Differences in Achilles tendon mechanical properties between professional ballet dancers and collegiate athletes utilizing shear wave elastography.

PURPOSE: To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. METHODS: An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. RESULTS AND DISCUSSION: Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. CONCLUSION: Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

Review of cooled radiofrequency ablation utilization for the treatment of symptomatic advanced knee arthritis and total knee arthroplasty.

Degenerative knee osteoarthritis is a progressive debilitating condition that affects millions of people worldwide. Most patients experience limited range of motion, inflammation, swelling, and pain. Management options can lead to short- and long-term pain relief. Short-term pain relief usually involves conservative medical treatments such as NSAIDs, weight loss, physical therapy, and corticosteroid injections. The ultimate long-term pain relief treatment method involves total knee arthroplasty. The treatment algorithm for knee OA also includes managing pain until a patient is eligible for arthroplasty. Furthermore, about 20% of patients experience chronic pain after TKA without complications such as hardware loosening and infection with limited treatment options. The pathophysiology of this is unknown. Cooled radiofrequency ablation has been demonstrated to be clinically effective by disrupting the integrity of deep sensory nerves and hence interfering with transmission of pain signal. The analgesic effect after c-RFA has been reported up to 24 months. Here, we present an overview of the clinical application of cooled radiofrequency ablation and a summary of its effectiveness in the treatment of pain in the setting of advanced OA and symptomatic TKA.

Cooled Radiofrequency Ablation for Chronic Joint Pain Secondary to Hip and Shoulder Osteoarthritis.

Osteoarthritis (OA) of the shoulder and hip is a leading cause of physical disability and mental distress. Traditional nonsurgical management alone is often unable to completely address the associated chronic joint pain. Moreover, a large number of patients are not eligible for joint replacement surgery owing to comorbidities or cost. Radiofrequency ablation (RFA) of articular sensory nerve fibers can disrupt the transmission of nociceptive signals by neurolysis, thereby providing long-term pain relief. A subtype of RFA, cooled RFA (CRFA), utilizes internally cooled electrodes to generate larger ablative zones compared with standard RFA techniques. Given the complex variable innervation of large joints such as the glenohumeral and hip joints, a larger ablative treatment zone, such as that provided by CRFA, is desired to capture a greater number of afferent nociceptive fibers. The suprascapular, axillary, and lateral pectoral nerve articular sensory branches are targeted during CRFA of the glenohumeral joint. The obturator and femoral nerve articular sensory branches are targeted during CRFA of the hip. CRFA is a promising tool in the interventionalist's arsenal for management of OA-related pain and symptoms, particularly in patients who cannot undergo, have long wait times until, or have persistent pain following joint replacement surgery. An invited commentary by Tomasian is available online. ©RSNA, 2022.

Knee Injuries in the Elite American Football Player: A Descriptive Pictorial Imaging and Mechanism of Injury Review.

ABSTRACT: Musculoskeletal injuries are common in American football, with an incidence ranging from approximately 10 to 35 per 1000 playing hours. Injuries occur more commonly in games than in practice. Although several studies have analyzed specific injury types in football, this review aims to describe the most common knee injuries sustained by American football players and to review the existing literature pertaining to the radiologic findings used in the diagnosis of these injuries.

Alternative treatment of hip pain from advanced hip osteoarthritis utilizing cooled radiofrequency ablation: single institution pilot study.

