Diagnosis, Management, and Treatment of Complex Regional Pain Syndrome after Total Knee Arthroplasty: A Systematic Review and Qualitative Assessment
Bibliographic record
Abstract
Objective: To determine the incidence, presentation, and management of complex regional pain syndrome (CRPS) after total knee arthroplasty (TKA). Literature Survey: A Preferred Reporting Items for Systematic Reviews (PRISMA) compliant search was performed in February 2025 using PubMed, Embase, Ovid/MEDLINE, and Cochrane Central Register of Controlled Clinical Trials to identify TKA studies that describe CRPS. Case reports and non-English articles were included. Methodology: Two independent reviewers screened studies using specific eligibility criteria. Study characteristics, incidence, symptoms, physical exam findings, diagnostic modalities, therapies, and outcomes were extracted. Studies were evaluated according to the Newcastle-Ottawa scale and adherence to CARE case report guidelines. Synthesis: Fifteen studies comprising 125 TKA patients diagnosed with CRPS were included. The mean age was 64 7 years, 67.7% of patients were female, and mean follow-up was 16.9 15.9 months. The incidence of CRPS after TKA was 2.8% (83/2945). Mean time from surgery to diagnosis was 7 3.4 months (n=86). The most prevalent findings were edema (72.5%, 29/40), knee stiffness (62.5%, 25/40), hyperalgesia (62%, 43/69), allodynia (59%, 41/69), and skin temperature changes (50%, 20/40). Therapeutic sympathetic blocks were used in 75% (36/48) of cases, of which 42% (15/36) of patients had persistent symptoms after treatment. Manipulation under anesthesia was performed in 25% (n=11) of cases and resulted in an average increase in flexion of 29 (n=6). The average ROM at diagnosis was 3.4° - 66.1° (n=16) compared to 3.3° - 92.2° (n=12) at final follow-up. Conclusions: The archetypical CRPS TKA patient presents with disproportionate and unexplainable knee pain nine months postoperatively, often with burning and altered sensation, stiffness, edema, and temperature asymmetry on exam. Reported incidence varies significantly, likely due to evolving diagnostic criteria and a historical tendency to ascribe unexplainable pain to CRPS. However, the condition may be underdiagnosed after TKA given the multiple risk factors and prevalence of chronic unexplainable pain associated with knee replacement.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.036 | 0.107 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.007 | 0.007 |
| Bibliometrics | 0.016 | 0.015 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".