Compacted cancellous bone has a spring-back effect

A new surgical technique, compaction, has been shown to improve implant fixation. It has been speculated that the enhanced implant fixation with compaction could be due to a spring-back effect of compacted bone. However, such an effect has yet to be shown. Therefore we investigated in a canine model whether implant cavities prepared with compaction had spring back. Before killing the animals, we used one of two surgical techniques to make implant cavities of identical dimensions in both lateral femoral condyles of 7 dogs. One side had the implant cavity prepared with compaction, the other side with drilling. The cavities were left empty in vivo for 10 minutes before the dogs were killed. Postoperative micro-CT scanning showed that the diameters of the compacted cavities were significantly smaller than those of the drilled cavities, although they had had identical dimensions initially. Thus we found a spring-back effect of compacted bone, which may be important for increasing implant fixation by reducing initial gaps between the implant and bone.     

A retrospective analysis of medial opening wedge high tibial osteotomy for varus osteoarthritic knee

Background:

Medial opening wedge high tibial osteotomy (MOWHTO) has proven to be an effective treatment for varus osteoarthritic knees. Various methods of fixation with different implant types and using either bone grafts or bone substitutes have been reported. We performed non-locking T-buttress plate fixation with autologous iliac bone graft augmentation, which is defined here as the traditional method, and locking compression plate fixation without any bone graft or bone substitute. We aimed to compare bone union and complications of these two MOWHTO techniques.

Materials and Methods:

Between June 2005 and December 2007, 50 patients who underwent MOWHTO (a total of 60 knees) were retrospectively reviewed and classified into two groups: group A, which consisted of 26 patients (30 knees) was treated using T-buttress plate fixation with autologous iliac bone graft augmentation and group B, which consisted of 24 patients (30 knees) was operated upon using a medial high tibial locking compression plate without any augmentation. Demographic characteristics and radiographic outcomes, including union rate, time to union, medial osteotomy defects, and complications, were collected and compared between the two groups. The progress of all patients was followed for at least 2 years.

Results:

All osteotomies united within 12 weeks after surgery. Group B had slightly longer time to union than group A (10.3 weeks and 9.5 weeks, respectively; P = 0.125). A significantly higher incidence of medial defects after osteotomy was reported in the locking compression plate group (P = 0.001). A total of 5 (8.3%) knees had complications. In group A, one knee had a superficial wound infection and another knee had a lateral tibial plateau fracture without significant loss of correction. In group B, one knee had screw penetration into the knee joint and two knees had local irritation that required the removal of the hardware.

Conclusion:

Locking compression plate fixation without the use of bone grafts or bone substitutes provides a satisfactory union rate and an acceptable complication rate when compared to the traditional MOWHTO technique. Thus, we recommend using this technique for treating unicompartmental medial knee osteoarthritis.     

Three-hour interval drain clamping reduces postoperative bleeding in total knee arthroplasty: a prospective randomized controlled trial

Background

Total knee arthroplasty (TKA) is a common procedure that has a risk of significant blood loss and blood transfusion, and carries a substantial risk for immunologic reactions and disease transmission. Drain clamping is a popular method that is applied to reduce blood loss after TKA. However, the clamping protocol remains controversial. Therefore, we established a new protocol, 3-h interval clamping, and compared the bleeding control efficacy of this protocol following TKA with the non-clamping technique.

Methods

Between March and July 2008, we enrolled 100 patients (100 knees) who underwent uncomplicated TKA using a minimally invasive surgical technique. The patients were randomly assigned into two groups based on the draining protocol: non-clamping (group A) and 3-h interval clamping (group B). For group A, a vacuum drain was connected to a container and was run continuously during the first postoperative day, whereas the vacuum was stopped twice (for ~3 h each time) for group B. Demographic characteristics and clinical data were collected, including the levels of hemoglobin and hematocrit, the total blood loss volume, the number of patients who required a blood transfusion, and any complications that developed. The perioperative data were compared between the two groups.

Results

The drainage blood volume in the interval-clamping group (group B) was significantly lower than that in the non-clamping group (group A) during the first 48 h following the procedure (p < 0.001 and p = 0.005 for first and second postoperative days, respectively). The mean fall in hemoglobin levels at 12 h in the interval-clamping group (2.8 ± 0.9 g/dL) was also lower than in the non-clamping group (3.2 ± 0.8 g/dL). In the 3-h interval clamping protocol, the number of patients requiring a transfusion was 2.2 times less than the number in the non-clamping protocol, but was not significantly different (odds ratio = 2.20, p = 0.24), and the significant predictor of blood transfusion was the preoperative hemoglobin level (odds ratio = 7.73, p < 0.001). No wound infection or clinical venous thromboembolisms were detected in our study.

Conclusion

The 3-h interval clamping is a newly developed protocol for reducing blood loss after TKA. The protocol lessens the decrease in postoperative hemoglobin levels. This protocol can be applied easily without increasing clinical thromboembolic events and wound complications.     

