Subchondral Signal Research Articles

Normal subchondral high T2 signal on MRI mimicking sacroiliitis in children: frequency, age distribution, and relationship to skeletal maturity.

To determine patterns of variation of subchondral T2 signal changes in pediatric sacroiliac joints (SIJ) by location, age, sex, and sacral apophyseal closure. MRI of 502 SIJ in 251 children (132 girls), mean age 12.4years (range 6.1-18.0), was obtained with parental informed consent. One hundred twenty-seven out of 251 had asymptomatic joints and were imaged for non-rheumatologic reasons, and 124 had low back pain but no sign of sacroiliitis on initial clinical MRI review. After calibration, three subspecialist radiologists independently scored subchondral signal changes on fat-suppressed fluid-sensitive sequences from 0 to 3 in 4 locations, and graded the degree of closure of sacral segmental apophyses. Associations between patient age, sex, signal changes, and apophyseal closure were analyzed. Rim-like subchondral increased T2 signal or "flaring" was much more common at sacral than iliac SIJ margins (72% vs 16%, p< 0.001) and was symmetrical in > 90% of children. Iliac flaring scores were always lower than sacral, except for 1 child. Signal changes decreased as sacral apophyses closed, and were seen in < 20% of subjects with fully closed apophyses. Signal changes were more frequent in boys, and peaked in intensity later than for girls (ages 8-12 vs. 7-10). Subchondral signal in iliac crests was high throughout childhood and did not correlate with other locations. Subchondral T2 "flaring" is common at SIJ of prepubertal children and is generally sacral-predominant and symmetrical. Flaring that is asymmetrical, greater in ilium than sacrum, or intense in a teenager with closed apophyses, is unusual for normal children and raises concern for pathologic bone marrow edema. • A rim of subchondral high T2 signal is commonly observed on MRI at pediatric sacroiliac joints, primarily on the sacral side before segmental apophyseal closure, and should not be confused with pathology. • Unlike subchondral signal changes elsewhere, high T2 signal underlying the iliac crest apophyses is a near-universal normal finding in children that usually persists throughout adolescence. • The following patterns are unusual in normal children and are suspicious for pathology: definite iliac flaring, iliac flaring more intense than sacral flaring, left-right difference in flaring, definite flaring of any pattern in teenagers after sacral apophyseal closure.

The Role of MRI in Diagnosing Biceps Chondromalacia

Objectives:Sisterman described the “Biceps Footprint”, Castagna et al reported on “Chondral Imprints,” and Kuhn et al identified “Humeral Head Abrasions.”[1],[2],[3] These can be considered types of biceps chondromalacia (BCM), as we define it, which is an attritional lesion on the humeral head, caused by abrasion of the LHBT over time. BCM occurs in two distinct types: “Junctional” or “Medial”. Junctional BCM (Figure 1) is found along the articular margin of the humeral head where the biceps tendon exits the joint. Medial BCM (Figure 2) is found on the anteromedial portion of the articular surface and may result from chronic “incarceration” of the LHBT between the humeral head and glenoid, a dynamic lesion elicited by the arthroscopic active compression test.[4] The pre-operative assessment of BCM has never been addressed. The purpose of the study was to evaluate the ability of pre-operative MRI to diagnose BCM.Methods:A retrospective review was conducted looking at preoperative MRI and intra-operative digital photos comparing three groups: 1) patients operated on for painful BLC lesions with demonstrable BCM seen at surgery (n=34); 2) patients operated on for painful BLC lesions without demonstrable BCM seen at surgery (n=21); and 3) patients without clinical BLC pain operated on for shoulder instability (n=29), who were used as a control group against the BLC pain groups. Groups one and two were age matched, both with a mean age of 42 years, while the average age of patients in group 3 was 29. The MRI's were scored once by an orthopedic surgeon, who graded based on presence or absence of a visible lesion, and again by an experienced radiologist, who blindly and independently scored the MRI's based on chondral loss, bone marrow edema, subchondral signal change, and tendinosis or fraying of the biceps tendon.Results:In group 1, 85% of patients had cartilage loss, 64% had subchondral signal changes, and 85% had a pathological signal in the proximal biceps. In group 2, 86% of patients had cartilage loss, 52% had subchondral signal changes, and 81% had a pathological signal in the proximal biceps, even though no BCM was grossly identified at surgery. In group 3, however, only 51% of patients had cartilage loss, 34% subchondral signal change, and 44% pathological signal in the proximal biceps tendon. Groups 1 and 2 were statistically similar to each other, but varied significantly when compared to group 3. This was particularly true with regard to cartilage loss (p=0.004), signal in proximal biceps (p=0.001), and subchondral signal change (p=0.041).Conclusion:MRI is a valuable pre-operative assessment tool that can alert the surgeon to the presence of BCM even if such a lesion has not yet become grossly apparent at arthroscopy. BCM characteristics on MRI include abnormal signal in the proximal biceps, subchondral bone, and cartilage loss. MRI findings consistent with BCM should prompt the physician to consider the biceps as the source of the patient's pain. This is especially relevant when differentiating between a labral tear and the LHBT as inciting pathology. It should be noted, for example, that Provencher et al reported 28% of patients with type II SLAP tears, ultimately underwent a biceps surgery for persistent symptoms. [1] This study adds to our collective diagnostic acumen related to the biceps labral complex and highlights the utility of preoperative MRI.

