Childhood Obesity is Associated With Osteochondritis Dissecans of the Knee, Ankle, and Elbow in Children and Adolescents.

BACKGROUND: Osteochondritis dissecans (OCD) is a joint disorder of the subchondral bone and articular cartilage whose association with obesity in children is not clearly known. The purpose of this study was to assess the magnitude of the association between childhood obesity and the occurrence of OCD of the knee, ankle, and elbow in children. METHODS: A retrospective chart review of an integrated health system was performed on OCD patients aged 2 to 19 from 2007 to 2011, with over 1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. The body mass index (BMI) for each patient in the cohort was used to stratify patients into 5 weight classes (underweight, normal weight, overweight, moderately obese, and extremely obese) based on BMI-for-age. The associations between the 5 weight classes and OCD of the ankle, knee, and elbow were assessed using multiple logistic regression models to estimate odds ratios (OR) and 95% confidence intervals using multivariate analysis to adjust for patient demographic variables. RESULTS: In total, 269 patients fit the inclusion criteria. Mean BMI, both absolute and percentile, was significantly higher for patients with OCD of the knee, elbow, and ankle than patients without OCD. In the multivariate analysis, extremely obese patients were found to have an increased OR of OCD for all patients, with an 86% increased risk of any OCD compared with normal weight patients. In addition, assessment by different types of OCD revealed that extremely obese patients had an increased OR of OCD of the elbow and ankle individually, with a 3.1 times increased OCD elbow risk and 3.0 times increased risk of ankle OCD in extremely obese patients. Although extremely obese patients did not have a statistically significant increased risk of knee OCD, moderately obese patients did have a 1.8 times increased risk of knee OCD as compared with normal weight children. There were no significantly different risks of any type of OCD seen in overweight or underweight patients as compared with normal weight patients. CONCLUSIONS: In this population-based cohort study, extreme obesity is strongly associated with an increased risk of OCD overall and OCD of the elbow and ankle specifically. In addition, moderate obesity is associated with an increased risk of knee OCD. All types of OCD were also found to have a significantly greater average BMI when compared with patients without OCD. LEVEL OF EVIDENCE: Level IV-descriptive epidemiology study.

Incidence of Osteochondritis Dissecans in Adults.

BACKGROUND: Osteochondritis dissecans (OCD) has frequently been described in children and adolescents, but cases of OCD in adults are certainly encountered. Little has been published on the epidemiology of OCD in adult patients. PURPOSE: To assess the frequency of OCD lesions in adults and assess the risk by age, sex, and ethnicity. STUDY DESIGN: Descriptive epidemiology study. METHODS: The authors assessed all patients aged 20 to 45 years from the entire database of patients enrolled as members of Kaiser Permanente Southern California from January 2011 until December 2013. Kaiser Southern California is an integrated health care system serving a racially, ethnically, and socioeconomically diverse population of >3.5 million patients. A retrospective chart review was done on OCD during this period. Inclusion criteria included OCD of any joint. Exclusion criteria included traumatic osteochondral fractures and coexistence of intra-articular lesions other than OCD. Joint involvement/location, laterality, and all patient demographics were recorded. RESULTS: Among 122 patients, a total of 124 OCD lesions were found. The majority of lesions were in the ankle (n = 76) and knee (n = 43), with 3 foot lesions and 2 elbow lesions identified. OCD lesions were identified in 75 men (62%) and 47 women (38%). Overall incidence rates per 100,000 person-years were 3.42 for all OCD, 2.08 for ankle OCD, and 1.21 for knee OCD. The relative risk of adult OCD for men was twice that of women. The relative risk of adult OCD for white patients was 2.3 that of Asians and 1.7 that of Hispanics. Risk of knee OCD was 3.6 times higher for men than women. As compared with women, men had a higher risk for lateral femoral condyle OCD lesions versus the medial femoral condyle ( P = .05; odds ratio [OR], 5.19). CONCLUSION: This large cohort study of Southern California adults with OCD demonstrated an increased OR for men (vs women) of OCD in all joints. The majority of symptomatic lesions were present in the ankle rather than the knee, as previously found in children. White and black patients had the highest OR of OCD; men had a significantly greater OR of lateral femoral condyle knee lesions as compared with women.

Demographics and Epidemiology of Osteochondritis Dissecans of the Elbow Among Children and Adolescents.

