Ankle Mortise Instability in Multiple Hereditary Exostoses

Area of Science:

• Orthopedics
• Genetics
• Radiology

Background:

• Multiple hereditary exostoses (MHE) is a genetic disorder characterized by the development of multiple bony outgrowths.
• Ankle valgus and mortise widening are common skeletal abnormalities associated with MHE, potentially leading to pain and functional limitations.

Purpose of the Study:

• To characterize mortise widening in MHE patients.
• To evaluate the progression of ankle deformities over time.
• To assess the outcomes of surgical interventions on ankle pain and function at skeletal maturity.

Main Methods:

• Retrospective review of 16 patients (19 ankles) with MHE and mortise widening.
• Radiographic measurements (medial space, talocrural angle, tibiotalar angle) preoperatively and at follow-up.
• Analysis of operative data, complications, and patient-reported outcomes (AOFAS, SF-36 scores).

Main Results:

• 15 ankles (78.9%) presented with clinical valgus; 11 (57.9%) were painful preoperatively.
• Surgical intervention, primarily medial distal tibia hemiepiphysiodesis, resulted in modest improvements in mortise medial space and tibiotalar angle, but angles did not normalize.
• Talocrural angle remained within normal limits, but indicated fibular shortening and potential for talar shift, impacting ankle stability.

Conclusions:

• Surgical correction for MHE-related ankle valgus and mortise widening yields modest radiographic improvements.
• The achieved correction may be insufficient to restore full ankle stability and function.
• Further research is needed to optimize treatment strategies for MHE-associated ankle deformities.