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

[Non-traumatic osteochondral lesions of the knee joint during growth : Juvenile osteochondritis dissecans (JOCD) of the knee]

BACKGROUND

Juvenile osteochondritis dissecans of the knee joint is the most common osteochondral lesion during growth, usually occurring between the 10th and 14th year of age.

PATHOGENESIS

Repetitive microtraumata lead to a subchondral osseus lesion, which is commonly located at the medial aspect of the femoral condyle. Sport activities are considered to be the main cause, although genetic and hereditary factors as well as vitamin D3 deficiency also play a role. Current classification systems distinguish between stable and unstable osteochondral lesions, which is decisive for further treatment.

TREATMENT

Stable lesions may heal through conservative treatment by avoiding weight bearing and sport. Unstable lesions, on the other hand, can lead to a complete defect of the joint surface with the formation of a free joint body. In such cases, various surgical techniques aim at reconstructing the surface of the joint, in order to reduce the risk of secondary arthritis.

All-Arthroscopic Bone Grafting and Primary Fixation of a Medial Femoral Condyle Osteochondritis Dissecans Lesion

Treatment of osteochondritis dissecans (OCD) lesions poses a significant challenge for orthopaedic surgeons and can cause debilitating limitations on the activity of patients. Timing of intervention, surgical technique, and selection of graft when needed are all key elements of treatment that need to be considered carefully and discussed with patients. Primary fixation of an OCD fragment with intact subchondral bone has been shown to be beneficial in some cases. There is limited literature, however, on how to approach large chondral lesions in young patients without a large subchondral base attached to the fragment. Treatment of large OCD lesions of the knee with an all-arthroscopic approach provides several benefits, including limited dissection for exposure, improved ability to assess the stability of the OCD lesion during articulation after fixation, and an expedited recovery compared to an open approach. The purpose of this technical note is to detail a technique of performing an all-arthroscopic bone grafting and primary fixation of a medial femoral condyle OCD lesion.

Suture-Bridge Fixation of Osteochondral Fractures and Osteochondritis Dissecans in the Knee: Excellent Rates of Early Lesion Stability and Osseous Union

BACKGROUND

Preservation of articular cartilage in the setting of acute or chronic injury in the adolescent and young adult knee is paramount for long-term joint health. Achieving osseous union, minimizing implant-related injury, and eliminating the need for reoperation for traumatic chondral and osteochondral lesions (OCLs) and osteochondritis dissecans (OCD) remain a challenge for the orthopaedic surgeon.

PURPOSE

To evaluate radiographic healing, patient-reported outcomes, and short-term complications after suture-bridge fixation of chondral fragments, osteochondral fractures, and OCD lesions in the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study included consecutive patients (38 patients, 40 knees) treated within a single academic sports medicine institution who underwent suture-bridge fixation of an OCL or an OCD lesion of the knee from initiation of the technique in October 2019 through March 2021. The suture-bridge technique entailed bioabsorbable knotless anchors placed on the outside margins of the lesion with multiple strands of hand-tensioned absorbable (No. 0 or No. 1 Vicryl) or nonabsorbable (1.3-mm braided polyester tape) bridging suture. Healing was assessed by radiography and magnetic resonance imaging (MRI), with MRI scans obtained on all OCD lesions and any chondral-only lesions. MRI scans were available for 33 of 40 (82.5%) knees within 1 year of surgery and were evaluated for lesion healing. Complications and rates and timing of return to sport were evaluated. Patient-reported outcomes in the OCD cohort were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) to determine early pain and functional improvement.

RESULTS

In total, 33 (82.5%) lesions demonstrated full union, and no lesions failed treatment. MRI assessment of healing (mean, 5.8 months; range, 3-12 months) demonstrated 9 (64.3%) OCD lesions with full union, 5 (35.7%) OCD lesions with stable union, and no OCD lesions with nonunion. Of the OCLs, 17 (89.5%) had full union, 2 (10.5%) had stable union, and none had nonunion. The 7 bony OCLs without an MRI scan demonstrated complete radiographic union. In 30 (75.0%) lesions, patients returned to sports at a mean of 6.5 months (range, 3.8-10.2 months). KOOS Activities of Daily Living, Pain, Quality of Life, and Symptoms scores demonstrated significant improvement from baseline at 6 months and at 1 year. There were 2 (5%) complications, consisting of reoperation for marginal chondroplasty on an otherwise stable lesion, and re-operation for intial un-treated patellar instability, with no reoperations for failure or revision of the suture-bridge construct.

