MR imaging-based diagnosis and classification of meniscal tears

Magnetic resonance (MR) imaging is currently the modality of choice for detecting meniscal injuries and planning subsequent treatment. A thorough understanding of the imaging protocols, normal meniscal anatomy, surrounding anatomic structures, and anatomic variants and pitfalls is critical to ensure diagnostic accuracy and prevent unnecessary surgery. High-spatial-resolution imaging of the meniscus can be performed using fast spin-echo and three-dimensional MR imaging sequences. Normal anatomic structures that can mimic a tear include the meniscal ligament, meniscofemoral ligaments, popliteomeniscal fascicles, and meniscomeniscal ligament. Anatomic variants and pitfalls that can mimic a tear include discoid meniscus, meniscal flounce, a meniscal ossicle, and chondrocalcinosis. When a meniscal tear is identified, accurate description and classification of the tear pattern can guide the referring clinician in patient education and surgical planning. For example, longitudinal tears are often amenable to repair, whereas horizontal and radial tears may require partial meniscectomy. Tear patterns include horizontal, longitudinal, radial, root, complex, displaced, and bucket-handle tears. Occasionally, meniscal tears can be difficult to detect at imaging; however, secondary indirect signs, such as a parameniscal cyst, meniscal extrusion, or linear subchondral bone marrow edema, should increase the radiologist's suspicion for an underlying tear. Awareness of common diagnostic errors can ensure accurate diagnosis of meniscal tears. Online supplemental material is available for this article.

MR Appearance and Clinical Significance of Changes in the Hip Muscles and Iliopsoas Tendon After Arthroscopic Iliopsoas Tenotomy in Symptomatic Patients

BACKGROUND

Iliopsoas tenotomy is a treatment for snapping hip. Does this surgical procedure change the surrounding muscle and tendon anatomy?

QUESTIONS/PURPOSES

This study seeks to evaluate the changes in the MR appearance of the hip muscles and iliopsoas tendon in patients following arthroscopic iliopsoas tenotomy.

METHODS

One hundred sixty-nine consecutive adults were evaluated after iliopsoas tenotomy at the lesser trochanter. Each MR exam was evaluated independently by three radiologists for muscle edema, atrophy (grade 0-4), compensatory hypertrophy, signal within the iliopsoas tendon (increased on T1 or T2 sequences), and iliopsoas tendon morphology (distorted or disrupted) above, at, and below the iliopectineal eminence. A finding was considered positive if reported by two or three of the radiologists.

RESULTS

Twenty subjects met the inclusion criteria. Muscle edema was present in 15% (3/20) of subjects within the iliacus, psoas, and quadratus femoris. Atrophy was observed in the following muscles: iliacus 85% (17/20), psoas 75% (15/20), quadratus femoris 10% (2/20), rectus femoris 5% (1/20), vastus lateralis 5% (1/20), and gluteus maximus 25% (5/20). There was no compensatory hypertrophy. Ninety percent (18/20) had increased T1 and 10% (2/20) had increased T2 signal within the iliopsoas tendon. Thirty-five percent (7/20) of the iliopsoas tendons was disrupted and 85% (17/20) was distorted, most commonly below the iliopectineal eminence.

CONCLUSION

The majority of postoperative symptomatic patients has atrophy of the iliacus and psoas muscles and distortion and disruption of the iliopsoas tendon and should be recognized as a normal imaging appearance following iliopsoas tendon release.

High resolution ultrasound features of prostatic rib metastasis: a prospective feasibility study with implication in the high-risk prostate cancer patient

OBJECTIVE

In a prior study, high resolution ultrasound (US) was shown to be accurate for evaluating rib metastasis detected on bone scan. However, that study did not address the specific US appearance typical of osteoblastic rib metastasis. Our objective was to determine the specific US imaging appearance of osteoblastic prostate carcinoma rib metastasis using osteolytic renal cell carcinoma rib metastasis as a comparison group.

