Does operative fixation of an osteochondritis dissecans loose body result in healing and long-term maintenance of knee function?

In Vitro Evaluation of Lateral Femur Condyle Free Chondral Fragment Swelling after Soaking in Normal Saline

OBJECTIVE

After traumatic knee injuries, chondral fragments can avulse off bone with the progeny fragment becoming a loose body. The loose fragment may be larger than expected when trying to surgically repair the fragment back to its original site. The purpose of this study was to determine whether a loose chondral fragment from the lateral femur condyle would increase in size and weight after soaking in normal saline (NS) for 14 days.

DESIGN

Twelve 6-mm OAT (osteoarticular transfer) plugs were harvested from 6 cadaver knees on the lateral femoral condyle to simulate a chondral fragment. The chondral fragments were then placed inside an airtight specimen container with NS (0.9% sodium chloride) and were measured over 14 days.

RESULTS

After 14 days, the chondral fragments showed no increase in diameter as they measured an average of 5.567 ± 0.448 mm on Day 1 and 5.702 ± 0.253 mm on Day 14 (P = 0.183). The chondral fragments showed an increase in mass from an average of 0.058 ± 0.012 g on Day 1 to 0.073 ± 0.012 g on Day 14 (P < 0.001) and an increase in thickness from an average of 2.038 ± 0.346 mm on Day 1 to 2.229 ± 0.297 mm on Day 14 (P = 0.033).

CONCLUSIONS

Chondral fragments in NS increase in mass and thickness over time, but do not change in diameter. When surgeons are evaluating loose chondral fragments for fixation, they should consider that these fragments may appear thicker than the recipient location.

Association of Stability and Size of Unhealed Area With Failure After Internal Fixation for Osteochondritis Dissecans Lesions of the Knee: Radiological Evaluation Using Computed Tomography

BACKGROUND

Open reduction and internal fixation (ORIF) has been widely performed because the osteochondral component of the osteochondritis dissecans (OCD) lesion is the most suitable for reconstructing the joint structure.

PURPOSE

To evaluate radiological healing in terms of reconstructed bony structure after ORIF with bone graft by computed tomography (CT), to identify preoperative prognostic factors for failure, and to determine the cutoff value of radiological healing for risk of failure.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective cohort study of 42 patients (44 knees) who underwent internal fixation with bone graft for OCD lesions of the knee from 2004 to 2018 was conducted. All patients were evaluated 6 months postoperatively, and if not healed 6 months after surgery, they were evaluated by CT periodically thereafter. Radiological healing was judged according to the following 3 criteria: (1) reossification of the OCD lesion, (2) bony continuity between the OCD lesion and basal floor, and (3) reconstructed bony surface of the femoral condyle reconstructed to match the normal joint. Then, the percentage of the radiological healing area was calculated as the ratio of the healing length to the total lesion length. The nonhealing area was calculated by multiplying the sum of the total nonhealing length. Clinical failure was defined as any definitive reoperation for the same OCD lesion, such as fragment excision, or a cartilage restoration procedure. After 6 months, all eligible patients underwent arthroscopy to check for protrusion of the absorbable pin into the joint; the removal of an absorbable pin protruding into the joint was not considered a failure.

RESULTS

Clinical failure was recorded for 4 cases (9.1%). The mean overall percentage of the radiological healing area of OCD 6 months after ORIF with bone graft was 79.5% ± 24.4%, and the mean overall nonhealing area at 6 months was 87.8 ± 107.9 mm2. The percentages of radiological healing area of stable (International Cartilage Regeneration & Joint Preservation Society OCD II) lesions and femoral condylar (lateral femoral condyle + medial femoral condyle) lesions were significantly lower than unstable lesions and femoral groove lesions, respectively (P = .01 and P = .03, respectively). On receiver operating characteristic curve analysis, the cutoff points for predicting a significantly increased risk of failure were 33.9% (sensitivity, 100%; specificity, 100%; area under the curve, 1) for the percentage of radiological healing area and 222.9 mm2 (sensitivity, 95%; specificity, 100%; area under the curve, 0.956) for the nonhealing area 6 months postoperatively.

CONCLUSION

A stable lesion and a femoral condylar lesion were the predictors of poor radiological healing on CT images 6 months after ORIF with bone graft. The risk of failure was increased significantly in cases with only approximately one-third of the lesion healed or in cases with large nonhealing areas at 6 months postoperatively.

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.

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.

Osteochondral Fractures After Patellar Dislocation: Current Concepts

Osteochondral fractures of the knee occur frequently after acute patellar subluxation or dislocation. They can be challenging to manage because of the difficulty in diagnosing and treating these injuries in a timely fashion, in addition to choosing the optimum fixation method. This review presents the background, considerations for patient evaluation, and the best treatment options available for osteochondral fractures.

Predicting Outcomes of Talar Osteochondritis Dissecans Lesions in Children

Background

Reports detailing the rates of radiographic healing after treatment of talar osteochondritis dissecans (TOCD) remain scarce. There is also a paucity of data characterizing treatment outcomes and the risk factors associated with poor outcomes in children with TOCD.

Purpose

To identify factors associated with healing, assess treatment outcomes, and develop a clinically useful nomogram for predicting healing of TOCD in children.

Study Design

Case-control study; Level of evidence, 3.