BACKGROUND: Osteochondritis dissecans (OCD) of the elbow is a disorder of subchondral bone and articular cartilage, of which the incidence among children is not clearly known. PURPOSE: To assess the demographics and epidemiology of OCD of the elbow among children. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A retrospective chart review of an integrated health system for the years 2007 through 2011 was performed for patients with elbow OCD aged 2 to 19 years. Lesion location, laterality, and all patient demographics were recorded. OCD incidence was determined for the group as a whole as well as by sex and age group (2-5, 6-11, 12-19 years). Patient differences based on age, sex, and ethnicity were analyzed, and multivariable logistic regression models were used to assess the risk of elbow OCD by group. RESULTS: A total of 37 patients with 40 OCD lesions fit the inclusion criteria. No lesion was found among 2- to 5-year-olds. A majority of lesions (n = 39, 97.5%) were in the capitellum, and 1 (2.5%) was in the trochlea. Twenty-five patients (67.6%) had right-sided lesions; 9 (24.3%), left-sided; and 3 (8.1%), bilateral. The incidence of elbow OCD for patients aged 6 to 19 years was 2.2 per 100,000 overall and 3.8 and 0.6 per 100,000 for males and females, respectively. The majority of OCD cases were seen in those aged 12 to 19 years, with an incidence of 3.4 per 100,000 versus 0.38 among 6- to 11-year-olds. Multivariable logistic regression analysis revealed a 21.7-times increased odds ratio of elbow OCD among patients aged 12 to 19 years versus 6 to 11 years, and males had a 6.8-times greater odds ratio of elbow OCD than females (P < .0001 for both). Based on race and ethnicity, non-Hispanic whites had the highest incidence of elbow OCD as compared with all other ethnic groups. CONCLUSION: In this population-based cohort study of pediatric elbow OCD, males had almost 7 times the risk of elbow OCD as compared with females, and 12- to 19-year-olds had nearly 22 times the risk of elbow OCD versus 6- to 11-year-olds. In keeping with many prior studies, the majority of patients had right-sided lesions.

Ankle Injury Prevention Programs for Soccer Athletes Are Protective: A Level-I Meta-Analysis.

BACKGROUND: Soccer has one of the highest rates of ankle injury in sports for both males and females. Several injury prevention programs have been developed to address this concern. The purposes of this study were to conduct a meta-analysis of ankle injury prevention programs for soccer players, assess the heterogeneity among the studies, and evaluate the reported effectiveness of the prevention programs. METHODS: A systematic search of the literature was conducted in PubMed (MEDLINE), Embase, CINAHL (Cumulative Index to Nursing and Allied Health), and the Cochrane Central Register of Controlled Trials (CENTRAL) database. Studies were limited to clinical investigations of injury prevention programs specific to the ankle in soccer players. Title, abstract, and full-text review were utilized to identify articles that met the inclusion criteria. The Cochrane Q test and I(2) index were independently used to assess heterogeneity among the studies. Sensitivity analyses were performed to assess heterogeneity. The pooled risk difference was calculated by random-effects models with use of the DerSimonian-Laird method. Publication bias was assessed with a funnel plot and Egger weighted regression technique. RESULTS: Ten studies met the inclusion criteria as randomized controlled trials. A total of 4,121 female and male soccer athletes were analyzed for ankle injuries. Significant heterogeneity was found among studies of ankle injury prevention (p = 0.002), with an I(2) index of 65.2%. For studies of ankle injury prevention programs, the risk ratio was 0.60 (95% confidence interval, 0.40 to 0.92) and a significant reduction in the risk of ankle injury was found in the prevention group (p = 0.002). No evidence of publication bias was found among the included studies. CONCLUSIONS: This meta-analysis of studies regarding ankle injury prevention programs identified a significant reduction in the risk of ankle injury. Future high-quality research designs with a low risk of bias are necessary to further evaluate the effectiveness of specific exercises and the optimal timing and age at intervention for the prevention of ankle injuries in the athletic soccer player. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The Relationship of the Femoral Physis and the Medial Patellofemoral Ligament in Children: A Cadaveric Study.

