100 Section - Cryoneurolysis of the Pericapsular Nerve Group (PENG) for Pain Management in Hip Neurogenic Heterotopic Ossification: A Case Series

Neurogenic heterotopic ossification (NHO) is a frequent and disabling complication following central nervous system injury. Pain associated with NHO can significantly impair mobility, participation in rehabilitation, and quality of life. Standard pharmacological treatments often provide limited or transient analgesia. Cryoneurolysis is a minimally invasive technique that induces reversible axonal degeneration, resulting in prolonged pain relief while preserving nerve structure. Its application in NHO-related pain has not yet been described.

Objective:
To report the feasibility and clinical outcomes of ultrasound-guided cryoneurolysis of the Pericapsular Nerve Group for the treatment of pain associated with neurogenic heterotopic ossification of the hip.

Case Description:

Methods:
Three adult male patients with painful hip NHO of neurogenic origin were treated. All patients reported severe pain limiting mobility and participation in rehabilitation programs. Ultrasound-guided percutaneous cryoneurolysis of the PENG was performed using a cryoprobe under sterile conditions. Pain intensity (Numerical Rating Scale), functional tolerance, hip mobility, and ability to participate in rehabilitation were assessed before the intervention and during follow-up.

Discussions:

Results:
All three patients experienced immediate and marked pain relief following the procedure, with pain reduction exceeding 80% compared with baseline. Analgesic effects were observed within minutes to hours after treatment and were sustained over several months of follow-up. This rapid pain reduction was associated with improved hip range of motion, enhanced tolerance to physiotherapy, and the ability to resume or intensify rehabilitation. No adverse events, neurological deficits, or procedure-related complications were reported.

Conclusions:

Conclusion:
Ultrasound-guided PENG cryoneurolysis appears to be a safe and effective option for managing pain associated with neurogenic heterotopic ossification of the hip. The immediate and substantial analgesic effect observed in this case series suggests that this technique may represent a valuable adjunct in rehabilitation medicine. Larger prospective studies are warranted to confirm these preliminary findings and to better define indications and duration of effect.