Osteochondritis dissecans of the knee

Bone marrow edema of the knee: a narrative review

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse.

Clinical Outcomes and Return-to-Sport Rates following Fragment Fixation Using Hydroxyapatite/Poly-L-Lactate Acid Threaded Pins for Knee Osteochondritis Dissecans: A Case Series

Osteochondritis dissecans (OCD) of the knee is an uncommon injury in young active patients. There is currently a lack of knowledge regarding clinical outcomes and return-to-sport rates after fragment fixation surgery using hydroxy appetite poly-L-lactic acid (HA/PLLA) threaded pins for knee OCD among athletes. Our purpose was to investigate the clinical outcomes and return-to-sport rates following osteochondral fragment fixation using HA/PLLA pins for the treatment of knee OCD lesions among athletes. A total of 45 patients were retrospectively reviewed. In total, 31 patients were excluded, and 14 patients were included. Pre- and postoperative patient-reported outcome scores (PROSs), including the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Scale (KOOS), were compared. In addition, patients were categorized into four groups according to postoperative sports status: higher, same, lower than preinjury, or unable to return to sports. The mean age was 14.4 years (SD 1.67). All patients were male. All PROSs significantly improved at 6, 12, and 24 months postsurgery compared to presurgery. 50% of the patients returned to sports at the same or higher level after surgery. Fragment fixation using HA/PLLA pins leads to favorable clinical outcome scores and high return-to-sport rates in the treatment of athletes with knee OCD.

Bioabsorbable Screw Fixation Provides Good Results With Low Failure Rates at Mid-term Follow-up of Stable Osteochondritis Dissecans Lesions That Do Not Improve With Initial Conservative Treatment

Purpose

To evaluate the clinical and radiographic outcomes of patients who have undergone bioabsorbable screw fixation for intact, stable grade I and II osteochondritis dissecans (OCD) lesions for which at least 6 months of conservative management has failed.

Methods

A retrospective review of prospectively collected data from a single institution was performed to identify patients who underwent internal fixation of stable grade I and II OCD lesions (according to the Guhl classification) between January 2010 and January 2020. Patients were included regardless of the presence of concomitant procedures. The inclusion criteria consisted of (1) primary surgery, (2) failure of at least 6 months of conservative management, (3) the use of a bioabsorbable screw (or screws), and (4) minimum 2-year clinical follow-up. Radiographs were obtained at a minimum of 1 year postoperatively. Patient demographic characteristics, clinical patient-reported outcomes, complications, and failure rates were noted.

Results

Twenty-four knees among 23 patients (96% follow-up) were analyzed and followed up for 6.36 ± 3.42 years (range, 2.0-12.7 years). Patients showed statistically significant postoperative improvements in all patient-reported outcomes including the Lysholm score, International Knee Documentation Committee score, and Knee Injury and Osteoarthritis Outcome Score subscales (P < .05). In 3 knees (12%), a reoperation was required due to failure at an average of 3.64 years after the index procedure. No specific complications were attributed to the use of bioabsorbable screws. Patients in whom primary surgical treatment failed did not differ in demographic characteristics, arthroscopic findings, or surgical treatment from those who had successful treatment.

Conclusions

Internal fixation of stable grade I and II OCD lesions with bioabsorbable screws produces reliable results with a 12% rate of failure in appropriately indicated patients in whom at least 6 months of conservative management has failed. Clinical outcomes improved significantly during the mid-term follow-up period.

Level of Evidence

Level IV, therapeutic case series.

Efficacy of the pridie drilling technique in knee osteochondritis dissecans among children and young adults: follow-up of 41 cases

PURPOSE

This study aims to examine whether Pridie drilling, a form of bone marrow stimulation, can expedite the healing process and enable a faster return to sports activity in patients with knee Osteochondritis dissecans (OCD). The primary objective is to assess the effectiveness of Pridie drilling in stable OCD lesions that do not respond to non-operative treatment, by evaluating the absence of painful symptoms 6 months after the procedure. Secondary objectives include evaluating radiographic reconstruction 6 months post-surgery and determining the time it takes to resume sports participation.

MATERIALS AND METHODS

This single-center retrospective study included all cases of stable OCD in the knee that underwent anterograde chondral drilling between 2008 and 2020. Diagnosis of OCD was established using knee radiographs, and the surgical technique involved multiple multidirectional subchondral drilling. Treatment efficacy was defined by the absence of painful symptoms for 6 months postoperatively.

RESULTS

A total of 41 knees were included in the study, and no complications were observed before or after surgery. At 6 months postoperatively, 32 knees (78%) showed complete resolution of symptoms. Complete radiographic reconstruction was observed in 66% of cases. Asymptomatic patients at 6 months returned to sports activity of similar intensity to that practiced previously in an average time of 7.9 months; while, patients who were symptomatic at 6 months returned in an average time of 16.5 months.

CONCLUSION

This study provides evidence supporting the short-term efficacy of anterograde chondral drilling in stable lesion of OCD in children and adolescents after failed functional treatment.

LEVEL OF EVIDENCE

Level III (retrospective cohort study).

Osteochondritis Dissecans of the Knee Associated With Mechanical Overload

BACKGROUND

Osteochondritis dissecans (OCD) of the knee is a rare but potentially incapacitating disorder in which subchondral bone detaches, leading to an osteochondral fragment that can become unstable and progress into a loose body. The exact cause is unknown, although several biological and mechanical factors have been described.

PURPOSE

To provide insight into epidemiological data of a large cohort of patients affected by OCD of the knee and to identify potential factors contributing to the cause of this disorder.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 236 patients (259 knees) affected by OCD were included in our Knee Registry (2005-2022) and retrospectively analyzed. Patient characteristics were extracted from the medical records. Location and International Cartilage Regeneration & Joint Preservation Society grade (1-4) of OCD were assessed using magnetic resonance imaging. If available, a full-leg standing radiograph was used to assess alignment. Additionally, a statistical scoring system for instability risk was created.