BACKGROUND: Young athletes sustain patellar dislocations in a variety of sports. The medial patellofemoral ligament (MPFL) is a critical structure that functions as an anatomic checkrein to help prevent lateral patellar dislocation. Reconstruction of this ligament is challenging in patients with open physes because of concerns about iatrogenic damage to the femoral physis. PURPOSE: To evaluate the relationship of the distal femoral physis and the MPFL. STUDY DESIGN: Descriptive laboratory study. METHODS: In 15 cadaveric, pediatric knees (age, 7-11 years), markers were placed at the proximal/distal limits of the MPFL femoral attachment and were evaluated with computed tomography. The distance from the MPFL attachment midpoint to the most medial aspect of the distal femoral physis was measured. RESULTS: The mean femoral width of the MPFL was 8.1 mm (range, 4.3-13.8 mm). The femoral MPFL midpoint was distal to the femoral physis in 11 specimens and proximal to the physis in 4 specimens. The most proximal portion of the MPFL femoral attachment extended above the medial physis in 7, was at the physis in 5, and was below the physis in 3 specimens. One specimen had the entire MPFL femoral attachment above the physis. For knees with the MPFL midpoint above the medial physis, the distance between the center of the MPFL and physis was 3.3 mm (range, 0.3-7.1 mm). For knees with the MPFL below the medial physis, the distance between the center of the MPFL and physis was -6.8 mm (range, -0.7 to -22.0 mm). CONCLUSION: The relationship of the femoral attachment of the MPFL and the medial femoral physis shows some anatomic variation. In all cases, the MPFL is close to the medial femoral physis, but the midpoint of the MPFL is at, slightly above, or slightly below the physis. CLINICAL RELEVANCE: The relationship of the MPFL femoral attachment footprint to the femoral physis in the skeletally immature patient is not well understood, and access to pediatric cadaveric tissue is very limited. This small series demonstrates that there is considerable variation in the relationship between the MPFL and distal femoral physis. This anatomic information may guide MPFL reconstruction technique in young patients and reduce the risk of iatrogenic physeal arrest on the femur.

The Anterolateral Ligament of the Knee: An Inconsistent Finding in Pediatric Cadaveric Specimens.

BACKGROUND: The anterolateral ligament (ALL) of the knee has been identified as a structure that limits internal rotation, and thus, affects the pivot shift mechanism. It has previously been reported in a high percentage of adult subjects. The purpose of the current study was to evaluate whether the ALL could be identified on pediatric cadaveric knee specimens and compare these findings to previously published reports. METHODS: Eight skeletally immature cadaver knee specimens were examined through gross dissection: ages 3 months, 4 months, 1 year, 2 years, 3 years, 3 years, 8 years, and 10 years. There were 3 male and 5 female (7 right, 1 left) specimens. The presence or absence of the ALL was documented in each specimen, through dissection, intermittent internal and external rotation of the tibia, and anterior translation of the tibia, to produce tension of the lateral collateral tissues and joint capsule. These dissections were performed by a group of fellowship-trained orthopaedic surgeons. RESULTS: The iliotibial band, entire lateral joint capsule, lateral collateral ligament, and popliteus were readily identified in each specimen. In 7 specimens, a distinct ALL structure was not identified during dissection. The ALL was identified in 1 of 8 specimens (1-year-old female, right knee). The ALL was further delineated under applied internal rotational stress. CONCLUSIONS: Previous research has suggested that this ligament is present in the majority of adult specimens. This finding was not reproduced in the current study of pediatric cadaveric specimens, where only one of 8 specimens had an identifiable ALL. This suggests that this ligament may develop later in life, after physiological loads are applied to the joint capsule. Further research in both adult and pediatric knees needs to be conducted to further elucidate the development of this ligament, and the role of this structure in knee stability. CLINICAL RELEVANCE: The ALL is a knee ligament that has been described in adults. However, it is unclear whether this structure is present or fully developed in younger populations. The current study sought to identify the ALL in pediatric cadaver knee specimens, identifying this structure in only one of 8 specimens. The findings of this study suggest that the ALL may be an inconsistent structure in the pediatric population.

The Incidence of Surgery in Osteochondritis Dissecans in Children and Adolescents.

