Fixation of unstable osteochondritis dissecans lesions of the knee using arthroscopic autogenous osteochondral grafting (mosaicplasty)

A systematic review of cartilage procedures for unstable osteochondritis dissecans

OBJECTIVES

Osteochondritis dissecans can result in significant limitations in activity, pain, and early osteoarthritis. There are various treatment modalities to address these defects. The purpose of this study was to provide a qualitative summary of the various treatment options for unstable osteochondritis dissecans in the knee.

METHODS

A literature search was performed on osteochondritis dissecans in the knee using PubMed (MEDLINE), Embase, and Cochrane electronic databases. The search was completed using a combination of the following terms: 'osteochondritis dissecans,' 'OCD,' 'osteochondral,' 'articular cartilage,' 'repair,' 'surgery,' 'treatment,' 'osteochondral allograft,' 'autologous chondrocyte implantation,' 'unstable,' 'knee,' 'clinical studies.'

RESULTS

A total of 682 studies were found, of which 24 were included in the qualitative analysis. The quality score ranged from 46 to 80, and the mean follow-up ranged from 2 to 17 years. The most common surgical procedures were internal fixation (n = 7 studies), ACI (n = 6), fragment excision (n = 3), MACI (n = 2), bone graft + ACI (n = 2), OCA (n = 2), mosaicplasty/OAT (n = 2), and scaffold (n = 2). Overall, the reported outcome measures were heterogeneous in nature. Post-operative International Knee Documentations Committee (IKDC) scores ranged from 75 to 85 and Lysholm scores ranged from 70 to 93.5. Tegner scores ranged from 4 to 5. Rates of failure, complication, and revision were highly variable across studies and surgical techniques.

CONCLUSION

There are a variety of surgical options for the treatment of unstable osteochondritis dissecans. In skeletally immature patients, internal fixation demonstrated acceptable rates of radiographic union and patient reported outcome measures. In skeletally mature patients with large lesions, MACI and OCA transplantation provided similar patient reported outcomes.

An update on osteochondritis dissecans of the knee

Osteochondritis dissecans of the knee (OCD) is a multifactorial pathology in where repetitive microtrauma plays a central role in the etiopathogenesis. Knee MRI is indicated in young, active patients who have knee pain and/or effusion, to make an early diagnosis and decide about treatment, according essentially to the MRI stability signs. The choice of treatment should be also tailored, based on the patient's skeletal maturity, as well as the size and location of the lesion. Conservative treatment with restricting sports activities is the first line treatment and often sufficient to ensure healing in patients with open physes. Surgical treatment depends on the persistence of symptoms after 6 months of conservative treatment and/or based on the development of signs of instability of the lesion. Stable lesions with intact articular cartilage may be treated by drilling of the subchondral bone aiming to stimulate vascular ingrowth and subchondral bone healing. Every attempt should be made to retain the osteochondral fragment when possible. Instable lesions should be fixed or "replaced" with salvage procedures to prevent the onset of early osteoarthritis in this young population. Furthers studies are needed to improve the knowledge and optimizing non-operative and surgical treatment and to develop noninvasive diagnostic tools to predict with more accuracy the fragment's stability.

Fixation of an Osteochondral Lesion of the Femoral Intercondylar Groove Using Autogenous Osteochondral Grafts and Bioabsorbable Pins in a Patient with Open Physes: A Case Report

Osteochondral lesion (OCL) of the patellofemoral (PF) joint is not an uncommon cause of knee pain, and surgery is needed when conservative treatment fails. However, there is a lack of evidence regarding the optimal surgical treatment for OCL of the PF joint. Fixation of OCLs using autogenous osteochondral grafts has been reported to be effective for OCL of the knee. However, in this surgical technique, the biomechanical strength of osteochondral grafts may not be sufficient in patients with open physes due to the specific quality of the cartilage and subchondral bone given their age. There is a lack of studies reporting fixation of the OCL located in the PF joint using autogenous osteochondral grafts. We herein report a case of OCL of the femoral intercondylar groove where autogenous osteochondral grafts augmented with bioabsorbable pins were used to fix the lesion in a 14-year-old patient with open physes. Preoperative MRI revealed a completely detached OCL of the intercondylar groove (36 mm × 20 mm). Although a total of four osteochondral grafts were harvested from the non-weightbearing area of the lateral femoral condyle, cartilage detached from one of the grafts. The quality of the osteochondral grafts was considered to be insufficient for stabilization of the OCL; thus, two bioabsorbable pins were additionally inserted following fixation of the lesion using three osteochondral grafts. After two years of follow-up, postoperative functional scores were favorable without knee pain. The present case suggests that fixation of the OCL using autogenous osteochondral grafts may not be appropriate for young patients with open physes.

Autologous osteochondral transplantation for focal femoral condyle defects: Comparison of mosaicplasty by arthrotomy vs. arthroscopy

BACKGROUND

While many studies have reported the outcomes of open mosaicplasty, data on arthroscopic mosaicplasty are scarce. Only two cadaver studies have compared arthrotomy and arthroscopy. Moreover, the patello-femoral joint, which is the main donor site, has never been assessed using a specific functional score. The objective of this in vivo study was to compare arthrotomy and arthroscopy for mosaicplasty using both a global functional knee score and a specific score of the patello-femoral joint.

HYPOTHESIS

The arthroscopic technique results in better functional patello-femoral outcomes.

MATERIAL AND METHODS

We retrospectively compared two groups of 17 patients who underwent mosaicplasty for focal condylar cartilage defects, at our department between 2009 and 2019. Functional outcomes were assessed using the Kujala score and the Lysholm score, at least 1 year after surgery. The return to sports was assessed using the Tegner score.

RESULTS

Mean follow-up was 67.4±15.9 months in the arthrotomy group and 45.2±35.1 months in the arthroscopy group (p<0.01). Cartilage defect size was similar in the two groups (arthrotomy: 1.21±0.91cm²; arthroscopy: 0.92±1.23cm²; p=0.052). The mean Kujala score was 85±21.3 in the arthrotomy group and 91.9±13.7 in the arthroscopy group (p=0.064). The mean Lysholm score was 83.9±19.8 with arthrotomy and 89.5±14.9 with arthroscopy (p=0.1). The Kujala score was greater than 95 in 4 (26%) arthrotomy patients and 13 (81%) arthroscopy patients (p=0.003). The Lysholm score was higher than 95 in 4 (26%) arthrotomy patients and 12 (75%) arthroscopy patients (p=0.012). No patient underwent surgical revision for autograft failure.

