Bone bruise distribution predicts anterior cruciate ligament tear location in non-contact injuries

Purpose

It is unclear whether different injury mechanisms lead to divergent anterior cruciate ligament (ACL) tear locations. This study aims to analyse the relationship between bone bruise (BB) distribution or depth and ACL tear location.

Methods

A retrospective analysis of 446 consecutive patients with acute non-contact ACL injury was performed. Only patients with complete ACL tears verified during subsequent arthroscopy were included. Magnetic resonance imaging (MRI) was used to classify BB location, BB depth, ACL tear location and concomitant injuries (medial/lateral meniscus and medial/lateral collateral ligament). Demographic characteristics included age, gender, body mass index (BMI), type of sport and time between injury and MRI. Multiple linear regression analysis was used to identify independent predictors of ACL tear location.

Results

One hundred and fifty-eight skeletally mature patients met the inclusion criteria. The presence of BB in the lateral tibial plateau was associated with a more distal ACL tear location (β = -0.27, p < 0.001). Less BB depth in the lateral femoral condyle showed a tendency towards more proximal ACL tears (β = -0.14; p = 0.054). Older age predicted a more proximal ACL tear location (β = 0.31, p < 0.001). No significant relationship was found between ACL tear location and gender, BMI, type of sport, concomitant injuries and time between injury and MRI.

Conclusion

ACL tear location after an acute non-contact injury is associated with distinct patterns of BB distribution, particularly involving the lateral compartment, indicating that different injury mechanisms may lead to different ACL tear locations.

Level of Evidence

Level III.

Post-mortem feasibility of dual-energy computed tomography in the detection of bone edema-like lesions in the equine foot: a proof of concept

Introduction

In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI).

Methods

A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the detection of bone edema-like lesions. A gross post-mortem was performed, and histopathologic samples were obtained of the navicular and/or distal phalanx of the two feet selected based on pathology and one reference foot.

Results

On DECT virtual non-calcium imaging, the two pathological feet showed diffuse increased attenuation corresponding with bone edema-like lesions, whereas the three reference feet were considered normal. These findings were in agreement with the findings on the MRI. Histopathology of the two pathologic feet showed abnormalities in line with bone edema-like lesions. Histopathology of the reference foot was normal.

Conclusion

DECT virtual non-calcium imaging can be a valuable diagnostic tool in the diagnosis of bone edema-like lesions in the equine foot. Further examination of DECT in equine diagnostic imaging is warranted in a larger cohort, different locations, and alive animals.

The Predicted Position of the Knee Near the Time of ACL Rupture Is Similar Between 2 Commonly Observed Patterns of Bone Bruising on MRI

BACKGROUND

Bone bruises observed on magnetic resonance imaging (MRI) can provide insight into the mechanisms of noncontact anterior cruciate ligament (ACL) injury. However, it remains unclear whether the position of the knee near the time of injury differs between patients evaluated with different patterns of bone bruising, particularly with regard to valgus angles.

HYPOTHESIS

The position of the knee near the time of injury is similar between patients evaluated with 2 commonly occurring patterns of bone bruising.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Clinical T2- and T1-weighted MRI scans obtained within 6 weeks of noncontact ACL rupture were reviewed. Patients had either 3 (n = 20) or 4 (n = 30) bone bruises. Patients in the 4-bone bruise group had bruising of the medial and lateral compartments of the femur and tibia, whereas patients in the 3-bone bruise group did not have a bruise on the medial femoral condyle. The outer contours of the bones and associated bruises were segmented from the MRI scans and used to create 3-dimensional surface models. For each patient, the position of the knee near the time of injury was predicted by moving the tibial model relative to the femoral model to maximize the overlap of the tibiofemoral bone bruises. Logistic regressions (adjusted for sex, age, and presence of medial collateral ligament injury) were used to assess relationships between predicted injury position (quantified in terms of knee flexion angle, valgus angle, internal rotation angle, and anterior tibial translation) and bone bruise group.

