근골격계 초음파 진단 탐구 시작!! 2025

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• Published: 01 February 2025

Ultrasound-guided vs. fluoroscopy-guided percutaneous leverage reduction for severely displaced radial neck fractures in children: a comparative analysis of clinical and radiological outcomes

• Xing Wu, 
• Jingdong Xia, 
• Xiongtao Li, 
• Xiaoliang Chen, 
• Si Wang & 
• Xiantao Shen 

BMC Musculoskeletal Disorders volume 26, Article number: 106 (2025) Cite this article

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Abstract

Background

Ultrasound (US) is a promising alternative to fluoroscopy (FL) for guiding percutaneous leverage reduction of displaced radial neck fractures in children. However, few studies have compared these modalities. This study aims to compare both the accuracy and efficacy of FL-guided versus US-guided percutaneous pinning in the treatment of radial neck fracture.

Methods

Seventy-three children with displaced radial neck fractures were consecutively enrolled and assigned to the US or FL group. In all the patients, fractures were reduced with the percutaneous pin leverage technique. The patients were divided into two groups: the FL-guided group and the US-guided group. Baseline information, radiographs, and clinical results according to the criteria suggested by Metaizeau and complications were analyzed. Final Metaizeau criteria were categorized into excellent, good, fair, and poor.

Results

The success rates for closed reduction were 100% for the US group and 91.2% for the FL group. The US group exhibited a significantly shorter operation time compared to the FL group (24.77 ± 8.00 min vs. 42.21 ± 15.18 min; P < 0.01). Additionally, the US group had a significantly lower number of FL images and radiation dose (3.59 ± 1.57 times, 9.56 ± 6.08 mGy) than the FL group (22.26 ± 8.07 times, 69.68 ± 34.70 mGy; P < 0.001). Reduction quality did not significantly differ between the groups according to the Metaizeau reduction classification (P = 0.130). According to the Metaizeau classification criteria, there was no significant difference between the two groups, including post-operative complications.

Conclusion

Ultrasound-guided techniques offer a viable alternative for the treatment of displaced radial neck fractures in paediatric patients by minimising radiation exposure, expediting operative time and facilitating reduction.

Level of evidence

배경

초음파(US)는

소아의 이탈된 요골 경부 골절에 대한 경피적 레버리지 감압술을 안내하는 데

플루오로스코피(FL)의 유망한 대안으로 제시되고 있습니다.

그러나 이 두 방법을 비교한 연구는 아직 많지 않습니다.

본 연구는

요골 경부 골절의 치료에서 FL 안내형과 US 안내형 경피적 핀 고정술의 정확성과 효능을

비교하는 것을 목적으로 합니다.

방법

이동성 있는 방사골 경부 골절을 가진

73명의 어린이가 연속적으로 등록되어

US 그룹 또는 FL 그룹으로 배정되었습니다.

displaced radial neck fractures

모든 환자에게 경피적 핀 레버리지 기술로 골절이 감압되었습니다. 환자들은 FL 유도 그룹과 US 유도 그룹으로 나누어졌습니다. 기저 정보, 방사선 사진, Metaizeau가 제안한 기준에 따른 임상 결과 및 합병증이 분석되었습니다. 최종 Metaizeau 기준은 우수, 양호, 보통, 불량으로 분류되었습니다.

결과

폐쇄적 감압 성공률은 초음파 그룹에서 100%, FL 그룹에서 91.2%였습니다. 초음파 그룹은 FL 그룹에 비해 수술 시간이 유의미하게 짧았습니다 (24.77 ± 8.00 분 vs. 42.21 ± 15.18 분; P < 0.01). 또한 US 그룹은 FL 그룹에 비해 FL 영상 수와 방사선 노출량이 유의미하게 낮았습니다(3.59 ± 1.57회, 9.56 ± 6.08 mGy vs. 22.26 ± 8.07회, 69.68 ± 34.70 mGy; P < 0.001). Metaizeau 감압 분류에 따라 감압 품질은 두 그룹 간 유의미한 차이를 보이지 않았습니다 (P = 0.130). Metaizeau 분류 기준에 따르면, 두 그룹 간 수술 후 합병증을 포함해 유의미한 차이는 없었습니다.

