Bone marrow edema at ligament insertion is an accurate MRI sign of deltoid ligament injury.

BACKGROUND: Magnetic resonance imaging (MRI) is effective in diagnosing deltoid ligament (DL) injury but its sensitivity in chronic cases is low. Additional diagnostic signs are required to reduce the risk of a false negative diagnosis. PURPOSE: To evaluate the added diagnostic value of bone marrow edema at the ligament insertion (BMELI) of DL to the MRI assessment of chronic DL injury. MATERIAL AND METHODS: One hundred patients who consecutively came to our institution between November 2018 and December 2021 and underwent arthroscopic surgery for chronic ankle instability (CAI) were enrolled in the present study. Preoperative MR images were retrospectively reviewed by two orthopedic surgeons to evaluate the sensitivity, specificity and interobserver reliability of three MRI signs in diagnosing chronic DL injury, namely, abnormal ligamentous morphological characteristics (ALMC), BMELI and medial clear space (MCS). RESULTS: Taking arthroscopy as the reference standard, there were 34 patients with and 66 without DL injury. ALMC had 64.71% (22/34; 46.47-79.70) sensitivity and 83.33% (55/66; 71.71-91.00) specificity, BMELI had 70.59% (24/34; 52.33-84.29) sensitivity and 95.45% (63/66; 86.44-98.82) specificity and MCS had 26.47% (9/34; 13.51-44.65) sensitivity and 92.42% (61/66; 82.50-97.18) specificity. Compared with ALMC, BMELI had similar efficacy in superficial cases (P = 0.06) and greater efficacy in deep cases (P = 0.04). All three signs showed good interobserver agreement (kappa values all above 0.7). CONCLUSION: BMELI can reliably indicate concomitant injury to the DL in CAI patients. Using BMELI as a sign of chronic DL injury when ALMC is unclear may reduce the risk of a false negative diagnosis.

Can coracoacromial ligament degeneration be evaluated with preoperative MRI?

BACKGROUND: Subacromial impingement syndrome is one of the most common causes of painful shoulder in the middle-aged and elderly population. Coracoacromial ligament (CAL) degeneration is a well-known indicator for subacromial impingement. PURPOSE: To examine the relationship between CAL thickness on preoperative magnetic resonance imaging (MRI), arthroscopic CAL degeneration and types of rotator cuff tears. MATERIAL AND METHODS: Video records of patients who underwent arthroscopic shoulder surgery between 2015 and 2021 were retrospectively scanned through the hospital information record system. In total, 560 patients were included in this study. Video records of the surgery were used to evaluate the grade of coracoacromial ligament degeneration and the type of cuff tear. Preoperative MRI was used to measure CAL thickness, acromiohumeral distance, critical shoulder angle, acromial index, and acromion angulation. RESULTS: Significant differences were observed between grades of CAL degeneration in terms of CAL thickness (P < 0.001). As CAL degeneration increases, the mean of CAL thickness decreases. According to the results of post-hoc analysis, the mean CAL thickness of normal patients was significantly higher than those of patients with full-thickness tears (P = 0.024) and massive tears (P <0.001). Patients with articular-side, bursal-side, and full-thickness tears had significantly higher CAL thickness averages than patients with massive tears. CONCLUSION: This study showed that the CAL thickness decreases on MRI as arthroscopic CAL degeneration increases. High-grade CAL degeneration and therefore subacromial impingement syndrome can be predicted by looking at the CAL thickness in MRI, which is a non-invasive method.

Editorial Commentary: When Properly Indicated, Combined Tibial Tubercle Osteotomy Reduces Risk of Recurrent Patellofemoral Instability More Than Does Isolated Medial Patellofemoral Ligament Reconstruction.

Clinical recognition and surgical treatment of patellofemoral instability has evolved dramatically over the past 3 decades. However, few patellofemoral patients present with an isolated medial patellofemoral ligament (MPFL) tear. Rather, patients often demonstrate patella alta, increased tibial tubercle to trochlear groove (TT-TG) distance, dysplasia, coronal malalignment, or combinations thereof. Given this, concomitant procedures such as tibial tubercle osteotomy (TTO) have become increasingly popularized, given their ability to anteriorize, medialize, and even distalize the patella to correct tracking. It is generally recommended that concurrent TTO be considered with primary medial patellofemoral ligament reconstruction (MPFLR) in patients with closed physes whose TT-TG distance is larger than 17 to 20 mm. MPFLR + TTO is generally safe and may decrease risk of revision surgery when compared with isolated MPFLR in properly indicated patients. However, it important to measure both knee rotation angle and tibial tubercle lateralization on magnetic resonance imaging, as both factors influence TT-TG. In patients in whom abnormal knee rotation angle is felt to be the primary driver of TT-TG, surgeons should proceed with caution when considering concomitant TTO. The pen may be mightier than the sword, but the osteotome may be mightier yet than the scalpel.