MATERIALS AND METHODS

The Institutional Review Board approval and informed consent were obtained for this prospective feasibility study. We performed high resolution US of 16 rib metastases in 4 patients with prostate carcinoma metastases and compared them to 8 rib metastases in 3 male patients with renal cell carcinoma. All patients had rib metastases proven by radiographs and computed tomography (CT). High resolution US scanning was performed by a musculoskeletal radiologist using a 12-5 MHz linear-array transducer. Transverse and longitudinal scans were obtained of each rib metastasis.

RESULTS

All 16 prostate carcinoma metastases demonstrated mild cortical irregularity of the superficial surface of the rib without associated soft tissue mass, cortical disruption, or bone destruction. 7 of 8 (88%) renal cell carcinoma rib metastases demonstrated cortical disruption or extensive bone destruction without soft tissue mass. One of 8 (12%) renal cell carcinoma rib metastases demonstrated only minimal superficial cortical irregularity at the site of a healed metastasis.

CONCLUSION

Osteoblastic prostate carcinoma rib metastases have a distinctive appearance on US. Our success in visualizing these lesions suggests that US may be a useful tool to characterize isolated rib abnormalities seen on a bone scan in high-risk prostate cancer patients who are being evaluated for curative surgery or radiation treatment.

Evaluation of the menisci of the knee joint using three-dimensional isotropic resolution fast spin-echo imaging: diagnostic performance in 250 patients with surgical correlation

OBJECTIVE

To compare the diagnostic performance of FSE-Cube, a three-dimensional isotropic resolution intermediate-weighted fast spin-echo sequence, with a routine magnetic resonance (MR) protocol at 3.0 T for detecting surgically confirmed meniscal tears of the knee joint in a large patient population.

METHODS

FSE-Cube was added to a routine MR protocol performed at 3.0 T on 250 patients who underwent subsequent knee arthroscopy. Three radiologists independently used FSE-Cube during one review and the routine MR protocol during a second review to detect medial and lateral meniscal tears. Using arthroscopy as the reference standard, the sensitivity and specificity of FSE-Cube and the routine MR protocol for detecting meniscal tears were determined for all readers combined. McNemar's tests were used to compare diagnostic performance between FSE-Cube and the routine MR protocol.

RESULTS

FSE-Cube and the routine MR protocol had similar sensitivity (95.5%/95.3% respectively, P = 0.94) and similar specificity (69.8%/74.0% respectively, P = 0.10) for detecting 156 medial meniscal tears. FSE-Cube had significantly lower sensitivity than the routine MR protocol (79.4%/85.0% respectively, P < 0.05) but similar specificity (83.9%/82.2% respectively, P = 0.37) for detecting 89 lateral mensical tears. For lateral meniscal tears, FSE-Cube had significantly lower sensitivity (P < 0.05) than the routine MR protocol for detecting 19 root tears but similar sensitivity (P = 0.17-1.00) for detecting all other tear locations and types.

CONCLUSION

FSE-Cube had diagnostic performance similar to a routine MR protocol for detecting meniscal tears except for a significantly lower sensitivity for detecting lateral meniscal tears, which was mainly attributed to decreased ability to identify lateral meniscus root tears.

Musculoskeletal mnemonics: differentiating features

Mnemonics are often used in musculoskeletal radiology to help radiologists remember long differential diagnoses. However, unless the specific appearance of each entity on a differential is also recalled, mnemonics become useless. This article presents 8 mnemonics with their corresponding differential diagnoses and distinguishing features. Bubbly lucent lesions of bone are recalled with the FEGNOMASHIC mnemonic, but when only lucent lesions of the diaphysis are included, a more appropriate mnemonic is FEMALE. The lucent lesions of bone differentials often can be narrowed based on specific characteristics of the lesion but radiographic findings elsewhere and clinical information often help. Osseous metastases may present as lucent or sclerotic lesions; when sclerotic, the differential is best remembered with the mnemonic 5 "BEES" Like Pollen. The mnemonic for Wormian bones is PORKCHOPS. The Wormian bones in most of these entities are indistinguishable, so one must rely on radiographic findings outside the skull for diagnosis. By contrast, differentiating causes of acro-osteolysis is often possible with findings seen only on the hand radiographs; the mnemonic for acro-osteolysis is RADSHIP. In skeletally immature patients with frayed metaphyses, the mnemonic is CHARMS. Although the appearance of the fraying is seldom diagnostic, findings in the adjacent portions of the long bones may be characteristic. FETISH is the mnemonic used to remember the entities for the differential diagnosis of vertebra plana. Age of the patient, clinical history, and findings in the adjacent spine often help to provide the specific diagnosis. Nearly all the entities on the differential diagnosis for distal clavicle erosion (mnemonic: SHIRT Pocket) are included in other differentials in this article.

