Subchondral defects resembling osteochondrosis dissecans in joint surfaces of the extinct saber-toothed cat Smilodon fatalis and dire wolf Aenocyon dirus.

Skeletal disease may hamper the behavior of large predators both living and extinct. We investigated the prevalence of osteochondrosis dissecans (OCD), a developmental bone disease affecting the joints, in two Ice Age predators: the saber-toothed cat Smilodon fatalis and dire wolf Aenocyon dirus. As published cases in modern Felidae and wild Canidae are rare, we predicted that subchondral defects resembling OCD would be rare in the extinct predators. We examined limb joints in juvenile and adult S. fatalis: 88 proximal humeri (shoulder), 834 distal femora (stifle), and 214 proximal tibiae. We also examined limb joints in juvenile and adult A. dirus: 242 proximal humeri, 266 distal femora, and 170 proximal tibiae. All specimens are from the Late Pleistocene Rancho La Brea fossil locality in Los Angeles, California, USA. While the Smilodon shoulder and tibia showed no subchondral defects, subchondral defects in the Smilodon femur had a prevalence of 6%; most defects were small (<7mm); and nine adult stifles with defects also showed osteoarthritis. Subchondral defects in the A. dirus femur had a prevalence of 2.6%; most defects were large (>12mm); and five stifles further developed mild osteoarthritis. Subchondral defects in the A. dirus shoulder had a prevalence of 4.5%; most defects were small, and three shoulders developed moderate osteoarthritis. No defects were found in the A. dirus tibia. Contrary to our prediction, we found a high prevalence of subchondral defects in the stifle and shoulder of S. fatalis and A. dirus resembling OCD found in humans and other mammals. As modern dogs affected by OCD are highly inbred, this high prevalence in the fossil taxa may suggest that they experienced inbreeding as they approached extinction. The deep-time history of this disease supports the need for monitoring of animal domestication, as well as conservation, to avoid unexpected surges in OCD under conditions like inbreeding.

The mid-term effect of Osgood-Schlatter disease on knee function in young players from elite soccer academies.

BACKGROUND: The aim of the study was to evaluate the effect of Osgood-Schlatter disease (OSD) on knee joint function in elite young soccer players. Our hypothesis was that knee joint function in elite young soccer players was impaired following OSD compared with soccer players with no history of OSD. METHOD: In young male soccer players (n = 36) from elite academies (mean ±SD, age: age: 15,3 ± 1,7 years; height: 1,7 ± 0,06 m; weight: 63,5 ± 8 kg; BMI: 20,7 ± 2). The duration between the completion of treatment or the last complaint to the study commencement was 31 ± 19 months. RESULTS: The average treatment duration of OSD among study participants was 18,5 ± 12 days (95%, 14-23), and the disease most often manifested in winter and spring, 33% and 31% of cases, respectively. Soccer players with a history of OSD were statistically different in IKDC and KOOS scores when compared with soccer players with no previously reported OSD (Mann-Whitney, p < 0,0001). The soccer players with a history of OSD also use NSAIDs more frequently compared with soccer players with no history of OSD (36% vs 3% respectively). CONCLUSIONS: OSD among young soccer players, when symptoms resolve, continue about one month and they can return to regular training and participation in games. Wherein, the negative effects in knee joint function were significantly more likely in soccer players with previous OSD history when compared with their peers with no history of OSD. While oral non-steroidal anti-inflammatory drugs was also more widely employed in soccer players with previous OSD history. Potentially this may lead to performance deficits and disadvantages for their future careers and coaches and physicians should be informed.

Angular limb deformities due to distal radial physeal osteochondrosis in farmed deer stags in New Zealand.

