Utility of tibial tubercle osteotomy in the setting of periprosthetic infection after total knee arthroplasty

Purpose

This study reports radiographic and clinical treatment outcomes of tibial tubercle osteotomy (TTO) used for two-stage revision total knee arthroplasty (TKA) in the setting of periprosthetic infection.

Methods

Thirty-six patients with 51 TTOs used for infected TKA were retrospectively analysed from 2000 to 2010. In 15 of 36 patients, TTO was used in a sequential manner during both first and second stage procedures. The mean follow-up period was 57?months (range seven–126?months).

Results

The mean pre-operative range of knee motion was 40° (range 10–90°), and at latest follow-up it was 92° (range 50–140°). The Knee Society knee scores and function scores were 47 and 9 pre-operatively and 82 and 72 at latest follow-up, respectively. Bony union was achieved in all cases except one nonunion of an avulsion fragment of the osteotomy segment without functional deterioration.

Conclusions

TTO can be a useful extensile surgical approach for treatment of infected TKA with satisfactory clinical and radiographic outcomes.     

A Swedish consensus on the surgical treatment of concomitant atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia among patients scheduled for open heart surgery and is associated with increased morbidity and mortality. According to international guidelines, symptomatic and selected asymptomatic patients should be offered concomitant surgical AF ablation in conjunction with valvular or coronary surgery. The gold standard in AF surgery is the Cox Maze III ("cut-and-sew") procedure, with surgical incisions in both atria according to a specified pattern, in order to prevent AF reentry circuits from developing. Over 90% of patients treated with the Cox Maze III procedure are free of AF after 1 year. Recent developments in ablation technology have introduced several energy sources capable of creating nonconducting atrial wall lesions. In addition, simplified lesion patterns have been suggested, but results with these techniques have been unsatisfactory. There is a clear need for standardization in AF surgery. The Swedish Arrhythmia Surgery Group, represented by surgeons from all Swedish units for cardiothoracic surgery, has therefore reached a consensus on surgical treatment of concomitant AF. This consensus emphasizes adherence to the lesion pattern in the Cox Maze III procedure and the use of biatrial lesions in nonparoxysmal AF.     

Is Laparoscopic Colorectal Cancer Surgery in Obese Patients Associated with an Increased Risk? Short-Term Results from a Single Center Study of 425 Patients

Introduction

In laparoscopic colorectal cancer surgery, some authors still report increased conversion rates, operative duration and postoperative morbidity with longer hospital stay in obese patients. In our department, we had the impression that laparoscopic surgery in the obese was feasible and safe, leading to this study in which we evaluate laparoscopic surgery for colorectal cancers in the obese and measure the impact on short-term results.

Material and Methods

In the period from November 2004 to May 2010, 425 patients were laparoscopically operated for a colon or rectal cancer in our center. Ninety-three patients had a body mass index (BMI)????30. Demographic data and short-term outcome in patients with a BMI????30 were compared to the same data in patients with a BMI?<?30.

Results

The median operative time was significantly longer (240 vs. 225?min, p?=?0.021) and the mean blood loss was significantly higher (348 vs. 285?ml, p?=?0.034) in the group of patients with BMI????30. No other significant differences, including conversion to open surgery and postoperative morbidity, were found between the two groups.

Conclusion

Laparoscopic colorectal cancer surgery is feasible and safe in obese patients with a BMI above 30, without the patients experiencing an increased risk of postoperative morbidity or mortality.     

Frequency of blood lactate elevation following esophagectomy and its association to postoperative complications

Background

Esophagectomy is a major surgical intervention and a cornerstone in the treatment of esophageal cancer. There is clinical experience that blood lactate concentration often is elevated in the period following esophagectomy, but the incidence and clinical consequences are sparsely studied.

Methods

We extracted data from all patients undergoing esophagectomy at Karolinska University Hospital 2016–2018, n = 153. Most were performed with minimally invasive technique, n = 130. Blood lactate values directly after surgery, highest value during the first night, and morning level on postoperative day one were recorded. Primary outcome was hospital length of stay and secondary outcome was a composite of postoperative infection, additional surgery, or intensive care during the hospital stay. Development of anastomotic leak was analyzed separately.

