Long Duration Ultrasound Combined with Platelet-Rich Plasma Injection for Return to Sport after Soft Tissue Injury: A Single Center Study

Abstract

Objective: The use of Long-Duration Ultrasound (LDU) and Platelet-Rich Plasma (PRP) treatments to facilitate injury healing and pain relief are typically utilized independently in sports medicine. Our study aimed to investigate the combined regenerative effect of daily LDU with high-concentration single-injection PRP for treating sport-related musculoskeletal injuries.

Methods: In total, thirty-five competitive athletes (n=35) with grade II sprains and strains and tendinopathies injured during sport and unable to continue to play were sequentially administered PRP (n=20, 20.4 yoa, 18 male, 2 female) or PRP+LDU (n=15, 20.27 yoa, 14 male, 1 female). In the PRP treatment group, each subject was treated with a single injection of PRP consisting of 1.28 billion platelets/mL under ultrasound-image guidance to the injury site. The PRP+LDU treatment group received the same PRP injection procedure with a 14-day, 4 hr per day, 18,720 J ultrasound treatment applied over the injection site. The Numeric Ration pain Scale (NRS, 0-10), Range of Motion (ROM, 0-100%), Clinical Strength numeric score (CS, 0-5), and time of injury to return to sport (days) were measured at baseline and Return to Play (RTP). The global health improvement score (GROC -7 to +7) was measured upon RTP.

Results: All patients completed rehabilitation and returned to the sport after debilitating injuries. PRP+LDU returned athletes to play 21.33 days quicker (p<0.0001), decreased injury pain by 0.88 NRS points (p=0.0086), and improved patient global health by 1.28 points GROC (p<0.0001) over PRP treatment alone (95% Confidence interval, 11.26 to 31.40 days faster). There were no significant differences in strength (p=0.498) or range of motion (p=0.8581) improvement between PRP and PRP+LDU at the RTP or baseline patient demographic variables.

Conclusion: Adding LDU at-home treatment to PRP injection therapy significantly reduces the time to return to sport, increases pain reduction, and improves overall health for patients recovering from sport-related injury. The daily LDU treatment facilitates and enhances regenerative medicine therapies such as PRP.

Keywords: Long duration ultrasound; Platelet rich plasma; Regenerative medicine; Return to sport; Sports medicine; Sustained acoustic medicine.

Figure 1:

Study flowchart illustrating study design. Note: Numeric Ratting Scale (NRS); Range of Motion (ROM); Platelet Rich Plasma (PRP); Long Duration Ultrasound (LDU); and General Rate of Change (GROC).

Figure 2:

Return To Play (RTP) analysis. a) Pain reduction on NRS scale (0: No reduction, 10: No pain at RTP); b) Pain reduction on GROC scale (0: No improvement, 7: Complete improvement); c) Impact on the reduction of RTP duration during the reason. *P=<0.05, ***P<0.0001. Note: (■) PRP; (■) PRP+LDU.