Table 12.

CSA & fat content of lumbar muscles at disc level of lumbar spine initially and on follow-up according to their type of management (n=51)

Level	Mean CSA (cm2) of lumbar muscles		Initial			3 mo			6 mo
			Operative (n=35)	Conservative (n=16)	p-valuea)	Operative (n=35)	Conservative (n=16)	p-valuea)	Operative (n=35)	Conservative (n=16)	p-valuea)
L1–L2	Multifidus	Left	4.55±0.44	4.54±0.47	0.972	4.08±0.27	4.06±0.29	0.860	4.39±0.48	4.31±0.60	0.605
		Right	4.38±0.48	4.21±0.22	0.100	3.96±0.41	3.74±0.31	0.055	4.15±0.59	3.84±0.37	0.066
	Erector spinae	Left	9.72±0.52	9.90±0.80	0.349	9.26±0.63	9.27±1.06	0.980	9.44±0.40	9.28±0.64	0.285
		Right	9.65±0.55	9.78±0.49	0.433	9.15±0.67	9.51±0.33	0.013	9.51±0.51	9.97±1.12	0.133
	Ilio-psoas	Left	6.62±0.41	6.71±0.33	0.482	6.73±1.09	6.66±0.43	0.717	6.55±0.30	6.61±0.48	0.562
		Right	6.55±0.39	6.53±0.33	0.855	6.14±0.37	6.09±0.40	0.646	6.21±0.52	6.16±0.41	0.738
	Quadratus lumborum	Left	4.89±0.27	5.00±0.32	0.204	4.66±0.44	4.79±0.49	0.333	4.65±0.41	4.76±0.37	0.360
		Right	4.74±0.36	4.73±0.33	0.888	4.46±0.50	4.44±0.36	0.924	4.56±0.36	4.51±0.27	0.615
	Rectus abdominis	Left	5.00±0.37	4.79±0.34	0.056	4.66±0.43	4.36±0.40	0.021	4.75±0.44	4.54±0.50	0.125
		Right	5.34±0.55	5.47±0.42	0.255	5.05±0.24	5.11±0.32	0.451	5.13±0.30	5.24±0.38	0.251
	Obliques	Left	22.53±2.78	21.06±2.75	0.085	19.61±2.74	19.40±3.48	0.815	20.74±3.42	18.73±0.48	0.053
		Right	22.78±3.10	18.66±2.99	0.638	18.66±2.99	19.31±2.80	0.466	21.14±2.56	21.23±2.39	0.911
L2–3	Multifidus	Left	4.55±0.43	4.56±0.45	0.972	4.09±0.28	4.11±0.31	0.812	4.40±0.48	4.32±0.53	0.605
		Right	4.35±0.49	4.23±0.20	0.100	3.98±0.43	3.80±0.22	0.125	4.15±0.59	3.84±0.37	0.066
	Erector spinae	Left	10.14±1.04	9.99±1.00	0.349	9.33±2.37	9.26±2.09	0.920	9.57±0.72	9.38±0.76	0.387
		Right	10.27±1.01	10.34±1.56	0.433	8.98±1.08	8.96±1.62	0.945	9.87±0.74	10.33±1.28	0.190
	Ilio-psoas	Left	6.63±0.41	6.73±0.34	0.482	6.28±0.69	6.56±0.34	0.121	6.56±0.31	6.58±0.48	0.869
		Right	6.55±0.39	6.54±0.33	0.855	6.13±0.37	6.23±0.35	0.366	6.20±0.51	6.22±0.39	0.898
	Quadratus lumborum	Left	4.90±0.28	5.00±0.32	0.204	4.63±0.35	4.78±0.48	0.199	4.65±0.41	4.75±0.38	0.403
		Right	4.77±0.35	4.73±0.33	0.888	4.48±0.41	4.44±0.36	0.783	4.60±0.31	4.51±0.27	0.322
	Rectus abdominis	Left	5.00±0.38	4.81±0.36	0.056	4.64±0.43	4.28±0.38	0.006	4.76±0.45	4.52±0.52	0.090
		Right	5.34±0.36	5.47±0.42	0.255	5.04±0.26	5.11±0.32	0.412	5.13±0.30	5.23±0.38	0.319
	Obliques	Left	22.72±2.90	20.88±2.89	0.085	18.44±3.10	17.42±3.60	0.306	21.03±2.98	19.48±3.42	0.105
		Right	22.79±3.17	23.95±3.25	0.638	17.70±3.04	20.99±3.67	0.002	21.60±2.18	22.60±2.11	0.131
L3–L4	Multifidus	Left	4.55±0.44	4.57±0.44	0.896	4.07±0.26	4.10±0.31	0.759	4.34±0.47	4.29±0.62	0.727
		Right	4.38±0.48	4.21±0.23	0.100	3.96±0.41	3.74±0.31	0.055	4.15±0.59	3.84±0.37	0.066
	Erector spinae	Left	12.83±3.39	11.51±2.32	0.112	12.55±3.86	11.65±2.98	0.369	12.46±3.50	11.28±2.34	0.162