RESULTS

The predicted injury position for patients in both groups involved a flexion angle <20°, anterior translation >20 mm, valgus angle <10°, and internal rotation angle <10°. The injury position for the 3-bone bruise group involved less flexion (odds ratio [OR], 0.914; 95% CI, 0.846-0.987; P = .02) and internal rotation (OR, 0.832; 95% CI, 0.739-0.937; P = .002) as compared with patients with 4 bone bruises.

CONCLUSION

The predicted position of injury for patients displaying both 3 and 4 bone bruises involved substantial anterior tibial translation (>20 mm), with the knee in a straight position in both the sagittal (<20°) and the coronal (<10°) planes.

CLINICAL RELEVANCE

Landing on a straight knee with subsequent anterior tibial translation is a potential mechanism of noncontact ACL injury.

Identifying Clinical and MRI Characteristics Associated with Quality of Life in Patients with Anterior Cruciate Ligament Injury: Prognostic Factors for Long-Term

BACKGROUND

Associated lesions in the diagnostic MRI may be related to worse long-term subjective outcomes. There is a lack of conclusive information about the long-term outcomes of associated injuries in anterior cruciate ligament (ACL) tears. The purpose of this study is to assess the long-term effects of associated injuries in ACL tears measured by means of a quality of life (QOL) assessment.

METHODS

A retrospective cohort study of 225 consecutive patients admitted for physical therapy with ACL injury (42 ± 12 years, 28.2% female) were conducted. All demographic and clinical variables were used to measure a QOL. Univariate and multivariable analyses were completed.

RESULTS

The mean follow-up period was 8.4 ± 2.6 years. In univariate analysis, male gender, and sports as the cause of the ACL lesion were factors significantly associated with improved International Knee Documentation Committee (IKDC) scores at the end of follow-up (all p < 0.002). In multivariable analysis, the occurrence of bone contusion was positively associated with injury (OR = 2.12) and negatively associated with sports injury (OR = 0.44) and medial collateral ligament (MCL) injury (OR = 0.48).

CONCLUSIONS

After ACL injury, male gender and sports injury were associated with better clinical outcomes.

Distribution of Bone Contusion Patterns in Acute Noncontact Anterior Cruciate Ligament-Torn Knees

BACKGROUND

Bone contusions are commonly observed on magnetic resonance imaging (MRI) in individuals who have sustained a noncontact anterior cruciate ligament (ACL) injury. Time from injury to image acquisition affects the ability to visualize these bone contusions, as contusions resolve with time.

PURPOSE

To quantify the number of bone contusions and their locations (lateral tibial plateau [LTP], lateral femoral condyle [LFC], medial tibial plateau [MTP], and medial femoral condyle [MFC]) observed on MRI scans of noncontact ACL-injured knees acquired within 6 weeks of injury.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We retrospectively reviewed clinic notes, operative notes, and imaging of 136 patients undergoing ACL reconstruction. The following exclusion criteria were applied: MRI scans acquired beyond 6 weeks after injury, contact ACL injury, and previous knee trauma. Fat-suppressed fast spin-echo T2-weighted MRI scans were reviewed by a blinded musculoskeletal radiologist. The number of contusions and their locations (LTP, LFC, MTP, and MFC) were recorded.

RESULTS

Contusions were observed in 135 of 136 patients. Eight patients (6%) had 1 contusion, 39 (29%) had 2, 41 (30%) had 3, and 47 (35%) had 4. The most common contusion patterns within each of these groups were 6 (75%) with LTP for 1 contusion, 29 (74%) with LTP/LFC for 2 contusions, 33 (80%) with LTP/LFC/MTP for 3 contusions, and 47 (100%) with LTP/LFC/MTP/MFC for 4 contusions. No sex differences were detected in contusion frequency in the 4 locations (P > .05). Among the participants, 50 (37%) had medial meniscal tears and 52 (38%) had lateral meniscal tears.

CONCLUSION

The most common contusion patterns observed were 4 locations (LTP/LFC/MTP/MFC) and 3 locations (LTP/LFC/MTP).

