Introduction. Metal on metal articulations produce chromium (Cr) and cobalt (Co) debris, particularly when the articulations are worn in. High levels in the peripheral blood are indicative of excess wear and may cause adverse effects. The present RCT investigates metal ion levels and the relationship of Co, Cr ions and lymphocyte counts during the running-in period. Materials and Methods. Following randomization to RHA (ASRTM, DePuy) or THA we obtained whole blood (wb), and serum (s) samples at baseline, 8 w, 6 m and 1 y. We measured the Co and Cr concentrations, the total lymphocyte count as well as the CD3+, CD4+, CD8+, CD19+ and CD16+/CD56+ sub populations. Cup inclination and anteversion angles came from conventional radiographs. Activity was measured as steps by pedometer and UCLA activity. Data are presented as median (range). Results. We had 19 patients in each group. Age 57 (46–64) y (RHA) and 55 (44–64) y (THA). RHA only: head size: 51 (47 to 57)mm, cup inclination: 45.0 (40- 56)° and anteversion: 23 (7–38)°. The ion concentrations stayed below 0.2 ppb for THAs. For RHAs the Co and Cr concentrations generally rose markedly in the initial 8 weeks, followed by a slower ascent up to 1 year to wb Co: 1.0 (0.6–5.2), s Co: 1.3 (0.7–6.5), wb Cr: 1.3 (0.4–8.0) and s Cr: 1.7 (0.6–15) ppb. A high ion level was correlated to a small head size (p<0.03) and a cup inclination around 45° (p<0.04). We could not correlate the ion concentrations to the anteversion or the activity levels. The absolute lymphocyte counts were not always identical in the groups (eg. lower CD8+ for RHA) but there was no group difference when we analysed the change from baseline. We did not demonstrate any correlation between metal ion levels and lymphocyte subpopulations. Discussion. The findings of this study does not support the theory that metal ions suppress the lymphocytes or the CD8+ in particular (Hart et al., 2009). Our conclusions are limited by low numbers, but we suspect the theory could be biased by missing baseline values. Our study did not demonstrate the same 6–9 months ion peak found in other running-in studies (Back et al., 2005, Heisel et al., 2008), but rather a slow continuous rise with lower median ion concentrations. It could indicate lower wear or perhaps a longer running in period in our slightly older population. Contrary to our expectations we found that cups placed in optimal inclination displayed a higher ion level. Most of the smallest cups were found in this group, and the majority of the steep cups had very large heads. For this implant head size may be more important than cup position

Aims. The aim of this study was to evaluate the diagnostic value of preoperative serum CRP, white blood cell count (WBC), percentage of neutrophils (%N), and neutrophil to lymphocyte ratio (NLR) when using the fracture-related infection (FRI) consensus definition. Methods. A cohort of 106 patients having surgery for suspected septic nonunion after failed fracture fixation were studied. Blood samples were collected preoperatively, and the concentration of serum CRP, WBC, and differential cell count were analyzed. The areas under the curve (AUCs) of diagnostic tests were compared using the z-test. Regression trees were constructed and internally cross-validated to derive a simple diagnostic decision tree. Results. Using the FRI consensus definition, 46 patients (43%) were identified as infected. Sensitivity, specificity, and AUC of CRP were 67% (95% confidence interval (CI) 52% to 80%), 61% (95% CI 47% to 74%), and 0.64 (95% CI 0.54 to 0.74); of WBC count were 17% (95% CI 9% to 31%), 95% (95% CI 86% to 99%), and 0.57 (95% CI 0.50 to 0.62); of %N 13% (95% CI 6% to 26%), 87% (95% CI 76% to 93%), and 0.50 (95% CI 0.43 to 0.56); and of NLR 28% (95% CI 17% to 43%), 80% (95% CI 68% to 88%), and 0.54 (95% CI 0.46 to 0.63), respectively. A better performance of serum CRP was shown in comparison to the leucocyte count (p = 0.006), %N (p < 0.001), and NLR (p = 0.001). A statistically lower serum CRP level was shown in patients with an infection caused by a low virulence microorganism in comparison to high virulence bacteria (p = 0.008). We found that a simple decision tree approach using only low serum neutrophils (< 3.615 × 10. 9. /l) and low CRP (< 2.45 mg/l) may allow better identification of aseptic cases. Conclusion. The evaluated serum inflammatory markers showed limited diagnostic value in the preoperative diagnosis of FRI when using the uniform FRI Consensus Definition. Therefore, they should remain as suggestive criteria in diagnosing FRI. Although CRP showed a higher performance in comparison to the other serum markers, it is insufficiently accurate to diagnose a septic nonunion, especially when caused by low virulence microorganisms. Cite this article: Bone Joint J 2020;102-B(7):904–911

