated with increased total number of tablets consumed (r = 0.28, P = 0.04) and to the ratio of tablets consumed to prescribed (r = 0.30, P = 0.03). Patients who were prescribed more than 30 tablets consumed on average 7.8 more tablets than patients prescribed fewer (P = 0.003). Patients who underwent regional anesthesia consumed tablets for longer compared with those who did not (median, 10 versus 4 days; P = 0.03). After undergoing hip arthroscopy, adolescents and young adult patients are commonly overprescribed opioids, consuming on average only one-fifth of the tablets prescribed.

Tibial Tubercle Apophyseal Stage to Determine Skeletal Age in Pediatric Patients Undergoing ACL Reconstruction: A Validation and Reliability Study

Background:

Anterior cruciate ligament (ACL) injuries demand individualized treatments based on an accurate estimation of the child’s skeletal age. Wrist radiographs, which have traditionally been used to determine skeletal age, have a number of limitations, including cost, radiation exposure, and inconvenience.

Purpose:

To evaluate the reliability and validity of a radiographic staging system using tibial apophyseal landmarks as hypothetical proxies for skeletal age to use in the preoperative management of pediatric ACL tears.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

The study included children younger than 16 years of age who underwent ACL reconstruction between July 2008 and July 2018 and received both skeletal age radiography and knee radiography within 3 months of each other. Skeletal age was calculated from hand and wrist radiographs using the Greulich and Pyle atlas. Tibial apophyseal staging was categorized into 4 stages: cartilaginous stage (stage 1), apophyseal stage (stage 2), epiphyseal stage (stage 3), and bony/fused stage (stage 4). Data were collected by 2 independent assessors. The analysis was repeated 1 month later with the same assessors. We calculated descriptive statistics, measures of agreement, and the correlation between skeletal age and apophyseal stage.

Results:

The mean chronological age of the 287 patients included in the analysis was 12.9 ± 1.9 years; 164 (57%) of the patients were male. The overall Spearman r between skeletal age and tibial apophyseal staging was 0.69 (0.77 in males; 0.60 in females). The interrater reliability for the tibial apophyseal staging was substantial (Cohen κ = 0.66), and the intrarater reliability was excellent (Cohen κ = 0.82). The interrater reliability for skeletal age was excellent (intraclass correlation coefficient [ICC] = 0.93), as was the intrarater reliability (ICC = 0.97).

Conclusion:

The observed correlation between skeletal age and tibial apophyseal staging as well as observed intra- and interrater reliabilities demonstrated that tibial apophyseal landmarks on knee radiographs may be used to estimate skeletal age. This study supports the validity of knee radiographs in determining skeletal age and provides early evidence in certain clinical presentations to simplify the diagnostic workup and operative management of pediatric knee injuries, including ACL tears.

Symptomatic Discoid Meniscus in Children and Adolescents: A Review of 470 Cases

BACKGROUND

Discoid meniscus is a congenital variant, typically involving the lateral meniscus, that comprises a spectrum of meniscal shapes and degrees of instability in an estimated 1% to 15% of the population. The purpose of this study was to describe the clinical and operative course of a large cohort of children and adolescents patients with symptomatic lateral discoid meniscus.

METHODS

Medical records of 470 knees with symptomatic lateral discoid meniscus in 401 patients ages 18 years or younger diagnosed at a single institution between 1991 and 2016 were reviewed retrospectively for patient characteristics, treatment course (nonoperative and/or operative), and complications. Surgical reports were reviewed in the operative group.

RESULTS

The series included 401 patients of mean age 11.6 years (range: 1 mo-18.9 y), of which 222 (55%) were female, and 69 (17%) had bilateral involvement. Of 470 knees, 83 (18%) were initially managed nonoperatively. Of these, 32 knees (39%) failed nonoperative management and were converted to surgical treatment at a median of 7.9 months (interquartile range: 4.0-15.1). In total, 419 knees were managed surgically with saucerization (partial meniscectomy) with or without meniscal repair/stabilization; 84 knees (20%) required at least one concurrent nonmeniscal procedure. Discoid meniscus tears were reported in 264/419 knees (63%) intraoperatively; horizontal cleavage tears were most common. Reoperation was required for 66/379 cases (17%) with clinical follow-up, at a median of 19.6 months (range: 9.2-34.9) after index saucerization; 60/379 cases (16%) had ongoing pain and/or mechanical symptoms at final follow-up.