DISCUSSION

This is the first clinical study comparing arthrotomy and arthroscopy for mosaicplasty. Clinical outcomes were good with both techniques. The proportion of patients with excellent Lysholm and Kujala functional scores was significantly higher in the arthroscopy group than in the arthrotomy group. This result may be ascribable to decreased donor-site morbidity obtained with arthroscopy.

LEVEL OF EVIDENCE

IV, retrospective observational comparative study.

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.

Treatment of knee osteochondritis dissecans with autologous tendon transplantation: Clinical and radiological results

BACKGROUND

Defect treatment with tendon autograft in osteochondral lesions has been published in the literature with an experimental study in dogs. To demonstrate that it is possible to treat knee osteochondral lesions with the technique of autologous tendon transplantation.

AIM

To evaluate the clinical and radiological results of patients with knee osteochondral lesions who were treated with autologous tendon transplantation.

METHODS

Twenty patients (22 knees) with osteochondritis dissecans (OCD) lesions involving the knee were treated with autologous tendon transplantation between 2005-2018. All lesions were International Cartilage Repair Society grade IV. All patients were evaluated clinically at final follow-up with knee injury and osteoarthritis outcome score (KOOS); and radiologically with magnetic resonance observation and cartilage repair tissue (MOCART) and Kellgren-Lawrence (KL) classification.

RESULTS

A total of 20 patients (22 knees) with a mean age of 25.5± 6.8 years were included. The average defect size was 4.2 ± 2.1 cm², and the average defect depth was 0.9 ± 0.4 cm. Total KOOS score was preoperatively 29.4 ± 5.5 and was later found to be 81.5 ± 5.9 after an average of 68.7 ± 37.7 mo follow-up. The mean MOCART score was 56.2 ± 10.7. Preoperatively, all of the patients had KL grades of 0–1; during the follow-up period, 80% of the patients showed no radiological progress of osteoarthritis. Patients with less than 4 cm² lesion had statistically significantly better overall KOOS than patients whose more than 4 cm² lesion, particularly in sport and quality of life subscales.

CONCLUSION

The autologous tendon transplantation is a single-step, safe, simple, cost-effective method for the treatment of knee OCD with satisfactory clinical and radiological outcomes, particularly in patients with less than 4 cm² lesion.

Fresh Osteochondral Allograft Transplantation in Osteochondritis Dissecans in the Knee Joint

Osteochondritis dissecans (OCD) is a chronic and painful joint condition that can occur from childhood through to adult life. Microtrauma, vascular insufficiency, or abnormal endochondral ossification are the most common causes of OCD. Reconstructive techniques for OCD of the knee are typically necessary when either non-operative or reparative/regenerative operative treatments fail, or when the OCD is irreversible. To analyze the clinical outcomes and failure rates of fresh osteochondral allograft transplantation (FOCA) used as a reconstructive strategy in OCD patients, an in-depth search was carried out on the PubMed, Scopus, and Web of Science databases concerning the existing evidence related to the use of FOCA for OCD patients in the knee joint. A total of 646 studies were found through the search and 2 studies were added after a cross-referenced examination of the articles within the bibliography. Six studies with a total of 303 OCD lesions treated with FOCA, with a mean follow-up of 6.3 years, were included. Although a limited number of low-level evidence studies on this topic are available in previous research, satisfactory clinical results and survival rates of the reconstruction are reported. However, to better define the real advantages of FOCA in the healing process of OCD lesions, comparative studies with different techniques are needed.

Osteochondral Peg Fixation for Chondral Fragment of the Knee in Adolescent Patients: A Report of Two Cases

INTRODUCTION

Purely chondral injuries of the knee are relatively rare, and no consensus exists on the appropriate treatment in such cases. We describe two adolescent patients with chondral injury of the knee who were successfully treated by osteochondral peg fixation. Patients, Concerns, and Clinical Findings. In case 1, a 14-year-old boy presented with complaints of right knee pain after landing on his leg while playing basketball. Radiography and computerized tomography revealed no abnormalities. However, magnetic resonance imaging revealed a chondral defect in his lateral femoral condyle and a loose chondral fragment measuring 6.5 cm2. In case 2, a 12-year-old boy presented with complaints of left knee pain after a rotational injury while playing baseball. Similar to case 1, magnetic resonance imaging revealed a chondral defect in his lateral femoral condyle and a loose chondral fragment measuring 3.0 cm2. Primary Diagnosis, Interventions, and Outcomes. The two patients were treated by surgical fixation using osteochondral pegs, which were harvested from the femoral condyle. After a year, postoperative computerized tomography and magnetic resonance imaging showed union of the chondral fragment with the osteochondral pegs and surrounding tissue. In both cases, the Lysholm score was 100 points at the final follow-up more than 2 years after surgery.

CONCLUSION

The findings reported herein suggest that osteochondral peg fixation is a feasible treatment option for chondral injury of the knee, with satisfactory outcomes.

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.

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.

Contralateral Lateral Femoral Condyle Allografts Provide an Acceptable Surface Match for Simulated Classic Osteochondritis Dissecans Lesions of the Medial Femoral Condyle

Background:

Osteochondral allograft transplantation is an effective technique for repairing large lesions of the medial femoral condyle (MFC), but its use is limited by graft availability.

Purpose/Hypothesis:

The present study aimed to determine whether contralateral lateral femoral condyle (LFC) allografts can provide an acceptable surface match for posterolateral MFC lesions characteristic of classic osteochondritis dissecans (OCD). The hypothesis was that LFC and MFC allografts will provide similar surface contour matches in all 4 quadrants of the graft for posterolateral MFC lesions characteristic of OCD.

Study Design:

Controlled laboratory study.

Methods:

Ten fresh-frozen recipient human MFCs were each size-matched to 1 ipsilateral medial and 1 contralateral LFC donor (N = 30 condyles). After a nano–computed tomography (nano-CT) scan of the native recipient condyle, a 20-mm circular osteochondral “defect” was created 1 cm posterior and 1 cm medial to the roof of the intercondylar notch (n = 10). A size-matched, random-order donor MFC or LFC plug was then harvested, transplanted, and scanned with nano-CT. Nano-CT scans were then reconstructed, registered to the initial scan of the recipient MFC, and processed in MATLAB to determine the height deviation (d_RMS) between the native and donor surfaces and percentage area unacceptably (>1 mm) proud (%A_proud) and sunken (%A_sunk). Circumferential step-off height (h_RMS) and percentage circumference unacceptably (>1 mm) proud (%C_proud) and sunken (%C_sunk) were measured using DragonFly software. The process was then repeated for the other allograft plug.

