Osteochondritis Dissecans of the Knee

Bilateral juvenile osteochondrosis dissecans in monozygotic twins: a case report

INTRODUCTION

The etiology of osteochondrosis dissecans (OCD), a chondropathy associated with detachment of the subchondral bone and the overlaying cartilage, is not yet fully understood. While repetitive physical exercise-related stress is usually assumed to be the main risk factor for the occurrence of OCD, genetic predisposition could have an underestimated influence on the development of the disease.

CASE REPORT

We report a case of monozygotic twins with almost identical stages of bilateral osteochondrosis dissecans of the knee joint. In both patients, initially, a unilateral lesion occurred; despite restricted physical exercise, in the further course of the disease a lesion also developed on the contralateral side. While the lesion found most recently demonstrated an ongoing healing process at a 6-month follow-up, the other three lesions showed a natural course of healing under conservative treatment with significant clinical as well as radiological improvements after one year and complete consolidation in magnetic resonance imaging (MRI) after 2 years.

CONCLUSION

There could be a genetic component to the development of OCD, although this has not yet been proven. Based on a two-year MRI follow-up, we were able to show the self-limiting characteristics of juvenile osteochondrosis dissecans.

Bilateral osteochondritis dissecans of the knee in pediatric and adolescent patients presenting with unilateral symptoms: An epidemiological and radiographic analysis

Purpose

This study aims to determine the prevalence and characteristics of bilateral osteochondritis dissecans of the knee in patients presenting with unilateral symptoms and compare this cohort to patients with unilateral disease.

Methods

Records of patients ≤18 years old from 2003 to 2016 with a diagnosis of osteochondritis dissecans of the knee and strictly unilateral knee pain were identified. Contralateral (asymptomatic) knee imaging within 1 year of initial presentation was required. Lesion characteristics were evaluated by assessing size, location, and Hefti staging. Both surgical and nonoperative treatments were recorded. Patients with unilateral osteochondritis dissecans were compared to those with bilateral disease.

Results

Eighty patients, 63 males (79%) and 17 females (21%), with an average age of 13.1 years old, were included. Twenty (25%) of the presenting/symptomatic lesions were deemed stable on magnetic resonance imaging. A positive correlation between lesion size and Hefti classification was appreciated. Twelve patients (15%) were found to have bilateral osteochondritis dissecans on contralateral imaging. There was no significant difference in skeletal maturity between patients with bilateral versus unilateral disease. Fifty-two patients (77%) with unilateral disease underwent surgical intervention, while 9 (75%) of those with bilateral disease underwent surgery on either knee. In patients with an asymptomatic contralateral lesion, 67% ultimately underwent surgical intervention on the contralateral knee.

Conclusions

In patients presenting with unilateral osteochondritis dissecans symptoms, there was a 15% prevalence of bilateral disease, with no difference in age, sex, physeal status, or lesion characteristics between patients with unilateral vs bilateral osteochondritis dissecans lesions. Given the prevalence of asymptomatic contralateral lesions and the required intervention, this study supports early bilateral radiologic knee evaluation.

Level of evidence

IV, Retrospective Case series.

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.

No difference in patient reported outcomes between cohorts undergoing lesion-specific surgery for osteochondritis dissecans of the knee

Introduction

There is a paucity of data on patient reported outcome measures (PROMs) associated with surgical treatment of osteochondritis dissecans (OCD). As a result, preoperative patient and family counseling regarding expected outcomes is difficult. The purpose of this study was to compare pre-to post-operative changes in PROMs amongst cohorts of patients with OCD that underwent one of three lesion-specific surgical treatments: 1) transarticular drilling for stable lesions, 2) drilling and fixation for unstable lesions 3) grafting for unsalvageable lesions.