OBJECTIVE: To establish the effectiveness of cooled radiofrequency ablation in managing hip pain from osteoarthritis at 6 months after receiving treatment in patients who failed conservative treatments and are not surgical candidates due to comorbidities or unwillingness to undergo arthroplasty surgery by targeting the femoral and obturator branches and assessing the degree of hip pain relief and change of function. MATERIALS AND METHODS: This prospective pilot study includes a total of 11 consecutive patients experiencing persistent chronic hip pain in the setting of advanced osteoarthritis. Patients initially underwent anesthetic blocks of the obturator and femoral nerve branches to determine cooled radiofrequency ablation candidacy. After adequate response to the anesthetic blocks (> 50% immediate pain relief), patients were subjected to the procedures 2-3 weeks later. Treatment response was evaluated utilizing clinically validated questionnaires and visual analog score in order to assess impact on pain severity, stiffness, and functional activities of daily living. Follow-up outcome scores were collected up to 6 months after cooled radiofrequency ablation procedure. RESULTS: A total of 11 hips were treated consecutively between August 2019 and March 2020 (mean patient age 61.4 years; 8 M:3F). The mean total HOOS score improved significantly from baseline at 17.0 ± 6.0 to 52.9 ± 5.4 at a mean of 6.2 months after treatment (p < 0.0001), with significant improvement in mean pain score from 16.1 ± 6.6 to 53.4 ± 7.4 (p < 0.0001) and mean stiffness score from 15.0 ± 8.1 to 53.6 ± 11.0 (p < 0.0001). No major complications were encountered. No patients went on to re-treatment, surgery, or other intervention. CONCLUSION: Image-guided obturator and femoral nerve cooled radiofrequency ablation is effective and safe in treating chronic hip pain/stiffness in the setting of advanced osteoarthritis.

Management of uncomplicated total knee arthroplasty chronic pain and stiffness utilizing cooled radiofrequency ablation: a single institution pilot study.

OBJECTIVE: The objective of this study is to introduce cooled radiofrequency ablation technical feasibility as an alternative percutaneous image-guided treatment of chronic pain and stiffness in the setting of uncomplicated total knee arthroplasty. MATERIAL AND METHOD: This retrospective pilot study includes a total of 19 consecutive patients experiencing persistent chronic pain after total knee arthroplasty, without underlying hardware complications who had failed conservative care. Patients initially underwent anesthetic blocks of the genicular nerve branches to determine C-RFA candidacy. After adequate response to the anesthetic blocks (> 50% immediate pain relief), patients were subjected to cooled radiofrequency ablations 2-3 weeks later. Treatment response was evaluated utilizing clinically validated questionnaires (KOOS, the Knee Injury and Osteoarthritis Outcome Score) and visual analog scale (VAS) to assess pain severity, stiffness, functional activities of daily living, and use of pain medication. Follow-up outcome scores were collected up to 1 year after C-RFA procedure. RESULT: A total of 21 knees were treated consecutively between 4/2019 and 1/2020 (mean age 70.5 years; 5 M:14F). The mean total KOOS score improved significantly from baseline at 35.0 ± 14.0 to 64.2 ± 14.7 at a mean of 10.2 months after treatment (p < 0.0001), with significant improvement in mean stiffness score from 44.8 ± 16.7 to 68.8 ± 20 (p < 0.0001). The mean VAS score improved significantly from baseline at 8.30 ± 1.1 to 2.45 ± 1.8 (p < 0.0001). No major complications were encountered. No patients went on to receive re-treatment, surgical revision, or other intervention. CONCLUSION: Image-guided genicular nerve cooled radiofrequency ablation offers a promising alternative in treating chronic pain/stiffness in the setting of uncomplicated TKA.

Pilot study for treatment of symptomatic shoulder arthritis utilizing cooled radiofrequency ablation: a novel technique.

OBJECTIVE: To introduce cooled radiofrequency nerve ablation (C-RFA) as an alternative to managing symptomatically moderate to severe glenohumeral osteoarthritis (OA) in patients who have failed other conservative treatments and who are not surgical candidates or refuse surgery. MATERIAL AND METHODS: This prospective pilot study includes a total of 12 patients experiencing chronic shoulder pain from moderate to severe glenohumeral OA. Patients underwent anesthetic blocks of the axillary, lateral pectoral, and suprascapular nerves to determine candidacy for C-RFA treatment. Adequate response after anesthetic block was over 50% immediate pain relief. Once patients were deemed candidates, they underwent C-RFA of the three nerves 2-3 weeks later. Treatment response was evaluated using the clinically validated American Shoulder and Elbow Surgeons (ASES) score and visual analog scale (VAS) to assess pain, stiffness, and functional activities of daily living. Follow-up outcome scores were collected up to 6 months after C-RFA procedure. RESULTS: Twelve patients underwent C-RFA procedure for shoulder OA. VAS scores significantly improved from 8.8 ± 0.6 to 2.2 ± 0.4 6 months after the C-RFA treatment (p < 0.001). Patient's ASES score results significantly improved in total ASES from 17.2 ± 6.6 to 65.7 ± 5.9 (p < 0.0005). No major complications arose. No patients received re-treatment or underwent shoulder arthroplasty. CONCLUSION: Image-guided axillary, lateral pectoral, and suprascapular nerve C-RFA has minimal complications and is a promising alternative to treat chronic shoulder pain and stiffness from glenohumeral arthritis.