Erratum to: MRI and CT evaluations of an invented bioglue in experimentally induced articular cartilage defects in rabbits

Articular cartilage defect is a condition leading to osteoarthritis of the joints if they remain unhealed or untreated. Some available surgical adhesives are used to adhere the wandering cartilaginous particle and avoid further joint damage. Healing as well as adhering properties of different substances has always been a topic of concern. Magnetic resonance imaging (MRI) and computed tomography (CT) are used to diagnose the condition. This is an effort to evaluate the healing and adhering properties of a newly invented bioglue, both with MRI and CT. Sixty adult, Dutch, male rabbits used for this study were divided into five equal groups (A–E). The groups were A: (a harvested graft was adhered to 4-mm diameter defects), B: (same as group A with 6-mm diameter defect), C: (4- and 6-mm defects were made in either knee or the graft sutured), D: (only defects were created and remained intact), and E: (defects were created and filled with bioglue). The groups were imaged 30 and 60 days postoperation. CT results showed that there was no significant difference in spur formation between groups, while focal osteopenia was higher in groups A, B, C (30 days), and D (30 days). Sclerosis was lower in group E than other groups. MRI showed subchondral signal change and joint effusion to be lower in group E than other groups. The invented bioglue in the present work reduced OA signs on CT and MRI and had no side effects.

Anomalies of the Discoid Medial Meniscus

Anomalies associated with a discoid medial meniscus have been described. However, the clinical relevance of these anomalies has not been previously reported. Therefore, we report the clinical relevance of some of these anomalies based on our experience with a 21-year-old soldier with a 3-month history of medial right knee pain. Magnetic resonance imaging (MRI) revealed bilateral discoid medial menisci, cupping of the medial tibial plateau, and an abnormal anteroinferior transposition of the anterior horn of the meniscus. Partial meniscectomy was performed in the usual manner and the meniscus reshaped, including its anteromedial corner.