결론

초음파 유도 기술은

소아 환자의 이탈된 방사골 경부 골절 치료에

방사선 노출을 최소화하고

수술 시간을 단축하며 감압을 용이하게 함으로써 유망한 대안으로 제시됩니다.

Radial neck fractures account for 5–10% of all elbow injuries in children [1]. Various surgical techniques have been reported for the management of displaced and angulated radial neck fractures in children [2,3,4,5]. However, there is still controversy and challenges regarding the optimal treatment approach for these fractures. Nevertheless, the closed reduction technique is preferred over open reduction.

Currently, fluoroscopic (FL) guidance is predominantly used during percutaneous pin leverage reduction; however, ionizing radiation exposure and visualization of the ossifying radial head within the elbow joint may be challenging. Ultrasound (US) offers real-time guidance with no ionizing radiation exposure and is broadly available and more affordable. It has demonstrated sufficient reliability and accuracy in diagnosing pediatric elbow fractures [8,9,10]. While several studies have shown that US-guided reduction is effective and reliable in the treatment of pediatric fractures [11, 12], only a few studies have reported on the use of a US-guided percutaneous leverage technique specifically for radial neck fractures [13,14,15,16].

There is limited consensus on the optimal internal fixation method for closed reduction in paediatric orthopaedics, with the Métaizeau technique [6] and the percutaneous pin leverage technique [7]. Our preference is for the percutaneous pin leverage reduction technique in the treatment of displaced radial neck fractures. Yet, to our knowledge, no studies have directly compared the outcomes of US-guided versus FL-guided percutaneous leverage technique for the management of displaced radial neck fractures. Our study was designed to test the hypothesis that US guidance can effectively replace FL guidance in pediatric patients, thereby reducing radiation exposure and shortening operative time. The objective of this study was to compare the accuracy and efficacy of US-guided versus FL-guided percutaneous leverage technique in these cases.

방사골 경부 골절은

어린이의 팔꿈치 손상의 5–10%를 차지합니다 [1].

어린이의 방사골 경부 골절 중 변위 및 각도 변형이 있는 경우

다양한 수술적 치료법이 보고되었습니다 [2,3,4,5]. 그

러나 이러한 골절의 최적 치료 접근법에 대한 논란과 도전 과제가 여전히 존재합니다.

그럼에도 불구하고 폐쇄적 정복술이 개방적 정복술보다 선호됩니다.

현재 경피적 핀 레버리지 감압 시술 시 주로 플루오로스코피(FL) 안내가 사용되지만, 이온화 방사선 노출과 팔꿈치 관절 내 골화 중인 방사골 머리의 시각화가 어려울 수 있습니다. 초음파(US)는 이온화 방사선 노출 없이 실시간 안내를 제공하며, 널리 사용 가능하고 비용이 저렴합니다. 초음파는 소아 팔꿈치 골절 진단에 충분한 신뢰성과 정확성을 보여주었습니다 [8,9,10]. 여러 연구에서 초음파 유도 감압술이 소아 골절 치료에 효과적이고 신뢰할 수 있음을 보여주었으나 [11, 12], 방사골 경부 골절에 대한 초음파 유도 경피적 레버리지 기술의 사용을 보고한 연구는 극히 드뭅니다 [13,14,15,16].

소아 정형외과에서 폐쇄적 감압 시 최적의 내부 고정 방법에 대한 합의는 제한적이며, Métaizeau 기술[6]과 경피적 핀 레버리지 기술[7]이 제안되었습니다. 우리는 전위된 상완골 경부 골절 치료에 경피적 핀 레버리지 감압 기술을 선호합니다. 그러나 우리 지식 범위 내에서 US 유도형과 FL 유도형 경피적 레버리지 기술의 결과를 직접 비교한 연구는 없습니다. 본 연구는 US 안내가 소아 환자에서 FL 안내를 효과적으로 대체할 수 있으며, 방사선 노출을 줄이고 수술 시간을 단축할 수 있다는 가설을 검증하기 위해 설계되었습니다. 본 연구의 목적은 이러한 경우에서 US 유도형과 FL 유도형 경피적 레버리지 기술의 정확성과 효능을 비교하는 것입니다.

