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Concept: Osteochondritis dissecans


An increase in interstitial fluid is an expression of bone marrow edema (BME) and osteonecrosis (ON). The exact pathogenetic processes still remain unknown. Treatment options are mainly symptomatic with core decompression as surgical golden standard with immediate pain relief. Recently, it has been shown that intravenous iloprost can be used to achieve a reduction in BME and ON with a considerable improvement in the accompanying symptoms. The effect of intraveneously applied iloprost alone (12 patients) was studied against core decompression alone (12 patients) as well as iloprost following core decompression (12 patients). We could find a significant improvement in HHS, WOMAC score, SF-36 score and VAS 3 months and 1 year after therapeutical intervention in all treatment groups; however, statistically best results were obtained by combination. Concerning the MRI scans, we found a distinct reduction in BME in all groups again favoring the combination. Concerning ON, the results were not as promising as for BME. Intravenous prostacyclin and core decompression as monotherapy are of efficient therapeutical benefit in the treatment of BME, and the combination of both methods, however, seems to be most promising, also in the treatment of ON. Long-term results and higher number of patients are needed for final statements.

Concepts: Bone marrow, Lymphatic system, Avascular necrosis, Diving medicine, Osteochondritis dissecans, Femur head, Epiphysis, Dysbaric osteonecrosis


PURPOSE: Graft hypertrophy is a major complication in the treatment for localized cartilage defects with autologous chondrocyte implantation (ACI) using periosteal flap and its further development, Novocart (a matrix-based ACI procedure). The aim of the present study is to investigate individual criteria for the development of graft hypertrophy by NOVOCART 3D implantation of the knee in the post-operative course of 2 years. METHODS: Forty-one consecutive patients with 44 isolated cartilage defects of the knee were treated with NOVOCART 3D implants. Individual criteria and defect-associated criteria were collected. Follow-up MRIs were performed at 3, 6, 12 and 24 months. The NOVOCART 3D implants were measured and classified. The modified MOCART Score was used to evaluate quality and integration of the NOVOCART 3D implants in MRI. RESULTS: Graft hypertrophy was observed in a total of 11 patients at all post-operative time points. We were able to show that NOVOCART 3D implantation of cartilage defects after acute trauma and osteochondritis dissecans (OCD) led to a significantly increased proportion of graft hypertrophy. No other individual criteria (age, gender, BMI) or defect-associated criteria (concomitant surgery, second-line treatment, defect size, fixation technique) showed any influence on the development of graft hypertrophy. The modified MOCART Score results revealed a significant post-operative improvement within 2 years. CONCLUSION: The aetiology of cartilage defects appears to have a relevant influence for the development of graft hypertrophy. Patients, who were treated with NOVOCART 3D implants after an acute event (acute trauma or OCD), are especially at risk for developing a graft hypertrophy in the post-operative course of two years. LEVEL OF EVIDENCE: Case series, Level IV.

Concepts: Cartilage, Magnetic resonance imaging, Knee, Knee cartilage replacement therapy, Knee replacement, Autologous chondrocyte implantation, Osteochondritis dissecans


OBJECTIVE: To transect blood vessels within epiphyseal cartilage canals and observe whether this resulted in ischaemic chondronecrosis, an associated focal delay in enchondral ossification (osteochondrosis) and pathological cartilage fracture (osteochondrosis dissecans) in the distal femur of foals, with potential translational value to the pathogenesis of juvenile osteochondritis dissecans in children. METHOD: Ten Norwegian Fjord Pony foals were operated at the age of 13-15 days. Two vessels supplying the epiphyseal growth cartilage of the lateral trochlear ridge of the left distal femur were transected in each foal. Follow-up examination was carried out from 1-49 days post-operatively and included plain radiography, macroscopic and histological examination. RESULTS: Transection of blood vessels within epiphyseal cartilage canals resulted in necrosis of vessels and chondrocytes, i.e. ischaemic chondronecrosis, in foals. Areas of ischaemic chondronecrosis were associated with a focal delay in enchondral ossification (osteochondrosis) in foals examined 21 days or more after transection, and pathological cartilage fracture (osteochondrosis dissecans) in one foal examined 42 days after transection. CONCLUSION: The ischaemic hypothesis for the pathogenesis of osteochondrosis has been reproduced experimentally in foals. There are several similarities between osteochondrosis dissecans in animals and juvenile osteochondritis dissecans in children. It should be investigated whether juvenile osteochondritis dissecans also occurs due to a focal failure in the cartilage canal blood supply, followed by ischaemic chondronecrosis.

Concepts: Blood, Heart, Blood vessel, Cartilage, Necrosis, Endochondral ossification, Osteochondritis dissecans, Fjord horse


Osteochondritis Dissecans (OD) is a pathological condition of the subchondral bone and surrounding cartilage of synovial joints, associated with strenuous activity and/or trauma. Reports of OD in archaeological skeletal remains are few and the majority demonstrate low OD prevalence (<1%). A predominantly 19th century skeletal sample from Middenbeemster, the Netherlands, was assessed for OD. The sample included adult individuals of both sexes. There were no definitive OD lesions in non-pedal elements, yet 12.9% of individuals suffered from pedal OD. Few archaeological and clinical reports specify the prevalence of pedal OD. According to the few that do, the Middenbeemster pedal OD prevalence is distinctly high. Several factors could have contributed to this. First, the rural Beemster community was centered around cattle farming, requiring extensive outside work and animal maintenance; thus, increasing the chances of acute/repetitive trauma in the foot. Second, the footwear worn during that period in the Netherlands was the wooden clog. It is suggested that the hard and inflexible clog, which is poor at absorbing shock and limits the movement of the foot, could have resulted in repetitive microtrauma. These two factors combined may have caused a high frequency of OD.

