Summary

OCD treated surgically are most likely to present with mechanical symptoms, and they have lower probability of healing, based on Wall's nomogram. Clinical symptoms and MRI study are essential in the follow-up of patients with juvenile OCD for determining the therapeutic modality to follow

Abstract

Introduction

Osteochondritis dissecans (OCD) of the knee is an idiopathic and focal pathology, with involvement of the subchondral bone and underlying articular cartilage, in which the diagnosis is generally made during adolescence. Although in adults the treatment is mainly surgical, in younger patients healing can be obtained with conservative management, based on restriction of activities and offload of the affected extremity. Magnetic resonance imaging (MRI) allows a better characterization of the lesion in terms of size, area, and location, as well as characteristics that suggest instability, free fragments, and associated lesions, helping decision making for the management of this pathology.

Objective

To compare the characteristics and probability of healing of lesions in 2 groups of patients diagnosed with OCD of the knee, based on their subsequent definitive management.

Methods

Retrospective study of a clinical series. A database of all patients diagnosed with OCD in 2 centers from 2006 to 2022 was analyzed. The inclusion criteria were patients under 18 years, diagnosed with OCD of the knee. Patients with concomitant knee injuries were excluded. The sample was divided into a group of 19 patients with conservative management and a group of 18 patients with surgical management to subsequently compare the results between the two groups. Clinical records were reviewed for demographic and clinical data, MRI evaluation to determine the location and size of the lesion prior to treatment. Subsequently, each patient was assigned a score to calculate the probability of healing of the lesion, according to the nomogram proposed by Wall in 2008. The statistical analysis included Fisher's test for categorical variables and "t student" test for continuous variables.

Results

The average age was 12.7 years in the conservative group and 13.83 in the surgical group. 54% of the patients were males. 78.3% of the injuries occurred in the medial femoral condyle. There were no significant differences in terms of sex (p=0.440), age (p=0.1338), laterality (0.433), location of the lesion (p=0.440) or physis status (p=0.256) between the two groups. The lesions were visible in 75.6% of the radiographs. All patients in the conservative management group presented only pain, unlike the surgical group, in which 6 patients (35.3%) presented mechanical symptoms and 11 (64.7%) pain, with a statistically significant difference (p= 0.006). There were no differences in the area of the lesion between both groups (p=0.653), size in the coronal (p=0.4773) or sagittal axis (p=0.9876). Statistically significant differences were observed between both groups in the score calculated according to the Wall nomogram, being higher in the conservative management group (13.3 points vs 11.69 points; p=0.0048). The conservative management group presented a healing probability of 81% (53-96%) compared to 65% (40-91%) in the surgical management group, a statistically significant difference between both groups (p= 0.003).

Conclusion

OCD treated surgically are most likely to present with mechanical symptoms, and they have lower probability of healing, based on Wall's nomogram.
Clinical symptoms and MRI study are essential in the follow-up of patients with juvenile OCD for determining the therapeutic modality to follow