Correlation of acromial morphology with impingement syndrome and rotator cuff tears

Figures & data

Figure 1. Overview of parameters of acromial morphology.

Table 1. Frequencies and (percentages)

	Sex		Bigliani shape
Group	Male	Female	I	II	III
1 (controls)	37 (74)	13 (26)	9 (18)	40 (80)	1 (2)
2 (impingement)	31 (62)	19 (38)	14 (28)	26 (52)	10 (20)
3 (cuff tears)	33 (66)	17 (34)	14 (28)	26 (52)	10 (20)

Table 2. Descriptive statistics

	Mean	Range	SD
Group 1 (controls)
Age, years	48	31–86	14
Acromial slope	21°	1–41°	8
Acromial tilt	29°	17–42°	5
Lateral acromial angle	84°	71–96°	6
Acromion index	0.67	0.5–0.84	0.1
Group 2 (impingement)
Age	49	31–77	9
Acromial slope	25°	1–42°	11
Acromial tilt	33°	22–41	5
Lateral acromial angle	83°	71–96	6
Acromion index	0.73	0.53–0.96	0.1
Group 3 (cuff tears)
Age	60	38–78	9
Acromial slope	25°	1–51°	12°
Acromial tilt	34°	18–58°	7°
Lateral acromial angle	77°	63–94°	8°
Acromion index	0.75	0.54–0.96	0.1

Figure 2. Box plots of significant differences in morphological parameters. Significant findings for acromial slope, lateral acromial angle, acromion index, and patient age. Group 1: controls; group 2: impingement; group 3: supraspinatus tendon tears.

Table 3. Correlations

	Age	Bigliani	Acromial slope	Acromial tilt	Lateral acromial angle	Acromion index
Age
PCC		< 0.001	–0.007	0.08	–0.33 ^a	0.22 ^a
p-value		1.0	0.9	0.3	< 0.001	0.01
Bigliani
PCC	< 0.001		0.74 ^a	–0.22 ^a	0.077	–0.078
p-value	1.0		< 0.001	0.01	0.4	0.3
Acromial slope
PCC	–0.007	0.74 ^a		–0.17 ^a	0.069	–0.056
p-value	0.9	< 0.001		0.04	0.4	0.5
Acromial tilt
PCC	0.08	–0.22 ^a	–0.17 ^b		–0.26 ^a	0.24 ^a
p-value	0.3	0.01	0.04		0.001	0.003
Lateral acromial angle
PCC	–0.33 ^a	0.077	0.07	–0.26 ^a		–0.49 ^a
p-value	< 0.001	0.4	0.4	0.001		< 0.001
Acromion index
PCC	0.22 ^a	–0.078	–0.056	0.24 ^a	–0.49 ^a
p-value	0.01	0.3	0.5	0.003	< 0.001

PCC: Pearson correlation coefficient, which was graded as excellent (0.81–1.00), good (0.61–0.80), moderate (0.41–0.60), fair (0.21–0.40), or poor (0.00–0.20).

^a Correlation is significant at the 1% level (2-tailed).

^b Correlation is significant at the 5% level (2-tailed).

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