We concluded that the stem failure was initiated by a fretting fatigue mechanism and was propagated by a pure bending fatigue mechanism. Risk factors for fractures of the modular junction include excessive body weight and inadequate proximal osseous support because of trochanteric osteotomy, reduced preoperative bone stock, osteolysis, loosening, and/or implant undersizing. Surgeons should consider the use of implants with strengthened junctions when using modular stems in such patients.

Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment. We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of > 5 mm. In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p < 0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve. Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option.

Moderate and severe pes planus was associated with nearly double the rate of anterior knee pain and intermittent low back pain, while mild pes planus was associated with no higher rate for these problems. Prophylactic measures may be helpful only in those adolescents with moderate and severe pes planus.

No abstract