Which preoperative factors, including bone bruise, are associated with knee pain/symptoms at index anterior cruciate ligament reconstruction (ACLR)? A Multicenter Orthopaedic Outcomes Network (MOON) ACLR Cohort Study.
BACKGROUND
Increased knee pain at the time of anterior cruciate ligament reconstruction may potentially predict more difficult rehabilitation, prolonged recovery, and/or be predictive of increased knee pain at 2 years.


OBJECTIVE
A bone bruise and/or other preoperative factors are associated with more knee pain/symptoms at the time of index anterior cruciate ligament reconstruction, and the presence of a bone bruise would be associated with specific demographic and injury-related factors.


METHODS
Cohort study (prevalence); Level of evidence, 2.


METHODS
In 2007, the Multicenter Orthopaedic Outcomes Network (MOON) database began to prospectively collect surgeon-reported magnetic resonance imaging bone bruise status. A multivariable analysis was performed to (1) determine if a bone bruise, among other preoperative factors, is associated with more knee symptoms/pain and (2) examine the association of factors related to bone bruise. To evaluate the association of a bone bruise with knee pain/symptoms, linear multiple regression models were fit using the continuous scores of the Knee injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscales and the Short Form 36 (SF-36) bodily pain subscale as dependent variables. To examine the association between a bone bruise and risk factors, a logistic regression model was used, in which the dependent variable was the presence or absence of a bone bruise.


RESULTS
Baseline data for 525 patients were used for analysis, and a bone bruise was present in 419 (80%). The cohort comprises 58% male patients, with a median age of 23 years. The median Marx activity level was 13. Factors associated with more pain were higher body mass index (P < .0001), female sex (P = .001), lateral collateral ligament injury (P = .012), and older age (P = .038). Factors associated with more symptoms were a concomitant lateral collateral ligament injury (P = .014), higher body mass index (P < .0001), and female sex (P < .0001). Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction. None of the factors included in the SF-36 bodily pain model were found to be significant. After controlling for other baseline factors, the following factors were associated with a bone bruise: younger age (P = .034) and not jumping at the time of injury (P = .006).


CONCLUSIONS
After anterior cruciate ligament injury, risk factors associated with a bone bruise are younger age and not jumping at the time of injury. Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction.
Dunn
Warren R
WR
Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical School, Nashville, TN 37232-8300, USA. warren.dunn@vanderbilt.edu
Spindler
Kurt P
KP
Amendola
Annunziato
A
Andrish
Jack T
JT
Kaeding
Christopher C
CC
Marx
Robert G
RG
McCarty
Eric C
EC
Parker
Richard D
RD
Harrell
Frank E
FE
An
Angel Q
AQ
Wright
Rick W
RW
Brophy
Robert H
RH
Matava
Matthew J
MJ
Flanigan
David C
DC
Huston
Laura J
LJ
Jones
Morgan H
MH
Wolcott
Michelle L
ML
Vidal
Armando F
AF
Wolf
Brian R
BR
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001842:Bone and Bones / Q000293:injuries; D002358:Cartilage, Articular / Q000293:injuries; D015331:Cohort Studies; D003288:Contusions / Q000150:complications; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000473:pathology* / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery*; D016014:Linear Models; D008297:Male; D049451:Nomograms; D019637:Orthopedic Procedures; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement; D057234:Preoperative Period; D012307:Risk Factors; D055815:Young Adult