Posterior Root Avulsion Fracture of the Medial Meniscus in a Skeletally Immature Child: A Case Report.

CASE: We describe a rare case of posterior root avulsion fracture of the medial meniscus in an 11-year-old boy. Previous reports have demonstrated delayed diagnosis, but in this case, multiplanar computed tomography (CT) combined with magnetic resonance imaging (MRI) enabled early diagnosis and treatment. Gradual ossification was observed after arthroscopic suture fixation, and meniscal extrusion did not progress. He returned to sports without any symptoms and showed no degenerative changes at 2.5 years postoperatively. CONCLUSION: This is the first case report of early diagnosis and time-course analysis of a rare avulsion fracture, emphasizing the usefulness of CT combined with MRI.

Classifying Ischial Tuberosity Avulsion Fractures by Ossification Stage and Tendon Attachment.

BACKGROUND: We propose a new classification system for ischial tuberosity fractures in adolescents that is based on the ossification pattern of the apophysis. METHODS: We performed a retrospective review of patients who were diagnosed with ischial tuberosity avulsion fractures at a single institution from 2008 to 2018. Skeletal maturity and fracture location, size, and displacement were recorded based on initial injury radiographs. The fractures were classified by location as being lateral (type 1) or complete (type 2). Pelvic computed tomography (CT) review demonstrated 5 stages of ossification. We then reviewed pelvic CT and magnetic resonance imaging scans to assess the tendinous insertions at the ischial tuberosity apophysis. Reliability analysis was performed. RESULTS: We identified 45 ischial tuberosity fractures. The mean patient age was 14.4 years (range, 10.3 to 18.0 years). Boys accounted for 82% of the cohort. Forty-seven percent of the fractures were classified as type 1, and 53% were classified as type 2. Type-1 fractures were associated with younger age (p = 0.001), lower Risser score (p = 0.002), lower modified Oxford score (p = 0.002), less displacement (p = 0.001), and smaller size (p < 0.001) when compared with type-2 fractures. Of the 45 patients, 18 had follow-up of >6 months, with 56% going on to nonunion. Nonunion was associated with greater displacement (p = 0.016) and size (p = 0.027). When comparing union rates by fracture type, 33% of type-1 fractures progressed to nonunion, while 78% percent of type-2 fractures progressed to nonunion; however, this difference was not significant (p = 0.153). A review of the advanced imaging indicated that type-1 fractures involved the semimembranosus and conjoined tendons, whereas type-2 fractures also involved the adductor magnus tendon. CONCLUSIONS: We propose a new classification system based on the ossification pattern of the ischial tuberosity apophysis that reflects the skeletal maturity of the patient, the size and location of the fracture, and the amount of displacement, and likely predicts the probability of subsequent nonunion. The ischial tuberosity ossifies in a pattern similar to the iliac crest as described by Risser, and this pattern of ossification dictates the size of the ischial tuberosity avulsion fracture fragments and the involved tendons.

The amount of displacement can determine non-operative treatment in posterior cruciate ligament avulsion fracture.

