"One millimetre equals one degree": a simple way to achieve in 92% of cases the desired correction after opening proximal tibial osteotomy for genu varum.

INTRODUCTION: When performing a high tibial osteotomy (HTO) for genu varum deformity, it is not always easy to obtain the correct amount of overcorrection. The aims of this study were to review the results of a simple and reproducible method of correction that we have called "1 mm equals 1°". We have applied this technique to the medial opening wedge osteotomy. Our hypothesis was that one degree of correction corresponded with one degree of opening. METHODS: 97 proximal medial opening wedge osteotomies were measured intraoperatively with a navigation system and at 3 months with long-leg X-rays. The hip-knee-ankle (HKA) angle preoperatively was on average 173.8 ± 2.3° (170°-177°). In most cases, an opening of 4° greater than the initial varus was performed using our formula that one degree varus was equal to 1 mm of opening. In other words, when the varus was 6°, an opening of 10 mm was performed. The void left by the opening wedge was filled with a calcium triphosphate wedge and the construct fixed and held with a locking plate. RESULTS: Aiming for a knee axis of 184 ± 2°, which corresponds to 2°-6° of overcorrection, we obtained the following results: HKA intraoperatively measured angle with navigation was on average 183.5 ± 0.9° (182°-184°) and HKA radiologically postoperatively angle was 182.5° ± 1.6° (179°-189°). We therefore achieved the desired overcorrection of 2°-6° in 92% of cases based on our postoperative radiographs and in 100% cases based on intraoperative measurements with computer navigation. CONCLUSION: The method of "1 mm equals 1°" is a simple, reliable, and reproducible method to achieve in 92% of cases the desired overcorrection (i.e., 184 ± 2°) with valgising proximal medial opening wedge osteotomy in genu varum.

Highly Durable Antibacterial Properties of Cellulosic Fabric via ß-Cyclodextrin/Essential Oils Inclusion Complex.

Essential oils (EOS), which naturally come from plants, have significant antibacterial properties against a variety of pathogens, but their high volatility and poor water solubility severely restrict their use in the textile industry. In this study, an inclusion complex based on ß-cyclodextrin (ß-CD)/EOS was prepared by two different simple methods: pad dry cure (method 1) and pad batch (method 2). A glyoxal crosslinking agent was used for the fixation of the inclusion complexes on the surface of the fabric. Lavender, rosemary, salvia, and lemon essential oils were applied. The structure of the ß-CD/EOs inclusion complex was investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and weight gain (%), which indicated that the ß-CD/EOs were successfully deposited on cellulose-based fabric. The results demonstrated that ß-CD enhanced the oils' scent stability, with the advantage of exhibiting no major change in the tensile strength or permeability of cotton. Lavender oil had the highest stability scent with a value of 3.25, even after 30 days of evaluation. The antibacterial activity showed that EOS/ßCD-impregnated fabrics for method 1 had an inhibition zone ranging from 33 to 23 mm, while the inhibition zone for method 2 ranged from 39 mm to 29 mm, indicating that our treatment was able to control the growth of bacteria, even after five washing cycles. This study confirmed that the EOs/ßCD inclusion-complex-deposited cotton fabric might hold further promise for medical and hospital use.

Acute instability of the patella: is magnetic resonance imaging mandatory?

PURPOSE: Acute dislocations of the patella represent 2 to 3% of traumatic injuries of the knee. When patients are seen in the emergency department with a dislocated patella clinical diagnosis is often very evident. However, in cases of short-lived subluxation or dislocations that have reduced spontaneously, the diagnosis can be challenging. The aim of this study was to evaluate the utility of MRI in the evaluation of acute patellar instability. METHODS: This was a prospective study of 39 cases of acute patellar instability. The study protocol included a clinical examination by an emergency medicine doctor, a standardised series of radiographs and an MRI scan within 15 days after injury. RESULTS: The series included 15 female and 24 male patients aged on average 23 ± 10.5 years (11-46). Twenty-four cases were following sporting accidents and 15 cases following domestic accidents. In ten cases, a blow to the medial side of the patella led to the injury and in 29 cases, a twisting mechanism with a valgus and external rotation force was responsible. Six patients presented with a clinically dislocated patella and 31 patients were deemed to have a "swollen knee". Nineteen patients described an episode of subluxation of the patella and 14 an odd sensation within the knee without being able to specifically describe what had happened. Radiographs demonstrated trochlear dysplasia in 97.5% of cases and osteochondral lesions in 20.5% of cases. MRI scan confirmed the diagnosis of acute patellar instability in 37 cases giving a sensitivity of 95%. MRI findings included 25 MPFL lesions, 31 patella lesions of which 25 were bone oedema and six medial facet fractures, 31 lateral femoral condyle bone oedema type lesions, 11 chondral lesions of which seven were osteochondral in nature and also three acute associated ACL injuries and two MCL injuries. CONCLUSION: MRI scan is an important tool in the diagnosis and management of acute patellar dislocation and subluxation. When symptoms are subtle, MRI facilitates a diagnosis with relative ease. MRI is particularly useful in identifying the exact nature of lesions most notably chondral lesions which are frequently of significant size and therefore often require expedited surgical treatment.