Analysis of Risk Factors for Ramp Lesions Associated With Anterior Cruciate Ligament Injury

BACKGROUND

The incidence of meniscocapsular junction tears of the medial meniscus posterior horn, known as ramp lesions, is reported to be 9.3% to 23.9%. However, these lesions are not consistently diagnosed with routine arthroscopic exploration and magnetic resonance imaging (MRI).

PURPOSE

To determine risk factors associated with ramp lesions in anterior cruciate ligament-injured knees.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 275 patients undergoing anterior cruciate ligament reconstruction between June 2011 and March 2019 were included in this study. Exclusion criteria were revisions, fracture histories, and multiple-ligament injuries other than medial collateral ligament injury. Patients were divided into 2 groups, those with and without ramp lesions according to arthroscopic diagnosis. Binary logistic regression was used to analyze risk factors: age, sex, body mass index, time from injury to surgery (<3 or ≥3 months), mechanism of injury (contact/noncontact), Segond fracture, side-to-side laxity, location of bone contusion, medial and lateral tibial/meniscal slope, and mechanical axis angle. Receiver operating characteristic curves and area under the curve were evaluated. A prediction model was developed by multivariable regression with generalized estimating equations.

RESULTS

Overall, 95 patients (34.5%) were confirmed as having a ramp lesion. The sensitivity of MRI for ramp lesions was 85.3%, and specificity was 78.3%. Significant risk factors for ramp lesion were as follows: posterior medial tibial plateau bone contusion on MRI (odds ratio [OR], 4.201; 95% CI, 2.081-8.482; P < .001), ≥3 months from injury (OR, 4.818; 95% CI, 2.158-10.757; P < .001), varus knee >3° (OR, 2.339; 95% CI, 1.048-5.217; P = .038), steeper medial tibial slope (OR, 1.289; 95% CI, 1.002-1.66; P = .049) and meniscal slope (OR, 1.464; 95% CI, 1.137-1.884; P = .003), and gradual lateral tibial slope (OR, 0.775; 95% CI, 0.657-0.914; P = .002). The area under the curve for the prediction model developed by logistic regression was 0.779 (sensitivity, 75.8%; specificity, 71.7%; P < .001) for ramp lesions.

CONCLUSION

Care should be taken with patients who have significant risk factors for ramp lesions, including bone contusion at the posterior medial tibial plateau, chronic injury, steeper medial tibial and meniscal slope, gradual lateral tibial slope, and varus knee >3°.

Evaluation of Anterolateral Ligament Healing After Anatomic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Few studies have reported the healing process of anterolateral ligament (ALL) injuries.

PURPOSE/HYPOTHESIS

This study investigated the healing status of ALL injuries after primary anterior cruciate ligament (ACL) reconstruction (ACLR). Additionally, we investigated the association between the healing status of ALL injuries and associated lesions such as osseous lesions and meniscal tears occurring at the time of an ACL rupture. We hypothesized that acute ALL injuries show a high rate (more than two-thirds) of healing at the 1-year follow-up after ACLR and that concomitant lesions observed at the time of an ACL rupture affect the healing status of the ALL.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

We retrospectively investigated patients with ALL injuries who underwent primary ACLR between March 2015 and February 2017. Using magnetic resonance imaging (MRI), we evaluated the features of ALL injuries and concomitant lesions, and MRI was performed at the 1-year follow-up to assess the healing status of the ALL. We investigated the association between the healing status of the ALL and concomitant lesions observed at the time of an ACL rupture. A subjective assessment was performed using the Lysholm score, International Knee Documentation Committee subjective score, and Tegner activity scale. Objective tests included an isokinetic strength assessment and functional performance testing.