CONCLUSION

With a failure rate of 39% (32/83 knees), nonoperative management for discoid lateral meniscus frequently convert to surgical treatment. During surgery, meniscus tearing and instability are common and should be anticipated. Postoperatively, 33% (126/379) of knees with clinical follow-up underwent either reoperation, or had ongoing symptoms of the knee at final follow-up. Discoid mensical retear is the most common complication (94%, 62/66) prompting repeat surgery, and should be discussed with families before the index operation.

LEVEL OF EVIDENCE

Level IV-descriptive case series.

Novel Magnetic Resonance Imaging Classification of Osteochondritis Dissecans of the Knee: A Reliability Study

BACKGROUND

Current advanced imaging classification systems for osteochondritis dissecans (OCD) of the knee grade severity of disease by identifying certain lesion characteristics. The most widely used are the Hefti and Nelson systems. A novel classification presents a simpler 3-group approach to diagnose knee OCD by magnetic resonance imaging (MRI), compared with the Hefti (5-group) and Nelson (4-group) classifications. The purpose of this study was to compare the reliability of this novel classification with that of the more complex, established systems-an initial step in establishing validity and clinical utility.

METHODS

In total, 120 standardized knee MRIs of patients with established knee OCD were preselected to capture the spectrum of lesion types, with regard to both progression and location of the lesion. Each of the MRIs were independently classified by 2 readers into the novel, Hefti, and Nelson classification systems. A random sample was rereviewed by 1 rater 6 weeks after initial review. The inter-rater and intrarater agreements were evaluated by estimating Krippendorff α.

RESULTS

In total, 106 knees were classified by the novel, Hefti, and Nelson classification systems, as 14 of the knees lacked the necessary MRI sequences. There were no differences in inter-rater and intrarater agreement across classification systems. Krippendorff α for inter-rater agreement was 0.51 (95% confidence interval, 0.33-0.66) for the Hefti classification, 0.50 (0.34-0.64) for the Nelson classification, and 0.49 (0.32-0.65) for the novel classification. The intrarater agreement was 0.88 (0.75-0.97) for the Hefti classification, 0.94 (0.86-0.99) for the Nelson classification, and 0.98 (0.94-1.00) for the novel classification system.

CONCLUSIONS

The novel classification for knee OCD demonstrated near-perfect intrarater agreement and moderate inter-rater agreement, consistent with the current, well-established classification systems. Pending a subsequent study on validity and clinical utility, this simpler classification system may offer an alternative, noninvasive diagnostic method to guide clinical treatment.

LEVEL OF EVIDENCE

Level IV.

Increased incidence of acute patellar dislocations and patellar instability surgical procedures across the United States in paediatric and adolescent patients

PURPOSE

Patellofemoral instability is a common cause of knee pain and dysfunction in paediatric and adolescent patients. The purpose of the study was to evaluate the frequency of patellar dislocations seen in emergency departments (EDs) and the rates of surgical procedures for patellar instability at paediatric hospitals in the United States between 2004 and 2014.

METHODS

The Pediatric Health Information System database was queried for all paediatric patients who underwent surgery for patellar instability or were seen in the ED for acute patellar dislocation between 2004 and 2014. This was compared with the annual numbers of overall orthopaedic surgical procedures.

RESULTS

Between 2004 and 2014, there were 3481 patellar instability procedures and 447 285 overall orthopaedic surgical procedures performed at the included institutions, suggesting a rate of 7.8 per 1000 orthopaedic surgeries. An additional 5244 patellar dislocations treated in EDs were identified. Between 2004 and 2014, the number of patellar instability procedures increased 2.1-fold (95% confidence interval (CI) 1.4 to 3.0), while orthopaedic surgical procedures increased 1.7-fold (95% CI 1.3 to 2.0), suggesting a 1.2-fold relative increase in patellar instability procedures, compared with total paediatric orthopaedic surgeries.