Concomitant anterior medializing osteotomy and MPFL reconstruction improves patellar tilt when compared to MPFL reconstruction alone.

PURPOSE: Understanding how surgical procedures influence anatomic factors associated with patellofemoral instability can help guide surgeons when planning treatments for individual patients. This study sought to understand how patellar tilt is affected in adolescent patients with elevated pre-operative tibial tuberosity to trochlear groove (TT-TG) values undergoing medial patellofemoral ligament reconstruction (MPFLR) with or without an anterior medializing osteotomy (AMZ). METHODS: Utilizing a prospective database of 274 patellofemoral instability patients who underwent MPFLR ± AMZ by one of two orthopedic surgeons at a single institution, those who underwent MPFLR + AMZ were identified. Pre-operative and post-operative magnetic resonance imaging (MRI) were used to measure TT-TG distance, while radiographs were used to measure patellar tilt (tilt). Patients were matched based on age at surgery (within 2 years) and pre-operative TT-TG distance (within 2 mm) to a comparison cohort of patients who underwent isolated MPFLR (iMPFLR) without osseous procedures. RESULTS: A total of 56 patients were analyzed (28 per group). The mean age of the cohort was 15.5 ± 2.0 years and was similar between both groups (15.9 ± 1.9 versus 15.1 ± 2.0 years [n.s]). When comparing the two cohorts, significant pre- to post-operative decreases in patellar tilt for both MPFLR + AMZ (6.6 degrees, p < 0.001) and iMPFLR (3.9 degrees, p = 0.013) were noted. While there were no differences in pre-operative patellar tilt (21.2 ± 3.5 versus 21.1 ± 3.4 [n.s]), post-operatively, MPFLR + AMZ had significantly less patellar tilt than iMPFLR (13.2 ± 5.5 versus 16.5 ± 4.4, p = 0.017). CONCLUSIONS: This study found that patellar tilt significantly improved in participants undergoing either MPFLR + AMZ or iMPFLR. In addition, those undergoing MPFLR + AMZ were found to have significantly lower post-operative tilt than those undergoing iMPFLR. If patellar tilt is found pre-operatively to be significantly elevated and a risk for future dislocations, these findings suggest that surgeons might strongly consider MPFLR with AMZ to further address the increased tilt. LEVEL OF EVIDENCE: III.

Intrameniscal degeneration and meniscotibial ligament loosening are associated factors with meniscal extrusion of symptomatic discoid lateral meniscus.

PURPOSE: This study aimed to compare the amount of extrusion of the discoid lateral meniscus (DLM), which was symptomatic and required surgery, with normal meniscuses and asymptomatic DLMs and examine factors associated with the extrusion of symptomatic DLM. METHODS: Medical records of participants with DLM or normal lateral meniscus (LM) were retrospectively reviewed using magnetic resonance imaging (MRI). DLM cases were divided into symptomatic and asymptomatic groups. The midbody meniscal extrusion was measured using mid-coronal MRI. The association between meniscal extrusion and MRI findings, including the meniscofemoral ligament, meniscotibial ligament (MTL), intrameniscal signal intensity of the peripheral rim, meniscal shift, and skeletal maturity, was evaluated. RESULTS: Eighty-six knees with DLM (63 symptomatic) were included. The control group included 31 patients. The symptomatic group showed significantly greater meniscal extrusion (mean ± standard deviation symptomatic DLM: 1.0 ± 1.1 mm, asymptomatic DLM: 0.1 ± 0.4 mm, and normal LM: 0.3 ± 0.6 mm, P < 0.001) and had a significantly higher incidence of MTL loosening (P = 0.02) and intrameniscal signal (P < 0.001) than the other two groups. In the symptomatic group, multivariable linear regression analysis showed that MTL loosening [ß = 1.45, 95% confidence interval (CI) 1.03-1.86, P < 0.001] and intrameniscal signal (ß = 0.49, 95% CI 0.09-0.90, P = 0.002) were independent associated factors. CONCLUSIONS: LM extrusion was significantly more common in patients with symptomatic DLM than in those with asymptomatic DLM or a normal LM. MTL loosening and intrameniscal high-signal intensity on MRI were independently associated with meniscal extrusion. These findings help explain the pathogenesis and diagnosis of symptomatic DLM. LEVEL OF EVIDENCE: III.