Methods

The electronic medical records of pediatric and adolescent patients with knee OCD, at a single institution between January 2017 and August 2019, were reviewed. Patients were categorized into one of three surgical groups, with initial determination confirmed at the time of surgery during diagnostic knee arthroscopy. Differences between groups were assessed with one-way analysis of variance (ANOVA).

Results

Of the 78 patients included in this study, 49 (62.8%) were male with a mean age of 13.5 ± 2.2 years. There was no significant difference between the surgical groups for baseline HSS Pedi-FABS (P = 0.58) or PROMIS Mobility (P = 0.47). There were no significant differences in PROMIS PI scores at baseline (P = 0.32), at latest follow-up (P = 0.72), or in interval change from baseline to follow-up (P = 0.42), between the three surgical groups.

Conclusion

Lesion-specific surgical management of OCD led to similar improvements in PROMIS PI at a minimum of one-year follow-up. These results may better allow surgeons to reassure patients and families that outcomes are similar when lesions are treated through a lesion-specific algorithm.

Level of evidence

Level IV: Retrospective cohort study.

Low-Intensity Pulsed Ultrasonography Plus Arthroscopic Drilling Does Not Improve Bone Healing More Than Arthroscopic Drilling Alone in Pediatric Patients With Stable Osteochondritis Dissecans of the Knee

Purpose

To determine whether adjuvant use of bone stimulation would improve the rate of healing in the operative management of stable osteochondritis dissecans (OCD) of the knee in pediatric patients.

Methods

This retrospective matched case-control study was performed at a single tertiary care pediatric hospital between January 2015 and September 2018. Patients who underwent antegrade drilling for stable femoral condyle OCD with greater than 2 years' follow-up were included. Preference was for all to receive postoperative bone stimulation; however, some were denied because of insurance coverage. This enabled us to create 2 matched groups of those who received postoperative bone stimulation and those who did not. Patients were matched on skeletal maturity, lesion location, sex, and age at surgery. The primary outcome measure was the rate of healing of the lesions determined by postoperative magnetic resonance imaging measurements at 3 months.

Results

Fifty-five patients were identified who met the inclusion and exclusion criteria. Twenty patients from the bone stimulator group (BSTIM) were matched to 20 patients from the no bone stimulator group (NBSTIM). Mean age for BSTIM at surgery was 13.2 years ± 2.0 (range, 10.9-16.7) and for NBSTIM at surgery 12.9 years ± 2.0 (range, 9.3-17.3). At 2 years, 36 patients (90%) in both groups went on to clinical healing without further interventions. In BSTIM, there was a mean decrease of 0.9 (±1.8) mm in lesion on coronal width and 12 patients (63%) had overall improved healing; in NBSTIM there was a mean decrease of 0.8 (±3.6) mm in coronal width and 14 patients (78%) had improved healing. No statistical differences in the rate of healing were found between the 2 groups (P = .706).

Conclusion

In antegrade drilling of stable knee OCD lesions in pediatric and adolescent patients, adjuvant bone stimulator use did not appear to improve radiographic or clinical healing.

Level of evidence

Level III, retrospective case-control study.

Osteonecrosis of the Knee: Not all Bone Edema is the Same

Knee pain is among the most common complaints that an orthopedic surgeon may see in practice. It is often worked up with X-rays and MRI, leading to a myriad of potential diagnoses ranging from minimal edema patterns to various types of osteonecrosis. Similarities in certain causes can pose diagnostic challenges. The purpose of this review was to present the 3 types of osteonecrosis observed in the knee as well as additional causes to consider to help aid in the diagnosis and treatment..

Validation of a Novel Magnetic Resonance Imaging Classification for Osteochondritis Dissecans of the Knee

BACKGROUND

The novel Kocher classification is a 3-group magnetic resonance imaging (MRI) classification system for osteochondritis dissecans (OCD) of the knee that was shown to have comparable reliability to that of the established 5-group Hefti classification. The purpose of this study was to evaluate the validity and clinical utility of this simplified system as an alternative to the Hefti classification.