Magnetic resonance imaging in traumatic hip subluxation

Athletic traumatic hip subluxations are rare. Classic radiographic features have been well described. This case highlights the potential pitfalls of immediate magnetic resonance imaging. Femoral head contusions and acetabular rim fractures are common associated findings usually apparent with magnetic resonance imaging (MRI). However, in this case an MRI done 3 hours post injury failed to show any edema in either location, making the appearance of these findings on subsequent MRIs difficult to interpret. An acute MRI more than 48 hours post injury may have been more helpful.

Knee joint: comprehensive assessment with 3D isotropic resolution fast spin-echo MR imaging--diagnostic performance compared with that of conventional MR imaging at 3.0 T

PURPOSE

To determine whether a three-dimensional isotropic resolution fast spin-echo sequence (FSE-Cube) has similar diagnostic performance as a routine magnetic resonance (MR) imaging protocol for evaluating the cartilage, ligaments, menisci, and osseous structures of the knee joint in symptomatic patients at 3.0 T.

MATERIALS AND METHODS

This prospective, HIPAA-compliant, institutional review board-approved study was performed with a waiver of informed consent. FSE-Cube was added to the routine 3.0-T MR imaging protocol performed in 100 symptomatic patients (54 male patients with a median age of 32 years and 46 female patients with a median age of 33 years) who subsequently underwent arthroscopic knee surgery. All MR imaging studies were independently reviewed twice by two musculoskeletal radiologists. During the first review, the routine MR imaging protocol was used to detect cartilage lesions, ligament tears, meniscal tears, and bone marrow edema lesions. During the second review, FSE-Cube with multiplanar reformations was used to detect these joint abnormalities. With arthroscopic results as the reference standard, the sensitivity and specificity of FSE-Cube and the routine MR imaging protocol in the detection of cartilage lesions, anterior cruciate ligament tears, and meniscal tears were calculated. Permutation tests were used to compare sensitivity and specificity values.

RESULTS

FSE-Cube had significantly higher sensitivity (P = .039) but significantly lower specificity (P = .003) than the routine MR imaging protocol for detecting cartilage lesions. There were no significant differences (P = .183-.999) in sensitivity and specificity between FSE-Cube and the routine MR imaging protocol in the detection of anterior cruciate ligament tears, medial meniscal tears, or lateral meniscal tears. FSE-Cube depicted 96.2% of medial collateral ligament tears, 100% of lateral collateral ligament tears, and 85.3% of bone marrow edema lesions identified on images obtained with the routine MR imaging protocol.

CONCLUSION

FSE-Cube has similar diagnostic performance as a routine MR imaging protocol for detecting cartilage lesions, cruciate ligament tears, collateral ligament tears, meniscal tears, and bone marrow edema lesions within the knee joint at 3.0 T.

Correlation of MRI findings with clinical findings of trochanteric pain syndrome

OBJECTIVE

Greater trochanter pain syndrome due to tendinopathy or bursitis is a common cause of hip pain. The previously reported magnetic resonance (MR) findings of trochanteric tendinopathy and bursitis are peritrochanteric fluid and abductor tendon abnormality. We have often noted peritrochanteric high T2 signal in patients without trochanteric symptoms. The purpose of this study was to determine whether the MR findings of peritrochanteric fluid or hip abductor tendon pathology correlate with trochanteric pain.

MATERIALS AND METHODS

We retrospectively reviewed 131 consecutive MR examinations of the pelvis (256 hips) for T2 peritrochanteric signal and abductor tendon abnormalities without knowledge of the clinical symptoms. Any T2 peritrochanteric abnormality was characterized by size as tiny, small, medium, or large; by morphology as feathery, crescentic, or round; and by location as bursal or intratendinous. The clinical symptoms of hip pain and trochanteric pain were compared to the MR findings on coronal, sagittal, and axial T2 sequences using chi-square or Fisher's exact test with significance assigned as p < 0.05.