Introduction. Neck of femur (NOF) fractures are one of the predominant reasons for hospital admissions in patients >65 year. These fractures are associated with a poor outcome; end to independent living in 60% of patients and a 6 month mortality of 30%. Previous studies have shown show elements of under/mal-nutrition on admission. In addition, their nutritional status shows some deterioration thereafter. The aim of this present study is to examine if the nutritional status of patients with NOF fracture admitted at our institution is associated with a larger post-operative haemoglobin drop. This is compared to an independent living age matched control group from the same geographical area. Methods. A retrospective audit of pathology results for three hundred fracture patients (n = 300) and one hundred age matched home living group pre-assessed of total hip replacement (n = 100). Total serum protein, albumin, total lymphocyte count levels were determined at the time of admission to assess nutritional status. Pre/post-operative haemoglobin, resultant haemoglobin drop, and 6 month mortality was assessed in NOF fracture patients. The nutritional parameters were correlated with the haemoglobin levels and mortality. Results. Fracture patients were found to be malnourished on hospital admission. 10% showed a total serum protein level of <60g/L, 21% showed an albumin level of <35 g/L and 66% had on a total lymphocyte count of <1,200 cells/ml. When compared to an age matched home living group, fracture patients had a significantly (p = <0.0001) lower protein (67.4 vs 74.5), albumin (38.8 vs 43.9) and total lymphocyte counts (1173.3 vs 1840.8). Pre/post-operative haemoglobin showed a positive correlation with albumin and protein levels (p = <0.01). Haemoglobin drop post-operatively showed a negative correlation with albumin and protein levels (p = <0.01). 6 month mortality was correlated with albumin, protein, and total lymphocyte count levels. Discussion. This study confirms that patients admitted with NOF fractures are malnourished on admission. In addition, we report that not only pre-operative haemoglobin is correlated to the malnourishment but also the post-operative haemoglobin drop is correlated to albumin/protein levels on admission. This leads us to hypothesise that these malnourished patients have a higher bleeding tendency. Thus, we propose that malnourishment can be identified by the orthopaedic team using relatively inexpensive laboratory tests such as albumin, protein and total lymphocyte count. Thereafter, appropriate measures should be instituted to prepare for intra/post-operative bleeding and higher need for blood transfusion

In a randomized study of 60 patients allergic reactions are evaluated in three joint prosthesis groups, a resurfacing arthroplasty (ReCap), a non-cemented, large metal-on-metal head (Bimetric Magnum) and a non-cemented, alumina ceramic-on-ceramic bearing in a titanium shell (Bimetric C2a). The inclusion criteria were osteoarthritis, ASA I–II, MRI-scan without caput necrosis, DXA-scan without osteoporosis. The exclusion criteria were short neck (<2cm.), large cysts (>1cm.), medical treatment affecting the bone metabolism, severe deformity of the femoral head, impaired kidney function and inability to co-operate. Blood samples were drawn prior to and 6 weeks, 6 months, 1 year, and 3 years after surgery; two tubes from which plasma was prepared, and two tubes for serum. From the last included 20 patients in each group was also taken blood one and three years after surgery for an in vitro lymphocyte assay for scoring of possible hypersensitivity to prosthesis metals. The isolated lymphocytes were subjected to measurement of proliferation and expression of CD69 by flow cytometry and measurement of the Migration Inhibitory Factor (MIF) by ELISA. Plasma concentrations of the cytokines IL-1, IL-4, IL-6, IL-8, IL-12p70, IL-15, interferon-and osteoprotegerin were determined by multiplex-immunoassay. Serum concentrations of chromium and cobalt were determined by graphite furnace atomic absorption spectrometry. The serum concentrations of chromium and cobalt were lowest in patients with the C2a implant and highest with Magnum, some of these differences were significant at 6 weeks, 6 months, and 1 year after surgery. No patient had a very high serum metal concentration. The values of the variables measured in the in vitro lymphocyte assay mainly changed in the expected direction depending on the concentration of the same metal in the serum sample drawn at the same time, but no significant correlation was seen. One patient had uncertain symptoms of metal hypersensitivity and relatively high serum metal concentrations 3 years after arthroplasty with a Magnum prosthesis and was assessed extraordinarily, and elicited the marginally highest MIF responses in the lymphocyte assay. A strong correlation was found between the plasma concentrations of most cytokines, but the cytokine concentrations were not correlated to contemporary metal concentrations

Aims

Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture.