CASE HISTORY: Three different farms reported cases of angular limb deformities (ALD) in rising 2-year-old velvet, mostly red deer (Cervus elaphus), stags with the earliest recorded cases occurring in 2010. Farm 1 reported a prevalence of 10-35%, farm 2, 5-11.5%, and farm 3, 2-5%. Farms 1, 2, and 3 are located in South Canterbury, northern Southland, and the Waikato, respectively. CLINICAL FINDINGS: Affected animals developed ALD, with predominantly varus forelimb (bowed) deformities. On all farms serum calcium and phosphorus concentrations in affected animals were normal. Serum and liver copper concentrations were variable across the period of the study and between farms. Although some measurements were below the reference ranges, there was no evidence for a statistical association with the prevalence of abnormalities. PATHOLOGICAL FINDINGS: The distal radius from 25 affected and four control red and red-wapiti (Cervus canadensis) cross deer from Farm 1 in 2010/2011, two affected red deer from Farm 2 in 2016, and one affected red deer from Farm 3 in 2021, were examined. The most consistent lesions were present in the distal radial physis, most commonly the lateral edge. There was mild-to-severe segmental thickening of the physis and, in some animals, physeal cartilage was duplicated with both sections of physis varying in thickness. Microscopically, in severely affected animals there was massive segmental thickening of physeal cartilage which often contained large cystic cavities. The cartilage matrix was eosinophilic and showed a loss of metachromatic staining with toluidine blue. In less severe cases, necrotic physeal vessels were present, consistent with vascular failure. In more chronic cases, there was duplication of the physis, the two layers being separated by a combination of normal trabecular bone and dense fibrous connective tissue. DIAGNOSIS: Physeal osteochondrosis. CLINICAL RELEVANCE: Osteochondrosis has a multifactorial aetiology and we propose that an increased requirement for nutrients for velvet production and increased weight-bearing stress (behaviour and rapid weight gain) may lead to progression of osteochondrosis and ALD in these deer. The involvement of periods of copper deficiency is unclear at this time.

A method for labelling lesions for machine learning and some new observations on osteochondrosis in computed tomographic scans of four pig joints.

BACKGROUND: Osteochondrosis is a major cause of leg weakness in pigs. Selection against osteochondrosis is currently based on manual scoring of computed tomographic (CT) scans for the presence of osteochondrosis manifesta lesions. It would be advantageous if osteochondrosis could be diagnosed automatically, through artificial intelligence methods using machine learning. The aim of this study was to describe a method for labelling articular osteochondrosis lesions in CT scans of four pig joints to guide development of future machine learning algorithms, and to report new observations made during the labelling process. The shoulder, elbow, stifle and hock joints were evaluated in CT scans of 201 pigs. RESULTS: Six thousand two hundred fifty osteochondrosis manifesta and cyst-like lesions were labelled in 201 pigs representing a total volume of 211,721.83 mm3. The per-joint prevalence of osteochondrosis ranged from 64.7% in the hock to 100% in the stifle joint. The lowest number of lesions was found in the hock joint at 208 lesions, and the highest number of lesions was found in the stifle joint at 4306 lesions. The mean volume per lesion ranged from 26.21 mm3 in the shoulder to 42.06 mm3 in the elbow joint. Pigs with the highest number of lesions had small lesions, whereas pigs with few lesions frequently had large lesions, that have the potential to become clinically significant. In the stifle joint, lesion number had a moderate negative correlation with mean lesion volume at r = - 0.54, p < 0.001. CONCLUSIONS: The described labelling method is an important step towards developing a machine learning algorithm that will enable automated diagnosis of osteochondrosis manifesta and cyst-like lesions. Both lesion number and volume should be considered during breeding selection. The apparent inverse relationship between lesion number and volume warrants further investigation.

Osgood-Schlatter Disease in youth elite football: Minimal time-loss and no association with clinical and ultrasonographic factors.

BACKGROUND: Osgood-Schlatter Disease is the most common cause of knee pain in youth. Scientific research in youth elite football is limited. OBJECTIVES: To assess clinical and ultrasonographic factors associated with Osgood-Schlatter Disease and calculate point prevalence of clinical diagnosis and time-loss in youth elite male football. STUDY DESIGN: Nested case-control study and cross-sectional prevalence study; Level of evidence: 3. METHODS: We obtained data during the pre-season periodic health evaluation. Osgood-Schlatter Disease diagnosis was defined as (1) athlete-reported anterior knee pain and (2) clinical confirmation by pain provocation at the tibial tuberosity. Time-loss was defined as inability to participate in team training and/or competition. For the nested-case control study, we examined clinical and ultrasonographic factors in the U13 to U16 teams. We matched on calendar-age. The clinical factors were: self-reported history of Sever's disease, growth measures, leg muscles flexibility and strength and ultrasonographic bone maturity stages according to Ehrenborg, For the cross-sectional study, we included players of the U13 to U19 teams to calculate the point prevalence. RESULTS: The case-control study consisted 30 players and the cross-sectional study 127 players. Previous Sever's disease was strongly associated with Osgood-Schlatter Disease (OR = 16.8; p = 0.02; 95% CI = 1.6-174.5). None of the other clinical or ultrasonographic factors were associated. The point prevalence was 17% and 80% had no time-loss despite presence of clinical symptoms. CONCLUSION: Considering the 16.8OR, previous Sever's disease indicates a strong association with Osgood-Schlatter Disease. Although generally suggested, growth velocity and bone maturity are not associated in an age-matched comparison.