RESULTS

A total of 263 OCD lesions were identified in 259 knees, 66.2% on the medial femoral condyle (MFC), 26.6% on the lateral femoral condyle (LFC), 3.8% on the trochlea, 2.7% on the patella, and 0.8% on the lateral tibia plateau. Male patients made up 57.6% of the sample, which had a mean age of 21.8 years. A very high percentage of patients (77.1%; n = 182) practiced sports, of whom 67.6% (n = 123) were engaged in high-impact sports. The location of the OCD lesions and the leg alignment (n = 110) were significantly correlated: MFC lesions were associated with more varus than valgus alignment (47.5% vs 11.3%) and patients with LFC lesions had more valgus than varus alignment (46.7% vs 20.0%; P = .002). Based on age, smoking, sports activity, and preceding trauma, a multivariable scoring system (0-11 points) was created. An increased risk of lesion instability was associated with an increased score: 29.0% at 0 points and 97.0% at 11 points.

CONCLUSION

This study provides detailed epidemiological data for 236 patients affected by OCD of the knee. Older age, smoking, inactivity, and preceding trauma were predictive for instability of OCD lesions. There was an association between OCD of the MFC and varus malalignment and between OCD of the LFC and valgus malalignment. This finding, in combination with the high percentage of patients practicing high-impact sports, suggests an important role for mechanical overload in the pathogenesis of OCD.

Evaluation of lesion and overlying articular cartilage in patients with juvenile osteochondritis dissecans of the knee using quantitative diffusion MRI

Current clinical MRI of patients with juvenile osteochondritis dissecans (JOCD) is limited by the low reproducibility of lesion instability evaluation and inability to predict which lesions will heal after nonoperative treatment and which will later require surgery. The aim of this study is to verify the ability of apparent diffusion coefficient (ADC) to detect differences in lesion microstructure between different JOCD stages, treatment groups, and healthy, unaffected contralateral knees. Pediatric patients with JOCD received quantitative diffusion MRI between January 2016 and September 2020 in this prospective research study. A disease stage (I-IV) and stability of each JOCD lesion was evaluated. ADCs were calculated in progeny lesion, interface, parent bone, cartilage overlying lesion, control bone, and control cartilage regions. ADC differences were evaluated using linear mixed models with Bonferroni correction. Evaluated were 30 patients (mean age, 13 years; 21 males), with 40 JOCD-affected and 12 healthy knees. Nine patients received surgical treatment after MRI. Negative Spearman rank correlations were found between ADCs and JOCD stage in the progeny lesion (ρ = -0.572; p < 0.001), interface (ρ = -0.324; p = 0.041), and parent bone (ρ = -0.610; p < 0.001), demonstrating the sensitivity of ADC to microstructural differences in lesions at different JOCD stages. We observed a significant increase in the interface ADCs (p = 0.007) between operative (mean [95% CI] = 1.79 [1.56-2.01] × 10-3  mm2 /s) and nonoperative group (1.27 [0.98-1.57] × 10-3  mm2 /s). Quantitative diffusion MRI detects microstructural differences in lesions at different stages of JOCD progression towards healing and reveals differences between patients assigned for operative versus nonoperative treatment.

Improving Visualization of Osteochondritis Dissecans Using Delay-Multiply-and-Sum Reconstruction

OBJECTIVE

Osteochondritis dissecans (OCD) of the capitellum is a joint defect that is common among adolescent athletes. It is important to diagnose OCD as early as possible, because early-stage OCD lesions have a high rate of spontaneous healing with rest. Medical ultrasound could potentially be used as a screening tool for OCD but is limited by the use of delay-and-sum (DAS) reconstruction. In this study, we tested conventional delay-multiply-and-sum (DMAS) and novel low-pass DMAS reconstruction algorithms for better visualization of OCD lesions.

METHODS

We created phantom and cadaveric OCD models that simulated a range of OCD lesion severities and stabilities. We also imaged an in vivo case of OCD in a patient study. In the reconstructed images, several profiles were taken to measure OCD lesion contrast, cartilage contrast, crack thickness error and bone interface clarity.

RESULTS

In the phantom and cadaveric OCD models, we found that histogram-matched conventional DMAS reconstruction improved lesion contrast by up to 16%, cartilage contrast by 26% and bone interface clarity by 15% on average compared with DAS reconstruction. Histogram-matched low-pass DMAS reconstruction improved lesion contrast by up to 22%, cartilage contrast by 45%, and bone interface clarity by 29% on average compared with DAS reconstruction. In the in vivo case of OCD, we found that histogram-matched conventional and low-pass DMAS reconstruction improved lesion contrast by 22% and 26%, respectively.

CONCLUSION

The application of DMAS reconstruction improved the ability of medical ultrasound to detect OCD lesions of the capitellum when compared with DAS reconstruction.

Long-Term Outcome and Athletic Level following Operative Treatment for Osteochondritis Dissecans of the Knee in Pediatric and Adolescent Patients

Research on the long-term outcomes following surgical therapy for osteochondritis dissecans (OCD) of the knee is scarce. A single-center retrospective cohort study was conducted to investigate surgically treated patients for knee OCD between 1993 and 2007. A total of 37 patients with an average follow-up duration of 14 years (range 8-18) were in the final cohort. IKDC and Lysholm scores were assessed. The duration and types of sport activity were reported. Long-term results were compared with existing midterm data. Knee scores showed a very good outcome with a mean of 91.3 in the IKDC score and 91.7 in the Lysholm score. Compared to midterm outcomes, both IKDC (p = 0.028) and Lysholm scores (p = 0.01) improved on final follow-up. Patients with open physes showed a significantly better Lysholm score compared to patients with closed physes (p = 0.034). Defect localization and size did not influence the outcome, but a defect depth of <0.8 cm² achieved significantly better scores than ≥0.8 cm². Of all surgical interventions, refixation achieved the best outcome. Long-term results significantly improved compared to midterm results with a follow-up of 40 months (p = 0.01). Thirty-six out of 37 patients were physically active, with 56% of sports being knee-straining activities. Long-term results following surgically treated OCD fragments show excellent function and a good athletic level. Patients with open physes potentially have better knee outcomes. Midterm results are sustainable and could improve further in the long term.

Surgical management of osteochondral lesions of the first metatarsal head: A systematic review

BACKGROUND

Treating osteochondral lesions of the first metatarsal head can help reducing pain and preventing end-stage arthritic cartilage degeneration and hallux rigidus. Several surgical techniques have been described, but no clear indications are reported. This systematic review aims to offer an overview of the current surgical treatments for focal osteochondral lesions of the first metatarsal head.

METHODS

The selected articles were examined to extract data about population, surgical technique, and clinical outcomes.