Materials and methods

This retrospective study was approved by our institution’s internal review board. Informed consent for participation in the study was obtained from all participants. Between 2016 and 2021, the medical records and radiographs of the 73 eligible children were analysed in our hospital. The inclusion criterion was a closed, displaced radial neck fracture with an angulation greater than 30° in children with open growth plates. Concomitant injuries were not excluded from the study population. The exclusion criteria consisted of previous elbow injuries and associated elbow fractures requiring open reduction, open fractures, and incomplete medical or radiographic records.

Radial neck fractures were classified according to the method described by the O’Brien classification. There were 48 (65.8%) type II fractures and 25 (34.2%) type III fractures. The patients’ ages ranged from 2.5 to 14.25 years, with an average age of 7 years and 9 months. Among the patients, the left side was affected in 46 patients, whereas the right side was affected in 27 patients. Additionally, concomitant injuries were observed in twenty-nine patients: two had a compound fracture involving both the olecranon and distal radius, whereas the remaining twenty-seven had an olecranon fracture alone. Among these cases, sixteen were managed conservatively, whereas eleven cases with displaced olecranon fractures along with two cases presenting a compound olecranon and distal radius fracture underwent surgical treatment via closed reduction percutaneous pinning.

재료 및 방법

이 회고적 연구는 우리 기관의 내부 심사 위원회에서 승인되었습니다. 연구 참여에 대한 동의서는 모든 참가자로부터 획득되었습니다. 2016년부터 2021년까지 우리 병원에서 73명의 대상 아동의 의료 기록 및 방사선 사진을 분석했습니다. 포함 기준은 성장판이 열린 소아에서 30° 이상의 각도를 가진 폐쇄성 이동성 방사골 경부 골절이었습니다. 동반 손상은 연구 대상에서 제외되지 않았습니다. 제외 기준은 이전 팔꿈치 손상, 개방적 감압이 필요한 동반 팔꿈치 골절, 개방성 골절, 불완전한 의료 또는 방사선 기록이었습니다.

방사골 경부 골절은 O’Brien 분류법에 따라 분류되었습니다. II형 골절이 48건(65.8%), III형 골절이 25건(34.2%)이었습니다. 환자의 연령은 2.5세에서 14.25세 사이였으며, 평균 연령은 7세 9개월이었습니다. 환자 중 46명은 좌측이 영향을 받았으며, 27명은 우측이 영향을 받았습니다. 또한 29명의 환자에서 동반 손상이 관찰되었습니다: 2명은 상완골과 원위 요골 모두에 복합 골절이 있었으며, 나머지 27명은 상완골 골절만 있었습니다. 이 중 16명은 보존적 치료를 받았으며, 상완골 골절이 이동된 11건과 상완골 및 원위 요골 복합 골절을 동반한 2건은 폐쇄적 감압 및 경피적 핀 고정술을 통해 수술적 치료를 받았습니다.

Surgical techniques

All cases received percutaneous pin leverage technique. According to the treatment of the different guidance technique, patients were divided two groups: FL-guided (34 cases) or US-guided (39 cases). If closed percutaneous leverage reduction is not achievable, an accessory open reduction might be necessary for satisfactory reduction.

Ultrasound-guided procedure

Patients were positioned supine with the elbow maintained in semiflexion and forearm pronation under general anaesthesia. A GE LOGIQ e ultrasound system (GE Healthcare, Milwaukee, WI, USA) equipped with a 7.0–12.5 MHz linear array transducer (GE Healthcare, Tokyo) was used. US-guided techniques are performed in all surgical procedures by surgeons who are specifically trained in musculoskeletal US. During the operation, the ultrasound probe is connected through a single sterile laparoscopic sheath. Ultrasonographic imaging of the radial neck in three standardized sectional planes—anterior, lateral, and dorsal—facilitated monitoring and documentation of angulation and reduction progress. First, the site that provides the maximum angular image of interspace structures under US guidance was visually identified. Once the acoustic window displaying the maximal angulation view of the fracture line was located at the center of the screen, the skin insertion site was marked at the radial neck. Subsequently, a 1.5 mm Kirschner wire (K-wire) (2.0 mm for older children) was inserted via an in-plane technique from the posterolateral elbow direction (Fig. 1a). The K-wire was advanced strictly obliquely parallel to the long axis of the transducer, and the US enabled real-time visualization of its entire hyperechoic path. The K-wire continued to advance until its tip was accurately reached, and the displaced radial head was reduced effectively by leveraging it at a precisely established fracture gap location during intraoperative procedures (Fig. 1b; Supplementary video 1). Intraoperatively, reducing displaced fractures can be combined with an attempt to apply pressure on the lateral side of the radial neck and varus stress with the elbow extended. Once reduction was confirmed through US, the K-wire was advanced to penetrate through the contralateral distal cortex to maintain the proper reduction status. Additionally, US examination verified whether the K-wire penetrated the contralateral cortex and assisted in determining the length of retreatment to the bone cortex as well as the depth of K-wire insertion (Fig. 2). If a 2.0 mm pin was used as a lever, a 1.5 mm K-wire was percutaneously inserted for in situ fixation after removing the first pin. If necessary, a second K-wire may be placed. In accordance with previous literature report [13, 14], the final assessment of the K-wire position and whether it penetrated the contralateral cortex was conducted via the FL.