Background. Pseudotumours have been associated with metal-on-metal (MoM) hip replacements. We define it as a solid mass which may have cystic components that is neither neoplastic nor infectious in aetiology. The cause of a pseudotumour is not fully understood but could be due to excessive wear, metal hypersensitivity or due to an as-yet unknown cause. Aim. We present the retrieval analysis of early failure MoM hips revised for pain, loosening or a symptomatic mass. Tissues and implants were examined for the possible causes of failure and pseudotumour formation. Corrosion as a potential new cause for pseudotumour formation will be presented. Methods. A group of 16 MoM hip replacements were collected for retrieval analysis. Six of which had a pseudotumour. An Artificial Hip Profiler (Redlux Ltd) was used to measure wear. Edge loading was determined using the 3D wear data. Tissues were histologically evaluated using a 10-point ALVAL scoring system, which strongly suggests hypersensitivity (1). Cases were assigned to one of three categories: high wear (rates >5m/yr), hypersensitivity or corrosion. Results. Of the 6 pseudotumours, 3 had edge loading, 2 had high ALVAL scores and one had corrosion at the head taper junction. The high wear group, (3 cases) all demonstrated edge loading. Histology revealed more metal wear particles and macrophages, with a low ALVAL score in these cases. Two cases were found to have hypersensitivity with a high ALVAL score, more lymphocytes with less visible wear debris and macrophages. The wear rates were also lower, <4m/yr. One total hip replacement had corrosion at the junction between the head and adaptor taper for the stem. The bearings had low wear and the tissue had extensive necrosis as well as products of corrosion enclosed in fibrin (2). There was no suggestion of hypersensitivity (low ALVAL score). Conclusion. Pseudotumours can be caused by high wear, but if this is ruled out, a hypersensitivity or corrosion product reaction should be considered

Aims

The primary aim was to assess the independent influence of coronavirus disease (COVID-19) on 30-day mortality for patients with a hip fracture. The secondary aims were to determine whether: 1) there were clinical predictors of COVID-19 status; and 2) whether social lockdown influenced the incidence and epidemiology of hip fractures.

Aims

Low haemoglobin (Hb) at admission has been identified as a risk factor for mortality for elderly patients with hip fractures in some studies. However, this remains controversial. This study aims to analyze the association between Hb level at admission and mortality in elderly patients with hip fracture undergoing surgery.

Aims

Compartment syndrome results from increased intra-compartmental pressure (ICP) causing local tissue ischaemia and cell death, but the systemic effects are not well described. We hypothesised that compartment syndrome would have a profound effect not only on the affected limb, but also on remote organs.

We compared early post-operative rates of wound infection in HIV-positive and -negative patients presenting with open tibial fractures managed with surgical fixation.

The wounds of 84 patients (85 fractures), 28 of whom were HIV positive and 56 were HIV negative, were assessed for signs of infection using the ASEPIS wound score. There were 19 women and 65 men with a mean age of 34.8 years. A total of 57 fractures (17 HIV-positive, 40 HIV-negative) treated with external fixation were also assessed using the Checkett score for pin-site infection. The remaining 28 fractures were treated with internal fixation. No significant difference in early post-operative wound infection between the two groups of patients was found (10.7% (n = 3) vs 19.6% (n = 11); relative risk (RR) 0.55 (95% confidence interval (CI) 0.17 to 1.8); p = 0.32). There was also no significant difference in pin-site infection rates (17.6% (n = 3) vs 12.5% (n = 5); RR 1.62 (95% CI 0.44 to 6.07); p = 0.47).

The study does not support the hypothesis that HIV significantly increases the rate of early wound or pin-site infection in open tibial fractures. We would therefore suggest that a patient’s HIV status should not alter the management of open tibial fractures in patients who have a CD4 count > 350 cells/μl.

Cite this article: Bone Joint J 2013;95-B:1703–7.

There are 33 million people worldwide currently infected with human immunodeficiency virus (HIV). This complex disease affects many of the processes involved in wound and fracture healing, and there is little evidence available to guide the management of open fractures in these patients. Fears of acute and delayed infection often inhibit the use of fixation, which may be the most effective way of achieving union.

This study compared fixation of open fractures in HIV-positive and -negative patients in South Africa, a country with very high rates of both HIV and high-energy trauma. A total of 133 patients (33 HIV-positive) with 135 open fractures fulfilled the inclusion criteria. This cohort is three times larger than in any similar previously published study.

The results suggest that HIV is not a contraindication to internal or external fixation of open fractures in this population, as HIV is not a significant risk factor for acute wound/implant infection. However, subgroup analysis of grade I open fractures in patients with advanced HIV and a low CD4 count (< 350) showed an increased risk of infection; we suggest that grade I open fractures in patients with advanced HIV should be treated by early debridement followed by fixation at an appropriate time.