Diagnosis of joint invasion in patients with malignant bone tumors: value and reproducibility of direct and indirect signs on MR imaging.

OBJECTIVES: To evaluate the performance and reproducibility of MR imaging features in the diagnosis of joint invasion (JI) by malignant bone tumors. METHODS: MR images of patients with and without JI (n = 24 each), who underwent surgical resection at our institution, were read by three radiologists. Direct (intrasynovial tumor tissue (ITT), intraarticular destruction of cartilage/bone, invasion of capsular/ligamentous insertions) and indirect (tumor size, signal alterations of epiphyseal/transarticular bone (bone marrow replacement/edema-like), synovial contrast enhancement, joint effusion) signs of JI were assessed. Odds ratios, sensitivity, specificity, PPV, NPV, and reproducibilities (Cohen's and Fleiss' κ) were calculated for each feature. Moreover, the diagnostic performance of combinations of direct features was assessed. RESULTS: Forty-eight patients (28.7 ± 21.4 years, 26 men) were evaluated. All readers reliably assessed the presence of JI (sensitivity = 92-100 %; specificity = 88-100%, respectively). Best predictors for JI were direct visualization of ITT (OR = 186-229, p < 0.001) and destruction of intraarticular bone (69-324, p < 0.001). Direct visualization of ITT was also highly reliable in assessing JI (sensitivity, specificity, PPV, NPV = 92-100 %), with excellent reproducibility (κ = 0.83). Epiphyseal bone marrow replacement and synovial contrast enhancement were the most sensitive indirect signs, but lacked specificity (29-54%). By combining direct signs with high specificity, sensitivity was increased (96 %) and specificity (100 %) was maintained. CONCLUSION: JI by malignant bone tumors can reliably be assessed on preoperative MR images with high sensitivity, specificity, and reproducibility. Particularly direct visualization of ITT, destruction of intraarticular bone, and a combination of highly specific direct signs were valuable, while indirect signs were less predictive and specific. KEY POINTS: • Direct visualization of intrasynovial tumor was the single most sensitive and specific (92-100%) MR imaging sign of joint invasion. • Indirect signs of joint invasion, such as joint effusion or synovial enhancement, were less sensitive and specific compared to direct signs. • A combination of the most specific direct signs of joint invasion showed best results with perfect specificity and PPV (both 100%) and excellent sensitivity and NPV (both 96 %).

Derotational distal femoral osteotomy yields satisfactory clinical outcomes in pathological femoral rotation with failed medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of de-rotational distal femoral osteotomy (DDFO) in patients who underwent primary medial patellofemoral ligament reconstruction (MPFLR) failure with increased femoral anteversion along with high-grade J sign. METHODS: Between 2011 and 2019, 14 patients underwent DDFO revision surgery due to failed MPFLR. The pre- and postoperative J sign grade, Caton-Deschamps index (CDI), tibial tuberosity-trochlear groove (TT-TG) distance, femoral anteversion angle (FAA), patellar lateral tilt angle (PLTA), MPFL graft laxity, and patient-reported outcomes (Kujala, Lysholm, Tegner, and International Knee Documentation Committee (IKDC) subjective scores) were collected. The anterior-posterior and proximal-distal distances between the actual point and the Schöttle point were also calculated. RESULTS: Fourteen patients underwent MPFLR revision by DDFO combined with MPFLR. The mean PLTA improved from 40.7° ± 11.9° to 20.5° ± 8.7° (P < 0.001). The mean FAA significantly decreased from 42.7° ± 12.0° to 14.1° ± 5.2° (P < 0.001). The mean patellar laxity index (PLI) decreased from 82.4% preoperatively to 15.1% postoperatively (P < 0.001). None of these patients experienced subluxation or re-dislocation during follow-up of 29.7 ± 5.0 months after revision surgery. Meanwhile, the Tegner score at the last follow-up ranged from 3 to 6, with a median of 5. The Kujala, Lysholm, and IKDC subjective scores showed significant improvements, from a mean of 51.0 ± 6.8 preoperatively to 75.4 ± 5.1 postoperatively (P < 0.001), 49.2 ± 7.9 to 75.2 ± 7.2 (P < 0.001), and 42.9 ± 6.2 to 76.8 ± 6.0 (P < 0.001), respectively. The proportion of patients with a high-grade J sign was significantly lower postoperatively than preoperatively (100% vs. 14%). Four out of 14 patients (29%) showed femoral tunnel mal-positioning. CONCLUSION: MPFLR revision by DDFO combined with MPFLR achieved favorable clinical outcomes in patients with increased femoral anteversion along with high-grade J sign. LEVEL OF EVIDENCE: IV.

