Avulsion fractures and chronic avulsion injuries of the knee: role of MR imaging

Avulsion fractures and chronic avulsion injuries of the knee are common lesions in sports-related trauma, especially among adolescents. Magnetic resonance imaging may prove useful in detecting and characterizing such lesions, and has several advantages with regard to other imaging modalities. We review, illustrate, and discuss the MR imaging features of some of the more frequent avulsion fractures and chronic avulsion injuries of the knee, including avulsion fractures of the cruciate ligaments, avulsion fractures of lateral and medial stabilizers, avulsion fractures and chronic avulsion injuries of the extensor mechanism, and avulsive cortical irregularities of the distal femur. The role of MR imaging in evaluating such lesions is emphasized.     

Treatment for ischial tuberosity avulsion fractures in adolescent athletes

Purpose

Avulsion fractures of the ischial tuberosity are rare sports injuries typically occurring in young athletes. Their misdiagnosis may lead to chronic pain or disability. The aim of this study is to report a retrospective series of patients sustaining a fracture of the ischial tuberosity and to propose decision guidelines.

Methods

The mechanism of accident, the diagnostic management, the mode of treatment and outcome after avulsion fractures of the ischial tuberosity in adolescents were analysed.

Results

Thirteen patients (1 female and 12 males) with a median age of 15 years (range 13–16 years) with an avulsion fracture of the ischial tuberosity were included. Twelve of these patients suffered from sports injuries leading to the avulsion fracture. Five of our patients with a displacement of >15 mm were treated operatively. The outcome was excellent in cases of acute presentation and osteosynthesis. Eight patients were treated conservatively: four of them showed a displacement of <15 mm and had an excellent outcome; and the other four patients had a displacement of >15 mm. Two of those patients had excellent outcome with regular bone healing, the remaining two patients developed pseudarthrosis associated with a good outcome.

Conclusion

The present paper shows that in patients with displacement of <15 mm, conservative treatment yields excellent results and early operative intervention should be considered in physically active patients with displacement of >15 mm.

Level of evidence

IV.     

Clinical outcome of arthroscopic reduction and suture for displaced acute and chronic tibial spine fractures

This paper reports the clinical outcome of the arthroscopic reduction and pull-out suture technique in acute and chronic displaced tibial spine anterior cruciate ligament (ACL) avulsion fractures. Between April 1997 and December 2000, 14 patients received an arthroscopic reduction and pull-out suturing of displaced tibial spine fractures (ACL avulsion fractures of tibia). Of 14 cases, ten were acute fractures and four were chronic nonunion fractures, in which all patients showed extension limitation. The mean follow-up period was 51 months (ranging from 30 to 80 months). At final follow-up, review of range of motion, Lachman test, anterior drawer test, KT-2000 arthrometer, Lysholm knee score, and Hospital for Special Surgery (HSS) score were evaluated. Compared to conventional pull-out suturing, several key modifications to surgical techniques were used. In all 14 patients, radiological bony union was detected at mean 12.3 weeks (range, 8–16 weeks) after surgery. All patients were able to return to their preinjury activity and sports level. At final follow-up, full range of motion was achieved in all patients. Anterior draw test, Lachman test, and KT-2000 (less than 3 mm side-to-side) were all negative in 13 patients. One female patient, who was 6 years old at the time of surgery, complained of no subjective instability, but showed Lachman grade I, and 5 mm side-to-side difference in KT-2000. She also revealed 10°̇ difference of genu recurvatum deformity. Two children (including the previously-mentioned 6-year-old female patient) showed leg-length discrepancy of 1 cm—the affected legs being longer—at final follow-up. The mean Lysholm knee scores were 95.6 (range, 92–100) and HSS knee scores were 96.4 (range, 91–100). Arthroscopic reduction with modified pull-out suturing technique in displaced tibial spine ACL avulsion fractures showed excellent union rate for both acute and chronic cases, without instability or extension limitations at minimum two-year follow-up.     

