Complex Regional Pain Syndrome (CRPS)¶
What CRPS is, why it sometimes follows a wrist or hand injury or operation, how it is recognised and treated, and what recovery looks like.
Overview¶
Complex Regional Pain Syndrome (CRPS) is a multifactorial condition requiring further study to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3]. Diagnosis is clinical, based on history and physical examination [9]. Early recognition and prompt treatment of CRPS are important to minimize permanent loss of function, although patients may still experience permanent impairment and disability [9]. A more active treatment approach appears to lower the incidence of CRPS-1 [2].
The reported incidence of CRPS Type I within four months of a wrist fracture is influenced by the choice of diagnostic criteria, study location, and fracture management [15]. In contrast, the incidence of CRPS following isolated cubital tunnel surgery is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33% [10]. Quantitative sensory testing outcomes indicate altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5]. The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4].
For management, in patients with chronic or refractory CRPS, strong consideration should be given for the use of ketamine [1]. Prednisolone is a potential treatment option for CRPS, particularly in resource-limited settings where specialized interventions may be unavailable [6]. High-intensity laser therapy (HILT) provides conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7]. However, the methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8].
Background & Causes¶
CRPS is a multifactorial condition requiring further study to understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3]. Altered pain mechanisms exist in CRPS compared with controls, with a pooled standardized mean difference of -0.41 in quantitative sensory testing outcomes [5]. The diagnosis of CRPS is clinical, based on history and physical examination [9]. Early recognition and prompt treatment are important to minimize permanent loss of function, although patients may still experience permanent impairment and disability [9].
The incidence of CRPS varies by procedure and patient population. Following isolated cubital tunnel surgery (CuTS), CRPS is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33% [10]. In patients treated for Dupuytren contracture, female sex and the release of more than one digit are significant predictors of developing CRPS [11]. Elderly patients, females, and manual laborers have higher risks of developing CRPS after distal radius fracture surgery [13]. Patients with scaphoid waist fracture may be at higher risk of CRPS type I, especially women with diabetes mellitus who report severe pain before treatment [19]. Preexisting neuropathic disorders, particularly traumatic nerve injuries, compressive neuropathies, and cervical radiculopathy, are the strongest predictors of CRPS after distal radius fracture [17]. Additionally, CRPS-related hand lesions developed in 19.4% of patients following arthroscopic rotator cuff repair (ARCR) [14].
Conversely, a large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release [12].
Symptoms & Presentation¶
CRPS is a multifactorial condition [3]. Quantitative sensory testing indicates altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5]. Pain is a highly debilitating symptom in CRPS-I [7].
The diagnosis of CRPS is a clinical diagnosis based on history and physical examination [9]. The diagnosis of CRPS should only be a diagnosis of exclusion [18]. Early recognition and prompt treatment are important to minimize permanent loss of function in CRPS [9]. Patients with CRPS may still experience permanent impairment and disability despite treatment [9].
The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4]. Glomus tumors should be included in the differential diagnosis for patients with unusual chronic pain or neuropathy [18].
Management¶
Diagnosis and Assessment: The diagnosis of CRPS is clinical, based on history and physical examination [9]. The Hamilton Inventory reliably assesses CRPS symptoms, functional limitations, and psychosocial impacts [4]. Quantitative sensory testing indicates altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5]. Early recognition and prompt treatment are important to minimize permanent loss of function, although patients may still experience permanent impairment and disability [9].
Risk Stratification: The incidence of CRPS following isolated cubital tunnel surgery is approximately 0.33% at 1 year [10]. Female sex is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11]. Release of more than one digit is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11]. Elderly patients have higher risks of developing CRPS after distal radius fracture surgery [13]. Female patients have higher risks of developing CRPS after distal radius fracture surgery [13]. Manual laborers have higher risks of developing CRPS after distal radius fracture surgery [13].
Pharmacological and Interventional Therapies: Strong consideration should be given for the use of ketamine in patients presenting with chronic or refractory CRPS [1]. Prednisolone has potential as a treatment option for CRPS, particularly in resource-limited settings where more specialized interventions may be unavailable [6]. High-intensity laser therapy (HILT) offers conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7].
