title: Knee Laxity Variations in the Menstrual Cycle in Female Athletes Referred to the Orthopedic Clinic.
abstract: BACKGROUND
  Anterior cruciate ligament (ACL) rupture is the biggest concern for orthopedic surgeons who are involved in sports injuries, so most of ACL reconstruction surgeries are sports related. ACL injuries in female athletes are 2 - 8 times more common than male athletes in similar sport injuries.
  
  
  OBJECTIVE
  The aim of this study was to compare knee laxity changes in the menstrual cycle in female athletes referred to the orthopedic clinic of Imam Khomeini hospital in the north of Iran, Sari, 2013.
  
  
  METHODS
  The present descriptive study was conducted on 40 female athletes that were referred to the orthopedic clinic. Hormone levels, such as estrogen and progesterone were assessed by one laboratory in 3 phases of the menstrual cycle. We used Lachman test and anterior drawer test for knee laxity rate. The descriptive statistics were calculated as indices of central distribution of bonds (x ± SD) and relative frequency distribution was used for qualitative variables.
  
  
  RESULTS
  The results of the current study showed that there is no significant difference in ACL laxity in female athletes in three phases of menstrual cycle; namely menstruation time, ovulation time and mid-luteal phase.
  
  
  CONCLUSIONS
  Despite numerous studies and research in the field of knee laxity and effects of female hormones, many researchers do not agree about the effect of female hormones on knee laxity. The current study also reported no relationship between female hormones and knee laxity, while statistics show fundamental difference between male and female athletes.
authors.affiliation: Department of Orthopedic, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Seyed Esmaeel
authors.initials: SE
authors.lastname: Shafiei
authors.affiliation: Department of Gynecology and Obstetrics, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Peyvandi
authors.affiliation: Department of Orthopedic, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Mohamad Hosein
authors.initials: MH
authors.lastname: Kariminasab
authors.affiliation: Department of Orthopedic, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Shayesteh Azar
authors.affiliation: Department of Orthopedic, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Seyed Mohamad Mehdi
authors.initials: SM
authors.lastname: Daneshpoor
authors.affiliation: Department of Biostatistics, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Khalilian
authors.affiliation: Department of Medecine, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Aghajantabar
keywords: Athletes; Joint laxity; Knee; Menstrual Cycle