Results:

Both MFC and LFC plugs showed acceptable step-off heights in all 4 quadrants (range, 0.53-0.94 mm). Neither allograft type nor location within the defect had a significant effect on step-off height (h_RMS), surface deviation (d_RMS), %A_proud, or %A_sunk. In general, plugs were more unacceptably sunken than proud (MFC, 13.4% vs 2.4%; LFC, 13.2% vs 8.1%), although no significant differences in %C_sunk were seen between allograft types or locations within the defect. In LFC plugs, %C_proud in the lateral quadrant (28.0% ± 26.1%) was significantly greater compared with all other quadrants (P = .0002).

Conclusion:

The present study demonstrates that 20-mm contralateral LFC allografts provide an acceptable surface match for posterolateral MFC lesions characteristic of OCD.

Clinical Relevance:

With comparable surface matching, MFC and LFC allografts can be expected to present similar stresses on the knee joint and achieve predictably positive clinical outcomes, thus improving donor availability and reducing surgical wait times for matches.

Treatment of unstable knee osteochondritis dissecans in the young adult: results and limitations of surgical strategies-The advantages of allografts to address an osteochondral challenge

Joint surface incongruence resulting from osteochondritis dissecans (OCD) alters the articular physiologic congruence, increasing the contact stress on adjacent joint surfaces and accelerating wear and the cascade of joint degeneration. Accordingly, the restoration of articular surface integrity is of major importance, especially in young adults where, in lesions left untreated or following simple fragment excision, early osteoarthritis can be anticipated. Therefore, the treatment algorithm in unstable knee OCD of the young adult foresees surgical options to restore the articular surface. Several procedures have been proposed, including refixation of the detached fragment bone marrow stimulation, osteochondral autograft implantation, fresh osteochondral allograft transplantation, and cell-based or cell-free regenerative techniques. The aim of this review was to summarize the evidence for these surgical strategies, reporting their results and limitations. The overall evidence documents positive results for each of the assorted surgical procedures applied to treat unstable OCD, thus indicating support for their selected use to treat osteochondral defects paying particular attention to their specific indications for the lesion characteristics. The fixation of a good quality fragment should be pursued as a first option, while unfixable small lesions may benefit from autografts. For large lesions, available cell-based or cell-free osteochondral scaffold are a feasible solution but with limitation in terms of regenerated tissue quality. In this light, fresh allografts may offer articular surface restoration with viable physiologic osteochondral tissue providing a predictably successful outcome, and therefore they may currently represent the most suitable option to treat unstable irreparable OCD lesion in young adults. LEVEL OF EVIDENCE: V.

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

This article is a review of the current understanding of the etiology, pathogenesis, and how to diagnose and treat knee osteochondritis dissecans (OCD) followed by an analysis of and outcomes of the treatments available. OCD is seen in children and adolescents with open growth plates (juvenile OCD) and adults with closed growth plates (adult OCD). The etiology of OCD lesions remains unclear and is characterized by an aseptic necrosis in the subchondral bone area. Mechanical factors seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important. Regarding treatment, a tremendous number of publications exist. Spontaneous healing is expected unless there is an unstable fragment, and treatment involves rest and different degrees of immobilization until healing. Patients with open physes and low-grade lesions have good results with conservative therapy. When surgery is necessary, the procedure depends on the stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable. When the cartilage is damaged, several techniques can be used. While techniques such as drilling and microfracturing produce reparative cartilage, other techniques reconstruct the defect with additional osteochondral grafts or cell-based procedures such as chondrocyte transplantation. There is a tendency toward better results when using procedures that reconstruct the bone and the cartilage and there is also a trend toward better long-term results when comorbidities are treated. Severe grades of osteoarthrosis are rare.

Orthopedic Surgical Options for Joint Cartilage Repair and Restoration

The limited natural capacity for articular cartilage to regenerate has led to a continuously broadening array of surgical interventions. Used once patients' symptoms are not relieved by nonoperative management, these share the goals of joint preservation and restoration. Techniques include bone marrow stimulation, whole-tissue transplantation, and cell-based strategies, each with its own variations. Many of these interventions are performed arthroscopically or with extended-portal techniques. Indications, operative techniques, unique benefits, and limitations are presented.

Osteochondral Allograft Transplantation in Patients With Osteochondritis Dissecans of the Knee

BACKGROUND

Osteochondritis dissecans (OCD) of the knee can be difficult to treat. Cartilage restoration techniques are often indicated when the lesion or fragment cannot be salvaged and the patient remains symptomatic. Fresh osteochondral allograft (OCA) transplantation can restore both bone and cartilage defects characteristic of OCD.

HYPOTHESIS

We hypothesized that osteochondral allografting is a successful method for treating OCD of the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study comprised 135 patients (149 knees) who underwent OCA for OCD of the knee (type III or IV) between 1997 and 2013 and had a minimum follow-up of 2 years. The median age was 21 years (range, 12-55 years) and 75.8% of the patients were male. The mean allograft size was 7.3 cm² (range, 2.2-25 cm²). Evaluation included the following: frequency and type of reoperations; modified Merle d'Aubigné and Postel (18-point) scale; International Knee Documentation Committee (IKDC) pain, function, and total scores; and Knee Society function (KS-F) and knee (KS-K) scores. Clinical failure was defined as revision OCA or conversion to arthroplasty. Graft survivorship was determined.

RESULTS

The median follow-up time was 6.3 years (range, 1.9-16.8 years) and 62% of participants had more than 5-year follow-up. Thirty-four of 149 knees (23%) had reoperations, of which 12 (8%) were classified as allograft failures (7 OCA revisions, 3 unicompartmental knee arthroplasties, and 2 total knee arthroplasties). OCA survivorship was 95% at 5 years and 93% at 10 years. Of the 137 knees whose grafts were still in situ at the latest follow-up, the mean modified Merle d'Aubigné and Postel (18-point) score was 16.8; IKDC pain, function, and total scores were 2.1, 8.1, and 82.3; and KS-F and KS-K scores were 95.7 and 94.3, respectively. The majority of patients (95%) reported being satisfied with the outcome of their procedure.

CONCLUSION

OCA transplantation was an effective treatment for OCD of the knee, with a low rate of graft failure, significant improvement in pain and function scores, and high patient satisfaction.