Multi-component T2∗ relaxation modelling in human Achilles tendon: Quantifying chemical shift information in ultra-short echo time imaging.

PURPOSE: To examine multi-component relaxation modelling for quantification of on- and off-resonance relaxation signals in multi-echo ultra-short echo time (UTE) data of human Achilles tendon (AT) and compare bias and dispersion errors of model parameters to that of the bi-component model. THEORY AND METHODS: Multi-component modelling is demonstrated for quantitative multi-echo UTE analysis of AT and supported using a novel method for determining number of MR-visible off-resonance components, UTE data from six healthy volunteers, and analysis of proton NMR measurements from ex vivo bovine AT. Cramer-Rao lower bound expressions are presented for multi- and bi-component models and parameter estimate variances are compared. Bias error in bi-component estimates is characterized numerically. RESULTS: Two off-resonance components were consistently detected in all six volunteers and in bovine AT data. Multi-component model exhibited superior quality of fit, with a marginal increase in estimate variance, when compared to the bi-component model. Bi-component estimates exhibited notable bias particularly in R2,1∗ in the presence of off-resonance components. CONCLUSION: Multi-component modelling more reliably quantifies tendon matrix water components while also providing quantitation of additional non-water matrix constituents. Further work is needed to interpret the origin of the observed off-resonance signals with preliminary assignments made to chemical groups in lipids and proteoglycans.

Review of Extraosseous Applications of Thermal Ablation in the Treatment of Moderate to Severe Large Joint Osteoarthritis.

Osteoarthritis (OA) is the most common joint disease worldwide, leading to significant pain, restricted range of motion, and disability. A gap exists between short- and long-term symptom-relieving therapies. Although arthroplasty is an effective treatment for symptomatic end-stage disease, most patients ultimately do not receive a joint replacement due to suboptimal surgical qualifications, comorbidities, or an aversion to surgery. The lack of additional treatment options in this setting makes opioid agonists a commonly used pharmacologic agent, contributing to the addiction epidemic that greatly afflicts our communities. Cooled radiofrequency ablation (CRFA) has arisen as a treatment modality in the setting of moderate to severe OA among patients refractory to conservative management, generally showing greater efficacy compared with other existing strategies. This review focuses on the benefits of CRFA and its technical feasibility as a management option among patients experiencing debilitating large joint OA with limited clinical options.

Osteoarthritis of the hip: are degenerative tears of the acetabular labrum predictable from features on hip radiographs?

