Orthopedic device and method for correcting angular bone deformity

Abstract

An orthopedic device and method for correcting angular deformation of a bone structure having a growth plate. The device includes first and second hinge members connected together at a hinge joint. The device is adapted for mounting the orthopedic device to the bone structure with the pivot joint positioned over the growth plate. Alignment of the pivot joint with the growth plate promotes asymmetric growth of the growth plate to thereby correct the angular deformation.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates to correcting angular bone deformities, and more particularly to an orthopedic device and method for correcting angular deformities of the lower extremities, such as genu varus and genu valgus conditions. [0002] Angular bone deformities of the lower extremities are typically characterized by abnormal angulations of the lower leg in relation to the thigh. For example, genu varum is characterized by an abnormal outward bowing of the leg resulting in bowlegs, while genu valgum is characterized by an inward bowing of the leg and is commonly referred to as knock-knees. Under normal conditions, the femur and tibia meet at a tibial-femoral angle of approximately 5-12 degrees of valgus. A greater angle results in a genu valgus condition while a lesser angle results in a genu varum condition. Either of these conditions in one or both legs may result in improper load distribution on the knee joint, causing swelling, knee pain, loss of ...

AI Technical Summary

Benefits of technology

[0010] One aspect of the present invention provides an orthopedic device for correcting angular deformation of a bone structure having a first bone portion separated from a second bone portion by a growth plate. The orthopedic device includes first and second hinge members that are pivotally connected together at a pivot joint. The first hinge member is adapted for connection to the first bone portion and the second hinge member is adapted for connection to the second bone portion. Alignment of the pivot joint with the growth plate promotes asymmetric growth of the growth plate to thereby correct the angular deformation.

[0011] Another aspect of the present invention provides a method of correcting angular deformation of a bone structure having a first bone portion separated from a second bone portion by a growth plate. The method comprises providing an orthopedic device having a first hinge member pivotally connected to a second hinge member at a pivot joint, aligning the pivot joint with the growth plate, and mounting the first and second hinge members to the first and second bone portions, respectively. In this manner, alignment of the pivot joint with the growth plate promotes asymmetric growth of the growth plate to thereby correct the angular deformation.

Problems solved by technology

Either of these conditions in one or both legs may result in improper load distribution on the knee joint, causing swelling, knee pain, loss of stability, subluxation, increased joint arthritis, and other conditions that restrict one's lifestyle.

The depth of the wedge is critical in that if the wedge is too shallow, thus rendering the bridge too wide, the resulting wide fulcrum results in over stressing of the medial cortex during wedge compression, causing fracture of the bone bridge.

If the wedge is too deep (the residual bone bridge is too narrow) the residual bone bridge, if not completely severed, may lack sufficient strength to provide medial stability to the reduced osteotomy.

However, this technique involves destruction of one half of the growth plate and therefore not a viable option for all patients.

Although hemiepiphyseal stapling is, in some instances, advantageous over other techniques, it suffers from numerous drawbacks.

However, since the staple 10 must have prongs 14, 16 of sufficient length to ensure firm anchorage into the distal femur, more of the physis may be restricted from growth than desired, leading to less bone angle correction.

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