Attachment Type, Thickness, and Volume of the Posterior Meniscofemoral Ligament and Meniscal Pathology.

Several studies have investigated the relationship between the thickness of the posterior meniscofemoral ligament (pMFL) and the presence of a discoid meniscus. We investigated the correlation between meniscal pathology and anatomic features of pMFL such as attachment type, thickness, and volume. We retrospectively evaluated 191 patients who underwent knee MRI. MR images were reviewed to assess the attachment type of the pMFL on the medial femoral condyle (high vs. low), the thickness of the pMFL, and the presence of a meniscal tear or a discoid meniscus. The pMFL volume was quantified by using three-dimensional (3D) segmentation software. The relationship between the frequency of medial or lateral meniscal tear and anatomic features of pMFL were analyzed using Chi-square, Fisher's exact, or Mann-Whitney U test. High type pMFLs had significantly greater thickness and volume than low type pMFLs (p < 0.001). Patients with degenerative lateral meniscal tear had significantly higher thickness and volume of the pMFL than patients with intact lateral meniscus (p < 0.05). The pMFL thickness and volume were not significantly related to traumatic lateral meniscal tear, medial meniscal tear, and discoid meniscus. High type pMFLs tended to be thicker and larger than low type pMFLs and higher thickness and volume of the pMFL was significantly related to the degenerative lateral meniscal tear. However, the attachment type of the pMFL itself was not significantly related to the lateral meniscal tear as well as the medial meniscal tear.

An Unrecognized Ligament and its Ossification in the Craniocervical Junction: Prevalence, Patient Characteristics, and Anatomic Evidence.

BACKGROUND: In the craniocervical junction, the ligaments between the anterior foramen magnum and the anterior arch of the atlas are not well defined, and ossification of the ligaments in this region has rarely been reported. Characterizing the anatomy and ossification of these ligaments may help in the diagnosis and treatment of disorders in this region. QUESTIONS/PURPOSES: (1) What is the prevalence of an unrecognized ossification at the craniocervical junction in patients with cervical spine disorders, and what are the patient characteristics associated with this ossification? (2) Do patients with this ossification have a greater risk of ossification of other structures at the craniocervical junction or cervical spine? (3) Is there an unreported ligament at this ossified site? METHODS: We conducted a retrospective study of 578 hospitalized patients who underwent CT for cervical spine disorders between January 2016 and July 2020. Based on the inclusion criteria, 11% (66 of 578) were excluded because of a cervical or craniocervical tumor, deformity, infection, fracture or dislocation, or prior surgery, leaving 89% (512 of 578) for analysis. These 512 patients had diagnoses of cervical radiculopathy, cervical myelopathy, cervical spondylotic amyotrophy, cervical spinal cord injury without a radiographic abnormality, or axial neck pain. Their mean age was 57 years (range 22-90 years), and 60% of the patients were men. Patient characteristics including age, gender, and diagnosis were retrieved from a longitudinally maintained institutional database. CT images were used to assess the presence of a previously unrecognized ossification and ossification of other structures in the craniocervical junction and cervical spine, including the posterior longitudinal ligament, anterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, and apical ligament, as well as diffuse idiopathic skeletal hyperostosis (DISH). The association between these structures was also assessed. This unreported ossification was called the capped dens sign. It was defined and graded from 1 to 3. Grade 3 was defined as the typical capped dens sign. Cervical spine MRI was used to assess whether there was an unreported structure in the same region as where the capped dens sign was detected on CT images. In the database of a recent study, there were 33 patients younger than 41 years. Nine percent (three of 33) were excluded because they did not have cervical spine MRI. MRIs of the remaining 30 patients were assessed. Their mean age was 35 years (range 22-40 years), and 58% were men. All cervical spine CT images and MRIs were reviewed by one senior spine surgeon and one junior spine surgeon twice with a 2-week interval. Blinding was accomplished by removing identifying information from the radiographs and randomly assigning them to each examiner. Any discrepancy with respect to the grade of the capped dens sign was adjudicated by a third blinded senior spine surgeon. Intrarater and interrater reliabilities were assessed by calculating weighted kappa statistics. No ligament or membrane was reported at this site. MRI is not sensitive to identify thin tissue in this region, especially when severe degeneration has occurred. A cadaveric study was conducted to discover a potential ligament between the inferior margin of the foramen magnum and the anterior arch of the atlas, as prompted by the newly discovered ossification in the clinical analysis of this study. Six embalmed human cadaveric craniocervical regions (three male and three female cadavers; median age 56 years, range 45-78 years) were dissected by a senior anatomist and a senior anatomy technician. A mid-sagittal section of the craniocervical junction was created, allowing us to explore the interval between the anterior foramen magnum and anterior arch of the atlas. A histologic analysis was conducted in two of the six cadavers (a male cadaver, 45 years; and a female cadaver, 51 years). Slides were made with 4-µm sections and stained with hematoxylin and eosin. RESULTS: A novel capped dens sign was detected in 39% (198 of 512) of the patients and the most typical capped dens sign was detected in 19% (96 of 512) of patients. The prevalence of this sign was the highest in patients with cervical spondylotic amyotrophy (12 of 25 patients). The prevalence of ossification of the anterior longitudinal ligament, ligamentum nuchae, and apical ligament, as well as DISH, was higher in patients with a capped dens sign than in those without (p = 0.04, p < 0.001, p < 0.001, and p = 0.001, respectively). The capped dens sign was identified in 69% (18 of 26) of the patients with DISH. A thin and short band-like structure or osteophyte was detected on MRI in 87% (26 of 30), in the same region as the capped dens sign. In the cadaveric study, an unreported, distinct ligamentous structure was identified at this ossified site. It originated from the posterosuperior rim of the anterior arch of the atlas to the inferior margin of the foramen magnum, which we called the inter-atlanto-occipital ligament. It was found in all six dissected craniocervical junctions. The histologic analysis revealed dense connective tissue. CONCLUSION: More than one-third of the patients in this series demonstrated CT evidence of a previously unrecognized ossification in the craniocervical junction, which we called the capped dens sign. Anatomic evidence of this sign, which was a previously unidentified ligament, was also newly discovered in this region. This study was conducted among Asian patients and specimens. Further studies among diverse ethnic groups may be needed to generalize the results. An additional well-designed prospective study will be needed to provide further evidence regarding the potential pathophysiology and clinical relevance of the capped dens sign. Furthermore, the cadaveric analysis in this study was only a preliminary report of the ligament; further biomechanical research is needed to investigate its function. CLINICAL RELEVANCE: Knowledge of this novel ligament may improve the diagnosis and treatment of craniocervical stability and dislocation. Ossification of this ligament is correlated with age, cervical spondylotic amyotrophy, and DISH. We wonder whether patients with cervical degenerative disorders who also have a capped dens sign may be at risk for the formation of osteophytes of an uncovertebral joint, which may result in palsy of the upper limb muscles. The capped dens sign may be the craniocervical manifestation of DISH. This possible association between the capped dens sign and DISH should be considered when performing surgery on patients with the capped dens sign.