BACKGROUND: A common feature of hip arthritis is the presence of labra tears. Recent literature suggests against the use of magnetic resonance imaging (MRI) in patients aged >45 years for the assessment of hip pain related to arthritis. PURPOSE: To determine if radiographic features of osteoarthritis detectable on routine hip radiographs are accurate and reliable surrogate markers of degenerative acetabular labral tears identified on MR arthrography (MRA) and corroborated during arthroscopy. MATERIAL AND METHODS: A retrospective study involving 86 symptomatic patients (hip pain) with radiologic work-up included MRA and pelvic or hip radiographs that underwent hip arthroscopy within three months. Imaging characteristics assessed on hip radiographs include measurements of superior acetabular, femoral head osteophyte, cortical thickness of the femoral shaft, and minimum joint space as well as presence of subchondral sclerosis of the femoral head and acetabulum, femoral shaft buttressing, and grade of arthritis. Presence of a labral tear was determined by consensus between three readers as well as by surgical correlation. The Pearson's chi-squared and Fisher's exact tests were used to compare presence of labral tears with each radiographic feature. RESULTS: Seventy-one patients (82.6%) had labral tears: 49 (69%) women and 22 (31%) men. Receiver operating characteristic analysis showed statistical significance (P<0.05) between presence of a labral tear and acetabular and femoral head osteophyte sizes but failed to demonstrate any significance regarding acetabular subchondral sclerosis, cortical thickness, buttressing, or minimum joint space. CONCLUSIONS: Radiographic markers such as the acetabular and femoral head osteophyte sizes demonstrated statistical significance with the presence of labral tears.

Subchondral insufficiency fracture of the knee: unicompartmental correlation to meniscal pathology and degree of chondrosis by MRI.

OBJECTIVE: To assess the relationship between low- and high-grade subchondral insufficiency fracture of the knee (SIFK) and meniscal tear/type/location, severity of meniscal extrusion, grade of chondrosis, and extent of surrounding edema-like marrow signal intensity. MATERIALS AND METHODS: Our retrospective study included 219 patients with knee pain and SIFK seen on MRI. SIFK lesions were categorized from grade 1 to 4 with a low grade (1 and 2) vs high grade (3 and 4) distinction. Associations between SIFK grade, location, lesion dimensions, edema-like marrow signal intensity, incidence of meniscal tears/type/location, and chondrosis (grade 0 to grade 4), as well as patients' age and weight, were assessed. RESULTS: Our analysis consisted of 115 males and 104 females with 17% of the patients showing grade 1 SIFK, 59% grade 2, 16% grade 3, and 8% grade 4. No chondrosis or low-grade chondrosis was mostly present in patients with low-grade SIFK (68.9%), whereas high-grade chondrosis was mostly present in patients with high-grade SIFK lesions (65.4%) (p < 0.01). Further sub-analysis demonstrated that high-grade SIFK was associated with high-grade chondrosis in the same compartment (p < 0.01) but not in the adjacent compartment. There was a significant difference in the extent of edema-like marrow signal intensity between the two groups, with high-grade SIFK more frequently demonstrating severe edema-like marrow signal intensity compared to low-grade SIFK (p < 0.01). CONCLUSION: High-grade SIFK lesions are associated with unicompartmental high-grade chondrosis.

Shear wave elastography assessment and comparison study of the Achilles tendons in optimally conditioned asymptomatic young collegiate athletes.

OBJECTIVE: To assess the functional parameters of the Achilles tendons among asymptomatic college level athletes using shear wave elastography (SWE) and to describe the relationship to athlete demographics and anthropometric lower extremity measurements. MATERIAL AND METHODS: Sixty-five athletes were included in this IRB-approved study. SWE measurements were made on two tendon positions (neutral state and active maximum dorsiflexion) with two different probe orientations (longitudinal and transverse). Associations were assessed with BMI, tibial/foot length, type of sports, and resting/maximal dorsiflexion-plantar flexion angles. RESULTS: Thirty-five (53.8%) males and 30 (46.2%) females with an overall mean age of 20.9 years (± 2.8), mean height of 176 cm (± 0.11), and mean weight of 74.1 kg (± 12) were studied. In the neutral state, the mean wave velocity of 7.5 m sec-1 and the mean elastic modulus of 176.8 kPa were recorded. In active maximum dorsiflexion, the mean velocity was 8.3 m sec-1 and mean elastic modulus was 199 kPa. On the transverse view, the mean velocity and elastic measurements were significantly lower (p = 0.0001). No significant differences in SWE parameters were seen between male and female athletes regardless of probe orientation (p < 0.05) with SWE values being higher in the running group vs non-running group (p < 0.05). In neutral state, longitudinal SWE measurements correlated with the tibia-foot length whereas transverse measurements correlated with the tendon diameter and ankle resting angle (ARA) (p < 0.005). CONCLUSION: SWE can distinguish functional differences in Achilles tendon stiffness between athletes engaged in running-intensive sports compared with other athletes.

