A comparison of tension-band plate growth modulation in mucopolysaccharidoses versus idiopathic angular deformities

This study compares the outcomes of tension-band plates (TBP) correction of angular deformities in patients with Hurler and Morquoio syndromes mucopolysaccharidoses (MPS) to those with idiopathic etiologies. A retrospective analysis of patients aged less than 18 at a single institution who received TBP between 2005 and 2017 for valgus angular deformities was conducted. Inclusion criteria were patients with complete data and MPS or idiopathic etiology. Femoral and tibial deformities were evaluated independently. Postsurgical X-rays were reported at 6-month intervals. Statistical significance was determined by Mann-Whitney and χ2 tests. Twenty-nine patients were included: Hurler syndrome (8), Morquio syndrome (1), and idiopathic (20). Femoral TBP corrections at 1 year were 4.9° (MPS) and 11.2° (idiopathic); total degrees of correction were 7.3° (MPS) and 8.9° (idiopathic). Tibial TBP corrections at 1 year were 5.8° (MPS) and 5.4° (idiopathic); total degrees of correction were 9.1° (MPS) and 6.0° (idiopathic). The average correction rates for femoral TBPs were 4.3°/year (MPS) and 7.3°/year (idiopathic), and tibial TBPs were 4.5°/year (MPS) and 4.6°/year (idiopathic). Full correction was achieved in four of nine (44.4%) MPS patients and 14 of 20 (70%) idiopathic patients, as well as 9 of 22 (40.9%) MPS limbs and 20 of 38 (52.6%) idiopathic limbs. There were no statistically significant differences between groups or by gender. MPS patients with femoral and tibial TBPs experienced comparable correction rates to idiopathic patients, although idiopathic patients corrected slightly faster, consistent with prior literature. This demonstrates that TBP is an effective growth modulation technique for MPS patients despite morphological differences.