METHODS

Demographic data and arthroscopic findings were retrospectively collected from medical and surgical records of 144 consecutive knees in children with arthroscopically diagnosed knee OCD. OCD lesions on preoperative MRIs and surgical reports (serving as the reference standard) were assessed by independent raters and assigned both a Kocher and Hefti classification. Agreement between MRI classification and arthroscopic findings for both systems was assessed using weighted kappa (kw) coefficients. Validation, accuracy, sensitivity, and specificity were measured by comparing a dichotomized Kocher classification for MRI and arthroscopy, and by estimating Cohen kappa (kc) coefficients. Agreement between arthroscopic findings and treatment type was measured using the Spearman correlation coefficient.

RESULTS

Inter-rater reliability between the 2 MRI raters was substantial for the Kocher classification [ka=0.66; 95% confidence interval (CI)=0.56-0.75] and moderate for the Hefti classification (ka=0.57; 95% CI=0.47-0.67). There was no difference detected in the agreement statistics for Kocher versus Hefti classifications (P=0.89). Binary agreement using dichotomized Kocher classifications was worse than the 3-group category classification. When dichotomized, combining Kocher grades 1 and 2 demonstrated moderate agreement (kc=0.41; 95% CI=0.25-0.58), and combining grades 2 and 3 demonstrated fair agreement (kc=0.34; 95% CI=0.21-0.48). There was a strong correlation between arthroscopy-based finding and treatment category for both the Kocher classification (r=0.85; 95% CI=0.80-0.89) and the Hefti classification (r=0.82; 95% CI=0.75-0.86).

CONCLUSION

The validity and clinical utility of the newer 3-group Kocher classification for knee OCD is comparable to that of the well-established 5-group Hefti classification. Both systems help determine lesion stability and characteristics on MRI, which correlate closely to arthroscopic findings. This simplified classification system, with less uncertainty, provides a foundation for further outcomes research to develop an evidence-based algorithm for effective surgical management of OCD lesions of the knee.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Arthroscopic Drilling for Stable Juvenile Osteochondritis Dissecans of the Knee Is Safe and Patients Reliably Return to Daily Activities by 3 Months

Purpose

To assess the postoperative timeline for the return to activities of daily living (ADLs) in pediatric patients after arthroscopic drilling of a stable osteochondritis dissecans (OCD) lesion of the knee and to determine the rate of and risk factors for complications after the procedure.

Methods

In a retrospective chart review, data from all patients aged 18 years or younger who underwent arthroscopic drilling for a stable OCD lesion of either femoral condyle from May 2009 through July 2017 were collected. Demographic data, lesion characteristics, operative data, postoperative course, radiographic outcomes, and complications were recorded. Statistical analysis was performed to determine the risk factors for reoperations.

Results

A total of 139 knees in 131 patients were evaluated, with a mean age of 12.7 years, of which 102 (73%) were male knees. The average follow-up period was 17.8 ± 13.2 months after surgery. All patients regained full extension and flexion within 5° of the contralateral knee at a mean of 12.9 ± 3.2 weeks postoperatively, with 95% having returned fully to ADLs by the 3-month postoperative visit. No cases of infection, stiffness, arthrofibrosis, or other procedure-related complications were recorded. A total of 133 knees (95.7%) showed healing on radiographs, whereas 6 knees (4.3%) underwent additional surgical procedures, all of which were performed for treatment failure related to nonhealing lesions (including loose body removal, chondroplasty, and repeated drilling). Lesion size was the only significant risk factor for reoperation (P = .02).

Conclusions

Our findings suggest that arthroscopic drilling for stable, intact OCD lesions in the pediatric knee is a safe procedure with reliable outcomes and return to ADLs and a minimal risk of complications. Most patients return to their preoperative daily activity level with a full range of motion of the knee by 3 months after surgery. Complications, including reoperations, are related to the progression of the OCD lesion rather than to the surgical procedure. Each 1-cm² increase in lesion size increases the likelihood of reoperation by 2.93 times.