Incidence and management of Osgood-Schlatter disease in general practice: retrospective cohort study.

BACKGROUND: Osgood-Schlatter disease (OSD) is a non-traumatic knee problem that is primarily observed in sports-active children and adolescents aged 8-15 years. AIM: To determine the incidence of OSD and to gain an insight into the management of children and adolescents with OSD in general practice. DESIGN AND SETTING: A retrospective cohort study was conducted using a healthcare database containing full electronic health records of over 200 000 patients in general practice in and around the Dutch city of Rotterdam. METHOD: Patients with a new diagnosis of OSD from 1 January 2012 to 31 December 2017 were extracted using a search algorithm based on International Classification of Primary Health Care coding and search terms in free text. Data on the management of OSD were manually interpreted. RESULTS: The mean incidence over the study period was 3.8 (95% confidence interval [CI] = 3.5 to 4.2) per 1000 person-years in those aged 8-18 years. Boys had a higher incidence rate of 4.9 (95% CI = 4.3 to 5.5) compared with girls (2.7, 95% CI = 2.3 to 3.2). Peak incidence was at 12 years of age for boys and 11 years for girls. Advice was the most commonly applied strategy (55.1%), followed by rest (21.0%), referral for imaging (19.5%), and physiotherapy (13.4%). CONCLUSION: To the authors' knowledge, for the first time the incidence of OSD has been calculated using GP electronic medical files. There is a discrepancy, especially for imaging and referral to a medical specialist, between the current Dutch general practice guidelines and how GPs actually manage the condition in clinical practice.

The Osgood-Schlatter disease: a large clinical series with evaluation of risk factors, natural course, and outcomes.

PURPOSE: The aims of this prospective study were to define sport specific incidence rates in a large Osgood-Schlatter-disease group, to follow the natural course, and to determine late effects, i.e., changes in sport activities and resting pain. METHODS: A total of 126 consecutive patients with functional pain in and after physical activity and local TT swelling were included in a longitudinal study. Physical examination, ultrasound, and a lateral X-ray were performed in a standardized clinically common manner. Sport participation, growth rate, BMI, and muscle status were recorded and assigned statistically. Follow-up took place after subsidence of functional pain. RESULTS: Exactly 101 boys and 25 girls showed a mean age at diagnosis of 12.8 years (boys 13.2, girls 11.4 years) complaining an average period of pain of 6.7 months before diagnosis. A sport distribution displayed 64 football (soccer) players, 18 basketball players, seven athletes in track and field, six martial arts sportsmen, and five handball players, all participating in organized sport clubs, 16 patients in other and ten patients in no sports. The standing leg was affected in 69.6% of all football players, whereas the other disciplines did not show any significance. A total of 105 patients could be followed up after a median of 3.6 years; six of them were still symptomatic. Final outcome could be recorded for 99 patients (79 boys, 20 girls). Osgood-Schlatter disease (OSD) symptoms in or after sport activity were reported to last an average of 19.1 months (3-48 months) without differences according to sex nor sport. Exactly 50% of the patients may expect to be free of functional symptoms after the 16th month, 75% after the 25th month. A total of 78.8% of the patients still complained of persistent but not impairing pain in kneeling or on direct TT contact. Exactly 28.3% of all patients responded having switched their sport activity to other disciplines due to OSD. CONCLUSION: OSD affects mainly adolescent boys active in football and basketball and represents a structural answer to repeated biomechanical stress. Only in football, the statically dominant side is more prone to develop OSD. Age at onset, growth rate, BMI, and muscle imbalance are not significantly predisposing. OSD runs a self-limiting course without specific treatment.