RESULTS

Clinical symptoms of trochanteric pain syndrome were present in only 16 of the 256 hips. All 16 hips with trochanteric pain and 212 (88%) of 240 without trochanteric pain had peritrochanteric abnormalities (p = 0.15). Eighty-eight percent of hips with trochanteric symptoms had gluteus tendinopathy while 50% of those without symptoms had such findings (p = 0.004). Other than tendinopathy, there was no statistically significant difference between hips with or without trochanteric symptoms and the presence of peritrochanteric T2 abnormality, its size or shape, and the presence of gluteus medius or minimus partial thickness tears.

CONCLUSIONS

Patients with trochanteric pain syndrome always have peritrochanteric T2 abnormalities and are significantly more likely to have abductor tendinopathy on magnetic resonance imaging (MRI). However, although the absence of peritrochanteric T2 MR abnormalities makes trochanteric pain syndrome unlikely, detection of these abnormalities on MRI is a poor predictor of trochanteric pain syndrome as these findings are present in a high percentage of patients without trochanteric pain.

Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material

OBJECTIVE

Several previous studies reported that the signal contacting the meniscal surface in a recurrent tear on MR arthrography had intensity equal to that of intraarticular contrast material. Because we failed to diagnose recurrent tears using this criterion, we reviewed our knee MR arthrograms in patients who had prior meniscal surgery.

CONCLUSION

On knee MR arthrograms, the signal contacting the surface of a recurrent meniscal tear may be equal to or less than that of adjacent intraarticular gadolinium contrast material.

Use of the "two-slice-touch" rule for the MRI diagnosis of meniscal tears

OBJECTIVE

We reviewed our experience with knee MRI to determine if using the "two-slice-touch" rule increased our positive predictive value for diagnosing meniscal tears. This rule classifies a meniscus as torn if there are two or more MR images with abnormal findings and as possibly torn if there is only one MR image with an abnormal finding. We also compared our sensitivity and specificity using fast spin-echo imaging with previously reported studies.

MATERIALS AND METHODS

We reviewed the medical records of 174 patients who had knee MR examinations and correlative knee arthroscopy to determine our accuracy when we diagnosed menisci as torn, possibly torn, or intact using knee arthroscopy as the gold standard.

RESULTS

Our positive predictive value increased from 91% to 94% (p = 0.37) for medial meniscal tears and from 83% to 96% (p = 0.02) for lateral meniscal tears when using the two-slice-touch rule compared with the standard criterion of diagnosing a meniscus as torn if one or more images are abnormal. When using the standard criterion, we had 95% sensitivity and 85% specificity for diagnosing medial meniscal tears and 77% sensitivity and 89% specificity for diagnosing lateral meniscal tears.

CONCLUSION

When using the two-slice-touch rule, we had an increased positive predictive value for diagnosing menisci as torn, which was statistically significant for the lateral meniscus. Our accuracy using the standard criterion with fast spin-echo imaging was comparable to that reported in previous studies with spin-echo imaging.

Sonography of the iliopsoas tendon and injection of the iliopsoas bursa for diagnosis and management of the painful snapping hip

OBJECTIVE

The purpose of this study was to compare sonographic evaluations of patients referred with suspected snapping of their iliopsoas tendon with the pain relief achieved from anesthetic injection of the iliopsoas bursa, and with the subsequent surgical outcome. This study also assessed the effectiveness of Kenalog injection into the iliopsoas bursa for long-term pain relief.

PATIENTS AND METHODS

Dynamic and static sonography was performed in 40 patients with clinically diagnosed snapping hips. The iliopsoas bursa was injected with Bupivicaine and Lidocaine in the first 22 patients, and an additional 1 ml Kenalog-40 was added to this mixture in the last 18 patients. We compared the static and dynamic sonographic findings with change in the patients' level of pain at 2 days after anesthetic injection. The sonographic findings and response to anesthetic injection were also compared to the response to Kenalog injection and the results of any subsequent surgery.