RESULTS

Eleven articles were included. Mean age at surgery was 38,2 years. Osteochondral autograft was the most used technique. After surgery, an improvement was achieved in AOFAS, VAS, and hallux dorsiflexion but not in plantarflexion.

CONCLUSION

There is limited evidence and knowledge regarding the surgical management of the first metatarsal head osteochondral lesions. Various surgical techniques have been proposed, drawn from other districts. Good clinical results have been reported. Further high-level comparative studies are necessary to design an evidence-based treatment algorithm.

Osteochondritis dissecans

Osteochondritis dissecans is a condition characterised by acquired pathological subchondral bone lesions and its incidence is unknown. It has a multifactorial aetiology, with a combination of genetic and acquired risk factors. It commonly presents in adolescents and young adults. Patients have variable presentations, including trauma, insidious onset and pain exacerbated by exercise. The joints primarily affected are the knee, ankle and elbow joint. Early identification is key to treatment and to prevent future osteoarthritis of the joint. This article gives an overview of the presentation, assessment and management of the juvenile form of osteochondritis dissecans.

The "hump" a new arthroscopic phenomenon guiding for reliable therapy of osteochondritis dissecans of variable stability status

INTRODUCTION

Despite 150 years of research, there are currently no reliable morphological characteristics that can be used to differentiate between stable and unstable juvenile osteochondritis dissecans (JOCD) lesions in the knee joint. Arthroscopic probing is still the gold standard. In arthroscopic evaluation, a previously undescribed pattern of a cartilaginous convex elevation ("hump") was identified as a new feature and potential sign of JOCD in transition to instability. The aim of the study was to evaluate the clinical outcomes after surgical intervention (drilling) on the "hump".

MATERIALS AND METHODS

In a retrospective case series of sixteen patients with an arthroscopically detectable "hump", the analysis of clinical function scores (Lysholm, Tegner) and morphological MRI monitoring of radiological healing were performed. The assessment of lesion healing was based on pre- and postoperative MRI examinations. The "hump" was defined as an arthroscopically impressive protrusion of the femoral articular surface with a minimally softened, discolored, but intact cartilage margin that, is not mobile upon in the arthroscopic palpation hook test. The primary therapy of choice was drilling of all "humps".

RESULTS

The "hump" could be detected arthroscopically in 16 of 59 JOCD lesions. Specific MRI correlations with the "hump" or arthroscopic unstable lesions could not be detected. Not all "humps" showed signs of MRI-based healing after the drilling, and in some a dissection of the osteochondral flap occurred within the first postoperative year. As a result, secondary refixation became necessary.

CONCLUSION

In the present study, the "hump" was identified as an important differential diagnostic arthroscopic feature of an arthroscopically primarily stable JOCD lesion, potentially placing the lesion at risk of secondary loosening over time. Therefore, drilling alone may not be appropriate in the event of arthroscopic "hump" discovery, but additional fixation may be required to achieve the healing of the lesion.

LEVEL OF EVIDENCE

III.

Osteochondritis dissecans of the knee in adolescents: How to treat them?

Background

Osteochondritis dissecans is an acquired condition of the joint that affects the articular surface and the subchondral bone. The juvenile form of osteochondritis dissecans presents in those aged 5-16 years with open growth plates. The causes of osteochondritis dissecans are unknown.

Methods

The goals of treatment are to promote healing of the subchondral bone and prevent chondral collapse, subsequent fracture, osteochondral defect formation, and early joint degeneration. Treatment modality is influenced on clinical symptoms, skeletal maturity, as well as the size, stability, and location of the lesion. This article will review the treatment strategies of juvenile form of osteochondritis dissecans of medial femoral condyle and of atypical regions, such as lateral femoral condyle, patellofemoral joint, and tibial plateau.

Level of evidence

level III.

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.

Physeal fusion status and lesion size are more important than patient age for healing of juvenile osteochodritis dessicans lesions of the distal femur

PURPOSE

The purpose of the study was to evaluate the effect of skeletal age and lesion size, location, and grade on the success of nonoperative treatment for juvenile osteochondritis dissecans (OCD). It is hypothesized that skeletal maturity, including a combination of maturation phenotypes, correlates with nonoperative lesion healing.

METHODS

The clinical and radiographic data on 52 patients aged 7-20 years treated for OCD of the distal femur between 2010 and 2019 were retrospectively reviewed. Knee radiographs were assessed for number of lesions present and lesion location, size, and stage. Assessments of skeletal maturation were performed on all antero-posterior knee radiographs using the Roche, Wainer, and Thissen (RWT) method. Patients were categorized as healed if they demonstrated no pain on clinical examination. The relationship between skeletal maturity and nonoperative lesion healing was determined using Spearman rank correlations on available variables.

RESULTS

Neither chronological nor skeletal age was associated with surgical status (Rho = 0.03, n.s., and Rho = 0.13, n.s., respectively) or the healing status of nonoperatively treated OCD lesions (Rho = 0.44, n.s., and Rho = 0.03, n.s., respectively). Epiphyseal fusion status of the distal femoral physis was moderately correlated with nonoperative healing, but was not statistically significant (lateral femoral physis: Rho = 0.43, p = 0.05; medial femoral physis: Rho = 0.43, n.s.). Lesion length correlated with surgical status (Rho = - 0.38, p = 0.009).

CONCLUSION

The extent of fusion of the distal femoral physis (multi-stage grading) may be more strongly correlated with nonoperative healing than other markers of skeletal maturity or chronological age. Clinicians can use this as an additional radiographic sign when considering nonoperative treatment for juvenile OCD lesions in the distal femur. OCD lesion length and physeal fusion status appear to be more important for healing than patient age.

Evaluating Information About Osteochondritis Dissecans Shared Across Social Media Platforms

BACKGROUND

With the rise of social media, patients are using a variety of online resources to gather information about medical conditions and connect with others for support. Osteochondritis dissecans (OCD) occurs most commonly among children and adolescents, necessitating early diagnosis and management. The purpose of this study is to evaluate content on social media about OCD to quantify the reach of information shared and themes of discussion surrounding this condition.

METHODS

A search was performed across Facebook, Instagram, YouTube, and TikTok using the term "osteochondritis dissecans" to identify information shared related to this topic which was then analyzed based on engagement using number of followers, posts, and/or views.