Avulsion fracture of the ulnar sublime tubercle in overhead throwing athletes

BACKGROUND: Injuries to the ulnar collateral ligament are relatively common in throwing athletes and result from either acute traumatic or repeated valgus stress to the elbow. Avulsion fracture of the sublime tubercle of the ulna is a rarely reported site of ulnar collateral ligament injury. PURPOSE: We retrospectively reviewed our cases of ulnar collateral ligament injuries to study avulsion fractures of the sublime tubercle of the ulna. STUDY DESIGN: Case series. METHODS: Data, including radiographs and magnetic resonance imaging scans, were obtained by review of hospital and office records and by follow-up examination. Of 33 consecutive patients treated for ulnar collateral ligament injuries, 8 had avulsion fractures of the sublime tubercle of the ulna. All eight were male baseball players with dominant arm involvement, an average age of 16.9 years, and an average follow-up of 23.6 months. RESULTS: Six of eight patients had failure of nonoperative treatment and required surgical repair. Two of the six underwent ulnar collateral ligament reconstruction and four had direct repair of the sublime tubercle avulsion with bioabsorbable suture anchors. At last follow-up, all eight had returned to their preinjury level of activity. No patient had residual medial elbow pain or laxity. CONCLUSIONS: Diagnosis of sublime tubercle avulsion fracture is made with history, physical examination, and radiographic studies. Magnetic resonance imaging can help identify an avulsion fracture not visible radiographically and can help determine whether direct repair or reconstruction is needed.     

Sports-related epiphyseal injuries of the lower extremity. An epidemiologic study.

Sports-related epiphyseal injuries in children and adolescents have been becoming more prevalent during recent years. We report 85 patients with epiphyseal fractures of the lower extremity treated in our hospital during the last twenty years, of which 60 were males and 25 females with an average age of 12.6 years (range 4 to 17 years of age). The injuries were sustained during soccer in 28% and during alpine skiing in 26% of the cases, of which the former was responsible for most of the injuries reported in males and the latter for those in females. The most frequently seen localizations were in the distal tibial epiphysis (31 cases), followed by the distal fibula (17) and the proximal tibial epiphysis (15). Of the reported 85 epiphyseal fractures 30 were Salter-Harris type I injuries, 25 type II, 8 type III and 11 were type IV fractures, while 11 were avulsion fractures. Of these patients, 56% were treated surgically, while conservative treatment was chosen for 44% of the patients. Of the 49 patients available for follow-up, complications were documented in 9 instances, including 3 leg length discrepancies, 4 axis deviations, one avascular necrosis of the femoral head and one case of osteomyelitis, of which 6 required corrective surgery.     

The unreamed intramedullary tibial nail in tibial shaft fractures of soccer players: a prospective study

Lower leg fractures are common and complex injuries in soccer players. Twenty-five mainly recreational soccer players who sustained a tibial shaft fracture were treated with the AO-UTN (Unreamed Tibial Nail). This prospective series included 25 males with a mean age of 28.1 years. These patients were prospectively followed for a mean period of 4.7 years. Clinical and radiographic data was collected. In addition, 20 patients completed an outcomes based questionnaire. In all but one case, the mechanism of injury was a contact with an opposing player. Shin guards provided little prevention against these fractures. The majority of these tibial shaft fractures were consistent with a short oblique or transverse fracture pattern. All fractures were stabilized with the UTN on the day of injury. Four patients had concurrent compartment syndromes and underwent a fasciotomy. Average time until bony consolidation was 11.3 weeks. No patients returned to competitive soccer activities earlier than five months after the initial injury (average 9.5). Only 11 out of 20 soccer players returned to the same level of sporting activity. Six patients never returned to playing soccer again after this injury, even without complications. The fracture of the tibial shaft in soccer players is a severe injury that can be treated safely with the UTN without major complications, but nevertheless only 50% of a mainly-recreational playing population return to the same competitive level as before the injury.     

Avulsion fractures of the pelvis

Avulsion fractures of the pelvic apophyses are seen infrequently but they show a consistent pattern in mechanism, patient's age, symptoms, physical findings, and roentgenographic appearance. Some disagreement exists in the literature concerning the treatment of these fractures. This study indicates that early diagnosis and a carefully directed nonoperative treatment program will produce positive results for avulsion fractures of the pelvis. Twenty-seven cases of acute avulsion fracture of the pelvis were successfully treated in a directed nonoperative program.     

Acute tibial tubercleavulsion fractures

Acute tibial tubercle avulsion fractures are commonly seen in athletes involved with jumping sports, especially basketball. These injuries typically occur in well-muscled, mature-appearing boys, 15 to 16 years of age, who generate high tensile forces at the tubercle junction. Possible associated injuries include patellar and quadriceps tendon avulsions, as well as collateral and cruciate ligament and meniscal damage. Treatment is based on the magnitude of injury. Recovery is rapid and the outcome is usually excellent, even in type III injuries.     