Co-occurrence of Blount's disease and Legg-Calvé-Perthes disease: is obesity a factor?

Legg-Calvé-Perthes disease (LCPD) and Blount's disease share a similar presenting age in addition to similar symptoms such as limp or knee pain. A little overlap is mentioned about both diseases. We sought to present cases of children having both conditions to discuss the implications of this co-occurrence on diagnosis and management. After institutional review board approval, we retrospectively reviewed records of four children who developed both Blount's disease and LCPD. Patient details and outcomes were analyzed. Radiographs were evaluated for the lateral pillar classification, Stulberg classification, tibial metaphyseal-diaphyseal angle and tibiofemoral angle. Two of the cases were initially diagnosed with Blount's disease and subsequently developed Perthes, one case presented initially with both disorders and the final case had Perthes followed by Blount's. Three children were obese and one was overweight. The common symptom to all patients was an abnormal gait, which was painless in two children and painful in two. Blount's disease required surgery in three children. Radiographs showed Lateral Pillar B, B/C border and C hips, and the final Stulberg was stage II (n = 2) or stage IV (n = 2). Obesity is associated with Blount's disease and LCPD, so obese children can be at an increased risk of developing both disorders. Therefore, a child with Blount's disease who has persistent, recurrent or worsening symptoms such as gait disturbance or thigh or knee pain might benefit from a careful physical exam of the hips to prevent a delayed or even missed LCPD diagnosis.

The dimensions of "failed back surgery syndrome": what is behind a label?

BACKGROUND: The term failed back surgery syndrome (FBSS) has been criticized for being too unspecific and several studies have shown that a variety of conditions may underlie this label. The aims of the present study were to describe the specific symptoms and to investigate the primary and secondary underlying causes of FBSS in a contemporary series of patients who had lumbar spinal surgery before. METHODS: We used a multilevel approach along three different axes defining symptomatic, morphological, and functional pathology dimensions. RESULTS: Within the study period of 3 years, a total of 145 patients (74 f, 71 m, mean age 51a, range 32-82a) with the external diagnosis of FBSS were included. Disk surgery up to 4 times and surgery for spinal stenosis up to 3 times were the commonest index operations. Most often, the patients complained of low back pain (n = 126), pseudoradicular pain (n = 54), and neuropathic pain (n = 44). Imaging revealed osteochondrosis (n = 61), spondylarthrosis (n = 48), and spinal misalignment (n = 32) as the most frequent morphological changes. The majority of patients were assigned at least to two different symptomatic subcategories and morphological subcategories, respectively. According to these findings, one or more functional pathologies were assigned in 131/145 patients that subsequently enabled a specific treatment strategy. CONCLUSIONS: FBSS has become rather a vague and imprecisely used generic term. We suggest that it should be avoided in the future both with regard to its partially stigmatizing connotation and its inherent hindering to provide individualized medicine.

The femoral deformity in Blount's disease: a comparative study of infantile, juvenile and adolescent Blount's disease.

An associated femoral deformity in patients with Blount's disease is not commonly described in the literature. The objective of this study is to establish the presence and magnitude of deformity in the coronal plane of the distal femur in children of all ages with Blount's disease and compare this to a matched cohort of children from the same population. This was a retrospective review of patients from an academic hospital. A control group was established by matching for age and gender from a group of unaffected patients with mid to proximal third femur fractures or controls at the same hospital. Study participants were categorized by age at onset of deformity as follows: infantile (<4 years), juvenile (4-10 years) and adolescent (>10 years). The measurements of the anatomic lateral distal femoral angle (aLDFA) were recorded and the Wilcoxon rank-sum test was used to determine statistically significant differences in the LFDA between children with Blount's disease and those without. Seventy-two Black African children were included in the study with 118 affected limbs (27 infantile, 55 juvenile and 36 adolescent). The overall average aLDFA for all patients with Blount's disease was 87° (range 73-100°). Overall, children with Blount's disease had a higher aLDFA than children without (87° vs. 82°). There was a significant association between LDFA in the control group and children with Blount's disease in each of the three groups. This study found distal femoral varus deformity to be present in all groups of children with Blount's disease. In this study population, it was most significant in the infantile and adolescent groups when compared to a control group from the same population. Although further studies are required, the surgeon must always assess the distal femoral component in treating children with Blount's disease.