RESULTS

Static sonography of the iliopsoas tendon was normal in 38 patients, and detected iliopsoas bursitis in one patient and iliopsoas tendinopathy in another. Snapping of the iliopsoas tendon was observed using dynamic sonography in 9 of the 40 patients. Following anesthetic injection of the iliopsoas bursa, 29 patients had complete or partial pain relief, and 11 patients had no pain relief. Eight of the nine patients with a snapping iliopsoas tendon had complete or partial pain relief from the bursal injection. Twelve of the 29 patients with pain relief after anesthetic injection later had an arthroscopic iliopsoas tendon release, and all of these 12 patients had a good postoperative result. Of the 18 patients who had Kenalog-40 injected into the iliopsoas bursa and did not have iliopsoas surgery, 16 had sustained pain relief following the injection.

CONCLUSIONS

Patients with groin pain and a clinically suspected snapping iliopsoas tendon can benefit from injection into the iliopsoas bursa even if the snapping tendon is not visualized sonographically. The use of a corticosteroid may provide long-term pain relief, and pain relief after injection is a predictor of good outcome after surgical release of the iliopsoas tendon.

The role of ultrasound in the evaluation of sports medicine injuries of the upper extremity

The two major imaging modalities used for assessment of soft tissue injuries are ultrasound and MRI. Although ultrasound of the extremities is used only to a limited extent in the United States, it is widely used in many other countries for evaluation of extremity injuries. This article first considers the advantages and disadvantages of MRI and ultrasound. Understanding these differences will help the reader understand the role of ultrasound as compared with MRI in evaluating upper extremity injuries. The uses of ultrasound for evaluating sports medicine injuries in specific regions of the upper extremity are then reviewed. Where the data are available, the reported accuracy of ultrasound is compared with MRI for each type of injury.

Radiographic findings of osteoarthritis versus arthroscopic findings of articular cartilage degeneration in the tibiofemoral joint

PURPOSE

To retrospectively correlate radiographic findings of osteoarthritis of the tibiofemoral joint with arthroscopic findings of articular cartilage degeneration within the tibiofemoral joint in patients with chronic knee pain.

MATERIALS AND METHODS

The study was performed in compliance with HIPAA regulations. Approval from an institutional review board and a waiver of informed consent were obtained. The study group consisted of 125 patients with osteoarthritis of the tibiofemoral joint (66 men, 59 women; age range, 35-77 years; average age, 52 years) and 25 patients of similar age (14 men, 11 women; age range, 36-69 years; average age, 50 years) with no osteoarthritis of the tibiofemoral joint. All patients underwent standing anteroposterior radiography of the knee prior to arthroscopic knee surgery. Each articular surface of the tibiofemoral joint was graded at arthroscopy. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the medial and lateral compartments of the tibiofemoral joint were determined.

RESULTS

The sensitivity of marginal osteophytes, joint space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration was 67%, 46%, 16%, and 10%, respectively, for the medial compartment and 49%, 7%, 6%, and 3%, respectively, for the lateral compartment. The specificity of marginal osteophytes, joint space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration was 73%, 95%, 100%, and 100%, respectively, for the medial compartment and 81%, 100%, 100%, and 100%, respectively, for the lateral compartment.

CONCLUSION

Marginal osteophytes were the most sensitive radiographic feature for the detection of osteoarthritis of the tibiofemoral joint. Joint space narrowing, subchondral sclerosis, and subchondral cysts were less sensitive radiographic features of osteoarthritis and rarely occurred in the absence of associated osteophyte formation.

MRI findings of osteochondritis dissecans of the capitellum with surgical correlation

OBJECTIVE

Few studies have described the MRI findings of osteochondritis dissecans of the capitellum. Our objective was to describe the MRI findings of 10 patients with osteochondritis dissecans of the capitellum and to correlate the imaging findings with surgical findings of stability and instability.

CONCLUSION

The MRI findings of unstable and stable osteochondritis dissecans of the capitellum are similar to the findings described for osteochondritis dissecans of the femoral condyles and talar dome. Unstable osteochondritis dissecans lesions are surrounded by a rim of high signal intensity or a fluid-filled cyst on T2-weighted images. Stable osteochondritis dissecans lesions show no surrounding signal abnormality on T2-weighted images.