수술 기술

모든 환자는 경피적 핀 레버리지 기술을 적용받았습니다. 치료에 사용된 안내 기술에 따라 환자는 두 그룹으로 나뉘었습니다: FL 안내 그룹(34건)과 초음파 안내 그룹(39건). 폐쇄적 경피적 레버리지 감압이 불가능한 경우, 만족스러운 감압을 위해 보조적 개방 감압이 필요할 수 있습니다.

초음파 유도 절차

환자는 전신 마취 하에 팔꿈치를 반굴곡 위치에 유지하고 전완을 회전시킨 상태로 앙와위 자세로 배치되었습니다.

GE LOGIQ e 초음파 시스템(GE Healthcare, Milwaukee, WI, USA)에 7.0–12.5 MHz 선형 배열 트랜스듀서(GE Healthcare, Tokyo)가 장착된 장치를 사용했습니다. 초음파 유도 기술은 근골격계 초음파에 특화된 훈련을 받은 외과의사에 의해 모든 수술 절차에서 수행되었습니다. 수술 중 초음파 프로브는 단일 무균 복강경 시트에 연결되었습니다. 방사골 경부의 세 가지 표준 단면 평면(전방, 측방, 후방)에서의 초음파 영상은 각도 및 감압 진행 상황을 모니터링하고 기록하는 데 도움을 주었습니다.

먼저 초음파 유도 하에서 간격 구조물의 최대 각도 영상을 제공하는 부위를 시각적으로 식별했습니다. 골절 선의 최대 각도 영상을 표시하는 음향 창이 화면 중앙에 위치하면 방사골 경부에 피부 삽입 부위를 표시했습니다. 이후 1.5mm 키르슈너 와이어(K-와이어)(소아의 경우 2.0mm)를 후측측면 팔꿈치 방향에서 평면 내 기술로 삽입했습니다(그림 1a). K-와이어는 트랜스듀서의 장축과 엄격히 경사 평행하게 진전되었으며, 초음파를 통해 전체 고반향 경로를 실시간으로 시각화할 수 있었습니다. K-와이어는 끝이 정확히 도달할 때까지 계속 진전되었으며, 수술 중 정확히 설정된 골절 간격 위치에서 이를 활용하여 이탈된 방사골 머리를 효과적으로 감압했습니다(그림 1b; 보충 동영상 1).

수술 중 이탈된 골절을 감압하는 과정은 팔꿈치를 펴고 방사골 경부 측에 압력을 가하며 바루스 스트레스를 적용하는 시도를 결합할 수 있습니다. 초음파를 통해 감압이 확인되면 K-와이어를 반대쪽 원위 골피질에 관통시켜 적절한 감압 상태를 유지합니다. 추가로 초음파 검사를 통해 K-와이어가 반대쪽 골피질을 관통했는지 확인하고, 재치료 시 골피질까지의 길이 및 K-와이어 삽입 깊이를 결정하는 데 도움을 줍니다(그림 2). 2.0 mm 핀을 레버로 사용한 경우, 첫 번째 핀을 제거한 후 1.5 mm K-와이어를 경피적으로 삽입하여 현장 고정했습니다. 필요 시 두 번째 K-와이어를 배치할 수 있습니다. 이전 문헌 보고[13, 14]에 따라 K-와이어의 위치와 반대측 골피막을 관통했는지 최종 평가를 FL을 통해 수행했습니다.

