S82.51XP Displaced fracture of medial malleolus of right tibia, subsequent encounter for closed fracture with malunion

ICD-10-CM S82.51XP: Displaced fracture of medial malleolus of right tibia, subsequent encounter for closed fracture with malunion

ICD-10-CM code S82.51XP designates a subsequent encounter for a closed, displaced medial malleolus fracture of the right tibia that has healed with malunion. The medial malleolus is a structure of the distal tibia. Clinical literature notes that medial malleolus fractures can be isolated injuries or part of broader ankle trauma, and malunion can occur postoperatively. 1 2 4

Plain-language overview

The medial malleolus is a structure of the distal tibia, and fractures involving it may occur in isolation or as part of a bi- or tri-malleolar ankle injury. This provides anatomical context for the injury designated by code S82.51XP. 1 2

What this code represents

Code S82.51XP represents a displaced fracture of the medial malleolus of the right tibia for a subsequent encounter for a closed fracture with malunion. This distinguishes it from initial encounters or subsequent encounters for routine healing. 4

Coding details

The code S82.51XP is listed alongside other specific seventh-character extensions for right medial malleolus fractures, such as S82.51XD for routine healing and S82.51XK for nonunion of a closed fracture. This illustrates the coding structure's differentiation of healing phases. 4

The code tree for S82.51XP also distinguishes closed fractures from open fractures, as seen with S82.51XR which designates a subsequent encounter for an open fracture type IIIA, IIIB, or IIIC with malunion. This highlights the specificity required based on fracture severity. 4

Clinical context

Clinical literature establishes that a patient can develop a malunion of a medial malleolus fracture, as observed on a radiograph made at four months postoperatively. This clinical outcome aligns with the malunion designation in code S82.51XP. 1

Documentation considerations

Clinical chart review is used to determine whether a medial malleolus fracture is open or closed. This review process directly supports the documentation needed to select the correct closed fracture designation in code S82.51XP. 1

What the sources add

While the ICD-10-CM source provides the specific code hierarchy and encounter designations for right tibia medial malleolus fractures, the clinical source adds context by documenting a specific case of postoperative malunion. Together, they link the coding terminology to documented clinical outcomes. 1 4

The clinical sources describe the medial malleolus as part of the distal tibia forming the ankle mortise, and note that surgical fixation can involve open or percutaneous approaches. This provides anatomical and procedural background not detailed in the coding source. 1 2

Sources

1. Comparison of Open Reduction and Internal Fixation Versus Closed Reduction and Percutaneous Fixation for Medial Malleolus Fractures — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-25.
3. Malleoli fracture management with minimal resources — surgeryreference.aofoundation.org; accessed 2026-07-25.
4. ICD-10-CM 2024 | S82.51XF - Displaced fracture of medial malleolus of right tibia [subsequent encounter for open fracture type IIIA, IIIB, or IIIC with routine healing] — unboundmedicine.com; accessed 2026-07-25.