Lumbar Radiculopathy: Treatment with Selective Lumbar Nerve Blocks—Comparison of Effectiveness of Triamcinolone and Betamethasone Injectable Suspensions

PURPOSE

To retrospectively determine if there is a difference in the effectiveness of triamcinolone acetonide injectable suspension versus betamethasone sodium phosphate and betamethasone acetate injectable suspension in the treatment of radiculopathy and low back pain with selective lumbar nerve blocks.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and was HIPAA compliant; informed consent was not required. Charts and self-reported pain score evaluations were retrospectively reviewed in 114 patients (56 men, 58 women; age range, 36-84 years; mean age, 60 years) treated for radiculopathy from 1997 to 2003 with 130 selective lumbar nerve blocks with triamcinolone or betamethasone. Perineural location was confirmed with fluoroscopic guidance. Forty-nine patients received a mixture of 1 mL of the triamcinolone, 40 mg/mL, and 1 mL of 0.5% bupivacaine hydrochloride. Eighty-one patients received a mixture of 1 mL of the betamethasone, 6 mg/mL, and 1 mL of 0.5% bupivacaine hydrochloride. Patients completed standardized pain evaluation sheets and compared their pain with baseline levels during 14 days after injection. Fisher exact test was used for data analysis.

RESULTS

From day 0 to 1 after the procedure, there was no statistically significant difference in improvement in low back pain and lower extremity pain between groups. On day 3, 42% of triamcinolone recipients and 58% of betamethasone recipients demonstrated improvement in low back pain (P = .04, Fisher exact test), whereas 55% of triamcinolone recipients and 57% of betamethasone recipients had lower extremity pain improvement (P = .33). On day 7, 45% of triamcinolone recipients and 58% of betamethasone recipients had improvement in low back pain (P = .38), whereas 52% of triamcinolone recipients and 57% of betamethasone recipients had improvement in lower extremity pain (P = .69). On day 14, 42% of triamcinolone recipients and 53% of betamethasone recipients had improvement in low back pain (P = .26), whereas 49% of triamcinolone recipients and 55% of betamethasone recipients had improvement in lower extremity pain (P = .69).

CONCLUSION

Selective nerve root blocks with betamethasone and triamcinolone reduced low back pain and lower extremity pain, although there was no significant difference in effectiveness between the two.

Is intra-articular pathology associated with MCL edema on MR imaging of the non-traumatic knee?

OBJECTIVE

Edema surrounding the medial collateral ligament (MCL) is seen on MR imaging in patients with MCL injuries and in patients with radiographic osteoarthritis in the non-traumatic knee. Because we noted MCL edema in patients without prior trauma or osteoarthritis, we studied the association between intra-articular pathology and MCL edema in patients without knee trauma.

DESIGN AND PATIENTS

We evaluated the MR examinations of 247 consecutive patients (121 male, 126 female with a mean age of 44 years) without recent trauma for the presence of edema surrounding the MCL, meniscal and ACL tears, medial meniscal extrusion, medial compartment chondromalacia, and osteoarthritis. The percentages of patients illustrating MCL edema with and without each type of pathology were compared using Fisher's exact test to determine if there was a statistically significant association.

RESULTS

We found MCL edema in 60% of 247 patients. MCL edema was present in 67% of patients with medial meniscal tears, 35% with lateral meniscal tears, 100% with meniscal extrusion of 3 mm or more, 78% with femoral chondromalacia, 82% with tibial chondromalacia, and 50% with osteoarthritis. The percentage of patients with edema increased with the severity of the chondromalacia. These associations were all statistically significant (p <0.02). The mean age of those with MCL edema was 49.7 years compared with 34.9 years without MCL edema ( p <0.001). Patient gender and ACL tear did not correlate with MCL edema. Nine (4%) of the 247 patients had MCL edema without intra-articular pathology. None of these 9 patients had MCL tenderness or joint laxity on physical examination.

CONCLUSIONS

We confirmed that MCL edema is associated with osteoarthritis, but is also associated with meniscal tears, meniscal extrusion, and chondromalacia. In addition, MCL edema can be seen in patients without intra-articular pathology, recent trauma or MCL abnormality on physical examination.

