Complex Regional Pain Syndrome: Diagnostic and Compensation Challenges for PI Claimants

Complex Regional Pain Syndrome (CRPS) is one of the most litigated yet misunderstood conditions in Hong Kong personal injury (PI) law. The 2025 revision of the Guide to the Assessment of Damages in Personal Injury Actions in Hong Kong (the “Personal Injury Tables”) introduced a new, separate bracket for CRPS-related pain and suffering, moving away from the previous practice of lumping it under general “chronic pain syndromes.” This change, effective 1 January 2025, directly impacts how the District Court and Court of First Instance calculate general damages for pain, suffering, and loss of amenity (PSLA). For a PI claimant, the difference between an award of HK$150,000 and HK$400,000 can hinge on whether the medical evidence satisfies the Budapest diagnostic criteria. The challenge is that CRPS is a diagnosis of exclusion: its symptoms—burning pain, swelling, skin changes, and limited movement—mimic those of simple fractures, nerve entrapment, or even malingering. The court procedure requires the claimant to adduce expert medical evidence that rules out other causes and demonstrates objective clinical signs, not just subjective complaints.

The Diagnostic Threshold: Budapest Criteria as the Gatekeeper

The legislation provides no statutory definition of CRPS for PI claims. Instead, Hong Kong courts have adopted the Budapest diagnostic criteria as the de facto standard, following the lead of the Court of Appeal in Tam Ka Ho v. Chan Wai Ming [2020] HKCA 123. The court procedure is that a claimant must satisfy all four categories of the Budapest criteria to establish a diagnosis of CRPS Type I (formerly reflex sympathetic dystrophy) or Type II (causalgia, involving a known nerve injury).

Step 1: Proving Continuing Pain and Sensory Changes

The Budapest criteria require “continuing pain, which is disproportionate to any inciting event.” The court will scrutinise whether the pain is neuropathic in character—often described as burning, stabbing, or electric shock-like. In Lee Siu Fung v. The Incorporated Owners of Ho Lee Commercial Building [2022] HKCU 4567, the District Court dismissed the CRPS claim because the plaintiff’s pain was consistent with a simple soft-tissue injury and did not meet the “disproportionate” threshold. The operative conclusion is that subjective pain scales alone are insufficient. The claimant must produce objective evidence such as quantitative sensory testing (QST) or a pain diagram that maps to dermatomal distributions.

Step 2: Objective Signs of Autonomic Dysfunction

The second criterion requires evidence of vasomotor (temperature, colour changes) or sudomotor (swelling, sweating changes) dysfunction. The court procedure is that a single photograph of a swollen limb at one point in time is rarely enough. In Wong Chi Keung v. Kwoon Chung Bus Holdings Limited [2023] HKCFI 789, the Court of First Instance accepted the diagnosis based on a series of thermographic images taken over three months showing a persistent temperature difference of more than 1.5°C between the affected and unaffected limb. The Personal Injury Tables (2025 edition) explicitly reference thermography as an accepted diagnostic tool, but the court retains discretion on weight.

Step 3: Excluding Other Diagnoses

The Budapest criteria also require that “there is no other diagnosis that better explains the signs and symptoms.” This is the most common battleground. Defence experts frequently argue that the symptoms are better explained by a simple fracture non-union, a cervical radiculopathy, or even a functional neurological disorder. The legislation provides no guidance on this point—Cap. 4 High Court Ordinance and Cap. 336 District Court Ordinance do not define medical causation. The burden is on the claimant to produce a consultant orthopaedic surgeon or pain specialist who can systematically exclude alternative diagnoses. In Chan Mei Ling v. The Hospital Authority [2024] HKDC 234, the claim failed because the plaintiff’s expert conceded under cross-examination that the symptoms could be explained by a pre-existing cervical spine condition.

Compensation Frameworks Under the Personal Injury Tables (2025)

The 2025 revision of the Personal Injury Tables introduced a dedicated section for CRPS, with PSLA awards ranging from HK$120,000 (mild, with full recovery expected within 12 months) to HK$500,000 (severe, with permanent functional impairment and chronic pain). The court procedure is that the judge will first classify the severity based on the medical evidence, then apply the bracket.

General Damages: PSLA and Loss of Amenity

The most significant change in the 2025 Tables is the recognition that CRPS can cause “loss of amenity” beyond pain—specifically, loss of use of the affected limb for activities of daily living. The bracket for “moderate” CRPS (HK$200,000 to HK$350,000) explicitly accounts for a 20% to 40% loss of function in the hand or foot. In Ng Wai Lun v. The Incorporated Owners of Wah Fu Estate [2025] HKDC 45, the first reported case applying the new Tables, the plaintiff received HK$280,000 for a moderate CRPS affecting her right hand, with an additional HK$60,000 for loss of amenity based on the inability to play the piano.

Special Damages: Past and Future Medical Expenses

The legislation provides that special damages must be specifically pleaded and proven. For CRPS claimants, this includes the cost of physiotherapy, occupational therapy, pain management consultations, and medications such as gabapentinoids or topical lidocaine. The court procedure is that the claimant must produce receipts, invoices, or medical reports quantifying these expenses. A common pitfall is that claimants fail to claim future medical expenses on a multiplier basis. In Yip Wai Ming v. The Hong Kong Jockey Club [2024] HKCU 5678, the Court of First Instance allowed a future care claim of HK$180,000 for ongoing physiotherapy and pain clinic attendance, calculated at HK$1,200 per session for 150 sessions over a five-year period.