Avulsion fractures of both anterior and posterior cruciate ligament tibial insertions

Ipsilateral femur fracture, patellar fracture, and tibial avulsion fractures of anterior and posterior cruciate ligament injuries are reported. We know of no other report of an injury such as this in the literature. We sutured the tibial avulsion fractures by transtibial suturing technique and internally fixated the femur by intramedullary interlocking nailing 2 weeks after the trauma. After 1 year the results were evaluated as very good. Early surgical repair is valuable in these injuries.     

Magnetic resonance imaging findings of chronic lateral ankle instability

The ankle inversion injury is one of the most common types of injury that is encountered in athletes and active individuals. There are a wide variety of acute injuries associated with ankle inversion, including peroneal tendon tears, osteochondritis dessicans of the talus, anterior talofibular ligament avulsion, peroneal retinaculum avulsion, and calcaneofibular ligament tears. Chronic sequelae include impingement, posttraumatic degenerative arthritis, and an attenuated peroneal retinaculum. Most inversion injuries to the ankle have multiple associated injuries and isolated ligament injuries are uncommon. Chronically, the injured ankle usually demonstrates the injuries found at the time of the initial injury. Subsequently, there is a high frequency of these injuries in patients evaluated for symptoms of chronic lateral ankle instability. A high index of suspicion for the specific types of injuries associated with ankle inversions may result in a higher rate of injury detection and more expeditious and accurate diagnoses. Given the persistence of these injuries seen in patients with chronic posterolateral instability, injury patterns of ankle inversion are important to recognize even in the absence of acute trauma. We review the various types of injuries with their associated magnetic resonance (MR) imaging characteristics seen in patients with chronic lateral ankle instability.     

Avulsion fractures of the scapula

Fractures of the scapula due to direct violence are relatively common. Wilber and Evans [18] reported 40 scapular fractures and reviewed the literature. All those injured had received direct trauma to the shoulder and they were able to divide their cases into two groups, based on anatomical location and functional results. Scapular fractures due to avulsion of the muscular attachments are uncommon and, as reports of these injuries in the literature are usually confined to single cases, no classification has been established which takes account of the anatomical sites at which these fractures occur and the mechanism of injury involved.In this paper the more common sites of avulsion injury of the scapula are described and illustrated by case reports. In several of these the skeletal injury resulted from muscle contraction against a resisted force on the upper limb during the course of an accident. This mechanism has been implicated in fractures of the coracoid and acromion, but is shown in this paper to contribute to other avulsion fractures.     

MRI of anterior cruciate ligament injuries and associated findings in the pediatric knee: changes with skeletal maturation

OBJECTIVE: The objective of our study was to evaluate the MRI characteristics of anterior cruciate ligament (ACL) injuries and associated findings relative to skeletal maturity. We also contrast the frequency of findings in this younger population to adult data. MATERIALS AND METHODS: Eighty-two consecutive knees with an MRI report diagnosis of ACL injury (partial tear, sprain, or complete tear) or tibial spine avulsion fracture imaged over 4 years were retrospectively reviewed. Patients were grouped by degree of skeletal maturity as determined from the MR images. The examinations were reviewed for the type of ACL injury, secondary imaging findings, and associated knee injuries. Findings were correlated to skeletal maturity, and frequencies were compared with adult data. RESULTS: ACL injuries were more common in boys in the skeletally immature group, but more common in girls in the skeletally mature group (p = 0.03). Tibial spine avulsion fractures were most common in skeletally immature patients (p < 0.01), whereas complete tears of the ACL were most common in skeletally mature patients. Associated injuries were less common in the skeletally immature group, but this trend did not reach statistical significance. Most secondary signs of ACL injuries occurred at similar rates in all groups with frequencies similar to those reported in adults. CONCLUSION: ACL injuries in skeletally immature patients are seen more often in boys. Tibial avulsion fractures and partial tears are more common in younger, less rigid skeletons that may absorb the forces of trauma. As children mature, complete ACL tears and associated injuries occur in frequencies approaching those patterns seen in adults. Similarly, skeletally mature girls are affected more often than mature boys.     