CONCLUSION

This study shows a significant rise in the rate of acute patellar instability treatment events in paediatric and adolescent patients across the country. Surgery for patellar instability also increased over the study period, though only slightly more than the rate of all paediatric orthopaedic surgical procedures. This may suggest that increasing youth sports participation may be leading to a spectrum of increasing injuries and associated surgeries in children.

LEVEL OF EVIDENCE

IV.

Narrow Notch Width is a Risk Factor for Anterior Cruciate Ligament Injury in the Pediatric Population: A Multicenter Study

Purpose

The purposes of this study were to evaluate the notch width index (NWI) as a risk factor for anterior cruciate ligament (ACL) rupture in the pediatric and adolescent patient population via multicenter analysis and to detect any differences in the NWI among cohorts having sustained either a unilateral or bilateral ACL rupture.

Methods

A consecutive series of patients ≤19 years old was enrolled from January 1999 through July 2010 at 2 academic pediatric orthopaedic tertiary-care hospitals. Demographic and anatomic morphology data were collected for 3 cohorts: unilateral ACL ruptures, bilateral ACL ruptures, and a control group. A single blinded reviewer determined notch width measurements via T2 coronal magnetic resonance imaging sequences in a standardized manner, using a previously described technique.

Results

Of the 68 patients included for analysis, 22 sustained unilateral ACL rupture, 23 sustained bilateral ruptures, and 23 comprised the control group. There was a statistically significant difference appreciated in direct comparison of the NWI in the bilateral rupture group and the control group, as well as between the unilateral rupture group and the control group. There was no statistically significant difference between the NWI in the unilateral versus the bilateral rupture group.

Conclusion

Given the known inconsistencies in the existing literature, our findings provide further support of a narrow NWI as a significant contributing factor to both unilateral and bilateral ACL injury risk in the pediatric and adolescent patient population.

Level of Evidence

III, retrospective cohort study.

Early Outcomes of Adolescent ACL Reconstruction With Hybrid Hamstring Tendon Autograft-Allograft Versus Hamstring Tendon Autograft Alone

Background:

Small-diameter semitendinosus-gracilis tendon autografts may be encountered intraoperatively during anterior cruciate ligament reconstruction (ACLR); these have been shown to be at increased risk of graft rupture. One option that surgeons have pursued to reduce the theoretical failure rate of these smaller-diameter grafts is augmenting them with allograft material, thereby forming a larger-diameter hybrid autograft-allograft construct.

Purpose/Hypothesis:

The purpose of this study was to compare outcomes in adolescent athletes of primary ACLR using a hybrid autologous hamstring tendon and soft tissue allograft construct versus ACLR using small-diameter hamstring tendon autograft. The hypothesis was that the hybrid hamstring autograft-allograft construct would provide superior short-term results.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We performed a retrospective analysis of 47 patients aged between 12 and 20 years who underwent hybrid graft ACLR (mean diameter, 9.1 mm) at a single institution. Electronic medical records including clinic notes, radiographic images, operative notes, and pathology reports were reviewed for study analysis. A control group of 64 patients who underwent small-diameter hamstring reconstruction (mean diameter, 7.1 mm) without allograft supplementation was compiled. Corresponding clinical, radiographic, and surgical characteristics were collected for the control group to allow for comparative analysis.

Results:

Mean follow-up was 2.7 years for the hybrid cohort and 2.3 years for the control group. Despite a significantly larger mean graft diameter in the hybrid group as compared with the control group (P < .001), no significant difference in retear rate was seen between cohorts (hybrid, 9%; control, 13%; P = .554). Patients with hybrid anterior cruciate ligament constructs also underwent a comparable number of reoperations overall (P = .838). Functionally, all patients with adequate follow-up returned to sports, with no significant difference in time to return to sports between the groups (P = .213). Radiographically, hybrid graft constructs did not undergo a significantly larger degree of tunnel lysis (P = .126).

Conclusion:

A cohort of adolescents with hybrid anterior cruciate ligament grafts was shown to have retear rates and overall clinical results comparable with those of a control group that received small-diameter hamstring tendon autografts alone.