Acute, isolated and unstable syndesmotic injuries are frequently associated with intra-articular pathologies.

PURPOSE: Although simultaneous arthroscopy for the surgical treatment of acute isolated, unstable syndesmotic injuries has been recommended, little knowledge is present about the actual frequency of intra-articular pathologies for this injury. The aim of this study was to investigate the frequency and severity of intra-articular pathologies detected during arthroscopy and their subsequent treatment in acute isolated, unstable syndesmotic injuries. METHODS: A retrospective chart review of patients treated by arthroscopic-assisted stabilization for acute isolated, syndesmotic instability was performed. The primary outcome parameter was the frequency of intra-articular pathologies. Secondary outcome parameters were the type of syndesmotic lesion (ligamentous/bony), severity of chondral lesions, MRI findings, treatment details, complications and the identification of factors associated with intra-articular pathologies. RESULTS: Twenty-seven patients, 19% female, with a mean age of 37 ± 12 years met the inclusion criteria. 70% suffered isolated ligamentous injuries, the remaining suffered avulsion fractures of the syndesmosis. Chondral lesions occurred in 48% (ICRS grade II: 33%; ICRS grade IV 15%) and intra-articular loose bodies in 11% of patients. Overall, arthroscopy revealed intra-articular pathologies necessitating further treatment in 19% of patients. Neither the type of syndesmotic injury (bony vs. ligamentous; ns) nor the degree of ligamentous instability (West Point IIB vs. III; ns) had a significant influence on the occurrence of chondral lesions. One complication (SSI) occurred. Pre-operative MRI revealed a sensitivity/specificity of 100/79% for chondral lesions and 50/93% for loose bodies. CONCLUSION: Intra-articular pathologies in acute isolated, unstable syndesmotic injuries occur in up to 50% of patients, 19% necessitated additional treatment. Simultaneous arthroscopy, independent of the pre-operative MRI findings, appears reasonable in highly active patients. LEVEL OF EVIDENCE: Level III.

Femoral and tibial bone bruise volume is not correlated with ALL injury or rotational instability in patients with ACL-deficient knee.

