Background/Purpose: Although the overall outcome of total knee arthroplasty (TKA) is favorable, surgery alone fails to resolve many of the substantial functional limitations and physical inactivity that began long before the surgery. To improve these persistent limitations, exercise programs need to be performed at doses sufficiently high to promote sizable improvements in physical function (PF). In addition, physical activity (PA) promotion should be part of the rehab program. The aim of this study was to determine the effectiveness of comprehensive behavioral intervention (CBI) – that uses intense exercises and promotes activity participation – compared to a standard of care (SC) exercise program to improve PF and PA in patients after TKA.

Methods: Double blinded pilot randomized clinical trial. Patients who underwent unilateral TKA 3 – 6 months prior were assigned into 2 groups, the CBI or SC. Subjects in both groups completed 12 weeks of supervised exercise followed by 12 weeks of exercise program.  Clinical outcomes were collected prior to (baseline) and after intervention (6 months). Self-reported PF was measured by the Western Ontario and McMaster Universities Arthritis Index- PF score (WOMAC-PF) and the PF subscale of the RAND-36. Patient-identified problem areas in daily functioning were measured by the Canadian Occupational Performance Measure (COPM), which considers both the importance and the satisfaction with the performance areas.   Performance-based PF was measured by the chair-raise test, gait velocity, and the stair climbing test. An objective accelerometer-based monitor was used to quantify PA during light (2 to 2.99 metabolic equivalents – METs) and moderate intensities (above 3 METs). Changes between groups were compared using independent sample t-test or Wilcoxon according with data distribution.

Results: Sample included 44 subjects (70% female, age 68 ± 0.98 years, and BMI 30.0 ± 0.6 Kg/m2). Results are reported in the Table. Both groups reported improved PF. PF measured by the RAND-36 was statistically significant larger in the CBI than in the SC, whereas group differences in the WOMAC- PF did not reach significance. Both groups improved performance and satisfaction in the COPM. Subjects in the CBI group significantly improved in the Stair Climb test compared to the SC group. Group differences in gait velocity and chair-raise test were not significant. While not significant, subjects in the SC group decreased PA while the ones in the CBI increased PA.

Conclusion: Subjects in the CBI group experienced larger improvements in PF as measured by the RAND-36 and the stair climbing test. Although we observed a trend towards larger changes in COPM-satisfaction and light intensity PA in the CBI group, the negative results may be due to the small sample of this pilot study.  Results indicate that the CBI may be a promising intervention for patients post TKA.

Table.  Baseline and 6-month physical function and physical activity outcomes in the CBI and SC groups. Data represent mean ± SD or median (Q25; Q75).
	Group	Baseline	6 months	Change (6 mo – baseline)	Percentage Change	p-value
WOMAC – Physical Function*	SC	17.68 ± 2.21	12.8 ± 2.42	-5.35 ± 2.09	-30%	0.503
	CBI	19.09 ± 1.99	11.42 ± 1.50	-7.05 ± 1.34	– 37%
RAND-36 – Physical Function**	SC	66.14 ± 3.97	70.25 ± 5.41	6.75 ± 3.86	10%	0.037
	CBI	56.14 ± 4.80	76.05 ± 3.74	16.58 ± 2.30	30%
COPM – Performance**	SC	36.38 ± 2.71	59.74 ± 5.74	23.18 ± 4.48	64%	0.360
	CBI	34.27 ± 3.16	63.34 ± 4.70	29.0 ± 4.39	85%
COPM – Satisfaction**	SC	27.63 ± 3.26	56.70 ± 6.78	28.62 ± 5.50	104%	0.176
	CBI	22.36 ± 2.74	61.93 ± 5.37	39.15 ± 5.27	175%
Chair-raise Test (sec)	SC	13.16 ± 0.68	13.74 ± 1.67	0.68 ± 1.53	5%	0.444
	CBI	14.26 ± 0.81	11.97 ± 0.63	-1.69 ± 0.40	– 12%
Gait Velocity (m/sec)	SC	1.106 ± 0.38	1.183 ± 0.06	0.06 ± 0.04	6%	0.679
	CBI	1.037 ± 0.04	1.147 ± 0.04	0.08 ± 0.03	8%
Stair Climbing Test (sec)	SC	15.5 ± 0.997	15.59 ± 1.66	0.07 ± 1.47	0.5%	0.006
	CBI	19.03 ± 1.54	14.19 ± 0.98	-4.43 ± 1.00	– 23%
Light Intensity PA  (min/d)	SC	123.5 (82.5; 176.8)	83.5 (42.0; 158.0)	-5.5 (-62.8; 14.0)	– 5%	0.167
	CBI	99.5 (44.8; 157.5)	124.0 (61.0; 142.0)	12.0 (-26.0; 21.0)	12%
Moderate Intensity PA (min/d)	SC	38.5 (18.3; 70.8)	33.0 (17.3; 61.8)	-1.0 (-25.3; 21.8)	– 3%	0.999
	CBI	24.5 (9.3; 47.8)	34.5 (12.5; 47.7)	4.5 (-23.5; 12.0)	18%
*Lower scores represent better function; ** Higher scores represent better function

---

« Back to 2013 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/comprehensive-behavioral-intervention-compared-to-standard-of-care-exercise-program-after-total-knee-arthroplasty-a-pilot-randomized-trial/