Artikel
Surgical reconstruction of complex lower limb deformities by multilevel correction osteotomies and intramedullary nailing in adolescents and adults with hereditary hypophosphatemic rickets
Suche in Medline nach
Autoren
Veröffentlicht: | 22. Oktober 2019 |
---|---|
Veröffentlicht mit Erratum: | 8. November 2019 |
Gliederung
Text
Objectives: Vitamin D-resistant hypophosphatemia (VDRH) is a rare disease characterized by deficient renal tubular reabsorption of phosphate, leading to impaired bone mineralization and rickets. When supplementation therapy fails, patients frequently develop progressive 3-dimensional deformities of the lower extremities (mostly varus, antecurvation and antetorsion). Guided growth can only affect the coronal plane and often results in residual or even secondary deformities. As various techniques of surgical limb reconsturction in patients with VDRH are controversial, our study analyzed multilevel correction osteotomies and intramedullary nailing (IN) in adolescent patients with VDRH.
Methods: 37 lower limb reconstructions with a total of 141 osteotomies in 22 patients with VDRH using IN (Trigen, Smith & Nephew) were performed. Femoral nails were introduced in retrograde, tibial nails in antegrade technique. An average of 3.8±1.2 (2-5) osteotomies per leg was necessary to achieve a correct 3-dimensional alignment. Median age at operation was 19 years (13-59). Pre- and postoperative deformity analysis was done on calibrated long standing a.p. radiographs and lateral radiographs of the thigh and lower leg. Femoral and tibial torsion was assessed clinically or by CT/MRI scan. Statistical analysis was done using MS Excel 2010 and GraphPad Prism 7.0.
Results and conclusion: Mean followup was 21.9±21 months (3-74). All osteotomies healed. In total, the correction extent in coronal plane measured femoral 29.1±14.5°, tibial 18.6±6.8°, in sagittal plane femoral 27.0±12.5° and tibial 15.8±8.8°. Mean mechanical axis deviation (MAD) was significantly corrected from 55.0±30.4 mm before surgery to 12.8±8.3 mm at follow up (p< 0.0001, MAD improvement of 76.7%). Postoperative posterior tibial slope (PTS) was significantly improved from 14.6±7.6° to 9.8±4.2° (p< 0.01). Torsion was sufficiently corrected in all cases. In 1/66 (1,5%) the IN had to be removed due to infection. As IN were kept in situ as permanent implants, no recurrence of deformity has been observed at followup examination. There are various treatment modalities for complex deformities in VDRH, as epiphysiodesis, plate osteosynthesis or external fixator. However, using IN we observed a stable correction without recurrence in the period considered. Although the operative technique might be more challenging, the advantages - such as the low rate of complications as well as the exact and significant correction - are obvious. IN should be kept in situ as permanent implants to prevent fractures and recurrence.
Figure 1 [Fig. 1]