To determine whether pre- and post-operative conditioning of the surgical site with photobiomodulation (PBM) improves post-operative functional recovery compared to sham treatment.
A participant, assessor and statistician-blinded, randomized, sham-controlled clinical trial compared sham and active self-adhesive, printed LED light patches (CareWear Wearable Therapeutics (USA); high frequency pulsed @450nm and 640nm; 30mins daily for 7-days pre-op and 14-days post-op; total delivered fluence per treatment = 4.5J/cm2) to the knee joint, posterior knee lymphatics and quadriceps muscle. Male and female participants (aged 60-85 years) undergoing elective unilateral TKA were allocated using 2-4 random-permuted block randomization to either active treatment (AT group) or sham treatment (ST group). Treatment commenced once baseline measurements were collected. Measures: 40m fast-paced walk test (FPWT) and timed-up-and-go (TUG) test at baseline (one week prior to TKA), one day prior to TKA, at 4- and 7-days post-op, and 2, 4 and 6 weeks after TKA. At each time-point, mean difference in FPWT and TUG between groups was compared. Univariate analysis of mean difference between groups was assessed using Welsh Two sample t-test, or Kruskal-Wallis rank sum test for non-normally distributed data. Fisher’s Exact test was used to test for group differences with categorical data.
Of 60 participants recruited, 59 were eligible for analysis (29 AT group, 30 ST group; one excluded due to significant diversion from protocol). At baseline, there was no statistical difference between the AT and ST groups in participant characteristics, FPWT (AT group 4.6s faster) or TUG (AT group 0.58s faster). At one day pre-TKA, mean time to complete FPWT was 5.8s faster in the AT group compared to ST group (P =0.5). At Day+4 post-op, the AT group took 29s less than the ST group (P = 0.2) to complete the FPWT (Active vs Sham Mean (SD): 85 (42), 114 (61)), a clinically meaningful effect. At each subsequent visit, the AT group took less time than ST group to complete the FPWT, with mean difference between groups reducing over time (NS) (Visit Mean difference (s): 7 days -13, 2 weeks -12, 4 weeks -0.77, 6 weeks -0.72). For TUG test, mean difference between groups pre-surgery was 1s. At 4 days post-surgery, AT group took 4.7s less on average to complete TUG, than ST group (NS). Subsequently, AT group took less time than ST group to complete TUG, with mean difference between groups reducing with each visit (NS) (Visit Mean difference (s): 7 days -2.4, 2 weeks -1.2, 4 weeks 0.98, 6 weeks 0.28).
PBM as a tissue conditioning agent was effective as participants receiving active treatment demonstrated markedly decreased time to complete functional tests during early recovery post-TKA. Correlating pain scores and analgesic use with functional scores will be useful.
The use of PBM can be recommended as a peri-operative tissue conditioning agent to aid in functional recovery after TKA especially if rapid discharge approaches are being used.
functional recovery
outcome measures
