Morphological Variations in Haemophilic Knee Arthropathy: Surgical Implications for Total Knee Arthroplasty Component Selection and Bone Preparation.

AIM: Knee arthropathy affects 90% of patients with severe haemophilia, with unique morphological changes making TKA technically challenging. We evaluated morphological features of haemophilic knees compared to osteoarthritic controls and provide evidence-based surgical recommendations.

METHODS

We evaluated 16 haemophilic patients undergoing TKA with 18 gender-matched non-haemophilic OA patients. This represents the largest intraoperative morphometric study of haemophilic knees to date. Morphological indices including femoral mediolateral width (fML), femoral anteroposterior length (fAP), tibial mediolateral width (tML), tibial anteroposterior length (tAP), and intercondylar notch size were assessed using sterile callipers intraoperatively. Clinical correlation with component sizing, surgical technique modifications (femoral component rotation adjustments, modified notch preparation, soft tissue balancing), and early outcomes were analysed.

RESULTS

The haemophilic group exhibited significantly greater fML (78.21 ± 5.34 vs. 70.41 ± 4.34 mm, p = 0.005) and higher aspect ratio (ML/AP: 1.33 ± 0.05 vs. 1.20 ± 0.04, p = 0.03) compared to OA controls. Haemophilic patients had significantly larger intercondylar notch (19.23 ± 1.2 vs. 14.2 ± 1.56 mm, p = 0.03) and more external rotation based on posterior condylar axis (4.1 ± 0.05 vs. 3.2 ± 0.03 degrees, p = 0.03). These differences resulted in component size selection changes in 75% of cases (12/16) and required surgical technique modifications including altered femoral component rotation in 68.75% of cases (11/16).

CONCLUSION

Haemophilic knees demonstrate distinct morphological characteristics with practical implications for TKA. Modified surgical techniques accommodating wider mediolateral dimensions and altered rotational dynamics can be implemented with existing implants and standard instrumentation. These observations may inform the estimated 1200-1500 haemophilic TKAs performed annually worldwide, though multicentre validation is needed.