MRI follow-up of subchondral signal abnormalities in a selected group of chronic low back pain patients

MRI follow-up of subchondral signal abnormalities in a selected group of chronic low back pain patients

Osteochondral lesion of the fifth metatarsal head in a triathlete

Osteochondral lesions (OCLs) are rare joint disorders, typically found in the larger joints of the body and less so in smaller joints (J Bone Joint Surg Am 41-A:988-1020, 1959; Arthroscopy 6(3):190-197, 1990; Clin Orthop Relat Res 148:245-253, 1980). Although their specific cause is subject to frequent debate, they are often caused by trauma with subsequent compromise of the articular cartilage (Arthroscopy 6(3):190-197, 1990; J Bone Joint Surg Am 78(3):439-456, 1996). Symptoms are typically attributable to a mechanical defect, either of the bony defect or a flap of cartilage. The current case report describes an osteochondral lesion of the head of the fifth metatarsal which is a heretofore unreported location. Magnetic resonance imaging (MRI) of the lesion revealed a notable subchondral bone signal change, indicating a possible synovial fluid pressure phenomenon rather than a mechanical defect.

MRI follow-up of subchondral signal abnormalities in a selected group of chronic low back pain patients

Subchondral signal abnormalities have been suggested to play an important role in chronic low back pain (LBP) syndromes. Their natural course is not well known. In this study the morphology and natural course of isolated subchondral signal abnormalities in the lumbosacral spine were analyzed with MRI. Twenty-four chronic LBP patients with a subchondral hypointensity on T1-weighted image (hyperintense on T2), indicating edema, were selected from a base population of 1,015 consecutive LBP patients to a follow-up MRI study within 18-72 months. Exclusion criteria were age >60 years, nerve root compression, a more specific back disease or a recent or major spine operation. The size and location of each subchondral signal abnormality and endplate lesion and the degree of degenerative disc changes were evaluated and compared between the baseline and follow-up studies. Most subchondral hypointensities were found at the L4/L5 or L5/S1 disc space, anteriorly and in both adjacent endplates. Almost all (53/54) hypointensities were associated with an endplate lesion. Twelve of the 54 subchondral hypointensities enlarged, six remained constant and 36 decreased or disappeared while five new ones appeared. Twenty-two (41%) hypointensities changed totally to hyperintensities or to mixed lesions. If the hypointensity increased, decreased or changed into hyperintensity, a change tended to develop in the adjacent endplate. If the hypointensity was absent or unchanged, endplate lesions did not tend to progress. In the absence of disc herniation or other specific spinal disease, subchondral hypointensities indicating edema are uncommon. They seem to have a highly variable course. There appears to be a link between endplate lesions and subchondral signal abnormalities. Further study is needed to explain the contribution of these findings to low back symptoms.

MR imaging features of foot involvement in patients with psoriasis

Objective To determine alterations of the soft tissues, tendons, cartilage, joint spaces, and bones of the foot using magnetic resonance (MR) imaging in patients with psoriasis. Materials and methods Clinical and MR examination of the foot was performed in 26 consecutive patients (52 ft) with psoriasis. As a control group, 10 healthy volunteers (20 ft) were also studied. Joint effusion/synovitis, retrocalcaneal bursitis, retroachilles bursitis, Achilles tendonitis, soft-tissue edema, para-articular enthesophytes, bone marrow edema, sinus tarsi syndrome, enthesopathy at the Achilles attachment and at the plantar fascia attachment, plantar fasciitis, tenosynovitis, subchondral cysts, and bone erosions, joint space narrowing, subchondral signal changes, osteolysis, luxation, and sub-luxation were examined. Results Clinical signs and symptoms (pain and swelling) due to foot involvement were present in none of the patients while frequency of involvement was 92% (24/26) by MR imaging. The most common MR imaging findings were Achilles tendonitis (acute and peritendinitis) (57%), retrocalcaneal bursitis (50%), joint effusion/synovitis (46%), soft-tissue edema (46%), and para-articular enthesophytes (38%). The most commonly involved anatomical region was the hindfoot (73%). Conclusion Our data showed that the incidence of foot involvement was very high in asymptomatic patients with psoriasis on MR imaging. Further MR studies are needed to confirm these data. We conclude that MR imaging may be of importance especially in early diagnosis and treatment of inflammatory changes in the foot.