PURPOSE: Some researchers have suggested that bone bruises are evidence of rotational instability. The hypothesis was that the extent of lateral bone edema is correlated with the presence of an anterolateral ligament (ALL) injury. The main objective was to determine whether there was a correlation between the presence of an ALL injury the extent of bone bruises. METHODS: A prospective diagnostic study enrolled all the patients who suffered an acute anterior cruciate ligament (ACL) who were operated on within 8 weeks. The extent of bone bruising according to the ICRS classification was measured on preoperative MRIs by two independent blinded raters twice with an interval of 4 weeks. Dynamic ultrasonography (US) to look for ALL injury and the pivot shift test were performed before the ACL surgery. The correlation between ALL injury and bone bruises, and the correlation between an ALL injury and a high-grade pivot shift test were determined. RESULTS: Sixty-one patients were included; 52% of patients had an ALL injury on US. The extent of lateral bone bruise was not related to the presence of an ALL injury, nor related to the presence of a high-grade pivot shift. A grade 2 or 3 pivot shift was significantly correlated with an ALL injury (p < 0.0001). Inter- and intra-rater reliability for the bone bruise rating was excellent. CONCLUSION: The extent of lateral bone bruise is not correlated with ALL injury or a high-grade pivot shift; thus, it is not correlated with rotational instability of the knee. LEVEL OF EVIDENCE: II.

Dorsal Atlantoaxial Ligament Hypertrophy as a Cause for Clinical Signs in Dogs with Dens Abnormalities.

The objective of this study is to suggest clinical and subclinical atlantoaxial (AA) instability as a cause for dorsal AA ligament hypertrophy responsible for clinical signs in dogs with dens abnormalities. Clinical information from five dogs with malformed dens and dorsal spinal cord compression at the AA junction was collected. All dogs had neck pain, associated with tetraparesis in three cases. Radiological examination revealed hypoplastic dens in two dogs and a defect in its ossification in the other three. Stress views were able to demonstrate obvious AA instability only in two cases, but it was suspected in the other owing to response to surgical fixation of the joint and the presence of a dorsal compressive band, which was considered an enlarged dorsal AA ligament. Surgical and histopathological examination of compressive tissue confirmed hypertrophy of the ligament. Long-term prognosis in the four operated cases, either by dorsal decompression and ventral fixation or by ventral fixation alone, was excellent. A malformed dens can cause subclinical instability, unnoted in dynamic studies. As instability may lead to hypertrophy of joint ligaments, soft tissue changes (specifically dorsal AA ligament hypertrophy) points out this instability and the need for joint fixation if surgical management is required.

The tibiocalcaneal bundle of the deltoid ligament - Prevalence and variations.

INTRODUCTION: A precise understanding of the anatomy of the multiple bundles of the deltoid ankle ligament might have clinical impact. The most relevant deltoid anatomical series report a variable frequency of the tibiocalcaneal ligament, possibly the most important bundle to be reconstructed in medial ankle insufficiency. Our purpose was to access the deltoid's tibiocalcaneal ligament morphology in a large anatomical study as well as to perform a historical literature review on the reasons for its variable prevalence. MATERIALS AND METHODS: Forty-three ankle specimen were dissected to describe the prevalence of superficial and deep deltoid bundles, with special attention to the tibiocalcaneal ligament and its variants. RESULTS: All ankles had distinct deep and superficial bundles. In all 43 ankles the tibionavicular and tibiospring ligaments were clearly identified. The superficial posterior tibiotalar ligament was identified in 38 ankles (88%). The deep anterior tibiotalar bundle was identified in 35 ankles (81%). The deep posterior tibiotalar bundle was identified in all ankles. The tibiocalcaneal ligament was identified in 33 ankles (77%). In ten ankles there wasn't a direct bundle between the tibia and the sustentaculum tali. In all of these, however, we found some fibers spanning the gap between the tibiospring ligament and the sustentaculum tali. CONCLUSION: The tibiocalcaneal ligament is present in most specimens. In those in which we could not identify a direct bundle between the tibia and the calcareous we found a variant of the tibiospring ligament that connects to the sustentaculum tali.

MRI assessment of anatomy and pathology of the iliofemoral ligament.

The iliofemoral ligament is strongest ligament of the body. We review the magnetic resonance imaging (MRI) appearances of the iliofemoral ligament, and discuss the disease entities that may affect this region.

Accuracy of unguided and ultrasound guided Coracohumeral ligament infiltrations - a feasibility cadaveric case series.