Fig. 1

Ultrasound-guided percutaneous leverage reduction. (a) Under ultrasound guidance, a K-wire was inserted and the ultrasound transducer was positioned longitudinally of the elbow joint. (b) Fracture reduction was achieved by leveraging the K-wire, and assessment of reduction was performed using ultrasound imaging

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Fig. 2

The radiographs and ultrasound of the 6-year-old girl classified O’Brien type III. (a) Pre-operative anteroposterior radiographs. The intraoperative ultrasonographic view displays a clear visualization of the maximum angular image of the radial head in (b). Ultrasound imaging demonstrates post-reduction eval‎uation of the radial neck from anterior (c), lateral (d), and anteroposterior perspectives under fluoroscopy (e). C, epithelium epiphysis of humerus; R, radius; Arrowhead, cartilage, and cortex of radius; curved arrow, the position of the radial neck fracture; asterisk, epiphyseal core of ossification of the radial head

6세 소녀의 엑스레이와 초음파 검사 결과 O’Brien 유형 III로 분류되었습니다. (a) 수술 전 전후방 엑스레이. 수술 중 초음파 영상은 (b)에서 방사골 머리의 최대 각도 이미지를 명확히 보여줍니다. 초음파 영상은 방사선 투시술 하에서 전방(c), 측방(d), 전후방 관점에서 방사골 경부의 감압 후 평가를 보여줍니다. C, 상완골의 상피성 성장판; R, 방사골; 화살표, 방사골의 연골 및 피질; 곡선 화살표, 방사골 경부 골절의 위치; 별표, 방사골 머리의 골화 중심부.

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Fluoroscopy-guided Procedure

Patients were prepared as specified above for the US procedure. Percutaneous pinning procedures were performed under FL guidance. After an acceptable reduction was achieved through percutaneous leverage manipulation, percutaneous pinning was conducted.

Postoperative management and eval‎uation

The postoperative protocol was similar in both groups. The K-wire was left protruding out of the skin and bent over to prevent migration. A long arm cast with the forearm in a neutral position was applied. The K-wire was removed 4 ~ 6 weeks after surgery.

Outcome measurements

The dose area product (DAP; mGy/cm2) for each examination was measured by an inbuilt DAP meter on the image intensifier device. Imaging was performed via fluoroscopy-image intensifiers (BV Endura; Philips, Veenpluis, The Netherlands). During image acquisition, the dose, brightness, and contrast were automatically optimized.

During the follow-up, the patient’s radiological and clinical parameters were eval‎uated. Postoperative radiological assessments were conducted in accordance with the Métaizeau reduction classification [1]. The outcomes were categorized as follows: Excellent for anatomic reduction; Good for reductions within < 20 degrees; Fair for reductions between 20～40 degrees; and Poor for reductions exceeding 40 degrees. Clinical eval‎uations at the final follow-up utilized the Métaizeau functional classification [1]. The eval‎uation criteria for the Métaizeau classification are: (1) Excellent: no loss of motion; (2) Good: ≤20° loss of motion in any direction; (3) Fair: 20～40° loss of motion in any direction; (4) Poor: >40° loss of motion in any direction.

Statistical analysis

The SPSS statistical package (SPSS 20.0 version; IBM Corp, Armonk, NY) was used for statistical analysis. The categorical data were analysed via the chi-square (χ2) test, and the continuous data were analysed via t tests. The data are displayed as the means ± SDs or n (%). P < 0.05 was considered significant.

수술 후 관리 및 평가

수술 후 프로토콜은 두 그룹에서 유사했습니다. K-와이어는 피부 밖으로 돌출되도록 남겨두고 이동을 방지하기 위해 구부려졌습니다. 팔꿈치 아래 팔을 중립 위치에 고정하는 장갑형 석고 깁스를 적용했습니다. K-와이어는 수술 후 4~6주 후에 제거되었습니다.

결과 측정

각 검사 시의 선량 면적 제품(DAP; mGy/cm²)은 영상 증강 장치에 내장된 DAP 측정기로 측정되었습니다. 영상은 플루오로스코피-영상 증강 장치(BV Endura; Philips, Veenpluis, 네덜란드)를 통해 수행되었습니다. 영상 획득 시 선량, 밝기, 대비는 자동으로 최적화되었습니다.

