Growth modulation with a medial malleolar screw for ankle valgus deformity

Figures & data

Figure 1. Follow-up.

Table 1. Group assignment

Etiology of ankle valgus (Group)	No. of patients (ankles)	Age at op., years (range)	Age at removal, years (range)	Time to removal, months (range)
Clubfoot (CF)	21 (29)	11.0 (8.7–14.0)	12.0 (9.7–15.3)	15 (6–39)
Hereditary multiple exostoses (HME)	15 (27)	11.7 (9.6–14.7)	13.4 (10.9–16.7)	22 (12–46)
Idiopathic (IP)	12 (21)	12.1 (8.7–16.5)	14.4 (10.2–19.0)	17 (6–35)
Cerebral palsy (CP)	8 (14)	12.3 (10.3–15.3)	14.2 (11.3–16.6)	14 (11–17)
Meningomyelocele (MMC)	7 (13)	11.1 (9.9–14.2)	13.1 (11.4–15.1)	24 (18–30)
Fibular hypoplasia (FH)	7 (7)	11.6 (7.9–12.9)	14.2 (12.7–15.6)	20 (9–33)
Other^a	9 (14)	12.2 (7.4–14.1)	13.8 (10.2–14.9)	15 (6–34)
Total	79 (125)	11.7 (7.4–16.5)	13.3 (9.7–19.0)	18 (6–46)

^a In the “other” group, 3 patients had Down’s syndrome, 2 had scleroderma, and 1 had mucopolysaccharidosis. In 2 other children, the valgus deformity occurred after trauma, and in 1 child as a result of osteomyelitis.

Figure 2. Lateral distal tibial angle (LDTA). This is determined by measuring the angle created by the intersection of the central axis of the tibia and a second line drawn across the epiphyseal surface of the distal tibia.

Table 2. Results of radiographic analyses

Group	LDTA (°)		Angular correcction, °/month (range)
	Preop. (range)	At removal (range)
CF	81 (75–84)	90 (88–94)	0.78 (0.21–2.17)
HME	77 (68–84)^a	89 (76–97)	0.60 (0.11–1.33)
IDP	82 (76–85)	89 (83–91)	0.56 (0.10–1.57)
CP	82 (74–85)	90 (87–92)	0.54 (0.17–1.16)
MMC	77 (70–85)	87 (73–91)	0.38 (0.10–0.72)
FH	80 (67–84)	90 (89–90)	0.55 (0.30–0.78)
Other	81 (70–85)	90 (89–90)	0.76 (0.25–1.67)
Total	80 (67-85)	89 (73-97)	0.65 (0.1–2.2)

For abbreviations, see Table 1.

^a HME patients had a lower preoperative LDTA than IDP patients (p = 0.004) and CF patients (p = 0.003).

Figure 3. Case series. Full correction within 26 months in a boy with a meningomyelocele. The deformity was balanced at the time of physeal closure

Table 3. Literature review

Authors	No. of patients (ankles)	Main associated diagnosis	Age at op. years	Years of follow-up	Correction, mean (°)	Correction, °/month
Stevens and Belle 1997	31 (50)	Neuromuscular	11.8	4	10	0.19
Davids et al. 1997	17 (29)	CF / HME	11.2	2	12	0.59
Rupprecht et al. 2011	9 (11)	HME	11.2	3	14	0.58
Stevens et al. 2011	33 (57)	CF	10.4	2	11	0.60
Driscoll et al. 2013	41 (58)	HME (19)	10.3	2	9	0.37
		Non-HME (22)				0.51

For abbreviations, see Table 1.

Stevens P M, Belle R M. Screw epiphysiodesis for ankle valgus. J Pediatr Orthop 1997;17:9-12.

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Davids J R, Valadie A L, Ferguson R L, et al. Surgical management of ankle valgus in children: use of a transphyseal medial malleolar screw. J Pediatr Orthop 1997; 17: 3-8

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Rupprecht M, Spiro A S, Rueger J M, Stücker R. Temporary screw epiphyseodesis of the distal tibia: a therapeutic option for ankle valgus in patients with hereditary multiple exostosis. J Pediatr Orthop 2011; 31(1): 89-94.

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Stevens P M, Kennedy J M, Hung M. Guided growth for ankle valgus. J Pediatr Orthop 2011; 31(8): 878-83.

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Driscoll M, Linton J, Sullivan E, Scott A. Correction and recurrence of ankle valgus in skeletally immature patients with multiple hereditary exostoses. Foot Ankle Int 2013; 34(9): 1267-73.

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