[Clinical value of conventional radiology and MRI in assessing osteochondrosis dissecans stability]

MR imaging of the articular cartilage of the knee and ankle

Cartilage abnormalities in the knee and ankle are a common source of pain and are often difficult to diagnose clinically or radiographically. MR imaging is a valuable tool for diagnosing and characterizing cartilage lesions of both the knee and ankle. An understanding of the appearance of cartilage, and an understanding of how and when to report cartilage injury in the knee and ankle based on current grading systems allows the radiologist to provide the most helpful reports to referring clinicians. This article presents the range of cartilage pathologies in the knee and ankle and provides clinically relevant guidelines.

SPECT/CT in the management of osteochondral lesions of the talus

BACKGROUND

The treatment of osteochondral lesion of the talus (OLT) is mainly based upon the stage of the disease so accurate imaging is crucial. SPECT/CT combines bone scan with high-resolution CT and can provide functional-anatomical images in a single stage. The purpose of this study was to assess the value of SPECT/CT in the management of OLT.

MATERIALS AND METHODS

From 2004 to 2009, 22 patients with OLT were identified that had both SPECT/CT and MRI of the foot and ankle. All charts were reviewed to ascertain the reason for ordering the SPECT/CT and the additional information obtained. AOFAS outcome scores were calculated at the time of followup.

RESULTS

Twelve patients underwent ankle arthroscopy for debridement or drilling of the osteochondral lesion. The mean AOFAS score in these 12 patients was 83.6. SPECT/CT helped preoperative planning by identifying the exact location of the active lesion, especially in multifocal disease or revision surgeries while showing the depth of the active lesion. Ten patients had conservative management due to minimal or no activity over the lesion on SPECT/CT images. The mean AOFAS score in these ten patients was 78.8 which was comparable to the operative group.

CONCLUSION

We believe SPECT/CT was able to provide additional diagnostic value by demonstrating a co-existing pathology as a potential cause of pain and in preoperative planning by showing the depth of activity and the precise location of the active segment in multiple lesions.

[Efficacy of x-ray assessment in emergency surgical departments: an evaluation in a level I trauma center]

BACKGROUND

The aim of the study was to ascertain the state of the art in x-ray assessment in an emergency surgical department.

METHODS

From August 2008 to February 2009 a total of 1,588 plain x-rays of 658 patients from the emergency department were included in this study. The images were assessed by 3 experienced orthopedic surgeons and 1 experienced radiologist. The incidence of missed traumatic lesions and suspected lesions and the treatment of these patients were noted.

RESULTS

A total of 136 pathological cases with 238 pathological x-ray findings were found. The mean rate of missed lesions was 13% of the assessed cases. Despite the fact that the rate of missed lesions varied from 9-25% depending on the level of experience, all patients were treated adequately. The quality of x-ray assessment improved with the level of training of the individual doctors.

CONCLUSION

The present situation is in need of improvement but it is not critical. Junior medical staff should undergo a special training in x-ray assessment.

[Treatment of osteochondritis dissecans of the knee joint]

Osteochondritis dissecans (OD) is a lesion of the subchondral bone which can result in sequestration of the osteochondral lesion. It is categorized into 4 stages, and juvenile and adult forms depending on the distal femoral physis maturity. Prognosis and treatment depends on age and stage. Prognosis is favorable in stable lesions (stage I and II) at typical location (medial femoral condyle) in a child with open physes. Therefore non-operative treatment is indicated. If there is no response to non-operative treatment drilling to create channels for potential revascularization can be done. In unstable lesions (stage III and IV) operative treatment is necessary. Long-term results after excision of the fragment with or without drilling of the defect site are poor. Therefore refixation of an intact osteochondral fragment or biologic reconstruction should be tried.

MRI of sports-related injuries of the foot and ankle: part 1

The ankle is one of the most frequently injured joints in the course of sports activities. MR imaging has become the modality of choice in the evaluation of most of these lesions, especially in competitive athletes. The purpose of this article is: (1) To illustrate the MR imaging features of a great number of sports-related injuries of the ankle, correlating it with lesional mechanisms and clinical findings, and (2) To review the role of MR imaging in clinical management and surgical planning of these injuries, especially in competitive athletes. In order to a better understanding of these lesions, a classification based on the anatomic origin are outlined. The spectrum of injuries has been classified in: (1) osseous lesions, (2) ligamentous injuries, (3) tendinous lesions, (4) impingement impingement, and (5) plantar fascial lesions.

Osteochondral lesions of the talus: a new magnetic resonance grading system with arthroscopic correlation

PURPOSE

The purpose of this study was to show that magnetic resonance imaging (MRI) can accurately and noninvasively evaluate the articular cartilage overlying osteochondral lesions of the talus, using arthroscopy as the standard, and provide information about lesion stability. A classification system applicable to both MRI and arthroscopy is proposed.

