Migration behaviour of 2 clinically excellent cementless stems with different design rationales: 5-year follow-up of a randomised RSA-study.

INTRODUCTION: Excellent long-term survival has been reported for both the Taperloc and the Mallory-Head cementless stems. However, little is known about the migration behaviour of these stems which have different design rationales. The purpose of this randomised clinical trial was to compare the migration and clinical outcomes of these stems during 5 years of follow-up. METHODS: 42 consecutive hips in 38 patients scheduled to receive cementless THA were randomised to either a Taperloc or a Mallory-Head stem. Evaluation took place preoperatively and postoperatively on the second day, at 6, 12, 26, and 52 weeks, and annually thereafter. Primary outcome was stem migration measured using roentgen stereophotogrammetric analysis (RSA) and secondary outcomes were the Harris Hip Score (HHS) and 36-Item Short-Form Health Survey (SF-36). No patients were lost to follow-up; in 1 patient the THA was removed due to deep infection 3 months postoperatively. In 6 hips migration measurements were not possible due to insufficient marker configuration. RESULTS: Throughout the follow-up period of 5 years, 3-dimensional migration was comparable between the Taperloc and the Mallory-Head stems (p-values > 0.05). However, at the 5-year follow-up point the retroversion of the Mallory-Head stem was 0.9° more than the Taperloc stem (p = 0.04). Initial subsidence and retroversion were respectively as large as 6.8 mm and 3.6° for the Taperloc stem and 5 mm and 3.6° for the Mallory-Head stem. After the first postoperative year, both implants had stabilised. The mean increment of HHS, as well as the SF-36 scores during the 5-year follow-up, were comparable between the 2 stems. CONCLUSIONS: The excellent long-term survival of both designs was confirmed in this study showing comparable initial migration with subsequent stabilisation. However, the Taperloc design with a flat, wedged geometry showed better rotational stability.

Joint needle aspiration compared to tissue samples in septic arthritis of the native knee.

Culture of the causative infectious agent is the only definitive method of diagnosing septic arthritis and can be identified by culture of synovial fluid (SF) or by tissue cultures (TC) obtained at surgery. The aim of this study is to compare the cultures of joint needle aspiration (JNA) with tissue cultures obtained at surgery. 52 patients treated for a suspicion of a septic arthritis of the native knee were retrospectively reviewed. In 84% tissue cultures were equal to joint needle aspiration. Median Gächter classification was 1.0 (range 1-3). 60% of the patients underwent multiple procedures. All patients were successfully treated with an average of 2.0 (range 1-6) arthroscopies. Our results showed that if a patient with a clinical suspicion of septic arthritis is treated, starting antibiotic therapy prior to surgery can be considered, but only after joint needle aspiration to obtain samples for bacteriologic culture. Arthroscopic surgery must be the treatment of choice in Gächter stage 1 to 3, although it might be necessary to perform multiple procedures.

Surgical Approaches and Hemiarthroplasty Outcomes for Femoral Neck Fractures: A Meta-Analysis.

BACKGROUND: The lateral approach (LA), posterior approach (PA), and anterior approach (AA) are conventional surgical access routes for hemiarthroplasty in proximal femoral fractures. This meta-analysis assesses and compares the outcomes and attempts to identify the best approach for hemiarthroplasty in the treatment of proximal femoral fractures. METHODS: An electronic search was performed from inception to October 25, 2017, for comparative studies including at least 2 of the conventional approaches. Outcomes including operation time, surgical blood loss, perioperative fractures, wound infections, dislocations, and hospital length of stay were plotted in forest plots. RESULTS: Twenty-one eligible studies were selected including 3 randomized, controlled trials, 7 prospective and 11 retrospective cohort studies. The odds ratio (OR) for dislocations was significantly higher for the PA compared with the AA (OR, 2.61; 95% confidence interval [CI], 1.26 to 5.43; P = .01) and the LA (OR, 2.90; 95% CI, 1.63 to 5.14; P = .0003). The PA had a higher risk of reoperation compared to the AA (OR, 1.25; 95% CI, 1.12 to 1.41; P < .0001). No significant differences were found concerning perioperative fractures, wound infections, and hospital length of stay. Some studies suggest a better short-term functional outcome using the AA compared to the PA. CONCLUSION: The PA for hemiarthroplasty in proximal femoral fractures poses an increased risk of dislocation and reoperation compared to the LA and AA. There are no evident advantages of the PA and its routine use for fracture-related hemiarthroplasty should be questioned.

Lack of high BMI-related features in adipocytes and inflammatory cells in the infrapatellar fat pad (IFP).

BACKGROUND: Obesity is associated with the development and progression of osteoarthritis (OA). Although the infrapatellar fat pad (IFP) could be involved in this association, due to its intracapsular localization in the knee joint, there is currently little known about the effect of obesity on the IFP. Therefore, we investigated cellular and molecular body mass index (BMI)-related features in the IFP of OA patients. METHODS: Patients with knee OA (N = 155, 68% women, mean age 65 years, mean (SD) BMI 29.9 kg/m2 (5.7)) were recruited: IFP volume was determined by magnetic resonance imaging in 79 patients with knee OA, while IFPs and subcutaneous adipose tissue (SCAT) were obtained from 106 patients undergoing arthroplasty. Crown-like structures (CLS) were determined using immunohistochemical analysis. Adipocyte size was determined by light microscopy and histological analysis. Stromal vascular fraction (SVF) cells were characterized by flow cytometry. RESULTS: IFP volume (mean (SD) 23.6 (5.4) mm3) was associated with height, but not with BMI or other obesity-related features. Likewise, volume and size of IFP adipocytes (mean 271 pl, mean 1933 µm) was not correlated with BMI. Few CLS were observed in the IFP, with no differences between overweight/obese and lean individuals. Moreover, high BMI was not associated with higher SVF immune cell numbers in the IFP, nor with changes in their phenotype. No BMI-associated molecular differences were observed, besides an increase in TNFα expression with high BMI. Macrophages in the IFP were mostly pro-inflammatory, producing IL-6 and TNFα, but little IL-10. Interestingly, however, CD206 and CD163 were associated with an anti-inflammatory phenotype, were the most abundantly expressed surface markers on macrophages (81% and 41%, respectively) and CD163+ macrophages had a more activated and pro-inflammatory phenotype than their CD163- counterparts. CONCLUSIONS: BMI-related features usually observed in SCAT and visceral adipose tissue could not be detected in the IFP of OA patients, a fat depot implicated in OA pathogenesis.