Transphyseal Vs. Physeal Sparing ACL Reconstruction in Skeletally Immature Patients: Risk of Subsequent Lower Extremity Growth Deformity
Condition: ACL Reconstruction
MeSH terms: Congenital Abnormalities
Study type: Observational

Summary: 
      To assess the risk of lower extremity angular growth deformity following anterior cruciate
      ligament (ACL) reconstructions in young patients who are not yet skeletally mature. The study
      will compare two surgical techniques (physeal sparing vs transphyseal).
    

Detailed description: 
      Background & Significance: In the adult population, the vast majority of ACL reconstructions
      are performed by drilling femoral and tibial bone tunnels. Because these patients have
      achieved physeal closure by the time of surgery, there is no risk of angular growth deformity
      when creating tibial and femoral tunnels. However, in the pediatric patient with open tibial
      and femoral physes, there is concern that drilling across the physes using standard tunnels
      may cause physeal injury with resultant angular deformity. Other surgical techniques have
      been described that allow the graft to be placed without drilling tunnels across the tibial
      and femoral physes but there is debate regarding whether or not these "physeal sparing"
      techniques are as effective as the transphyseal tunnel positions. Drilling the tunnels in the
      epiphysis to avoid the physis is a common "physeal sparing" technique. It is debated whether
      this technique could also cause growth disturbances. Given the increasing number of pediatric
      ACL injuries and that 95% of patients age 12 or less have open physes and that 94% of
      patients age 14 or greater have closed physes, this topic is of significant interest. Similar
      studies have been conducted but most have been either small and underpowered or have included
      older adolescent patients. At Duke Sports Sciences Institute, we have a sizable population of
      patients age 16 or less who have undergone ACL reconstruction with both transphyseal and all
      epiphyseal techniques. This provides a unique opportunity to analyze and compare these two
      groups with respect to clinical outcome and the incidence of growth disturbance or angular
      deformity

      Design & Procedures: The investigator will conduct a review of medical records of seven
      providers at a single site institution to determine the subject population. Specifically, the
      investigator will look for patients who had an ACL reconstruction between the ages of 6-16
      after January 1, 2005. The investigator will confirm in the medical record and in
      pre-operative radiographs that the growth plates were open at the time of surgery. Only
      subjects with open physeal will be enrolled in the study and they will be placed in 3
      cohorts: Ages less than 12, 12-13, and 14 - 16. Subjects will be contacted by phone by a
      member of the team and asked to return to Duke Sports Sciences Institute to participate in
      the study. Upon arrival to clinic, subjects will be consented for the study and undergo a
      full physical exam - specifically targeting the gait and range of motion, as well as the
      Lachman, Anterior Drawer and Pivot Shift maneuvers to assess stability and functionality of
      the graft. In addition, they will complete a questionnaire designed to elicit patient
      satisfaction and level of activity/sports participation after the initial recovery period.
      Bilateral hip to ankle radiographs will be taken of each subject. These radiographs will be
      analyzed to assess for any angular deformity between the surgical and non-surgical leg. In
      addition, baseline knee x-rays will be reviewed for determination of skeletal maturity at
      time of injury/surgery. Data will be organized according to patients who underwent
      transphyseal reconstruction and patients who underwent physeal sparing reconstruction and
      separated into the corresponding age group. Comparisons will be made between the two surgical
      techniques based on the following criteria:

        -  Patient satisfaction and return to function

        -  Graft stability

        -  Angular deformity

        -  Skeletal maturity at the time of surgery

      Study Interventions: Subjects will undergo physical examination (gait, inspections, range of
      motion and instability testing) and completion of an outcome tool survey (IKDC
      score/PediIKDC, VAS, Marx, and ACL-RSIsurvey). Subjects will undergo bilateral hip to ankle
      radiographic imaging to assess for growth deformity. Subjects will also be asked to give
      their permission to review their medical record and imaging pertinent to the knees and knee
      surgery.

      Data Analysis & Statistical Considerations: Patient's data will be collected in a database
      program, indexed initially by medical record number. After case collection, case numbers will
      be applied and medical record numbers stripped from the data. The code linking medical record
      number to case number will be kept in a locked file with access limited to primary
      investigator.

      Contingency analysis using the Fisher exact test will be used to compare the distribution of
      normal/nearly normal exam findings between the three cohorts

      Descriptive statistics (mean, standard deviation and range) will be reported for each of
      these scores

      Scores will be compared between the three cohorts using ANOVA with post-hoc analysis using
      Tukey's correction for multiple comparisons

      Privacy, Data Storage & Confidentiality: The primary investigator will collect data in a
      computerized database using a commercially available database program. During collection,
      data will be indexed by the patient's medical record number. After data collection, a case
      number will be assigned to the data and the medical record number (the only identifying data
      collected) will be stripped from the database. The code linking medical record number to case
      number will be kept in a locked file with access limited to primary investigator. When the
      study is complete the code linking medical record numbers to case numbers will be destroyed.
      During data collection and review, protected health information will be available only to the
      primary investigator and will not be reused or disclosed to any other person or entity,
      except as required by law, for authorized oversight of the research study.
    

Intervention name(s): Bilateral hip to ankle x-ray, exam and strength testing.
Intervention type(s): Diagnostic Test
Intervention description(s): Only an X-Ray is performed and reviewed to identify any growth disturbances.
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Single site patients of five orthopaedic sports medicine attendings who had an ACL
        reconstruction between the ages of 6-16 with open physes in the time interval from January
        1, 2005-December 31, 2016.
      
Keywords: surgery; ages 6-16