Methods

This was a retrospective review of all patients ≤18 years of age with TOCD from a single pediatric institution over a 12-year period. Surgical treatment was left to the discretion of the treating surgeon based on standard treatment techniques. Medical records and radiographs were reviewed for patient and clinical data, lesion characteristics, and skeletal maturity. Radiographic healing was evaluated at the 1-year follow-up, and patients with complete versus incomplete healing were compared using multivariable logistic regression models to examine the predictive value of the variables.

Results

The authors analyzed 92 lesions in 74 patients (mean age, 13.1 ± 2.7 years [range, 7.1-18.0 years]; 61% female). Of these, 58 (63%) lesions were treated surgically (drilling, debridement, microfracture, bone grafting, or loose body removal), and the rest were treated nonoperatively. Complete radiographic healing was seen in 43 (47%) lesions. In bivariate analysis, patients with complete healing were younger (P = .006), were skeletally immature (P = .013), and had a lower body mass index (BMI; P < .001) versus those with incomplete healing. In a multivariate regression model, the factors that correlated significantly with the rate of complete healing were age at diagnosis, BMI, and initial surgical treatment. The lesion dimensions were not significantly associated with the likelihood of healing. A nomogram was developed using the independent variables that correlated significantly with the likelihood of complete radiographic healing.

Conclusion

Complete radiographic healing of TOCD lesions was more likely in younger patients with a lower BMI. The effect of initial surgical treatment on potential healing rate was greater in older patients with a higher BMI.

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

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

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.

Surgical Fixation of Chondral-Only Fragments of the Knee: A Case Series With a Mean 4-Year Follow-up

Background:

Chondral-only fragments of the knee have traditionally been treated with excision, with or without cartilage restoration procedures. This is because of the historical assumption that cartilage has limited ability to heal to cancellous or subchondral bone. There is now a growing body of evidence supporting surgical fixation of these fragments.

Hypothesis:

We hypothesized that surgical fixation of chondral fragments would result in acceptable rates of healing with improvement in clinical outcome scores.

Study Design:

Case series; Level of evidence, 4.

Methods:

Data were collected on 15 surgically fixed chondral-only fragments in 14 patients. We retrospectively collected participant demographic information, lesion characteristics, primary mechanism (osteochondritis dissecans vs traumatic shear injury), fixation methods, reoperation information, second-look arthroscopic information, and clinical outcome scores. The mean clinical follow-up was 3.96 years, with a minimum of 1-year follow-up. All patients underwent follow-up magnetic resonance imaging at a mean of 2 years after the index procedure.

Results:

The mean age of our cohort was 17.7 years. We found an 80% survival rate for fixation of the fragments at a mean 4-year follow-up. There were statistically significant improvements in postoperative Knee injury and Osteoarthritis Outcome Score and Tegner scores compared with preoperative scores. Follow-up magnetic resonance imaging scans showed complete healing in 10 knees, partial healing in 2 knees, and loss of fixation in 3 knees. Second-look arthroscopic surgery of 3 knees for reasons other than fragment symptoms showed healing of the fragment, while arthroscopic surgery of 3 symptomatic knees showed loss of fixation.

Conclusion:

Surgical fixation of chondral-only lesions showed an 80% success rate with improvements in the KOOS and Tegner scores.

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

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

Osteochondritis Dissecans in the Knee of Skeletally Immature Patients: Rates of Persistent Pain, Osteoarthritis, and Arthroplasty at Mean 14-Years' Follow-Up

OBJECTIVE

Osteochondritis dissecans (OCD) is a knee disorder of predominately pediatric populations. Because of low incidence, it has traditionally been difficult to study OCD. The purpose of this study was to report long-term outcomes of skeletally immature OCD lesions and determine risk factors for persistent knee pain at final follow-up.

DESIGN

A geographic database of more than 500,000 patients was reviewed to identify patients with knee OCD. Clinical course including operative management, persistent knee pain, and total knee arthroplasty (TKA) were analyzed through review of radiographs, magnetic resonance images, and physician notes.

RESULTS

A total of 95 skeletally immature patients (70 male, 25 female, mean age 12.5 ± 2.0 years) were followed for a mean of 14 years (range, 2-40 years). Fifty-three patients were treated operatively and 42 were treated nonoperatively. At final follow-up, 13 patients noted persistent knee pain, 8 treated operatively versus 5 treated nonoperatively. Risk factors for knee pain were female gender, patellar lesions, and unstable lesions. Four patients (8%) treated operatively and 2 patients (5%) treated nonoperatively developed symptomatic osteoarthritis at a mean of 28.6 years following diagnosis. Three patients underwent TKA at a mean age of 52 years, significantly younger than that observed for primary TKA at our institution (P = 0.004).

CONCLUSIONS

Skeletally immature OCD patients have promising histories, with an estimated 14% risk of persistent knee pain, 6% symptomatic osteoarthritis, and 3% conversion to TKA at 14 years' mean follow-up. Females, patellar lesions, and unstable lesions demonstrated increased persistent knee pain risk. Patients with OCD undergo TKA at a significantly younger age than the general population.

The Influence of Physeal Status on Rate of Reoperation After Arthroscopic Screw Fixation for Symptomatic Osteochondritis Dissecans of the Knee

PURPOSE

To determine if physeal status or other preoperative or intraoperative variables influence the failure rate after arthroscopic reduction and internal fixation of osteochondritis dissecans (OCD) lesions in the knee.