PURPOSE: It is generally agreed that surgical treatment is warranted for acute posterior cruciate ligament (PCL) avulsion fracture with displacement. However, the amount of displacement that warrants surgical treatment has not been defined. The purpose of this study was to determine the optimal cut-off value for displacement of posterior cruciate ligament avulsion fracture in determining non-operative treatment and to compare the results of non-operative treatment in acute isolated PCL avulsion fractures with non-operative treatment of acute PCL injury. METHODS: Between 2007 and 2017, 30 consecutive patients with acute isolated PCL avulsion fractures and 70 consecutive patients with acute isolated PCL injuries, all of whom underwent non-operative treatment (cast immobilization with > 2 years of follow-up) were retrospectively analyzed. Clinical scores including the International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity score, as well as side-to-side differences on stress radiographs, were compared between the PCL avulsion fracture and PCL injury groups at the final follow-up. The failure rates of non-operative treatment were also compared. The predictive value of the amount of fracture displacement for successful non-operative treatment was calculated using area under the receiver operating characteristic curve (AUROC). The optimal cut-off of the amount of fracture displacement to determine non-operative treatment was based on the maximal sum of sensitivity and specificity. RESULTS: The two groups exhibited comparable clinical scores and mean side-to-side differences on stress radiographs. There were 5 (16.6%) failures of non-operative treatment in the PCL avulsion fracture group and 19 (27.1%) failures in the PCL injury group. (n.s) There was a significant positive correlation between the amount of initial avulsion fracture displacement and side-to-side difference in posterior stress radiographs at final follow up (P < 0.001). The optimal cut-off value for the amount of fracture displacement in PCL avulsion fracture to predict failure of non-operative treatment was 6.7 mm (AUROC = 1.0). CONCLUSION: The outcomes of non-operative treatment of acute isolated PCL avulsion fractures were comparable to those of patients with acute isolated PCL injuries. Acute PCL avulsion injuries with displacement of less than 6.7 mm should be considered for non-operative treatment. LEVEL OF EVIDENCE: IV.

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.

Avulsion fracture of the medial head of the gastrocnemius muscle associated with multiple ligament injuries before closure of the growth plate: a case report.

BACKGROUND: Avulsion fracture of the medial head of the gastrocnemius muscle is a very rare phenomenon. There are no reports of avulsion fractures associated with multiple ligament injuries before closure of the growth plate. The authors present a case of avulsion fracture of the insertion of the medial head of the gastrocnemius muscle associated with posterior cruciate ligament injury and an avulsion fracture of the medial collateral ligament at the femoral attachment. CASE PRESENTATION: A 15-year-old Japanese boy was injured by contact with another player while playing soccer. He was immediately admitted to the authors' hospital with knee pain. Radiography and computed tomography revealed an avulsion fracture of the medial collateral ligament at the femoral attachment and an avulsion fracture of the medial head of the gastrocnemius muscle. In examination under anesthesia, the Lachman test was negative and posterior drawer test was positive. Fixation of the avulsion fractures of the medial collateral ligament and medial head of the gastrocnemius was performed 9 days after the injury. After fixation, valgus instability at full extension had disappeared. The knee was immobilized in a brace for 2 weeks postoperatively. One year postoperatively, the posterior drawer test was slightly positive; however, our patient was able to ambulate without pain and returned to sports without feeling instability in his knee. CONCLUSION: A rare case of avulsion fracture of the gastrocnemius muscle combined with multiple ligament injuries before closure of the growth plate is described. A satisfactory result was obtained by fixation of the avulsed bone fragments of the gastrocnemius muscle and medial collateral ligament. The authors believe that avulsion fracture of the medial head of the gastrocnemius muscle associated with posterior cruciate ligament injury should be repaired.

Patella incarceration with associated patella fracture: a rare case of a paediatric patient with no associated femoral fracture.

We describe the case of a 15-year-old girl who presented to the Accident and Emergency Department with right knee pain and a tense effusion following a twist and fall directly onto her right knee. An MRI scan demonstrated that she had an incarcerated dislocated patella with an associated patella avulsion fracture. This required open reduction. Open reduction and fixation was performed using suture anchors. We feel that this case is particularly pertinent since nearly all previous case reports describe an incarcerated patella with an associated femur fracture. Furthermore, no previous case reports have been published in a child.

Iliac crest apophyseal insufficiency avulsion fractures.

Iliac crest apophyseal avulsion fractures are rare injuries caused mainly through forceful contraction of attached muscles during high level sporting activities. We present the first case of a spontaneous iliac crest apophyseal avulsion insufficiency fracture in a patient with severe atopic eczema on oral steroids and review the relevant literature.

Anterior Inferior Iliac Spine Deformity as a Cause for Extra-articular Hip Impingement in Young Athletes After an Avulsion Fracture: A Case Report.

