Osteochondritis Dissecans: Etiology, Pathology, and Imaging with a Special Focus on the Knee Joint

Treatment of osteochondritis dissecans of the patella in adolescents with nanofractured autologous matrix-induced chondrogenesis (NAMIC): A report of five cases

PURPOSE

Osteochondritis dissecans (OCD) of the patella is a very rare affliction. The aim of this case series is to evaluate the effectiveness of the Nanofractured Autologous Matrix-Induced Chondrogenesis (NAMIC) technique for the treatment of OCD in young adults.

METHODS

Five consecutive patients with patellar osteochondral lesions treated with NAMIC were prospectively studied. There were 4 males and 1 female with a mean age of 15.2 years, ranging from 12 to 18 years. Clinically, they presented pain when going up and down stairs or squatting, effusion, swelling and functional limitation. The International Cartilage Repair Society (ICRS) grade was III in 4 patients and IV in 1 patient. Patients were functionally evaluated with the Lysholm knee score, the Tegner Activity Score (TAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiologically using the Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) score.

RESULTS

All the scores significantly improved two years after surgery with respect to pre-operative values (Lysholm score from 63.8 ± 3.9 before surgery to 91 ± 3.2 at 2 years; Tegner activity score from 3.6 ± 0.5 to 8.2 ± 0.8 and the KOOS score from 45.2 ± 2.6 to 91.2 ± 2.4). Both the X-rays and the Magnetic Resonance Imaging (MRI) showed good joint regularity with an average MOCART of 80 ± 7.1/100.

CONCLUSIONS

Treatment of juvenile patellar osteochondritis dissecans with the NAMIC technique seems to be a reliable technique in the short term to restore the patella joint surface and obtain good functional results.

The Link between Aggrecan and Familial Osteochondritis Dissecans

Osteochondritis dissecans (OCD) is a chronic disease of the articular cartilage characterized by focal lesions of subchondral bone and overlaying cartilage. Through the growing number of reports describing the high prevalence of OCD in some families, the subcategory termed familial OCD (FOCD) was established. With the development of genetic approaches such as genome-wide association studies and sequencing, aggrecan (ACAN) has been identified as one of the genes of interest associated with FOCD. Aggrecan is a crucial protein for the preservation and function of cartilage. However, due to FOCD being characterized relatively recently, there is a paucity of literature on the subject. The purpose of this review is to explore the relationship between ACAN mutations and familial OCD as well as to explore current treatment options and avenues for future research. In vitro and animal studies have shown the importance of ACAN in the preservation of cartilage. However, the only human ACAN mutation related to OCD ever identified is a V2303M mutation in the G3 domain. Multiple treatments have been superficially explored, and some options such as growth hormone (GH) and gonadotrophin-releasing hormone agonists (GnRHa) show potential. Thus, further research on FOCD in needed to identify other ACAN mutations and determine optimal treatment modalities for this patient population.

Multiple Osteochondritis Dissecans in Multiple Joints

Background

Osteochondritis dissecans (OCD) rarely occurs in multiple joints. Furthermore, the existence of left-right asymmetric OCDs in different joints of the contralateral side of the body and lesions occurring with a temporal difference is rare. Here, we report a rare case with multiple OCDs sequentially detected in various joints. Case Presentation. The 15-year-old male patient was referred to our hospital for an OCD in the medial femoral condyle of the left knee. He had a history of an OCD in his right elbow, and his father had a history of surgically treated OCDs in both knees. One year and five months after, surgery was performed to the lesion in his left medial femoral condyle, a new OCD lesion occurred in the femoral trochlea of the same knee, which was again treated surgically. Five months after the second surgery, the patient returned with pain in the right knee, and an OCD on the right femoral trochlea was detected by an MRI scan. This lesion remained stable without any further restriction in physical activities for 17 months until detachment occurred and was again treated surgically.

Conclusion

In cases with history and a family history of multiple OCDs, in particular, with a short stature, an MRI scan should be performed for the symptomatic joint to detect and treat the lesion before progression.

Bioabsorbable Unsintered Hydroxyapatite/Poly-l-Lactic Acid Pin Fixation of Osteochondritis Dissecans in Adolescents: Initial Experiences

BACKGROUND

This study sought to retrospectively evaluate the clinical and magnetic resonance imaging (MRI) outcomes of u-HA/PLLA pin (u-HA/PLLA: hydroxyapatite/poly-L-lactic acid) pin fixation of unstable osteochondritis dissecans (OCD) lesions of the knee.