MR imaging features of foot involvement in ankylosing spondylitis

Objective: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. Materials and Method: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. Results: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22%). Conclusion: In our experience, MR imaging may detect inflammatory and/or erosive bone, soft tissue, cartilage, tendon, and joint abnormalities in AS patients, even if AS patients did not have clinical signs and symptoms of foot involvement. If these data prove to be confirmed in further MR studies, MR imaging may be of importance especially in early diagnosis of inflammatory changes in the foot.

けい骨か外反骨切り術における術前・術後のＭＲＩ画像の比較

We evaluated subchondral low signal intense abnormality on T1-weighted MRI in the osteoarthritis (OA) and osteonecrosis (ON) of the knee after tibial Condyle valgus osteotomy (TCVO). Subjects consisted of 11 OA patients, aged 71 on average (range: 66-79) and 3 ON patients, aged 59 on average (range: 46-72). The MRI follow-up period was 18 months (range: 12-25) in the OA group and 17 months (range: 12-24) in the ON group. Clinical improvement was observed in all patients. Except for one patient in the OA group, T1-weighted MRI showed low signal intense area in the medial compartment of the knee. At follow-up, the MRI evaluation revealed a decrease in the low signal intense areas in 9 of the 10 OA patients and in 2 of the 3 ON patients. These results suggest that bone remodelling of the subchondral lesion can be expected after decompression and stabilizing surgery, TCVO.

変形性膝関節症の初期変化のＭＲＩ（脂肪抑制面像による検討） 第１報

Twenty-Three knees with early stages of osteoarthritis of the knee were assessed by fat suppressed magnetic resonance imaging (MRI). Abnormalities shown by fat suppressed MR included synovitis (39%), joint effusions (39%), degenerative changes of the meniscus (87%), soft tissue cysts (9%), hyaline cartilage thinning (70%) and subchondral signal changes (52%). Signal changes of the bone marrow were separated into three groups (localized type; 21%, diffuse type; 30%, mixed type; 4%). The results indicate that fat suppressed MR is capable of providing information about not only soft tissue, but also hyaline cartilage and bone marrow.

Osteoarthritis of the knee: correlation of subchondral MR signal abnormalities with histopathologic and radiographic features

Subchondral signal abnormalities are often present on magnetic resonance (MR) images of patients with osteoarthritis, but no study correlating these changes with histopathology has been published. We selected nine consecutive patients with clinical and radiographic diagnosis of moderate to severe osteoarthritis of the knee scheduled to undergo joint replacement surgery, and performed MR imaging and conventional radiographs preoperatively. After surgery, the resected portions of the femur and tibia underwent gross and microscopic examination, and the findings were correlated with the corresponding findings on the imaging studies. Subchondral MR signal abnormalities of the femur or tibia were present in seven of the nine patients, with intermediate signal on T1-weighted images and low or isointense signal on T2-weighted images. The subchondral signal abnormalities were hemispherical in configuration and corresponded predominantly to fibrous tissue replacing the fatty marrow. A component of trabecular thickening was also present.

Magnetic resonance imaging in osteoarthritis of the knee: correlation with radiographic and scintigraphic findings.

Twelve knees with a range of severity of knee osteoarthritis were assessed by magnetic resonance imaging (MRI) and technetium-99m labelled hydroxymethylene diphosphonate scintigraphy. Five magnetic resonance pulse sequences were evaluated. Proton density (TR = 1000, TE = 26 ms) and STIR (TR = 1500, TI = 100, TE = 30 ms) were chosen for further use. Abnormalities shown by MRI included joint effusions, meniscal disruption, hyaline cartilage thinning, subchondral signal changes, pseudocysts, and heterogeneity of signal from osteophytes. Certain MRI and scintigraphic appearances correlated: (a) 'hyperintense osteophytosis' and ipsilateral 'tramline' scintigraphic uptake, suggesting increased fat content in 'active' osteophytes; (b) subchondral signal change and 'extended' pattern, possibly reflecting inflammation, synovial leak, or fibrovascular repair; (c) patellofemoral joint signal changes and patellar isotope uptake.