Results

Postoperative hyperlactatemia was common as 93% of patients had peak lactate concentration >1.6 mmol/L and 27% >3.5 mmol/L in the first night following operation. Median hospital length of stay was 14 days. Blood lactate showed a weak correlation to hospital stay and intensive care the morning following surgery, but not at arrival to postoperative ward. There were no statistical differences between those with and without anastomotic leak at any of the time points. Elevated lactate in the first 12–16 h postoperatively was related to surgical factors (open technique, surgery time, and perioperative bleeding) but not to patient related factors (ASA-class, Charlson comorbidity index, sex, age) or cumulative fluid balance.

Conclusion

In conclusion, elevated blood lactate in the immediate time following esophagectomy showed a weak association to intensive care and length of stay but not anastomotic leak.     

In vivo sodium (23Na) imaging of the human kidneys at 7 T: Preliminary results

Objective

To evaluate the feasibility of in vivo ²³Na imaging of the corticomedullary ²³Na gradient and to measure ²³Na transverse relaxation times (T2*) in human kidneys.

Methods

In this prospective, IRB-approved study, eight healthy volunteers (4 female, 4 male; mean age 29.4?±?3.6 years) were examined on a 7-T whole-body MR system using a ²³Na-only spine-array coil. For morphological ²³Na-MRI, a 3D gradient echo (GRE) sequence with a variable echo time scheme (vTE) was used. T2* times were calculated using a multiecho 3D vTE-GRE approach. ²³Na signal-to-noise ratios (SNR) were given on a pixel-by-pixel basis for a 20-mm section from the cortex in the direction of the medulla. T2* maps were calculated by fitting the ²³Na signal decay monoexponentially on a pixel-by-pixel basis, using least squares fit.

Results

Mean corticomedullary ²³Na-SNR increased from the cortex (32.2?±?5.6) towards the medulla (85.7?±?16.0). The SNR increase ranged interindividually from 57.2 % to 66.3 %. Mean ²³Na-T2* relaxation times differed statistically significantly (P?<?0.001) between the cortex (17.9?±?0.8 ms) and medulla (20.6?±?1.0 ms).

Conclusion

The aim of this study was to evaluate the feasibility of in vivo ²³Na MRI of the corticomedullary ²³Na gradient and to measure the ²³Na T2* relaxation times of human kidneys at 7 T.

Key Points

? High field MR offers new insights into renal anatomy and physiology. ? ²³ Na MRI of healthy human kidneys is feasible at ultra-high field. ? Renal ²³ Na concentration increases from the cortex in the medullary pyramid direction. ? In vivo measurements of renal ²³ Na-T2* times are demonstrated at 7.0 T.     

Antagonism of atracurium-induced block in obese patients

Purpose

To investigate the relationship between total body weight (TBW) or body mass index (BMI) and atracurium reversal time.

Methods

The study population comprised 25 patients with TBW < 80 kg and 25 patients with TBW ≥80 kg anaesthetised with midazolam, thiopentone, fentanyl, nitrous oxide and halothane. Neuromuscular block was induced with 0.5 mg· kg^?1 atracurium and maintained with doses of 0.15 mg· kg^?1. Neuromuscular transmission was recorded using train-of-four (TOF) nerve stimulation and mechanomyography. Neostigmine, 0.07 mg· kg^?1, was administered when the first twitch in TOF had recovered to 10% of control. Reversal time was defined as: time from administration of neostigmine until TOF ratio recovered to 0.70.

Results

There was no difference in reversal time between patients with TBW < 80 kg (7.2 ± 2.6 min, mean ± SD), and patients with TBW ≥80 kg (6.9 ± 3.6 min). When patients were grouped according to BMI there was no difference in reversal time between groups with low BMI (6.9 ± 2.6 min) or high BMI (7.1 ± 3.6 min). There was, furthermore, no difference in reversal time between the 15 patients in the study population with the smallest TBW or BMI and the 15 patients with the greatest TBW or BMI. There was no correlation between TBW or BMI and reversal time.