Clinicoradiographic predictors of percutaneous bone biopsy results among patients with suspected thoracolumbar spine infection.

BACKGROUND: Image-guided percutaneous thoracolumbar spine biopsy is frequently performed in the setting of suspected septic facet arthritis or discitis osteomyelitis (DOM). There are limited data regarding factors associated with a positive biopsy result among these patients. MATERIALS AND METHODS: Patients with suspected DOM who underwent spine biopsy were identified. Samples yielding a positive culture and/or histopathology suggestive of acute osteomyelitis were considered positive. The associations between selected medical comorbidities, laboratory values, pre-biopsy antibiotic administration, imaging findings and biopsy results were investigated. RESULTS: 121 patients underwent percutaneous biopsy with 35.5% yielding positive results. Biopsy results showed no correlation with comorbidities. The only laboratory value that correlated with a positive biopsy yield was blood culture positivity (p = 0.03). The imaging findings that correlated with a positive biopsy yield were the presence of a paraspinal fluid collection or epidural abscess (p = 0.003 and 0.018, respectively). Sampling paraspinal fluid collections, when present, resulted in a higher rate of a positive biopsy yield compared to sampling of bone or disc (p = 0.006). Patients who received antibiotics had a higher rate of a positive biopsy yield (p = 0.014). In those with positive blood cultures, biopsy yielded the same antimicrobial susceptibility profile in 13/14 cases. CONCLUSION: The presence of a paraspinal fluid collection or epidural abscess is correlated with positive biopsy yield, and paraspinal fluid collections should be targeted for biopsy. Other imaging findings did not correlate with biopsy yield. Biopsy may not offer additional information for patients with positive blood cultures.

Safety and efficacy comparison of three- vs four-needle technique in the management of moderate to severe osteoarthritis of the knee using cooled radiofrequency ablation.

PURPOSE: To analyze the safety and efficacy of image-guided genicular nerve cooled radiofrequency ablation (C-RFA) for the treatment of pain in non-surgical candidates with moderate to severe knee osteoarthritis (OA) and to compare three- vs four-needle technique. METHOD: This retrospective study included 50 consecutive patients with pain from moderate to severe knee OA refractory to anti-inflammatory analgesia that failed multiple intra-articular lidocaine-steroid injections and who were non-surgical total knee arthroplasty candidates because of comorbidities. Patients initially underwent anesthetic blocks of the superior medial/lateral femoral and inferior medial tibial genicular nerve branches and in some cases the suprapatellar genicular nerve branch. Radiofrequency ablations of the same nerve branches were performed 1-2 weeks after the nerve blocks. Follow-up outcome was collected at approximately 2 weeks, 1, 3, and 6 months after the C-RFA procedure utilizing VAS and clinically validated questionnaires. RESULTS: A total of 77 knees were treated. The mean total KOOS score improved significantly from baseline at 24.7 ± 14.1 to 59.4 ± 26.5 at 6 months after treatment (p < 0.0001), with significant improvement in mean pain score from 25.5 ± 15.2 to 64.5 ± 25.2 (p < 0.0001) and mean stiffness score from 35.1 ± 21.9 to 65.8 ± 24.9 (p < 0.0001). At 6 months, 65% of all patients demonstrated decreased opiate medication usage, 79% of patients in the four-needle, and 45% of patients in the three-needle arms (p = 0.03). No complications were reported. CONCLUSIONS: The four-needle treatment approach offers an advantage in the overall efficacy in treating stiffness and pain in patients with moderate-to-severe OA refractory to conservative treatments leading to decreased opiate usage without complications.

Do Not Judge an Ossicle by Its Size: Type 1 Ossicles Associated With Posterior Tibial Tendon Dysfunction.

