Ultrasound-guided Hydrodissection and Integrated Rehabilitation for Postsurgical Common Peroneal Nerve Entrapment

Summary

This article demonstrates ultrasound-guided hydrodissection and a structured, task-oriented rehabilitation program for postsurgical common peroneal nerve entrapment.

Abstract

Postoperative common peroneal nerve (CPN) entrapment is a common iatrogenic cause of foot drop, and an established rehabilitation protocol is currently lacking. This article provides a step-by-step visual demonstration of an integrated approach, combining ultrasound-guided hydrodissection with structured task-oriented rehabilitation. The protocol includes: (1) real-time ultrasound identification of CPN entrapment; (2) in-plane, multi-quadrant hydrodissection using a 5% dextrose, lidocaine, and mecobalamin injectate; and (3) a phased rehabilitation program initiated 24 h post procedure, comprising neural gliding, therapeutic ultrasound, neuromuscular electrical stimulation, and five task-oriented training modules. In the representative case, the leg-foot angle during maximal dorsiflexion effort demonstrated a 38° reduction (from 142° to 104°), and gait analysis showed restoration of heel-strike, push-off, and swing-phase foot clearance. Post-intervention EMG revealed reinnervation potentials in the tibialis anterior, peroneus longus, and extensor hallucis longus. This visually formatted, stepwise protocol demonstrates the feasibility of combining percutaneous nerve decompression with task-specific rehabilitation, offering a replicable framework for managing refractory postoperative CPN entrapment.

Introduction

Postoperative common peroneal nerve (CPN) dysfunction is a significant cause of morbidity. While direct intraoperative injury (e.g., from knee dislocation or fibular fracture) is a well-recognized etiology^1,2, a more insidious and frequently overlooked mechanism is delayed entrapment by postoperative fibrotic scar tissue². Unlike acute structural damage, this scarring forms progressively, creating a chronic compressive barrier around the nerve. This compression not only mechanically tethers the nerve, impeding axonal transport, but also critically compromises its microvascular blood sup....

Protocol

All procedures were performed in accordance with the ethical standards of the institutional research committee and with patient-informed consent. This protocol was approved by the Ethics Committee of Wenzhou TCM Hospital of Zhejiang Chinese Medical University (Approval Number: WZY2025-LW-068-02).

1. Ultrasound-guided hydrodissection for CPN entrapment

NOTE: In this demonstration, a single session was performed. Repeat intervention, if considered, should be based on persistent functional deficits or sonographic evidence of residual entrapment, with the frequency and total number individualized; evid....

Results

Functional recovery
Following the integrated protocol, the leg-foot angle during maximal voluntary dorsiflexion improved from 142° pre-intervention to 104° post-intervention, representing a 38° reduction (measured in seated position; Figure 3). This functional gain was accompanied by normalization of gait biomechanics. Pre-treatment gait analysis showed characteristic impairments of common peroneal nerve (CPN) palsy, including forefoot strike at initial contact (

Discussion

This article demonstrates an integrated approach that combines ultrasound-guided hydrodissection with structured rehabilitation for the management of refractory common peroneal nerve (CPN) entrapment. The observed functional recovery illustrates a potential synergy: precise structural intervention creates the necessary physical conditions, which neuromotor retraining may then exploit to restore function.

The successful execution of the procedure depends on several key, visually guided ste.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
50% Glucose Injection	China Otsuka Pharmaceutical Co., Ltd.	25G95J1	Component of injectate (1 mL, 5% final concentration)
Adhesive Dressing	Zhende Medical Co., Ltd.	N2206070111-2	Cover needle insertion site post-procedure
Balance Pad	Zhangjiagang Aonfit Trading Co., Ltd.	ATZJ383	Progression tool for single-leg standing training
Blunt-Tip Nerve Block Needle (22 G or 25 G, 50–80 mm)	Zhejiang Kindly Medical Devices Co., Ltd.	C20251117	For in-plane ultrasound-guided hydrodissection
Foam Blocks	Zhangjiagang Aonfit Trading Co., Ltd.	ATY0520	Obstacles for level-ground crossing training
Iodophor Disinfectant	Shandong Xiaoboshi Disinfection Technology Co., Ltd.	20250902K	Skin disinfection before needle insertion
Lidocaine Injection	Hunan Kelun Pharmaceutical Co., Ltd.	R24101103	Component of injectate
Mecobalamin Injection	Eisai China Inc.	230658	Neurotrophic support in injectate (1 mL)
Medical Underpad	Zhende Medical Supplies Co., Ltd.	20250911C	Protect patient positioning surface
Neuromuscular Electrical Stimulation Device	Beijing Yaoyangkangda Medical Equipment Co., Ltd.	KT-90B	Must deliver biphasic square wave.
Sodium Chloride Injection (0.9%)	China Otsuka Pharmaceutical Co., Ltd.	25I89B4	Diluent for injectate
Soft Soccer Ball	Peak (China) Co., Ltd.	YQ03207	Target for lateral ball-kicking training
Sterile Gauze	Henan Yadu Industrial Co., Ltd.	2509CA3138	Apply pressure to puncture site
Sterile Latex Gloves	Beijing Ruijing Latex Products Co., Ltd.	2025072425	Maintain aseptic technique
Sterile Probe Cover	Zhejiang Chun'an County Renhe Medical Products Industry and Trade Co., Ltd.	A1440EP	Sterile cover for ultrasound probe
Sterile Syringe (10 mL)	Zhejiang Longde Pharmaceutical Co., Ltd.	202601076	Prepare total injectate volume (10 mL)
Therapeutic Ultrasound Device	Shanghai Xibei Huachao Intelligent Medical Technology Co., Ltd.	Sonosail 2	With 1 MHz transducer head for pulsed application.
Ultrasound Gel	Hangzhou Kaipule Medical Equipment Co., Ltd.	KL-250	Acoustic coupling for ultrasound imaging
Ultrasound System	Fujifilm SonoSite Co., Ltd.	SII	With color Doppler function. Use high-frequency linear array transducer (10–15 MHz).