Operative Treatment of Bipartite Patella in Pediatric and Adolescent Athletes: A Retrospective Comparison With a Nonoperatively Treated Cohort

Background:

Bipartite patella (BPP) is a developmental anomaly that forms when incomplete patellar ossification leaves a residual fibrocartilaginous synchondrosis between ossification centers. Repetitive traction forces across the synchondrosis can cause knee pain, most commonly presenting in adolescence. Symptoms frequently resolve with nonoperative management. Few surgical case series exist to guide treatment approaches for refractory pain.

Purpose:

To investigate the clinical features, surgical techniques, and outcomes associated with operative treatment of symptomatic BPP in pediatric and adolescent athletes and to compare features of the series with a large control group managed nonoperatively.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective medical record review was conducted of all patients aged ≤20 years who were diagnosed with symptomatic, radiologically confirmed BPP between 2003 and 2018 at a single tertiary-care pediatric hospital (N = 266). Demographic and clinical variables were analyzed, and additional radiologic and perioperative variables were collected for the surgical subcohort.

Results:

Of the 266 patients included, 27 were treated operatively (10.2%). When compared with those treated nonoperatively (with rest, physical therapy, cryotherapy, and anti-inflammatory medications), the operatively managed group experienced a longer duration of symptoms before first presentation (21.5 vs 7.6 months; P < .001) and were more likely to be older (mean age, 15.4 vs 12.4 years; P < .001), female (59.3% vs 35.6%; P = .03), and competitive athletes (100% vs 84.5%; P = .02). In the 27 patients treated operatively, procedures were categorized as isolated fragment excision (n = 9), fragment excision with lateral release (n = 8), isolated lateral release (n = 5), fragment screw fixation (n = 4), and synchondrosis drilling (n = 1). The mean time between surgery and return to sports was 2.2 months. Four patients (14.8%) reported residual symptoms requiring secondary surgery, including lateral release (n = 1), excision of residual fragment (n = 1), and fixation screw removal (n = 2).

Conclusion:

BPP can cause knee pain in adolescent athletes and is generally responsive to nonoperative treatment. Patients undergoing surgical treatment—most commonly female competitive athletes with prolonged symptoms—represented 10% of cases. A variety of surgical techniques may be effective, with a 15% risk of persistent or recurrent symptoms warranting reoperation. Prospective multicenter investigations are needed to identify optimal candidates for earlier interventions and the optimal operative treatment technique.

Tibial tubercle fractures in children and adolescents: a large retrospective case series

To report patient characteristics, fracture types, treatment methods, early clinical outcomes and complications of children and adolescents treated for tibial tubercle fractures. Retrospective case series of patients 18 years old and younger treated for tibial tubercle fractures at a single institution from 1995 to 2015. Clinical and radiographic outcomes were reported at minimum six-month follow-up. In 228 patients, 236 tibial tubercle fractures were identified, of whom, 198 (87%) were males. Mean age and BMI was 14.3 years and 25.0, respectively. Pre-existing Osgood-Schlatter disease was identified in 31% cases and was most commonly associated with type I fractures (P < 0.001). Most fractures occurred while participating in athletics (86%). Initial treatment was surgical for 67% fractures. Type III fractures were most common (41%), followed by type I (29%). Type I fractures were most commonly treated nonoperatively (91%) and types II-V fractures were most commonly treated surgically (89%, P < 0.001). Compartment syndrome was identified in 4 (2%) patients, 3 of which had type IV fractures. Most patients returned to sports (88%). Tibial tubercle fractures are sports-related injuries and occur most commonly in adolescent males. They can be associated with pre-existing Osgood-Schlatter disease, a higher than average BMI, and a small but relevant risk of compartment syndrome. Following treatment, most patients return to sports participation.

Complications and Controversies in the Management of 5 Common Pediatric Sports Injuries

Growing participation in sports among children, along with increasingly intense training regimens, has contributed to an increasing rate of sports-related injuries. Despite the similarities to adult sports injuries, pediatric patients have distinctive injury patterns because of the growing physis and therefore necessitate unique treatment algorithms. Caring for these injured children requires in-depth knowledge of not only pediatric injury patterns, but also the scope of age-specific treatments, the associated complications, and the controversies. When treating motivated pediatric athletes, one must be able to strike a delicate balance between patients' eagerness to return to sport and the need to ensure their long-term health and function. Knowledge of controversies and complications will help both patients and physicians make informed decisions about how best to restore pediatric athletes back to health.