METHODS

Consecutive patients undergoing screw fixation of osteochondral fragments from OCD by a single surgeon from 2005 to 2015 with a minimum 2-year follow-up were included. Demographic, preoperative imaging, and intraoperative data were analyzed to determine risk factors associated with failure, which was defined as the need for a revision reoperation or arthroplasty after initial OCD fixation.

RESULTS

A total of 45 knees met the inclusion criteria, including 26 skeletally mature patients and 19 patients with incompletely closed physes on preoperative imaging. The mean ages of the skeletally mature and immature groups were 18.3 ± 2.5 years and 14.9 ± 2.2 years, respectively (P < .001), and the mean body mass index values were 24.3 ± 3.6 and 23.2 ± 4.0, respectively (P = .432). We excluded 10 patients from the survivorship analysis because they had less than 2 years' follow-up. No statistically significant difference in failure rates was found between skeletally mature and immature individuals (30% and 40%, respectively; P = .721). The only factor significantly associated with fixation failure was undergoing a prior surgical procedure to address the OCD lesion (P = .038). Kaplan-Meier analysis showed rates of overall survivorship from revision reoperations of 88.6% at 1 year and 68.8% at 5 years.

CONCLUSIONS

Outcomes after internal fixation of OCD fragments are guarded, with a fragment survival rate of 65.7% at a mean of 4.1 years' follow-up. No difference in fragment survival was noted in skeletally mature versus immature patients. The only independent risk factor identified for fixation failure was the number of previous operations. LEVEL OF EVIDENCE: Level IV, case series with subgroup analysis.

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

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

Does Internal Fixation for Unstable Osteochondritis Dissecans of the Skeletally Mature Knee Work? A Systematic Review

PURPOSE

To report the rate of radiographic union, patient-reported outcomes, complications, and reoperations after internal fixation of unstable osteochondritis dissecans (OCD) in the skeletally mature knee.

METHODS

A literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Patients were included if they were skeletally mature and underwent internal fixation of an unstable OCD lesion of the knee. Risk of bias assessment was performed using the Methodological Index for Non-randomized Studies scoring system. Surgical technique, rate of union, patient-reported outcomes, complications, and reoperations were collected.

RESULTS

Thirteen studies resulted in 148 patients (150 knees) for inclusion. Patient age ranged from 14 to 45 years. Numerous fixation procedures were used, including biodegradable devices (rods, pins, nails, and screws), metal screws, Kirschner wire, and autologous bone sticks. Overall, reported outcome measures were heterogeneous in nature. The rate of radiographic healing ranged from 67% to 100% across 6 studies. Improved subjective results and Hughston criteria on final follow-up ranged from 83% to 100% across 4 studies each. Mean postoperative Lysholm scores ranged from 42 to 98 in studies that reported them. Both complication and reoperation rates ranged from 0% to 44%. The most commonly performed reoperations were loose body excision and cartilage resurfacing procedures.

CONCLUSIONS

A variety of surgical techniques are available for treatment of unstable OCD lesions in the skeletally mature knee. In this systematic review, internal fixation of the native fragment showed acceptable rates of radiographic union and improved patient-reported outcomes relative to other techniques.

LEVEL OF EVIDENCE

Level IV, systematic review of level III-IV studies.

Open Reduction, Bone Grafting, and Internal Fixation of Osteochondritis Dissecans Lesion of the Knee

Osteochondritis dissecans (OCD) of the femoral condyle is an idiopathic focal bone abnormality affecting the subchondral bone and can result in unstable osteochondral lesions. The treatment of unstable OCD lesions with open reduction and internal fixation with metallic compression screws is well documented in the literature. Fixation is performed to prevent dislodgement of unstable OCD lesions or fix displaced fragments that have been surgically reduced. The procedure is performed by approaching the knee through a midline incision and medial parapatellar arthrotomy. The lesion is identified, and a scalpel is used to incise the cartilage circumferentially, leaving 1 side intact, to create a "trap door" flap. The OCD fragment is lifted from the bed, and the bed is prepared by debriding the fibrocartilage scar and bone-grafting the bed. The osteochondral fragment is reduced back to the bed, and guidewires are placed to secure the reduction and plan screw trajectories. Guide pins are overdrilled and Herbert compression screws are placed to secure the OCD fragment. The wound is irrigated and closed. Complications are rare, but later screw removal is typically recommended. Reported outcomes are satisfactory, with an 80% rate of radiographic healing and good-to-excellent patient-reported outcomes.

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.

Internal Fixation of Unstable Osteochondritis Dissecans: Do Open Growth Plates Improve Healing Rate?

BACKGROUND

Osteochondritis dissecans (OCD) is a disorder of unknown origin that can affect knees in skeletally mature and immature patients. Surgical management is an important cornerstone of treatment for unstable OCD lesions.

PURPOSE

To determine the (1) healing rate after internal fixation of unstable OCD between skeletally immature and mature knees, (2) risk factors for failure, and (3) patient-reported outcomes among healed patients.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A multicenter retrospective cohort study was conducted with patients who underwent internal fixation of unstable knee OCD lesions from 2000 to 2015. Skeletal immaturity was defined as open or partially open physes. Healing was assessed through clinical findings and imaging. Definitive reoperation for the same OCD lesion was classified as failure.