Treatment of congenital dislocated hip by arthroplasty with femoral shortening

This was a retrospective study of 15 hips in 11 patients with complete congenital dislocation of the hip treated by total hip arthroplasty and femoral shortening with a subtrochanteric double chevron derotation osteotomy. The mean age at the time of surgery was 51 years (range, 21-74 years), and the mean followup was 5.5 years (range, 2-8.5 years). Functional evaluation using the modified Harris hip rating system showed an excellent result in five hips and a good result in seven hips (80% success rate). The location of the hip center was lowered by a mean of 8.3 cm (range, 5.7-10.4 cm). Leg length discrepancy in seven patients with unilateral involvement was reduced from a mean of 3.9 cm (range, 1.7-8.2 cm) before surgery to a mean of 1.4 cm at the latest followup (range, 0-4 cm). The Trendelenburg sign was assessed in 10 of 15 hips and was corrected from a positive preoperative status to a negative postoperative status in eight of these 10 hips. There were no cases of nonunion, dislocation, nerve palsy, or radiographic loosening. The only complications were a supracondylar fracture below the femoral component in a patient with severe osteoporosis 6 months after surgery and loosening of the cemented titanium metal backed acetabular component in the same patient 1.5 years after surgery. The current series showed that total hip arthroplasty in combination with a subtrochanteric double chevron derotation osteotomy has promising short to midterm results in the treatment of complete congenital dislocation of the hip in adults.     

Role of Gastrointestinal Microbiota on Kidney Injury and the Obese Condition

Obesity is associated with kidney disease, probably due to obesity-mediated inflammation, podocyte injury and oxidative stress in the kidney It is also linked to other diseases, for example, diabetes and hypertension, which are associated with the development and progression of chronic kidney disease. Interestingly, gastrointestinal dysbiosis has been demonstrated in cases of obesity with the development and progression of kidney disease. Thus, modification of gastrointestinal microbiota using probiotics or prebiotics or both to improve the balance of bacterial flora is a potential approach for the management of obesity-associated kidney disease. This review covers information regarding the association between obesity and kidney injury, and it examines evidence for a hypothesized role of gastrointestinal microbiota in this setting. Studies describing the effects of probiotic and prebiotic treatments on kidney disease show mixed results, although several suggest benefits indicated by biomarkers associated with kidney injury, uremia and inflammation. Additional studies are needed to determine whether these interventions are clinically effective in managing kidney injury and kidney disease.     

Response surface optimization of enzymatic hydrolysis and ROS scavenging activity of silk sericin hydrolysates

ContextSericin, a protein found in wastewater from the silk industry, was shown to contain a variety of biological activities, including antioxidant. The enzymatic conditions have been continuously modified to improve antioxidant effect and scavenging capacity against various free radicals of silk sericin protein.ObjectiveVariables in enzymatic reactions, including pH, temperature and enzyme/substrate ratio were analysed to discover the optimum conditions for antioxidant activity of sericin hydrolysates.Materials and methodsHydrolysis reaction catalysed by Alcalase^® was optimized through response surface methodology (RSM) in order to generate sericin hydrolysates possessing potency for % inhibition on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, ferric-reducing power and peroxyl scavenging capacity. Flow cytometry was performed to evaluate cellular ROS level in human HaCaT keratinocytes and melanin-generating MNT1 cells pre-treated either with 20 mg/mL RSM-optimized sericin hydrolysates or 5 mM N-acetyl cysteine (NAC) for 60 min prior exposure with 1 mM hydrogen peroxide (H₂O₂).ResultsAmong these three variables, response surface plots demonstrate the major role of temperature on scavenging capacity of sericin hydrolysates. Sericin hydrolysates prepared by using Alcalase^® at RSM-optimized condition (enzyme/substrate ratio: 1.5, pH: 7.5, temperature: 70 °C) possessed % inhibition against H₂O₂ at 99.11 ± 0.54% and 73.25 ± 8.32% in HaCaT and MNT1 cells, respectively, while pre-treatment with NAC indicated the % inhibition only at 30.26 ± 7.62% in HaCaT and 51.05 ± 7.14% in MNT1 cells.Discussion and conclusionsThe acquired RSM information would be of benefit for further developing antioxidant peptide from diverse resources, especially the recycling of waste products from silk industry.     

Increased cartilage volume after injection of hyaluronic acid in osteoarthritis knee patients who underwent high tibial osteotomy

Purpose

High tibial osteotomy (HTO) is a surgical procedure used to correct abnormal mechanical loading of the knee joint; additionally, intra-articular hyaluronic acid injections have been shown to restore the viscoelastic properties of synovial fluid and balance abnormal biochemical processes. It was hypothesized that combining HTO with intra-articular hyaluronic acid injections would have benefit to improve the cartilage volume of knee joints.

Methods

Forty patients with medial compartment knee osteoarthritis (OA) were randomly placed into 1 of 2 groups. The study group (n = 20) received 2 cycles (at 6-month intervals) of 5 weekly intra-articular hyaluronic acid injections after HTO operation. The control group (n = 20) did not receive any intra-articular injections after HTO surgery. Cartilage volume (primary outcome) was assessed by magnetic resonance imaging (MRI) pre-operatively and 1 year post-operatively. Treatment efficacy (secondary outcomes) was evaluated with the Western Ontario and McMaster Universities OA Index (WOMAC) and by the comparison of the total rescue medication (paracetamol/diclofenac) used (weeks 6, 12, 24, 48).

Results

MRI studies showed a significant increase in total cartilage volume (p = 0.033), lateral femoral cartilage volume (p = 0.044) and lateral tibial cartilage volume (p = 0.027) in the study group. Cartilage volume loss was detected at the lateral tibial plateau in the control group. There were significant improvements after surgery in both groups for all subscales of WOMAC scores (p < 0.001) compared to the baseline. However, no difference was found between the two groups. The study group had significantly lower amounts of diclofenac consumption (p = 0.017).

Conclusion

Based on the findings of the present study, intra-articular hyaluronic acid injections may be beneficial for increasing total cartilage volume and preventing the loss of lateral tibiofemoral joint cartilage after HTO.

Level of evidence

Therapeutic study, Level I.