Blood metal ion levels are not a useful test for adverse reactions to metal debris: A systematic review and meta-analysis.

OBJECTIVES: Alarm over the reported high failure rates for metal-on-metal (MoM) hip implants as well as their potential for locally aggressive Adverse Reactions to Metal Debris (ARMDs) has prompted government agencies, internationally, to recommend the monitoring of patients with MoM hip implants. Some have advised that a blood ion level >7 µg/L indicates potential for ARMDs. We report a systematic review and meta-analysis of the performance of metal ion testing for ARMDs. METHODS: We searched MEDLINE and EMBASE to identify articles from which it was possible to reconstruct a 2 × 2 table. Two readers independently reviewed all articles and extracted data using explicit criteria. We computed a summary receiver operating curve using a Bayesian random-effects hierarchical model. RESULTS: Our literature search returned 575 unique articles; only six met inclusion criteria defined a priori. The discriminative capacity of ion tests was homogeneous across studies but that there was substantial cut-point heterogeneity. Our best estimate of the "true" area under curve (AUC) for metal ion testing is 0.615, with a 95% credible interval of 0.480 to 0.735, thus we can state that the probability that metal ion testing is actually clinically useful with an AUC ≥ 0.75 is 1.7%. CONCLUSION: Metal ion levels are not useful as a screening test for identifying high risk patients because ion testing will either lead to a large burden of false positive patients, or otherwise marginally modify the pre-test probability. With the availability of more accurate non-invasive tests, we did not find any evidence for using blood ion levels to diagnose symptomatic patients.Cite this article: M. Pahuta, J. M. Smolders, J. L. van Susante, J. Peck, P. R. Kim, P. E. Beaule. Blood metal ion levels are not a useful test for adverse reactions to metal debris: a systematic review and meta-analysis. Bone Joint Res 2016;5:379-386. DOI: 10.1302/2046-3758.59.BJR-2016-0027.R1.

A randomised clinical trial comparing minimally invasive surgery to conventional approach for endoprosthesis in elderly patients with hip fractures.

BACKGROUND: In recent years, the concept of minimally invasive surgery has invaded the orthopaedic field and literature on the subject is spawning. Mini-incision surgery for total hip arthroplasty has been studied without a clear consensus on the efficacy, safety and advantage of that technique. To our knowledge, the efficacy and safety of mini-incisions in hip fracture surgery has not been studied in a randomised fashion. METHODS: This study is a prospective clinically randomised trial whose primary objective was to demonstrate the safety and efficacy of a single posterior mini-incision approach compared to a standard posterior approach for endoprosthesis in acute femoral neck fractures. The mini-incision was defined as less than 8 cm. 25 patients in the mini-incision surgery (MIS) group and 31 patients in the standard incision group (STD) were available for analysis. The following validated disease-specific outcome instruments were used: the Lower Extremity Measurement (LEM) and the Time Up and Go (TUG). Secondary endpoints of pain, function, and quality of life were assessed by the components of the Harris Hip Score (HHS) and SF-36. Radiographic outcomes were also evaluated as well as the rates of all reported complications and adverse events during the 2 years follow-up. RESULTS: There was no significant difference for operative time, blood losses, 72 h postoperative haemoglobin as well as the need for transfusion therapy between the two groups. Also, there was no difference between the groups for postoperative morphine use and pain evaluation with the Visual Analog Scale. The functional assessment using LEM and TUG did not demonstrate any statistically significant difference between mini- and standard incision. However, the HHS and the physical function component of the SF-36 were statistically better at 2 years in favour of the standard incision group. CONCLUSION: Based on the results of the present study, we cannot recommend the use of a minimally invasive approach over a standard approach in the implantation of a cemented endoprosthesis.

Histologic analysis of fetal ulnar variance.

Twenty-eight fetal wrists aged 5 to 21 weeks gestation were examined histologically to assess ulnar variance. There was a trend from ulna negative to ulna neutral among this population. Of 10 wrists in group I (5-8 weeks gestation), 8 were ulna negative and 2 were ulna neutral. Of nine wrists in group II (11-13 weeks gestation), three were ulna negative and six were ulna neutral. Of nine wrists in group III (18-21 weeks gestation), two were ulna negative and seven were ulna neutral. Overall, 13 embryos demonstrated an ulna negative variance; the remainder had ulna neutral variance. These results are significantly different than the incidence of ulnar variance in adults. With growth, factors must occur that change this fetal relationship of radius to ulna.