RESULTS

Among 87 patients included, 66 (76%) had healed lesions at ≥2 years postoperatively, while 21 (24%) failed. Skeletal maturity made no significant difference in failure rate (risk ratio, 0.68; 95% CI, 0.29-1.72; P = .40). For skeletally immature patients, lateral versus medial condylar location conferred an increased hazard of 18.2 (95% CI, 1.76-188.07; P < .01). Multivariate analysis factoring in skeletal maturity showed that lateral condylar location was an independent risk factor for failure (hazard ratio, 4.25; 95% CI, 1.47-19.85; P < .01). Mean patient-reported outcome scores (International Knee Documentation Committee [IKDC] and Knee injury and Osteoarthritis Outcome Score [KOOS]) increased significantly after surgery, except the KOOS symptoms score for the skeletally mature group. Final scores (mean ± SD) were as follows at a mean follow-up of 60 months (range, 24-166): IKDC, 83.5 ± 20.2; KOOS pain, 89.7 ± 14.1; KOOS symptoms, 87.4 ± 18.4; KOOS activities of daily living, 93.9 ± 12.7; KOOS sports, 80.7 ± 25.9; KOOS quality of life, 78.9 ± 23.1.

CONCLUSION

Skeletally immature and mature patients heal at comparable rates after internal fixation of OCD lesions, resulting in functional and subjective improvement. Lateral femoral condylar lesion location is an independent risk factor for failure.

Mid and long term outcomes after fixation of osteochondritis dissecans

OBJECTIVE

To assess the longitudinal outcomes of osteochondritis dissecans (OCD) fixation and to detect the influencing factor for the results of OCD.

METHODS

22 OCD fixation using bioabsorbable pins were assessed Lysholm score, Tegner activity scale and KOOS4 at preoperative, postoperative short (3.0 years) and mid-long (11.9 years) term.

RESULTS

Postoperative Lysholm score was significantly better than the preoperative time. There was no factor influencing KOOS4 at mid-long term.

CONCLUSION

OCD fixation contributes good results for a long time regardless of skeletal maturity, the size and the severity of OCD.

Nonoperative Management of Osteochondritis Dissecans of the Knee: Progression to Osteoarthritis and Arthroplasty at Mean 13-Year Follow-up

BACKGROUND

Osteochondritis dissecans (OCD) is a disorder of subchondral bone that commonly affects the knee.

PURPOSE

To (1) evaluate the rate of arthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated nonoperatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Eighty-six patients (mean age, 21.4 years) with OCD lesions treated nonoperatively were identified between 1976 and 2014. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to arthritis was obtained from the medical record. Factors predictive of arthritis and arthroplasty (age, sex, body mass index [BMI], and lesion location) were examined.

RESULTS

At a mean ± SD follow-up of 12.6 ± 9.8 years from diagnosis, 13 patients (15%) were diagnosed with arthritis, corresponding to a cumulative incidence of 5.0% at 5 years, 10.0% at 10 years, 20.0% at 25 years, and 30.0% at 35 years. The cumulative incidence of arthroplasty was 1.0% at 5 years, 3.0% at 10 years, 8.0% at 25 years, and 8.0% at 35 years. BMI at diagnosis greater than 25 kg/m² (hazard ratio [HR], 15.4; 95% CI, 1.9-124.5), patellar OCD lesions (HR, 15.0; 95% CI, 1.3-345.3), and diagnosis as an adult (HR, 21.7; 95% CI, 2.7-176.3) were factors associated with an increased risk of arthritis.

CONCLUSION

Arthritis after nonoperative treatment of OCD lesions is a challenging problem, with an estimated 30% cumulative incidence at 35 years after diagnosis. In contrast, the long-term rate of arthroplasty is low. BMI at diagnosis greater than 25 kg/m² and patellar OCD lesions are predisposing factors for arthritis. Diagnosis of OCD as an adult was associated with a greater risk of arthritis.

High Rate of Osteoarthritis After Osteochondritis Dissecans Fragment Excision Compared With Surgical Restoration at a Mean 16-Year Follow-up

BACKGROUND

Osteochondritis dissecans (OCD) is a disorder of subchondral bone that causes adverse effects on the overlying cartilage and commonly affects the knee. The incidence of OCD and its long-term effect on the knee joint are controversial. Hypothesis/Purpose: The purpose of this study was to (1) evaluate the rate of osteoarthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. The investigators hypothesized that OCD lesions diagnosed after skeletal maturity and treatment with fragment excision would be predictive of a diagnosis of osteoarthritis.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The investigators identified 221 patients (mean ± SD age, 26.1 ± 13.6 years) with OCD lesions treated operatively between 1976 and 2010 and followed for 16.3 ± 11.4 years (mean ± SD) from diagnosis. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to osteoarthritis was obtained from the medical record. Surgical treatment was classified as fragment excision, fragment preservation (lesion drilling and/or fragment fixation), or chondral defect grafting (osteochondral allograft or autograft). Factors predictive of osteoarthritis and arthroplasty were examined.

