This article presents an overview of mycetoma and offers guidelines for orthopaedic surgeons who may be involved in the care of patients with this condition.

Cite this article: Bone Joint J 2014;96-B:420–5.

Objectives

Recent studies have shown that modulating inflammation-related lipid signalling after a bone fracture can accelerate healing in animal models. Specifically, decreasing 5-lipoxygenase (5-LO) activity during fracture healing increases cyclooxygenase-2 (COX-2) expression in the fracture callus, accelerates chondrogenesis and decreases healing time. In this study, we test the hypothesis that 5-LO inhibition will increase direct osteogenesis.

For the treatment of ununited fractures, we developed a system of delivering magnetic labelled mesenchymal stromal cells (MSCs) using an extracorporeal magnetic device. In this study, we transplanted ferucarbotran-labelled and luciferase-positive bone marrow-derived MSCs into a non-healing femoral fracture rat model in the presence of a magnetic field. The biological fate of the transplanted MSCs was observed using luciferase-based bioluminescence imaging and we found that the number of MSC derived photons increased from day one to day three and thereafter decreased over time. The magnetic cell delivery system induced the accumulation of photons at the fracture site, while also retaining higher photon intensity from day three to week four. Furthermore, radiological and histological findings suggested improved callus formation and endochondral ossification. We therefore believe that this delivery system may be a promising option for bone regeneration.

The purpose of this study was to evaluate the expression of acid-sensing ion channels (ASICs) in the capsule and synovial fluid of patients with frozen shoulder. Capsular tissue and synovial fluid were obtained from 18 patients with idiopathic frozen shoulder (FS group) and 18 patients with instability of the shoulder (control group). The expressions of ASIC1, ASIC2, and ASIC3 in the capsule were determined using the reverse transcriptase-polymerase chain reaction, immunoblot analysis, and immunohistochemistry (IHC). The concentrations in synovial fluid were evaluated using an enzyme-linked immunosorbent assay.

The mRNA expression of ASIC1, ASIC2 and ASIC3 in the capsule were significantly increased in the FS group compared with the control group. The protein levels of these three ASICs were also increased. The increased expressions were confirmed by IHC. Of the ASICs, ASIC3 showed the greatest increase in both mRNA and levels of expression compared with the control group. The levels of ASIC1 and ASIC3 in synovial fluid were significantly increased in the FS group.

This study suggests that ASICs may play a role as mediators of inflammatory pain and be involved in the pathogenesis of frozen shoulder.

Cite this article: Bone Joint J 2015;97-B:824–9.

This is a retrospective study of survivors of recent conflicts with an open fracture of the femur. We analysed the records of 48 patients (48 fractures) and assessed the outcome. The median follow up for 47 patients (98%) was 37 months (interquartile range 19 to 53); 31 (66%) achieved union; 16 (34%) had a revision procedure, two of which were transfemoral amputation (4%).

The New Injury Severity Score, the method of fixation, infection and the requirement for soft-tissue cover were not associated with a poor outcome. The degree of bone loss was strongly associated with a poor outcome (p = 0.00204). A total of four patients developed an infection; two with S. aureus, one with E. coli and one with A. baumannii.

This study shows that, compared with historical experience, outcomes after open fractures of the femur sustained on the battlefield are good, with no mortality and low rates of infection and late amputation. The degree of bone loss is closely associated with a poor outcome.

Cite this article: Bone Joint J 2015;97-B:842–6.

Tranexamic acid (TXA), an inhibitor of fibrinolysis, reduces blood loss after total knee arthroplasty. However, its effect on minimally invasive total hip arthroplasty (THA) is not clear. We performed a prospective, randomised double-blind study to evaluate the effect of two intravenous injections of TXA on blood loss in patients undergoing minimally invasive THA.

In total, 60 patients (35 women and 25 men with a mean age of 58.1 years; 17 to 84) who underwent unilateral minimally invasive uncemented THA were randomly divided into the study group (30 patients, 20 women and ten men with a mean age of 56.5 years; 17 to 79) that received two intravenous injections 1 g of TXA pre- and post-operatively (TXA group), and a placebo group (30 patients, 15 women and 15 men with a mean age of 59.5 years; 23 to 84). We compared the peri-operative blood loss of the two groups. Actual blood loss was calculated from the maximum reduction in the level of haemoglobin. All patients were followed clinically for the presence of venous thromboembolism.

The TXA group had a lower mean intra-operative blood loss of 441 ml (150 to 800) versus 615 ml (50 to 1580) in the placebo (p = 0.044), lower mean post-operative blood loss (285 ml (120 to 570) versus 392 ml (126 to 660) (p = 0.002), lower mean total blood loss (1070 ml (688 to 1478) versus 1337 ml (495 to 2238) (p = 0.004) and lower requirement for transfusion (p = 0.021). No patients in either group had symptoms of venous thromboembolism or wound complications.