Level of Evidence

Level IV, therapeutic case series.

Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort

BACKGROUND

Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease.

PURPOSE

To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest.

RESULTS

As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases.

CONCLUSION

The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms.

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.

Novel Magnetic Resonance Imaging Classification of Osteochondritis Dissecans of the Knee: A Reliability Study

BACKGROUND

Current advanced imaging classification systems for osteochondritis dissecans (OCD) of the knee grade severity of disease by identifying certain lesion characteristics. The most widely used are the Hefti and Nelson systems. A novel classification presents a simpler 3-group approach to diagnose knee OCD by magnetic resonance imaging (MRI), compared with the Hefti (5-group) and Nelson (4-group) classifications. The purpose of this study was to compare the reliability of this novel classification with that of the more complex, established systems-an initial step in establishing validity and clinical utility.

METHODS

In total, 120 standardized knee MRIs of patients with established knee OCD were preselected to capture the spectrum of lesion types, with regard to both progression and location of the lesion. Each of the MRIs were independently classified by 2 readers into the novel, Hefti, and Nelson classification systems. A random sample was rereviewed by 1 rater 6 weeks after initial review. The inter-rater and intrarater agreements were evaluated by estimating Krippendorff α.

RESULTS

In total, 106 knees were classified by the novel, Hefti, and Nelson classification systems, as 14 of the knees lacked the necessary MRI sequences. There were no differences in inter-rater and intrarater agreement across classification systems. Krippendorff α for inter-rater agreement was 0.51 (95% confidence interval, 0.33-0.66) for the Hefti classification, 0.50 (0.34-0.64) for the Nelson classification, and 0.49 (0.32-0.65) for the novel classification. The intrarater agreement was 0.88 (0.75-0.97) for the Hefti classification, 0.94 (0.86-0.99) for the Nelson classification, and 0.98 (0.94-1.00) for the novel classification system.

CONCLUSIONS

The novel classification for knee OCD demonstrated near-perfect intrarater agreement and moderate inter-rater agreement, consistent with the current, well-established classification systems. Pending a subsequent study on validity and clinical utility, this simpler classification system may offer an alternative, noninvasive diagnostic method to guide clinical treatment.

LEVEL OF EVIDENCE

Level IV.

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.

➤

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.

➤

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.

Osteochondritis Dissecans of the Knee: An Interrater Reliability Study of Magnetic Resonance Imaging Characteristics

BACKGROUND

Imaging characteristics of osteochondritis dissecans (OCD) lesions quantified by magnetic resonance imaging (MRI) are often used to inform treatment and prognosis. However, the interrater reliability of clinician-driven MRI-based assessment of OCD lesions is not well documented.

PURPOSE

To determine the interrater reliability of several historical and novel MRI-derived characteristics of OCD of the knee in children.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A total of 42 OCD lesions were evaluated by 10 fellowship-trained orthopaedic surgeons using 31 different MRI characteristics, characterizing lesion size and location, condylar size, cartilage status, the interface between parent and progeny bone, and features of both the parent and the progeny bone. Interrater reliability was determined via intraclass correlation coefficients (ICCs) with 2-way random modeling, Fleiss kappa, or Krippendorff alpha as appropriate for each variable.

RESULTS

Raters were reliable when the lesion was measured in the coronal plane (ICC, 0.77). Almost perfect agreement was achieved for condylar size (ICC, 0.93), substantial agreement for physeal patency (ICC, 0.79), and moderate agreement for joint effusion (ICC, 0.56) and cartilage status (ICC, 0.50). Overall, raters showed significant variability regarding interface characteristics (ICC, 0.25), progeny (ICC range, 0.03 to 0.62), and parent bone measurements and qualities (ICC range, -0.02 to 0.65), with reliability being moderate at best for these measurements.