Radiography of the elbow for evaluation of patients with osteochondritis dissecans of the capitellum

OBJECTIVE

This study was performed to determine the ability of a routine radiographic examination of the elbow to detect osteochondritis dissecans of the capitellum and associated intra-articular loose bodies.

DESIGN AND PATIENTS

The study group consisted of 15 patients with osteochondritis dissecans of the capitellum confirmed by surgery or magnetic resonance imaging. Seven of the 15 patients had associated intra-articular loose bodies confirmed by surgery. All 15 patients had anteroposterior and lateral radiographs and magnetic resonance imaging of their symptomatic elbow. Nine of the 15 patients had subsequent elbow surgery. We reviewed the original interpretations of the radiographic examinations of the elbow of all 15 patients to determine whether osteochondritis dissecans of the capitellum and associated intra-articular loose bodies had been identified prospectively. We also reviewed the elbow radiographs of all 15 patients to determine whether osteochondritis dissecans of the capitellum and associated intra-articular loose bodies could be identified retrospectively.

RESULTS

Osteochondritis dissecans of the capitellum was detected during the initial interpretations of the radiographic examinations of the elbow in seven of 15 patients. Osteochondritis dissecans of the capitellum was detected during retrospective review of the elbow radiographs in 10 of 15 patients. Intra-articular loose bodies were detected during the initial interpretations of the radiographic examinations of the elbow in three of seven patients. Intra-articular loose bodies were detected during retrospective review of the elbow radiographs in four of seven patients.

CONCLUSIONS

A routine radiographic examination of the elbow has limited sensitivity for detecting osteochondritis dissecans of the capitellum and associated intra-articular loose bodies.

MR Imaging and MR Arthrography for Diagnosis of Recurrent Tears in the Postoperative Meniscus

The accuracy, pitfalls, and limitations of magnetic resonance (MR) imaging for diagnosing a tear in the nonoperated knee are well known. However, the diagnosis of a recurrent tear can be more difficult in the postoperative meniscus. Resection or meniscal repair results in postoperative changes that can mimic a recurrent tear. To serve as a foundation, the techniques of treatment for meniscal tears are reviewed. This is followed by a detailed review of the literature on the accuracy of diagnosis of a recurrent meniscal tear using MR imaging and MR arthrography. Finally, recommendations are given as to the circumstances in which MR imaging or MR arthrography should be used for evaluation of the postoperative meniscus.

Magnetic resonance imaging findings in patients with medial epicondylitis

OBJECTIVE

To compare the MR imaging findings of 13 patients with clinically diagnosed medial epicondylitis with the MR imaging findings of 26 patients of similar age with no clinical evidence of medial epicondylitis.

DESIGN AND PATIENTS

The study group consisted of 13 patients with clinically diagnosed medial epicondylitis. The control group consisted of 26 patients of similar age with no clinical evidence of medial epicondylitis. The medical records and MR imaging findings of these patients were retrospectively reviewed by two fellowship-trained musculoskeletal radiologists.

RESULTS

Eleven of the 13 patients in the study group had thickening and increased signal intensity of the common flexor tendon on both T1-weighted and T2-weighted images. The remaining two patients in the study group had soft tissue edema around a normal-appearing common flexor tendon. Twenty-one of the 26 patients in the control group had a normal-appearing common flexor tendon on MR imaging. Three patients in the control group had a thickened common flexor tendon which was of intermediate signal intensity on T1-weighted images but of uniform low signal intensity on T2-weighted images. Two patients in the control group had a thickened common flexor tendon which was of intermediate signal intensity on both T1-weighted and T2-weighted images. None of the patients in the control group had soft tissue edema around the common flexor tendon.

CONCLUSION

MR imaging findings of patients with clinically diagnosed medial epicondylitis included thickening and increased T1 and T2 signal intensity of the common flexor tendon and soft tissue edema around the common flexor tendon. The presence of intermediate to high T2 signal intensity or high T2 signal intensity within the common flexor tendon and the presence of paratendinous soft tissue edema were the most specific findings of medial epicondylitis on MR imaging.