Osteochondritis Dissecans of the Tibial Plateau in Children and Adolescents: A Case Series

Background:

Osteochondritis dissecans (OCD) of the knee is a relatively well-known condition, most commonly arising in the femoral condyle. Lesions arising in the tibial plateau are rarely described.

Purpose:

To present a case series of OCD lesions of the tibial plateau.

Study Design:

Case series; Level of evidence, 4.

Methods:

Medical records and diagnostic imaging of patients <20 years of age with confirmed diagnosis of OCD of the tibial plateau from a single institution were retrospectively reviewed. Characteristic and radiographic features as well as details of both nonoperative and surgical management were investigated. Lesion characteristics and treatment outcomes were also analyzed.

Results:

A total of 9 lesions were identified in 9 patients (5 females, 4 males) who fit the inclusion criteria. The mean age at diagnosis was 14.2 years (range, 9-17 years). Knee pain (8/9) of longer than 1 year in duration was the most common presenting symptom. All 9 lesions were located on the lateral tibial plateau, and concomitant lateral compartment pathology was present in 5 of 9 patients (4 lateral femoral condyle OCDs, 3 lateral meniscal tears [1 discoid], and 1 discoid meniscus). Only 2 lesions were visible on initial radiographs; all 9 were visible on magnetic resonance imaging. All patients underwent initial nonoperative treatment; 2 patients demonstrated resolution of symptoms. Two patients underwent surgery for concomitant pathology, and the OCD was not addressed surgically. A total of 5 patients continued to be symptomatic after nonoperative treatment, prompting surgical intervention, which consisted of microfracture and chondroplasty in all 5 cases. A total of 2 of the 5 microfracture patients had resolution of symptoms, while another 2 patients had continued symptoms ultimately responsive to steroid injection treatment. One patient had revision microfracture, followed by autologous chondrocyte implantation and an arthroscopic lysis of adhesions. At final follow-up, ranging from 7 months to 10 years, 8 patients were asymptomatic, while 1 patient had developed early osteoarthritis.

Conclusion:

OCD of the tibial plateau in young patients is rare, usually involves the lateral side, and may have significant long-term implications for knee function. Presenting symptoms are often vague, and lesions may not always be visible on initial radiographs, which may lead to delayed treatment and adversely affect outcomes.

Osteochondritis Dissecans of the Knee: An Interrater Reliability Study of Magnetic Resonance Imaging Characteristics

BACKGROUND

Imaging characteristics of osteochondritis dissecans (OCD) lesions quantified by magnetic resonance imaging (MRI) are often used to inform treatment and prognosis. However, the interrater reliability of clinician-driven MRI-based assessment of OCD lesions is not well documented.

PURPOSE

To determine the interrater reliability of several historical and novel MRI-derived characteristics of OCD of the knee in children.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A total of 42 OCD lesions were evaluated by 10 fellowship-trained orthopaedic surgeons using 31 different MRI characteristics, characterizing lesion size and location, condylar size, cartilage status, the interface between parent and progeny bone, and features of both the parent and the progeny bone. Interrater reliability was determined via intraclass correlation coefficients (ICCs) with 2-way random modeling, Fleiss kappa, or Krippendorff alpha as appropriate for each variable.

RESULTS

Raters were reliable when the lesion was measured in the coronal plane (ICC, 0.77). Almost perfect agreement was achieved for condylar size (ICC, 0.93), substantial agreement for physeal patency (ICC, 0.79), and moderate agreement for joint effusion (ICC, 0.56) and cartilage status (ICC, 0.50). Overall, raters showed significant variability regarding interface characteristics (ICC, 0.25), progeny (ICC range, 0.03 to 0.62), and parent bone measurements and qualities (ICC range, -0.02 to 0.65), with reliability being moderate at best for these measurements.

CONCLUSION

This multicenter study determined the interrater reliability of MRI characteristics of OCD lesions in children. Although several measurements provided acceptable reliability, many MRI features of OCD that inform treatment decisions were unreliable. Further work will be needed to refine the unreliable characteristics and to assess the ability of those reliable characteristics to predict clinical lesion instability and prognosis.