Blount Disease and Obstructive Sleep Apnea: An Under-recognized Association?

BACKGROUND: Obesity is strongly associated with both Blount disease and obstructive sleep apnea (OSA). Obesity increases risks for anesthetic and postoperative complications, and OSA can further exacerbate these risks. Since children with Blount disease might have both conditions, we sought to determine the perioperative complications and the prevalence of OSA among these children. METHODS: Patients younger than 18 years undergoing corrective surgery for Blount disease were identified from 2 sources as follows: a retrospective review of records at a single institution and querying of the Kids' Inpatient Database, a nationally representative database. RESULTS: At our institution, the prevalence of OSA among patients surgically treated for Blount disease was 23% (42/184). Blount patients were obese (100%), and predominately African American (89%), and male (68%). Patients were treated for OSA before surgery, and 2 patients (1%) had postoperative hypoxemia. In contrast, of 1059 cases of Blount disease from the Kids' Inpatient Database, 3% were diagnosed with OSA. In total, 4.4% of all the Blount children experienced complications, including hypoxemia, respiratory insufficiency, atelectasis, and arrhythmias. Complications were associated with 4.3 additional days of hospitalization (P<0.0001) and 39% additional hospital charges (P=0.002). CONCLUSIONS: Data from the national database showed a low rate of OSA prevalence but high respiratory and OSA-associated complications, perhaps indicating that OSA may be underdiagnosed in children with Blount disease. Affected patients, especially ones with untreated OSA, sustain increased surgical morbidity. A high index of suspicion and preoperative planning helps alleviate the burden of OSA among these patients. LEVEL OF EVIDENCE: Level III-case-control study.

Conservative treatment of Osgood-Schlatter disease among young professional soccer players.

BACKGROUND: The present-day conservative treatment algorithms of Osgood-Shlatter Disease (OSD) are often inadequate for young athletes because they require extremity immobilization and avoidance of sports, and hence the longer duration of rehabilitation. Therefore, the development of safe and efficacious treatment protocols for young athletes is of great practical importance. THE AIM OF THE STUDY: The aim of the study was to assess the efficacy and safety of the conservative treatment of Osgood-Schlatter disease in young professional soccer players. MATERIALS AND METHODS: Medical records of young soccer players from two different Russian soccer-academies from the period January 2016-July 2019 were analyzed in a retrospective cohort study. Trauma records of young soccer players aged 11-15 years were included in the analysis. Statistical analysis was performed using IBM SPSS Statistics software, 23.0. Descriptive statistics tools were applied for the analysis. RESULTS: A total of 280 soccer players were included in the study. The aged ranged between 11 and 15 years. Ten percent of players (n = 28, mean age 12.9 ± 1.3) were diagnosed with OSD during the observation period. The mean OSD treatment duration was 27.3 ± 13.9 days. Bilateral symptoms were observed in 42.9% of cases, and unilateral symptoms in 57.1%. In 53.6% of players, the first manifestation of OSD symptoms was observed during wintertime. All players were training on artificial turf playing fields. Conservative treatment without immobilization was applied to all patients. It included kinesiotherapy for quadriceps muscle lengthening and physiotherapy as well as gradual increase of physical activity. A total of 35.7% of players reported having discomfort upon resuming regular training, which caused some restrictions in exercise. However, the symptoms resolved spontaneously with time. Surgical treatment or complete avoidance of exercise was not used in any of the patients. CONCLUSION: High incidence of OSD was revealed among young soccer players of the leading Russian soccer academies. The OSD most commonly occurred during wintertime. Conservative treatment of OSD-i.e., physiotherapy and kinesiotherapy-enabled disease-free resuming of sports activity for the majority of patients.

Alleged predisposing dietary factors fail to increase the incidence of osteochondrosis-like lesions in growing pigs at 14 and 24 wk of age.