TYPE OF STUDY

Retrospective review with MRI and arthroscopy correlation.

METHODS

A retrospective analysis involving 26 men and 28 women who underwent MRI of the ankle and in whom arthroscopy had been performed. The talar dome cartilage was evaluated using the following grading system: 0, normal cartilage; 1, abnormal signal but intact; 2, fibrillation or fissures not extending to bone; 3, flap present or bone exposed; 4, loose undisplaced fragment; 5, displaced fragment. There was a history of trauma in 80% of cases.

RESULTS

At surgery, 14 ankle joints had intact cartilage and 40 showed osteochondral lesions. MRI correctly identified all 40 osteochondral lesions and all 14 normal ankles. MRI correctly graded 33 of 40 (83%) of the osteochondral lesions using the described 5-point scale. Of the remaining 7 lesions, all were identified within 1 grade. Collapsing all grades into disease-negative status (grades 0 and 1) and disease-positive status (grades 2, 3, 4, and 5) yielded sensitivity of 95%, specificity of 100%, negative predictive value of 88%, and positive predictive value of 100%.

CONCLUSIONS

This study shows that MRI can be used to evaluate the articular cartilage covering osteochondral lesions of the talus with a high degree of accuracy and thus may aid in identifying patients who would benefit from definitive arthroscopic treatment.

Arthroscopic versus conservative treatment of osteochondritis dissecans of the knee: value of magnetic resonance imaging in therapy planning and follow-up

PURPOSE

Magnetic resonance imaging (MRI) was used to control the short-term outcome of osteochondritis dissecans (OCD) of the femoral condyle depending on conservative or surgical treatment at the beginning of therapy.

TYPE OF STUDY

Case series.

METHODS

Treatment planning for OCD depended on the stage on MRI when analyzing the appearance of the interface between parent bone and fragment on T1- and T2-weighted images. Twenty-seven patients received conservative treatment and 46 patients underwent arthroscopic surgery. After 20 to 24 months, patients were re-evaluated by MRI to assess the condition of bony fragment, parent bone, and interface so as to determine partial or complete remission, no change, or progression of OCD.

RESULTS

After conservative treatment, MRI showed partial or complete remission in 30% of patients and no change in 63%. Arthroscopic treatment led to remission in 37% and to no change in 57%. Progressive disintegration of OCD was found on MRI in 7% of conservatively treated patients and in 7% of the surgery patients. In 33.3% of the patients initially treated conservatively, it was decided to treat them arthroscopically because of ongoing, unacceptable clinical symptoms.

CONCLUSIONS

The rates of remission and progression were not significantly different between the groups. The patients' age was significantly correlated to the rate of consolidation. OCD in juveniles under 16 years of age followed a milder course than in adults.

Central pseudodefect of the talus: a potential ankle MR interpretation pitfall

PURPOSE

The purpose of our study was to outline the MR features of the central pseudodefect of the talus (a normal finding that can simulate an osteochondral lesion on ankle MR studies), assess the prevalence of the central pseudodefect of the talus, and provide insight into the origin of this misleading MR appearance.

METHOD

We retrospectively evaluated 31 ankle MR studies in 10 asymptomatic volunteers and 21 consecutive patients for the presence of the central pseudodefect of the talus. None of the patients had a history of trauma to the ankle. The signal, size, and shape of the pseudodefect were documented in each patient. The sagittal images were cross-referenced with the axial and coronal images in all patients in whom the central pseudodefect was identified.

RESULTS

Six volunteers (60%) and 13 patients (62%) showed a curvilinear band in the middle third of the talus on far medial sagittal images, consistent with the central pseudodefect of the talus. The band measured 8-15 x 3-8 mm (mean 11 x 4 mm) and was hypointense on T1 and STIR pulse sequences. In two cases, the pseudodefect was subchondral; in the rest, it was found a few millimeters below the articular surface. On cross-referenced axial and coronal images, the band corresponded to the talar insertion site of the deep tibiotalar fibers of the deltoid ligament.

CONCLUSION

The central pseudodefect of the talus is a common finding that is produced by the insertion of the tibiotalar fibers of the deltoid ligament into the talus. Familiarity with its appearance is necessary to avoid misinterpreting it as an osteochondral lesion of the talus.

Diagnostic imaging of osteochondrosis

This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. The imaging modalities discussed are survey radiography, contrast arthrography, linear tomography, ultrasound, computed tomography, scintigraphy and magnetic resonance. Survey radiography is the first choice imaging modality for diagnosing osteochondrosis dissecans in dogs. In cases where survey radiography fail to demonstrate a lesion other modalities such as scintigraphy, linear tomography, computed tomography, and magnetic resonance may be helpful. Survey radiography, contrast arthrography, computed tomography, and magnetic resonance may also provide additional information contributing to early diagnosis and treatment.