Osteochondritis dissecans of the knee

Osteochondritis Dissecans (OCD) is a condition for which the aetiology remains unknown. It affects subchondral bone and secondarily its overlying cartilage and is mostly found in the knee. It can occur in adults, but is generally identified when growth remains, when it is referred to as juvenile OCD. As the condition progresses, the affected subchondral bone separates from adjacent healthy bone, and can lead to demarcation and separation of its associated articular cartilage. Any symptoms which arise relate to the stage of the disease. Early disease without separation of the lesion results in pain. Separation of the lesion leads to mechanical symptoms and swelling and, in advanced cases, the formation of loose bodies.

Early identification of OCD is essential as untreated OCD can lead to the premature degeneration of the joint, whereas appropriate treatment can halt the disease process and lead to healing. Establishing the stability of the lesion is a key part of providing the correct treatment. Stable lesions, particularly in juvenile patients, have greater propensity to heal with non-surgical treatment, whereas unstable or displaced lesions usually require surgical management.

This article discusses the aetiology, clinical presentation and prognosis of OCD in the knee. It presents an algorithm for treatment, which aims to promote healing of native hyaline cartilage and to ensure joint congruity.

Take home message: Although there is no clear consensus as to the best treatment of OCD, every attempt should be made to retain the osteochondral fragment when possible as, with a careful surgical technique, there is potential for healing even in chronic lesions

Cite this article: Bone Joint J 2016;98-B:723–9.

Treatment of unstable osteochondritis dissecans in adults with autogenous osteochondral grafts (Mosaicplasty): long-term results

PURPOSE

the unstable osteochondritis dissecans (OCD-type II and III according to the ICRS classification) of the knee largher than > 2.5 cm(2) in adults are uncommon lesions and there is no consensus on how to treat them. Medium-term studies have reported good results using autogenous osteochondral plugs (mosaicplasty). The aim of this study is to analyze the long-term results of this technique for the treatment of unstable OCD in a selected group of adult patients.

METHODS

four patients with OCD at either one of the femoral condyles were included in this prospective study. The average age was 21.2 years (range, 18-24 years). The OCD lesions were classified as type II in three patients and type III in one patient and the average size was 3.8 cm(2) (range, 2.55-5.1 cm(2)). The lesions were treated in situ with a variable number of autogenous osteochondral plugs (Ø 4.5 mm(2)). The Modified Cincinnati, Lysholm II and Tegner scores were used for clinical and functional evaluation. Magnetic resonance arthrography (MRA) was performed before surgery and at 2, 5 and 10 years after surgery. A modified MOCART score was used to evaluate MRA findings.

RESULTS

the average follow-up duration was ten years and 6 months (range, 10-11 years). No complications occurred. At the final follow-up, all scores (clinical, functional and MOCART) improved. In all but one of the patients MRA showed complete osteochondral repair.

CONCLUSIONS

the fixation of large and unstable OCD lesions with mosaicplasty may be a good option for treating type II or III OCD lesions in adults. The advantages of this technique include stable fixation, promotion of blood supply to the base of the OCD fragment, and grafting of autologous cancellous bone that stimulates healing with preservation of the articular surface.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Juvenile osteochondritis dissecans in the lateral femoral condyle requiring osteochondral autograft as a revision procedure: a case report

Background

The optimal treatment option for osteochondritis dissecans of the knee is still controversial. We report the case of a boy who developed osteochondritis dissecans in the lateral femoral condyles of his bilateral knees requiring repeat surgical procedures. There has been no literature reporting juvenile osteochondritis dissecans of bilateral knees requiring repeat surgical procedures.

Case presentation

A 6-year-old Japanese boy presented with pain in his bilateral knees. Although conservative treatment with prohibition of sports activities was continued for 6 months, healing could not be attained. Conservative treatment consisting of prohibition of sports activities that included running and jumping and use of a brace with a locking mechanism at full extension was applied. He was instructed to walk with the brace. Since his lateral femoral osteochondritis dissecans lesion was located at the contact area during flexion, weight bearing with the use of the brace could effectively unload the lesion. Surgery was subsequently conducted on his left knee which had a more advanced stage lesion. Transchondral drilling was performed because the articular surface maintained its smooth continuity. At 9 months after the surgery, no appreciable healing was observed in the follow-up radiographs. Moreover, during the postoperative time course, lesions suggestive of osteochondritis dissecans in his contralateral right knee had become more evident. Based on the diagnosis of delayed union of bilateral osteochondritis dissecans lesions, a second surgery was attempted. The preceding arthroscopic observation of his left knee showed preserved surface continuity with softening and suspected partial detachment. Considering the delayed healing process observed in this patient, autogenous cylindrical osteochondral graft transplantation (8 mm in diameter) was performed as a revision procedure, while transchondral drilling was performed for the stable osteochondritis dissecans lesion in his right knee. Postoperatively, healing was achieved at 6 months.

Conclusions

Following failed conservative treatment, he underwent arthroscopic drilling; however, the osteochondritis dissecans lesion did not heal requiring revision surgery using a cylindrical autogenous osteochondral graft. Finally, clinical and radiological healing was attained 6 months after the second surgery. Initial presentation at a young age with bilateral lesions may be clinical factors related to poor healing response and susceptibility to stress-related subchondral lesions.

Functional and radiographic outcomes of unstable juvenile osteochondritis dissecans of the knee treated with lesion fixation using bioabsorbable pins

BACKGROUND

The purpose of this study was to evaluate the functional and radiographic outcome of fixation of unstable juvenile osteochondritis dissecans lesions of the knee after a minimum of 2 years of follow-up.

METHODS

A total of 33 unstable juvenile osteochondritis dissecans lesions in 30 patients underwent fixation using bioabsorbable pins through arthrotomy or under arthroscopy. The patients consisted of 23 males and 7 females, and the average age at the time of operation was 14.4 years (range, 11 to 17 y). The functional outcomes were evaluated using the Lysholm score and Hughston's criteria at a mean follow-up of 3.3 years (range, 2.1 to 6.3 y). Healing of the osteochondritis dissecans lesions were confirmed by plain radiographs and magnetic resonance imaging.

RESULTS

The Lysholm score improved significantly at 3 months after the surgery, and was maintained until the final follow-up. Radiographically, 32 of 33 lesions healed after fixation of the lesion (healing rate was 97.0%). Healing was achieved at an average of 2.4 months on plain radiographs and 4.2 months on magnetic resonance imaging. According to Hughston's criteria, 25 patients were graded as excellent, 4 as good, and 1 as poor at the final follow-up.