BACKGROUND: The frequency of osteochondritis dissecans (OCD), a disorder of the subchondral bone and articular cartilage, is not well described. PURPOSE: To assess the frequency of pediatric OCD lesions that progress to surgery based on sex, joint involvement, and age. STUDY DESIGN: Descriptive epidemiology study. METHODS: A retrospective chart review (2007-2011) was performed on OCD. Inclusion criteria included OCD of any joint and patients aged 2 to 19 years. Exclusion criteria included traumatic osteochondral fractures or coexistence of non-OCD intra-articular lesions. Differences in progression toward surgery were compared between age groups, sex, and joint location. Logistical regression analysis was performed by sex, age, and ethnicity. RESULTS: Overall, 317 patients with a total of 334 OCD lesions were found. The majority of lesions (61.7%) were in the knee, with ankle, elbow, shoulder, and foot lesions representing 25.4%, 12.0%, 0.6%, and 0.3% of all lesions, respectively. The majority of joints needing surgery were in the knee (58.5%), with ankle and elbow lesions representing 22.9% and 18.6% of surgeries performed, respectively. The percentage of all OCD lesions progressing to surgery was 35.3%; surgical progression for knee, ankle, and elbow joints was 33.5%, 31.8%, and 55.0%, respectively. Logistic regression analysis found no statistically significant different risk of progressing to surgery for OCD of the knee, elbow, and ankle between sexes. Patients aged 12 to 19 years had a 7.4-times greater risk of progression to surgery for knee OCD lesions than 6- to 11-year-olds. Patients aged 12 to 19 years were 8.2 times more likely to progress to surgery for all OCD lesions than patients aged 6 to 11 years. Progression to surgery of ankle OCD did not significantly differ based on location. Three of 4 trochlear lesions progressed to surgery, along with 1 of 1 tibial, 1 of 3 patellar, 40.3% of lateral femoral condylar, and 28.2% of medial femoral condylar lesions. CONCLUSION: In this large cohort study of pediatric OCD patients, 35% progressed to surgery. Progression to surgery did not differ significantly between sexes with OCD of any joint. Progression to surgery for OCD of the knee, elbow, and ankle strongly correlated with patient age at the time of diagnosis. CLINICAL RELEVANCE: The knowledge of likelihood of progression to surgery of OCD by location, sex, and age is useful in counseling patients and in planning treatment. This study confirms a worse prognosis in the nonoperative treatment of older patients with OCD.

Review of anterior cruciate ligament reconstruction cost variance within a regional health care system.

BACKGROUND: Examination of value in health care has become a national priority in the United States. Regional variation in health care costs is an area of focus among national policy experts. Procedural cost data can be used to provide physicians with information to evaluate costs and value. PURPOSE: To perform a cost review for anterior cruciate ligament (ACL) surgery to document the degree of variation in costs for ACL reconstruction. STUDY DESIGN: Economic and decision analysis; Level of evidence, 4. METHODS: A procedural cost review was performed for isolated ACL reconstructions within a 22-surgeon, 7-hospital system. Five consistent cost categories under the influence of the surgeon were identified and were analyzed for cost variation among surgeons: tibial fixation, femoral fixation, graft choice, sutures, and tools or disposable instruments. RESULTS: For these 5 categories, the total costs to perform an ACL reconstruction (in 2013 US dollars) ranged from $392.80 to $4670.31, a difference of $4277.51 and a mean of $2039.09. Tibial fixation costs ranged from $95.00 to $760.00 (mean, $293.52). Femoral fixation ranged from $95.00 to $865.00 (mean, $367.14). The graft cost ranged from $1275.00 to $2545.75 (mean, $1976.43). Suture prices for each individual suture varied from $1.19 to $46.00 (mean, $18.26). Tools and disposable supplies ranged from $40.10 to $2136.00 (mean, $452.33). CONCLUSION: There were substantial differences in ACL reconstruction costs in the implant and disposable instruments categories. As health systems and physicians collaborate to improve health care quality and value for patients, information on cost variation will be important. Rational variation in health care cost is appropriate, reflecting variation due to the unique requirements of procedures and patient-centered care. Irrational variations in procedural costs are those that do not add additional value.

Volumetric Damage to the Femoral Physis During Double-Bundle Posterior Cruciate Ligament Reconstruction: A Magnetic Resonance Imaging Computer Modeling Study.

PURPOSE: The purpose of this study was to use computer models to evaluate the volume of femoral physeal disruption in double-bundle posterior cruciate ligament (PCL) reconstruction in patients with open physes. METHODS: Ten skeletally immature patients (6 girls and 4 boys) were selected for this study. The magnetic resonance imaging scans of each patient were converted into a 3-dimensional model using computer-aided design/computer-aided manufacturing software. The software allowed the users to differentiate the epiphyseal, physeal, and metaphyseal tissues. This allowed for quantification of volume removed of each tissue type. Furthermore, we used the 3-dimensional models to simulate an anatomic double-bundle technique using 6-, 7-, 8-, and 9-mm-diameter tunnels. The software method reflects an inside-out drilling technique. RESULTS: For drill holes of all diameters, the posteromedial tunnels exited the knee inferior to the physis, thus avoiding physeal damage. In contrast, all the anterolateral tunnels perforated the physis. The results for the percent of total physis removed are as follows: 6-mm tunnel, 1.79% ± 0.99%; 7-mm tunnel, 2.23% ± 1.19%; 8-mm tunnel, 3.00% ± 1.54%; and 9-mm tunnel, 3.84% ± 1.73%. CONCLUSIONS: This computer modeling simulation of double-bundle PCL reconstruction in skeletally immature knees found that the posteromedial tunnel avoided disruption of the distal femoral physis. In contrast, the anterolateral tunnel did disrupt the physis with all drill hole sizes (6 to 9 mm), but all had a less than 4% volume of total physis removed. CLINICAL RELEVANCE: A clear understanding of the drill hole position may reduce the volume of physeal injury during double-bundle PCL reconstruction. This study shows that physeal disruption of less than the experimental 7% threshold that has been shown to cause physeal arrest may not cause arrest, but this is still speculative.