CONCLUSION

This multicenter study determined the interrater reliability of MRI characteristics of OCD lesions in children. Although several measurements provided acceptable reliability, many MRI features of OCD that inform treatment decisions were unreliable. Further work will be needed to refine the unreliable characteristics and to assess the ability of those reliable characteristics to predict clinical lesion instability and prognosis.

Nonoperative treatment of stable juvenile osteochondritis dissecans of the knee: effectiveness of unloader bracing

The purpose of this study was to compare the treatment outcomes of stable juvenile osteochondritis dissecans (JOCD) of the knee in a large cohort treated nonoperatively with unloader bracing versus other nonoperative treatment modalities without unloader bracing. This retrospective study assessed the clinical course of skeletally immature patients who underwent a minimum of 3 months nonoperative treatment for stable JOCD of the femoral condyle at a single institution (2001-2014). Treatment was based on physician preference. Unloader bracing was compared with other 'non-unloader' modalities, with successful nonoperative treatment defined as the avoidance of subsequent surgical intervention. Two hundred ninety-eight patients were included, 219 (73%) of whom were male. The mean ± SD age at diagnosis was 11.5 ± 1.6 years. Thirty-five patients were diagnosed with bilateral OCD, resulting in 333 knees in total. One hundred eighty-seven (56%) knees were treated with unloader bracing for a minimum of 3 months, whereas 146 (44%) were treated with other nonoperative modalities. All patients were treated with activity restrictions. Weight-bearing restrictions were applied for a total of 83 (25%) cases, for durations ranging from 19 to 196 days (median: 46 days) and at similar rates across groups. Nonoperative treatment was successful in 189 (57%) knees with a median follow-up of 9.5 months (interquartile range: 5.9-15.7 months). Surgical intervention was required in 144 (43%) knees at a median time of 6.0 months (interquartile range: 4.1-10.5 months). The unloader bracing group more often required surgical intervention when compared with the nonunloader group [93/187 (50%) vs. 51/146 (35%) knees, respectively; P = 0.02]. Male sex (P = 0.05) and Hefti stage I (P = 0.05) showed possible associations with nonoperative treatment success. Nonoperative treatment for stable JOCD of the knee leads to the avoidance of subsequent surgical intervention in 57% of cases. Unloader bracing is not associated with significantly improved outcomes when compared with other nonoperative modalities. Level of Evidence: III Retrospective Comparative Case Series.

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

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

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

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

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

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

Contact force between the tibial spine and medial femoral condyle: A biomechanical study

BACKGROUND

Contact between the tibial spine and medial femoral condyle with internal tibial rotation (ITR) has been proposed as a factor for the development of osteochondritis dissecans lesions. We hypothesized that tibial spine contact force (CF) would increase significantly with applied internal tibial torque (IT).

METHODS

A 20 mm diameter cylinder of bone encompassing the tibial spine was cored and attached to a load cell. The isolated bone cylinder included the tibial attachments of the anterior cruciate ligament (ACL) and anterior horn of the lateral meniscus (AHLM). Eleven human cadaveric knees were flexed from 0°-50° under 200 N of tibiofemoral compression (TFC), without and with 2 N-m IT. Tests were repeated with the AHLM cut, and again with both AHLM and ACL cut, where the load cell recorded CF alone without contributions from any ligamentous attachments.

FINDINGS

There were no significant differences in CF, ITR, or valgus tibial rotation (VTR) after sectioning the AHLM, without or with applied IT. With no tibial torque, mean CFs were less than 20 N throughout the flexion range. Addition of IT significantly increased 1) mean CF by 44.4 N(SD 15.8 N) at 0°(+240%) and 27.2 N(SD 5.0 N) at 20°(+675%), 2), mean ITR by 10.2°(SD 0.8°) at 0° flexion and 18.6°(SD 2.0°) at 20° flexion, and 3) mean VTR by 1.3°(SD 0.4°) at 0° flexion and 4.4°(SD 0.8°) at 20° flexion.