추적 관찰 기간 동안 환자의 방사선학적 및 임상적 파라미터가 평가되었습니다. 수술 후 방사선학적 평가은 Métaizeau 감압 분류법 [1]에 따라 수행되었습니다. 결과는 다음과 같이 분류되었습니다: 해부학적 감압이 우수한 경우 ‘우수’; 20도 미만의 감압은 ‘좋음’; 20～40도 사이의 감압은 ‘보통’; 40도를 초과하는 감압은 ‘불량’. 최종 추적 관찰 시 임상 평가는 Métaizeau 기능 분류[1]를 활용했습니다. Métaizeau 분류의 평가 기준은 다음과 같습니다: (1) 우수: 운동 범위 손실 없음; (2) 양호: 어느 방향으로든 20° 이하의 운동 범위 손실; (3) 보통: 어느 방향으로든 20～40°의 운동 범위 손실; (4) 불량: 어느 방향으로든 40° 초과 운동 범위 손실.

통계 분석

통계 분석에는 SPSS 통계 패키지(SPSS 20.0 버전; IBM Corp, Armonk, NY)가 사용되었습니다. 범주형 데이터는 카이제곱(χ²) 검정을 통해 분석되었으며, 연속형 데이터는 t 검정을 통해 분석되었습니다. 데이터는 평균 ± 표준편차(SD) 또는 n (%)로 표시되었습니다. P < 0.05는 유의미한 차이로 간주되었습니다.

Results

The demographic and clinical characteristics of the patients in the US and FL groups are shown in Table 1. In this study, 39 patients (7.4 ± 2.5 years old, 21 males, 18 females) in the US group and 34 patients (8.2 ± 2.3 years old, 20 males, 14 females) in the FL group were included (Figs. 3 and 4). The mean follow-up period was 2 years and 1 month (range, 1 y 6 mo to 3 y 4 mo). There was no significant difference between the two groups concerning the baseline characteristics or fracture parameters.

결과

미국 그룹과 플로리다 그룹 환자의 인구통계학적 및 임상적 특성은 표 1에 제시되어 있습니다. 본 연구에는 미국 그룹 39명(7.4 ± 2.5세, 남성 21명, 여성 18명)과 플로리다 그룹 34명(8.2 ± 2.3세, 남성 20명, 여성 14명)이 포함되었습니다(그림 3 및 4). 평균 추적 관찰 기간은 2년 1개월(범위, 1년 6개월부터 3년 4개월)이었습니다. 두 그룹 간 기저 특성이나 골절 파라미터에 있어 유의미한 차이는 없었습니다.

Fig. 3

The radiographs and ultrasound of the 12-year-old boy classified O’Brien type III. (a) Pre-operative anteroposterior radiographs. (b) The angular image of the radial head in ultrasonographic view. Post-reduction image of the radial neck in lateral (c), anterior (d). C, epithelium epiphysis of humerus; R, radius; Arrowhead, cartilage of the radial neck; arrow, the position of the radial neck fracture; asterisk, epiphyseal core of ossification of the radial head

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Fig. 4

Percutaneous pinning penetrated through to the opposite cortex under US guidance. (a) The US transducer was placed parallel to the direction of insertion for K-wire placement. (b) Subsequently, the K-wire was inserted through the contralateral distal cortex under the US guidance. Arrowhead indicates K-wire with tip penetrating contralateral cortex; R, radial head

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Table 1 Patients’ demographic characteristics

Full size table

Table 2 Comparison of postoperative data between the two groups

Full size table

Table 1 shows that the operative times as 24.8 ± 8.0 min (95% confidence interval [CI]: 22.2 to 27.4) for the ultrasound (US) group and 42.2 ± 15.2 min (95% CI: 37.5 to 48.1) for the fluoroscopy (FL) group (P < 0.01). The number of FL images was 3.6 ± 1.6 times (95% CI: 3.1 to 4.1) in the US group and 22.3 ± 8.1 times (95% CI: 19.5 to 25.1) in the FL group (P < 0.001). The radiation dose was 9.6 ± 6.1 mGy (95% CI: 7.6 to 11.5) in the US group and 69.7 ± 34.7 mGy (95% CI: 57.6 to 81.8) in the FL group (P < 0.001). Consequently, US guidance significantly reduced both operative time and radiation exposure.The success rates for reduction were 100% and 91.2% in the US group and FL group, respectively. US can detect all instances where the fixation pin penetrates the contralateral cortex.