Surgical and Procedural Outcomes: A more active treatment approach seems to lower the incidence of CRPS-1 [2]. A large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release [12]. The positive outcome for a patient with Dupuytren’s contracture and CRPS-I after collagenase clostridium histolyticum (CCH) injection is encouraging [16]. The methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8].
Key Considerations¶
Diagnosis and Assessment: CRPS diagnosis is clinical, based on history and physical examination, with early recognition and prompt treatment important to minimize permanent loss of function [9]. However, patients with CRPS may still experience permanent impairment and disability despite early recognition and prompt treatment [9]. The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4]. Quantitative sensory testing outcomes indicate altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5].
Epidemiology and Risk Factors: The reported incidence of CRPS is influenced by the choice of diagnostic criteria, study location, and fracture management [15]. The incidence of CRPS following isolated cubital tunnel surgery (CuTS) is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33% [10]. Female sex and the release of more than one digit are significant predictors of developing CRPS following Dupuytren contracture treatment [11]. CRPS-related hand lesions developed in 19.4% of patients following arthroscopic rotator cuff repair (ARCR) [14].
Treatment Modalities: In patients with chronic or refractory CRPS, strong consideration should be given for the use of ketamine [1]. Prednisolone is a potential treatment option for CRPS, particularly in resource-limited settings where specialized interventions may be unavailable [6]. High-intensity laser therapy (HILT) provides conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7]. A more active treatment approach appears to lower the incidence of CRPS-1 [2].
Surgical Outcomes and Specific Contexts: A large percentage of patients diagnosed with and treated for CRPS type 1 can achieve full resolution of symptoms with carpal tunnel release [12]. A patient with bilateral Dupuytren’s contractures developed CRPS-1 after fasciectomy but had a positive outcome with collagenase clostridium histolyticum (CCH) injection and manipulation of the other hand [16]. The methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8]. CRPS is a multifactorial condition requiring further study to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3].
Key Evidence¶
- [L1] In patients presenting with chronic or refractory CRPS, strong consideration should be given for the use of ketamine. (10.1177/15589447221131847)
- [L3] A more active treatment approach seems to lower the incidence of CRPS-1. (10.1177/1558944719895782)
- [L4] CRPS is a multifactorial condition that still requires further studying to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options. (10.1007/s40122-021-00279-4)
- [L4] It can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts. (10.1016/j.jht.2025.02.004)
- [L1] The systematic review and meta-analysis of quantitative sensory testing outcomes indicates altered pain mechanisms in complex regional pain syndrome compared to controls, with a pooled standardized mean difference of -0.41. (10.1186/s13018-022-03461-2)
- [L4] The report emphasizes the importance of recognizing CRPS and highlights the potential of prednisolone as a treatment option, particularly in resource-limited settings where more specialized interventions may be unavailable. (10.1186/s12891-024-07333-0)
- [L1] The study results offer conclusive evidence of pain reduction, a highly debilitating symptom in CRPS-I, even after the third HILT treatment session. (10.1016/j.jht.2025.02.009)
- [L1] Methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor. (10.1177/17589983221138610)
- [L2] CRPS following isolated CuTS is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33%. (10.1016/j.jhsg.2026.101028)
- [L3] Female sex and release of more than one digit are significant predictors of developing CRPS. (10.1177/1558944720963915)
- [L3] This study demonstrates that a large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release. (10.1016/j.jhsa.2024.09.024)
- [L3] The occurrence of CRPS is the result of many factors, with elderly patients, females, and manual laborers having higher risks. (10.1186/s12891-024-07948-3)
- [L3] CRPS-related hand lesions developed in 19.4% of patients following ARCR. (10.5397/cise.2021.00080)