INTRODUCTION: Patients with type II navicular ossicles have traditionally been considered to be symptomatic, whereas patients with type I and III bones are considered asymptomatic without additional relevant imaging findings. The main objective of this study is to investigate the association of type I os naviculare with clinical symptomology and magnetic resonance imaging findings in comparison to types II and III ossicles. METHODS: Three hundred nine subjects with accessory navicular bone types were identified, and their associations with focal navicular pain, pes planus alignment, ossicle or proximal navicular bone marrow edema pattern presence (BMEP), and posterior tibial tendon (PTT) sheath fluid distension were assessed. Fisher's exact test was used for categorical data and unpaired t tests for continuous data. Intraobserver and interobserver agreement was calculated. RESULTS: Overall, 28% (85/309) of type I, 57% (176/309) of type II, and 16% (48/309) of type III accessory bones had focal navicular pain (type I vs type II, P = 0.17; type III vs type II, P = 0.001). Thirty-two percent of type I, 38% type II, and 8% type III accessory bones had pes planus (type I vs II, P = 0.3; type III vs type II, P = 0.001). Nine percent of type I, 48% of type II, and 6% of type III accessory bones had BMEP (type I vs II, P < 0.0001; type III vs type II, P = 0.001). Thirty-three percent of type I, 42% of type II, and 6% of type III accessory bones had PTT intrasheath fluid (type I vs II, P = 0.16; type III vs type II, P = 0.001). CONCLUSIONS: Symptomatic type I navicular ossicle patients demonstrate an increased tendency to present with early findings of PTT dysfunction and morphologic pes planus to a greater degree than previously recognized. LEVEL OF CLINICAL EVIDENCE: 3.

In vivo Sonographic Characterization of The Achilles Tendons in Healthy Young Collegiate Athletes as a Function of Ankle Position.

This study aims to describe the normative Achilles tendon properties in a collegiate subject cohort. Achilles tendon evaluations in 65 asymptomatic college-level athletes by ultrasound B mode on two tendon positions (neutral state and active maximum dorsiflexion). Correlation was made to BMI, tibial/foot length, maximal calf circumference, type of sports, resting/maximal dorsiflexion-plantar flexion angles among other factors. The mean Achilles tendon length was found to be 14.9 cm, mean transverse dimension of 1.38 cm, thickness of 0.49 cm and cross-sectional area of 0.61 cm2 in the relaxed state. Males had greater tendon length than the female athletes (15.5 (M) vs 14.3cm (F) in the relaxed position and 16.1 (M) vs 15.2cm (F) in the stretched position), tendon width (1.4 vs 1.3 cm), tendon thickness (0.51 vs 0.46 cm), tendon cross-sectional area (0.65 vs 0.57 cm2) and foot length (27.6 cm vs 26.6 cm). The Achilles tendon parameters such as length in the relaxed state had a statistically significant correlation with the height, weight, and foot length, while the tendon length in the dorsiflexed-stretched position had a statistically significant relationship to foot length, tibia length, calf circumference and range of motion (both in maximum dorsiflexion and plantar flexion positions; p < .05 for all comparison). Differences in the correlation between the Achilles tendon parameters and body habitus was recorded as a function of ankle position. Tendon dimensions and cross-sectional areas were larger in male vs female athletes. Calf circumferences and Achilles tendon resting angle were outlined. No significant difference was found in the Achilles tendon dimensions regardless of the leg dominance with similar range of motion regardless of athlete gender.

Nomenclature of Subchondral Nonneoplastic Bone Lesions.

OBJECTIVE. The purpose of this article is to summarize the nomenclature of nonneoplastic conditions affecting subchondral bone through a review of the medical literature and expert opinion of the Society of Skeletal Radiology Subchondral Bone Nomenclature Committee. CONCLUSION. This consensus statement summarizes current understanding of the pathophysiologic characteristics and imaging findings of subchondral nonneoplastic bone lesions and proposes nomenclature to improve effective communication across clinical specialties and help avoid diagnostic errors that could affect patient care.

Subchondral insufficiency fracture of the knee: grading, risk factors, and outcome.