The patellar insertion of the medial patellofemoral ligament in children: a cadaveric study.

BACKGROUND: The purpose of this study was to evaluate the medial patellofemoral ligament (MPFL) patellar insertion in skeletally immature anatomic specimens. METHODS: Nine pediatric cadaveric knee specimens were examined through gross dissection. Metallic markers were placed at the MPFL patellar insertion footprint. Computed tomographic scans for each specimen were analyzed. The MPFL insertion footprint width, patellar height, and patellar width were measured. The distance from the MPFL insertion footprint center to the midline of the patella was assessed. The proportion of the patella that the MPFL footprint inserted upon was calculated. RESULTS: The mean width of the MPFL patellar insertion footprint was 12 mm (range, 8 to 18 mm). The mean patellar height was 31 mm (range, 20 to 48 mm). The mean patellar width was 27 mm (range, 21 to 39 mm). The center of the MPFL insertion footprint was found to be a mean 4.7 mm (range, -2 to 10.5 mm) above the midline of the patella, with insertion centers occurring both above and below the midline. The MPFL insertion footprint spanned a mean 41% (24% to 63%) of the longitudinal width of the patella. CONCLUSIONS: Most adult studies report the MPFL insertion on the upper 1/2 to 2/3 of the patella. This series of skeletally immature subjects demonstrated that the center of the MPFL insertion was above and below the midpoint of the patella. The MPFL insertions of some of the younger specimens did extend into the distal 1/3 of the patella. The insertion of the older specimens was found in the proximal 2/3 of the patella, a similar location to most previous adult anatomic studies. CLINICAL RELEVANCE: This research suggests that the MPFL insertion on the patella may be at slightly different locations in some skeletally immature subjects compared with adults. The specimens dissected in the present study showed more variability than previously published reports, with some insertions extending into the distal 1/3 of the patella in the youngest subjects. These dissections may be useful to surgeons performing MPFL reconstructions in skeletally immature patients.

Novel radiographic feature classification of knee osteochondritis dissecans: a multicenter reliability study.

BACKGROUND: Osteochondritis dissecans (OCD) is a vexing condition for patients, parents, and physicians because of the frequent slow healing and nonhealing that leads to prolonged treatment. Several features on plain radiographs have been identified as predictors of healing, but the reliability of their measurement has not been established. PURPOSE: To determine the inter- and intrarater reliability of several radiographic features used in the diagnosis, treatment, and prognosis of OCD femoral condyle lesions. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: Pretreatment anteroposterior, lateral, and notch radiographs of 45 knees containing OCD lesions of the medial or lateral femoral condyle were reviewed in blinded fashion by 7 orthopaedic physician raters from different institutions over a secure web portal at 2 time points over a month apart. Classification variables included lesion location, growth plate maturity, parent bone radiodensity, progeny bone fragmentation, progeny bone displacement, progeny bone contour, lesion boundary, and radiodensity of the lesion center and rim. Condylar width and lesion size were measured on all views. Interrater reliability was assessed using free-marginal kappa and intraclass correlations. Intrarater reliability was assessed using the Cohen kappa, linear-weighted kappa, and intraclass correlations based on measurement type. RESULTS: Raters had excellent reliability for differentiating medial and lateral lesions and growth plate maturity and for measuring condylar width and lesion size. In the subset of knees with visible bone in the lesion, the fragmentation, displacement, boundary, central radiodensity, and contour (concave/nonconcave) of the lesion bone were classified with moderate to substantial reliability. The radiodensity of the lesion rim and surrounding epiphyseal bone were classified with poor to fair reliability. CONCLUSION: Many diagnostic features of femoral condyle OCD lesions can be reliably classified on plain radiographs, supporting their future testing in multifactorial classification systems and multicenter research to develop prognostic algorithms. Other radiographic features should be excluded, however, because of poor reliability.

