title: Short-term effects of discoid lateral meniscectomy on the axial alignment of the lower limb in adolescents.
abstract: BACKGROUND
  A discoid lateral meniscus in the knee is more common in Asian populations. The aim of this study was to evaluate the influence of arthroscopic meniscectomy of the discoid lateral meniscus on the axial alignment of the lower limb in adolescents (younger than twenty years of age).
  
  
  METHODS
  We retrospectively reviewed the data from 298 adolescent patients (younger than twenty years of age) who underwent arthroscopic treatment in our center from 2004 to 2013. Patients were divided into three groups according to the meniscus type: torn discoid lateral meniscus (Group A), torn nondiscoid lateral meniscus (Group B), and nondiscoid lateral meniscus without a tear (Group C). The tibiofemoral angle (TFA) and mechanical axis deviation (MAD) of both lower limbs were examined on standing anteroposterior radiographs before and after arthroscopy.
  
  
  RESULTS
  The preoperative TFA and MAD of the ipsilateral lower limbs demonstrated significantly more varus in Group A than in Group B (p < 0.001) or Group C (p < 0.001) after we controlled for the contralateral lower limbs as a covariate factor. Moreover, the TFA and MAD of the ipsilateral knees were significantly reduced (indicating a reduction in varus inclination) postoperatively, as compared with preoperatively, in Group A (p < 0.001) and Group B (p < 0.001), with no difference between the preoperative and postoperative values in Group C (p > 0.01), after we controlled for the contralateral lower limb as the covariate factor. Additionally, the reductions in the TFA and MAD (varus inclination) in Group A were significantly greater than those observed in Group B (p < 0.001).
  
  
  CONCLUSIONS
  The axial alignment of the lower limb in adolescents (younger than twenty years of age) with a torn discoid lateral meniscus was altered immediately after arthroscopic meniscectomy: the varus deformity was significantly reduced, and a valgus inclination developed in some of these patients. The valgus inclination was more pronounced in the patients with a torn discoid lateral meniscus compared with those with a torn nondiscoid lateral meniscus.
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Junfei
authors: J
authors: Wang
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Jin
authors: J
authors: Xiong
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Zhihong
authors: Z
authors: Xu
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Hongfei
authors: H
authors: Shi
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Jin
authors: J
authors: Dai
authors: Department of Orthopedics (J.W., J.X., and H.S.) and The Center for Diagnosis and Treatment of Joint Disease (Z.X., J.D., and Q.J.), Nanjing Drum Tower Hospital, the affiliated hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008, China. E-mail address for Q. Jiang: jiangqing112@hotmail.com.
authors: Qing
authors: Q
authors: Jiang
mesh_terms: D000293:Adolescent; D001182:Arthroscopy; D017760:Bone Malalignment / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D035002:Lower Extremity / Q000000981:diagnostic imaging*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D000070600:Tibial Meniscus Injuries