Concepts: Bone, Knee, Joint, Netherlands, Synovial joint, Osteochondritis dissecans, Prostitution in the Netherlands, Clog


Articular cartilage predominantly serves a biomechanical function, which begins in utero and further develops during growth and locomotion. With regard to its 2-tissue structure (chondrocytes and matrix), the regenerative potential of hyaline cartilage defects is limited. Children and adolescents are increasingly suffering from articular cartilage and osteochondral deficiencies. Traumatic incidents often result in damage to the joint surfaces, while repetitive microtrauma may cause osteochondritis dissecans. When compared with their adult counterparts, children and adolescents have a greater capacity to regenerate articular cartilage defects. Even so, articular cartilage injuries in this age group may predispose them to premature osteoarthritis. Consequently, surgery is indicated in young patients when conservative measures fail. The operative techniques for articular cartilage injuries traditionally performed in adults may be performed in children, although an individualized approach must be tailored according to patient and defect characteristics. Clear guidelines for defect dimension-associated techniques have not been reported. Knee joint dimensions must be considered and correlated with respect to the cartilage defect size. Particular attention must be given to the subchondral bone, which is frequently affected in children and adolescents. Articular cartilage repair techniques appear to be safe in this cohort of patients, and no differences in complication rates have been reported when compared with adult patients. Particularly, autologous chondrocyte implantation has good biological potential, especially for large-diameter joint surface defects.

Concepts: Bone, Cartilage, Osteoarthritis, Knee, Joint, Autologous chondrocyte implantation, Osteochondritis dissecans, Articular cartilage repair


Avascular necrosis of the femoral head causes significant morbidity and occurs in up to 20,000 people per year. A variety of nonoperative and operative measures have been trialled however a definitive treatment algorithm is yet to be established. Young adults in many cases have undergone multiple surgical procedures in their lifetime with increasing risks of complications. Less invasive techniques may help reduce the number of operations required and positively influence the natural history of the disease process. Our aim was to navigate the literature and examine the results of electrical stimulation of the femoral head in avascular necrosis.

Concepts: Medicine, Surgery, Fiction, Avascular necrosis, Nature, Osteochondritis dissecans, History of science, Femur head


Legg-Calvé-Perthes' disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

Concepts: Blood vessel, Avascular necrosis, Osteochondritis dissecans, Epiphysis


Avascular necrosis of the femoral head is caused by a multitude of etiologic factors and is associated with collapse with a risk of hip arthroplasty in younger populations. A focus on early disease management with the use of stem cells was proposed as early as 1985 by the senior author (PH). We undertook a systematic review of the medical literature to examine the progress in cell therapy during the last 30 years for the treatment of early stage osteonecrosis.

Concepts: Medicine, Cell division, Stem cell, Hip replacement, Hip, Avascular necrosis, Osteochondritis dissecans, Femur head


Increased intensity of sports activities combined with a decrease in daily physical activity is making overuse injuries in children more common. These injuries are located mainly in the epiphyseal cartilage. The broad term for these injuries is osteochondrosis, rather than osteochondritis, which more specifically refers to inflammatory conditions of bone and cartilage. The osteochondrosis may be epiphyseal, physeal, or apophyseal, depending on the affected site. The condition can either be in the primary deformans form or the dissecans form. While there is no consensus on the etiology of osteochondrosis, multiple factors seem to be involved: vascular, traumatic, or even microtraumatic factors. Most overuse injuries involve the lower limbs, especially the knees, ankle and feet. The most typical are Osgood-Schlatter disease and Sever’s disease; in both conditions, the tendons remain relatively short during the pubescent grown spurt. The main treatment for these injuries is temporary suspension of athletic activities, combined with physical therapy in many cases. Surgery may be performed if conservative treatment fails. It is best, however, to try to prevent these injuries by analyzing and correcting problems with sports equipment, lifestyle habits, training intensity and the child’s level of physical activity, and by avoiding premature specialization. Pain in children during sports should not be considered normal. It is a warning sign of overtraining, which may require the activity to be modified, reduced or even discontinued.

Concepts: Collagen, Foot, Cartilage, Child, Activity, Epiphyseal plate, Osteochondritis dissecans, Warning sign


MicroRNAs (miRNAs) are associated with various pathologic conditions and can serve as diagnostic or therapeutic biomarkers. This study tried to identify the differentially expressed miRNAs to predict the possible pathomechanisms involved in osteonecrosis of the femoral head (ONFH).

Concepts: Pathology, MicroRNA, Avascular necrosis, Osteochondritis dissecans, Femur head