TITLE:
Effect of Intra Discal High-Frequency Ultrasound Application in Degenerative Disc Disease: A Seamless Sequential Translational Ex Vivo and In Vivo Study
AUTHORS:
Johan, Chua Wen Yi, Bhavneet Singh Bhalla, Rajneesh Kumar Mishra
KEYWORDS:
Degenerative Disc Disease, Disc Bulging, High-Frequency Ultrasound, Translational Research for Disc Bulging
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.15 No.11,
November
28,
2025
ABSTRACT: Background: Degenerative Disc Disease (DDD) is a highly prevalent condition, with over 400 million people estimated to experience symptomatic DDD annually as of 2018 [1]. Its prevalence increases significantly with age [2]. Despite its widespread occurrence, definitive treatment options for DDD remain limited to surgical interventions. These include procedures such as discectomy with fusion and other invasive techniques [3]. However, many elderly patients are not suitable candidates for surgery due to multiple comorbidities. Therefore, the importance of searching for a novel, effective, minimally invasive treatment is paramount. Study Design: A seamless sequential ex vivo and in vivo translational animal study has been conducted to evaluate the dose-finding matrix and the efficacy of intra-discal high-frequency ultrasound (HF-US) application in treating mechanically and surgically-induced hyper-acute disc bulging in a porcine model, for ex vivo and in vivo, respectively. Materials and Methods: Mechanical disc prolapse was induced through rhythmic spinal flexion and axial compression, and surgical prolapse was generated by annulotomy using 14 G Veress needle puncture on the spinal functional unit (SFU) (lumbar vertebra-disc-lumbar vertebra) from L1 - L6. Disc bulging observed by direct visualization in L3/L4, L4/L5 and L5/L6 (>25% disc protrusion from baseline), and L4/L5, L5/L6 demonstrated with indocyanine green intra-discal injection observed with special laparoscopic camera marking with >25% disc protrusion from baseline and reduced in IVD disc height, for ex vivo and in vivo subjects, respectively. Intra-discal HF-US applied in multiple frequencies, power/acoustic intensity, exposure duration, and duty cycle has been conducted during the ex vivo study to determine the dose matrix. Once the optimal treatment measurement was obtained during ex vivo, a seamless, sequential in vivo test conducted using the same parameters with HF-US. The healthy spines have been used as control, treated with sham energy source. Result and conclusion: Results demonstrated that treatment with high-frequency ultrasound significantly reduced disc bulging and restored the intervertebral disc height in the intervention group compared to the control group.