Retrospective Eight Plate Study
Condition: Leg Length Discrepancy; Varus/Valgus Deformities of the Knee
MeSH terms: Leg Length Inequality; Congenital Abnormalities
Study type: Observational

Summary: 
      Understanding bone growth and achieving bone deformity corrections re-mains one of the oldest
      challenges in paediatric orthopaedics.

      The purpose of this study is to investigate the clinical and biomechanical effects of
      implants for growth modulation in pediatric patients undergoing correction of leg length or
      deformities of the knee.

      The primary aim of the study is to assess outcome after growth modulation using the Eight
      plate (Orthofix) at the time of implant removal with regard to any Adverse Events (AE)
      related to the growth plates or implants under investigation. The secondary aims are to
      assess if the planned correction was achieved and if the achieved correction was maintained
      after implant removal. Furthermore, secondary aims include investigation of the number and
      type of revision surgeries, the proportions of any other local AE as well as any influencing
      factors for growth modulation.
    

Detailed description: 
      One of the oldest mysteries in paediatric orthopaedics is the knowledge about bone growth and
      the ability to correct acquired bone deformities. Guiding the growth of a bone for deformity
      cor-rection by harnessing the ability of a growing bone to undergo plastic deformity is a
      well-known pediatric orthopaedic principle. Nevertheless, there are still many open questions
      concerning growth and guided growth. Several surgical options already exist for correction of
      angular de-formity and leg length discrepancies. The gold standard remains the corrective
      osteo¬tomy before or after growth arrest.

      Correction during growth poses the risk of recurrence of the deformity during growth. By any
      means, growth modulation involves major surgery and requires internal or external fixation.
      Epiphysiodesis or hemiepiphysiodesis, either permanent or temporarily, can be done in an open
      or percutaneous way. Permanent epiphysiodesis is mainly performed using screws, while for a
      temporary epiphysiodesis staples or plate/screw systems are used. The treatment seems to be
      clinically effective, but the precise calculation of the remaining growth and the optimal
      surgical timing are crucial. Furthermore, the underlying biomechanical properties are not yet
      fully known.

      The objective of this study is to investigate the clinical effects of the Eight Plate system
      for growth modulation treatments in pediatric patients undergoing leg length corrections or
      deformity corrections of the knee. The primary aim of the study is to assess outcome of
      growth modulation at removal of the implants with regards to AEs related to the growth plates
      or implants under investigation. The secondary aims are to assess if the planned correction
      was achieved and if the achieved correction was maintained after Eight Plate removal.
      Furthermore, secondary aims include the investigation of the number and type of revision
      surgeries, any functional deficits after implant removal, any additional local AE, the
      assessment of the primary implant positioning, and any additional radiological parameters
      related to the implants and leg alignment.
    

Observational model: Case-Only
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Pediatric patients with an age range at implantation of the Eight Plate growth modulation
        devices of 18 months to 17 years

        Treatment with Eight Plate (Orthofix) of varus/valgus deformities of the knee and/or leg
        length discrepancy due to any of the following:

          -  Diseases or syndromes affecting the growth plate (eg, Blount's dis-ease)

          -  Post-traumatic, affecting the growth plate

          -  Post-infectious, affecting the growth plate

          -  Idiopathic etiology
      
Keywords: Growth modulation; Eight plate; Leg length discrepancy; Varus/valgus deformities; Pediatric