Gold standard for the management of non-union is open surgical debridement, stabilisation, and autologous bone grafting. LIPUS is becoming more popular, yet the evidence is still inconclusive. LIPUS involves the use of ultrasound at the fracture site with little risk to the patient.

The purpose of this study was to assess effectiveness and cost benefit of LIPUS in the management of non-unions post sustaining an open fracture.

We retrospectively reviewed 29 patients with open fractures with established non-union undergoing LIPUS since 2010 (4 females, mean age 48) range 3–27 months, mean 9 months, either post injury or last intervention. All were tertiary referrals, sustaining injuries to the following areas; Tibial 21, Femur 6, Humerus 2, Radius 1. Definitive fixation being; 9 TSF's, 11 IMN's, 9 plates. (undergoing a mean 2.4 procedures). Aside from sustaining an open fracture, 7 had risk factors for non-unions 5 smokers, 2 NSAID's. Failure of treatment was based on undertaking bone grafting.

In 28 patients (1 lost to follow up) union was achieved in 71% (mean 157 days). All were screened for infection, 4 had organisms on enrichment culture. 8 (5 Gustillo Anderson Grade 3A/B) injuries did not show evidence of callus formation, LIPUS was discontinued and grafting performed. Open fractures were graded as; 7 Grade 1, 4 Grade 2, 8 Grade 3A, 10 Grade 3B being received. Of these; 20 underwent primary closure, 6 free flaps and 3 SSG. The cost of LIPUS is approx £2500, compared bone grafting using autologous iliac crest graft with no medical comorbidities of £3715.

This case series further supports union rates after LIPUS. Cost and morbidity benefit of utilising LIPUS over opting for bone grafting initially is £1215 per patient. Whilst autologous bone grafting is currently the gold standard, it is not without morbidity. We achieved union rates of 71% despite a number of patients having recognised risk factors, showing that LIPUS is a useful resource in the management of non-union.

It is thought that metal ions from metal on metal bearing hip replacements cause DNA damage and immune dysfunction in the form of T cell mediated hypersensitivity. To explore the hypothesis that there is a relationship between metal ion levels and DNA damage and immune dysfunction in matched patient groups of hip resurfacings and standard hip replacements reflected in the levels of lymphocyte subtypes (CD3+ T cells, CD4+ T helper cells, CD8 +T cytotoxic/suppressor cells, CD16 +Natural Killer and CD19+ B cells) in peripheral blood samples, we analysed peripheral blood samples from 68 patients: 34 in the hip resurfacing group and 34 in the standard hip arthroplasty group. Samples were analysed for counts of each sub-group of lymphocyte and cytokine production. Whole blood cobalt and chromium ion levels were measured using inductively-coupled mass spectrometry. All hip components were well fixed.

Cobalt and chromium levels were significantly elevated in the resurfacing group compared to the hybrid group (p<0.001). There was a statistically significant decrease in the resurfacing group's level of CD8+ cells (T cytotoxic/suppressor) (p=0.010). No other subgroup of lymphocytes was significantly affected. Gamma interferon levels post antigen challenge were severely depressed in the hip resurfacing group.

A threshold level of blood cobalt and chromium ions for depression of CD8+ T cells was observed. Hip resurfacing patients have levels above this threshold whilst standard hip replacements fall below it. The patients all had normal levels of CD16 +Natural Killer and CD19+ B cells suggesting that this is not a bone marrow toxic effect. Cytokine analysis confirmed that some aspects of T cell function in hip resurfacing patients are severely depressed.