INTERPRETATION

Our hypothesis was confirmed only between 0° and 20° of knee flexion, where the intercondylar separation distance is relatively small and the possibility of tibial spine contact with ITR is greater.

Cartilage diseases

Hyaline cartilages, fibrocartilages and elastic cartilages play multiple roles in the human body including bearing loads in articular joints and intervertebral discs, providing joint lubrication, forming the external ears and nose, supporting the trachea, and forming the long bones during development and growth. The structure and organization of cartilage's extracellular matrix (ECM) are the primary determinants of normal function. Most diseases involving cartilage lead to dramatic changes in the ECM which can govern disease progression (e.g., in osteoarthritis), cause the main symptoms of the disease (e.g., dwarfism caused by genetically inherited mutations) or occur as collateral damage in pathological processes occurring in other nearby tissues (e.g., osteochondritis dissecans and inflammatory arthropathies). Challenges associated with cartilage diseases include poor understanding of the etiology and pathogenesis, delayed diagnoses due to the aneural nature of the tissue and drug delivery challenges due to the avascular nature of adult cartilages. This narrative review provides an overview of the clinical and pathological features as well as current treatment options available for various cartilage diseases. Late breaking advances are also described in the quest for development and delivery of effective disease modifying drugs for cartilage diseases including osteoarthritis, the most common form of arthritis that affects hundreds of millions of people worldwide.

Catcher's Knee: Posterior Femoral Condyle Juvenile Osteochondritis Dissecans in Children and Adolescents

BACKGROUND

Juvenile osteochondritis dissecans is an idiopathic condition involving subchondral bone and articular cartilage in skeletally immature patients in whom the growth plates are open, potentially leading to lesion instability. Because of the differing forces experienced by baseball/softball catchers versus position players, the age at which lesions develop and the characteristics of the lesions themselves may differ between these 2 populations. The purpose of the study was to examine relative age and characteristics of osteochondritis dissecans (OCD) knee lesions in catchers compared with position players.

METHODS

Using a text-based search tool that queries clinic notes and operative reports, computerized medical records from 1990 to 2014 from the Sports Medicine Program of a tertiary care Children's Hospital were searched to find children and adolescents who had OCD of the knee, played baseball/softball, had a specified field position, and had magnetic resonance imaging of the knee. Ultimately, 98 knees (78 patients) were identified: 33 knees (29 patients) in catchers and 65 knees (49 patients) in noncatchers. Data collected included position played (catcher/noncatcher), demographics (age, unilateral/bilateral, and sex), lesion severity, and sagittal and coronal lesion location.

RESULTS

When compared with noncatchers, catchers presented at a younger age (P=0.035) but were similar with respect to bilateral involvement (P=0.115), sex (P=0.457), and lesion severity (P=0.484). Lesions in catchers were more posterior on the femoral condyle in the sagittal plane (P=0.004) but similar in location in the coronal plane (P=0.210).

CONCLUSIONS

Catchers developed OCD at a younger age and in a more posterior location on the medial and lateral femoral condyles than noncatchers. These results may represent the effects of repetitive and persistent loading of the knees in the hyperflexed position required of catchers. Increased awareness of this risk may lead to surveillance and prevention programs.

LEVEL OF EVIDENCE

Level III-case-control study.

Clinical Outcomes of Osteochondral Allograft Transplantation for Secondary Treatment of Osteochondritis Dissecans of the Knee in Skeletally Mature Patients

PURPOSE

To report clinical outcomes of osteochondral allograft transplantation (OCA) for skeletally mature patients with osteochondritis dissecans (OCD) lesions of the knee in whom prior surgical intervention has failed, and to describe return-to-sport (RTS) rates and any predictive demographic or preoperative variables associated with a higher likelihood to RTS.