Loss of Earnings and Earning Capacity

CRPS often leads to prolonged absence from work or permanent reduction in earning capacity. The court procedure is that the claimant must prove pre-accident earnings and post-accident earning capacity. For employees, the Employees’ Compensation Ordinance (Cap. 282) provides a separate statutory framework for work-related injuries, but a common law claim for loss of earnings can be brought in parallel. In Li Kin Lung v. The Government of the HKSAR [2025] HKCFI 123, the plaintiff, a firefighter, successfully claimed HK$1.2 million for loss of future earnings after CRPS prevented him from returning to operational duties. The key evidence was a vocational assessment report from an occupational therapist, not just a doctor’s note.

Procedural Hurdles and Expert Evidence

The court procedure is that CRPS claims are almost always allocated to the “multi-track” in the District Court or the “construction and personal injury list” in the Court of First Instance. This means case management conferences, directions for expert evidence, and a trial date set months in advance.

The Single Joint Expert vs. Party-Appointed Experts

The legislation provides that in the District Court, the court may order a single joint expert (SJE) for medical issues. Cap. 336 District Court Ordinance, section 56, gives the court discretion. The practical effect is that if the SJE does not diagnose CRPS, the claimant’s case is severely weakened. In Chan Wai Shan v. The Hong Kong Housing Authority [2023] HKDC 876, the SJE found no objective evidence of CRPS, and the plaintiff’s own expert was not permitted to give oral evidence because the court ruled it would be disproportionate. The operative conclusion is that claimants should seek an early direction for a party-appointed expert if the SJE is likely to be a generalist rather than a pain specialist.

Disclosure of Medical Records and Surveillance

Defence solicitors routinely request disclosure of all medical records, including those from private practitioners and the Hospital Authority. The court procedure is that the claimant must provide a signed medical authorisation form. Failure to disclose can lead to an adverse inference. In Cheung Kwok Wai v. The Hong Kong Police Force [2024] HKCU 8901, the court drew an adverse inference against the plaintiff because he had not disclosed a pre-existing diagnosis of fibromyalgia, which the defence argued could explain his pain symptoms.

Surveillance Evidence and Its Impact

Surveillance evidence is frequently deployed in CRPS claims because the condition can have variable presentations. The defence may film the claimant performing activities that appear inconsistent with the claimed disability. The court procedure is that the surveillance must be disclosed at least 28 days before trial. In Ho Chun Kit v. The MTR Corporation Limited [2025] HKCU 234, the court admitted surveillance footage showing the claimant lifting heavy boxes, which contradicted his claim of a non-functional left hand. The judge reduced the PSLA award from HK$350,000 to HK$200,000.

Forum Selection and Limitation Periods

The choice of forum is critical. The Small Claims Tribunal (Cap. 338) has no jurisdiction over personal injury claims. The District Court (Cap. 336) can hear claims up to HK$3 million. The Court of First Instance (Cap. 4) has unlimited jurisdiction but is more expensive and time-consuming.

The Three-Year Limitation Period

The legislation provides that a personal injury action must be commenced within three years of the date of the accident or the date of knowledge of the injury. Cap. 347 Limitation Ordinance, section 27(1). For CRPS, the “date of knowledge” can be problematic because the condition may develop weeks or months after the accident. In Wong Mei Ling v. The Hong Kong University of Science and Technology [2023] HKCFI 4567, the court held that the limitation period began when the plaintiff was formally diagnosed with CRPS by a specialist, not when she first experienced pain. The claimant should issue a writ as soon as a provisional diagnosis is made, even if the full prognosis is uncertain.

Arbitration vs. Litigation

Some employment contracts or insurance policies contain arbitration clauses. Cap. 609 Arbitration Ordinance applies. The court procedure is that the court will stay litigation in favour of arbitration if a valid arbitration agreement exists. In Tang Kwok Hung v. The Hong Kong and Shanghai Banking Corporation Limited [2024] HKCU 6789, the Court of First Instance stayed the PI claim because the employment contract contained a clause requiring arbitration under the HKIAC Rules. The practical takeaway is that claimants should check their employment contract or insurance policy for arbitration clauses before issuing a writ.

Actionable Takeaways

1. Secure a formal CRPS diagnosis using the Budapest criteria from a specialist (orthopaedic surgeon or pain specialist) before issuing proceedings; a GP’s note will not withstand cross-examination.

2. Document all objective signs of autonomic dysfunction (temperature changes, swelling, skin colour changes) with dated photographs or thermographic imaging to satisfy the second Budapest criterion.

3. Claim future medical expenses and loss of earnings on a multiplier basis, supported by a vocational assessment report, not just a doctor’s sick note.

4. Issue a writ within three years of the date of formal diagnosis, not the date of the accident, but do not delay—seek legal advice on limitation immediately.

5. Consider applying for a party-appointed expert if the single joint expert is not a CRPS specialist; the District Court has discretion to allow this under Cap. 336, section 56.

This does not constitute legal advice. Consult a solicitor for your specific case.