Predictive factors for residual equinovarus deformity following Ponseti treatment and percutaneous Achilles tenotomy for idiopathic clubfoot

Figures & data

Radiographic measurement of the lateral tibiocalcaneal angle in each group of patients. A. A lateral tibiocalcaneal angle of 82° before PAT in a 3-month-old infant. B. The same infant at 15 months of age; the lateral tibiocalcaneal angle was 67°. This child was assigned to group 1. C. A lateral tibiocalcaneal angle of 118° before percutaneous Achilles tenotomy in a 3-month-old infant. D. The same infant at 12 months of age; the lateral tibiocalcaneal angle was 96° before selective soft tissue release was performed to treat the residual equinovarus deformity. This child was assigned to group 2.

Table 1. Characteristics of the 10 clubfeet in 7 patients with residual clubfoot deformities

Case	Sex	Age at PAT, months	Side	Radiographic result, degrees						Further operations
				Before PAT			Before definite operation
				ATC	LTibC	LTC	ATC	LTibC	LTC
1	F	1.9	R	–3	123	7	26	111	13	SPLATT
2	M	1.9	L	6	126	–5	20	110	8	TPAL, TAL(V), AHAL
3	M	2.0	R	–7	115	10	19	106	27	TPAL, TAL(V), AHAL
4	M	3.4	R	9	96	13	21	92	23	TPAL, AHAL
5	F	2.9	R	10	109	7	26	100	15	TPAL, TAL(V), AHAL
6	F	2.9	L	10	112	14	27	109	9	TPAL, TAL(V), AHAL
7	F	2.2	R	8	97	2	15	93	14	TPAL, AHAL
8	F	2.2	L	11	118	1	20	87	11	TPAL, AHAL
9	M	2.6	R	18	86	45	28	82	37	TPAL, TAL(V), AHAL
10	M	2.6	L	12	92	55	27	90	37	TPAL, TAL(V), AHAL

ATC: anterior talocalcaneal angle;

LTibC: lateral tibiocalcaneal angle;

LTC: lateral talocalcaneal angle;

PAT: percutaneous Achilles tenotomy;

AHAL: abductor hallucis aponeurotic lengthening;

TPAL: tibialis posterior aponeurotic lengthening;

TAL(V): vulpius-type tendon Achilles lengthening;

SPLATT: split anterior tibialis tendon transfer.

Table 2. Demographics of groups 1 and 2. Values are mean (SD)

	Group 1	Group 2	p-value ^a
	(n = 28)	(n = 7)
Age in days at the time of PAT	72 (19)	72 (17)	0.7
Weight in kg at the time of PAT	5.9 (1.0)	5.9 (1.0)	0.9
Duration of follow-up, months	24 (13)	19 (17)	0.009

^a Kruskal-Wallis

Table 3. Clinical scores of groups 1 and 2. Values are least-squares mean (SE) [95% CI]

	Group 1	Group 2	p-value ^a
	(n = 40)	(n = 10)
Dimeglio score, points	13 (0.6) [12–14]	13 (1.2) [11–16]	0.9
Initial Pirani score, points	4.3 (0.1) [4.0–4.6]	4.5 (0.3) [4.0–5.0]	0.5
Pirani score, points
at the time of PAT	2.2 (0.1) [2.0–2.4]	3.1 (0.2) [2.7–3.6]	< 0.001
at last follow-up examination	1.5 (0.1) [1.3–1.7]	2.7 (0.2) [2.2–3.2]	< 0.001

^a linear mixed model

Table 4. Radiographic data for groups 1 and 2 at the time of PAT. Values are least-squares means (SE) [95% CI]

	Group 1	Group 2	p-value ^a
Angle, degrees	(n = 40)	(n = 10)
Anterior talocalcaneal	8.1 (0.9) [6.2–10]	6.5 (1.9) [2.7–10]	0.4
Lateral tibiocalcaneal	95 (2.4) [90–100]	107 (4.7) [98–117]	0.03
Lateral talocalcaneal	28 (2.8) [23–34]	13 (5.6) [1.4–24]	0.02

^a linear mixed model

Table 5. Degree of correlation between Pirani score at the last follow-up examination and the radiographic parameters measured at the time of PAT. All values are correlation coefficient (p-value)

At last follow-up examination	ATC angle	LTibC angle	LTC angle
Pirani score	–0.021 (0.9)	0.61 (0.001) ^a	–0.42 (0.002) ^a
Degree of ADF	–0.20 (0.2)	–0.46 (0.001) ^a	0.23 (0.1)

^a Measured just before PAT.

For abbreviations, see Table 1

Table 6. Radiographic results of the 50 clubfeet that were evaluated by 2 observers at the time of PAT

	ATC	LTibC	LTC
	angle	angle	angle
Mean angle (SD) measured
by observer 1, degrees	8.3 (5.5)	98 (14)	26 (16)
by observer 2, degrees	7.6 (5.4)	97 (15)	25 (16)
Correlation coefficient	0.90	0.98	0.99
95% CI	0.83–0.94	0.90–0.97	0.98–1.0

SD: standard deviation.

For abbreviations, see Table 1