RESULTS

There were 134 patients in the fragment excision group, 78 patients in the fragment preservation group, and 9 patients in the chondral defect grafting group. In the fragment excision group, the cumulative incidence of osteoarthritis was 12.0% at 5 years, 17.0% at 10 years, 26.0% at 15 years, 39.0% at 20 years, and 70% at 30 years. The cumulative incidence of arthroplasty was 2.0% at 5 years, 4.0% at 10 years, 4.0% at 15 years, 10.0% at 20 years, and 32.0% at 30 years. In the fragment preservation group, the cumulative incidence of osteoarthritis was 3.0% at 5 years, 7.0% at 10 years, 16.0% at 15 years, 25.0% at 20 years, and 51% at 30 years. The cumulative incidence of arthroplasty was 0.0% at 5 years, 0.0% at 10 years, 3.0% at 15 years, 6.0% at 20 years, and 11.0% at 30 years. No patients in the chondral defect grafting group developed osteoarthritis or underwent arthroplasty. Body mass index (BMI) greater than 25 kg/m² (hazard ratio [HR] 3.3; 95% CI, 1.6-7.0), older age at diagnosis (HR 4.9; 95% CI, 1.8-17.3), and fragment excision (HR 2.3; 95% CI, 1.2-4.6) were predictive of osteoarthritis.

CONCLUSION

OCD patients treated with fragment excision have a high rate of osteoarthritis and knee arthroplasty at long-term follow-up. In contrast, patients treated with fragment preservation or chondral defect grafting have lower rates of osteoarthritis and arthroplasty. BMI greater than 25 kg/m², older age at diagnosis, and fragment excision were predictive of osteoarthritis.

Internal Fixation of Unstable Osteochondritis Dissecans in the Skeletally Mature Knee with Metal Screws

PURPOSE

Several bioabsorbable and metal options are available for internal fixation of an unstable osteochondritis dissecans (OCD) lesion, but currently there are little data on outcomes with metal headless compression screws in the adult knee. The purpose of this study was to determine (1) the radiographic healing rates, (2) midterm clinical outcomes, and (3) comparison between healed and unhealed OCD fragments after use of headless metal compression screws for the treatment of unstable OCD lesions in the knees of skeletally mature patients.

METHODS

Retrospective chart review for all skeletally mature patients who presented with unstable femoral condyle OCD lesions of the knee was conducted. All patients underwent open or arthroscopic reduction and internal fixation using headless metal compression screws. Preoperative and postoperative radiographs were reviewed with healing defined as radiographic evidence of union of the OCD progeny fragment with the condyle. Clinical outcome data were collected retrospectively using 3 validated outcome scores: International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Marx.

RESULTS

Twenty-two knees in 22 patients with a mean age of 21 years (range= 14-37 years) were followed for an average of 8.7 years (range = 2-22 years). Metal, headless, cannulated compression screws were used in all 22 cases. At a mean of 31 months postoperatively (range = 2-262), fragment union was observed in 18 knees (82%). The remaining 4 knees (18%) required loose fragment excision and hardware removal at a mean of 9 months (range = 2-16 months) postoperatively. Mean postoperative Marx score was 7 (range = 0-16), the mean postoperative IKDC score was 85 (range = 62-100), and mean KOOS scores included KOOS Pain (93; range = 69-100), KOOS Symptoms (86; range = 71-100), KOOS ADL (98; range = 90-100), KOOS Sports (82; range = 50-100), and KOOS QOL (76; range = 50-100).

CONCLUSION

Headless metal compression screws provide a satisfactory union rate for treatment of unstable OCD lesions of the femoral condyles in skeletally mature patients. Patients achieving union have good knee function, maintain satisfactory activity levels, and have superior knee outcomes compared with those that failed to heal after fixation at mid to long-term follow-up.

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.

Arthroscopic delivery of cancellous tibial autograft for unstable osteochondral lesions in the adolescent knee

The appropriate surgical technique for the treatment of unstable osteochondral lesions of the knee remains unclear and had been traditionally described with an open arthrotomy. Administration of bone grafting material in the knee may be performed for a variety of pathologic conditions, including unstable osteochondritis dissecans, traumatic osteochondral defects, or subchondral fracture nonunion, or for preparation of residual tunnels during revision anterior cruciate ligament reconstruction. Although various grafting materials have been described in the literature, cancellous autograft remains the gold standard for treatment safety and efficacy. We describe a successful technique for arthroscopic delivery of autogenous bone graft during fixation of unstable osteochondral lesions of the knee. When the indication for grafting is established, cancellous autograft is harvested from the proximal tibia, undergoes morcellation, and is soaked in bone marrow aspirate obtained through the harvest window. The bone graft is then packed into a modified tuberculin syringe. After arthroscopic preparation of the unstable osteochondral fragment and the respective donor surface, the tuberculin syringe is placed through a standard arthroscopy portal and the bone graft is introduced into the defect under direct visualization, followed by an appropriate osteochondral fixation technique.

Surgical management of osteochondritis dissecans of the knee in the paediatric population: a systematic review addressing surgical techniques

PURPOSE

Several case series have been published exploring a variety of surgical treatments for osteochondritis dissecans (OCD) in patients 18 years and younger, but a systematic review is currently lacking. This systemic review identifies the various surgical techniques reported in the literature for treating OCD and assesses the effectiveness of these treatments based on functional outcomes and radiographic healing.

METHODS

A search of the EMBASE and MEDLINE databases was performed to identify clinical studies reporting outcomes of surgical management of OCD in the knee. A quality assessment of the included articles was conducted independently by 2 reviewers using a quality assessment tool developed by Yang et al.

