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Predicting translational deformity following opening-wedge osteotomy for lower limb realignment.

Barksfield RC, Monsell FP - Strategies Trauma Limb Reconstr (2015)

Bottom Line: A simulated model was developed using TraumaCad online digital software suite (Brainlab AG, Germany).Osteotomies were simulated in the distal femur, proximal tibia and distal tibia for nine sets of lower limb scanograms at incremental distances from the CORA and the resulting translational deformity recorded.There was excellent agreement between the predictive algorithm and simulated translational deformity for all nine simulations (correlation coefficient 0.93-0.99, p < 0.0001).

View Article: PubMed Central - PubMed

Affiliation: Bristol Royal Hospital for Children, Paul O'Gorman Building, Upper Maudlin Street, Bristol, BS2 8BJ, UK. rcbarksfield@hotmail.com.

ABSTRACT
An opening-wedge osteotomy is well recognised for the management of limb deformity and requires an understanding of the principles of geometry. Translation at the osteotomy is needed when the osteotomy is performed away from the centre of rotation of angulation (CORA), but the amount of translation varies with the distance from the CORA. This translation enables proximal and distal axes on either side of the proposed osteotomy to realign. We have developed two experimental models to establish whether the amount of translation required (based on the translation deformity created) can be predicted based upon simple trigonometry. A predictive algorithm was derived where translational deformity was predicted as 2(tan α × d), where α represents 50 % of the desired angular correction, and d is the distance of the desired osteotomy site from the CORA. A simulated model was developed using TraumaCad online digital software suite (Brainlab AG, Germany). Osteotomies were simulated in the distal femur, proximal tibia and distal tibia for nine sets of lower limb scanograms at incremental distances from the CORA and the resulting translational deformity recorded. There was strong correlation between the distance of the osteotomy from the CORA and simulated translation deformity for distal femoral deformities (correlation coefficient 0.99, p < 0.0001), proximal tibial deformities (correlation coefficient 0.93-0.99, p < 0.0001) and distal tibial deformities (correlation coefficient 0.99, p < 0.0001). There was excellent agreement between the predictive algorithm and simulated translational deformity for all nine simulations (correlation coefficient 0.93-0.99, p < 0.0001). Translational deformity following corrective osteotomy for lower limb deformity can be anticipated and predicted based upon the angular correction and the distance between the planned osteotomy site and the CORA.

No MeSH data available.


Related in: MedlinePlus

Chart demonstrating the predicted translational deformity for opening-wedge osteotomy for a range of angular corrections and distances from the CORA
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Fig7: Chart demonstrating the predicted translational deformity for opening-wedge osteotomy for a range of angular corrections and distances from the CORA

Mentions: Translation following corrective osteotomy for lower limb deformity can be anticipated and predicted based upon the angular correction and the relationship between the planned osteotomy site and the CORA. In most cases, significant translational deformity can be avoided by an appreciation of the site of the CORA and execution of the osteotomy at this level. There are, however, occasions where optimal placement of the osteotomy site is not possible either due to soft tissue considerations and previous instrumentation, or periarticular deformity in which fixation may become tenuous in the resulting bone fragments [5]. Under these circumstances, it is useful to have an appreciation of the obligatory translation that will result, and we have therefore developed a predictive model to estimate this in most cases (Fig. 7; Table 1).Fig. 7


Predicting translational deformity following opening-wedge osteotomy for lower limb realignment.

Barksfield RC, Monsell FP - Strategies Trauma Limb Reconstr (2015)

Chart demonstrating the predicted translational deformity for opening-wedge osteotomy for a range of angular corrections and distances from the CORA
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4666231&req=5

Fig7: Chart demonstrating the predicted translational deformity for opening-wedge osteotomy for a range of angular corrections and distances from the CORA
Mentions: Translation following corrective osteotomy for lower limb deformity can be anticipated and predicted based upon the angular correction and the relationship between the planned osteotomy site and the CORA. In most cases, significant translational deformity can be avoided by an appreciation of the site of the CORA and execution of the osteotomy at this level. There are, however, occasions where optimal placement of the osteotomy site is not possible either due to soft tissue considerations and previous instrumentation, or periarticular deformity in which fixation may become tenuous in the resulting bone fragments [5]. Under these circumstances, it is useful to have an appreciation of the obligatory translation that will result, and we have therefore developed a predictive model to estimate this in most cases (Fig. 7; Table 1).Fig. 7

Bottom Line: A simulated model was developed using TraumaCad online digital software suite (Brainlab AG, Germany).Osteotomies were simulated in the distal femur, proximal tibia and distal tibia for nine sets of lower limb scanograms at incremental distances from the CORA and the resulting translational deformity recorded.There was excellent agreement between the predictive algorithm and simulated translational deformity for all nine simulations (correlation coefficient 0.93-0.99, p < 0.0001).

View Article: PubMed Central - PubMed

Affiliation: Bristol Royal Hospital for Children, Paul O'Gorman Building, Upper Maudlin Street, Bristol, BS2 8BJ, UK. rcbarksfield@hotmail.com.

ABSTRACT
An opening-wedge osteotomy is well recognised for the management of limb deformity and requires an understanding of the principles of geometry. Translation at the osteotomy is needed when the osteotomy is performed away from the centre of rotation of angulation (CORA), but the amount of translation varies with the distance from the CORA. This translation enables proximal and distal axes on either side of the proposed osteotomy to realign. We have developed two experimental models to establish whether the amount of translation required (based on the translation deformity created) can be predicted based upon simple trigonometry. A predictive algorithm was derived where translational deformity was predicted as 2(tan α × d), where α represents 50 % of the desired angular correction, and d is the distance of the desired osteotomy site from the CORA. A simulated model was developed using TraumaCad online digital software suite (Brainlab AG, Germany). Osteotomies were simulated in the distal femur, proximal tibia and distal tibia for nine sets of lower limb scanograms at incremental distances from the CORA and the resulting translational deformity recorded. There was strong correlation between the distance of the osteotomy from the CORA and simulated translation deformity for distal femoral deformities (correlation coefficient 0.99, p < 0.0001), proximal tibial deformities (correlation coefficient 0.93-0.99, p < 0.0001) and distal tibial deformities (correlation coefficient 0.99, p < 0.0001). There was excellent agreement between the predictive algorithm and simulated translational deformity for all nine simulations (correlation coefficient 0.93-0.99, p < 0.0001). Translational deformity following corrective osteotomy for lower limb deformity can be anticipated and predicted based upon the angular correction and the distance between the planned osteotomy site and the CORA.

No MeSH data available.


Related in: MedlinePlus