RESULTS

Facebook groups provided a forum for online support and information sharing among patients with OCD and their families. The 4 identified groups had a cumulative following of over 4000 people with posts that shared personal recovery stories, solicited treatment advice, and provided updates on patient progress. Review of related Instagram hashtags revealed over 4500 posts, many of which shared personal accounts of living with OCD. The top 5 most viewed YouTube videos collectively had over 189,000 views and were focused on educational information about OCD, relevant surgical techniques, and pertinent anatomy. The top 3 OCD-related TikTok hashtags had over 4 million total views centered on factual knowledge and sharing changes before and after surgical treatment.

CONCLUSION

Patients with OCD and their families seek information about their condition and treatment on online sources including social media. Although social media provides a supportive community to share and receive advice, the quality of information shared in these groups is a subject for concern. Increasing physician involvement and awareness of the information shared across social media platforms may improve accuracy of information and content available to patients.

CLINICAL RELEVANCE

It is important for physicians treating patients with OCD to be aware of all sources of information and support, including content shared on social media as these platforms allow for the sharing of personal stories, recommendations for treatment, and educational content.

Males and Females Exhibit Comparable Outcomes Following Treatment of Osteochondritis Dissecans Lesions of the Knee: A Systematic Review

PURPOSE

The purpose of this study was to evaluate the impact of patient sex on outcomes after treatment of osteochondritis dissecans (OCD) lesions of the knee through a systematic review of current evidence.

METHODS

This review was conducted according to the PRISMA guidelines using the PubMed, PubMed Central, Embase, Ovid Medline, Cochrane Libraries, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Relevant outcomes included functional (e.g., International Knee Documentation Committee and Subjective Knee Evaluation, Lysholm Knee Score) and clinical outcomes (e.g., symptom/pain resolution, reoperation rates) for males and females after operative or nonoperative treatment of knee OCD lesions.

RESULTS

Ten articles with a total of 691 (73%) males and 260 (27%) females were included. Mean age ranged from 11.3 ± 2.1 years to 34.5 ± 10.3 years, and follow-up ranged from 6 months to 16.3 years. In four studies reporting functional outcomes, no significant differences were found between males and females in any metric assessed (all P > .05). Seven studies reported clinical outcomes after treatment of knee OCD lesions. One study determined males were more likely to have a successful nonoperative outcome than females (OR: 1.85, 95% CI: 1.00-3.40). Another study found males had a lower risk of developing symptomatic knee pain following operative or nonoperative treatment at a mean 14-year follow-up (HR: 0.24; 95% CI: 0.07-0.81). The remaining 5 studies reported statistically comparable clinical outcomes between males and females (all P > .05).

CONCLUSION

The present systematic review found mostly comparable clinical and functional outcomes between males and females following treatment of knee OCD lesions. Despite sex-related differences in the prevalence of these lesions and limited evidence of differences in clinical outcomes, these data suggest that sex does not independently predict outcomes after treatment.

LEVEL OF EVIDENCE

III, systematic review of Level II and III studies.

Classification Systems for Knee Osteochondritis Dissecans: A Systematic Review

OBJECTIVE

Aim of this systematic review was to describe all classification systems for knee osteochondritis dissecans (OCD) lesions, evaluating their accuracy and reliability, as well as their use in the literature on knee OCD.

DESIGN

A systematic review of the literature was performed in July 2021 on PubMed, WebOfScience, and Cochrane Collaboration (library) to describe all published classification systems for knee OCD lesions and quantify the use of these classifications in the literature.

RESULTS

Out of 1,664 records, 30 studies on 33 OCD classifications systems were identified, describing 11 radiographic, 13 MRI, and 9 arthroscopic classifications. The search included 193 clinical studies applying at least one OCD classification, for a total of 7,299 knee OCD cases. Radiographic classifications were applied to 35.8%, MRI to 35.2%, and arthroscopic classifications to 64.2% of the included studies. Among these, in the last two decades, the International Cartilage Repair Society's (ICRS) arthroscopic classification was the most described approach in studies on knee OCD. Overall, there is a lack of data on accuracy and reliability of the available systems.

CONCLUSIONS

Several classifications are available, with ICRS being the most used system over the time period studied. Arthroscopy allows to confirm lesion stability, but noninvasive imaging approaches are the first line to guide patient management. Among these, radiographic classifications are still widely used, despite being partially superseded by MRI, because of its capability to detect the earliest disease stages and to distinguish stable from unstable lesions, and thus to define the most suitable conservative or surgical approach to manage patients affected by knee OCD.

LEVEL OF EVIDENCE

Systematic review, level IV.

Osteochondral Allograft Transplantation of the Lateral Femoral Condyle and Distal Femoral Osteotomy in the Setting of Failed Osteochondritis Dissecans Fixation

Osteochondritis dissecans (OCD) is a pathologic condition, most commonly affecting the knee joint in adolescents and young adults, although pathology can also be found at the elbow and ankle. Lesions to the medial femoral condyle are classically associated with varus alignment, while lesions to the lateral femoral condyle are seen in patients with valgus malalignment. Common risk factors for failed fixation of OCD lesions include unstable lesions to the lateral femoral condyle, screw breakage, older age, and closed physes. The purpose of this technical note is to describe the preoperative planning and step-by-step surgical approach for treatment of failed fixation of an OCD lesion of the posterior aspect of the lateral femoral condyle in young, active patients using an osteochondral allograft, a lateral opening wedge distal femoral osteotomy to correct malalignment, and a tibial tubercle osteotomy to facilitate access to the lesion.

What Do We Currently Know About Patellofemoral Osteochondritis Dissecans?

OBJECTIVE

Knee osteochondritis dissecans (OCD) is a still poorly understood pathological condition of the articular subchondral bone and its overlying cartilage. Patellofemoral involvement accounts for less than 1% of cases; tibial plateau and multifocal involvement is an even rarer instance. The purpose of this study is to review what is currently known about patellofemoral OCD (PF-OCD) and to present an unusual case of PF-OCD which progressed to become multifocal in an adult female patient.

METHODS

A comprehensive literature search was conducted on PubMed/Medline, Cochrane, Embase, Web of Science, and Scopus databases on September 2021 for all levels of evidence and English language. After duplicate removal, 234 papers pertaining to PF-OCD were retrieved. Thirty-nine studies met inclusion criteria and were included in the review. As an example, a unique case of delamination of patellar cartilage consistent with PF-OCD with progressive involvement of trochlea and both tibial plateau in a 35-year-old woman is also presented.