RESULTS

A total of 25 papers including 470 patients aged ≤18 years (516 lesions) met the eligibility criteria and were reviewed. Surgical techniques for stable lesions included (arthroscopic and open) transarticular drilling, either alone (41%) or with bioabsorbable pin fixation (3%), extra-articular drilling (29%) and fixation with bioabsorbable screws (4%) or bone pegs (4%). For unstable lesions, surgical techniques included (arthroscopic and open) fixation with bioabsorbable pins (9%), metal screws (4%), bone pegs (4 %), osteochondral plugs (3%) or bioabsorbable screws (2%), as well as transarticular drilling with bioabsorbable pin fixation (3%) and drilling with metal screw fixation (2%).

CONCLUSION

The most common techniques were transarticular drilling for stable lesions and bioabsorbable pin fixation for unstable lesions. The key findings were that the vast majority of lesions healed postoperatively, regardless of technique, and that high-quality trials are required to more appropriately compare the effectiveness of techniques.

LEVEL OF EVIDENCE

Systematic review, Level IV.

The Long-Term Clinical Outcomes Following Autogenous Bone Grafting for Large-Volume Defects of the Knee: 12- to 21-Year Follow-Up

OBJECTIVE

We report the long-term clinical outcomes of patients who underwent autogenous bone grafting of large-volume osteochondral defects of the knee due to osteochondritis dessicans (OCD) and osteonecrosis (ON). This is the companion report to one previous published on the biological response. We hypothesized that these grafts would integrate with host bone and the articular surface would form fibrocartilage providing an enduring clinical benefit.

DESIGN

Three groups (patients/knees) were studied: OCD without a fragment (n = 12/13), OCD with a partial fragment (n = 14/16), and ON (n = 25/26). Twenty-five of 52 patients were available for clinical follow-up between 12 and 21 years. Electronic medical records provided comparison clinical information. In addition, there were plain film radiographs, MRIs, plus repeat arthroscopy and biopsy on 14 patients.

RESULTS

Autogenous bone grafts integrated with the host bone. MRI showed soft tissue covering all the grafts at long-term follow-up. Biopsy showed initial surface fibrocartilage that subsequently converted to fibrocartilage and hyaline cartilage at 20 years. OCD patients had better clinical outcomes than ON patients. No OCD patients were asymptomatic at anytime following surgery. Half of the ON patients came to total knee replacement within 10 years.

CONCLUSIONS

Autogenous bone grafting provides an alternative biological matrix to fill large-volume defects in the knee as a singular solution integrating with host bone and providing an enduring articular cartilage surface. The procedure is best suited for those with OCD. The treatment for large-volume articular defects by this method remains salvage in nature and palliative in outcome.

Osteochondritis dissecans with a large osteochondral free body in the posterolateral compartment of the knee: a case report

A large osteochondral fragment trapped in the posterolateral compartment of a knee was removed from a posteromedial portal through the trans-septal portal and fixed on an osteochondral defect of the lateral femoral condyle in a 16 year-old boy. When a free body in the posterolateral compartment is so large that enlargement of the portal site is required for removal, doing so from a posteromedial portal is safer and easier than from a posterolateral portal.

Evaluation of cartilage, synovium and adipose tissue as cellular sources for osteochondral repair

Osteochondral lesions are a major cause of pain and disability in several species including dogs, horses and human beings. The objective of this study was to assess three potential sources of canine cells for their osteochondral regenerative potential. Cartilage, synovium and adipose tissue cells were grown in pellet culture in chondrogenic or osteogenic media. Cartilage-derived pellets displayed the best chondrogenic differentiation as indicated by significantly higher COL2A1 and SOX9 mRNA expression, greater glycosaminoglycan content, and higher retention of Safranin-O stain compared to the synovium and adipose-derived cells. Following application of the osteogenic media, all three cell sources exhibited small areas of positive alizarin red staining. Poor intracellular alkaline phosphatase activity was found in all three cell types when stimulated although osteocalcin and RUNX2 expression were significantly increased. Cells isolated and cultured from canine articular cartilage retained their specific chondrocytic phenotype. Furthermore, canine adipocytes and synovial cells did not undergo chondrogenic differentiation and did not exhibit evidence of multipotency. Although osteogenic differentiation was initiated at a genomic level, phenotypic osteoblastic differentiation was not observed. The findings of this study suggest that cells isolated from canine adipose tissue and synovium are sub-optimal substitutes for chondrocytes when engineering articular cartilage in vitro.

Operative Fixation of Chondral Loose Bodies in Osteochondritis Dissecans in the Knee: A Report of 5 Cases

BACKGROUND

Osteochondritis dissecans (OCD) can progress to loose body formation, with or without subchondral bone attachment to the lesion. The efficacy of internal fixation of chondral loose bodies has not been determined.

HYPOTHESIS

Operative fixation of cartilaginous loose bodies would result in (1) healed OCD at second-look arthroscopy, (2) restored cartilage appearance on magnetic resonance imaging (MRI), and (3) nearly normal knee function, as determined by patient-reported outcome scores.

STUDY DESIGN

Retrospective case series; Level of evidence, 4.

METHODS

Five patients who underwent cartilaginous loose body fixation were identified. Lesions were located on the lateral trochlea (n = 2) and medial femoral condyle (n = 3) (mean size, 2.5 cm(2)). Loose bodies were reattached with compression screws through mini-arthrotomy or arthroscopy. Patients were nonweightbearing for 12 weeks postoperatively. After 12 weeks, screws were removed arthroscopically, and OCD stability was evaluated. Three patients underwent MRI to determine articular cartilage status. Images were evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) score. Patients were interviewed and completed the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire.