CONCLUSIONS

The fixation of the unstable juvenile osteochondritis dissecans lesions with bioabsorbable pins demonstrated improved clinical outcomes and radiographic high healing rates at a mean of 3.3 years of follow-up. We advocate this procedure for patients with unstable juvenile osteochondritis dissecans lesions of sufficient quality to enable fixation which will preserve the normal contour of the distal femur.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Management strategies for osteochondritis dissecans of the knee in the skeletally immature athlete

SYNOPSIS

Osteochondritis dissecans (OCD) is a disorder resulting in focal breakdown of the subchondral bone, with potential disruption of the overlying articular cartilage. The femoral condyles of the knee are the most common locations for OCD, and the incidence of OCD appears to be increasing among active children. Juvenile OCD (JOCD) can be distinguished from adult OCD by the presence of open growth plates. Due to a lack of evidence on its early diagnosis, optimal treatment, and long-term course of healing, JOCD presents a unique challenge for the health care team. Approximately 50% to 67% of stable JOCD lesions heal successfully with nonoperative treatment. For unstable lesions and stable lesions that fail nonoperative treatment, a variety of surgical interventions can be utilized to stimulate bony healing and address articular cartilage lesions. It is recommended that rehabilitation of JOCD be tailored to the individual patient, based on the stage and radiographic status of the lesion and the mode of surgery employed when surgically addressed. Although there is a growing body of literature on this condition, the etiology and optimal methods for treatment, rehabilitation, and evaluating outcomes remain inconclusive due to a lack of quality evidence.

LEVEL OF EVIDENCE

Therapy, level 5.

Autologous osteochondral transplantation for treating patellar chondral injuries: evaluation, treatment, and outcomes of a two-year follow-up study

BACKGROUND

The patella is the largest human sesamoid bone and often sustains chondral injury. There is no consensus on how to treat a full-thickness, symptomatic articular cartilage injury of the patella. We analyzed the clinical and functional outcomes of patients with symptomatic full-thickness patellar chondral lesions treated with autologous osteochondral transplantation and evaluated osteochondral autograft bone-plug integration through magnetic resonance imaging.

METHODS

In this prospective study, thirty-three patients with a symptomatic full-thickness patellar chondral injury surgically treated with autologous osteochondral transplantation were evaluated before and after surgical treatment with a minimum two-year follow-up using the Lysholm, Kujala, and Fulkerson questionnaires and the Short Form-36 health survey score. Magnetic resonance images were made at six and twelve months postoperatively and studies were performed to analyze the osteochondral autograft bone-plug integration.

RESULTS

All thirty-three patients showed a significant improvement in functional scores two years after surgery. The average Lysholm scores were 57.27 points preoperatively and 80.76 points at two years postoperatively, the average Kujala scores were 54.76 points preoperatively and 75.18 points at two years postoperatively, and the Fulkerson average scores were 54.24 points preoperatively and 80.42 points at two years postoperatively. The Short Form-36 life quality score improved significantly. Two years after surgery, all magnetic resonance images showed full bone-plug integration into the patella.

CONCLUSIONS

Autologous osteochondral transplantation is a successful technique to surgically treat symptomatic full-thickness patellar articular cartilage injuries smaller than 2.5 cm in diameter. Patients had a significant improvement in clinical scores. Bone-plug integration and surface alignment were demonstrated in all patients two years after surgery.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The pediatric knee: current concepts in sports medicine

As the popularity and intensity of children's athletics have increased, so has the risk for knee injuries. Fractures of the tibial eminence may be treated operatively or nonoperatively depending on fracture classification, but arthrofibrosis is a potentially significant complication. Anterior cruciate ligament rupture presents treatment challenges as regards the optimal timing and method of reconstruction. A number of novel reconstructive techniques have been developed to minimize risks to the physes in this population. Recent studies have focused on the prognosis, surgical indications, and operative techniques for osteochondritis dissecans in children. A number of authors have also sought to better-define the optimal diagnostic testing and management of patellar dislocation. In this review, we provide an update on current concepts for tibial eminence fractures, anterior cruciate ligament injuries, osteochondritis dissecans of the knee, and patellar dislocation in young athletes.

Allogenous bone with collagen for repair of deep osteochondral defects

BACKGROUND

A scaffold for treatment of deep osteochondral defects should be stable, integrate well, and provide a surface for chondrocytes. To meet these demands, a biphasic scaffold of allogenous sterilized bone with a collagen surface was developed. Integration was tested in the sheep model.

MATERIAL AND METHODS

Cartilage chips were taken from the nonweight-bearing area of the left knee of 12 sheep and cultured. After 4 wk a second procedure followed and defects of 9.4-mm diameter at the weight-bearing area of the medial femoral condyle of the right knee were created. The sterilized scaffold was inserted and the cultured autologous chondrocytes were dripped onto the surface. After 6 wk, 3 mo, and 6 mo the animals were sacrificed; the explanted femoral condyles were evaluated macroscopically and using histologic, immunohistochemical, and electronmicroscopic methods.

RESULTS

After 6 wk the level of the surface was well preserved, after 3 mo parts of the scaffold were sintered but after 6 mo the surface was continuous. Full integration of the allogenous bone could be observed after 6 mo. The surface of the scaffold after 6 wk consisted of bone, but after 3 mo some chondrocytes and after 6 mo a continuous chondral layer could be detected.

CONCLUSIONS

The biphasic scaffold of allogenous bone and collagen proved to be stable and sufficiently integrated in the short- and midterm interval. Whether the chondrocytes on the surface had been derived from implanted chondrocytes or the scaffold with its surface was sufficiently chondroconductive must be answered in further investigations.

Surgical management of osteochondritis dissecans of the knee

Osteochondritis dissecans of the knee primarily affects subchondral bone, with a secondary effect on the overlying articular cartilage. This process can lead to pain, effusions, and loose body formation. While stable juvenile lesions often respond well to nonoperative management, unstable juvenile lesions, as well as symptomatic adult lesions, often require operative intervention. Short-term goals focus on symptomatic relief, while long-term expectations include the hope of preventing early-onset arthritis. Surgical options include debridement, loose body removal, microfracture, arthroscopic reduction and internal fixation, subchondral drilling, osteochondral autograft or allograft transplantation, and autologous chondrocyte implantation. Newer single-stage cell-based procedures have also been developed, utilizing mesenchymal stem cells and matrix augmentation. Proper treatment requires evaluation of both lesional (size, depth, stability) and patient (age, athletic level) characteristics.