METHODS

Seven adolescent patients (four females and three males) with arthroscopically unstable OCD lesions of the knee were included. The mean age at diagnosis was 13.1 years. Clinical results were evaluated preoperatively and during follow-up using the Ogilvie-Harris score (0 - 15 points). MRI scans were performed preoperatively and during follow-up, with results evaluated using the Dipaola classification (grades 1 - 4). Mean follow-up time was 29 months.

RESULTS

The median Ogilvie-Harris score improved from 13 points (range: 10 - 14 points) to 15 points (range: 13 - 15 points). Separately, the median Dipaola score improved from 3 points (range: 2 - 4 points) to 1 point (range: 1 - 4 points). No complications such as infection, synovitis, or intra-articular adhesion were observed.

CONCLUSIONS

Initial experiences using bioabsorbable u-HA/PLLA pins for the refixation of unstable OCD lesions in adolescents in the knee are promising, and MRI provides excellent monitoring of healing.

Open Treatment for Unstable Osteochondritis Dissecans of the Knee: Autologous Bone Grafting and Bioabsorbable Fixation

Osteochondritis dissecans is a common osteochondral abnormality affecting the knee. In unstable lesions, the underlying bone can be significantly abnormal and necessitate treatment. Although many techniques exist, we favor an open surgical approach to ensure that the bone is properly managed. Autologous bone graft can easily be obtained locally and used to restore the bony architecture. The subsequent use of bioabsorbable implants provides a robust means of fixation that allows for single-stage surgery. This Technical Note describes a straightforward but reliable approach to a challenging pathology.

Osteochondral autograft transplantation versus autologous bone-cartilage paste grafting for the treatment of knee osteochondritis dissecans

PURPOSE

To compare the results of two groups of patients affected by osteochondritis dissecans (OCD) of the knee and treated with either osteochondral autologous transplantation (OAT) or bone-cartilage paste grafting (PG).

METHODS

A total of 27 patients affected by OCD lesions of the femoral condyles were included: 15 treated with OAT, 12 with PG, with comparable baseline characteristics (mean age 22.4 ± 7.2 vs. 24.2 ± 8.5 p = n.s., mean defect size 2.2 ± 1 cm² vs 2.6 ± 1 cm² p = n.s.). Patients were evaluated pre-operatively and at 24 and 84 months post-operatively with the International Knee Documentation Committee (IKDC) subjective and objective scores. Sport activity level was evaluated with the Tegner activity score. Adverse events and failures were also recorded.

RESULTS

The IKDC subjective score improved significantly in both groups. At 24 months, a significant improvement from 53.4 ± 9.1 to 80.8 ± 12.9 (p = 0.005) was obtained in the OAT group and from 44.6 ± 11.0 to 71.4 ± 25.3 in the PG group (p = 0.008). A further statistically significant increase was observed at 84 months in both groups. No significant differences were found between OAT and PG at both follow-ups. One OAT patient required post-operative knee mobilization under narcosis and two complained of donor site symptoms. More failures were documented in the PG vs OAT group (25% vs 0%; p = 0.043).

CONCLUSION

Both PG and OAT provided overall satisfactory results up to 84 months follow-up. However, while PG presents the advantages of a less invasive approach with lower adverse events, the higher failure rate of PG should be considered when choosing between these two surgical treatment options for restoration of the articular surface in patients affected by knee OCD.

Perspectives on Synthetic Materials to Guide Tissue Regeneration for Osteochondral Defect Repair

Regenerative engineering holds the potential to treat clinically pervasive osteochondral defects (OCDs). In a synthetic materials-guided approach, the scaffold's chemical and physical properties alone instruct cellular behavior in order to effect regeneration, referred to herein as "instructive" properties. While this alleviates the costs and off-target risks associated with exogenous growth factors, the scaffold must be potently instructive to achieve tissue growth. Moreover, toward achieving functionality, such a scaffold should also recapitulate the spatial complexity of the osteochondral tissues. Thus, in addition to the regeneration of the articular cartilage and underlying cancellous bone, the complex osteochondral interface, composed of calcified cartilage and subchondral bone, should also be restored. In this Perspective, we highlight recent synthetic-based, instructive osteochondral scaffolds that have leveraged new material chemistries as well as innovative fabrication strategies. In particular, scaffolds with spatially complex chemical and morphological features have been prepared with electrospinning, solvent-casting-particulate-leaching, freeze-drying, and additive manufacturing. While few synthetic scaffolds have advanced to clinical studies to treat OCDs, these recent efforts point to the promising use of the chemical and physical properties of synthetic materials for regeneration of osteochondral tissues.