Early lesions of osteochondrosis (OC) are exhibited by regions of cartilage retention along the growth plate and articular cartilage. Progression of OC lesions may impair locomotion and necessitate euthanasia in adherence to animal welfare guides. Little is known about the role of nutrition in the initiation and early stages of OC. However, dietary components are commonly implicated as predisposing factors. In this study, diets were altered as an attempt to induce early stage OC lesions under controlled conditions. At 8 wk of age, 96 crossbred gilts (body weight [BW] = 17.4 ± 0.18 kg) were randomly assigned to one of four corn-soybean meal-based diets (four pens per diet, six pigs per pen) to assess diet effects on the number and volume of OC lesions in the distal femur. Diets included a non-pelleted control diet (Ctl); Ctl plus 20% glucose (Glc); the Ctl with increased concentrations of lysine, Ca, and P (+CaP); and the +CaP diet in a pelleted form (PEL). Femurs were collected from pigs euthanized at either 14-wk (Wk 14) or 24-wk (Wk 14) of age for assessments of OC lesions. Based on a mixed model analysis with pen as the experimental unit, dietary treatments did not affect final BW (129.3 ± 3.8 kg) or average daily gain (ADG) (1.00 ± 0.03 kg/d) over the trial. As expected, pigs fed PEL and Glc diets were more efficient (P < 0.05) in feed conversion compared with Ctl and +CaP. Using femurs as the experimental unit at Wk 14 (collected from two of the six pigs per pen), bone mineral content, determined by dual-energy x-ray absorptiometry scans, was greater (P < 0.05) in pigs fed +CaP and PEL than Ctl or Glc diets; however, only +CaP group differed (P < 0.05) at Wk 24 (collected from four pigs per pen). Computed tomography (CT) scans of femurs were reconstructed as three-dimensional images to allow detection of the number, volume, and surface area of lesions in distal growth plates. At Wk 14, pigs fed Ctl had fewer number of lesions (P < 0.05); however, no differences were detected among dietary treatments in lesion volume or lesion surface area. Pigs had fewer lesions at Wk 24 than Wk 14; however, differences were not detected among dietary treatments. At Wk 24, pigs fed Ctl diets had the greatest lesion volume among dietary treatments (P < 0.05). In conclusion, none of the pigs exhibited symptoms of lameness regardless of dietary treatment or OC lesion traits. Diet modifications due to pelleting or inclusion of rapidly digestible ingredients, such as glucose, did not increase prevalence or size of OC lesions. Image analysis of CT scans was a reliable method to quantify the number, size, and location of OC lesions.

Insight into the possible aetiologies of Blount's disease: a systematic review of the literature.

Blount's disease or bowed leg deformity, is a unilateral or bilateral growth deformity of the medial proximal tibia that leads to a tibial varus deformity. A distinction can be made in an early and late onset type. The disease seems to have a predisposition for certain descends. Since the first publication of Blount's disease, different hypotheses on the aetiology are proposed but no consensus exists. The objective of this study is to provide an overview of the available hypotheses on the aetiology of Blount's disease since its first description and assessment of the available level of evidence, the quality of evidence and the occurrence of bias supporting these individual hypotheses. A systematic search according to the PRISMA statement was conducted using PubMed, MEDLINE, EMBASE and the Cochrane Library using a broad combination of terminology to ascertain a complete selection. Proper MESH search criteria were formulated and the bibliographic search was limited to English and Dutch language articles. Articles with no mention of aetiology or a disease related to Blount's were excluded. Level of evidence and types of bias were assessed. Thirty-two articles that discuss the aetiology of Blount's disease were selected. A variety of hypotheses was postulated in these articles with most research in the field of increased mechanical pressure (obesity, early walking age) and race (descend). Blount's disease most likely has a multifactorial origin with influence of genetic and racial predisposition, increased mechanical pressure on the growth plate as a consequence of obesity or early walking age and possibly also nutrition. However, the exact aetiology remains unclear, the probable explanation is that multifactorial factors are all contributing to the development of Blount's disease. Histological research has shown that a disorganization of bone and cartilage structures on the medial side of the proximal tibial physis is present in patients with Blount's disease. Based on the available evidence on the aetiology of Blount's disease, we conclude that it is multifactorial. Most papers focus only on one hypotheses of Blount's disease occurrence and all are characterized as low level of evidence. There seems to be a preference for certain descends. Further research on especially genetic predisposition is needed to provide more insight in this factor of Blount's disease.

Osgood-Schlatter disease: a 2020 update of a common knee condition in children.