RESULTS

With respect to the severity of ALL injuries, of 54 patients, a complete rupture occurred in 16 (29.6%) of the 54 patients and a partial rupture in 38 (70%). A significant association was observed between the severity of ALL injuries and bone contusions (lateral tibial plateau and medial tibial plateau [MTP]) and meniscus ramp lesions (Fisher exact test: P = .023, .012, and .023, respectively). Good and partial healing of the ALL occurred in 16 (29.6%) and 23 (42.6%) of 54 patients, respectively. Scar formation occurred in 12 (22.2%), and nonvisualization of the ALL was observed in 3 (5.6%) of 54 patients. Poor healing of the ALL was associated with preoperative MTP bone contusions and a high-grade pivot shift. Multivariate analysis showed that an MTP bone contusion was an independent risk factor associated with poor healing of the ALL. Among the functional tests performed, significant differences were observed between the good and poor healing groups with respect to the carioca test (P = .039). The good healing group (n = 16) showed a negative pivot shift at the last follow-up, whereas 5 (13.2%) of the patients from the poor healing group (n = 38) showed a positive pivot shift, including 2 (5.3%) with a high-grade pivot shift.

CONCLUSION

Approximately 70% of acute ALL injuries showed poor healing at the 1-year follow-up. Poor healing of ALL injuries was significantly associated with preoperative MTP bone contusions and a high-grade pivot shift. Therefore, a careful assessment of posteromedial bone contusions at the time of an ACL rupture is warranted, particularly in patients with a high-grade pivot shift.

Sex Difference in Contusion of the Medial Femoral Condyle Rim-Association with MRI Occult Meniscal Tears in the ACL Deficient Knee

BACKGROUND

Meniscal tears, specifically lateral meniscal tears, have a larger than expected un-derdiagnosis rate in the presence of an ACL tear. The purpose of our study was to search for an MRI bone contusion pattern associated with MRI occult meniscal tears in patients with an ACL tear, specifically a contusion of the rim of the medial femoral condyle (RMFC). Our hypothesis was that there would be a significant association between RMFC contusions and MRI occult meniscal tears in patients with an ACL tear. We also searched for a difference between sexes with respect to the presence of the RMFC contusion in the setting of an occult meniscal tear. We also categorized the type, size, and location of these occult meniscal tears in the setting of an ACL tear.

METHODS

This was a retrospective study that examined characteristics of occult meniscal tears and their association with a RMFC bone contusion. IRB approval was obtained. The date range of the study was June 2009 through December 2015. 6392 consecutive knee MRI reports in patients with an ACL deficient knee were reviewed. The study group included 22 patients with MRI occult meniscal tears, the control group included 110 patients. Relevant statistical values were calculated.

RESULTS

The most common type of occult meniscal tears were small radial and small longitudinal tears of the lateral meniscus. Occult meniscal tears were associated with an RMFC contusion in the study group (p=0.0457), particularly in males (p = 0.0003). In males with a torn ACL, the sensitivity of an RMFC contusion for an occult meniscal tear was 80%.

CONCLUSION

In males with an ACL tear, there was a significant association between a contusion of the RMFC and an occult meniscal tear (commonly small radial or small peripheral partial-thickness longitudinal tears). RMFC contusions were reliably identified by radiologists in this study.Level of Evidence: II.

Diagnostic Value of Early Magnetic Resonance Imaging After Acute Lateral Ankle Injury

We report a retrospective study of 171 consecutive patients with a lateral ankle sprain. All the patients with direct or blunt force trauma were excluded. Within 21 days of injury, 115 (67.25%) patients had undergone magnetic resonance imaging to evaluate for more serious or significant injuries. The average patient age was 44.09 years. Of the 115 patients, 75 (65.23%) had findings noted to be "significant." MRI can serve as a valuable and underused tool in the evaluation of acute lateral ankle injuries. The underuse of MRI might explain the high degree of variability in patients recovering from a lateral ankle sprain.