Non-Invasive Assessment of Graft Fibrosis After Living Donor Liver Transplantation: Is There Still a Role for Liver Biopsy?

Non-invasive methods have evolved as a surrogate for liver biopsy such as indirect markers (aspartate transaminase to platelet ratio index, fibro-α score), transient elastography (TE), and magnetic resonance elastography (MRE). The aim of this study is to prospectively compare the value of MRE, TE, and indirect markers in detecting and staging allograft fibrosis compared to liver biopsies in patients who have undergone living donor liver transplantation for complications related to hepatitis C virus. A total of 31 living donor liver transplantation recipients with hepatitis C virus recurrence underwent a liver biopsy, TE, and MRE within 3 months of a liver biopsy. Fibrosis was assessed according to the biopsy and staged according to Metavir criteria. There was a significant correlation between both MRE and fibro-α scores, as well as histologic classification by liver biopsy (P = .02, .002). The diagnostic accuracy of MRE and fibro-α scores in diagnosing significant fibrosis (F ≥ 3) was measured as the area under the curve (.708 and .833, respectively). Both methods showed good diagnostic performance. TE and aspartate transaminase to platelet ratio index were insignificantly correlated with the degree of fibrosis in liver biopsy (P value of .134, .535). At a cutoff value of 5.5 kPa, MRE predicted graft fibrosis (Metavir stage ≥ 3) with 71.43% sensitivity, 75% specificity, 45.5% positive predictive value, and 90% negative predictive value; at a cutoff value > 1.47, fibro-α scores predicted significant graft fibrosis (Metavir stage ≥ 3) with 85.7% sensitivity and 70.83% specificity, with a positive predictive value of 46.2% and a negative predictive value of 94.4%. These data suggest that non-invasive methods could be considered a reliable tool in assessing significant graft fibrosis post-living donor liver transplantation.

The effect of operating lights on laminar flow: an experimental study using neutrally buoyant helium bubbles.

AIMS: The interaction between surgical lighting and laminar airflow is poorly understood. We undertook an experiment to identify any effect contemporary surgical lights have on laminar flow and recommend practical strategies to limit any negative effects. MATERIALS AND METHODS: Neutrally buoyant bubbles were introduced into the surgical field of a simulated setup for a routine total knee arthroplasty in a laminar flow theatre. Patterns of airflow were observed and the number of bubbles remaining above the surgical field over time identified. Five different lighting configurations were assessed. Data were analysed using simple linear regression after logarithmic transformation. RESULTS: In the absence of surgical lights, laminar airflow was observed, bubbles were cleared rapidly and did not accumulate. If lights were placed above the surgical field laminar airflow was abolished and bubbles rose from the surgical field to the lights then circulated back to the surgical field. The value of the decay parameter (slope) of the two setups differed significantly; no light (b = -1.589) versus one light (b = -0.1273, p < 0.001). Two lights touching (b = -0.1191) above the surgical field had a similar effect to that of a single light (p = 0. 2719). Two lights positioned by arms outstretched had a similar effect (b = -0.1204) to two lights touching (p = 0.998) and one light (p = 0.444). When lights were separated widely (160 cm), laminar airflow was observed but the rate of clearance of the bubbles remained slower (b = -1.1165) than with no lights present (p = 0.004). CONCLUSION: Surgical lights have a significantly negative effect on laminar airflow. Lights should be positioned as far away as practicable from the surgical field to limit this effect. Cite this article: Bone Joint J 2017;99-B:1061-6.

Are results of total knee arthroplasty for isolated patellofemoral OA as good as for medial compartment OA? A medium-term retrospective comparative study.

