Patient-reported outcome and muscle–tendon pain after periacetabular osteotomy are related: 1-year follow-up in 82 patients with hip dysplasia

Figures & data

Flowchart of the study process. 100 consecutive patients with symptomatic hip dysplasia scheduled for periacetabular osteotomy (PAO) were included from Department of Orthopedic Surgery, Aarhus University Hospital, Denmark.

Table 1. Characteristics of 82 consecutive patients with hip dysplasia

Patient characteristics	Before PAO	1 year after PAO
Age, years ^a	30 (9)	31 (9)
BMI ^a	23 (3)	24 (3)
Men, n	11	–
Duration of pain, years ^b	3 (1–6)	–
Bilateral hip dysplasia, n	74	–
CE angle (°) ^a	17 (5)	30 (5)
AI angle (°) ^a	14 (5)	3 (4)
Tönnis’s osteoarthritis grade 1, n	3	5
Positive FADIR test, n	70	55
Positive FABER test, n	62	47
Positive internal snapping hip test, n	25	16

Characteristics are presented as numbers or

^amean values (standard deviation),

^bmedian values (interquartile range)

Abbreviations: CE = centre-edge, AI = Tönnis’s acetabular index, FADIR = Flexion/Adduction/Internal Rotation,

FABER = Flexion/Abduction/External Rotation.

Table 2. Patient-reported outcome of PAO in 82 patients with hip dysplasia

Outcome score	Before PAO mean (SD)	1 year after PAO mean (SD)	Difference mean (CI)	Effect size Cohen’s d	p-value
HAGOS
Pain	50 (17)	76 (17)	26 (22–30)	1.37	< 0.001
Symptoms	48 (17)	67 (19)	19 (15–23)	0.99	< 0.001
ADL	55 (22)	81 (18)	27 (22–31)	1.25	< 0.001
Sport/recreation	39 (21)	64 (23)	25 (20–31)	1.02	< 0.001
PA	23 (24)	44 (33)	21 (14–28)	0.66	< 0.001
Quality of life	29 (14)	57 (25)	28 (22–33)	1.11	< 0.001
NRS Pain (IQR)	3 (2–5)	0 (0–2)		0.74	< 0.001

Abbreviations: HAGOS = Copenhagen Hip and Groin Outcome Score (0–100 points),

ADL = physical function in daily living, PA = preferred physical activity participation, NRS = numeric rating scale, IQR = interquartile range. 

Table 3. Muscle–tendon pain in 82 patients with hip dysplasia

Clinical entities	Before PAO	1 year after PAO % (CI)	Difference % (CI)	Effect size % points (CI) Cohen’s w	p-value
Iliopsoas-related pain	54 (42–65)	22 (14–32)	–32 (–46 to –17)	–1.96	< 0.001
Abductor-related pain	37 (26–48)	15 (8–24)	–22 (–36 to –8)	–1.12	0.002
Adductor-related pain	12 (6–21)	7 (3–15)	–5 (–16 to 6)	–0.11	0.5
Hamstrings-related pain	6 (2–14)	1 (0–7)	–5 (–12 to 2)	–0.29	0.2
Rectus-abdominis-related pain	4 (0–10)	0 (0–0)	–4 (–9 to 2)	–0.33	0.3
Patients with minimum 1
positive clinical entity	74 (64–83)	35 (25 to 47)	–39 (–54 to –24)	–2.46	< 0.001

Table 4. Associations between change in HAGOS (0–100 points) and change in muscle–tendon pain (n = 82)

	Crude		Adjusted ^a
HAGOS	β coefficient (CI)	p-value	β coefficient (CI)	p-value
Pain	–4.7 (–8.5 to –0.9)	0.02	–4.7 (–8.4 to –1.0)	0.01
Symptoms	–4.8 (–8.6 to –1.0)	0.02	–4.7 (–8.6 to –0.9)	0.02
ADL	–6.1 (–10 to –1.9)	0.005	–6.2 (–10 to –2.1)	0.004
Sport/recreation	–5.9 (–11 to –1.0)	0.02	–6.0 (–11 to –0.9)	0.02
PA	–1.2 (–7.9 to 5.5)	0.7	–1.2 (–7.9 to 5.6)	0.7
Quality of life	–8.2 (–13 to –3.3)	0.001	–8.2 (–13 to –3.3)	0.001

^aAdjusted for CE angles measured before and 1 year after PAO, age, and sex. Abbreviations: See Table 2