New parameters describing morphological variations in the suprascapular notch region as potential predictors of suprascapular nerve entrapment

Table 1 Characteristics of ARC associated parameters according to STSL and SSN types

Parameters of area reduction		STSL		SSN type
Parameters of area reduction		Fan-type	Band-type	IA	IB	IC	II	IIIA	IIIB	IIIC	IV	V
Number		56	44	2	1	2	11	6	13	59	3	3
aSSN [mm²]	Mean	119.1	93.66	140.7	240	109.75	100.1	111.4	130.1	103.35	106.71	43.2
	SD	42.3	31.17	76.01	-	7.42	27.7	28.87	47.98	34.02	17.62	29
	p	0.0032		0.0556
aSTSL [mm²]	Mean	76.8	65.3	94.3	172	78.1	67.9	77.6	78.23	68.38	91.37	34.6
	SD	28.12	23	10.3	-	17.68	26.09	13.36	31.55	22.52	6.86	24.23
	p	0.05887		0.0261^†
aACSL [mm²]*	Mean	9.03	10.12	18.2	-	11.3	11.59	-	11.39	9.2	-	-
	SD	8.69	6.63	-	-	1.84	7.31	-	9.02	7.32	-	-
	p	0.1996		0.3423
aSSO [mm²]	Mean	38.56	23.9	41.95	64	21.85	26.89	32.17	47.21	31.1	13.17	9.1
	SD	22.32	16.33	59.3	-	9.4	14.5	18.97	28.67	17.96	8.58	6.99
	p	0.0004		0.1395
SN passage area [mm²]	Mean	36.84	20.86	36.5	64	7.8	22.78	32.17	43.8	29.5	13.17	7.8
	SD	21.89	15.46	51.2	-	3.96	13.22	18.97	30.6	17.2	8.58	5.35
	p	0.00017		0.0306^†
ARC_STSL [%]	Mean	65.3	70.9	76.1	71.7	70.8	67.3	71.6	61.1	67.2	86.5	74.2
	SD	10.7	13.8	33.8	-	11.3	13.4	12.8	11.3	11.5	8.3	1.1
	p	0.0274		0.1526
ARC_ACSL [%]*	Mean	7.9	10.2	9.4	-	10.3	12.6	-	10.5	8.5	-	-
	SD	8.2	7	-	-	1	8.5	-	8.3	7.3	-	-
	p	0.2947		0.0489^†
ARC [%]	Mean	68.6	77.6	80.8	71.7	81.0	78.1	71.6	67.6	70.8	86.5	86.6
	SD	10.5	12.5	27.2	-	12.3	14.3	12.8	11.3	10.8	8.3	11.2
	p	0.00002		0.0966