Bone discrepancy as a powerful indicator for early surgery in obstetric brachial plexus palsy

Abstract

Objectives: One of the unfortunate sequelae in obstetric brachial plexus palsy (OBPP) is upper limb length discrepancy. However, the influence of primary nerve reconstruction remains undetermined. In this study, the resultant discrepancy in children with OBPP who underwent primary reconstruction was analyzed in relation to the severity of the lesion, the timing of surgery, and the functional outcome following surgery.

Methods: Fifty-four patients that met the inclusion criteria were included in this study. Preoperative and postoperative bilateral scanograms were obtained to document the effect of reinnervation on bone growth. The length of the humerus, ulna, third metacarpal, third proximal phalange, and total limb length were measured and the percentage between the affected and normal side were accessed. Correlations between all the measures of limb length and measures of active motion (i.e., three different classification systems) were performed.

Results: Spearman's rank correlation coefficients revealed significant correlations between limb length discrepancies and nearly all measures of active upper extremity movement. The timing of surgery and the severity of the lesion significantly influenced the resultant limb length discrepancy.

Conclusions: The prevention of a non-acceptable upper limb discrepancy is fundamental for both the patient and family. The extent of the resultant discrepancy appeared to be strongly related to the time between injury and surgery, degree of severity, and the outcome of surgery. Patients with better functional recoveries of the affected upper extremities showed smaller differences in limb length.

Keywords: Functional outcome; Limb length discrepancy; Obstetric brachial plexus palsy; Primary reconstruction.

Figure 1

The effect of the denervation time (DT) on the absolute difference of the total limb length (p = 0.0003).

Figure 2

The effect of the denervation time (DT) on the of the total limb length (%) (p < 0.0001).

Figure 3

A girl presented at 3 months of age with right obstetric brachial plexus palsy (a). Preoperatively, there was no bone discrepancy between the affected and normal side (b). She underwent early nerve reconstruction (DT = 3 months) and the intraoperative findings were as follows: C5, C6—rupture; C7—traction; C8, T1—spared. At 7 years of age, the limb length discrepancy was indistinguishable (c and e). The absolute difference in total limb length was 0.9 cm and the percentage was 99% (d and f).

Figure 4

A boy presented at 6 years of age with a diagnosis of right obstetric brachial plexus palsy (a). The preoperative lengths were for the humeral 95%, ulna 89%, third metacarpal 88%, third proximal phalange 91%, and total length 92%, respectively. The absolute difference in total length was 3.7 cm. He underwent nerve reconstruction at that time (DT = 73 months). The intraoperative findings were as follows: C5—rupture; C6—avulsion; C7, C8, T1—avulsion/rupture. However, the discrepancy was progressive and 2 years later the absolute difference in total length was 8.4 cm (b). The percentage was for the humerus 92%, ulna 72%, third metacarpal 90%, third proximal phalange 91%, and total length 84%, respectively (c and d).

Figure 5

A girl presented at 11 months of age with right obstetrical brachial plexus palsy (a). The preoperative lengths were for the humerus 96%, ulna 96%, third metacarpal 87%, third proximal phalange 89%, and total length 94%, respectively. The absolute difference in total length was 1.4 cm (b). She underwent primary reconstruction at that time and the intraoperative findings were as follows: C5—rupture; C6, C7, C8—avulsion; T1—avulsion/rupture. Seven years later, the limb length discrepancy was cosmetically noticeable and objectionable (c). The absolute difference in total length was 9.6 cm. The percentage was for the humerus 89%, ulna 78%, third metacarpal 76%, third proximal phalange 84%, and total length 83%, respectively (d and e).