RESULTS

PF-OCD is a rare localization of knee OCD. Two hundred eighty-eight cases have been reported in the literature to date. Mean age at time of diagnosis was 16 years and the location could also be bilateral and multifocal. The etiology is still debated but traumatic, vascular, and hereditary mechanisms are likely. Management mirrors that of classical OCD.

CONCLUSIONS

PF-OCD is an uncommon cause of anterior knee pain but should be considered even when physeal plates are closed. Current available evidence on treatment is of low quality, based on single case reports or small retrospective case series.

Treatment of Juvenile Knee Osteochondritis Dissecans with a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and MRI Results at Mid-Term Follow-up

OBJECTIVE

Osteochondral surgical procedures have been described for the treatment of unfixable osteochondritis dissecans (OCD), but only few of them have been studied for juvenile OCD (JOCD) lesions. A cell-free biomimetic osteochondral scaffold showed positive results in adult patients. The aim of this study was to evaluate the results of this scaffold for the treatment of knee JOCD at mid-term follow-up.

DESIGN

Twenty patients (14 males, 6 females) were included in this study. Mean age was 16.2 ± 1.4 years, average defect size was 3.2 ± 1.8 cm², and mean symptoms duration was 20.2 ± 17.9 months. After the implantation of the osteochondral collagen-hydroxyapatite scaffold (Maioregen, Fin-Ceramica, Faenza, Italy), patients were evaluated preoperatively and prospectively at 1, 2, and at final mean follow-up of 6 years (range 5-7 years) with International Knee Documentation Committee (IKDC) subjective and objective, Tegner, and EuroQol visual analogue scale (VAS) scores. MRI evaluation was performed with the MOCART 2.0 score.

RESULTS

All scores showed a significant improvement. IKDC subjective score went from 50.3 ± 17.4 preoperative score to 75.3 ± 14.6 at 1 year (P = 0.002), 80.8 ± 14.6 at 2 years and 85.0 ± 9.3 at 6 years. The Tegner score improved from the preoperative evaluation of 2.6 ± 1.4 to 5.5 ± 2.0 at 6 years (P < 0.0005), although without reaching the level registered before the onset of symptoms. A longer symptoms duration influenced negatively IKDC subjective and Tegner scores up to 2 years (P = 0.003 and P = 0.002, respectively) but did not affect the final outcome. Lesion size did not affect the final result. The MOCART 2.0 score showed a significant improvement between 1-year and final follow-up, but with persisting subchondral alterations.

CONCLUSIONS

This study demonstrated a clinical improvement stable over time with a high survival rate, although with persisting abnormal MRI findings, especially at subchondral bone level. This procedure can be considered a suitable option for the treatment of young patients affected by knee OCD. Level of evidence. Case series, level IV.

Juvenile Osteochondritis Dissecans of the Knee Joint: Midterm Clinical and MRI Outcomes of Arthroscopic Retrograde Drilling and Internal Fixation with Bioabsorbable Pins

OBJECTIVE

This study aimed to assess the clinical and radiographic outcomes of juvenile patients who suffered from stage II or III osteochondritis dissecans (OCD) of the knee and underwent arthroscopic retrograde drilling and internal fixation with bioabsorbable pins.

DESIGN

Medical and radiological records from patients aged 11 to 16 years, who underwent arthroscopic treatment for OCD lesions of the knee in 2 tertiary hospitals, were retrospectively reviewed. The procedure was indicated by persistent pain and by magnetic resonance imaging (MRI). All patients underwent retrograde drilling and arthroscopic fixation of the lesion with bioabsorbable pins. MRI was conducted at least 1 year postoperative in all patients to evaluate healing. Functional outcomes were evaluated through the Visual Analogue Scale (VAS) for pain, Lysholm, and IKDC (International Knee Documentation Committee) scores.

RESULTS

A total of 40 patients, with an average age of 13.1 years (range = 11-16 years) and an average follow-up of 6.6 years (range = 3-13 years) were reviewed. MRI findings confirmed the healing of the lesion in 36 out of the 40 (90%) patients. In particular, the healing rate was 95% (20/21) and 84% (16/19) for stage II and stage III, respectively. Lysholm, IKDC, and VAS scores revealed a statistically significant improvement (P < 0.05) at final follow-up in comparison to preoperative status. No infection, knee stiffness, or other complication was recorded.

CONCLUSIONS

Retrograde drilling combined with internal fixation with bioabsorbable pins, of stages II and III OCD lesions of the knee provides good to excellent outcomes to juvenile patients, with a high healing rate.

Impaction Bone Grafting for Treatment of Unstable Osteochondritis Dissecans (OCD) Lesions

Although treatment options for unstable and unsalvageable large osteochondral lesions have largely been limited to autologous chondrocyte implantation (ACI) and osteochondral allografts, isolated impaction bone grafting represents a cost-friendly alternative, with predictable outcomes comparable to other options. Furthermore, the procedure can be completed in a single stage on an elective basis. We present our technique for impaction bone grafting of unstable osteochondritis dissecans (OCD) using either cancellous autograft or allograft.

An adult case of spontaneous healing of concurrent osteochondritis dissecans of the lateral femoral condyle after saucerization with meniscal repair for discoid lateral meniscus: A case report

BACKGROUND

The treatment strategy for osteochondritis dissecans (OCD) with discoid lateral meniscus (DLM) in adults remains unclear.

CASE PRESENTATION

A 22-year-old man presented with left knee pain after spraining his knee. Physical examination revealed lateral joint line tenderness and a positive McMurray test. Radiographic imaging showed OCD of the lateral femoral condyle classified as stage 3 on Brückl's classification. Magnetic resonance imaging showed complete DLM with anterocentral shift based on Ahn's classification and an OCD of 11 mm × 8 mm, grade 2 based on Nelson's classification. On computed tomography (CT), a demarcated fragment was observed in the lesion. Based on these findings, saucerization with meniscal repair was performed for unstable DLM. The OCD lesion presented with softening without any fissure and was diagnosed as grade 1. No surgical procedure was added. One year after surgery, the union of the fragment was confirmed on radiograph and CT. At the final follow-up five years after surgery, the Lysholm score had improved from 58 to 100 points.

CONCLUSIONS

We experienced an adult case of stable OCD with concurrent DLM that achieved spontaneous healing after undergoing reshaping surgery for DLM, mimicking normal meniscal morphology, without additional treatment for the stable OCD lesion.

The incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knees: a systematic review and meta-analysis

PURPOSE

The current systematic review and meta-analysis aim to pool together the incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knee.

METHODS

The systematic review was conducted according to PRISMA guidelines. A search was conducted using PubMed and Cochrane Library with the keywords being "knee" and "osteochondritis dissecans" or "osteochondral lesion". All original human studies that reported the incidence or risk factors of osteoarthritis following osteochondritis dissecans of the knee were included.

RESULTS

Nine studies with 496 patients were included. The incidence of osteoarthritis following osteochondritis dissecans is 0.39 (95% CI 0.19-0.59). Patients with a body mass index greater than 25 kg/m² had a significantly increased risk of osteoarthritis. Fragment excision had an increased relative risk of 1.89 (95% CI 1.19-3.01) of osteoarthritis as compared to fragment preservation. Significant heterogeneity was identified when comparing between juvenile and adult osteochondritis dissecans. The size of the lesions moderated the between-study heterogeneity with regards to the incidence of osteoarthritis, with the relative risk of osteoarthritis in lesions bigger than 4 cm² being 2.29 (95% CI 1.24-4.23). No other risk factors, including gender of the patient, location of osteochondritis dissecans, stability of osteochondritis dissecans, and surgical versus non-surgical management were significant risk factors.

CONCLUSION

Significant risk factors for osteoarthritis were increased body mass index and fragment excision. Probable but inconclusive risk factors were the age of the patients and the size of the osteochondritis dissecans. The gender of the patient, location of osteochondritis dissecans, the stability of osteochondritis dissecans, and surgical versus non-surgical management of osteochondritis dissecans when appropriate were not significant risk factors.

Comparison of Weightbearing and Nonweightbearing Juvenile Osteochondritis Dissecans Lesions of the Lateral Femoral Condyle

Background:

Repetitive microtrauma may contribute to osteochondritis dissecans (OCD) lesions of the femoral condyle. The effect of differential loading between OCD weightbearing (WB) zones has not been studied.

Purpose:

To determine whether clinical and radiographic variables differ by WB zone in lateral femoral condyle OCD lesions.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively reviewed a consecutive series of patients aged <18 years with lateral femoral condyle OCD lesions presenting at a single institution between 2004 and 2018. Patients with OCD lesions outside of the lateral femoral condyle were excluded. Lesions were localized on radiographs using the Cahill and Berg classification, referencing the Blumensaat line and an extension of the posterior femoral cortex. Progeny bone characteristics evaluated at baseline and 24-month follow-up included ossification, distinct borders from parent bone, and displacement. Baseline lesion dimensions were measured on magnetic resonance imaging (MRI) scans. We evaluated posttreatment pain level, return-to-activity rate, and patient-reported outcome measures (PROMs) including the Pediatric International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Pediatric Functional Activity Brief Scale.

Results:

A total of 62 lateral femoral condyle OCD lesions (mean follow-up, 24.1 months) presented within the study period: 26 WB lesions and 36 nonweightbearing (NWB) lesions. At presentation, no differences between the lesion types were observed in symptom chronicity or symptomatology. NWB lesions were deeper on MRI scans (sagittal depth, 7.11 vs 5.96 mm; P = .046; coronal depth ratio, 0.05 vs 0.01 mm; P = .003), were more likely to develop progeny bone (69.4% vs 44%; P = .047), and demonstrated higher radiographic healing rates (52.8% vs 24%; P = .025) compared with WB lesions. PROMs at follow-up were available for 25 of 62 patients (40.3%), with no statistically significant differences between cohorts at any time. Return to full activity was observed in 72% of WB and 82.1% of NWB lesions (P = .378).

Conclusion:

Lateral femoral condyle OCD lesions of the knee in WB and NWB zones presented similarly at initial evaluation; however, NWB lesions demonstrated higher rates of progeny bone formation and radiographic healing at mean 2-year follow-up.

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

➤

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.

➤

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.

➤

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.

Unestable knee osteochondritis dissecans: arthroscopic fixation with bio-absorbable device

INTRODUCTION

Knee ostheochondritis dissecans is an osteochondral disease, whose treatment is still debated. The purpose this study was to analyze the patients attached with bioabsorbable nail, assisted by arthroscopy.

MATERIAL AND METHOD

Analysis was performed using median and interquartile range (P25-P75), with a follow-up of 9 patients (10 knees) operated for stage III osteochondral lesions. After a minimum of 12 months, the KOOS, IKDC, satisfaction questionnaires were evaluated and a MR control was perfomed.

RESULTS

Bone healing was observed in 80% of patients in the first year, with a delay in union in 20%. The median for age was 15 years. The average follow-up was 5.93 years. All cases were located in the internal condyle. The OCD lesions did not show comminution or necrosis. The 40% of stable lesions, according to preoperative MR, were unestable in arthroscopy and it were attached with internal nail. Two groups of osteochondral lesions were differentiated: juvenile OCD (60%) and adult OCD (40%); all of them were stage III lesions. IKDC questionnaire results were an improvement of 29.5 (22.25, 37.52). In the KOOS questionnaire, an improvement was obtained in symptoms of 18.07, in pain of 29.12, in daily living 25.53, in function (sports, recreational activities) of 35 and in quality of life of 34.42.

CONCLUSIONS

The bioabsorbable nail is a valid, reproducible option for unestable lesions with lesion integrity, with great improvement in function, quality of life and with few complications.

Imaging of Pediatric Lower Limb Sports Injuries

The importance of physical activity during childhood and adolescence has come to light, with an increase in sports-related acute traumatic and overuse injuries as a major disadvantage. A solid understanding of the physiology of the growing skeleton, together with knowledge about age- and sex-related differences in the occurrence of acute traumatic and overuse injuries is necessary. Every musculoskeletal radiologist should also be familiar with the appearances of these injuries on different imaging modalities. This review focuses on all these aspects concerning acute traumatic and overuse injuries among children and adolescents.

Bilateral osteochondral defects of the patellae in an 11-year-old girl

Osteochondral defect or osteochondritis dissecans (OCD) of the knee usually affects young, active populations. It is a challenging diagnosis as patients typically present with poorly localised activity-related pain, which is non-specific and covers many differentials. We present an active 11-year-old girl with bilateral osteochondral defects of the patellae: a rare clinical disorder which was affecting her sporting activities. She had a 12-month history of bilateral anterior knee pain before the diagnosis was achieved with appropriate imaging. Her pain significantly improved with activity modification and physiotherapy. Follow-up will require outpatient clinic assessment and imaging to determine if non-operative management continues to be successful or surgery may be required. This case report emphasises the importance of appropriate high index of suspicion when managing patients with non-specific knee pain. It also demonstrates the importance of judicious use of imaging to avoid a missed or delayed diagnosis.

