title: Anterior knee symptoms after double-bundle ACL reconstruction with hamstring tendon autografts: an ultrasonographic and power Doppler investigation.
abstract: OBJECTIVE
  Anterior knee pain related to the donor site is a frequent complication of anterior cruciate ligament reconstruction (ACLR) with bone-patellar tendon-bone autograft tissue. Even when hamstring tendon (HT) grafts are used instead, symptoms such as mild pain and discomfort can still occur. The purpose of this study was to elucidate the pathophysiology of anterior knee symptoms after ACLR with HT autografts.
  
  
  METHODS
  Fifty-seven patients (22 men and 35 women; mean age, 24.7 years) who underwent anatomic double-bundle ACLR with HT autografts were examined 6 months post-operatively. The presence of anterior knee symptoms, anterior knee laxity, range of motion, and muscle strength were assessed. Changes in patellar tendon and infrapatellar fat pad (IFP) morphology and blood flow were also evaluated using ultrasound. Potential variables affecting the presence of anterior knee symptoms were subjected to univariate analysis and multivariate logistic regression analysis to identify independent risk factors.
  
  
  RESULTS
  Six months post-operatively, the total incidence of anterior knee symptoms was 56.1 % (32/57). According to univariate analysis, age, quadriceps strength, and increased blood flow in the IFP were significantly associated with the presence of anterior knee symptoms. Multivariate logistic regression analysis revealed that increased blood flow in the IFP was an independent factor for the presence of anterior knee symptoms (odds ratio 5.0; 95 % confidence interval 1.3-19.9). There were no significant findings inside the patellar tendon.
  
  
  CONCLUSIONS
  Increased blood flow in the IFP was identified as an independent factor for the presence of anterior knee symptoms 6 months after ACLR with HT autografts. The ultrasound evaluation can help to define precisely the origin of anterior knee symptoms after ACLR with HT autografts.
  
  
  METHODS
  Case series with no comparison groups, Level IV.
authors: Department of Rehabilitation, Osaka Rosai Hospital, 1179-3, Nagasone-cho, Kita-ku, Sakai, Osaka, 597-8025, Japan. takanamoto2@gmail.com.
authors: Takashi
authors: T
authors: Kanamoto
authors: Department of Orthopaedic Surgery, Osaka Rosai Hospital, Sakai, Japan.
authors: Yoshinari
authors: Y
authors: Tanaka
authors: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka University, Osaka, Japan.
authors: Yasukazu
authors: Y
authors: Yonetani
authors: Department of Orthopaedic Surgery, Osaka Rosai Hospital, Sakai, Japan.
authors: Keisuke
authors: K
authors: Kita
authors: Department of Orthopaedic Surgery, Osaka Rosai Hospital, Sakai, Japan.
authors: Hiroshi
authors: H
authors: Amano
authors: Department of Orthopaedic Surgery, Kansai Rosai Hospital, Sakai, Japan.
authors: Masashi
authors: M
authors: Kusano
authors: Department of Rehabilitation, Osaka Rosai Hospital, 1179-3, Nagasone-cho, Kita-ku, Sakai, Osaka, 597-8025, Japan.
authors: Shinji
authors: S
authors: Hirabayashi
authors: Faculty of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan.
authors: Shuji
authors: S
authors: Horibe
mesh_terms: D000273:Adipose Tissue / Q000098:blood supply / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D018771:Arthralgia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D064592:Autografts / Q000637:transplantation; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology; D007717:Knee / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D007719:Knee Joint / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D017847:Patellar Ligament / Q000098:blood supply / Q000000981:diagnostic imaging; D052097:Quadriceps Muscle / Q000637:transplantation; D016059:Range of Motion, Articular; D012039:Regional Blood Flow; D012307:Risk Factors; D013710:Tendons / Q000637:transplantation*; D014182:Transplantation, Autologous; D014463:Ultrasonography; D055815:Young Adult
keywords: ACL reconstruction; Anterior knee problems/symptoms; Increased blood flow; Infrapatellar fat pad; Ultrasound