Osteochondritis dissecans (OCD) in Horses - Molecular Background of its Pathogenesis and Perspectives for Progenitor Stem Cell Therapy

Osteochondrosis (osteochondrosis dissecans; OCD) is a disease syndrome of growing cartilage related to different clinical entities such as epiphysitis, subchondral cysts and angular carpal deformities, which occurs in growing animals of all species, including horses. Nowadays, these disorders are affecting increasing numbers of young horses worldwide. As a complex multifactorial disease, OCD is initiated when failure in cartilage canals because of existing ischemia, chondrocyte biogenesis impairment as well as biochemical and genetic disruptions occur. Recently, particular attention have been accorded to the definition of possible relations between OCD and some metabolic disorders; in this way, implication of mitochondrial dysfunctions, endoplasmic reticulum disruptions, oxidative stress or endocrinological affections are among the most considered axes for future researches. As one of the most frequent cause of impaired orthopaedic potential, which may result in a sharp decrease in athletic performances of the affected animals, and lead to the occurrence of complications such as joint fragility and laminitis, OCD remains as one of the primary causes of considerable economic losses in all sections of the equine industry. It would therefore be important to provide more information on the exact pathophysiological mechanism(s) underlying early OC(D) lesions, in order to implement innovative strategies involving the use of progenitor stem cells, which are considered nowadays as a promising approach to regenerative medicine, with the potential to treat numerous orthopaedic disorders, including osteo-degenerative diseases, for prevention and reduction of incidence of the disease, not only in horses, but also in human medicine, as the equine model is already widely accepted by the scientific community and approved by the FDA, for the research and application of cellular therapies in the treatment of human conditions.

A case report of osteochondritis dissecans of the first metatarsophalangeal joint treated with autologous cancellous bone and chondral flap reconstruction

Although osteochondritis dissecans (OD) is well-described in the bibliography, cases of OD in the 1st metatarsophalangeal joint (MTP) are rare clinical situations. We present a 25-year-old male who presented to our department for big toe pain on the left side. Clinical and radiological examination showed the typical findings of OD lesion on the 1st metatarsal head (MH), establishing the diagnosis of OD. Intraoperatively the articular cartilage of the partially detached part of the MH was intact and under it, an empty cavity with a big defect was obvious. Autogenous cancellous bone transplantation from the metatarsal metaphysis, reattachment of the cartilage surface as a chondral flap and edge sealing with fibrin glue was our treatment of choice. OD of the 1st MH should be included in the differential diagnosis of big toe pain, as early diagnosis and treatment are crucial to prevent future osteoarthritis of the 1st MTP.

Three-Dimensional Quantitative Magnetic Resonance Imaging of Epiphyseal Cartilage Vascularity Using Vessel Image Features: New Insights into Juvenile Osteochondritis Dissecans

We introduce a quantitative measure of epiphyseal cartilage vascularity and examine vessel networks during human skeletal maturation. Understanding early morphological changes in the distal femoral condyle is expected to provide information on the pathogenesis of developmental diseases such as juvenile osteochondritis dissecans.

Methods

Twenty-two cadaveric knees from donors ranging from 1 month to 10 years of age were included in the study. Images of bone, cartilage, and vascularity were acquired simultaneously with a 3-dimensional gradient-recalled-echo magnetic resonance imaging (MRI) sequence. The secondary ossification center volume and total epiphysis cartilage volume ratio and articular-epiphyseal cartilage complex and epiphyseal cartilage widths were measured. Epiphyseal cartilage vascularity was visualized for 9 data sets with quantitative susceptibility mapping and vessel filtering, resulting in 3-dimensional data to inform vessel network segmentation and to calculate vascular density.