BACKGROUND: Coracohumeral ligament (CHL) thickening, contracture, and fibroplasia have been identified in glenohumeral idiopathic adhesive capsulitis (GHIAC). The CHL is the main structure responsible for the range of motion limitations. Favorable outcomes have been reported with CHL surgical release. Intra-articular glenohumeral joint corticosteroid infiltrations are utilized to disrupt the inflammatory process and reduce pain in GHIAC. The aim of this study was to investigate whether the CHL could be accurately targeted with a periligamentous infiltration. METHODS: A convenience sample of 12 unembalmed cadaver shoulders (mean age: 74.5 years, range 66-87 years) without evidence of previous injury or surgery were utilized in this exploratory double factor feasibility cadaveric (unguided and ultrasound (US) guided) case series. Two clinicians trained in musculoskeletal infiltration techniques carried out the infiltrations on each shoulder with colored latex. One clinician infiltrated without guidance, the other with US-guidance. The injecting clinicians were blinded to the others infiltration procedure and the order was randomized. An anatomist blinded to the infiltration order performed a shoulder dissection and recorded the infiltrate location. Percentage calculation for accuracy of infiltration and a chi-square evaluation of the difference between unguided and US-guided infiltrations was applied. RESULTS: An accuracy of 75% was achieved for unguided infiltration and 80% for US-guided infiltration techniques. Chi-squared indicated there was no significant difference (p = 0.82) between the unguided and US-guided techniques. CONCLUSION: US-guided and unguided infiltrations achieved good accuracy targeting the CHL, suggesting infiltrations can specifically and accurately target the CHL. In vivo investigation using such infiltration techniques are warranted.

Atlanto-occipital ligament calcification: a novel imaging finding in pediatric rotational vertebral artery occlusion.

We describe a 2-year-old girl with bow hunter syndrome complicated by vertebral artery dissection and multiple ischemic infarcts. Pediatric bow hunter syndrome is a rare and likely under-recognized disorder. Interestingly, our patient had atlanto-occipital ligament calcification on CT scan, an imaging finding that has not been reported in association with bow hunter syndrome and one that might help increase recognition of this dynamic disorder of the posterior circulation.

The majority of patellar avulsion fractures in first-time acute patellar dislocations included the inferomedial patellar border that was different from the medial patellofemoral ligament attachment.

PURPOSE: Accurate assessment of the locations of patellar avulsion fractures in acute patellar dislocations is clinically relevant for decision making for treatment. The study aim was to classify the locations of patellar avulsion fractures with a focus on the ligament attachments of medial stabilizing structures. METHODS: Out of 131 first-time acute traumatic patellar dislocations, 61 patients had patellar fractures. Subsequently, 10 patients with isolated osteochondral fractures of the articular surface in the patella were excluded. Finally, 51 patients (34 females and 17 males, average age: 18.5 years, 95% CI 16.1-20.9) were included in the study cohort. Based on the locations of the patellar attachment, the patients were divided into three groups: the superior group [medial patellofemoral ligament (MPFL) attachment], inferior group [medial patellotibial ligament (MPTL)/medial patellomeniscal ligament (MPML) attachment], and mixed group. RESULTS: In the patellar avulsion group (51 patients), the superior group, mixed group, and inferior group contained 8/51 (16%), 12/51 (24%), and 31/51 (61%) patients, respectively. CONCLUSIONS: This study showed that 84% of the patellar avulsion fractures were located in the inferomedial patellar border, which consisted of MPTL/MPML attachments that were clearly different from the true "MPFL" attachment at the superomedial patellar border. In terms of the clinical relevance, the acute surgical repair of MPTL/MPML attachments in the inferomedial patellar border may not sufficiently control the patella if optimal management of the MPFL is not performed. LEVEL OF EVIDENCE: IV.

Systematic review and meta-analysis of magnetic resonance imaging features for diagnosis of adhesive capsulitis of the shoulder.

