Unique Anatomic Feature of the Posterior Cruciate Ligament in Knees Associated With Osteochondritis Dissecans

Juvenile Osteochondritis Dissecans: A Case Report

(1) Background: This report aims to illustrate the development, progression, diagnosis, and treatment of chronically present articular surface lesions. (2) Methods: In this report, two patients are described from the point of the initial presentation of symptoms to surgical consultation based on radiologic findings. These patients underwent corrective surgery in the form of mosaicplasty to repair lesions present on the articular surface and the underlying subchondral bone. (3) Discussion: Diagnosing juvenile OCD remains challenging due to its variable clinical presentation and minute radiologic discoveries. X-rays are useful; however, the gold standard remains arthroscopy, which can be both diagnostic and therapeutic. Future prospects include the use of novel sonographic methods and the use of artificial intelligence within the given modalities. (4) Conclusions: The detailed imaging provided by MRI, combined with the insights from X-rays and potentially other modalities, allows for a nuanced understanding of this disease. This comprehensive approach ensures that treatment decisions are well-informed, optimising outcomes for young patients with this condition.

Juvenile Osteochondritis Dissecans: Current Concepts

Osteochondritis dissecans (OCD) primarily damages the subchondral bone, leading to damage to the articular cartilage. Juvenile OCD (JOCD) of the knee is limited to skeletally immature and young patients with open growth plates on radiographs. We conducted a review of PubMed articles up until March 16, 2024, using a combination of the following keywords: knee, juvenile, and osteochondritis dissecans. This narrative review included a total of 56 relevant articles that investigated the etiology, incidence, clinical presentation, imaging, classification, and treatment of JOCD of the knee in patients less than 20 years of age. The exact etiology is controversial. Most authors believe that the disease involves multiple theories, such as ischemia, recurrent trauma, and genetic predisposition. Radiographs, the first imaging study in this patient group, cannot determine the stability or instability of the surface cartilage of the OCD lesion. As a result, MRI has become a recommended diagnostic method for determining OCD stability and providing important information for determining a treatment plan. For stable JOCD lesions, nonsurgical treatment is often advised. For unstable and stable lesions that do not respond to nonsurgical treatment, several surgical techniques with good healing rates are available.

A Comparative Analysis of Osteochondritis Dissecans and Avascular Necrosis: A Comprehensive Review

Musculoskeletal disorders, standing as the fifth leading cause of disability-adjusted life years globally, present significant challenges in orthopedics. Osteochondritis dissecans (OCD) and avascular necrosis (AVN) are distinct but closely related conditions within this spectrum, impacting patients' quality of life with pain, limited mobility, and dysfunction. OCD, involving cartilage and bone detachment in joints, predominantly affects young athletes, but its exact etiology and optimal management remain subjects of ongoing research. Conversely, AVN, marked by bone tissue death due to compromised blood supply, is linked to systemic factors like corticosteroid use and traumatic injuries. Diagnosis for both conditions relies on radiography and magnetic resonance imaging. Conservative treatment for AVN includes the use of a cane or crutches, pharmacological therapy, or physical therapy. On the other hand, in OCD, the primary approach is activity/sports restriction. Surgical treatment options for AVN patients encompass core decompression, bone grafting, or, in the most advanced cases, total hip arthroplasty. OCD may be surgically treated through subchondral drilling or fixation of unstable lesions. Advanced cases of OCD involve cartilage salvage with resurfacing techniques. The presentation of differences between these conditions enhances our understanding, facilitating improved diagnosis and management strategies.

Osteochondritis dissecans of the knee: Epidemiology, etiology, and natural history

Osteochondritis dissecans of the knee is a disease that typically affects skeletally immature patients. Clinically manifested with knee pain, limping, and joint disfunction, this condition has remained misunderstood and undervalued for a long period. Although being a rare condition, its awareness is of utmost clinical interest because of the possible severe consequences it can bring when misrecognized or inadequately treated. Its etiology remains unclear and is still debated. Many theories have been proposed, including inflammation, local ischemia, subchondral ossification abnormalities, genetic factors, and repetitive mechanical microtrauma, with a likely interplay of the same. This review article aims to deliver and discuss current and up-to-date concepts on epidemiology, etiology, and natural history of this pediatric condition. Level of evidence: level V.

Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes

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Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis.

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While generally considered an idiopathic phenomenon, various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition.

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Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging.

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Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and operative for those who have had failure of conservative management or have unstable lesions.

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Clinical practice guidelines have been limited by a paucity of high-level evidence, but a multicenter effort is ongoing to develop accurate and reliable classification systems and multimodal decision-making algorithms with prognostic value.

Osteochondritis Dissecans of the Knee: Etiology and Pathogenetic Mechanisms. A Systematic Review

OBJECTIVE

The purpose of this manuscript is to analyze the evidence regarding etiopathogenesis of knee osteochondritis dissecans (OCD) lesions through a systematic review, so to summate the current understanding of the origin and progression of this pathologic articular processes.

DESIGN

A systematic review of the literature was performed on the PubMed and Cochrane databases on October 2017 by 2 independent authors and included all levels of evidence. This included all English language literature, pertaining specifically to etiopathology of knee OCD with exclusions for review articles and expert opinion. Of 965 identified records, 154 full-text articles were assessed for eligibility and 86 studies met the inclusion criteria.

RESULTS

According to these studies, the etiology of OCD can be of a biological or mechanical origin: 40 articles proposed a biological hypothesis, including genetic causes (27), ossification center deficit (12), and endocrine disorders (9); conversely, 52 articles supported a mechanical hypothesis, including injury/overuse (18), tibial spine impingement (5), discoid meniscus (16), and biomechanical alterations (20) as the cause of the onset of OCD. The pathogenic processes were investigated by 36 of these articles, with a focus on subchondral bone fracture and ischemia as the ultimate events leading to OCD.

CONCLUSIONS

Biological and mechanical factors are found to result in subchondral bone remodeling alterations, acting independently or more likely synergically in the progression of knee OCD. The former includes genetic causes, deficit of ossification centers and endocrine disorders; the latter, tibial spine impingement, discoid meniscus, and biomechanical alterations, together with injuries and overuse. The resultant subchondral bone ischemia and/or fracturing appears to determine the onset and progression of OCD.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, level IV.

Juvenile osteochondritis dissecans (JOCD) of the knee: current concepts review

Juvenile osteochondritis dissecans (JOCD) is a joint disorder of the subchondral bone and articular cartilage that affects skeletally immature patients.

The aetiology of JOCD is unknown and the natural history is poorly characterized in part due to inconsistent and largely retrospective literature.

Most OCD in children and adolescents presents as a stable lesion amenable to non-operative treatment or minimally invasive drilling. However, unstable forms can require a more aggressive approach.

This article reviews the most recent literature available and focuses on the pathophysiology, diagnosis and treatment of JOCD of the knee.

Cite this article: EFORT Open Rev 2019;4:201-212. DOI: 10.1302/2058-5241.4.180079

Juvenile osteochondritis dissecans of the knee is a result of failure of the blood supply to growth cartilage and osteochondrosis

OBJECTIVE

Juvenile osteochondritis dissecans (JOCD) is similar to osteochondrosis dissecans (OCD) in animals, which is the result of failure of the cartilage canal blood supply, ischemic chondronecrosis and delayed ossification, or osteochondrosis. The aim of the current study was to determine if osteochondrosis lesions occur at predilection sites for JOCD in children.

METHOD

Computed tomographic (CT) scans of 23 knees (13 right, 10 left) from 13 children (9 male, 4 female; 1 month to 11 years old) were evaluated for lesions consisting of focal, sharply demarcated, uniformly hypodense defects in the ossification front. Histological validation was performed in 11 lesions from eight femurs.