Determination of the Position of the Knee at the Time of an Anterior Cruciate Ligament Rupture for Male Versus Female Patients by an Analysis of Bone Bruises

BACKGROUND

The incidence of anterior cruciate ligament (ACL) ruptures is 2 to 4 times higher in female athletes as compared with their male counterparts. As a result, a number of recent studies have addressed the hypothesis that female and male patients sustain ACL injuries via different mechanisms. The efficacy of prevention programs may be improved by a better understanding of whether there are differences in the injury mechanism between sexes. Hypothesis/Purpose: To compare knee positions at the time of a noncontact ACL injury between sexes. It was hypothesized that there would be no differences in the position of injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

Clinical T2-weighted magnetic resonance imaging (MRI) scans from 30 participants (15 male and 15 female) with a noncontact ACL rupture were reviewed retrospectively. MRI scans were obtained within 1 month of injury. Participants had contusions associated with an ACL injury on both the medial and lateral articular surfaces of the femur and tibia. Three-dimensional models of the femur, tibia, and associated bone bruises were created via segmentation on MRI. The femur was positioned relative to the tibia to maximize bone bruise overlap, thereby predicting the bone positions near the time of the injury. Flexion, valgus, internal tibial rotation, and anterior tibial translation were measured in the predicted position of injury.

RESULTS

No statistically significant differences between male and female patients were detected in the position of injury with regard to knee flexion ( P = .66), valgus ( P = .87), internal tibial rotation ( P = .26), or anterior tibial translation ( P = .18).

CONCLUSION

These findings suggest that a similar mechanism results in an ACL rupture in both male and female athletes with this pattern of bone bruising.

CLINICAL RELEVANCE

This study provides a novel comparison of male and female knee positions at the time of an ACL injury that may offer information to improve injury prevention strategies.

What Injury Mechanism and Patterns of Ligament Status Are Associated With Isolated Coronoid, Isolated Radial Head, and Combined Fractures?

BACKGROUND

Isolated coronoid, isolated radial head, and combined coronoid and radial head fractures are common elbow fractures, and specific ligamentous injury of each fracture configuration has been reported. However, the osseous injury mechanism related to ligament status remains unclear.

QUESTIONS/PURPOSES

The objectives of this study were: (1) to determine what ligamentous injury patterns (medial or lateral collateral) and bone contusion patterns (medial or lateral) are associated with isolated coronoid, isolated radial head, and combined coronoid and radial head fractures; (2) to correlate the osseous injury mechanism based on these findings with isolated coronoid, isolated radial head, and combined coronoid and radial head fractures; and (3) to determine whether isolated and combined coronoid fractures have different fracture lines through the coronoid (tip or anteromedial facet), speculated to be caused by different injury mechanisms.

METHODS

Between June 2007 and June 2012, 100 patients with elbow fractures were included in the cohort, with 46 of these patients being excluded owing to incongruity for our surgical indication. Finally, 54 patients with surgically treated elbow fractures who had MRI preoperatively were assessed retrospectively. There were 17 elbows with isolated coronoid fractures, 22 with isolated radial head fractures, and 15 with combined coronoid and radial head fractures. Collateral ligament injury pattern and existence of distal humerus bone contusion were reviewed on MR images.

RESULTS

Patients with isolated radial head fractures were at greater risk of medial collateral ligament rupture compared with patients with isolated coronoid fractures (radial head only: 15 of 22 [68%]; coronoid only: three of 17 [18%]; odds ratio [OR], 10.0; 95% CI, 2.2-46.5; p = 0.002). Patients with isolated coronoid fractures had greater risk of lateral ulnar collateral ligament ruptures (coronoid: 16 of 17 [94%]; radial head: seven of 22 [32%]; OR, 3.5; 95% CI, 3.8-333.3; p < 0.001). The presence of radial head fractures was associated with the risk of lateral bone bruising (isolated radial head fracture: 32 of 37 [86%], isolated coronoid fracture: four of 17 [24%]; OR, 29.6; 95% CI, 5.2-168.9; p < 0.001). Medial bone bruising was only detected in isolated coronoid fractures (isolated coronoid fracture: 12 of 17 [71%], others: zero of 37 [0%]). All isolated coronoid fractures involved the anteromedial facet of the coronoid (17 of 17; 100%). However, combined coronoid and radial head fractures often involved the tip (13 of 15; 87%).

CONCLUSIONS

Isolated coronoid fractures mostly involved the anteromedial facet of the coronoid process associated with lateral ulnar collateral ligament rupture and medial bone bruising. However, isolated radial head fractures were associated with medial collateral ligament rupture and lateral bone bruising. Combined coronoid and radial head fractures mostly involved a tip fracture of the coronoid with lateral ulnar collateral ligament rupture and lateral bone bruising. Thus surgeons may predict which ligament they should be aware of in the surgical field.

