Complex Regional Pain Syndrome in Distal Radius Fractures

Importance of the Problem

Complex regional pain syndrome (CRPS) type I is defined as chronic pain without an identifiable nerve injury and is one of the principal causes of long-term disability following distal radius fractures. Pain is accompanied by trophic changes, impaired function, and finger stiffness as well as autonomic dysfunction ( Fig. 1 ). Patients with fibromyalgia, women, and smokers have a higher likelihood of developing this condition. Incidence of DRFs complicated by CRPS varies and is reported to affect 1%–37% of patients ; however, the etiology of this complication is not well understood. It has been correlated to tight casts and over distraction of the wrist joint with spanning external fixators ( Fig. 2 ), but these scenarios only account for a small fraction of the known clinical scenarios. Surgical decompression, particularly of the median nerve, has been shown to be effective in modulating the sequelae of CRPS associated with a DRF.

Diagnosis of CRPS is challenging as it is based on clinical criteria ( Box 1 ) with mainly subjective components. Several diagnosis algorithms have been published over the years and currently, the most validated and internationally accepted is the Budapest Criteria ( Box 1 ). Radiographs may show disuse osteoporosis and peri-articular demineralization. Bone scan may show increased uptake, especially in phase 3 of the scan, but has low sensitivity. In general, imaging studies should be interpreted in light of the clinical findings and are usually not essential to diagnose CRPS. Early diagnosis is possible even 2 weeks after the injury and is associated with recovery in 80%–90% of cases. Late diagnosis of CRPS and inappropriate treatment can lead to chronic CRPS with residual pain and long-term disability up to 10 years after the injury with significant sociomedical and welfare consequences. Conversely, some prominent hand surgeons claim that CRPS does not exist and the symptoms can be explained by another pathology that was overlooked such as subclinical nerve compression, undetected nonunion, or fracture malreduction. Certainly, imaging and other advanced studies should be performed to rule out any pathology that may cause disproportional pain that may have been overlooked.

The purpose of treatment of CRPS in DRFs is to restore the affected upper extremity within the acceptable mobility and durability requirements. There are many treatment modalities to treat CRPS, most with poor supporting evidence. Treatments such as bisphosphonates, N -acetylcysteine, glucocorticoids, calcitonin, pregabalin, gabapentin, antidepressant, antiepileptic drugs, clonidine, epidural infusion systems, and neurostimulation have all been reported yet limited studies exist. However, there has been extensive research regarding the role of vitamin C in the treatment of CRPS in patients with DRFs as well as literature regarding the role of physical therapy and cognitive behavioral therapy. These latter treatment modalities will be the focus of this chapter.

Main Question

How can CRPS type-1 be effectively prevented, diagnosed, and/or treated in patients with DRF?

Current Opinion

The diagnosis of CRPS remains challenged and debated because of its lacking objectifiable character and etiologic understanding. Several treatment modalities have been offered over the years to treat CRPS following DRF, most with poor supporting evidence. There is an ongoing debate, accompanied by high quality evidence, about the role of Vitamin C in the prevention of CRPS. Other areas of controversy relate to the role of physical therapy with behavioral components in the treatment of CRPS and if there is an association between the distal radius fixation method to the occurrence of CRPS. Additionally, in recent years, a paradigm shift among surgeons has developed to find the culprit of the pain and offer surgical treatment. This paradigm shift is currently supported mainly by expert opinion and case series.

Finding the Evidence

The search was conducted in MEDLINE via PubMed and the Cochrane library. The search terms were broad and included the intervention (“vitamin C,” “physiotherapy,” “physical therapy,” “psychotherapy,” “cognitive behavioral therapy,” “nerve block,” “cast,” “external fixation,” “open reduction internal fixation”), population (“wrist fracture,” “distal radius fracture”), and disease of interest [“complex regional pain syndrome (or CRPS),” “reflex sympathetic dystrophy (or RSD),” “Sudeck's atrophy”]. Additionally, we searched for review articles of CRPS in DRF using the general terms “distal radius fracture” and “CRPS.” No time limits were set. The reference list of the review articles and metanalyses retrieved were additionally reviewed to identify other papers not included in our other broader search.

Quality of Evidence

We attempted to limit our examination to level I or II prospective randomized trials and metanalyses. However, to better define the role of surgery in the treatment of CRPS, we included several case series.

• Level I—4 randomized controlled trials, 5 systematic review and metanalysis.

• Level II—3 randomized controlled trials with methodological limitations.

• Level III—5 case series.