This prospective, randomised controlled study showed that a regimen of two intravenous injections of 1 g TXA is effective for blood conservation after minimally invasive THA.

Cite this article: Bone Joint J 2015;97-B:905–10.

We used interconnected porous calcium hydroxyapatite ceramic to bridge a rabbit ulnar defect. Two weeks after inducing the defect we percutaneously injected rabbit bone marrow-derived mesenchymal stromal cells labelled with ferumoxide. The contribution of an external magnetic targeting system to attract these cells into the ceramic and their effect on subsequent bone formation were evaluated.

This technique significantly facilitated the infiltration of ferumoxide-labelled cells into ceramic and significantly contributed to the enhancement of bone formation even in the chronic phase. As such, it is potentially of clinical use to treat fractures, bone defects, delayed union and nonunion.

Objectives

There remains conflicting evidence regarding cortical bone strength following bisphosphonate therapy. As part of a study to assess the effects of bisphosphonate treatment on the healing of rat tibial fractures, the mechanical properties and radiological density of the uninjured contralateral tibia was assessed.

The April 2015 Research Roundup360 looks at: MCID in grip strength and distal radial fracture; Experiencing rehab in a trial setting; Electrical stimulation and nerve recovery; Molecular diagnosis of TB?; Acetabular orientation: component and arthritis; Analgesia after knee arthroplasty; Bisphosphonate-associated femoral fractures

The June 2012 Spine Roundup³⁶⁰ looks at: back pain; spinal fusion for tuberculosis; anatomical course of the recurrent laryngeal nerve; groin pain with normal imaging; the herniated intervertebral disc; obesity’s effect on the spine; the medicolegal risks of cauda equina syndrome; and intravenous lidocaine use and failed back surgery syndrome.

Aspiration arthrography using an iodinated contrast medium is a useful tool for the investigation of septic or aseptic loosening of arthroplasties and of septic arthritis. Previously, the contrast media have been thought to cause false negative results in cultures when present in aspirated samples of synovial fluid, probably because free iodine is bactericidal, but reports have been inconclusive.

We examined the influence of the older, high osmolar contrast agents and the low osmolar media used currently on the growth of ten different micro-organisms capable of causing deep infection around a prosthesis. Five media were tested, using a disc diffusion technique and a time-killing curve method in which high and low inocula of micro-organisms were incubated in undiluted media. The only bactericidal effects were found with low inocula of Escherichia coli and Pseudomonas aeruginosa in ioxithalamate, one of the older ionic media.

The low and iso-osmolar iodinated contrast media used currently do not impede culture. Future study must assess other causes of false negative cultures of synovial fluid and new developments in enhancing microbial recovery from aspirated samples.

Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment.

We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis.

No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm.

The April 2015 Shoulder & Elbow Roundup³⁶⁰ looks at: Distal clavicular resection not indicated in cuff repair?; Platelet-rich plasma in rotator cuff repair; Radial head geometry: time to change?; Heterotopic ossification in elbow trauma; Another look at heterotopic ossification in the humerus; Triceps on for total elbow arthroplasty?; Predicting outcomes in rotator cuff repair; Deltoid fatty infiltration and reverse shoulder arthroplasty

The December 2013 Research Roundup³⁶⁰ looks at: Inflammation implicated in FAI; Ponseti and effective teaching; Unicompartmental knee design and tibial strain; Bisphosphonates and fracture healing; Antibiosis in cement; Zoledronic acid improves primary stability in revision?; Osteoporotic fractures revisited; and electroarthrography for monitoring of cartilage degeneration

Objective

To study the effect of hyaluronic acid (HA) on local anaesthetic chondrotoxicity in vitro.

The aim of this study was to assess the effect of injecting genetically engineered chondrocytes expressing transforming growth factor beta 1 (TGF-β1) into the knees of patients with osteoarthritis. We assessed the resultant function, pain and quality of life.

A total of 54 patients (20 men, 34 women) who had a mean age of 58 years (50 to 66) were blinded and randomised (1:1) to receive a single injection of the active treatment or a placebo. We assessed post-treatment function, pain severity, physical function, quality of life and the incidence of treatment-associated adverse events. Patients were followed at four, 12 and 24 weeks after injection.

At final follow-up the treatment group had a significantly greater improvement in the mean International Knee Documentation Committee score than the placebo group (16 points; -18 to 49, vs 8 points; -4 to 37, respectively; p = 0.03). The treatment group also had a significantly improved mean visual analogue score at final follow-up (-25; -85 to 34, vs -11 points; -51 to 25, respectively; p = 0.032). Both cohorts showed an improvement in Western Ontario and McMaster Osteoarthritis Index and Knee Injury and Osteoarthritis Outcome Scores, but these differences were not statistically significant. One patient had an anaphylactic reaction to the preservation medium, but recovered within 24 hours. All other adverse events were localised and resolved without further action.