RESULTS

Four patients had stable lesions at 12 weeks after surgery. One patient had slight motion to one-third of the lesion and stability to the remaining two-thirds. Three patients underwent an MRI. The mean time from surgery to MRI was 3.1 years. Mean MOCART score was 72.0 ± 10.4. One patient required repeat arthroscopy 1 year after initial fixation for debridement and arthroscopic drilling of an incompletely healed area of the lesion. Four patients completed the KOOS questionnaire. The mean time to KOOS completion was 4.6 years. Mean KOOS subscales for knee pain (91.0 ± 8.9), knee symptoms (83.0 ± 7.9), and function in activities of daily living (91.9 ± 10.6) were similar to published age-matched controls; however, scores for sports and recreation function (70.0 ± 17.8) and knee-related quality of life (67.2 ± 12.9) were lower.

CONCLUSION

Operative fixation of chondral loose bodies, without macroscopically visible subchondral bone attachment, resulted in lesion stability at second-look arthroscopy. At final follow-up, patients had no substantial pain and normal function in activities of daily life compared with controls; however, knee-related quality of life and sport and recreation function were reduced, and 1 patient required reoperation for an unhealed portion of the lesion.

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.

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.

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.

The Biological Response following Autogenous Bone Grafting for Large-Volume Defects of the Knee: Index Surgery through 12 to 21 Years' Follow-up

OBJECTIVE

This report focuses on the biological events occurring at various intervals following autogenous bone grafting of large-volume defects of the knee joint's femoral condyle secondary to osteochondritis dissecans (OCD) or osteonecrosis (ON). It was hypothesized that the autogenous bone graft would integrate and the portion exposed to the articular surface would form fibrocartilage, which would endure for years.

METHODS

Between September 29, 1987 and August 8, 1994, there were 51 patients treated with autogenous bone grafting for large-volume osteochondral defects. Twenty-five of the 51 patients were available for long-term follow-up up to 21 years. Patient follow-up was accomplished by clinical opportunity and intentional research. Videotapes were available on all index surgeries for review and comparison. All had preoperative and postoperative plain film radiographs. Long-term follow-up included MRI up to 21 years. Second-look arthroscopy and biopsy were obtained on 14 patients between 8 weeks and 20 years.

RESULTS

Radiological assessment showed the autogenous bone grafts integrated with the host bone. The grafts retained the physical geometry of the original placement. MRI showed soft tissue covering the grafts in all cases at long-term follow-up. Interval biopsy showed the surface covered with fibrous tissue at 8 weeks and subsequently converted to fibrocartilage with hyaline cartilage at 20 years.

CONCLUSION

Autogenous bone grafting provides a matrix for large osteochondral defects that integrates with the host bone and results in a surface repair of fibrocartilage and hyaline cartilage that can endure for up to 20 years.

Hybrid fixation: evaluation of a novel technique in adult osteochondritis dissecans of the knee

PURPOSE

Treatment of osteochondritis dissecans of the adult knee requires bone and cartilage integration of the loose fragment. Screw fixation provides primary stability but does not guarantee bony consolidation. Additional biological fixation using osteochondral grafts-hybrid fixation-could improve fragment integration.

METHODS

The study included seven patients [median age 21 years (15-29)] who underwent surgery for Bedouelle IIB or III osteochondritis dissecans of the medial femoral condyle. The technique involved metal screw fixation of the fragment. Mosaicplasty grafts were then press-fitted through the fragment. Cancellous autograft was utilized in the cases of subchondral bone loss. Patients were followed up clinically and radiologically (Hughston score). Screws were removed arthroscopically at 3 months and the cartilage graded using the International Cartilage Repair Society score. Fragment integration was evaluated by MRI Arthrogram (4 patients).

RESULTS

Median follow-up was 27 months (7-35). Median clinical Hughston score was 2 (0-3) preoperatively and 4 (2-4) postoperatively. Median radiological Hughston score was 3 (2-4) and 4 (3-4). During arthroscopic removal of metalwork, osteochondritis fragments were well integrated in all cases. The International Cartilage Repair Society score was I in one patients, II in five, and III in one. Postoperative MRI arthrograms confirmed that cartilage and bone integration was complete.

CONCLUSIONS

Isolated screw fixation of osteochondritis dissecans in adults provides poor bony integration. Mosaicplasty is an alternative but does not retain normal condylar anatomy. The hybrid fixation technique adds a biological "booster" to osteochondritis fixation, with excellent short-term outcome. Further studies are required to investigate the long-term results.

Remodeling of articular cartilage and subchondral bone after bone grafting and matrix-associated autologous chondrocyte implantation for osteochondritis dissecans of the knee

BACKGROUND

Osteochondritis dissecans (OCD) of the knee is a challenging problem. Previously, the authors implemented a novel 1-step surgical procedure for OCD treatment consisting of matrix-associated autologous chondrocyte implantation (ACI) and simultaneous bone reconstruction including the subchondral lamina.

