Niveles plasmáticos de sustancia P en cirugía artroscópica del hombro. ¿Son útiles en la prevención de la capsulitis posquirúrgica?

Abstract

Objectives

To determine the plasma levels of neuropeptide substance P (SP) in patients with chronic subacromial pain due to rotator cuff pathology. To evaluate the correlation between pre and postoperative plasma levels of SP, chronic postoperative pain and postoperative stiffness.

Methods

Prospective, controlled, observational study of 60 consecutive patients with rotator cuff pathology undergoing shoulder arthroscopy with interscalene nerve block. An additional 15 patients with instability without cuff pathology were included as control group. Plasma samples were obtained preoperatively, at 2 hours postoperatively, the day after surgery, and 6 weeks later. Visual analog pain scores and range of motion were registered at 6 weeks.

Results

Preoperative plasma SP levels in patients with rotator cuff pathology were significantly greater than those in the instability control group. Plasma SP levels were sharply decreased soon after surgery in both groups. A statistical correlation was obtained between the sharp fall of circulating plasma SP levels, immediately after surgery, and pain with or without stiffness 6 weeks later.

Conclusion

Patients with pain, with or without stiffness, 6 weeks after arthroscopic surgery for rotator cuff pathology, could have altered peripheral and central pain processing pathways, as suggested by the differences in circulating plasma SP levels observed.

Level of evidence

2A. Non-randomized prospective study.

Clinical relevance

Measurement of neuropeptide SP in the clinical setting has the potential of being used as a prognostic aid to guide individual patient treatment or even to be used as a surrogate outcome measure in trials.