Pediatric fractures during skateboarding, roller skating, and scooter riding

BACKGROUND: Skateboarding, roller skating, and scooter riding are popular recreational and sporting activities for children and adolescents but can be associated with skeletal injury. The purpose of this study is to describe the frequency and characteristics of fractures resulting from these activities. PURPOSE: Fractures from skateboarding, roller skating, and scooter riding compose a considerable proportion of pediatric musculoskeletal injuries. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Demographic data and injury characteristics were analyzed for all patients who presented to the pediatric fracture clinic of the level I trauma center from January 2001 to May 2002 after sustaining fractures due to skateboarding, roller skating, and scooter riding. RESULTS: Among a total of 2371 fractures, the authors identified 325 fractures (13.7%) that occurred during one of these activities. There were 187 patients (mean age, 13 years; 95% male) who sustained 191 skateboard-related fractures, 64 patients (mean age, 10.8 years; 54% male) who sustained 65 fractures while roller skating, and 66 patients (mean age, 9.7 years; 64% male) who sustained 69 fractures while riding a scooter. The forearm was fractured most often, composing 48.2% of skate-boarding fractures, 63.1% of roller-skating fractures, and 50.7% of fractures due to scooter riding. Of the forearm fractures, 94% were located in the distal third. In the skateboarding group, 10 of 191 (5.2%) fractures were open injuries of the forearm, compared to 6 of 2046 (0.3%) fractures caused by other mechanisms of injury (significant odds ratio, 18.8). CONCLUSIONS: Skateboarding, roller-skating, and scooter-riding accidents result in a large proportion of pediatric fractures. An open fracture, especially of the forearm, was more likely to be caused by skateboarding than by other mechanisms of injury. Use of wrist and forearm protective equipment should be considered in all children who ride a skateboard.     

Treatment of malunited fractures of the anterior tibial spine

Avulsion fractures of the anterior tibial spine are uncommon injuries, and most often seen in childhood. They can be associated with other intraarticular lesions and have, if adequately treated, a good long-term prognosis. In adults these fractures can be complicated by loss of knee extension because of the displacement of the bony fragment. This is most often as a result of non- or malunion of the displaced fragment. We review two cases of malunited fractures of the anterior tibial spine. Both patients reported persistent knee pain and loss of knee extension, and had had an anterior knee laxity for a long time. They had been treated extensively by physiotherapy. In one patient, arthroscopy in another hospital revealed no reasons for the clinical symptoms. More than twenty years after the initial trauma, both patients visited our hospital. A radiograph and a magnetic resonance imaging were respectively carried out both of which revealed a malunited avulsion fracture. According to the examinations, the patients were treated by open reduction and internal fixation, and in the follow up exploration both no longer had discomfort. Clinical and radiological features of this less common and rarely reported injury are discussed and the surgical treatment is demonstrated.     

颌面部骨折并颅颈交界区损伤的CT诊断

目的 探讨颌面部骨折合并颅颈交界区损伤的影像学特点及多层螺旋CT诊断。方法 收集10例颌面部外伤合并颅颈交界区损伤的螺旋CT重建扫描资料，比较常用影像学检查手段的诊断价值。结果 上、下颌骨双骨折并颧弓骨折者5例，下颌骨骨折5例。其中3例合并颞颌关节脱位，3例合并有轻、中度颅脑损伤。合并颅颈交界区损伤有：枕颈脱位2例，枕骨髁撕脱骨折2例，寰枢椎旋转性半脱位6例，结论 颌面部外伤骨折合并上颈椎损伤多为韧带型损伤，影像学特点为小片的撕脱性骨折及枕颈半脱位、寰枢椎旋转性半脱位；多层螺旋CT重建技术是诊断本病的最佳方式；提高对本病的警惕，重视颅颈交界区解剖标志间关系的画线测量是防止漏诊的关键。     

When Groin Pain Is More Than ‘Just a Strain’

Most groin pain results from brief musculotendinous injuries, but not all groin pain signifies simply a pulled muscle. The pain can stem from one or more musculoskeletal or nonmusculoskeletal origins, such as avulsion fracture, osteitis pubis, or hernia. While acute causes are often readily identified, chronic groin pain can present a diagnostic challenge. Paying close attention to the history can help identify acute causes such as strains and avulsion fractures; determining the location and nature of the pain can also help with diagnosis. Conservative treatment is often effective for treatment of acute injuries such as strains and avulsion fractures.     

肩胛颈骨折的分类和手术治疗

目的 探讨肩胛颈骨折的分类及手术治疗. 方法对2000年1月-2007年12月收治的18例肩胛颈骨折进行回顾分析.男12例,女6例;年龄17～62岁,平均41岁.全部行CT检查.根据Hardegger分型,解剖颈骨折10例,外科颈骨折8例;按照Miller分型,ⅡA5例,ⅡB6例,ⅡC6例,ⅡB+ⅡC1例.15例有合并损伤.手术入路为后外侧入路9例,改良Judet入路6例,前后联合入路3例,应用重建钢板和拉力螺钉固定骨折. 结果全部患者随访6～70个月,平均25.5个月.根据Constant-Murley评分评价疗效,平均73分(35～95,中位数75.5).并发复位不良2例,肩关节不稳定1例,创伤性关节炎3例. 结论肩胛颈骨折成角畸形孟极角<20°、骨折移位≥10 mm、合并浮肩损伤或肩关节上方悬吊复合体损伤时,应早期手术治疗.预后影响因素主要为合并损伤、复位质量、固定坚强程度、肩袖损伤及术后康复等.     