Results

Three distinct, non-anastomosing vascular networks (2 peripheral and 1 central) supply the distal femoral epiphyseal cartilage. The central network begins regression as early as 3 months and is absent by 4 years. From 1 month to 3 years, the ratio of central to peripheral vascular area density decreased from 1.0 to 0.5, and the ratio of central to peripheral vascular skeletal density decreased from 0.9 to 0.6. A narrow, peripheral vascular rim was present at 8 years but had disappeared by 10 years. The secondary ossification center progressively acquires the shape of the articular-epiphyseal cartilage complex by 8 years of age, and the central areas of the medial and lateral femoral condyles are the last to ossify.

Conclusions

Using cadaveric pediatric knees, we provide quantitative, 3-dimensional measures of epiphyseal cartilage vascular regression during skeletal development using vessel image features. Central areas with both early vascular regression and delayed ossification correspond to predilection sites of juvenile osteochondritis dissecans in this limited case series. Our findings highlight specific vascular vulnerabilities that may lead to improved understanding of the pathogenesis and better-informed clinical management decisions in developmental skeletal diseases.

Clinical Relevance

This paradigm shift in understanding of juvenile osteochondritis dissecans etiology and disease progression may critically impact future patient management. Our findings highlight specific vascular vulnerabilities during skeletal maturation in a group of active young patients seen primarily by orthopaedic surgeons and sports medicine professionals.

Internal Fixation of Osteochondritis Dissecans of the Knee Leads to Good Long-Term Outcomes and High Degree of Healing without Differences between Fixation Devices

The aim of the present study is to describe results at long-term follow-up of internal fixation of unstable Osteochondritis Dissecans (OCD) achieved with three different fixation devices in skeletally mature knees. A retrospective cohort study was performed at 5 to 19 years follow-up. Patient-reported questionnaires were collected at the final follow-up. Postoperative X-rays and MRIs were evaluated for healing of the lesion and articular degeneration. An arthroscopic second look was performed in 74.3% of the cases. Failures were reported as reintervention to address the osteochondral lesion or poor functional outcomes at the last follow-up. A total of 39 subjects with a median follow-up of 10.7 years were included. Herbert screws were used in 51.2% of the cases, bioabsorbable nails in 25.7% of the cases and cannulated screws in 23.1% of the cases. No differences were observed in terms of the clinical score (International Knee Documentation Committee (IKDC) p = 0.211; Lysholm p = 0.197), radiographic union (p = 0.102) or radiographic degeneration (p = 0.238) between the three different fixation devices. Arthroscopic second look found complete stability of the lesions in all 29 cases evaluated. The mean postoperative Lysholm score was 83 (range = 33-100) and IKDC score was 79 (range = 39-100). Radiographic union was seen in 74% of the cases. Lack of radiographic union was correlated with worst functional scores. A failure rate of 20.5% was found: four reinterventions were performed, and four patients had poor scores at last follow up. This study shows that internal fixation of condylar OCD in skeletally mature patients provides good long-term clinical results and a high degree of healing regardless of the dimensions of the lesion and type of fixation.

Utility of Bioabsorbable Fixation of Osteochondral Lesions in the Adolescent Knee: Outcomes Analysis With Minimum 2-Year Follow-up

Background:

Osteochondral lesions (OCLs) of the knee, whether occurring secondary to osteochondritis dissecans or a traumatic osteochondral fracture, are commonly encountered in the pediatric and adolescent population. Given the potential for healing in this population, coupled with adequate surgical reduction and stability of OCL fixation, an opportunity exists to avoid a major restorative procedure and the associated substantial costs and potential morbidity.

Purpose:

To analyze the outcomes of bioabsorbable fixation of OCLs in the adolescent knee at a minimum of 2 years.

Study Design:

Case series; Level of evidence, 4.

Methods:

An institutional review board–approved retrospective review was performed of patients younger than 18 years who underwent bioabsorbable fixation of an OCL of the knee with a minimum 2-year follow-up. Patient demographics, operative details, and postoperative clinical findings were detailed and recorded. All cases were performed by a single surgeon.

