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Hinged Versus Conventional 8 Plate for Correction of Genu Valgum or Varum

Not Applicable
Conditions
Genu Valgum or Varum
Growth; Arrested, Bone
Epiphyseal Arrest, Lower Leg
Interventions
Device: hinged 8-figure plate
Device: conventional 8-figure plate
Registration Number
NCT03378206
Lead Sponsor
Xinhua Hospital, Shanghai Jiao Tong University School of Medicine
Brief Summary

To assess the therapeutic effect of hinged 8-figure plate by comparing with the traditional 8-figure plate through a randomized controlled clinical trial by assessing the differences between preoperative and postoperative data.

The hypothesis is that the hinged 8 plate provides low complications that this treatment is as good as the traditional one.

Detailed Description

Angular deformities of the lower limb is major clinical problems encountered in pediatric orthopedics. Deformities can be either valgus or varus and most commonly affect the knee joint, which may result in patella dislocation, gait instability and serious impact on the appearance and function of the lower limbs. Biomechanical studies and gait analysis found that genu varus increased medial articular surface pressure of the knee, while genu valgus increased lateral articular surface pressure, and both of them are the risk factors for osteoarthritis. Surgical treatment techniques include osteotomy and hemiepipysidesis. Osteotomy surgery is the gold standard for severe angular deformity or epiphyseal closed patients, but it was associated with lots of complications, including osteofascial compartment syndrome, neurovascular injury, deep soft tissue infection, nonunion and requiring a long recovery time. While, for patients whose epiphyseal is not closed, the traditional 8 plate hemiepipysidesis has fewer complications. However, it showed some problems in clinical applications, such as steel plate or screw broken. The investigators designed a new hinged 8 plate, which has two arms and a built-in hinge. Based on the previous studies, investigators designed the rotation of the two arms ranged from 155° to 170° to better fit the contour of the physis in all stages of angular correction. That automatic change can also disperse repeated stress on the surface of periosteum and perichondrium during walking. The plate had been tested on animal models that the use of the hinged plate and screw system may be a more reliable technique with minimal complications for correction of angular deformities of the lower limb.

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
80
Inclusion Criteria
  1. Idiopathic genu valgus or varum
  2. Without any treatment
  3. lower limb mechanical axis over the tibial plateau in the range of 1/2;
  4. Epiphyseal not yet closed, with more than 12 months of growth potential
Exclusion Criteria
  1. Physiological genu valgus or varum
  2. Epiphyseal have closed or no growth potential
  3. Pathological limb deformity(Blount disease, inflammation,trauma)
  4. Other causes of lower limb angular deformity.
  5. With surgical contraindications

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Hinged 8-figure platehinged 8-figure plateHinged 8-figure plate is a novel devise that has modifications in order to improve the treatment effect of conventional 8-figure plate. This arm will be used to verify the effectiveness and feasibility of the modification.
conventional 8-figure plateconventional 8-figure plateConventional 8-figure plate is widespread method to treat genu varum and valgus. This arm, as a comparator, will be the control group to verify the feasibility of the novel hinged 8-figure plate.
Primary Outcome Measures
NameTimeMethod
The complications.2 years

Surgery related complications including osteofascial compartment syndrome, neurovascular injury, deep soft tissue infection and so on will be observed until correction of deformity.

Secondary Outcome Measures
NameTimeMethod
The corrective rates of medial slope angle.2 years

The angle of medial slope will be measured when reexamination until the correction of deformity, which was used to calculate the corrective rates.

The corrective of Mechanical lateral distal femoral angle.2 years

The corrective of Mechanical lateral distal femoral angle will be measured when reexamination until the correction of deformity. And investigators will calculating the change of this angle.

The movement of two arms of the hinged plate.2 years

The movement of two arms during the experiment will be noted by the changing of two arms angle when reexamination until the correction of deformity.

The residual stress on the implants.2 years

Residual stress (remaining stress of the sample after implant removal) at the rim of the metaphyseal screw hole will be measured using X-ray diffraction.

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