Anterior Cruciate Ligament and Knee Injury Prevention Programs for Soccer Players: A Systematic Review and Meta-analysis.

BACKGROUND: Soccer has one of the highest incidences of anterior cruciate ligament (ACL) injuries for both males and females. Several injury prevention programs have been developed to address this concern. However, an analysis of the pooled effect has yet to be elicited. PURPOSE: To conduct a systematic review and meta-analysis of ACL and knee injury prevention programs for soccer players, assess the heterogeneity among the studies, and evaluate the reported effectiveness of the prevention programs. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A systematic search of the literature was conducted on PubMed (Medline), Embase, CINAHL, and Central-Cochrane Database. Studies were limited to randomized controlled trials (RCTs) of injury prevention programs specific to the knee and/or ACL in soccer players. The Cochrane Q test and I (2) index were independently used to assess heterogeneity among the studies. The pooled risk difference, assessing knee and/or ACL injury rates between intervention and control groups, was calculated by random-effects models with use of the DerSimonian-Laird method. Publication bias was assessed with a funnel plot and Egger weighted regression technique. RESULTS: Nine studies met the inclusion criteria as RCTs. A total of 11,562 athletes were included, of whom 7889 were analyzed for ACL-specific injuries. Moderate heterogeneity was found among studies of knee injury prevention (P = .041); however, there was insignificant variation found among studies of ACL injury prevention programs (P = .222). For studies of knee injury prevention programs, the risk ratio was 0.74 (95% CI, 0.55-0.89), and a significant reduction in risk of knee injury was found in the prevention group (P = .039). For studies of ACL injury prevention programs, the risk ratio was 0.66 (95% CI, 0.33-1.32), and a nonsignificant reduction in risk of ACL injury was found in the prevention group (P = .238). No evidence of publication bias was found among studies of either knee or ACL injury prevention programs. CONCLUSION: This systematic review and meta-analysis of ACL and knee injury prevention program studies found a statistically significant reduction in injury risk for knee injuries but did not find a statistically significant reduction of ACL injuries.

A review of arthroscopic classification systems for osteochondritis dissecans of the knee.

Multiple systems for classifying osteochondritis dissecans (OCD) of the knee have been reported. These existing classification systems have some similar characteristics, such as stable lesion/intact articular cartilage and presence of a loose body. However, variations are found in the number of stages and specific lesion characteristics assessed. Currently, no system has been universally accepted. A future classification system should be developed that reconciles the discrepancies among the current systems and provides a clear, consistent, and reliable method for classifying OCD lesions of the knee during arthroscopy.

The relationship of the femoral physis and the medial patellofemoral ligament in children: a cadaveric study.

BACKGROUND: Patellar dislocations are common in skeletally immature athletes, and the medial patellofemoral ligament (MPFL) is an important primary restraint to lateral patellar translation. The relationship between the MPFL femoral origin footprint and femoral physis is unclear. The purpose of this study was to evaluate the MPFL femoral origin footprint and its relationship to the femoral physis in skeletally immature anatomic specimens. METHODS: Six skeletally immature cadaver knee specimens were examined through gross dissection (group A: 1, 11, and 11 mo; and group B: 8, 10, and 11 y). Metallic markers were placed at the center of the MPFL femoral origin footprint. Computed tomography scans for each specimen were analyzed. The MPFL footprint width, and the vertical distances from the center and proximal extent of the MPFL footprint to the medial aspect of the physis were measured. RESULTS: The mean width of the MPFL femoral origin footprint was 0.70 cm (0.48 to 1.09 cm) and 1.12 cm (1.03 to 1.29 cm) for groups A and B, respectively. The mean distance from the center of the MPFL origin footprint to medial aspect of the distal femoral physis was 0.90 cm (0.52 to 1.30 cm) and 0.40 cm (0.00 to 0.86 cm) distal to the physis for groups A and B, respectively. The mean distance from the proximal extent of the MPFL origin footprint to the medial aspect of the femoral physis was -0.55 cm (-0.28 to -1.03 cm) and 0.16 cm (-0.34 to 0.64 cm) for groups A and B, respectively. CONCLUSIONS: All subjects were found to have a center of the MPFL origin footprint at or below the physis. The proximal extent of the MPFL origin footprint was found to extend above the physis in the 2 older specimens. CLINICAL RELEVANCE: The relationship of the MPFL origin footprint to the femoral physis in the skeletally immature is not well understood. These dissections may be useful to surgeons performing MPFL reconstructions in skeletally immature patients.