A review of knowledge in osteochondritis dissecans: 123 years of minimal evolution from König to the ROCK study group

BACKGROUND

Osteochondritis dissecans (OCD) was first described to provide an explanation for the nontraumatic development of loose bodies within a joint. Despite many reports on the subject, there remains no clear understanding of the etiology, natural history, or treatment.

QUESTIONS/PURPOSES

This review was undertaken to delineate (1) the etiology of OCD; (2) the presentation and locations; (3) the most appropriate imaging modalities; and (4) the most effective treatment strategies.

METHODS

We reviewed the English literature using a database compiled from a Medline search for "osteochondritis dissecans". We identified 1716 publications, 1246 of which were in English. After exclusions, we reviewed 748 articles and of these cited 85. The observations of each study were then synthesized into this report.

RESULTS

There appears to be no consensus concerning the etiology of OCD lesions. The presentations and locations are variable, but the knee, ankle, and elbow are most commonly involved. Although plain film assessment is important in OCD, there appears to be a trend toward the use of MRI, but the preferred sequences are in evolution. We found no consensus on the treatment of these lesions, related in part to the lack of agreement of methods for assessing outcomes.

CONCLUSIONS

Despite more than a century of study, we have made little advancement in our understanding of OCD. A study group has been formed to address this issue and actively seeks to answer these unknown issues regarding OCD.

Can fresh osteochondral allografts restore function in juveniles with osteochondritis dissecans of the knee?

BACKGROUND

Failure of initial treatment for juvenile osteochondritis dissecans (OCD) may require further surgical intervention, including microfracture, autograft chondrocyte implantation, osteochondral autografting, and fresh osteochondral allografting. Although allografts and autografts will restore function in most adults, it is unclear whether fresh osteochondral allograft transplantations similarly restore function in skeletally immature patients who failed conventional treatment.

QUESTIONS/PURPOSES

Therefore, we determined function in (1) daily activity; (2) sports participation; and (3) healing (by imaging) in children with juvenile OCD who failed conventional therapy and underwent fresh osteochondral allograft transplantation.

METHODS

We retrospectively reviewed 11 children with OCD of the knee treated with a fresh stored osteochondral allograft between 2004 and 2009 (six males and five females). The average age of the children at the time of their allograft surgery was 15.2 years (range, 13-20 years). The clinical assessments included physical examination, radiography, MRI, and a modified Merle D'Aubigné-Postel score. The size of the allograft was an average of 5.11 cm(2). The minimum followup was 12 months (average, 24 months; range, 12-41 months).

RESULTS

All patients had returned to activities of daily living without difficulties at 6 months and returned to full sports activities between 9 and 12 months after surgery. The modified Merle D'Aubigné-Postel score improved from an average of 12.7 preoperatively to 16.3 at 24 months postoperatively. Followup radiographs at 2 years showed full graft incorporation and no demarcation between the host and graft bone.

CONCLUSIONS

Our observations suggested fresh osteochondral allografts restored short-term function in patients with juvenile OCD who failed standard treatments.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Osteochondritis dissecans of the knee in children and adolescents

PURPOSE OF REVIEW

Osteochondritis dissecans (OCD) of the knee is a well-described condition that can cause significant morbidity in children and adolescents; timely diagnosis is key to preventing compromise to the articular cartilage and maximizing opportunity to perform a restorative procedure. Juvenile OCD has a better prognosis than does adult OCD, with higher rates of spontaneous healing with conservative treatment. Still, there are certain indications for surgical restoration procedures. Controversies arise over when to decide surgical procedure and what is the best surgical treatment option in this young population.

RECENT FINDINGS

Some authors believe nonoperative management should be the first-line treatment for stable OCD lesions in children. The only consensus in regard to this modality is that, if a patient is truly asymptomatic or experiencing low-level symptoms, then the duration of nonoperative treatment should be at least 3-6 months before opting for operative treatment. In the case of failed nonsurgical management or in the setting of an unstable fragment, surgical intervention should be implemented. Recent published data suggest no difference in clinical or radiographic outcome when comparing different surgical techniques.

SUMMARY

OCD of the knee requires a timely diagnosis to maximize opportunity to perform a reparative procedure. Indications for surgical treatment are based on lesion stability, skeletal maturity, and clinical symptoms. Reestablishing the joint surface, improving the blood supply of the fragment, rigid fixation, and early motion are primary goals for osteochondral fragment preservation. When the fragment is not suitable for preservation, careful consideration of defect location and the patient's clinical presentation will determine when cartilage restoration procedures should be utilized.

Biphasic scaffolds for repair of deep osteochondral defects in a sheep model

BACKGROUND

To oppose the disadvantages of autologous osteochondral transplantation in the treatment of deep osteochondral defects such as donor site morbidity, size limitation, and insufficient chondral integration, we developed two biphasic scaffolds of either hydroxylapatite/collagen (scaffold A) or allogenous sterilized bone/collagen (scaffold B) and tested their integration in a sheep model.

METHODS

We collected chondral biopsies from 12 sheep for the isolation of chondroblasts and cultured them for 4 wk. We created defects at the femoral condyle and implanted either scaffold A or B with chondrocytes or cell free. After 6 wk, animals were euthanized, we explanted the condyles, and evaluated them using histological, immunohistochemical, molecular biological, and histomorphometrical methods.

RESULTS

Specimens with scaffold A showed severe lowering of the surface, and the defect size was larger than for scaffold B. We found more immune-competent cells around scaffold A. Chondrocytes were scarcely detected on the surface of both scaffolds. Histomorphometry of the interface between scaffold and recipient showed no significant difference regarding tissue of chondral, osseous, fibrous or implant origin or tartrate-resistant acid phosphatase-positive cells. Real-time reverse transcriptase-polymerase chain reaction analysis revealed significant up-regulation for collagen II and SOX-9 messenger ribonucleic acid expression on the surface of scaffold B compared with scaffold A.

CONCLUSIONS

Scaffold B proved to be stable and sufficiently integrated in the short term compared with scaffold A. More extensive evaluations with scaffold B appear to be expedient.

Surgical management of juvenile osteochondritis dissecans of the knee

PURPOSE

Operative management of osteochondritis dissecans (OCD) in the juvenile knee is generally indicated upon failure of conservative treatment, in unstable lesions, and in lesions nearing physeal closure. We hypothesized that juvenile OCD lesions have improved clinical and radiographic outcomes with surgical treatment following failed non-surgical management, in unstable lesions, and in lesions nearing physeal closure.