Idiopathic arteriopathy-induced focal osteonecrosis of the femoral head in a young dog

CASE DESCRIPTION

A 15-month-old 6.5-kg (14.3-lb) castrated male mixed-breed dog was evaluated because of a 4-month history of progressive intermittent non-weight-bearing lameness of the left pelvic limb.

CLINICAL FINDINGS

Orthogonal radiography of the hip joints revealed a 4-mm atypical radiolucent lesion on the distal caudomedial aspect of the left femoral head and a disproportionately large-diameter femoral medullary canal with a low canal flare index. Prolonged unresponsiveness to medical management and progressive enlargement of the lesion prompted the recommendation for total hip replacement (THR).

TREATMENT AND OUTCOME

THR was performed to restore pain-free function of the left pelvic limb and normal activity. A circular osteochondral flap was grossly evident on the femoral head. Histopathologic findings for this portion of the bone indicated an arteriopathy-induced focal subchondral osteonecrosis that had resulted in articular surface collapse. The noted idiopathic arteriopathy had disrupted the normal blood supply to the affected area. On reexamination and radiographic evaluation 13 months after THR, the dog appeared to have pain-free function of the affected limb and had returned to normal activity with no reported complications or problems.

CLINICAL RELEVANCE

To the authors' knowledge, this report represented the first description of arteriopathy-induced focal osteonecrosis of the caudomedial aspect of the femoral head and its successful treatment in a young dog. This type of lesion may more commonly be the cause of hip joint osteoarthritis in young dogs than previously recognized because establishing a definitive diagnosis requires early recognition and histologic evaluation before advanced degenerative changes develop that obscure the underlying etiology.

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.

PLCγ1 inhibition combined with inhibition of apoptosis and necroptosis increases cartilage matrix synthesis in IL-1β-treated rat chondrocytes

Osteoarthritis (OA) is an age‐related, chronic degenerative disease. With the increasing median age of the population, this disease has become an important public health problem. New, disease‐modifying therapies are needed. A potential novel molecular target is phospholipase Cγ1 (PLCγ1), a critical enzyme with important functions including calcium signaling regulation and cell proliferation. In rat chondrocytes treated with IL‐1β (20 ng·mL⁻¹ for 36 h), inhibition of PLCγ1 with U73122 (2 μm for 12 h) increased levels and expression of the cartilage matrix components Collagen2 and Aggrecan. This beneficial effect of PLCγ1 inhibition was counteracted by increased chondrocyte apoptosis and necroptosis, increased cell death, and increase levels of ROS, all potentially negative for OA. Combined treatment of IL‐1β + U73122‐treated chondrocytes with inhibitors of apoptosis (Z‐VAD, 10 μm) and necroptosis (Nec‐1, 30 μm) enhanced the increases in levels and expression of Collagen2 and Aggrecan, and prevented the increases in cell death and ROS levels. These results suggest that PLCγ1 inhibition may be a viable approach for an OA therapy, if combined with targeted inhibition of chondrocyte apoptosis and necroptosis.

Review of Synthetic and Hybrid Scaffolds in Cartilage Tissue Engineering

Cartilage tissue is under extensive investigation in tissue engineering and regenerative medicine studies because of its limited regenerative potential. Currently, many scaffolds are undergoing scientific and clinical research. A key for appropriate scaffolding is the assurance of a temporary cellular environment that allows the cells to function as in native tissue. These scaffolds should meet the relevant requirements, including appropriate architecture and physicochemical and biological properties. This is necessary for proper cell growth, which is associated with the adequate regeneration of cartilage. This paper presents a review of the development of scaffolds from synthetic polymers and hybrid materials employed for the engineering of cartilage tissue and regenerative medicine. Initially, general information on articular cartilage and an overview of the clinical strategies for the treatment of cartilage defects are presented. Then, the requirements for scaffolds in regenerative medicine, materials intended for membranes, and methods for obtaining them are briefly described. We also describe the hybrid materials that combine the advantages of both synthetic and natural polymers, which provide better properties for the scaffold. The last part of the article is focused on scaffolds in cartilage tissue engineering that have been confirmed by undergoing preclinical and clinical tests.

MRI evaluation of articular cartilage in patients with juvenile osteochondritis dissecans (JOCD) using T2∗ mapping at 3T

OBJECTIVE

Evaluate articular cartilage by magnetic resonance imaging (MRI) T2∗ mapping within the distal femur and proximal tibia in adolescents with juvenile osteochondritis dissecans (JOCD).

DESIGN

JOCD imaging studies acquired between August 2011 and February 2019 with clinical and T2∗ mapping MRI knee images were retrospectively collected and analyzed for 31 participants (9F/22M, 15.0 ± 3.8 years old) with JOCD lesions in the medial femoral condyle (MFC). In total, N = 32 knees with JOCD lesions and N = 14 control knees were assessed. Mean T2∗ values in four articular cartilage regions-of-interest (MFC, lateral femoral condyle (LFC), medial tibia (MT), and lateral tibia (LT)) and lesion volume were measured and analyzed using Wilcoxon-rank-sum tests and Spearman correlation coefficients (R).

RESULTS

Mean ± standard error T2∗ differences observed between the lesion-sided MFC and the LFC in JOCD-affected knees (28.5 ± 0.9 95% confidence interval [26.8, 30.3] vs 26.3 ± 0.7 [24.8, 27.7] ms, P = 0.088) and between the affected- and control-knee MFC (28.5 ± 0.9 [26.8, 30.3] vs 28.5 ± 0.6 [27.1, 29.9] ms, P = 0.719) were nonsignificant. T2∗ was significantly increased in the lesion-sided MT vs the LT for the JOCD-affected knees (21.5 ± 0.7 [20.1, 22.9] vs 18.0 ± 0.7 [16.5, 19.5] ms, P = 0.002), but this same difference was also observed between the MT and LT in control knees (21.0 ± 0.6 [19.7, 22.3] vs 18.1 ± 1.1 [15.8, 20.4] ms, P = 0.037). There was no significant T2∗ difference between the affected- and control-knee MT (21.5 ± 0.7 [20.1, 22.9] vs 21.0 ± 0.6 [19.7, 22.3] ms, P = 0.905). T2∗ within the lesion-sided MFC was not correlated with patient age (R = 0.20, P = 0.28) or lesion volume (R = 0.06, P = 0.75). T2∗ values were slightly increased near lesions in later-stage JOCD subjects but without statistical significance.

