Anatomy and injuries of the pediatric wrist: beyond the basics

Paediatric fractures of carpal bones other than the scaphoid

OBJECTIVES

Fractures of carpal bones other than the scaphoid are rare in children. The aim of this study was to analyze results and identify risk factors for an unfavorable outcome.

MATERIAL AND METHODS

Children and adolescents up to the age of 16 years who sustained a carpal fracture other than in the scaphoid between 2004 and 2021 were reviewed in this single-center retrospective study.

RESULTS

In a series of 209 children and adolescents with carpal fractures, 22 had fractures other than the scaphoid. Mean age was 13 years (range 8-16) years, with a total of 41 fractures, with highest incidences for the capitate (10), trapezium (6), triquetrum (4) and pisiform (4). Twenty-nine of these 41 fractures were missed on initial X-ray. Non-displaced fractures were treated with a short arm spica cast including the thumb. Four patients were operated on for displacement fracture or carpometacarpal subluxation. All fractures united, and patients returned to full activities. At the final consultation at a median 14 months (range 6-89) post-injury, all patients with non-displaced fractures were free of symptoms, with excellent Mayo Wrist Scores (MWS). However, three patients with operated trapezium fractures developed early radiological signs of osteoarthritis, two of them with residual pain and MWS rated only good.

CONCLUSION

Non-displaced pediatric carpal fractures treated by forearm cast have excellent prognosis. Fractures of the trapezium with displacement or first carpometacarpal subluxation incur a risk of osteoarthritis despite anatomical reduction and internal fixation.

Radiographic Scapholunate Interval in the Pediatric Population Decreases in Size as Age Increases

BACKGROUND

Widening of the scapholunate (SL) interval greater than 2 mm is diagnostic of an injury in adults; however, this absolute number cannot be used for skeletally immature individuals due to the ossification of the carpal bones. The purpose of this study was to determine age-appropriate normative values for the radiographic SL interval in the skeletally immature population.

METHODS

Normal pediatric wrist radiographs were identified. The radiographic SL interval was measured as the distance between the scaphoid and the lunate at the mid-joint space between the scaphoid and the lunate, and the SL and capitolunate angles were measured on lateral views. An initial inter-rater reliability assessment was completed with strong inter-rater reliability.

RESULTS

In all, 529 radiographic series of children (276 male), aged 4 to 17 years, were reviewed. A negative linear correlation between chronological age and distance at the mid-joint space was observed. The average values for the radiographic SL interval ranged from 9.07 to 1.57 mm. The average SL and capitolunate angles were 52.0° and 10.6°, respectively. No linear relationship was found between chronological age and SL or capitolunate angle (R = 0.07 and 0.03, respectively).

CONCLUSIONS

The visible radiographic distance between the scaphoid and the lunate decreases with increasing age as the carpal bones ossify. The normative values defined in this study can be used to determine whether a true widening of the SL interval is present in the pediatric population. No linear relationship exists between chronological age and SL or capitolunate angle.

COMPUTED TOMOGRAPHY MEDICAL IMAGE ANALYSIS OF BASKETBALL PLAYERS’ BONE GEOMETRY

ABSTRACT Introduction: Basketball sports will effect on the morphology and structure of the hand bones and joints. Objective: The article selected nine professional basketball players (basketball group) and 11 non-basketball players (control group) in the provincial youth team. A 64-row spiral computed tomography scan was used to scan the wrist and three-dimensional reconstruction. The volume of each carpal bone and the computed tomography value (bone density) were measured. Methods: To explore the influence of basketball sports on the hand bones and joints’ morphological structure, the paper analyzes the structural characteristics of the computed tomography images of young male basketball players’ wrist bones. Results: Compared with the carpal bones in the control group, the volume of the right navicular bone and the small polygonal bone, the left-hand navicular bone, the large triangular bone, and the small polygonal bone in the basketball group increased significantly (P<0.05). Conclusions: Basketball can increase the volume of the part of the wrist bones of adolescent male athletes and reduce the bone density; the morphological structure of the non-smashing wrist bones of basketball players has similar changes to that of the spikers. Level of evidence II; Therapeutic studies - investigation of treatment results.

Uniquely pediatric upper extremity injuries

The pediatric population is prone to unique upper extremity injuries that are not typically seen in adults. The normal dynamic maturation pattern of ossification centers and open physis can potentially confuse radiologists who are not familiar with the pediatric patients. In this review article, we discuss the normal anatomy and commonly encountered acute and chronic upper extremity injuries such as supracondylar distal humeral fracture and osteochondritis dissecans, in pediatric patients. Diagnosing the correct type of fracture (e.g., buckle vs Salter-Harris) is important for proper management of the injury. With an increasing number of adolescents participating in competitive sports, specific sports related injuries such as little league shoulder, gymnast wrist, and medial epicondyle apophysitis, are also discussed in this review. We examine late complications of injuries, such as physeal bar formation and fishtail deformity of the distal humerus.