PURPOSE OF REVIEW: Osgood-Schlatter disease (OSD) is one of the most common causes for anterior knee pain in children and adolescents resulting from a traction apophysitis of the tibial tubercle. While a peak in boys aged 12-15 years old was well documented, there seems to be no difference in sex distribution nowadays. This may result from increased participation of young females in high-impact sports. This review provides an up-to-date account on contemporary prophylaxis as well as diagnostic and therapeutic approaches. RECENT FINDINGS: Numerous studies have examined risk factors for OSD. These include body weight, muscle tightness, muscle weakness during knee extension and flexibility of hamstring muscles. In particular, shortening of the rectus femoris may substantially alter biomechanical functions of the knee. Conservative management remains successful in over 90% of patients. However, if disabling symptoms and pain persistent after physeal closure, operative treatment may be necessary. SUMMARY: OSD is a mostly self-limiting apophysitis of the tibial tubercle and the adjacent patella tendon in young active patients with open physis. Prevention strategies include quadriceps and hamstring stretching and therefore should be implemented in everyday practice routines for children who partake in regular sports activities.

Slipped capital femoral epiphysis and Blount disease as indicators for early metabolic surgical intervention.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) and Blount disease are strongly associated with pediatric obesity, yet they have only recently been identified as indications for consideration of metabolic and bariatric surgery (MBS). OBJECTIVES: To describe the relationships between pediatric obesity, MBS, SCFE, and Blount disease. SETTING: Nationwide database. METHODS: The national inpatient sample was used to identify patients ≤20 years old with obesity who underwent MBS from 2007 to 2016. Presence of SCFE and Blount disease was similarly extracted. RESULTS: The overall prevalence of SCFE and Blount disease among patients ≤20 years old is .02% for both (14,976, 11,238 patients, respectively) with no statistically significant change over the study period (P = .68, .07, respectively). The rates of SCFE and Blount disease in children with and without obesity are .46% versus .02% and .36% versus .01%, respectively (P < .001 for both). The mean age of patients with SCFE and obesity was 12 years old, while the mean age of those without obesity was 12.2 years old (P = .03). None of the children with obesity and SCFE underwent MBS. Similarly, the mean age of patients with Blount disease and obesity was 12.6 years old, while the mean age of those without obesity was 13.1 years old. Moreover, the mean age of children with Blount disease and obesity who underwent MBS was 16 years old (P < .001). CONCLUSIONS: Orthopedic complications remain a persistent problem in the pediatric population who suffer from obesity. Despite being diagnosed at a young age, patients with SCFE and/or Blount disease are not undergoing MBS until their later adolescent years, potentially leading to unnecessary disease progression or recurrence of disease after orthopedic interventions. Therefore, SCFE and Blount disease should be considered indications for early consideration of MBS in this pediatric population.

Double-Stranded RNA Is a Novel Molecular Target in Osteomyelitis Pathogenesis: A Translational Avian Model for Human Bacterial Chondronecrosis with Osteomyelitis.

Osteomyelitis remains a serious inflammatory bone disease that affects millions of individuals worldwide and for which there is no effective treatment. Despite scientific evidence that Staphylococcus bacteria are the most common causative species for human bacterial chondronecrosis with osteomyelitis (BCO), much remains to be understood about the underlying virulence mechanisms. Herein, we show increased levels of double-stranded RNA (dsRNA) in infected bone in a Staphylococcus-induced chicken BCO model and in human osteomyelitis samples. Administration of synthetic [poly(I:C)] or genetic (Alu) dsRNA induces human osteoblast cell death. Similarly, infection with Staphylococcus isolated from chicken BCO induces dsRNA accumulation and cell death in human osteoblast cell cultures. Both dsRNA administration and Staphylococcus infection activate NACHT, LRR and PYD domains-containing protein (NLRP)3 inflammasome and increase IL18 and IL1B gene expression in human osteoblasts. Pharmacologic inhibition with Ac-YVAD-cmk of caspase 1, a critical component of the NLRP3 inflammasome, prevents DICER1 dysregulation- and dsRNA-induced osteoblast cell death. NLRP3 inflammasome and its components are also activated in bone from BCO chickens and humans with osteomyelitis, compared with their healthy counterparts. These findings provide a rationale for the use of chicken BCO as a human-relevant spontaneous animal model for osteomyelitis and identify dsRNA as a new treatment target for this debilitating bone pathogenesis.

