Delayed diagnosis and worsening of pain following orthopedic surgery in patients with complex regional pain syndrome (CRPS)

Abstract

Background and aims: Complex regional pain syndrome (CRPS) is a serious and disabling chronic pain condition, usually occurring in a limb. There are two main types, CRPS 1 with no definite nerve lesion and CRPS 2 with an identified nerve lesion. CRPS 1 and 2 may occur following an injury (frequently following fractures), surgery or without known cause. An early diagnosis and start of adequate treatment is considered desirable for patients with CRPS. From the clinical experience of the principal investigator, it became apparent that CRPS often remained undiagnosed and that the clinical conditions of many patients seemed to be worsened following orthopedic surgery subsequent to the initial eliciting event. The aim of the present retrospective study of 55 patients, all diagnosed with either CRPS 1 or 2, was to evaluate the time from injury until diagnosis of CRPS and the effect on pain of orthopedic surgical intervention subsequent to the original injury/surgery.

Methods: Clinical symptoms with an emphasis on pain were assessed by going through the patients' records and by information given during the investigation at Oslo University Hospital, where the patients also were examined clinically and with EMG/neurography. Alteration in pain was evaluated in 27 patients who underwent orthopedic surgery subsequent to the eliciting injury.

Results: Of a total of 55 patients, 28 women and 27 men (mean age 38.7 (SD 12.3), 38 patients were diagnosed with CRPS type 1, and 17 with CRPS type 2. Mean time before diagnosis was confirmed was 3.9 years (SD1.42, range 6 months-10 years). The eliciting injuries for both CRPS type 1 and type 2 were fractures, squeeze injuries, blunt injuries, stretch accidents and surgery. A total of 27 patients (14 men and 13 women) were operated from one to 12 times at a later stage (from 6 months to several years) following the initial injury or any primary operation because of fracture. A total of 22 patients reported a worsening of pain following secondary surgical events, while four patients found no alteration and one patient experienced an improvement of pain. None of the 22 patients reporting worsening, were diagnosed with CRPS prior to surgery, while retrospectively, a certain or probable diagnosis of CRPS had been present in 17/22 (77%) patients before their first post-injury surgical event.

Conclusions and implications: A mean time delay of 3.9 years before diagnosis of CRPS is unacceptable. A lack of attention to more subtle signs of autonomic dysfunction may be an important contributing factor for the missing CRPS diagnosis, in particular serious in patients reporting worsening of pain following subsequent orthopedic surgery. It is strongly recommended to consider the diagnosis of CRPS in all patients with a long-lasting pain condition. We emphasize that the present report is not meant as criticism to orthopedic surgical practice, but as a discussion for a hopefully increased awareness and understanding of this disabling pain condition.

Keywords: CRPS; Delayed diagnosis; Orthopedical surgery; Worsening of pain.