		Right	13.15±3.84	11.46±2.51	0.069	12.25±3.35	10.66±1.83	0.034	12.23±3.16	10.75±1.78	0.038
	Ilio-psoas	Left	6.64±0.43	6.71±0.33	0.568	6.30±0.77	6.59±0.42	0.157	6.55±0.31	6.60±0.50	0.693
		Right	6.54±0.39	6.53±0.33	0.918	6.13±0.36	6.06±0.40	0.527	6.21±0.51	6.19±0.36	0.917
	Quadratus lumborum	Left	4.89±0.27	5.00±0.32	0.190	4.63±0.44	4.78±0.47	0.307	4.64±0.40	4.74±0.37	0.400
		Right	4.75±0.36	4.73±0.33	0.846	4.32±0.46	4.33±0.33	0.969	4.56±0.36	4.52±0.25	0.657
	Rectus abdominis	Left	5.01±0.38	4.79±0.34	0.051	4.66±0.43	4.34±0.41	0.016	4.76±0.45	4.53±0.50	0.109
		Right	5.34±0.35	5.52±0.32	0.095	4.99±0.31	5.07±0.29	0.365	5.12±0.29	5.24±0.38	0.198
	Obliques	Left	22.28±2.81	20.96±2.96	0.133	18.64±2.81	18.46±3.85	0.853	20.58±3.40	18.49±4.40	0.070
		Right	22.35±2.97	23.97±3.32	0.087	18.35±2.87	20.58±3.71	0.023	21.56±2.33	23.18±1.64	0.015
L4–L5	Multifidus	Left	7.43±1.51	7.46±1.14	0.959	6.23±1.27	5.83±0.76	0.169	7.45±1.50	7.11±1.23	0.430
		Right	7.25±1.56	6.85±1.00	0.353	6.48±1.42	5.93±0.78	0.083	7.11±1.54	6.77±1.13	0.434
	Erector spinae	Left	9.73±0.52	9.93±0.81	0.314	9.20±0.56	9.43±0.53	0.180	9.43±0.43	9.28±0.64	0.338
		Right	9.66±0.55	9.86±0.46	0.221	9.23±0.55	9.51±0.33	0.029	9.51±0.51	9.48±0.53	0.877
	Ilio-psoas	Left	6.62±0.42	6.71±0.33	0.453	6.41±0.68	6.59±0.42	0.338	6.56±0.33	6.63±0.48	0.559
		Right	6.54±0.39	6.53±0.32	0.917	6.14±0.36	6.05±0.39	0.425	6.21±0.38	6.18±0.40	0.755
	Quadratus lumborum	Left	4.91±0.29	5.00±0.33	0.330	4.63±0.43	4.69±0.51	0.642	4.63±0.41	4.75±0.39	0.346
		Right	4.76±0.36	4.77±0.27	0.860	4.45±0.50	4.49±0.35	0.773	4.55±0.35	4.49±0.27	0.554
	Rectus abdominis	Left	5.03±0.36	4.79±0.34	0.032	4.62±0.45	4.36±0.40	0.058	4.75±0.44	4.54±0.50	0.139
		Right	5.33±0.37	5.47±0.42	0.231	5.03±0.28	5.08±0.33	0.632	5.14±0.31	5.23±0.37	0.430
	Obliques	Left	22.64±2.79	21.29±2.86	0.116	19.69±2.47	18.63±2.99	0.189	20.56±3.47	18.63±3.33	0.067
		Right	22.71±2.40	24.28±2.87	0.047	19.19±3.55	20.28±4.86	0.370	21.15±2.45	21.52±3.26	0.660
L5–S1	Multifidus	Left	9.53±0.95	9.09±0.90	0.124	9.11±0.91	8.78±0.72	0.212	9.18±0.97	9.04±0.94	0.617
		Right	9.65±0.95	9.24±0.72	0.129	8.83±1.23	9.05±1.37	0.562	9.15±1.00	8.85±1.05	0.330
	Erector spinae	Left	9.73±0.52	9.93±0.80	0.284	9.32±0.54	9.56±0.64	0.172	9.43±0.43	9.43±0.44	0.984
		Right	9.65±0.54	9.78±0.49	0.451	9.15±0.66	9.50±0.33	0.014	9.51±0.52	9.51±0.70	0.977
	Ilio-psoas	Left	16.36±1.30	16.39±0.87	0.950	14.66±1.18	15.04±0.96	0.300	14.62±1.55	15.04±1.25	0.365
		Right	14.47±1.98	15.03±1.78	0.369	13.14±2.23	13.98±1.90	0.223	13.88±1.80	14.59±1.39	0.147
	Rectus abdominis	Left	5.01±0.37	4.79±0.34	0.047	4.64±0.44	4.29±0.41	0.008	4.76±0.45	4.54±0.50	0.123
		Right	5.34±0.35	5.47±0.42	0.273	4.99±0.31	5.03±0.32	0.635	5.11±0.30	5.23±0.38	0.237

Values are presented as mean±standard deviation.

CSA, cross-sectional area.

^a)By independent Student t -test.