The Effectiveness of High-intensity Laser Therapy on Post-surgical Rehabilitation After Total Knee Arthroplasty

Summary

This randomized controlled trial aims to evaluate the effectiveness of high-intensity laser therapy (HILT) as an adjunct to conventional rehabilitation in patients undergoing total knee arthroplasty (TKA).

Persistent pain and functional limitations are common after TKA despite standard rehabilitation, highlighting the need for adjunctive therapies to optimize postoperative recovery. High-intensity laser therapy has been proposed as a non-invasive intervention with potential analgesic and anti-inflammatory effects; however, its effectiveness in this population remains unclear.

Participants will be randomly allocated to one of two groups: an experimental group receiving HILT in addition to conventional physiotherapy and a control group receiving sham laser therapy combined with the same rehabilitation program. Both groups will undergo standardized rehabilitation sessions lasting 60 minutes, including 15 minutes of active or sham laser therapy and 45 minutes of conventional physiotherapy.

The primary outcome is postoperative pain. Secondary outcomes include joint swelling, range of motion, muscle strength, physical function, and quality of life.

Assessments will be conducted at baseline (preoperative), at 1 month after surgery (prior to the start of rehabilitation), during the rehabilitation program (after the fourth, seventh, and tenth physiotherapy sessions), and at 4 months postoperatively (follow-up).

A total of 46 participants (23 per group) will be enrolled in the study.

Conditions

• Arthroplasty Complications
• Pain, Postoperative

Interventions

DEVICE

High level laser therapy

High-intensity laser therapy (HILT) will be delivered using the HIRO TT device (ASA S.r.l.), which employs a patented pulsed laser system (FDA-approved in 2003) based on a solid-state Nd:YAG source emitting near-infrared (NIR) radiation at a wavelength of 1064 nm. The device operates with a mean power of 10.5 W and a peak power of 3 kW. Three treatment areas (each measuring 15 × 10 cm) will be targeted: two longitudinal areas over the quadriceps muscle and one transverse area over the knee joint. The treatment will be delivered at a frequency of 15 Hz, with a total energy dose of 2000 J, corresponding to an energy density of 4.5 J/cm². The total treatment time will be 14 minutes and 30 seconds.

OTHER

Sham laser therapy

The sham laser intervention will be delivered using the same HIRO TT device and identical treatment procedures as the active HILT group. The same anatomical areas (two longitudinal areas over the quadriceps muscle and one transverse area over the knee joint) will be targeted, with identical session duration and positioning. During sham treatment, the device will remain switched on; however, no therapeutic laser emission will be delivered. This approach is intended to ensure participant blinding by replicating the visual and procedural aspects of the active intervention without providing any active therapeutic effect.

Sponsors & Collaborators

• Istituto Ortopedico Rizzoli

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

50 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-09-30

Primary Completion

2027-09-30

Completion

2028-09-30

Countries

• Italy

Study Locations