- [L1] The reported incidence of CRPS is influenced by choice of diagnostic criteria, along with the study location and/or how the fracture is managed. (10.1177/1758998320910179)
- [L4] The positive outcome for this woman with Dupuytren's and CRPS-I after CCH injection is encouraging. (10.1016/j.jht.2024.09.002)
- [L3] Preexisting neuropathic disorders, particularly traumatic nerve injuries, compressive neuropathies, and cervical radiculopathy, are the strongest predictors of CRPS after distal radius fracture. (10.1016/j.jhsa.2026.01.004)
- [Case_report] Glomus tumors should be included in the differential diagnosis for patients with unusual chronic pain or neuropathy, and the diagnosis of CRPS should only be a diagnosis of exclusion. (10.1177/1558944719895618)
- [L2] Patients suffering from scaphoid waist fracture may be at a higher risk of CRPS I, especially in women with diabetes mellitus who report severe pain before treatment. (10.1186/s12891-021-04977-0)
References¶
[1] Pharmacologic Treatments in Upper Extremity Complex Regional Pain Syndrome: A Review and Analysis of Quality of Evidence. HAND. 2022. DOI: 10.1177/15589447221131847
[2] Treatment of Distal Radius Fracture: Does Early Activity Postinjury Lead to a Lower Incidence of Complex Regional Pain Syndrome?. HAND. 2020. DOI: 10.1177/1558944719895782
[3] Complex Regional Pain Syndrome: A Comprehensive Review. Pain and Therapy. 2021. DOI: 10.1007/s40122-021-00279-4
[4] Psychometric evaluation of the Hamilton Inventory to evaluate signs and symptoms in patients with Complex Regional Pain Syndrome (CRPS). Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2025.02.004
[5] Pain mechanisms in complex regional pain syndrome: a systematic review and meta-analysis of quantitative sensory testing outcomes. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-022-03461-2
[6] Complex regional pain syndrome: diagnostic challenges and favorable response to prednisolone. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07333-0
[7] Effect of high-intensity laser therapy and mirror therapy on complex regional pain syndrome type I in the hand area: A randomized controlled trial. Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2025.02.009
[8] Person-centred management of upper limb complex regional pain syndrome: an integrative review of non-pharmacological treatment. Hand Therapy. 2023. DOI: 10.1177/17589983221138610
[9] Complex Regional Pain Syndrome. 2021.
[10] Incidence and Patient-Level Risk Factors for Complex Regional Pain Syndrome Following Cubital Tunnel Surgery. Journal of Hand Surgery Global Online. 2026. DOI: 10.1016/j.jhsg.2026.101028
[11] Separating Fact From Fiction: A Nationwide Longitudinal Examination of Complex Regional Pain Syndrome Following Treatment of Dupuytren Contracture. HAND. 2020. DOI: 10.1177/1558944720963915
[12] Outcomes of Median Nerve Release in Complex Regional Pain Syndrome Type 1 of the Hand: A Prospective Case Series. The Journal of Hand Surgery. 2025. DOI: 10.1016/j.jhsa.2024.09.024
[13] Dynamic risk factors for complex regional pain syndrome after distal radius fracture surgery: multivariate analysis and prediction. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07948-3
[14] Clinical outcome in patients with hand lesions associated with complex regional pain syndrome after arthroscopic rotator cuff repair. Clinics in Shoulder and Elbow. 2021. DOI: 10.5397/cise.2021.00080
[15] What is the incidence of complex regional pain syndrome (CRPS) Type I within four months of a wrist fracture in the adult population? A systematic review. Hand Therapy. 2020. DOI: 10.1177/1758998320910179
[16] The case of a woman with bilateral Dupuytren’s contractures who developed CRPS-1 after fasciectomy with no relapse on subsequent collagenase clostridium histolyticum injection and manipulation of the other hand: Considerations for implementing a Budapest criteria checklist and assessing vasomotor instability by measuring differences in skin temperature. Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2024.09.002
[17] A Nationwide Propensity Score-Matched Analysis Identifying Preinjury Predictors of Complex Regional Pain Syndrome Following Distal Radius Fracture. The Journal of Hand Surgery. 2026. DOI: 10.1016/j.jhsa.2026.01.004
[18] An Unusual Case of Periosteal Glomus Tumor at the Metacarpal Base Presenting as Type II CRPS: Case Report. HAND. 2020. DOI: 10.1177/1558944719895618
[19] Determinants of complex regional pain syndrome type I in patients with scaphoid waist fracture- a multicenter prospective observational study. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-021-04977-0