Distal Patellar Tendon Avulsion Associated with an ACL Tear in a Teenager: A Case Report and Review of the Literature

Distal patellar tendon avulsions are rare injuries in healthy individuals, and to date, no case affecting skeletally mature teenagers and adolescents has been reported. In the majority of cases, distal patellar tendon avulsions are associated with severe intra-articular knee lesions, signifying a high-energy trauma. We present the case of a 15.5-year-old female who was admitted to the emergency department after a knee injury. The mechanism of injury was a combination of landing after a jump off a scooter and sudden deceleration with a fixed foot. Lateral radiographs revealed a distal patellar tendon avulsion. An MRI was conducted to accurately diagnose concomitant lesions. The MRI revealed a complete tear of the ACL, and associated bone bruises on the lateral femoral condyle, and also on the posterolateral tibial plateau. A knee joint exam under general anesthesia demonstrated good stability during valgus stress testing and only a grade 1 positive Lachman test. Therefore, we decided to only reconstruct the extensor mechanism and to abstain from a primary ACL reconstruction. The presented case and review of the literature demonstrate the clinical relevance of this atypical lesion. In fact, a distal patellar tendon avulsion after physeal fusion of the proximal tibia should raise a strong suspicion of severe associated intra-articular knee lesions and requires prompt MRI investigation. However, controversy still exists regarding the management of these injuries, in particular concerning the question of whether to address both injuries in a single stage or in 2 stages.

Clinical Implications of Bone Bruise Patterns Accompanying Anterior Cruciate Ligament Tears

Background: Anterior cruciate ligament (ACL) tears are common injuries; they are often associated with concomitant injuries to other structures in the knee, including bone bruises. While there is limited evidence that bone bruises are associated with slightly worse clinical outcomes, the implications of bone bruises for the articular cartilage and the risk of developing osteoarthritis (OA) in the knee are less clear. Recent studies suggest that the bone bruise pattern may be helpful in predicting the presence of meniscal ramp lesions. Evidence Acquisition: A literature review was performed in EMBASE using the keyword search phrase (acl OR (anterior AND cruciate AND ligament)) AND ((bone AND bruise) OR (bone AND contusion) OR (bone AND marrow AND edema) OR (bone AND marrow AND lesion) OR (subchondral AND edema)). Study Design: Clinical review. Level of Evidence: Level 4. Results: The literature search returned 93 articles of which 25 were ultimately included in this review. Most studies identified a high prevalence of bone bruises in the setting of acute ACL injury. Individual studies have found relationships between bone bruise volume and functional outcomes; however, these results were not supported by systematic review. Similarly, the literature has contradictory findings on the relationship between bone bruises and the progression of OA after ACL reconstruction. Investigations into concomitant injury found anterolateral ligament and meniscal ramp lesions to be associated with bone bruise presence on magnetic resonance imaging. Conclusion: Despite the ample literature identifying the prevalence of bone bruises in association with ACL injury, there is little evidence to correlate bone bruises to functional outcomes or progression of OA. Bone bruises may best be used as a marker for concomitant injury such as medial meniscal ramp lesions that are not always well visualized on magnetic resonance imaging. Further research is required to establish the longitudinal effects of bone bruises on ACL tear recovery. Strength of Recommendation Taxonomy: 2.

Comparison Between Soccer and Basketball of Bone Bruise and Meniscal Injury Patterns in Anterior Cruciate Ligament Injuries

