Limb lengthening and peripheral nerve function—factors associated with deterioration of conduction

Figures & data

Table 1. Conduction velocity in m/s by etiology

	Congenital	Etiology Growth disturbance	Trauma
Mean (SD) age, years	14 (6.8)	13 (3.1)	27. (9.6)
Mean (SD) length gained, cm	6.5 (3.0)	9.5 (4.2)	5.4 (0.9)
Median (IQR) conduction
velocities:
Preoperatively	50 (7.5)	46 (15)	43 (18)
Postoperatively	49 (8.0)	50 (5.3)	23 (42)
After lengthening	46 (11)	48 (6.1)	26 (53)

Table 2. Latencies of F-waves in milliseconds by etiology ^a

	Congenital	Etiology Growth disturbance	Trauma
Preoperatively	40 (5.1)	42 (5.9)	51 (9.1)
Postoperatively	41 (14)	39 (15)	50 (15)
After lengthening	45 (9.9)	46 (23)	51 (6.3)

^a Median (IQR).

Figure 1. Mean (95% CI) change in conduction velocity between preoperatively and postoperatively.

Table 3. Patients with and without a 12% drop (considered to be a clinically relevant change) in nerve function for different etiologies. A significantly greater risk of nerve dysfunction was observed in patients with a congenital etiology (chi-square, p = 0.03)

	Yes	No	Total
Congenital	7	10	17
Growth disturbance	0	6	6
Total	7	16	23

Figure 2. Length gained and change in conduction velocity after lengthening. Large changes in conduction velocity (in 2 trauma cases and 1 congenital case) are indicative of poor outcome, as these reflect poor postoperative conduction. There was no association between these cases and amount of lengthening.

Figure 3. Change in conduction velocity according to nerve assessed.