PURPOSE: The aim of this study was to compare the results of isolated patellofemoral arthritis (IPFA) treated using a total knee arthroplasty (TKA) compared to the results of medial tibiofemoral arthritis treated with a TKA. We hypothesised that there would be no difference between functional outcomes for the two groups. METHODS: Between 2003 and 2009, 32 TKAs were performed for IPFA (group I). Over this time period, a total of 813 primary TKAs were performed from which we identified a second group of patients who had undergone TKA for isolated medial tibiofemoral arthritis (group II: n = 32). These patients were matched based on age, sex, body mass index and average follow-up. The average age of patients in group I was 72.81 ± 6.6 years (59-83) and 71.97 ± 6.8 years in group II. The global International Knee Society (IKS) score was statistically significantly better in group I (114.72 ± 22 points) than in group II (84.9 ± 23.8). This difference was accounted for by better passive flexion, better walking distance and the absence of any coronal plane deformity. RESULTS: A total of 29 patients from group I were reviewed at an average follow-up of 64.58 ± 23.4 months, and 30 patients in group II were reviewed at an average follow-up of 66.13 ± 23.9 months (three were lost to follow-up in group I and two in group II). At final follow-up, there was statistically no difference between the two groups IKS score (175.34 ± 19.26 in group I vs. 170.13 ± 24.14 for group II) or Hospital for Special Surgery patella score (89.31 ± 9.98 points for group I vs. 89.16 ± 11.45 points for group II). We found no significant radiological difference between the two groups including patella height and orientation on axial views. CONCLUSIONS: The results of TKA for IPFA are as good as the results of TKA for isolated medial tibiofemoral arthritis with well-functioning prosthetic patellofemoral articulations. These results support our institutional preference for using TKA as treatment for IPFA in patients over 65-70 years old.

Optimizing outcome of recurrent hepatitis C virus genotype 4 after living donor liver transplantation: moving forward by looking back.

PURPOSE: Recurrence of HCV after LDLT is almost universal. Different factors affect response to treatment. Few data are available regarding outcome of recurrent HCV genotype 4. The purpose of this study is to improve outcome of recurrent HCV genotype 4 after LDLT. METHODS: An IRB approved chart review of 243 patients transplanted for ESLD, HCV genotype 4 over 4 years were reviewed. Protocol liver biopsies were taken 6 months after transplant. Patients received pegylated interferon and ribavirin in case of histological recurrence. Five patients had FCH were excluded. RESULTS: Thirty-seven patients were included. Sustained Virological Response (SVR) was achieved in 29 (78.3%). Patients with Metavir fibrosis stage (F0) and (F1) had SVR in 5/5 (100%) and 20/24 (83.3%). Two patients with F1 had to stop treatment because of thrombocytopenia and 2 were non responders. Three out of 6 patients (50%) with (F2) had SVR, 2 were non responders and one had to discontinue treatment because of severe depression. One of 2 patients (50%) with F3 had SVR and the other patient decompensated within 4 months before treatment and died. CONCLUSION: Protocol biopsies allow early detection of inflammatory changes in the graft before fibrosis occurs. Early treatment of recurrent HCV genotype 4 after LDLT results in better response.

Relevance of a press-fit dual mobility cup to deal with recurrent dislocation of conventional total hip arthroplasty: a 29-case series.

UNLABELLED: The aim of this paper was to assess the impact on stability of revision of 29 standard acetabular cups to press-fit uncemented dual mobility (DM) cups in THAs with recurrent dislocation. This series was composed of 17 women and 12 men aged on average 75.6 ± 8.1 years (55-88), operated on between November 2000 and July 2010. The average number of dislocations before revision surgery was 3.87 ± 1.79 (2-10), and the average time from primary procedure to revision was 6.6 ± 4.3 years (45-15 years). 9 patients (31.03 %) had already undergone one or more procedures for instability prior to revision to DM cup. All patients were reviewed at an average time of 46 ± 28 months (range: 17 months-11 years). Only one patient had redislocated in this time (3.4 %). This patient underwent a simple closed reduction and did not dislocate again. LEVEL OF EVIDENCE: IV retrospective cohort study.

How we estimate GFR--a pitfall of using a serum creatinine-based formula.

Chronic kidney disease (CKD) is defined using the estimated glomerular filtration rate (eGFR). This has led to a large increase in the diagnosis of CKD in the United Kingdom, the majority of which is in its earlier stages and is detected in non-hospital settings. It is important to be aware that eGFR calculations will reflect inaccuracies in the measured serum creatinine, as the latter is an important component of the calculation. We report a case in which a patient with high muscle-mass who had consumed large quantities of a creatine-containing nutritional supplement presented with apparently reduced renal function on the basis of the serum creatinine and therefore also the eGFR calculation (MDRD equation). Creatine is an amino acid which is a precursor of creatinine, and is known to transiently increase serum creatinine. 6 weeks after discontinuing creatine ingestion, serum creatinine had fallen but still gave rise to an apparently abnormal calculated eGFR. In fact, renal function was shown to be normal when estimated using 24-hour urinary creatinine clearance. This case demonstrates that the upper extreme of muscle mass and ingestion of creatine can affect not only serum creatinine but also the calculated eGFR. Knowledge of common confounding factors and their effects on serum creatinine and eGFR will allow appreciation of the limitations of these measures of renal function, and can prevent unnecessary over-investigation of such patients.