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Direction of the oblique medial malleolar osteotomy for exposure of the talus.

van Bergen CJ, Tuijthof GJ, Sierevelt IN, van Dijk CN - Arch Orthop Trauma Surg (2010)

Bottom Line: Using anteroposterior mortise radiographs and coronal computed tomography (CT) scans of 46 ankles (45 patients) with an osteochondral lesion of the talus, two observers independently measured the intersection angle between the tibial plafond and medial malleolus.The intraobserver (ICC, 0.90-0.93) and interobserver (ICC, 0.65-0.91) reliability of these measurements were good to excellent.A medial malleolar osteotomy directed at a mean 30° relative to the tibial axis enters the joint perpendicularly to the tibial cartilage, and will likely result in a congruent joint surface after reduction.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Orthopaedic Research Center Amsterdam, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. c.j.vanbergen@amc.nl

ABSTRACT

Introduction: A medial malleolar osteotomy is often indicated for operative exposure of posteromedial osteochondral defects and fractures of the talus. To obtain a congruent joint surface after refixation, the oblique osteotomy should be directed perpendicularly to the articular surface of the tibia at the intersection between the tibial plafond and medial malleolus. The purpose of this study was to determine this perpendicular direction in relation to the longitudinal tibial axis for use during surgery.

Materials and methods: Using anteroposterior mortise radiographs and coronal computed tomography (CT) scans of 46 ankles (45 patients) with an osteochondral lesion of the talus, two observers independently measured the intersection angle between the tibial plafond and medial malleolus. The bisector of this angle indicated the osteotomy perpendicular to the tibial articular surface. This osteotomy was measured relative to the longitudinal tibial axis on radiographs. Intraclass correlation coefficients (ICC) were calculated to assess reliability.

Results: The mean osteotomy was 57.2 ± 3.2° relative to the tibial plafond on radiographs and 56.5 ± 2.8 on CT scans. This osteotomy corresponded to 30.4 ± 3.7° relative to the longitudinal tibial axis. The intraobserver (ICC, 0.90-0.93) and interobserver (ICC, 0.65-0.91) reliability of these measurements were good to excellent.

Conclusion: A medial malleolar osteotomy directed at a mean 30° relative to the tibial axis enters the joint perpendicularly to the tibial cartilage, and will likely result in a congruent joint surface after reduction.

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Related in: MedlinePlus

Coronal computed tomography scans of the same patient as in Fig. 5 showing the most anterior (a), middle (b), and most posterior (c) intersection (αα)
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Fig6: Coronal computed tomography scans of the same patient as in Fig. 5 showing the most anterior (a), middle (b), and most posterior (c) intersection (αα)

Mentions: To determine the intra-articular course of the intersection, both observers measured the intersection angle (αα) on the most anterior and the most posterior coronal reconstructions of the tibial plafond, as well as on the middle portion of the tibial plafond, using PACS (Fig. 6). As with the radiographs, the intersection was defined by tangential lines of the tibial plafond and medial malleolar articular facet. The mean of the anterior, middle, and posterior intersection angles was calculated to compare with the radiographic measurements. The bisector of this angle indicated the osteotomy relative to the tibial plafond.Fig. 6


Direction of the oblique medial malleolar osteotomy for exposure of the talus.

van Bergen CJ, Tuijthof GJ, Sierevelt IN, van Dijk CN - Arch Orthop Trauma Surg (2010)

Coronal computed tomography scans of the same patient as in Fig. 5 showing the most anterior (a), middle (b), and most posterior (c) intersection (αα)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3117279&req=5

Fig6: Coronal computed tomography scans of the same patient as in Fig. 5 showing the most anterior (a), middle (b), and most posterior (c) intersection (αα)
Mentions: To determine the intra-articular course of the intersection, both observers measured the intersection angle (αα) on the most anterior and the most posterior coronal reconstructions of the tibial plafond, as well as on the middle portion of the tibial plafond, using PACS (Fig. 6). As with the radiographs, the intersection was defined by tangential lines of the tibial plafond and medial malleolar articular facet. The mean of the anterior, middle, and posterior intersection angles was calculated to compare with the radiographic measurements. The bisector of this angle indicated the osteotomy relative to the tibial plafond.Fig. 6

Bottom Line: Using anteroposterior mortise radiographs and coronal computed tomography (CT) scans of 46 ankles (45 patients) with an osteochondral lesion of the talus, two observers independently measured the intersection angle between the tibial plafond and medial malleolus.The intraobserver (ICC, 0.90-0.93) and interobserver (ICC, 0.65-0.91) reliability of these measurements were good to excellent.A medial malleolar osteotomy directed at a mean 30° relative to the tibial axis enters the joint perpendicularly to the tibial cartilage, and will likely result in a congruent joint surface after reduction.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Orthopaedic Research Center Amsterdam, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. c.j.vanbergen@amc.nl

ABSTRACT

Introduction: A medial malleolar osteotomy is often indicated for operative exposure of posteromedial osteochondral defects and fractures of the talus. To obtain a congruent joint surface after refixation, the oblique osteotomy should be directed perpendicularly to the articular surface of the tibia at the intersection between the tibial plafond and medial malleolus. The purpose of this study was to determine this perpendicular direction in relation to the longitudinal tibial axis for use during surgery.

Materials and methods: Using anteroposterior mortise radiographs and coronal computed tomography (CT) scans of 46 ankles (45 patients) with an osteochondral lesion of the talus, two observers independently measured the intersection angle between the tibial plafond and medial malleolus. The bisector of this angle indicated the osteotomy perpendicular to the tibial articular surface. This osteotomy was measured relative to the longitudinal tibial axis on radiographs. Intraclass correlation coefficients (ICC) were calculated to assess reliability.

Results: The mean osteotomy was 57.2 ± 3.2° relative to the tibial plafond on radiographs and 56.5 ± 2.8 on CT scans. This osteotomy corresponded to 30.4 ± 3.7° relative to the longitudinal tibial axis. The intraobserver (ICC, 0.90-0.93) and interobserver (ICC, 0.65-0.91) reliability of these measurements were good to excellent.

Conclusion: A medial malleolar osteotomy directed at a mean 30° relative to the tibial axis enters the joint perpendicularly to the tibial cartilage, and will likely result in a congruent joint surface after reduction.

Show MeSH
Related in: MedlinePlus