Efficacy of epidural injections of Kenalog and Celestone in the treatment of lower back pain

OBJECTIVE

Epidural corticosteroid injections have been used extensively to treat lower back pain, but the relative effectiveness of one corticosteroid versus another has never been reported in a large patient series. We retrospectively reviewed 597 patients who had epidural corticosteroid injections to determine any difference in Kenalog or Celestone efficacy.

MATERIALS AND METHODS

We reviewed charts and self-reported pain score evaluations of 597 patients who received either Kenalog or Celestone Soluspan as an epidural injection for the treatment of lower back pain from 1997 to 2002 at our university hospital and affiliated Veterans Affairs hospital. Kenalog was used for the initial 2 years and Celestone was used for the next 3 years. Fluoroscopic guidance was used to confirm epidural location, and each patient was injected with a mixture of 5 mL of 0.5% preservative-free lidocaine and 2 mL of either Kenalog 40 mg/mL (triamcinolone acetonide injectable suspension) or Celestone Soluspan 6 mg/mL (betamethasone sodium phosphate and betamethasone acetate injectable suspension). Each patient was given a standardized pain evaluation sheet that used an 11-point scale for initial pain severity. Scoring of pain compared with baseline during the following 14 days was based on a 5-point scale of pain improvement or worsening.

RESULTS

On days 0-3 after the procedure, no statistical significance in improvement of lower back and buttock pain was seen between groups. On day 7, 59% of Celestone recipients and 73% of Kenalog recipients showed improvement in lower back pain (p = 0.002, Pearson's chi-square test), and 58% of Celestone recipients and 75% of Kenalog recipients had improvement in leg or buttock pain (p < 0.001). On day 14, 54% of Celestone recipients and 71% of Kenalog recipients showed improvement in lower back pain (p < 0.001), and 54% of Celestone recipients and 71% of Kenalog recipients had improvement in leg or buttock pain (p < 0.001).

CONCLUSION

The epidural injection of Celestone Soluspan and Kenalog reduced lower back and radicular pain in more than half the patients, although Kenalog reduced pain in a significantly larger number of patients than Celestone Soluspan at 1 and 2 weeks after injection.

Dynamic sonography with valgus stress to assess elbow ulnar collateral ligament injury in baseball pitchers

Sonography is a valuable method for imaging superficial tendons and ligaments. The ability to obtain comparison images easily with dynamic stress allows assessment of ligament and tendon integrity. We studied the medial elbow joints of two baseball pitchers using MR imaging and dynamic sonography. Both sonography and MR imaging identified the ulnar collateral ligament tears. Dynamic sonography uniquely demonstrated the medial joint instability.

Usefulness of two indirect MR imaging signs to diagnose lateral meniscal tears

OBJECTIVE

We determined whether using two recently described indirect MR imaging signs would improve the sensitivity of diagnosis of lateral meniscal tears.

MATERIALS AND METHODS

We identified 121 consecutive patients who had undergone knee MR imaging and knee arthroscopy. Their MR imaging examinations were evaluated for the conventional criteria of a meniscal tear (meniscal distortion or intrameniscal signal contacting the surface) and the two new signs (presence of an abnormal popliteomeniscal fascicle and posterolateral pericapsular edema). These observations were correlated with the arthroscopic findings, which were used as the gold standard.

RESULTS

Thirty-two (89%) of the 36 torn lateral menisci had two or more images with distortion or signal contacting the surface. Three torn menisci and eight intact menisci had one image with distortion or surface signal. Only one of 75 menisci without distortion or surface signal was torn. An abnormal superior fascicle was highly associated (p < 0.001) with lateral meniscal tears but was not specific for a tear because three of the 14 menisci with abnormal fascicles were not torn. Posterolateral pericapsular edema was not associated with a lateral meniscal tear (p = 0.06). Using an abnormal fascicle as an additional criterion improved the sensitivity from 89% to 94%, but the difference was not statistically significant.

CONCLUSION

We confirmed that an abnormal fascicle is highly associated with a lateral meniscal tear but found that posterolateral pericapsular edema was not associated with lateral meniscal tears. Identifying an abnormal fascicle did not significantly improve the sensitivity of diagnosis of a lateral meniscal tear.