OBJECTIVES: To perform a systematic review and meta-analysis to identify magnetic resonance imaging (MRI) features that will aid in the diagnosis of adhesive capsulitis of the shoulder (ACS) and provide a summary of the diagnostic accuracy of the identified features METHODS: The MEDLINE and EMBASE databases were searched for studies assessing the diagnostic accuracy of MRI features of ACS. Overlapping descriptors used to denote the same imaging finding in different studies were subsumed under a single feature. The pooled accuracy including the diagnostic odd ratios (DORs) with 95% confidence intervals (CIs) of the identified features was calculated using a bivariate random-effects model. RESULTS: In total, 15 studies were included, and 74 overlapping descriptors were subsumed under six features. All six features were found to be informative for ACS diagnosis [coracohumeral ligament thickening: DOR, 13; 95% CI, 6-29; fat obliteration of the rotator interval (RI): DOR, 8; 95% CI, 3-24; RI enhancement: DOR, 44; 95% CI, 14-141; axillary joint capsule enhancement: DOR, 52; 95% CI, 27-98; inferior glenohumeral ligament (IGHL) hyperintensity: DOR, 31; 95% CI, 8-115; IGHL thickening: DOR, 28; 95% CI, 11-70]. The sensitivity and specificity of enhancement of the RI and axillary joint capsule and IGHL hyperintensity were > 80%. CONCLUSIONS: Six informative MRI features for ACS diagnosis were identified in this study with RI and axillary joint capsule enhancement and IGHL hyperintensity showing the highest diagnostic accuracy. Informative features observed on non-arthrogram MRI can be as helpful as features observed on direct magnetic resonance arthrography for ACS diagnosis. KEY POINTS: • Six informative MRI features for ACS diagnosis were identified (diagnostic odds ratio > 1). • RI and axillary joint capsule enhancement and IGHL hyperintensity showed high sensitivities/specificities (> 80%). • The use of non-arthrogram MRI is recommended for ACS diagnosis.

Evaluation of anterior intermeniscal ligament in discoid lateral meniscus cases and presenting the accompanying meniscal pathologies with MRI.

BACKGROUND: Although several studies were conducted to put forth the biomechanical function of anterior intermeniscal ligament (AIML) on the stability of meniscal structures, there are few data on the etiology of the early degeneration of discoid type compared to the normal shaped ones. PURPOSE: To determine the AIML subtypes and accompanying meniscal pathologies in discoid lateral menisci (DLM) on knee MRI exams. MATERIAL AND METHODS: Knee MRI exams of 171 individuals with DLM were reviewed. DLMs and AIMLs were typed according to Watanabe's classification and Nelson-Laprade classification, respectively. Medial and lateral menisci were evaluated for tear and menisco-capsular pathology. Pearson's correlation test was used for statistical analysis. RESULTS: DLM was type I in 83 (48.5%) individuals and type II in 88 (51.5%) individuals. AIML was absent in 90 (52.6%) participants; type I AIML was seen in 38 out 81 (22.2%), type II in 31 out of 81(18.1%), and type III in 12 out of 81 (7%). Meniscal pathology was observed in 56 (32.7%) individuals as follows: menisco-capsular strain/separation in 25 (14.6%); medial meniscal tear in 22 (12.8%); and lateral meniscal tear in nine (5.2%); Of these 56 cases, 26 (46%) had no AIML, 15 cases (27%) had type I, nine cases (16%) had type II, and six cases (11%) had type III AIML. CONCLUSION: No statistically significant correlation was found between the type of DLM and type of AIML ( P = 0.855), between the type of DLM and meniscal pathology ( P = 0.791), or between the type of AIML and meniscal pathology ( P = 0.282).

Radiographic analysis of the correlation between ossification of the nuchal ligament and sagittal alignment and segmental stability of the cervical spine in patients with cervical spondylotic myelopathy.

BACKGROUND: Ossification of the nuchal ligament (ONL) caused by chronic injury to the nuchal ligament (NL) is very common in instability-related cervical disorders. PURPOSE: To determine possible correlations between ONL, sagittal alignment, and segmental stability of the cervical spine. MATERIAL AND METHODS: Seventy-three patients with cervical spondylotic myelopathy (CSM) and ONL (ONL group) and 118 patients with CSM only (control group) were recruited. Radiographic data included the characteristics of ONL, sagittal alignment and segmental stability, and ossification of the posterior longitudinal ligament (OPLL). We performed comparisons in terms of radiographic parameters between the ONL and control groups. The correlations between ONL size, cervical sagittal alignment, and segmental stability were analyzed. Multivariate logistic regression was used to identify the independent risk factors of the development of ONL. RESULTS: C2-C7 sagittal vertical axis (SVA), T1 slope (T1S), T1S minus cervical lordosis (T1S-CL) on the lateral plain, angular displacement (AD), and horizontal displacement (HD) on the dynamic radiograph increased significantly in the ONL group compared with the control group. The size of ONL significantly correlated with C2-C7 SVA, T1S, AD, and HD. The incidence of ONL was higher in patients with OPLL and segmental instability. Cervical instability, sagittal malalignment, and OPLL were independent predictors of the development of ONL through multivariate analysis. CONCLUSION: Patients with ONL are more likely to have abnormal sagittal alignment and instability of the cervical spine. Thus, increased awareness and appreciation of this often-overlooked radiographic finding is warranted during diagnosis and treatment of instability-related cervical pathologies and injuries.