METHODS

Multiple medical databases were searched for Levels I-IV evidence with specific study inclusion and exclusion criteria. Length of mean follow-up was minimum 2 years. Studies were included if an analysis of clinical outcomes following surgical treatment of juvenile OCD was performed. All surgical techniques and defect classifications were potentially inclusive.

RESULTS

Thirty studies (29 Level IV evidence) were included for analysis (783 subjects, 862 knees). Mean post-operative follow-up was 77 months. Nearly all studies within this review demonstrated significant clinical and radiographic improvements in outcomes in surgically treated juvenile OCD at short-, mid-, and long-term follow-up. Isolated excision of weight-bearing OCD lesions led to poorer clinical and radiographic results than other surgical techniques. Outcomes were significantly better with juvenile OCD versus adult OCD.

CONCLUSIONS

Surgical treatment of juvenile OCD has significantly improved clinical and radiographic outcomes at short-, mid-, and long-term follow-up. No difference in clinical or radiographic outcome was demonstrated in comparing different surgical techniques, with the exception of poorer results with isolated fragment excision.

LEVEL OF EVIDENCE

IV.

Human stem cells and articular cartilage regeneration

The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES) cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS) cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation.

Surgical treatment options for osteochondritis dissecans of the knee

Osteochondritis dissecans of the knee is identified with increasing frequency in the young adult patient. Left untreated, osteochondritis dissecans can lead to the development of osteoarthritis at an early age, resulting in progressive pain and disability. Treatment of osteochondritis dissecans may include nonoperative or operative intervention. Surgical treatment is indicated mainly by lesion stability, physeal closure, and clinical symptoms. Reestablishing the joint surface, maximizing the osteochondral biologic environment, achieving rigid fixation, and ensuring early motion are paramount to fragment preservation. In cases where the fragment is not amenable to preservation, the treatment may include complex reconstruction procedures, such as marrow stimulation, osteochondral autograft, fresh osteochondral allograft, and autologous chondrocyte implantation. Treatment goals include pain relief, restoration of function, and the prevention of secondary osteoarthritis.

OSTEOCHONDRITIS DISSECANS OF THE KNEE: DIAGNOSIS AND TREATMENT

Osteochondritis dissecans (OCD) is a pathological process affecting the subchondral bone of the knee in children and adolescents with open growth plates (juvenile OCD) and young adults with closed growth plates (adult OCD). It may lead to secondary effects on joint cartilage, such as pain, edema, possible formation of free bodies and mechanical symptoms, including joint locking. OCD may lead to degenerative changes may develop if left untreated. This article presents a review and update on this problem, with special emphasis on diagnosis and treatment. The latter may include either conservative methods, which show more predictable results for juvenile OCD, or various surgical methods, which include reparative techniques like isolated removal of the fragment, bone drilling and fixation of the osteochondral fragments, and restorative techniques like microfractures, autologous osteochondral transplantation (mosaicplasty), autologous chondrocyte implantation and fresh osteochondral allograft, depending on lesion stability, lesion viability, skeletal maturity and OCD process location. Recent assessments on the results from several types of treatment have shown that there is a lack of studies with reliable levels of evidence and have suggested that further multicenter prospective randomized and controlled studies on management of this disease should be conducted.

OSTEOCHONDRAL AUTOLOGOUS TRANSPLANTATION FOR TREATING CHONDRAL LESIONS IN THE PATELLA

Objective: The primary aim of this study was to assess the clinical and functional evolution of patients with total-thickness symptomatic cartilaginous injury of the patellar joint surface, treated by means of osteochondral autologous transplantation. Methods: This prospective study was conducted from June 2008 to March 2011 and involved 17 patients. The specific questionnaires of Lysholm, Kujala and Fulkerson were completed preoperatively and one year postoperatively in order to assess the affected knee, and SF-36 was used to assess these patients’ general quality of life. The nonparametric paired Wilcoxon test was used for statistical analysis on the pre and postoperative questionnaires. The data were analyzed using the SPSS for Windows software, version 16.0, and a significance level of 5% was used. Results: The Lysholm preoperative and postoperative average scores were 54.59 and 75.76 points (p < 0.05). The Fulkerson pre and postoperative average scores were 52.53 and 78.41 points (p < 0.05). Conclusions: We believe that autologous osteochondral transplantation is a good treatment method for total-thickness symptomatic chondral lesions of the joint surface of the patella.

Localization of vascular endothelial growth factor during the early stages of osteochondral regeneration using a bioabsorbable synthetic polymer scaffold

Vascular endothelial growth factor (VEGF) plays a critical role in chondrogenic differentiation in the growth plate of the epiphysis. This function is necessary for chondrocyte survival in cartilage development. We investigated the localization of VEGF in the osteochondral regeneration process using a bioabsorbable polymer scaffold. Osteochondral defects (5 mm in diameter and 5 mm in depth) were made on the femoral condyle of forty-eight skeletally mature female Japanese white rabbits. In total, twenty-four defects were filled with poly(DL-lactide-co-glycolide) scaffolds and the others were left untreated. The regeneration process was investigated macroscopically, histologically, immunohistochemically, and by gene expression analysis. In the early stages of osteochondral regeneration, bone ingrowth was observed in the deep zone of the scaffold with continuous VEGF expression; cartilage regeneration was observed in the superficial zone of the scaffold with decreased VEGF expression. In contrast, when the defect was left untreated, VEGF localization was observed throughout the entire defect area, and cartilage regeneration at the articular surface was delayed. We conclude that decrease in localization of VEGF at the articular surface in the postoperative early stage is closely related to the progression of cartilage regeneration in osteochondral defects.

Effectiveness and limitations of autologous osteochondral grafting for the treatment of articular cartilage defects in the knee

PURPOSE

To evaluate the effectiveness and limitations of autologous osteochondral grafting for the treatment of articular cartilage defects in the knee.

METHODS

The subjects were 40 patients who had undergone autologous osteochondral grafting. Fifteen knees had cartilage defects combined with anterior cruciate ligament tears (ACL group), 15 knees had cartilage defects combined with osteoarthritis (OA group), and 10 knees had cartilage defects combined with osteochondral dissecans (OCD group). From one to five osteochondral pegs were harvested from the less-weight-bearing periphery of the articular surface of the femoral condyle and grafted to cartilage defects. The clinical results were assessed based on the Lysholm score and radiographic and magnetic resonance imaging (MRI) image assessment.