Radiologic and clinical spectrum of occipital condyle fractures: retrospective review of 107 consecutive fractures in 95 patients

OBJECTIVE: We proposed to characterize the radiologic spectrum of occipital condyle fractures in a large series of patients and to correlate fracture pathology with neurosurgical treatment and patient outcome. MATERIALS AND METHODS: We conducted a retrospective review of the findings on conventional radiography, CT, and MR imaging in 95 patients with 107 occipital condyle fractures. We described fracture patterns according to two previously published classification systems. Clinical findings, neurosurgical management, and patient outcome were obtained from the medical records. RESULTS: Inferomedial avulsions (Anderson and Montesano type III) were the most common type of occipital condyle fracture, constituting 80 (75%) of 107 overall fractures. Unilateral occipital condyle fractures were found in 73 (77%) of 95 patients, and 58 patients were treated nonoperatively; occipitocervical fusion was required in nine patients for complex C1-C2 injuries, and six patients died. Bilateral occipital condyle fractures or occipitoatlantoaxial joint injuries were seen in 22 (23%) of 95 patients. Occipitocervical fusion or halo traction for the craniocervical junction was required in 12 patients, all of whom had CT evidence of bilateral occipitoatlantoaxial joint disruption and six of whom showed normal craniocervical relationships on conventional radiographs. Six patients with nondisplaced fractures were treated nonoperatively, and four patients died. Thirty (32%) of 95 patients showed continued disability, whereas 55 (57.5%) of 95 patients had good outcomes at 1 month. Associated cervical spine injuries were present in 29 (31%) of 95 patients. CONCLUSION: Given their associated traumatic brain and cervical spine injuries, occipital condyle fractures are markers of high-energy traumas. That conventional radiographs alone may miss up to half of the patients with acute craniocervical instability has not been well established. Avulsion fracture type and fracture displacement are associated with both injury mechanism and the need for surgical stabilization. In this series, most unilateral occipital condyle fractures were treated nonoperatively, whereas bilateral occipitoatlantoaxial joint injuries with findings of instability usually required surgical stabilization.     

Fractures of the patella in children

Fractures of the patella are relatively rare injuries for children. Fourteen patients with patellar fractures were reviewed. There were 12 boys and two girls with the age ranging between 9 and 15 years and an average of 11.4 years. Sleeve fractures were the most common type of patellar fractures observed (eight cases), followed by transverse fractures (four cases) and comminuted fractures (two cases). All the fractures were treated with open reduction and followed up for 2 to 20 years. Overall results were good in 13 patients, and flexion limitation of the knee was seen in one. Fractures of the patella in children are characterised by sleeve fractures. The prognosis of the patients treated with open reduction is generally good.     

弹性髓内钉固定治疗儿童下肢长管状骨骨折

目的 探讨弹性髓内钉(titanium elastic nails,TENs)固定治疗儿童下肢长管状骨骨折的疗效. 方法 2004年6月-2010年10月在C形臂X线机监视下采用TENs治疗儿童下肢长管状骨骨折患者278例,其中男181例,女97例;年龄3～14岁,平均7.6岁.股骨骨折162例,其中35例采用切开复位内固定,其余均采用闭合复位.胫骨骨折116例,均采用闭合复位内固定,术后支具固定3～4周.平均住院7d.272例于术后半年内取出内固定,242例获得1年以上的随访,并继续观察肢体长度和患儿髋膝关节活动以及步态情况. 结果 所有患者随访6～66个月,平均33个月.骨折均愈合,无严重并发症发生.术后无一例出现感染、延迟愈合、骨折不愈合、TENs折断、骨骺损伤等并发症.有10例于术后3～4个月出现钉尾红肿而提前拔钉.19例出现双下肢＜1.0 cm不等长,无明显跛行,下肢各关节功能无异常.根据Flynn评价标准,优良率达到100％. 结论 TENs固定治疗儿童下肢长管状骨骨折具有稳定性好、愈合快、切口小、复位满意、不破坏骨膜、利于骨折愈合、住院时间短、并发症少等特点,是治疗儿童下肢长管状骨的理想方法之一.