Inferior fixation with a new pin design for external fixation: A randomized study in 50 patients operated on by the hemicallotasis technique

Figures & data

Table 1.  Patient characteristics of the study group

	All n = 50	Xcaliber n = 25	Standard n = 25
Sex (n): men	37	19	18
women	13	6	7
Age, mean (SD)	51 (7.4)	52 (7.2)	52 (7.2)
BMI, mean (SD)	29 (3.3)	29 (3.2)	29 (3.5)
Medial arthrosis (n)	42	20	22
Lateral arthrosis (n)	8	5	3
HKA angle
Medial arthrosis (SD)		171 (5.9)	170(3.9)
Lateral arthrosis (SD)		187(5.9)	186(7.1)

BMI: body mass index;

HKA angle: hip-knee-ankle angle, <180 degrees = varus.

Table 2.  Mean (SD) insertion torque force (Nm) for both types of pins, for the 4 pin positions

	Standard pin	Xcaliber pin	P-value
Position	n = 25	n = 25
Proximal
medial	2.21 (0.85)	1.39 (0.82)^a	0.001
lateral	2.05 (0.97)	1.12 (0.78)^a	< 0.001
Diaphyseal
proximal	6.89 (1.40)	3.78(1.26)	< 0.001
distal	7.14(1.20)	3.40(1.60)^a	< 0.001

^aone pin excluded.

Table 3.  Mean (SD) extraction torque force (Nm) for both types of pins for the 4 pin positions

	Standard pin	Xcaliber pin	P-value
Position	n = 25	n = 25
Proximal
medial	4.22 (3.47)	1.69 (1.99) ^a	0.003
lateral	4.44 (2.79)	1.27 (1.42) ^a	<0.001
Diaphyseal
proximal	2.01 (2.05)	1.56(1.19)	0.4
distal	1.85(1.9)	1.28 (0.89) ^a	0.2

^a one pin excluded

Table 4.  Mean (SD) difference between insertion and extraction torque force (Nm) and mean pin performance index (PPI) for both types of pins, for the 4 pin positions

	Standard pin	Xcaliber pin		Standard pin	Xcaliber pin
	n = 25	n = 25		n = 25	n = 25
Position	Mean diff. (Nm)	Mean diff. (Nm)	P-value	PPI (%)	PPI (%)	95% CI
Proximal
medial	2.01 (3.32)	0.30 (1.99) ^a	0.04	208	170	-144–68
lateral	2.23(3.10)	0.21 (1.63)	0.007	285	173	-252–30
Diaphyseal
proximal	−4.92 (1.75)	−2.22 (1.48) ^a	< 0.001	24	41	4–31
distal	−5.31 (1.72)	−2.10 (1.58) ^a	< 0.001	27	45	1–36

^aone pin excluded.

95% CI: 95% confidence interval.