Incidence and risk factors of loss of motion following anterior cruciate ligament reconstruction: a systematic review and meta-analysis
Bibliographic record
Abstract
IMPORTANCE: The anterior cruciate ligament (ACL) is the most commonly injured ligament of the knee, with most patients undergoing surgical reconstruction. Of these patients, 6.5-27.6% require a second operation to treat loss of motion, which can cause substantial delays in patient recovery and return to sport. Currently, there is a paucity of comprehensive data regarding loss of motion following anterior cruciate ligament reconstruction (ACLR) surgery, resulting in variable measures of incidence and uncertainty about risk factors. OBJECTIVE: The primary objective of this study is to identify the incidence and risk factors for repeat surgical intervention for loss of motion following primary ACLR. EVIDENCE REVIEW: Two independent reviewers conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The EMBASE, MEDLINE, and PubMed databases were searched, along with the reference lists of included articles and related systematic reviews. Studies were included if they met the following criteria: (1) included adult patients with primary ACL ruptures treated surgically, (2) had a follow-up period of at least 3 months postoperative, (3) provided an objective definition of stiffness, arthrofibrosis, or cyclops lesions, and (4) reported the incidence and/or risk factors for loss of motion. A random-effects meta-analysis was conducted to estimate the pooled incidence of loss of motion across studies. FINDINGS: A total of 48 studies were included in the final analysis. Of these studies, 46 reported the incidence of loss of motion requiring surgery, with a mean pooled incidence of 4% (95% CI: 3-5 %). The incidence decreased over time from 10% (95% CI: 7-13%) in 1991-1999 to 4% (95% CI: 3-5%) in 2000-2023. There were 29 studies that reported statistically significant risk factors for loss of motion requiring surgery. The most common risk factors were female sex, acute repair, concomitant meniscus repair, delayed postoperative range of motion, and preoperative range of motion deficit. CONCLUSION: The incidence of loss of motion requiring surgery after ACLR is 4%, with a variety of risk factors related to the patient, injury, surgery, and recovery. The incidence has decreased over time, but arthrofibrosis remains a devastating surgical complication that is important to discuss with patients. LEVEL OF EVIDENCE: III.
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 | 0.017 | 0.047 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.018 | 0.042 |
| Bibliometrics | 0.007 | 0.009 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 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".