Fragmentation of the dorsal distal aspect of the talus on weanling survey and pre-sale radiographs of juvenile Thoroughbreds: prevalence and 2- and 3-year-olds racing performance.

BACKGROUND: Fragmentation of the dorsal aspect of the distal talus (FDDT), at the dorsolateral articular margin of the proximal intertarsal joint (PITJ) on pre-sale radiographs of yearling Thoroughbreds has not been previously described and data to support decisions made by veterinarians to predict future racing potential of horses with these lesions are lacking. METHODS: In this retrospective case-control study we aimed to determine the prevalence of FDDT in juvenile Thoroughbreds and to report their race records. From a database of survey and repository radiographic examinations of 5709 horses, 36 with FDDT were identified. RESULTS: The prevalence of FDDT was 0.63% (36/5709; 95%CI 0.44, 0.87), compared with 5.01% (286/5709; 95%CI 4.46, 5.61) for osteochondrosis of the distal intermediate ridge of the tibia in the same population. In most cases, a single oval-shaped fragment 1-12 mm in diameter was present. When comparing cases with matched controls, there were no significant differences in mean sale price, whether horses started in a trial or race and mean number of starts, wins, places and prize money when 2- and 3-years old. CONCLUSION: FDDT did not appear to affect racing performance, although a larger-scale study is warranted to confirm this finding.

Prevalence of osteochondral lesions in the fetlock and hock joints of Standardbred horses that survived bacterial infection before 6 months of age.

BACKGROUND: Young Standardbred horses frequently develop fragments in joints. Some fragments represent osteochondrosis; others are considered developmental, but it is uncertain whether they result from preceding osteochondrosis. Osteochondrosis occurs as a consequence of failure of the cartilage canal blood supply and ischaemic chondronecrosis. In heritably predisposed foals, failure was associated with incorporation of vessels into bone. However, bacterial vascular failure was also recently documented in foals suffering spontaneous infections, proving that bacteria can cause osteochondral lesions in foals up to 150 days old. The aim was to determine prevalence of fetlock and hock lesions at screening age in Standardbred horses that survived infections before 6 months of age, and compare this to prevalence reported in the literature. METHODS: The material consisted of 28 Standardbred horses; 17 males and 11 females that presented and were diagnosed clinically with bacterial infections from 1 to 150 days of age (average: 41.3 days). A screening set of 8 radiographic projections was available from all 28 horses at 7-85 months of age (average: 23.6 months). Lesion prevalence was compared to three previously reported Standardbred cohorts. RESULTS: Osteochondral lesions were detected in one or more joints of 19/28 horses (67.9%); in the fetlock joint of 14/28 horses (50%) and the hock joint of 11/28 horses (39.3%). These prevalences were ≥ 2 x higher than the corresponding prevalences in the comparison cohorts, and statistically significantly so in 5:6 comparisons (p-values from < 0.00001 to 0.01). In the sepsis cohort, there were an average of 2.3 affected joints and 2.5 lesions per affected horse, whereas there in the one comparable literature cohort were an average of 1.5 affected joints and 1.7 lesions per affected horse. CONCLUSIONS: Standardbred horses that survived bacterial infections before 6 months of age had more osteochondral lesions than literature comparison cohorts at screening age. The implication was that some of the lesions in this group were caused by bacteria. It may become necessary to develop methods for differentiating between acquired, septic and aseptic, heritably predisposed lesions.

Incidence and characteristics of juvenile tarsocrural osteochondrosis in purebred Angus bulls.

Osteochondrosis (OC) of the bovine tarsus has been suggested to contribute to osteoarthritis. The objective of this prospective cohort study was to provide data specific to the Angus breed. Clinical and radiographic exams evaluating OC lesions, effusion and osteoarthritis were performed in 50 purebred bull calves at three time points between 5.8 and 21 months of age. The likelihood of OC was lower at a median age of 12.4 months (P<0.001), primarily due to resolution of distal talus changes (P<0.01). Significant associations were observed between medial malleolus lesions and effusion at median age of 7.4 months (P<0.001). This study suggests that clinical and radiographic screening performed at approximately one year of age may be beneficial in detecting tarsal OC lesions in Angus breeding herds.