PURPOSE

This study presents the 2-to 5-year results after this technique, assessing correlations of clinical function and cartilage and bone remodeling processes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-six patients with symptomatic condylar knee OCD (International Cartilage Repair Society OCD III/IV) were treated with matrix-associated ACI and monocortical cancellous cylinders for defect filling and subchondral bone plate reconstruction using cortical graft layers as novel subchondral lamina. Evaluations were performed with clinical rating scales and 1.5-T magnetic resonance imaging using the magnetic resonance observation of cartilage repair tissue (MOCART) score and a newly implemented subchondral lamina remodeling grade.

RESULTS

The defect size was 5.3 ± 2.3 cm(2). The defect depth was 8.7 ± 2.4 mm. After a follow-up of 39.8 ± 12.0 months, all scores improved significantly. Nineteen patients (73%) reached good/excellent results in the Lysholm-Gillquist score (preoperatively: 53.2 ± 18.0 points; latest follow-up: 88.5 ± 9.5 points) and the Cincinnati knee rating score (preoperatively: 51.7 ± 13.0 points; latest follow-up: 84.6 ± 11.7 points) and significant improvements in the subjective International Knee Documentation Committee (IKDC) score by 27.9% (preoperatively: 50.5% ± 16.1%; latest follow-up: 78.4% ± 13.4%). The MOCART score reached 62.4 ± 18.9 points. The clinical improvement and tissue remodeling occurred simultaneously and timed; thus, the cartilage defect filling and the lamina remodeling grades correlated significantly with each other, the follow-up time, and almost all clinical scores.

CONCLUSION

The simultaneous reconstruction of deep osteochondral defects of the knee OCD with monocortical cancellous cylinders and matrix-associated ACI is a biological, 1-step alternative to osteochondral cylinder transfer or conventional ACI that leads to good clinical and magnetic resonance imaging results after an intermediate follow-up period. The present study demonstrated simultaneous remodeling processes of articular cartilage repair tissue and subchondral lamina; this synchronization is not yet understood and deserves further investigation.

Fixation of detached osteochondritis dissecans lesions with bioabsorbable pins: clinical and histologic evaluation

PURPOSE

The purpose was to evaluate the effect of fixation of detached free fragments of osteochondritis dissecans (OCD) (International Cartilage Repair Society OCD IV) on not only the clinical outcome, including functional and radiographic assessment, but also postoperative second-look arthroscopic and histologic evaluation.

METHODS

Nine International Cartilage Repair Society OCD IV fragments were fixed with bioabsorbable pins made of poly-L-lactic acid after curettage of the bed and bone grafting. In 4 cases with severe cartilage damage in the fragments, after resection of the damaged part, trimmed fragments were fixed and osteochondral autologous transplantation was performed to cover the remaining defects. The follow-up period was at least 2 years (range, 2 to 3 years). Lysholm score and computed tomography (CT)/magnetic resonance imaging (MRI), second-look arthroscopy, and biopsy findings were examined postoperatively.

RESULTS

All patients ultimately could return to previous sports activity, and the mean postoperative Lysholm score was 97 (range, 90 to 100). At 6 months, CT/MRI scans showed complete union and smooth continuity of articular surface in all cases. Second-look arthroscopy in 7 cases showed that fixed fragments were stable and that there were no progressive degenerative changes in the cartilage. Postoperative histologic examination in 4 cases showed almost normal cartilage from surface to bottom in terms of viability and quality. In addition, new bone trabeculae were covering dead bone trabeculae, which is called creeping substitution.

CONCLUSIONS

Our study shows good short-term clinical results, as well as confirmation of healing on CT/MRI and second-look arthroscopy.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Midterm results of surgical treatment for adult osteochondritis dissecans of the knee

BACKGROUND

Determination of appropriate treatment options for adult osteochondritis dissecans is difficult, as most published papers on surgical osteochondritis dissecans treatment report outcomes in a population consisting of both adult and juvenile patients.

PURPOSE

This study examines the outcomes of surgical procedures in patients with adult osteochondritis dissecans.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The cohort included 46 adult patients (48 knees) with adult osteochondritis dissecans of the knee who had undergone surgical treatment (debridement, drilling, loose-body removal, arthroscopic reduction and internal fixation, microfracture, osteochondral allograft, or autologous chondrocyte implantation). The average patient age was 34 +/- 9.5 years (range, 20-49) and patients were followed for 4.0 +/- 1.8 years. The mean defect size was 4.5 +/- 2.7 cm(2). Outcomes were assessed via clinical assessment and established outcome scales, including the Lysholm, International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner, Cincinnati, and Short Form-12.

RESULTS

Statistically significant improvement (P < .05) was noted in all outcome scales, including Noyes, Tegner, Lysholm, IKDC, KOOS (subdivided into 5 categories including Pain, Symptoms, Activities of Daily Living, Sport, and Quality of Life), Short Form-12 Physical, and Short Form-12 Mental. Seven knees (14%) had clinical failure of the initial treatment and underwent a revision procedure at a mean follow-up of 14 months. Patients treated with arthroscopic reduction and internal fixation and loose-body removal demonstrated a statistically higher postoperative percentage score increase for the KOOS Sport (P = .008) and KOOS Quality of Life (P = .03) categories than those treated with an osteochondral allograft.

CONCLUSION

Patients with adult osteochondritis dissecans of the knee, treated with surgical cartilage procedures, show durable function and symptomatic improvement at a mean 4.0 years of follow-up. Patients treated with arthroscopic reduction and internal fixation and loose-body removal demonstrated a greater improvement in outcome scores than those treated with osteochondral allograft.