ESPE Abstracts (2016) 86 RFC2.4

aCHU de Besançon, Besançon, France; bAPHP, CMR Calcium-Phosphore, Bicêtre Paris Sud, Le Kremlin Bicêtre, France; cAPHP, Necker-Enfants Malades, Paris, France


Background: XLHR is due to mutations in the PHEX gene leading to unregulated production of FGF23, hence hypophosphatemia and decreased renal 1,25OH-vitamin D hydroxylation. Amongst other features, XLHR is characterized by leg bowing of variable severity. Phosphate supplements and oral 1,25OH-vitamin D, partially or, in some cases, fully restore the limb straightness. For severe or residual limb deformities, orthopaedic surgery may be recommended.

Objective: To retrospectively assess the results of surgical limb correction in XLHR children.

Methods: We analysed the relapse incidence and the post-surgical complications in 49 XLHR children (19M, 30F) bearing a PHEX mutation (mean age at diagnosis 5.6 years (±6.5)) who underwent at least one leg surgery.

Results: At first surgery, the mean age was 13.4 years (±5.0), 70% of the patients had a genu varum. Except for 3 transient epiphysiodeses, most surgical corrections were done through osteotomies. 14/49 (29%) of the patients relapsed after the 1st surgery. The age at surgery was inversely correlated with the risk of relapse. The number of additional surgeries significantly decreased with age (2.0 (±0.9), 1.7 (±0.9) et 1.2 (±0.35) in children <11 years, between 11 and 15, and >15 years; P<0.001). Above the age of 11 years, patients having a good metabolic control of the rickets (normal alkaline phosphatases) seem to present with a lower incidence of relapse (28% vs 44% in children<11 years). 20% of the patients had complications (different from the recurrence of the bony deformity) including pseudarthrosis, infection or fractures.

Conclusion: We report here the largest series of surgical procedures in XLHR. Our results confirm that phosphate supplements and vitamin D analogues therapy is the first line of treatment in XLHR to correct the leg bowing. Early surgeries are associated with a high risk of relapse of the limb deformity. Such procedures should be recommended, as a multidisciplinary decision, only in patients with severe distortion leading to mechanical joint and ligaments complications, or for residual deformities once growth plates are fused.

Article tools

My recent searches

No recent searches.