Extra-articular hip impingement from prior traumatic injury to the anterior inferior iliac spine (AIIS) is an uncommon cause of groin pain in young athletes. Currently, the most common treatment for this injury is arthroscopic decompression. However, hip arthroscopy is not universally available and requires advanced skills. We report 2 cases of the development of extra-articular hip impingement from unusual bony exostoses off the AIIS after traumatic injury in 2 young athletes who underwent open surgical resection. The multidisciplinary sports medicine team should be aware of the development of extra-articular impingement from traumatic injury to the AIIS and that open surgical resection is a viable alternative to arthroscopic decompression.

An Unusual Case of an Intra-Articular Osseous Fragment Associated with a Medial Collateral Ligament Femoral Avulsion Fracture in an Adult: A Case Report.

CASE: The medial collateral ligament (MCL) is the most commonly injured ligament of the knee; however, to our knowledge, avulsion fractures of the MCL resulting in an intra-articular fragment have not been reported. We present the case of a 55-year-old woman with a posterior cruciate ligament avulsion fracture and an MCL avulsion fracture with an intra-articular bony fragment. CONCLUSION: Patients who sustain trauma to the knee should be carefully evaluated for ligamentous avulsion injuries. Avulsion fractures in adults represent substantial traumatic injuries, and associated injuries should be suspected. While the MCL is an extracapsular structure, this case report demonstrates that the MCL femoral-sided osseous attachment can displace intra-articularly.

Leptin is essential for microglial activation and neuropathic pain after preganglionic cervical root avulsion.

AIMS: Preganglionic cervical root avulsion (PCRA) affects both the peripheral and central nervous systems and is often associated with neuropathic pain. Unlike peripheral nerve injuries (PNI), central lesions caused by disruption of cervical roots from the spinal cord following PCRA contribute to the generation of neuropathic pain. Leptin is involved in the development of neuropathic pain after PNI by affecting neurons. However, whether leptin is involved in microglial activation leading to neuropathic pain after PCRA is unknown. MAIN METHODS: Preganglionic avulsion of the left 6th-8th cervical roots was performed in C57B/6J mice and leptin-deficient mice. A leptin antagonist or leptin was administered to C57B/6J mice and leptin-deficient mice after injury, respectively. The expression pattern of spinal and supraspinal microglia was examined by immunofluorescent staining. Von Frey filaments were used to test pain sensitivity. KEY FINDINGS: Leptin is essential for the development of neuropathic pain after PCRA. Allodynia was absent in the leptin-deficient mice and the mice administered the leptin antagonist. We also found that leptin deficiency or the administration of its antagonist inhibited the development of microgliosis in the dorsal horn and brainstem. Furthermore, increase in the expression of CD86 and iNOS, and Wallerian degeneration were noted in the spinal cord. The administration of exogenous leptin to leptin-deficient mice reversed these effects. SIGNIFICANCE: We concluded that leptin is involved in the proliferation and activation of microglia, which in turn enhances the development of neuropathic pain. Blocking the effects of leptin might be a target for the treatment of neuropathic pain after PCRA.

Apophyseal injuries in children's and youth sports.

INTRODUCTION: The authors reviewed the current English literature regarding apophyseal injuries affecting young athletes, to highlight the frequency and characteristics of these injuries, to clarify risk factors and specific prevention measures, and to identify future research objectives. SOURCES OF DATA: The authors performed a comprehensive search of the medical literature, using the Medline database, including all English articles. Various combinations of the Keywords 'injury', 'sports', 'athletic injuries', 'avulsion fractures', 'physeal', 'physis', 'apophysis', 'apophysitis', 'growth plate' were used. AREAS OF AGREEMENT: Growth benefits from a moderate physical activity. AREAS OF CONTROVERSY: Growth deficit may occur in young athletes involved in intensive practice of sport following apophysitis. GROWING POINTS: Apophyseal injuries occurring during sport are less common than overall rate of injuries affecting the adolescent population. Growth disturbance occurs only rarely after an apophyseal injury. AREAS TIMELY FOR DEVELOPING RESEARCH: Further studies should consider analytical as well as descriptive components of apophyseal injuries, to allow the identification of new possible risk factors and preventive measures and to help early detection and proper treatment as well.