RESULTS

Thirty-two lesions consisting of focal, uniformly hypodense defects in the ossification front were identified in the CT scans of 14 human femurs (7 left, 7 right; male, 7-11 years old). Defects corresponded to areas of ischemic chondronecrosis in sections from all 11 histologically validated lesions. Intra-cartilaginous secondary responses comprising proliferation of adjacent chondrocytes and vessels were detected in six and two lesions, whereas intra-osseous responses including accumulation of chondroclasts and formation of granulation tissue occurred in 10 and six lesions, respectively. One CT cyst-like lesion contained both a pseudocyst and a true cyst in histological sections.

CONCLUSION

Changes identical to osteochondrosis in animals were detected at predilection sites for JOCD in children, and confirmed to represent failure of the cartilage canal blood supply and ischemic chondronecrosis in histological sections.

Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome

BACKGROUND

Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a posteromedial lesion of OLT (medial OLT), the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial lesion and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT.

METHODS

Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. On the coronal images of MRI, the attachment of deltoid ligament was measured. The continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings.

RESULTS

Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet.

CONCLUSIONS

The location of the deep deltoid ligament attachment to the medial OLT was more proximal and there was the possibility of these anatomic feature might contribute to the pathogenesis of medial OLT.

Osteochondritis dissecans of the knee

Osteochondritis dissecans (OCD) of the knee is an idiopathic, focal, subchondral-bone abnormality that can cause instability or detachment of a bone fragment and overlying articular cartilage, with subsequent progression to osteoarthritis. The diagnosis is usually made during adolescence. Mechanical factors play a major role in the pathophysiology of OCD. When the radiographic diagnosis is made early in a patient with open physes, healing can often be obtained simply by restricting sports activities. The degree of lesion instability can be assessed by magnetic resonance imaging. When the lesion remains unstable and the pain persists despite a period of rest, surgery is indicated. Arthroscopic exploration is always the first step. Drilling of the lesion produces excellent outcomes if the lesion is stable. Unstable lesions require fixation and, in some cases, bone grafting. Defects must be filled, depending on their surface area. Although many surgical techniques are available, the therapeutic indications are now standardized.

Non-linear optical microscopy of cartilage canals in the distal femur of young pigs may reveal the cause of articular osteochondrosis

Background

Articular osteochondrosis is a common cause of leg weakness in pigs and is defined as a focal delay in the endochondral ossification of the epiphysis. The first demonstrated steps in the pathogenesis consist of loss of blood supply and subsequent chondronecrosis in the epiphyseal growth cartilage. Blood vessels in cartilage are located in cartilage canals and become incorporated into the secondary ossification centre during growth. It has been hypothesized that vascular failure occurs during this incorporation process, but it is not known what predisposes a canal to fail. To obtain new information that may reveal the cause of vascular failure, the distal femur of 4 pigs aged 82–140 days was sampled and examined by non-linear optical microscopy. This novel technique was used for its ability to reveal information about collagen by second harmonic generation and cellular morphology by two-photon-excited fluorescence in thick sections without staining. The aims were to identify morphological variations between cartilage canal segments and to examine if failed cartilage canals could be followed back to the location where the blood supply ceased.

Results

The cartilage canals were shown to vary in their content of collagen fibres (112/412 segments), and the second harmonic and fluorescence signals indicated a variation in the bundling of collagen fibrils (245/412 segments) and in the calcification (30/412 segments) of the adjacent cartilage matrix. Failed cartilage canals associated with chondronecrosis were shown to enter the epiphyseal growth cartilage from not only the secondary ossification centre, but also the attachment site of the caudal cruciate ligament.

Conclusion

The variations between cartilage canal segments could potentially explain why the blood supply fails at the osteochondral junction in only a subset of the canals. Proteins linked to these variations should be examined in future genomic studies. Although incorporation can still be a major cause, it could not account for all cases of vascular failure. The role of the caudal cruciate ligament in the cause of osteochondrosis should therefore be investigated further.