Results:

There were 38 patients treated surgically for an OCL between 2009 and 2016. Of these, 38 patients (mean age, 14.7 years) were evaluated at a mean of 59 months. OCL fixation consisted of a mean of 1.4 bioabsorbable screws and 1.5 darts. At final follow-up, mean pre- and postoperative Tegner scores were 6.6 and 6.4, respectively, while Lysholm and Pediatric International Knee Documentation Committee scores were 89.8 and 88.1, respectively. A total of 6 patients underwent secondary procedures postoperatively. One patient required a secondary procedure related to OCL fixation, which was secondary to a proud implant. The other secondary procedures included second-look arthroscopic surgery for pain after an injury postoperatively, planned anterior cruciate ligament reconstruction, staged medial patellofemoral ligament reconstruction, and manipulation under anesthesia for arthrofibrosis (n = 2). None of the 32 patients required a revision cartilage procedure at the time of final follow-up.

Conclusion:

The use of bioabsorbable implants in the adolescent knee appears to be a safe and efficacious treatment with good functional outcomes at long-term follow-up and a low revision rate. Additional long-term multisurgeon and multicenter trials with a larger cohort are needed to further elucidate the role of bioabsorbable fixation of an OCL in the adolescent knee.

[Pathophysiology of aseptic femoral head necrosis: Pathogenesis and histopathological differential diagnosis]

BACKGROUND

Aseptic osteonecrosis is characterized by a complete death of the tissue (necrosis), more specifically, an ischemic necrosis of the lamellar bone tissue. The denotation aseptic refers to causal pathogenesis; therefore, it is not a matter of an infectious, septic-induced bone necrosis as in the case of acute infectious osteomyelitis. Formal pathogenesis leads to either (1) a hypoperfusion of the lamellar bone in the sense of an ischemic necrosis or (2) to directly induced damage of osteocytes and osteoblasts, which causes aseptic osteonecrosis.

CAUSE

The causes of hypoperfusion/ischemia are manifold and entail vascular malformations, coagulopathies, haemoglobinopathies, thrombotic embolisms, myeloproliferative illnesses, air embolisms, decompression-caused illnesses, macro as well as micro traumata and, finally, vasculitis with necrosis, which complete the vascular-induced spectrum. Direct toxic damage to the osteocytes and osteoblasts is primarily caused by alcohol abuse, medical drug therapies (i. e. chemotherapeutic substances or cortisone) and disorders of the lipid embolism. Contemporary molecular and cellular models of pathogenesis assume a so-called dysbalance of the catabolic and anabolic osseous metabolism in osteocytes and osteoblasts. The RANKL-RANK system, the ROS system and PPAR-gamma signal transduction are involved in the molecular pathogenesis.

DIFFERENTIAL DIAGNOSIS

The most relevant histopathologic differential diagnosis entails the complete spectrum of focal osseous changes among which osteonecrosis can occur to a diverse extent: infectious osteomyelitis, chronic immunologic induced osteomyelitis, pseudoarthrosis, infected pseudoarthrosis, bone fractures and malignant metastatic intraosseous diseases and non-metastatic intraosseous malignant diseases.

Stress Fracture of the Ossification Center of the Scaphoid in a Skeletally Immature Gymnast

An eleven-year-old male gymnast felt right wrist pain when performing handstands on the floor without any major traumas. Displaced scaphoid fracture was observed on the anteroposterior view of the radiograph. Both on the T1-weighted image from magnetic resonance imaging (MRI) and on the short TI inversion recovery (STIR) image from MRI, low intensity was detected at the middle of the ossification center of the scaphoid and the physis and the articular cartilage covering the scaphoid bone were preserved without any injury. The patient was diagnosed with stress fracture of the ossification center of the scaphoid and successfully treated conservatively.

Cartilage and Bone Serum Biomarkers as Novel Tools for Monitoring Knee Osteochondritis Dissecans Treated with Osteochondral Scaffold