Conclusion

When atracurium-induced neuromuscular block is antagonised with 0.07 mg· kg^?1 neostigmine, TBW or BMI have no influence on reversal time.     

Prevention of severe contractures might replace multilevel surgery in cerebral palsy: results of a population-based health care programme and new techniques to reduce spasticity

During the 1990s three new techniques to reduce spasticity and dystonia in children with cerebral palsy (CP) were introduced in southern Sweden: selective dorsal rhizotomy, continuous intrathecal baclofen infusion and botulinum toxin treatment. In 1994 a CP register and a health care programme, aimed to prevent hip dislocation and severe contractures, were initiated in the area. The total population of children with CP born 1990-1991, 1992-1993 and 1994-1995 was evaluated and compared at 8 years of age. In non-ambulant children the passive range of motion in hip, knee and ankle improved significantly from the first to the later age groups. Ambulant children had similar range of motion in the three age groups, with almost no severe contractures. The proportion of children treated with orthopaedic surgery for contracture or skeletal torsion deformity decreased from 40 to 15% (P = 0.0019). One-fifth of the children with spastic diplegia had been treated with selective dorsal rhizotomy. One-third of the children born 1994-1995 had been treated with botulinum toxin before 8 years of age. With early treatment of spasticity, early non-operative treatment of contracture and prevention of hip dislocation, the need for orthopaedic surgery for contracture or torsion deformity is reduced, and the need for multilevel procedures seems to be eliminated.     

Cost consequences due to reduced ulcer healing times – analyses based on the Swedish Registry of Ulcer Treatment

Resource use and costs for topical treatment of hard‐to‐heal ulcers based on data from the Swedish Registry of Ulcer Treatment (RUT) were analysed in patients recorded in RUT as having healed between 2009 and 2012, in order to estimate potential cost savings from reductions in frequency of dressing changes and healing times. RUT is used to capture areas of improvement in ulcer care and to enable structured wound management by registering patients with hard‐to‐heal leg, foot and pressure ulcers. Patients included in the registry are treated in primary care, community care, private care, and inpatient hospital care. Cost calculations were based on resource use data on healing time and frequency of dressing changes in Swedish patients with hard‐to‐heal ulcers who healed between 2009 and 2012. Per‐patient treatment costs decreased from SEK38 223 in 2009 to SEK20 496 in 2012, mainly because of shorter healing times. Frequency of dressing changes was essentially the same during these years, varying from 1·4 to 1·6 per week. The total healing time was reduced by 38%. Treatment costs for the management of hard‐to‐heal ulcers can be reduced with well‐developed treatment strategies resulting in shortened healing times as shown in RUT.     

Use of a virtual reality, real-time, simulation model for the training of urologists in transurethral resection of the prostate

OBJECTIVE: There is a growing need to develop surgical skills outside the operating theatre. In this study we describe the development of a virtual reality training system for practising transurethral resection of the prostate (TURP). MATERIAL AND METHODS: A face validity study was performed using a questionnaire sent to 28 experienced urologists to find out the ideal characteristics of a simulated TURP. Based on the comments a simulator was constructed and a content validity study was then performed in which nine experienced urologists tested the simulator and answered a second questionnaire. After corrections to the simulator, a basic construct validity test was performed. RESULTS: We have developed a computer-based simulator based on the requirements listed by 17 urologists. It consists of a modified resectoscope connected to a haptic device and supported by a frame. The software provides a virtual view of the prostatic lumen and resectoscope tip, a haptic rendering that generates force feedback and a simulation module that computes the information from the haptic device, resectoscope fluid tap and handle and the foot pedals. The software also simulates bleeding, absorption of irrigation fluid and pressure gradients. Variables are measured and presented in a result file after each "operation". Nine experienced urologists performed a content validity study and changes were made accordingly. A basic construct validity test performed by seven inexperienced students showed a significant improvement in performance after they each performed six simulated procedures. CONCLUSION: We have developed a simulator that may be used to practise TURP and which meets most of the demands raised in a face validity study. A basic construct validity test showed improved performance after repeated practice in the simulated environment.