Background: The varying effectiveness of anterior cruciate ligament (ACL) injury prevention programs between soccer and basketball may be due to differences in sport-specific injury mechanisms. Bone bruise patterns may provide information regarding injury mechanisms. Purpose: To compare bone bruise and meniscal injury patterns for ACL injuries sustained in soccer versus basketball. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Clinical notes, operative reports, and magnetic resonance imaging scans were reviewed for patients who sustained a noncontact ACL rupture while playing soccer or basketball between August 2016 and August 2018. The presence, location, and signal intensity of bone bruises on the tibia and femur were documented, and patterns were classified according to the location of the bone bruise in the lateral-medial direction. The meniscal and bone bruise injury patterns and the specific bone bruise locations were compared between the soccer and basketball groups. Results: Overall, 138 patients were included (56 with soccer-related and 82 with basketball-related ACL injury). No significant difference between the groups was observed in bone bruise patterns ( P = .743) or meniscal injury patterns ( P = .952). Bone bruise on the lateral side only of both the femur and the tibia was the most common pattern in both soccer (41.9%) and basketball (47.0%) groups; the most common meniscal injury type was an isolated lateral meniscal injury in both soccer (50.0%) and basketball (45.0%) groups. For patients with bone bruises on both the lateral and the medial sides of both the femur and the tibia (BF+BT), the bone bruise signal intensity on the lateral side of the femur ( P < .001) and tibia ( P = .009) was significantly higher than that on the medial side for both groups. The bone bruises on the lateral side of the femur ( P < .001) and tibia ( P = .002) were significantly more anterior than those on the medial side for patients with the BF+BT pattern. Conclusion: No significant differences in bone bruise location or meniscal injury type were detected when comparing ACL injuries sustained during soccer versus basketball. The study results suggest a similar biomechanical loading pattern for ACL injuries in these sports.

The Influence of Bone Bruises on Bone Tunnel Enlargement Regarding ACL Rupture

Purpose: The purpose was to determine the impact of the size of bone bruises (BBs) on bone tunnel enlargement (BTE) occurrence. Materials and methods: Twenty-four (24) patients who underwent anterior cruciate ligament reconstruction (ACLR) were included in this retrospective study. The measurements of BBs based on the initial MRI scan, bone tunnel size based on the control MRI scan, and the spatial determination of BB in relation to the bone tunnel location were evaluated. To analyze the relationship between BBs and BTE in homogeneous groups regarding the time from injury to ACLR (t(I-S)), the largest subgroup B (n = 15), in which t(I-S) was 31 to 60 days, was isolated for further investigation. Results: Based on subgroup B, a weak correlation (r = 0.33) existed between the BB volume and BTE size in the femur and tibia. Considering the relationship between the distance from the BB to the bone tunnel in the femur (f-l) and its enlargement (Δfd), there was a moderate and statistically significant (p < 0.05) negative correlation (r = −0.64). The correlation between those parameters was even stronger (r = −0.77) in subgroup B (time interval between injury and surgery ranged from 31 to 60 days). Conclusions: A retrospective analysis of MRI data in patients after ACL reconstruction surgery showed a relevant association between the distance from the BB to the bone tunnel and BTE in the femur. The relationship was not confirmed in the tibia.

Bone Bruises of the Ankle and Mid-foot Often Associate with Ankle Sprain

Background: Ankle sprains are one of the most common musculoskeletal injuries. However, they may be more serious than commonly believed since many patients reportedly experience chronic problems afterwards. It is necessary to improve the treatment, such as the method and duration of fixation, of sprained ankles.Methods: Magnetic resonance imaging of 70 patients with acute moderate or advanced ankle sprains presenting consecutively between November 2014 and December 2019 were reviewed for analysis of bone bruising associated with ankle sprains. The patients were treated conservatively with a solid splint or cast until walking pain could be resolved without external fixation. In cases with pain at the time of weight bearing after solid fixation, crutches were prescribed for pain relief. The fixation period ranged from 8 days to 72 days (mean: 29.5 days). Afterwards, 54.0% of patients had walking pain and required the use of crutches. The ankle joint pain disappeared after conservative treatment in all patients.Results: The incidence of bone bruises detected by magnetic resonance imaging in the ankle and midfoot associated with ankle sprain was 81.4%. Bone bruises of the midfoot, including the tarsal bone and Chopart joint, were found in 34.3% of ankle sprains. Bone bruises of the talus were the most common, being present in 60% of ankle sprains. Bone bruises were also evident in the tibia (44.3%), the calcaneus (21.4%), and the tarsal bone (25.7%). There was a significant association between bone bruises of the talocrural joint surface and use of the crutches after fixation (P=0.041). Multiple regression analysis adjusted for age and gender revealed that bone bruises of the talocrural joint surface of the talus was a significant independent predictor of crutch use (P=0.045), with an odds ratio (95% confidence interval) of 3.03 (1.03-8.94).Conclusion: Bone bruises of the ankle and midfoot are often present in ankle sprains. In moderate or advanced cases of ankle sprain, external solid fixation of both the ankle and midfoot should be performed. In cases with pain at weight bearing following solid fixation, crutches are advised for pain relief and proper ligament and bone healing.

