External fixators and lengthening systems in pediatric upper limb

Abstract

The use of external fixators is part of the cultural background of orthopedic surgeons in treating numerous clinical conditions. Over the years, fixator design and biomechanical knowledge have led to different solutions and techniques, and bone lengthening and its better understanding come together with the development of external fixators and the application of the biological principle of distraction osteogenesis. The authors conducted a literature review about using external fixators and lengthening systems in pediatric upper limbs. Despite the applications of external fixators in upper limbs remaining much more limited than those of the lower limbs, there are indications of traumatic, congenital, tumor, and infectious etiologies. However, despite the spread of new systems of plate and screws and intramedullary lengthening nails, the problems about when to use external fixation remain unsolved. Another debated point is about using monolateral or circular frames for humeral lengthening and the correction of forearm deformities in multiple hereditary exostoses disease (MHE) or radial longitudinal deficiency sequelae. Monoaxial fixators retain a prominent role for skeletal lengthening in all the districts examined, although their role could be outclassed by the motorized intramedullary nails, especially for humeral lengthening. Hexapod systems are likely to represent the future for the correction of multiplanar forearm deformities; however, multicenter studies on larger series will be necessary to better validate their applications and advantages.

Keywords: External fixator; pediatric deformities; upper limb.

Figure 1.

(A) Humeral shortening in achondroplasia. (B) Lengthening with an axial external fixator. (C and D) Final lengthening.

Figure 2.

(A) Ulnar shortening in MHE. (B–D) Correction with an axial external fixator and distraction osteogenesis. MHE: multiple hereditary exostoses.

Figure 3.

(A) Ulnar shortening in radial longitudinal deficiency. (B) Correction and elongation with the external axial fixator. (C) Final results after 3 cm of lengthening.

Figure 4.

(A) Ulnar shortening and deviation in radial longitudinal deficiency. (B and C) Correction of the wrist axis and elongation with hexapod frame. (D) Final correction.

Figure 5.

(A) Missed Monteggia 2 months after trauma. (B and C) Open radial head reduction and ulnar flexion osteotomy with an axial external fixator.