CONCLUSION

In this series of OCLs and OCD lesions of the knee, suture-bridge fixation demonstrated excellent rates of MRI and radiographic union and good early outcomes with minimal short-term complications. This technique may be used for lesion salvage as an alternative to metallic and nonmetallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation are warranted.

Refixation of a Large Osteochondral Fragment with Magnesium Compression Screws-A Case Report

INTRODUCTION

Osteochondrosis dissecans (OCD) is a disease affecting the subchondral bone and the overlying articular cartilage. The etiology is most likely a combination of biological and mechanical factors. The incidence is highest in children >12 years old and it predominantly affects the knee. In high-grade OCD lesions, free osteochondral fragments usually are refixed via titanium screws or biodegradable screws or pins. In this case, headless compression screws made from magnesium were used for refixation.

CASE REPORT

A thirteen-year-old female patient with a two-year history of knee pain was diagnosed with an OCD lesion of the medial femoral condyle. After initial conservative treatment, displacement of the osteochondral fragment occurred. Refixation was performed using two headless magnesium compression screws. At the 6 months follow up, the patient was pain free, and the fragment showed progressive healing while the implants were biodegrading.

DISCUSSION

Existing implants for refixation of OCD lesions either require subsequent removal or show less stability and possible inflammatory reactions. The new generation of magnesium screws used in this case did not lead to a gas release, as described for previous magnesium implants, while maintaining stability during continuous biodegradation.

CONCLUSIONS

The data available to date on magnesium implants for the treatment of OCD are promising. However, the evidence on the magnesium implants in refixation surgery of OCD lesions is still limited. Further research needs to be conducted to provide data on outcomes and possible complications.

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.

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.

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.

Evidence-based Risk Stratification for Sport Medicine Procedures During the COVID-19 Pandemic

Orthopaedic practices have been markedly affected by the emergence of the COVID-19 pandemic. Despite the ban on elective procedures, it is impossible to define the medical urgency of a case solely on whether a case is on an elective surgery schedule. Orthopaedic surgical procedures should consider COVID-19-associated risks and an assimilation of all available disease dependent, disease independent, and logistical information that is tailored to each patient, institution, and region. Using an evidence-based risk stratification of clinical urgency, we provide a framework for prioritization of orthopaedic sport medicine procedures that encompasses such factors. This can be used to facilitate the risk-benefit assessment of the timing and setting of a procedure during the COVID-19 pandemic.

Scaffold-Mediated Gene Delivery for Osteochondral Repair

Osteochondral defects involve both the articular cartilage and the underlying subchondral bone. If left untreated, they may lead to osteoarthritis. Advanced biomaterial-guided delivery of gene vectors has recently emerged as an attractive therapeutic concept for osteochondral repair. The goal of this review is to provide an overview of the variety of biomaterials employed as nonviral or viral gene carriers for osteochondral repair approaches both in vitro and in vivo, including hydrogels, solid scaffolds, and hybrid materials. The data show that a site-specific delivery of therapeutic gene vectors in the context of acellular or cellular strategies allows for a spatial and temporal control of osteochondral neotissue composition in vitro. In vivo, implantation of acellular hydrogels loaded with nonviral or viral vectors has been reported to significantly improve osteochondral repair in translational defect models. These advances support the concept of scaffold-mediated gene delivery for osteochondral repair.

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.

Small-Diameter Subchondral Drilling Improves DNA and Proteoglycan Content of the Cartilaginous Repair Tissue in a Large Animal Model of a Full-Thickness Chondral Defect

This study quantified changes in the DNA content and extracellular matrix composition of both the cartilaginous repair tissue and the adjacent cartilage in a large animal model of a chondral defect treated by subchondral drilling. Content of DNA, proteoglycans, and Type II and Type I collagen, as well as their different ratios were assessed at 6 months in vivo after treatment of full-thickness cartilage defects in the femoral trochlea of adult sheep with six subchondral drill holes, each of either 1.0 mm or 1.8 mm in diameter by biochemical analyses of the repair tissue and the adjacent cartilage and compared with the original cartilage. Only subchondral drilling which were 1.0 mm in diameter significantly increased both DNA and proteoglycan content of the repair tissue compared to the original cartilage. DNA content correlated with the proteoglycan and Type II collagen content within the repair tissue. Significantly higher amounts of Type I collagen within the repair tissue and significantly increased DNA, proteoglycan, and Type I collagen content in the adjacent cartilage were identified. These translational data support the use of small-diameter bone-cutting devices for marrow stimulation. Signs of early degeneration were present within the cartilaginous repair tissue and the adjacent cartilage.