Bone Bruise Distribution Patterns After Acute Anterior Cruciate Ligament Ruptures: Implications for the Injury Mechanism

Background: Bone bruises observed on magnetic resonance imaging (MRI) after an anterior cruciate ligament (ACL) injury could provide significant information about ACL injury mechanisms. Purpose/Hypothesis: The purpose of this study was to investigate common bone bruise patterns after an ACL injury. It was hypothesized that the most common bone bruise distribution pattern would be only the lateral side of both the femur and tibia. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee MRI scans of patients who underwent acute ACL reconstruction from August 2016 to August 2018 at our institution were selected. Imaging sequences in the sagittal and coronal planes were used for determining the bone bruise location in the lateral-medial and anterior-posterior directions, respectively. The presence, location, and intensity of bone bruises within specific compartments of the tibia and femur were documented. The relative bone bruise patterns of the tibia and femur were classified and analyzed. Results: A total of 207 patients (165 men, 42 women) met the inclusion criteria from a total of 4209 ACL reconstruction cases. The most common relative bone bruise pattern was located on only the lateral side of both the femur and the tibia (44.4%), followed by the lateral and medial sides of both the femur and tibia (29.0%). For the pattern found on the lateral and medial sides of both the femur and tibia, the bone bruises on only the lateral side of both the tibia and femur were more severe ( P < .001 and P < .001, respectively) and more anterior ( P < .001 and P < .001, respectively) than those on only the medial side. Conclusion: The most common relative bone bruise pattern observed was on only the lateral side of both the tibia and femur. Bone bruises on the lateral side were more severe than those on the medial side in patients with bone bruises on the lateral and medial sides of both the femur and tibia. Anterior translation of the tibia relative to the femur occurred during an ACL injury based on the location of bone bruises in the anterior-posterior direction.

Bone Bruise and Anterior Cruciate Ligament Tears: Presence, Distribution Pattern, and Associated Lesions in the Pediatric Population

Background: Bone bruise characteristics after anterior cruciate ligament (ACL) injury have been correlated with the level of joint derangement in adults. However, the literature lacks information about younger patients, whose higher ligamentous laxity may lead to different lesion patterns. Purpose: To investigate the prevalence, size, location, and role of bone bruise associated with ACL rupture in the pediatric population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee magnetic resonance imaging scans (MRIs) of patients aged 8 to 16 years with ACL tears from 2010 to 2018 were selected from the institution database. Inclusion criteria were open or partially open physes, less than 90 days between trauma and MRI, and no history of injury or surgery. Presence, localization, and size of bone bruise were analyzed by 2 blinded researchers and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruise subscale. Ligamentous, cartilaginous, meniscal, and other lesions were documented. Results: Of the 78 pediatric patients selected from the database, 54 (69%) had bone bruise. The mean area of bone bruise was larger in males than in females (femur, 3.8 ± 2.8 vs 2.2 ± 1.4 cm2, respectively, P = .006; tibia, 2.6 ± 1.6 vs 1.5 ± 0.8 cm2, respectively, P = .007). The subregions most affected by bone bruise were the lateral posterior tibia and the lateral central femur (in 83% and 80% of the knees affected, respectively). A low correlation was found between age and bone bruise area (biggest areas r = 0.30, P = .03, and sum of areas r = 0.27, P = .04), but no correlation was found between age and WORMS (femur, r = −0.03, P = .85; tibia, r = −0.04, P = .76). The injuries most associated with bone bruise were 23 meniscal lesions (43%), 10 lesions of other ligaments (19.0%), 2 cartilage lesions (3.7%), and 2 patellar fractures (3.7%). Conclusion: The prevalence of bone bruises in pediatric patients with ACL tears is high, although it seems slightly lower than the prevalence documented in adults but with similar localization. The area and the distribution pattern of bone bruises are similar among different ages. The pediatric patients had a lower presence of cartilage and meniscal lesions compared with that reported in adults, which suggests a different effect of this trauma on the knee of pediatric patients.