OBJECTIVE: To propose an magnetic resonance imaging (MRI) grading system for subchondral insufficiency fracture of the knee (SIFK) to predict outcome and assess risk factors. MATERIALS AND METHODS: A total of 50 SIFK patients were retrospectively reviewed utilizing two MRI examinations approximately a year apart and compared them with 51 control subjects. A grading system was introduced that classifies lesions as low- vs high-grade. Lesion location 3D dimensions, extent of bone marrow edema (BME), location of meniscal tears and associated extrusion, degree of chondrosis and among other parameters were stratified according to lesion grade and compared with follow-up examinations. Statistical analyses were performed (Pearson's correlation, binary logistic regression, and Chi-squared analysis). RESULTS: The majority of SIFK lesions were low-grade (LG; 78%) and most of them (70%) were observed in the medial femoral condyle. Predictor variables comparing low-grade and high-grade SIFK lesions included meniscal tear (p = 0.01), degree of extrusion (p < 0.003), chondrosis (p = 0.01), medial chondrosis grade (p = 0.001), medial femoral condyle (p = 0.01), surface collapse (p < 0.0001), marrow edema improvement (p < 0.0001), first MRI anteroposterior dimension (p = 0.001), transverse dimension (p < 0.001), and ellipsoid volume (p = 0.02). Predictor variables found to be significantly different between controls and patients were meniscal tear (p = 0.024), location of the medial meniscal tear (p < 0.0001), degree of extrusion (p < 0.0001), chondrosis (p < 0.0001), joint effusion (p < 0.0001), Baker's cyst (p < 0.0001), knee lock (p = 0.03) and buckle (p = 0.01), and history of trauma (p = 0.01). CONCLUSION: A SIFK grading system for MRI is introduced. Surrogate markers of high-grade lesions include medial meniscus posterior root tears with associated moderate to severe extrusion, high-grade chondrosis, larger lesion sizes (anteroposterior/transverse), and articular surface collapse. Improvement of BME on follow-up was highly predictive of low-grade disease.

Tenosynovial fluid as an indication of early posterior tibial tendon dysfunction in patients with normal tendon appearance.

OBJECTIVE: Our primary aim was to quantify the posterior tibial tendon (PTT) sheath fluid volume in individuals with the clinical diagnosis of stage 1 posterior tibial tendon dysfunction (PTTD) and no MRI-detectable intra-substance tendon pathology and compare them with patients with other causes of medial ankle pain, also without MRI-detectable intra-substance PTT pathology and with normal controls. We also wanted to determine if there is a fluid measurement that correlates with the clinical diagnosis of PTTD. MATERIALS AND METHODS: A total of 326 individuals with medial ankle pain and no intra-substance PTT pathology were studied. Group 1 included 48 patients with a clinical diagnosis of stage 1 PTT dysfunction, group 2 comprised 278 patients with other causes of medial ankle pain, and a third control group consisted of 56 patients without any medial ankle pain. MRI-based geometric measurements included PTT fluid volume, maximum cross-sectional fluid area, and fluid width. Fluid measurements were compared between groups and measurement reliability was tested. RESULTS: Group 1 showed greater PTT fluid volume, area, and width compared with groups 2 (other causes of medial ankle pain) and 3 (asymptomatic controls) (all p values < 0.001). A 9-mm threshold maximum fluid width was associated with PTTD (sensitivity 84%, specificity 85%). Measurements were reliable (all p values < 0.03) among three observers blinded to the gold standard. CONCLUSION: Patients with stage 1 PTT dysfunction displayed greater volumes of tendon-sheath fluid than those with other causes of medial ankle pain and compared with asymptomatic controls. A threshold maximum fluid width greater than or equal to 9 mm distinguishes those with PTTD. An association between tendon sheath fluid distension and the clinical diagnosis of stage 1 posterior tibial tendon disease in the setting of no MRI-detectable intra-substance tendon pathology may allow for differentiation of medial ankle pain from other sources and may allow for early intervention aimed at preventing progressive PTTD. The level of evidence was prognostic (level III).