METHODS

Patients who underwent OCA by a single surgeon (B.J.C.) between October 1, 2002, and November 30, 2014, for a diagnosis of OCD with a minimum of 2 years' follow-up were included. Demographic, surgical history, operative, and postoperative data points including RTS were analyzed for all patients collectively, with subanalysis to identify any demographic and operative variables associated with the ability to RTS. Failure was defined as revision OCA, gross appearance of graft failure on second-look arthroscopy, or conversion to arthroplasty.

RESULTS

We identified 41 consecutive patients (43 knees), with 37 patients (39 knees, comprising 26 male and 13 female knees) available for clinical follow-up at an average of 7.29 ± 3.30 years. There was significant improvement (P < .05) in all patient-reported outcome scores, with the exception of the Short Form 12 mental subscale (P = .910). Most patients (81.6%) reported being either mostly satisfied or completely satisfied at final follow-up. Of patients self-identifying as athletes preoperatively (n = 22), 18 (81.8%) achieved RTS at an average of 14.0 ± 8.7 months. Athletes with failure to RTS had a significantly greater body mass index (RTS, 24.68 ± 3.67; no RTS, 27.82 ± 0.69; P = .005). Subsequent surgery was performed in 14 patients (35.9%), and primary OCA failed in 2 patients at an average of 6.2 ± 3.8 years.

CONCLUSIONS

OCA is a successful secondary surgical treatment for OCD of the knee in skeletally mature patients and leads to clinically meaningful improvements in patient-reported outcome scores and high patient satisfaction and RTS rates in low-level athletes at an average of 7.29 years' follow-up. Athletes with failure to RTS were found to have a significantly higher body mass index. Although reoperation may be common after OCA (35.9%), the failure rate is low (5.1%) in this series.

LEVEL OF EVIDENCE

Level IV, case series.

Incidence of symptomatic osteochondritis dissecans lesions of the knee: a population-based study in Olmsted County

OBJECTIVE

To (1) define population-based incidence of knee Osteochondritis dissecans (OCD) lesions using the population of Olmsted County, (2) examine trends over time, and (3) evaluate rate of surgical management over time.

METHOD

Study population included 302 individuals who were diagnosed with knee OCD lesions between January 1, 1976 and December 31, 2014. Complete medical records were reviewed to extract injury and treatment details. Age- and gender-specific incidence rates were calculated and adjusted to the 2010 US population. Poisson regression analyses were performed to examine incidence and surgery trends by age, gender, and calendar period.

RESULTS

Overall age- and gender-adjusted incidence annual incidence of knee OCD lesions was 6.09 per 100,000 person-years. The incidence was significantly higher (P < 0.001) in males (8.82, 95% CI 7.63 to 10.00 per 100,000) compared to females (3.32, 95% CI 2.61 to 4.04 per 100,000). Age- and gender-specific incidence was highest in both males and females in the 11-15 years old at 39.06 and 16.15 per 100,000, respectively. In males aged 11-15 years, OCD incidence increased significantly over the study period from 20.68 in 1976-1985 to 48.16 in 2006-2014 (per 100,000).

CONCLUSIONS

Overall age- and gender-adjusted annual incidence of knee OCD lesions in the Olmsted Country Population was 6.09 per 100,000 person-years with a significantly higher incidence in males compared to females. The highest incidence for both males and females occurred between the ages 11-15 years. Trends indicate increasing OCD incidence in younger males and decreasing surgical management in females over the last decade.

Paediatric fractures around the knee

Paediatric fractures around the knee are not common but their incidence seems to be increasing as a result of the increasing number of children participating in sports. Given the characteristics of the growing skeleton, specific fractures only occur in children. Diagnosis is mainly based on history, clinical examination and plain radiographs. Advanced imaging may be required in special fracture types. Although many of these injuries can be managed non-operatively, early referral to a specialist team is necessary to avoid delays in surgical management and to reduce the risk of acute or late complications.