The role of ultrasound as a problem-solving tool in the assessment of paediatric musculoskeletal injuries

[Short-term effectiveness of ultrasound-guided Kirschner wire provocation technique in treatment of Salter-Harris types and periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents]

Objective

To investigate the short-term effectiveness of ultrasound-guided closed reduction by Kirschner wire provocation technique in the treatment of Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents.

Methods

Between May 2019 and May 2022, 41 patients with Salter Harris types Ⅰ and Ⅱ distal tibial epiphyseal fractures were admitted, all of whom had periosteal entrapment on preoperative MRI, and 38 cases (92.7%) were confirmed to have periosteal entrapment by intraoperative ultrasound. There were 24 males and 14 females, the age ranged from 6.8 to 15.7 years, with an average of 10.7 years; and there were 20 cases of Salter Harris type Ⅰ and 18 cases of type Ⅱ. The time from injury to operation was 22-76 hours, with an average of 28.4 hours. The preoperative imaging examination showed excellent alignment in 4 cases, good in 20 cases, and poor in 14 cases. The ultrasound guided Kirschner wire provocation technique for closed reduction and percutaneous Kirschner wire internal fixation were performed. The operation time, intraoperative fluoroscopy frequency, fracture healing time, and complications were recorded. Anteroposterior and lateral X-ray films of the affected ankle joint were taken before operation, at 3 months after operation, and at last follow-up to observe the healing of the fracture, and anteroposterior X-ray films of the whole length of both lower limbs were taken to evaluate the alignment of the force lines of the affected limbs. The range of motion (ROM), visual analogue scale (VAS) score, and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used to evaluate ankle function. The mechanical lateral distal tibia angle (mLDTA) and the anatomic anterior distal tibia angle (aADTA) were measured.

Results

The operation time ranged from 17 to 52 minutes, with an average of 22.6 minutes, and the intraoperative fluoroscopy frequency ranged from 3 to 11 times, with an average of 4.2 times. X-ray examination during operation and at 2 days after operation showed that anatomical reduction was achieved. All patients were followed up 10-24 months, with an average of 16.4 months. All fractures healed in 6.1-7.2 weeks, with an average of 6.3 weeks; no fracture displacement occurred, and the patients recovered to their pre-injury level of motion at 6 months after operation. Needle tail irritation occurred in 2 cases at 4 weeks after operation, and they recovered after symptomatic treatment. During the follow-up, there was no serious complication such as incision deep infection, bone nonunion, delayed union, and malunion. At last follow-up, the patients' alignment were all excellent, and the difference was significant when compared with preoperative one ( Z=-7.471, P<0.001). The VAS score, AOFAS ankle-hindfoot score, dorsiflexion-plantar flexion ROM, varus-valgus ROM, mLDTA, and aADTA significantly improved at 3 months after operation and last follow-up when compared with preoperative ones ( P<0.05).

Conclusion

Ultrasound-guided closed reduction by Kirschner wire provocation technique for treating Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents is minimally invasive and safe.

Musculoskeletal Soft-tissue Masses

Evaluation of soft-tissue masses has become a common clinical practice indication for imaging with both ultrasound and MR imaging. We illustrate the ultrasonography and MR imaging appearances of soft-tissue masses based on the various categories, updates, and reclassifications of the 2020 World Health Organization classification.

Imaging of Pediatric Lower Limb Sports Injuries

The importance of physical activity during childhood and adolescence has come to light, with an increase in sports-related acute traumatic and overuse injuries as a major disadvantage. A solid understanding of the physiology of the growing skeleton, together with knowledge about age- and sex-related differences in the occurrence of acute traumatic and overuse injuries is necessary. Every musculoskeletal radiologist should also be familiar with the appearances of these injuries on different imaging modalities. This review focuses on all these aspects concerning acute traumatic and overuse injuries among children and adolescents.

Ultrasonography-guided closed reduction in the treatment of displaced transphyseal fracture of the distal humerus

Background

To evaluate the clinical and radiographic outcomes of ultrasonography-guided closed reduction in the treatment of displaced transphyseal fracture of the distal humerus (TFDH).

Methods

Twenty-seven patients with displaced TFDH were successfully treated by the ultrasonography-guided closed reduction during January 2012 to December 2016 and were retrospectively reviewed. After the mean follow-up of 34.88 months, the clinical and radiographic outcomes of patients were evaluated. The cubitus varus of the affected elbows was also assessed at the latest follow-up.

Results

The successful rate of ultrasonography-guided closed reduction in the treatment of displaced TFDH was 84% (27/32). The twenty-seven patients with successful reduction were included for the following analysis. There were 20 males and 7 females included in the study, and the mean age at treatment was 15.39 ± 3.10 months; seventeen fractures occurred in the right side elbow and ten in the left side. At the last follow-up, there were significant decreases in the elbow flexion (3°, P = 0.027) and range of motion (5°, P = 0.003) between the injured and uninjured elbow, respectively, whereas no difference in elbow extension was detected (P = 0.110). Flynn’s criteria assessment showed that all the patients achieved excellent or good outcomes both in the functional and cosmetic categories. The clinical and radiographic carrying angles at the last follow-up were 11.67 ± 3.11° and 10.46 ± 3.88°, respectively. And the incidence of cubitus varus after treatment was 7.4% at the last follow-up.

Conclusion

The ultrasonography-guided closed reduction in the treatment of displaced TFDH is an effective procedure; the adequate fracture reduction can be acquired with the advantages of real-time, non-radioactive, and simple utilization. With the percutaneous pining fixation, satisfactory clinical and radiographic outcomes can be achieved with a low incidence of postoperative cubitus varus.

Forensic age assessment of the knee: proposal of a new classification system using two-dimensional ultrasound volumes and comparison to MRI

Objectives

To assess epiphyseal growth plate closure of the knee for forensic age estimation using an ultrasound (US)-based method and to compare the findings with MRI.

Methods

Thirty-three healthy male individuals (age, 14.4–19.3 years) were prospectively evaluated for epiphyseal growth plate closure of the right knee by recordings of two-dimensional US volumes and a high-resolution T1-weighted MRI sequence. The degree of epiphyseal growth plate closure was rated independently by two readers for each method using a modality specific three-point scale that differentiates between an open physis (S1), a partially closed physis (S2), and a closed physis (S3).

Results

The inter-rater agreement was high for the US (Cohen’s kappa (CK): femur 95.2%, tibia 81.3%, fibula 86.3%) and the MRI method (CK: femur 70.2%, tibia 90.8%, fibula 79.8%). The degree of growth plate closure associated positively with advancing age. The US system showed a clearer separation of median ages with lower overlap than the MRI system. Open growth plates on minors (< S3 on femur and tibia) were identified by US with higher sensitivity (1.0 vs. 0.7) and slightly lower specificity (0.7 vs. 0.85) compared with MRI. The examination time was substantially shorter on US than on MRI (2.65 ± 0.91 min vs. 24.72 ± 2.72 min; p < 0.001).

Conclusions

The US method for evaluation of growth plate closure of the knee can reliably assign male individuals to different ossification stages and identifies minors with high accuracy. More studies with larger numbers are needed to further evaluate this method.

Key Points

• US is feasible to determine the degree of epiphyseal growth plate closure of the knee, shows a high degree of reliability, and is comparable to MRI.

• US of the knee can detect open growth plates on male minors with high accuracy.

• US of the knee may be used as a fast, non-invasive imaging tool for forensic age estimation to identify male minors.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07343-1) contains supplementary material, which is available to authorized users.