RESULTS

The median follow-up duration was 24 months (range from 12 to 41 months). The mean Lysholm score following treatment was improved in all groups. The patients who had cartilage defects combined with OA had a significantly poorer prognosis than did those with cartilage defects combined with ACL or OCD. In the OA group, advanced stage and an alignment abnormality were correlated with poor prognosis. Advanced age was correlated with poor prognosis. Other parameters showed no significant difference in prognosis.

CONCLUSION

Autologous osteochondral grafting was found to be an effective technique for treating relatively young patients who had cartilage defects combined with ACL injury or OCD, but this technique showed limited results in treating cartilage defects based on advanced patient age and degenerative changes in the cartilage.

LEVEL OF EVIDENCE

Diagnostic studies-investigating a diagnostic test, Level III.

We do not have evidence based methods for the treatment of cartilage defects in the knee

PURPOSE

The aim of this study was to perform a systematic review of studies concerning current treatment of chondral defects of the knee.

METHODS

The relevance for evidence based data and for successful surgical treatment of cartilage defects was evaluated. From 56,098 evaluated studies, 133 studies could be further pursued. These supplied data concerning microfracturing, the osteochondral autograft transplantation system (OATS), the autologous chondrocyte implantation (ACI) and the matrix induced chondrocyte implantation (MACI). The modified Coleman Methodical Score (CMS) and the Level of Evidence (LOE) were applied to evaluate the quality.

RESULTS

In these studies, a total of 6,920 patients were reviewed with a median of 32 patients per study and a mean follow-up of 24 months. The mean CMS was 58 of 100 points. No study reached 100 points in the CMS. Three studies reached a level above 90. Ten studies were Level I, five studies reached Level II. Seven studies reached Level III, 111 studies Level IV. MRI scans to verify the clinical data were used by only 72 studies. The means in the modified CMS were for the different procedures as follows: ACI 58 points, MACI 57 points, microfracturing 68 points and OATS 50 points. 24 studies applied the Lysholm Score (LS) for clinical evaluation of cartilage surgery. All operative procedures yielded comparable improvements of the LS (n.s.) meaning that no operative procedure proved superior.

CONCLUSION

As the majority of studies evaluated by this review is insufficient for EBM purposes more coherent studies with LOE of I or II are needed. Co-relating the systems of CMS and LOE and validating the applied scores seems desirable.

Bioabsorbable fixation of unstable osteochondritis dissecans lesions

BACKGROUND

Osteochondritis dissecans lesions of the knee in adult patients frequently require surgical intervention. However, the ideal method of osteochondral fragment fixation remains uncertain.

PURPOSE

This study was undertaken to determine the clinical, functional, and radiographic outcomes of bioabsorbable fixation for unstable osteochondritis dissecans lesions involving the femoral condyles of the knee in skeletally mature patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Skeletally mature patients with an unstable osteochondritis dissecans lesion of the femoral condyle (Ewing and Voto stages II-IV) treated with bioabsorbable internal fixation and minimum 1-year follow-up were included in this retrospective study cohort. Pre- and postoperative radiographs were reviewed and postoperative Lysholm and International Knee Documentation Committee (IKDC) scores were documented.

RESULTS

A total of 21 knees in 21 patients satisfied the inclusion criteria, and 3 patients were lost to follow-up. The remaining 18 patients were evaluated at a mean of 59 months after surgery (range, 12-154 months). The 14 male and 4 female patients had a mean age of 19 years at the time of surgery (range, 14-39 years). Ewing and Voto classification included 8 stage II lesions, 9 stage III lesions, and 1 stage IV lesion. Fragment fixation methods included bioabsorbable nails (11), pins (3), darts (2), screws (1), and combined screws and darts (1). Mean postoperative Lysholm and IKDC scores were 85 and 82, respectively. Fragment union occurred in 12 knees (67%); the remaining 6 knees (33%) required removal of the loose fragment. Of the 11 patients treated with bioabsorbable nails, 2 (18%) required reoperation for nail back-out.

CONCLUSION

The authors recommend caution when using bioabsorbable fixation for osteochondritis dissecans lesions in skeletally mature patients because of the low rate of clinical healing and high complication rate. Failure with unthreaded fixation devices may be caused by inadequate compression and not necessarily be related to bioabsorbability.

A prospective, randomized clinical study of osteochondral autologous transplantation versus microfracture for the treatment of osteochondritis dissecans in the knee joint in children

PURPOSE

The aim of this study was to compare the outcomes of the arthroscopic mosaic-type osteochondral autologous transplantation (OAT) and microfracture (MF) procedures for the treatment of osteochondritis dissecans (OCD) defects of the femoral condyles of the knee joint in children under the age of 18 years.

TYPE OF STUDY

Prospective, randomized clinical study.

METHODS

Between 2001 and 2005, a total of 50 children with a mean age of 14.3 years (12 to 18) and with symptomatic lesions of the OCD in the femoral condyle of the knee were randomized to undergo either the OAT or the MF procedure. Only those children with grade 3 or 4 (OCD) in the medial or lateral femoral condyle (according to International Cartilage Repair Society, ICRS) were included in the study. Forty-seven patients (94%) were available for follow-up. There were 25 patients in the OAT group and 22 patients in the MF group. The mean duration of symptoms was 23.54+/-4.24 months and the mean follow-up was 4.2 years (range from 3 to 6 y), and none of the children had prior surgical interventions to the affected knee. Children were evaluated using ICRS score, x-rays, magnetic resonance imaging, and second-look arthroscopies.

RESULTS

After 1 year, both groups had significant clinical improvement (P<0.05) and the ICRS functional and objective assessment showed that 23 of 25 (92%) patients had excellent or good results after OAT compared with 19 of 22 (86%) after MF (NS), but 19 of 23 (83%) after OAT and only 12 of 19 (63%) after MF procedure maintained excellent or good results after 4.2 years (range from 3 to 6 y). The MF group showed significant deterioration over the 4.2 years follow-up (P<0.05), but still had significant clinical improvement compared with pretreatment evaluation (P=0.004). There were 9 of 22 (41%) failures in the MF group, and none in the OAT group. Magnetic resonance imaging evaluation according to the ICRS evaluation system showed excellent or good repairs in 19 of 21 patients (91%) after OAT compared with 10 of 18 (56%) after MF.

CONCLUSIONS

At an average of 4.2 years follow-up, our prospective, randomized, clinical study in children under the age of 18 years has shown significant superiority of the mosaic-type OAT over MF for the treatment of osteochondritis dissecans defects in the knee. However, our study has shown that both MF and OAT give encouraging clinical results for children under the age of 18 years.

LEVEL OF EVIDENCE

Level 1: randomized controlled trial, significant difference.