LEVEL OF EVIDENCE

Level III, prognostic study.

Bone contusion progression from traumatic knee injury: association of rate of contusion resolution with injury severity

BACKGROUND

Bone contusions are frequently encountered in magnetic resonance imaging (MRI) evaluation of knee anterior cruciate ligament (ACL) injuries. Their role as indicators of injury severity remains unclear, primarily due to indeterminate levels of joint injury forces and to a lack of preinjury imaging.

PURPOSE

The purpose of this study was to 1) quantify bone contusion pathogenesis following traumatic joint injuries using fixed imaging follow-ups, and 2) assess the feasibility of using longitudinal bone contusion volumes as an indicator of knee injury severity.

STUDY DESIGN

Prospective sequential MRI follow-ups of a goat cohort exposed to controlled stifle trauma in vivo were compared to parallel clinical MRI follow-ups of a human ACL tear patient series.

METHODS

Reproducible cartilage impact damage of various energy magnitudes was applied in a survival goat model, coupled with partial resection of anterior portions of medial menisci. Both emulate injury patterns to the knee osteochondral structures commonly encountered in human ACL injury imaging as well as instability from resultant ligament laxity. Longitudinal clinical MRI sequences portrayed stifle bone contusion evolution through 6 months after the inciting event.

RESULTS

In the first 2 weeks, biological response variability dominated the whole-joint response with no apparent correlation to trauma severity. Control goats subjected to partial meniscectomy alone exhibited minimal bone response. Thereafter, 0.6 J impact bone contusions portrayed a faster rate of resolution than those induced by 1.2 J cartilage impacts.

CONCLUSION

Bone contusion sizes combined with time of persistence are likely better measures of joint injury severity than isolated bone contusion volume.

Subradiographic Foot and Ankle Fractures and Bone Contusions Detected by MRI in Elite Ice Hockey Players

BACKGROUND

In ice hockey players, serious bone injuries in the foot and ankle, especially those attributed to impact from the moving puck, may be radiographically occult and underrecognized.

PURPOSE/HYPOTHESIS

The purpose of this research was to study foot and ankle bone injuries detected with magnetic resonance imaging (MRI) that occurred in elite hockey players. The hypothesis was that these injuries predominate medially, especially when caused by the impact from the puck, and are associated with prolonged lost playing time.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Three independent observers, blinded to the mechanism of injury, retrospectively reviewed foot and ankle MRI examinations acquired after 31 acute injuries that occurred in 27 elite ice hockey players who had no radiographically visible fractures. Bone abnormalities were classified as fractures or varying degrees of contusion based on predetermined definitions. Interobserver agreement was analyzed with kappa statistics. The association between the injury mechanism and the bones involved was examined with the Fisher exact test. A t test was applied to determine if MRI evidence of a severe bone injury (defined as either a fracture or a high-grade bone contusion) was associated with longer recovery times, when return-to-play information was available.

RESULTS

The observers identified at least 1 bone injury in 27 of the 31 MRI examinations, including 10 with radiographically occult fractures. Agreement among the 3 observers for injury categorization was substantial (κ = 0.76). Seventeen injuries were caused by a direct blow (15 from a moving puck, 2 from an uncertain source), resulting in 6 fractures and 6 high-grade bone contusions, with 14 of the 17 involving a medial bone (medial malleolus, navicular, or first metatarsal base). Compared with other mechanisms, direct impaction was statistically more likely to result in a severe bone injury and to involve the medial foot and ankle. In 20 injuries where return-to-play information was available, players with severe bone injuries missed a mean of 10.6 games compared with 2.4 games for other players (P = .05).

CONCLUSION

MRI can show severe bone injuries that are not visible radiographically in ice hockey players. Most fractures and high-grade contusions involve the medial ankle and midfoot bones, can be caused by direct blows from the puck, and are associated with prolonged recovery times.