No effect of risedronate on femoral periprosthetic bone loss following total hip arthroplasty

Figures & data

Table 1. Baseline characteristics of the patients

	Placebo (n = 31)	Risedronate (n = 30)
Age, years^a	60 (5)	62 (5)
Male sex, n	18	20
BMI^a	27 (4)	28 (5)
ASA classification, n
1 or 2 / 3 or 4	30/1	29/1
Charnley class, n
A/B/C	17/11/2	15/12/4
EQ-5D preoperatively^a	0.35 (0.30)	0.43 (0.29)
HHS preoperatively^a	46 (14)	45 (14)
Bone mineral density, total hip
WHO classification, n
normal/osteopenia/osteoporosis	26/3/2	22/8/0
Density (g/cm^2)^a	1.06 (0.20)	1.01 (0.17)
Bone mineral density, lumbar spine
WHO classification, n
normal/osteopenia/osteoporosis	23/6/2	24/5/1
Density (g/cm^2)^a	1.30 (0.30)	1.24 (0.21)
Stem size, n
8–10/11–13/14–15 mm	7/21/3	12/14/4

^a mean (SD).

WHO: World Health Organization BMD classification;

ASA: American Society of Anaesthesiologists;

EQ-5D: EuroQol 5 dimensions; HHS: Harris hip score.

Table 2. The effect of risedronate on primary and secondary endpoints at 4 years. A Bonferroni correction has been applied to all p-values

Outcome	Placebo (n = 31)	Risedronate (n = 30)	Difference (95% CI)	p-value
Primary endpoint, change in BMD (%)^a
zone 1	−21 (13)	−19 (14)	−1.8 (−8.6 to 4.9)	1.0
zone 7	−22 (15)	−23 (16)	0.5 (−7.5 to 8.4)	1.0
Secondary endpoints, change in BMD (%)^a
zone 2	−2.5 (7.8)	−0.6 (7.9)	−1.9 (−10.3 to 6.4)	1.0
zone 3	−3.4 (7.8)	1.7 (10.6)	−5.1 (−9.9 to 5.9)	0.3
zone 4	−3.3 (9.3)	−1.7 (6.0)	−1.6 (−5.6 to 2.4)	1.0
zone 5	−2.8 (7.0)	2.8 (6.4)	0.0 (−3.4 to 3.4)	1.0
zone 6	−6.2 (11.9)	3.9 (10.4)	−2.3 (−8.1 to 3.4)	1.0
zones 1–7	−6.8 (6.5)	−4.3 (4.8)	−2.5 (−5.4 to 0.5)	0.8
BMD L1–L4, g/cm^2	1.3 (0.24)	1.3 (0.27)
Other endpoints
Vertical migration of the stem, mm^a	−1.7 (1.5)	−1.7 (1.2)
Harris hip score^a	94 (7)	94 (10)
EuroQoL^a	0.9 (0.2)	0.8 (0.2)
Heterotopic ossification, n
none	23	20
Class I–II	7	8
Class III–IV	1	2
Adverse events, n
hip dislocation	1	0
cardiovascular events	3	2
malignancy	1	2
respiratory events	2	1
other	6	4

^a mean (SD); p-value from unpaired Student’s t-test.