Fluoroquinolone use in a child associated with development of osteochondritis dissecans.

Several aetiological theories have been proposed for the development of osteochondritis dissecans. Cartilage toxicity after fluoroquinolone use has been well documented in vitro. We present a case report of a 10-year-old child who underwent a prolonged 18-month course of ciprofloxacin therapy for chronic urinary tract infections. This patient later developed an osteochondritis dissecans lesion of the medial femoral condyle. We hypothesise that the fluoroquinolone therapy disrupted normal endochondral ossification, resulting in development of osteochondritis dissecans. The aetiology of osteochondritis dissecans is still unclear, and this case describes an association between fluoroquinolone use and osteochondritis dissecans development.

Osteochondritis dissecans of the ankle in children and adolescents: demographics and epidemiology.

BACKGROUND: Osteochondritis dissecans (OCD) of the ankle is a disorder of the talar or distal tibial subchondral bone and articular cartilage whose incidence in children is not clearly known. PURPOSE: To assess the demographics and epidemiology of OCD of the ankle in children. STUDY DESIGN: Descriptive epidemiologic study. METHODS: A retrospective chart review of an integrated health system was conducted on patients with ankle OCD aged 2 to 19 years from 2007 to 2011, with >1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. Ankle OCD incidence was determined for the group as a whole and by both sex and age group (divided into age groups of 2-5, 6-11, and 12-19 years). The risk for ankle OCD for age group, sex, and ethnicity was assessed using multivariate logistic regression models. RESULTS: A total of 85 patients fit the inclusion criteria, and 71.8% of lesions found were in the medial talus, 56.5% of lesions were right sided, and none were bilateral. No ankle OCD lesions were found in 2- to 5-year-olds. The incidence of ankle OCD in patients aged 6 to 19 years was 4.6 per 100,000 overall and 3.2 and 6.0 per 100,000 for male and female patients, respectively. Patients aged 12 to 19 years represented the vast majority of those with OCD, with an incidence of 6.8 per 100,000 compared with 1.1 per 100,000 in those 6 to 11 years of age. In those aged 6 to 11 and 12 to 19 years, female patients had a respective incidence of 1.5 and 8.9 per 100,000, whereas male patients had a respective incidence of 0.7 and 4.8 per 100,000. The overall female/male ratio of ankle OCD was 1.6:1. Multivariate logistic regression analysis revealed a 6.9 times increased risk for ankle OCD in patients aged 12 to 19 years compared with those aged 6 to 11 years (95% CI, 3.8-12.5; P < .0001), and female patients had a 1.5 times greater risk for ankle OCD than male patients (95% CI, 1.0-2.3; P = .06). On the basis of race and ethnicity, non-Hispanic whites had the highest relative risk for disease and African Americans the lowest risk. CONCLUSION: In this population-based cohort study of pediatric ankle OCD, female patients had a greater incidence of OCD and a 1.5 times greater risk for ankle OCD compared with male patients. Teenagers had nearly 7 times the risk for ankle OCD compared with children 6 to 11 years of age.

Anatomical dissection and CT imaging of the posterior cruciate and lateral collateral ligaments in skeletally immature cadaver knees.

