Low Level Laser Therapy Versus Short Wave Diathermy in Patients With Anterior Cruciate Ligament Tear

Background \& Rationale: Partial anterior cruciate ligament (ACL) tears are frequent orthopedic injuries, particularly among young adults involved in sports requiring rapid pivoting or directional changes. These injuries often result in pain, instability, muscular weakness, and functional limitations. While complete ACL tears often necessitate surgical reconstruction, partial tears are typically managed with conservative approaches such as physiotherapy and adjunctive non-invasive therapies. Low-Level Laser Therapy (LLLT), or photobiomodulation, is a non-thermal modality that promotes tissue healing through light-induced cellular stimulation. It has shown beneficial effects in reducing inflammation and pain across various musculoskeletal conditions. However, there is limited high-quality evidence evaluating its specific effects on partial ACL injuries or how it compares to widely used modalities like Short Wave Diathermy (SWD). Study Design and Methodology: This is a single-blinded, randomized controlled trial enrolling 72 participants aged 20-40 years with MRI-confirmed partial ACL tears. Participants are randomly assigned (n=36 each) into two groups: Group A (LLLT + SWD + Physiotherapy): Receives Low-Level Laser Therapy in addition to standard physiotherapy and short wave diathermy Group B (SWD + Physiotherapy): Receives standard physiotherapy and short wave diathermy only LLLT Protocol: Wavelength: 830 nm Power Output: 150 mW Power Density: 5 W/cm² Frequency: 2-3 sessions per week for 6 weeks Application Time: 3-4 minutes per treatment site (targeting multiple anatomical points around the knee) Standard Physiotherapy for Both Groups: Exercises: Heel slides, partial knee bends, quadriceps sets, step-ups Repetitions: 2 sets of 10, with 3-5 second rest intervals Short Wave Diathermy Protocol (Both Groups): Frequency: 27.12 MHz Duration: 20-30 minutes per session Application: 2-3 sessions over baseline phase Outcome Measures: Assessments will be conducted at baseline, 3rd week, and 6th week using validated clinical tools: Pain: McGill Pain Questionnaire Muscle Strength: Handheld dynamometer (quadriceps/hamstrings) Functional Disability: KOOS (Knee Injury and Osteoarthritis Outcome Score) Blinding and Randomization: Random allocation via computerized random number generation Single-blinded: Outcome assessors blinded to group assignment Ethical Approval and Consent: Approved by the Ethical Review Committee at the University of Lahore Informed written consent obtained from all participants Privacy and confidentiality strictly maintained Expected Impact: This study aims to provide evidence on whether LLLT offers superior clinical outcomes in pain relief, strength enhancement, and functional recovery compared to SWD in the conservative management of partial ACL injuries. The findings may help refine treatment protocols, promote cost-effective and non-invasive rehabilitation options, and guide physiotherapists in evidence-based practice.