The results of the radiographic and functional outcome eval‎uations are shown in Table 2. According to the Metaizeau reduction classification, the excellent rates in the US group and FL group were 89.7% (35/39) and 76.5% (26/34), respectively; there was no significant difference between the two groups (p = 0.130). No further redisplacement occurred during the final radiographic examination in any group. However, according to the Metaizeau clinical classification at the last follow-up, the excellent and good rates in the US and FL groups were 97.4% (38/39) and 88.2% (30/34), respectively; there was no significant difference between the two groups (p = 0.197).

One patient from the FL group who underwent open reduction experienced premature physeal closure, whereas no such occurrence was observed among patients from the US group. Radial head overgrowth was observed in eight patients in the FL group and seven patients in the US group. No secondary displacement or nerve injury was noted during the follow-up period. In the FL group, one patient exhibited both joint stiffness and heterotopic ossification. No radial head necrosis was detected.

Discussion

Our study supports the hypothesis that US-guided percutaneous pinning is an effective method for treating displaced radial neck fractures, with comparable clinical outcomes to those of FL-guided methods. However, US guidance offers several advantages, including real-time visualization of the reduction process, shorter surgical time, reduced radiation exposure, and enhanced convenience. While FL remains the standard method for percutaneous pinning, our findings suggest that US may be a viable alternative in children. Additionally, US can provide valuable supplementary information regarding treatment and enable the assessment of articular cartilage in the radial neck.

The standard method of percutaneous pinning is FL guided [17]. Accurate anatomical data assessment via radiographic imaging is particularly challenging in the nonossified head of the radius [13, 18]. The rate of open reduction for fractures can reach up to 33% [19]. Nonetheless, open reduction remains a valuable resource for achieving anatomic reduction. Our study reported a 91.2% success rate with FL. We observed a 100% success rate with US, which is comparable to outcomes reported in previous studies [13, 17]. Utilizing US to determine the appropriate angle can reduce the need for multiple fluoroscopic images to ascertain the trajectory view. Consequently, ultrasound is more beneficial in assisting fracture reduction. No statistically significant difference in functional outcomes was detected between the two techniques during follow-up. Gutierrez-de [19] described excellent and good rate of 92.6% in percutaneous surgery with FL guidance. Our findings align with those of recent publications [13], ratings ranging from 81.5–100% [13, 16]. Similarly, both US and FL achieved equivalent functional outcomes [16]. However, based on our results, it is reasonable to consider US-guided methods as an alternative to FL-guided percutaneous pinning in this patient population, given that US has a higher excellent and good rate (97.4%) compared to FL-guided methods (88.2%). Our study observed a 23.1% incidence of complications associated with fluoroscopy and 35.3% with ultrasound. Radial head overgrowth was the predominant complication, a finding consistent with reports in the literature that estimate its occurrence at 18–37% among patients [20]. No significant difference in complication rates was noted between the two groups in our study, which aligns with previous literature [16]. However, patients who developed complications in both groups did not exhibit a significant deterioration in functional outcomes.

In this study, the US group demonstrated a significantly shorter operating time than the FL group did (24.8 min vs. 42.2 min, p < 0.001). Our findings on operating time are consistent with those of previous studies, which report durations ranging from 25 to 65 min [16, 21, 22]. However, US guidance in fracture reduction may not offer additional advantages over other methods, potentially increasing surgical time. The current findings contradict this. Similarly, in Su’s study, compared to FL, the surgery time was significantly lower with US guidance [16]. The time used in US-guided reduction is not surprising, as the sonographic technique of the in-plane pin approach allows real-time monitoring and safe advancement of the pin to the target structure within seconds. This finding emphasizes a substantial distinction in comparison with FL-guided reduction. Moreover, repeated manipulation and leverage may cause additional injury to the radial neck as well as increased operation time. Furthermore, previous studies did not provide visibility of the depth of the pin position during US guidance [13]. However, contrary to previous findings, we also found that US could confirm‎ bicortical purchase of fixation when the long axis of the transducer was advanced strictly parallel to the pin, eliminating the need for fluoroscopic control and saving time. Physicians with specialized training in US can use it as a primary diagnostic tool for accurately diagnosing pediatric elbow fractures [10]. Therefore, US-guided techniques should be considered as the standard of care in surgery.