BACKGROUND: Understanding the relationship of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) to the femoral and tibial physes is important to reducing the risk of physeal injury during surgical reconstruction. The purpose of this study was to identify the location of the attachments of the PCL and LCL in skeletally immature cadaveric knee specimens and to determine their position relative to the physes. METHODS: Seven skeletally immature cadaveric knee specimens were examined through gross dissection. These specimens were divided into two groups: infants (an age at death of one month for one specimen and eleven months for two specimens) and children (an age at death of eight years for one specimen, ten years for one specimen, and eleven years for two specimens). Metallic markers were placed at the femoral origins of the PCL and LCL and at the tibial insertion of the PCL. Computed tomography (CT) scans were made for each specimen and analyzed with the use of OsiriX imaging software. The width of the PCL tibial insertion footprint and the height of the PCL femoral origin footprint, the distance from the midpoints of the PCL and LCL femoral origin to the distal femoral physis, and the distance from the PCL insertion footprint midpoint to the proximal tibial physis were measured. RESULTS: The mean distance from the midpoint of the femoral origin footprint of the PCL to the femoral physis was 11.1 mm (range, 10.6 to 11.7 mm) and 18.8 mm (range, 18.2 to 19.2 mm) distal to the physis for infants and children, respectively. The mean distance from the midpoint of the tibial insertion footprint of the PCL to the tibial physis was 3.1 mm (range, 0.0 to 5.7 mm) and 5.8 mm (range, 2.5 to 8.9 mm) proximal to the physis for infants and children, respectively. The mean width of the tibial insertion of the PCL was 5.5 mm (range, 1.1 to 8.3 mm) for infants and 10.2 mm (range, 8.4 to 11.9 mm) for children. The mean distance from the midpoint of the femoral origin of the LCL to the femoral physis was 6.3 mm (range, 3.9 to 7.7 mm) and 5.9 mm (range, 0.0 to 10.0 mm) distal to the physis for infants and children, respectively. CONCLUSIONS: The relationship of the PCL and LCL attachments to physeal structures has not been well described. We found the midpoints of the PCL and LCL femoral origins at or distal to, and the midpoint of the PCL tibial insertion at or proximal to, the respective physis in all specimens. This study with CT-scan correlation provides unique information on the location of ligament attachments in relation to the physes. CLINICAL RELEVANCE: A better understanding of the spatial relationship between the PCL and LCL attachments and their respective physes may help guide drill-hole placement during ligament reconstructions and reduce the risk for iatrogenic physeal injury in skeletally immature patients.

A review of arthroscopic classification systems for osteochondritis dissecans of the knee.

Multiple systems for classifying osteochondritis dissecans (OCD) of the knee have been reported. These existing classification systems have some similar characteristics, such as stable lesion/intact articular cartilage and presence of a loose body. However, variations are found in the number of stages and specific lesion characteristics assessed. Currently, no system has been universally accepted. A future classification system should be developed that reconciles the discrepancies among the current systems and provides a clear, consistent, and reliable method for classifying OCD lesions of the knee during arthroscopy.

Emerging genetic basis of osteochondritis dissecans.

Genome-wide association studies (GWAS) provide an unbiased approach in the identification of genes that increase the risk for osteochondritis dissecans (OCD). Recent GWAS in humans, horses, and pigs are reviewed and genes identified. The identified genes tended to cluster with respect to function and biologic processes. GWAS in humans are a critical next step in the effort to provide a better understanding of the causes of OCD, which will, in turn, allow preventive strategies for treatment of adolescents and young adults who are at risk for the development of degenerative joint disease due to the effects of OCD.

Knee Injuries in Downhill Skiers: A 6-Year Survey Study.

BACKGROUND: Knee injuries account for approximately one third of injuries in skiers. Researchers have proposed several mechanisms of knee injury in skiers. However, the frequencies of these mechanisms have varied in different studies. PURPOSE: To identify the most common knee injury mechanisms in recreational downhill skiers and to assess injury frequencies across several demographics. STUDY DESIGN: Descriptive epidemiology study. METHODS: Over 6 ski seasons, 541 patients with acute knee injuries completed a survey. Patients selected 1 of 6 injury classifications; age, sex, height, weight, years of experience, ability level, and ski binding release were also recorded. RESULTS: The overall injury distribution was valgus-external rotation (32.9%), phantom foot (22.5%), hyperextension (19.0%), boot induced (7.8%), collision (2.2%), and other (15.6%). The phantom foot mechanism was most common in ages 30 to 40 years (36.3% of all injuries within this mechanism; P < .01). Children and adults showed no significant difference in distribution of injury mechanism. Of 80 youth skiers, valgus-external rotation was most common (35.4%), followed by phantom foot (25.3%). Adult and youth skiers who identified as "advanced" skiers had a higher prevalence of valgus-external rotation than did less experienced skiers (51.5% of total valgus injuries; P < .01). Bindings released in 19.3% in adults and 53.7% in youths (P < .01) during injury. Female skiers comprised 60.0% of total respondents, but only 39.7% of injuries occurred in female children (P < .01). CONCLUSION: Valgus-external rotation is the most common injury mechanism for recreational skiers in general. Previous studies have suggested that the phantom foot injury is the most common injury, but in this series, it was the second most common, representing 22.5% of injuries in this study. Individuals between the ages of 30 and 40 years showed an increased risk for the phantom foot mechanism, and the prevalence of injuries was significantly higher for females compared with males in this cohort (P < .01). Children and adults appear to have similar mechanisms for ski-related knee injuries, with valgus-external rotation being most common and advanced skiers having the highest frequency of this mechanism. Binding release was more likely to occur in youth skiers.