This technique may result in improved clinical outcomes, with the aim of slowing the degenerative process, leading to improvements in pain and function. However, imaging and direct observational studies are needed to verify cartilage regeneration. Nevertheless, this study provided a sufficient basis to proceed to further clinical testing.

Cite this article: Bone Joint J 2015;97-B:924–32.

Only limited data are available regarding the infiltration of local anaesthetic for total hip arthroplasty (THA), and no studies were performed for THA using the anterior approach.

In this prospective, randomised placebo-controlled study we investigated the effect of both standard and reverse infiltration of local anaesthetic in combination with the anterior approach for THA. The primary endpoint was the mean numeric rating score for pain four hours post-operatively. In addition, we recorded the length of hospital stay, the operating time, the destination of the patient at discharge, the use of pain medication, the occurrence of side effects and pain scores at various times post-operatively.

Between November 2012 and January 2014, 75 patients were included in the study. They were randomised into three groups: standard infiltration of local anaesthetic, reversed infiltration of local anaesthetic, and placebo. There was no difference in mean numeric rating score for pain four hours post-operatively (p = 0.87). There were significantly more side effects at one and eight hours post-operatively in the placebo group (p = 0.02; p = 0.03), but this did not influence the mobilisation of the patients. There were no differences in all other outcomes between the groups.

We found no clinically relevant effect when the infiltration of local anaesthetic with ropivacaine and epinephrine was used in a multimodal pain protocol for THA using the anterior approach.

Cite this article: Bone Joint J 2015; 97-B:734–40.

The February 2015 Research Roundup360 looks at: Markers of post-traumatic ankle arthritis; Mangoes, trees and Solomon Islanders; Corticosteroid injection and ulnar neuropathy; Moral decision-making: the secret skill?; Biomechanical studies under the spotlight; Anaesthetic risk and hip replacement

Compartment syndrome, a devastating consequence of limb trauma, is characterised by severe tissue injury and microvascular perfusion deficits. We hypothesised that leucopenia might provide significant protection against microvascular dysfunction and preserve tissue viability. Using our clinically relevant rat model of compartment syndrome, microvascular perfusion and tissue injury were directly visualised by intravital video microscopy in leucopenic animals. We found that while the tissue perfusion was similar in both groups (38.8% (standard error of the mean (sem) 7.1), 36.4% (sem 5.7), 32.0% (sem 1.7), and 30.5% (sem 5.35) continuously-perfused capillaries at 45, 90, 120 and 180 minutes compartment syndrome, respectively versus 39.2% (sem 8.6), 43.5% (sem 8.5), 36.6% (sem 1.4) and 50.8% (sem 4.8) at 45, 90, 120 and 180 minutes compartment syndrome, respectively in leucopenia), compartment syndrome-associated muscle injury was significantly decreased in leucopenic animals (7.0% (sem 2.0), 7.0%, (sem 1.0), 9.0% (sem 1.0) and 5.0% (sem 2.0) at 45, 90, 120 and 180 minutes of compartment syndrome, respectively in leucopenia group versus 18.0% (sem 4.0), 23.0% (sem 4.0), 32.0% (sem 7.0), and 20.0% (sem 5.0) at 45, 90, 120 and 180 minutes of compartment syndrome in control, p = 0.0005). This study demonstrates that the inflammatory process should be considered central to the understanding of the pathogenesis of cellular injury in compartment syndrome.

Cite this article: Bone Joint J 2015;97-B:539–43

We hypothesised that a minimally invasive peroneus brevis tendon transfer would be effective for the management of a chronic rupture of the Achilles tendon. In 17 patients (three women, 14 men) who underwent minimally invasive transfer and tenodesis of the peroneus brevis to the calcaneum, at a mean follow-up of 4.6 years (2 to 7) the modified Achilles tendon total rupture score (ATRS) was recorded and the maximum circumference of the calf of the operated and contralateral limbs was measured. The strength of isometric plantar flexion of the gastrocsoleus complex and of eversion of the ankle were measured bilaterally. Functional outcomes were classified according to the four-point Boyden scale.

At the latest review, the mean maximum circumference of the calf of the operated limb was not significantly different from the pre-operative mean value, (41.4 cm, 32 to 50 vs 40.6 cm, 33 to 46; p = 0.45), and not significantly less than that of the contralateral limb (43.1 cm, 35 to 52; p = 0.16). The mean peak torque (244.6 N, 125 to 367) and the strength of eversion of the operated ankle (149.1 N, 65 to 240) were significantly lower (p < 0.01) than those of the contralateral limb (mean peak torque 289, 145 to 419; strength of eversion: 175.2, 71 to 280). The mean ATRS significantly improved from 58 pre-operatively (35 to 68) to 91 (75 to 97; 95% confidence interval 85.3 to 93.2) at the time of final review. Of 13 patients who practised sport at the time of injury, ten still undertook recreational activities.

This procedure may be safely performed, is minimally invasive, and allows most patients to return to pre-injury sport and daily activities.

Cite this article: Bone Joint J 2015;97-B:353–7.