In the present study, the mean angulation postreduction in the US group was 1.1°; in the FL group, it was 3.6°. Our results were consistent with previously published studies reporting mean angulation after surgery ranging from 3.6° to 7.5° [3, 13, 23]. Additionally, according to the Metaizeau reduction classification, a higher incidence of excellent outcomes was observed in the US group. Compared with FL guidance, US-guided assessment allows for the eval‎uation of reduction quality in multiple dimensions and results in a minor residual tilt and improved reduction quality; however, there are no significant differences between the US and FL groups regarding reduction quality or its correlation with clinical or radiographic outcomes [4]. Nevertheless, we believe that US-guided techniques offer a useful resource for achieving anatomical reduction of radial head fractures, which is a relevant factor in functional outcomes [24].

Our study revealed that fewer FL images and lower radiation exposures were required for the US group than for the FL group. In children undergoing FL-guided percutaneous pinning, Martus et al. [25] reported low radiation doses in radiation-sensitive regions, which were below the thresholds associated with radiation-induced infertility, skin abnormalities, and cataracts. However, owing to potential cumulative effects, even if the possible thresholds are not reached, each radiation exposure may subsequently increase the risk of future cancer development [26]. The acquisition of multiple images leads to an increased amount of radiation exposure for both patients and operators. Therefore, establishing limits on radiation exposure when selecting surgical treatment methods is recommended [27, 28]. Consequently, minimizing radiation exposure remains desirable for patients with high tissue radiosensitivity, such as children [29]. Nevertheless, poor visualization of the radial head and neck may result in increased use of radiation during procedures involving young children. Thus, the principle of a dose being “as low as reasonably practicable” must be maintained [30]. The mean DAP exposure in our study was comparable to that reported in other studies that involved the use of US for the percutaneous pin leverage technique [13].

It is controversial whether repeating percutaneous leverage reduction attempts may increase iatrogenic trauma by damaging the blood supply of the radial head [31,32,33]. The incorporation of C-arm fluoroscopic imaging to visualize the trajectory of the pin has been operator dependent. However, US guidance provides accurate visual anatomical structures during pin insertion. In the present study, the manual reduction process was similar in both groups, but US guidance reduced injuries to adjacent structures. In addition, the US-guided insertion site could be carefully selected to avoid damage to the posterior interosseous nerve. We did not observe posterior interosseous nerve injury, and there was no radial head necrosis during the follow-up. We believe that such a rather desirable outcome can be attributed to a set of technical factors.

We acknowledge that this study has several limitations. First, the retrospective nature of the study may inherently limit the conclusions that can be drawn. Our findings suggest a potential clinical benefit of the US approach. However, the low statistical power warrants further investigation with larger, multicenter, prospective studies to validate these results and improve generalizability. Nevertheless, it is worth noting that the present study represents the largest investigation on this topic published to date. Consequently, we believe that the results presented here can be generalized to cases treated by other clinicians employing focused US guidance. Second, all percutaneous pinning procedures in our trial were performed by experienced experts proficient in US- and FL-guided techniques. Although US-guided percutaneous pinning is considered a skill-level intervention, it is important to consider the potential surgeon effect when these results are applied in generalizable practice settings, particularly for novice operators. Furthermore, although FL was ultimately used to confirm‎ pin placement in this study, which is consistent with previous reports in the literature [13, 16], our findings revealed that US can assess pin penetration through the contralateral cortex in accordance with intraoperative fluoroscopic data. Therefore, the ultrasound-guided procedure demonstrated efficacy and reliability in cases where additional FL confirmation of K-wire positioning was unnecessary. In recent years, fluoroscopy has not been deemed necessary.

Conclusions

In conclusion, US offers substantial benefits in the pediatric orthopedic management of displaced radial neck fractures, including more efficient reduction techniques, shorter operative times and decreased radiation exposure. Despite similar outcomes between US and FL, US can be viewed as a viable alternative to FL, due to their comparable efficacy in the guidance of percutaneous leverage reduction. However, further randomized controlled trials are warranted to confirm‎ long-term efficacy.

Data availability

The datasets used and analysed during the current study are available from the corresponding author on reasonable request.

Abbreviations

US:

Ultrasound

FL:

Fluoroscopy

K-wire:

Kirschner wire

DAP:

Dose area product

MRI:

Magnetic resonance imaging

References

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