Knee osteochondritis dissecans (OCD) is a focal disease of the joint characterized by modifications of bone and cartilage tissues. Biomimetic osteochondral scaffolds are used to restore these tissues. The aim of this prognostic prospective cohort study was to evaluate serum biomarkers of cartilage (fragments or propeptide of type II collagen: CTXII, C2C, and CPII) and bone (tartrate-resistant acid phosphatase (TRAP) 5b and osteocalcin (OC)) turnover during follow-up of patients treated with an osteochondral scaffold, to identify which were related to healing outcome and clinical score. We found that cartilage (CPII) and bone (OC) synthetic biomarkers were significantly increased during the first-year follow-up, while the respective degradative markers (CTXII, C2C, and TRAP5b) were not modulated. Only CTXII/CPII and C2C/CPII cartilage ratios were significantly modulated, evidencing a higher remodeling of cartilage compared to bone tissue. Cartilage and bone single biomarkers or ratios at one-year follow-up showed values close to or similar to those of healthy subjects. International Knee Documentation Committee (IKDC) score significantly increased from T0 to T2, while the Tegner score did not. Taking into consideration an IKDC score > 70 as clinical success, we found that all OCD cases with both CPII (> 300 pg/ml) and C2C/CPII (<0.35) presented IKDC scores of clinical success. OCD patients treated with an osteochondral scaffold showed an improvement at one-year follow-up, evidenced by both clinical and serum cartilage biomarkers. These data confirmed that cartilage and bone remodeling took place and showed that systemic biomarkers represent a sensitive tool for monitoring OCD patients during the follow-up.

Clinical and Biological Signature of Osteochondritis Dissecans in a Cross-Sectional Study

The healing potential of knee osteochondritis dissecans (OCD) focal lesions is not well defined. We performed a cross-sectional study correlating local and systemic biological characteristics with the patients' characteristics. We evaluated both local tissue markers (CD34, CD146, CD166, and tartrate-resistant acid phosphatase (TRAP)) and systemic serum biomarkers (fragments or propeptide of type II collagen: C2C, CTX-II, CPII, and TRAP5b) on histologically scored osteochondral fragments or serum from OCD patients. These biological features were associated with the patients' characteristics (IKDC subjective score, age, and body mass index (BMI)). Histological cartilage tissue score correlated with patients' IKDC and C2C and CPII biomarkers. CPII correlated also with histological bone tissue score. The percentage of CD146 positive cells in cartilage and CD34 positive cells in bone highly correlated with the patient's age and BMI, respectively. The percentage of TRAP in bone was directly correlated with both IKDC and age. Multivariate statistical analysis evidenced that only four parameters significantly predicted IKDC. In conclusion, a complete picture of OCD knee characteristics, defined by local and systemic markers of cartilage and bone remodeling, together with the patients' characteristics, might help to better understand the healing potential of each patient and to target and improve current OCD treatments.

PATELLOFEMORAL CHONDRAL DEFECT IN A PREADOLESCENT SKIER: A CASE REPORT IN EARLY SPORT SPECIALIZATION

BACKGROUND AND PURPOSE

Early sport specialization (ESS) refers to intense training year round in a specific sport starting at a young age with no or limited participation in other sports. This approach to training is highly controversial; recent literature suggests that this type of specialized training could be a contributing source to overuse injuries in youth athletes. The purpose of this case report was to describe a patellofemoral articular cartilage defect of the knee in a preadolescent skier due to overuse and repetitive microtrauma as a result of ESS.

STUDY DESIGN

Case Report.

CASE DESCRIPTION

A healthy 11-year-old male competitive alpine skier presented with recurrent swelling of his right knee and persistent anterior knee pain while skiing without evidence of any specific history of injury or traumatic event. The patient failed a conservative treatment regimen including rest and formal physical therapy focused on generalized knee strengthening. Magnetic resonance imaging was ordered and revealed an articular cartilage defect of the medial patellar facet. The patient was treated with an arthroscopic debridement of his articular cartilage defect.

OUTCOME

At 12 weeks postoperatively, the patient presented with a normalized gait pattern, no evidence of knee effusion, full knee range of motion and patellar mobility symmetric to his contralateral limb, and no patellar crepitation or painful palpation on physical exam. The patient was released to begin return to sport progression at 12 weeks, and was cleared for full activities/returned to competitive skiing at 15 weeks postoperatively. At 16 weeks postoperatively, he won an international alpine ski race in Europe for his age group.

DISCUSSION

Cartilage injuries and osteochondral defects are very common in adolescent athletes and often go undiagnosed. Allied healthcare professionals must be educated on the known causes of recurrent knee effusions and how early sport specialization may result in overuse injuries to knee joint cartilage.

LEVEL OF EVIDENCE

4.