CONCLUSIONS

T2∗ relaxations times were not significantly different from control sites in the articular cartilage overlying JOCD lesions in the MFC or adjacent MT cartilage in early-stage JOCD.

Osteochondritis Dissecans of the Knee: Arthroscopic Suture Anchor Fixation

Osteochondritis dissecans (OCD) is a subchondral bone abnormality, in which subchondral bone and the overlying articular cartilage detach from the bony bed. Multiple techniques for OCD fixation have been described, including metallic, bioabsorbable implants and biological fixation. We describe a surgical technique for OCD lesions including bony bed preparation with curettage and microfracture, anatomic reduction, and fixation using a suture anchor to provide stability and healing of the lesion.

Osteochondritis Dissecans of the Knee: Short-Term Outcomes of a Hybrid Technique to Restore a Partially Salvageable Progeny Fragment

OBJECTIVE

This retrospective case series describes a hybrid fixation technique and determines the clinical outcomes, knee function, and activity level of patients at short-term follow-up.

DESIGN

Seventeen patients (18 knees) with unstable osteochondritis dissecans (OCD) lesions involving the knee were treated with a hybrid fixation technique in which the salvageable fragment was fixed and osteochondral autograft transplantation system (OATS) was used for the unsalvageable fragment. Thirteen lesions involved the medial femoral condyle, 4 involved the lateral femoral condyle, and 1 involved the patella. Mean patient age was 17 years (range 12-28 years). All lesions were International Cartilage Repair Society (ICRS) grade III or IV. The patients were prospectively followed postoperatively. Outcome measures included the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and the Tegner activity scale.

RESULTS

At mean follow-up of 36 months (range 24-67.2 months), the mean postoperative KOOS scores, given as mean (SD), were as follows: Quality of Life (QoL) 91.1 (17.0), Activities of Daily Living (ADL) 99.5 (1.5), Sport 94.5 (11.2), Pain 97.4 (5.8), and Symptoms 95.9 (6.5). Mean IKDC score was 96.2 (7.0). There was no significant difference between mean preinjury (7.95, SD = 1.1) and mean postoperative (7.45, SD = 1.5) Tegner scores (P = 0.363). The mean Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was 87.5 at a mean 7.8 months (range 3-18 months) postoperation. There were no reported complications.

CONCLUSION

The results of this case series suggest that patients with partially salvageable OCD lesions involving the knee can have positive short-term outcomes and can expect a low complication rate when treated with a hybrid technique of fixation with osteochondral autograft transfer.

A global bibliometric and visualized analysis in the status and trends of subchondral bone research

BACKGROUND

Structural and functional changes in subchondral bone have been recognized as a key factor in the development of related disease, and subchondral bone may be a new target for the treatment of osteoarthritis. The purpose of our present study is to investigate the global status and trends of subchondral bone research.

METHOD

Publications related to the studies of subchondral bone from 1993 to 2018 were retrieved from the Science Citation Index-Expanded Web of Science database. The data source was studied and indexed by using bibliometric methodology. For visualized study, bibliographic coupling analysis, co-authorship analysis, co-citation analysis, co-occurrence analysis and the analysis of publication trends in subchondral bone research were conducted by VOS viewer and GraphPadPrism 5 software.

RESULTS

A total of 4780 publications were included. There is an increasing trend of the relative research interests and number of publications per year globally. The cumulative number of publications about subchondral bone research followed the logistic growth model (Equation is included in full-text article.). The USA made the highest contributions to the global research with the most citations, the highest H-index, and the most total link strength, while Denmark had the highest average citation per item. The journal Osteoarthritis and Cartilage had the largest publication number. Boston University is the most contributive institution. Studies could be divided into 4 clusters: "Mechanism research", "Animal study", "Clinical study" and "Pathological features". Less efforts were put into clinical study.

CONCLUSION

The number of publications about subchondral bone research would be increasing in the next years based on the current global trends. Attention should be drawn to the latest popular research, including "Mesenchymal stem-cells", "Autologous chondrocyte implantation", "Microfracture" and "Pain". Therefore, more and more efforts will be put into mechanism research on subchondral bone, which may inspire new clinical treatments for osteoarthritis and other related diseases based on subchondral bone.

Large chondral fragment of the lateral femoral condyle treated with arthroscopic internal fixation in an elite young athlete - A case report

Focal chondral lesions in the adolescent population create a particular challenge for orthopedic surgeons, and currently there exists no consensus on proper treatment. Numerous techniques for addressing focal chondral defects are employed in both pediatrics and adults, including fragment excision, debridement and fixation, bone marrow stimulation and microfracture techniques, cell-based options, as well as chondral and osteochondral grafts. Although historical evidence is mixed, recent reports of primary fixation of displaced cartilage fragments have shown favorable results. We present a case of reduction and fixation of a large displaced cartilage lesion in an elite young tennis player. Our results, in addition to other reports mentioned in this manuscript, highlight the importance of considering primary fixation of large chondral lesions when amenable to repair.

Osteochondral Allograft Transplantation of the Medial Femoral Condyle With Orthobiologic Augmentation and Graft-Recipient Microfracture Preparation

Osteochondritis dissecans (OCD) has been recognized for over 100 years yet still poses treatment challenges owing to both the avascular nature of articular cartilage and the inability to generate hyaline cartilage. The knee is most commonly involved, and without repair, patients have chronic knee pain, loose bodies, and early-onset osteoarthritis. There are a number of surgical techniques for repairing OCD, some of which are still being refined. Currently, common procedures used to treat OCD lesions include microfracture, autologous chondrocyte implantation, osteochondral autograft transplantation, and osteochondral allograft transplantation. In this Technical Note, we describe osteochondral allograft transplantation with the addition of platelet-rich plasma and graft-recipient microfracture. We believe the micropores augment the osteoconductive and osteoinductive properties of the allograft and aid in the incorporation of the allograft plug by improving angiogenesis, enhancing clot formation in the allograft, and providing a homogeneous environment for remodeling.