Long-Term Follow-up of Skeletally Immature Patients With Physeal-Sparing Combined Extra-/Intra-articular Iliotibial Band Anterior Cruciate Ligament Reconstruction: A 3-Dimensional Motion Analysis

BACKGROUND

The physeal-sparing iliotibial band (ITB) anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-established technique for treating skeletally immature patients with ACL rupture. However, the long-term implications of the procedure on the intricacies of kinetic and kinematic function of the knee have not been comprehensively investigated.

PURPOSE

To assess the short-, mid-, and long-term effects of ITB ACLR on kinetic and kinematic parameters of knee functions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 38 patients who had undergone an ITB ACLR as a skeletally immature child were recruited to participate in a 3-dimensional (3D) motion analysis testing protocol at an institutional injury prevention center between 1 and 20 years after reconstruction. Exclusion criteria were congenital ACL deficiency and any other major knee injury (defined as an injury requiring surgery or rehabilitation >3 months) on either knee. 3D and force plate parameters included in the analysis were knee moment, ground-reaction force, and vertical jump height measured during drop vertical jump and vertical single-limb hop. Paired t tests and equivalency analyses were used to compare the parameters between cases (ITB ACLR limb) and controls (contralateral/nonsurgical limbs).

RESULTS

Paired t tests showed no statistically significant differences between limbs, and equivalency analyses confirmed equivalency between limbs for all tested outcome variables.

CONCLUSION

The ITB ACLR appears to restore normal, symmetric, physiologic kinetic and kinematic function in the growing knee by 1 year after reconstruction, with maintenance of normal parameters for up to 20 years.

Descriptive Epidemiology of Adolescent Clavicle Fractures: Results From the FACTS (Function after Adolescent Clavicle Trauma and Surgery) Prospective, Multicenter Cohort Study

Background:

The majority of previous investigations on operative fixation of clavicle fractures have been related to the adult population, with occasional assessments of the younger, more commonly affected adolescent population. Despite limited prospective data for adolescents, the incidence of operative fixation of adolescent diaphyseal clavicle fractures has increased.

Purpose:

To detail the demographic features and descriptive epidemiology of a large pooled cohort of adolescent patients with diaphyseal clavicle fractures presenting to pediatric tertiary care centers in the United States through an observational, prospective, multicenter cohort study (Function after Adolescent Clavicle Trauma and Surgery [FACTS]).

Study Design:

Cross-sectional study; Level of evidence, 4.

Methods:

Patients aged 10 to 18 years who were treated for a diaphyseal clavicle fracture between August 2013 and February 2016 at 1 of 8 geographically diverse, high-volume, tertiary care pediatric centers were screened. Treatment was rendered by any of the pediatric orthopaedic providers at each of the 8 institutions, which totaled more than 50 different providers. Age, sex, race, ethnicity, fracture laterality, hand dominance, mechanism of injury, injury activity, athletic participation, fracture characteristics, and treatment decisions were prospectively recorded in those who were eligible and consented to enroll.

Results:

A total of 545 patients were included in the cohort. The mean age of the study population was 14.1 ± 2.1 years, and 79% were male. Fractures occurred on the nondominant side (56%) more frequently than the dominant side (44%). Sport was the predominant activity during which the injury occurred (66%), followed by horseplay (12%) and biking (6%). The primary mechanism of injury was a direct blow/hit to the shoulder (60%). Overall, 54% were completely displaced fractures, defined as fractures with no anatomic cortical contact between fragments. Mean shortening within the completely displaced group was 21.9 mm when measuring the distance between fragment ends (end to end) and 12.4 mm when measuring the distance between the fragment end to the corresponding cortical defect (cortex to corresponding cortex) on the other fragment (ie, true shortening). Comminution was present in 18% of all fractures. While 83% of all clavicle fractures were treated nonoperatively, 32% of completely displaced fractures underwent open reduction and internal fixation.

Conclusion:

Adolescent clavicle fractures occurred more commonly in male patients during sports, secondary to a direct blow to the shoulder, and on the nondominant side. Slightly more than half of these fractures were completely displaced, and approximately one-fifth were comminuted. Within this large cohort, approximately one-third of patients with completely displaced fractures underwent surgery, allowing for future prospective comparative analyses of radiographic, clinical, and functional outcomes.