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World J Orthop. Jul 18, 2026; 17(7): 121157
Published online Jul 18, 2026. doi: 10.5312/wjo.121157
Early oral celecoxib prevents contracture and modulates capsular fibrosis in a validated model of post-traumatic arthrofibrosis
Luis Palacios-Díaz, Blanca Diez Sánchez, Ángel González-García, Eva Manuela Pena-Burgos, José Juan Pozo-Kreilinger, MT Carrascal-Morillo, Alejandro Bustos, Pablo Sanchez-Urgelles, Samuel Antuña, Raul Barco
Luis Palacios-Díaz, Blanca Diez Sánchez, Ángel González-García, Pablo Sanchez-Urgelles, Samuel Antuña, Raul Barco, Department of Shoulder and Elbow Surgery, La Paz University Hospital, Madrid 28046, Spain
Eva Manuela Pena-Burgos, Pathology Department, Gregorio Marañón University Hospital, Madrid 28007, Spain
José Juan Pozo-Kreilinger, Pathology Department, La Paz University Hospital, Madrid 28046, Spain
MT Carrascal-Morillo, Alejandro Bustos, Department of Mechanics, School of Industrial Engineering, UNED, Madrid 28040, Spain
Author contributions: Palacios-Díaz L, Antuña S, and Barco R conceived and designed the study; Palacios-Díaz L, Diez Sánchez B, González-García Á, and Sanchez-Urgelles P performed the experiments and data collection; Pena-Burgos EM and Pozo-Kreilinger JJ conducted the histological analysis; Carrascal-Morillo MT and Bustos A performed the biomechanical analysis; Palacios-Díaz L and González-García Á analyzed the data; Palacios-Díaz L drafted the manuscript. All authors contributed to manuscript revision and approved the final version.
AI contribution statement: ChatGPT was used solely to assist with language editing and improvement of the manuscript’s readability. The authors were entirely responsible for the study conception and design, data collection, data analysis, interpretation of results, manuscript content, and responses to reviewers. All AI-assisted text was carefully reviewed, edited, and approved by the authors, who take full responsibility for the final content of the manuscript.
Supported by SECEC 17th Basic Research Grant; and SECOT Ayudas a Investigación en COT 2024.
Institutional animal care and use committee statement: This study was approved by the Animal Experimentation Committee at La Paz University Hospital (approval No. PROEX 227.6/23; 29/09/2023).
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Data sharing statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.
Corresponding author: Luis Palacios-Díaz, Department of Shoulder and Elbow Surgery, La Paz University Hospital, Paseo de la castellana 291, Madrid 28031, Spain.
lpalaciosdiaz96@gmail.com
Received: March 18, 2026
Revised: April 9, 2026
Accepted: June 8, 2026
Published online: July 18, 2026
Processing time: 115 Days and 16.6 Hours
BACKGROUND
Post-traumatic arthrofibrosis results from excessive joint capsule fibrosis. Current treatments are limited to physiotherapy or surgical release, and no reliable preventive therapy exists. Celecoxib may reduce stiffness, but its preventive effect on capsular arthrofibrosis remains unproven.
AIM
To evaluate the effect of oral celecoxib on joint contracture and posterior capsular fibrosis in a validated rat model.
METHODS
Forty 14-week-old female Sprague Dawley rats underwent right knee surgery including intra-articular injury, posterior capsule disruption and immobilization for 4 weeks, followed by 4 weeks of remobilization. Two groups (control and celecoxib) of 20 rats each were divided so that 10 rats were assessed for biomechanical contracture - measuring passive extension angle (PEA) at different torques and calculating elastic torque, stiffness, and energy absorbed - while the remaining 10 rats were used to quantify posterior capsule area and thickness and to evaluate fibrotic tissue using a semiquantitative scale. All measurements were performed in a blinded manner by engineers or pathologists. The celecoxib group received oral celecoxib (50 mg/kg/24 hours) for 2 weeks after surgery.
RESULTS
All rats gained weight appropriately and celecoxib was well tolerated. Operated knees in the celecoxib group showed greater PEA at higher torques [PEA-8 N·cm: 38.6° (95% confidence interval: 5.3-72.0), P = 0.026; PEA at failure: 84.4°, P = 0.015], higher failure torque (17.6 N·cm, P = 0.002) and higher elastic torque (14.9 N·cm, P = 0.009) compared to operated knees in the control group. Histologically, operated knees in the celecoxib group exhibited greater amount of fibrous connective tissue [1.5 interquartile range (IR): 1.25-1.0; P = 0.003], higher cellular density [1.0 (IR: 0.25-2.0); P = 0.027) and increased vascularity [1.0 (IR: 0.5-1.0); P = 0.030] compared to controls.
CONCLUSION
This study provides the first experimental evidence that early oral celecoxib can prevent or limit post-traumatic arthrofibrosis of capsular origin, reducing joint contracture and modulating posterior capsular fibrosis toward a more active, immature tissue phenotype.
Core Tip: Post-traumatic arthrofibrosis remains a challenging condition with limited preventive strategies. In this rat model, celecoxib reduced capsular fibrosis and improved biomechanical outcomes, suggesting a potential disease-modifying effect on fibrotic remodeling rather than solely providing symptomatic relief. These findings support further investigation of celecoxib as a preventive intervention for post-traumatic joint contracture and provide a rationale for future translational and clinical studies.
