BackgroundIn young patients with osteonecrosis of the femoral head (ONFH), short-stem total hip arthroplasty (THA) could allow a potential advantage in preserving metaphyseal bone-stock, when revision surgery might become necessary. However, only a few studies have evaluated the outcome of short-stem THAs in ONFH. We reviewed the prospectively collected data of a cementless partial neck-retaining short-stem with ceramic-on-ceramic bearings in ONFH patients.MethodsThirty patients (37 hips) younger than 60 years (mean age at surgery, 51.5 years) underwent THA with the NANOS® stem (Smith and Nephew, Marl, Germany) from January 2006 to December 2012. All patients received a 32-mm or 36 mm ceramic femoral head. Harris hip score, WOMAC and UCLA activity score were recorded. Postoperative radiographs were evaluated for bone-implant fixation and osteolysis. Further analysis correlated clinical findings with implants characteristics and patient demographics at mean 5.6 years’ follow-up (range, 3–10 years).ResultsThe clinical and functional results improved significantly (p < 0.001). At latest follow-up, mean HHS, WOMAC, and UCLA activity scores were 90 (range, 71–100), 94 (range, 76–100), and 6.3 (range, 4–10) points, respectively. The diameter of the femoral head did not influence the clinical outcome (p = 0.661). All hips showed bone ingrowth fixation of the acetabular and femoral components. No patients showed osteolysis. No revision for any reason was performed during the study period.ConclusionsThe excellent clinical results and fixation pattern at mean 5.6 years’ follow-up reveal this implant as a reliable option in advanced stage of ONFH either. Further investigations are crucial to determine the long-term durability and to assess whether the association of ceramic-on-ceramic bearings, can be useful to achieve longer survivorship and lower complications rates.Trial registrationRegistry number: ISRCTN 91336248; date of registration: 04/07/2017.

The role of proximal tibiofibular joint (TFJ) transfixion during Ilizarov tibial lengthening is still debated in the literature. The aim of this study was to show that TFJ transfixion can be avoided with no impact on patient outcome. All achondroplastic patients undergoing tibia lengthening from 1999 to 2018 were included. Patients were divided in two groups: group A (11 patients) submitted to proximal TFJ transfixion and group B (22 patients) not submitted to TFJ transfixion. The results showed a statistically significant difference in proximal fibular migration (PFM) between the two groups of patients, with a mean PFM of 9.2 mm (range, 1-20 mm) and of 21 mm (range, 2.7-76 mm) in group A and in group B, respectively. We can state that PFM up to 41 mm in our series did not affect joint function and stability. There are no statistically significant differences in the other radiological parameters. Analysis of functional scores (Knee Society, Tegner-Lhysolm, Association for the Study and Application of Methods of Ilizarov) did not reveal significant differences between the groups. The scores of the Achondroplasia Personal Life Experience Scale were also similar in the two groups, demonstrating a good quality of life. There are no differences between the two groups in terms of clinical-functional outcome of the knee, radiographic results, and quality of life. Transfixion of proximal TFJ may not be necessary, but it is important to avoid premature consolidation of the fibular osteotomy.

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