Aim. Orthopedic implants play a tremendous role in fixing bone damages due to aging as well as fractures. However, these implants tend to get colonized by bacteria on the surface, leading to infections and subsequently prevention of healing and osteointegration. Recently, Roupie et al. showed that a nisin layer-by-layer based coating applied on biomaterials has both osteogenic and antibacterial properties. The Galleria mellonella larva is a well-known insect infection model that has been used to test the virulence of bacterial and fungal strains as well as for the high throughput screening of antimicrobial compounds against infections. Recently, we have developed an insect infection model with G. mellonella larvae to study implant-associated biofilm infections using Kirschner (K)-wires as implant material. Here, we would like to test the antibacterial capacity of nisin layer-by-layer based coatings on K-wires against Staphylococcus aureus in the G. mellonella larva implant infection model. Method. Prior to the implantation procedure, G. mellonella larvae are maintained at room temperature on wheat germ in an incubator. The larvae received bare titanium K-wires (uncoated), or either control-coated or nisin-coated K-wires. After one hour, the larvae were injected with 5×10. 5. S. aureus bacteria per larva (i.e., hematogenous implant infection model). Next, the larvae were incubated at 37. o. C in an incubator and the survival of the larvae was monitored for five days. Moreover, the number of bacteria on the implant surface and in the surrounding tissue was determined after 24h of incubation. Further, scanning electron microscopy (SEM) analyses were performed to study the effect of nisin on biofilm formation. Results. The larvae receiving the nisin-coated K-wires showed significantly higher survival rates compared to uncoated titanium K-wires, although not when compared to control-coated K-wires. A more than 1-log reduction in number of bacteria on the implant surface and in the surrounding tissue was observed in larvae receiving the nisin-coated K-wires, when compared to uncoated titanium K-wires SEM analysis showed reduced colonization of the bacteria nisin-coated K-wires compared to the controls. Conclusions. In conclusion, the antimicrobial nisin layer-by-layer based coating applied on titanium surfaces is able to prevent implant-related S. aureus biofilm infection in G. mellonella and is a promising antimicrobial strategy to prevent implant-related infections

Distal interphalangeal joint (DIPJ) fusion using a k-wire has been the gold standard treatment for DIPJ arthritis. Recent studies have shown similar patient outcomes with the headless compression screws (HCS), however there has been no cost analysis to compare the two. Therefore, this study aims to 1) review the cost of DIPJ fusion between k-wire and HCS 2) compare functional outcome and patient satisfaction between the two groups. A retrospective review was performed over a nine-year period from 2012-2021 in Counties Manukau. Cost analysis was performed between patients who underwent DIPJ fusion with either HCS or k-wire. Costs included were surgical cost, repeat operations and follow-up clinic costs. The difference in pre-operative and post-operative functional and pain scores were also compared using the patient rate wrist/hand evaluation (PRWHE). Of the 85 eligible patients, 49 underwent fusion with k-wires and 36 had HCS. The overall cost was significantly lower in the HCS group which was 6554 New Zealand Dollars (NZD), whereas this was 10408 NZD in the k-wire group (p<0.0001). The adjusted relative risk of 1.3 indicate that the cost of k-wires is 1.3 times more than HCS (P=0.0053). The patients’ post-operative PRWHE pain (−22 vs −18, p<0.0001) and functional scores (−38 vs −36, p<0.0001) improved significantly in HCS group compared to the k-wire group. Literatures have shown similar DIPJ fusion outcomes between k-wire and HCS. K-wires often need to be removed post-operatively due to the metalware irritation. This leads to more surgical procedures and clinic follow-ups, which overall increases the cost of DIPJ fusion with k-wires. DIPJ fusion with HCS is a more cost-effective with a lower surgical and follow-up costs compared to the k-wiring technique. Patients with HCS also tend to have a significant improvement in post-operative pain and functional scores

Introduction: The majority of forearm fractures in children can be managed with a plaster cast alone and manipulation under anaesthetic as required. A small number of cases however require surgical intervention. A variety of methods are available but the use of elastic intramedullary nails is becoming the technique of choice. Method: We present a two-centre study assessing the outcome of either Elastic StabJe Intramedullary Nails (ESIN) or Kirschner wires as the method of fracture stabilisation in diaphyseal forearm fractures of the radius and ulna. Results: ESIN group: 24 children underwent ESIN fixation. There were 22 boys and 2 girls, mean age 9.4 years (1.4–15.2 years, p=O.ll). Indications for stabilisation included 21 cases for fracture instability (immediate or delayed,) 2 irreducible fractures and 1 open fracture. 14 children underwent surgery on the day they sustained their fracture. The remainder were operated on an average 6.5 days following injury (1–14 days). In the K wire group: 36 children underwent K-wires fixation with 2.5mrn wires. There were 21 boys and 15 girls, mean age 10.6 years (2.2–15.5 years). Indication for stabilisation included 22 cases for fracture instability , 6 irreducible fractures and 8 open fractures. 32 children underwent surgery on the day they sustained their fracture. The remaining 4 patients were operated on the following day. Conclusions: All fractures united with no resultant subjective disability. The complication rate following K-wires was 16% and that following nail fixation 9%. Loss of forearm rotation was documented in 4 children in the K-wire group and 3 children stabilised with nails. These results confirm an excellent outcome following intramedullary fixation. We have demonstrated no difference in outcome between K-wires and ESIN, although the elastic nails do offer some theoretical advantages

Aims. Describe a statistical and economic analysis plan for the Distal Radius Acute Fracture Fixation Trial 2 (DRAFFT2) randomized controlled trial. Methods. DRAFFT2 is a multicentre, parallel, two-arm randomized controlled trial. It compares surgical fixation with K-wires versus plaster cast in adult patients who have sustained a dorsally displaced fracture of the distal radius. The primary outcome measure is the Patient-Rated Wrist Evaluation (PRWE, a validated assessment of wrist function and pain) at 12 months post-randomization. Secondary outcomes are measured at three, six, and 12 months after randomization and include the PWRE, EuroQoL EQ-5D-5L index and EQ-VAS (visual analogue scale), complication rate, and cost-effectiveness of the treatment. Results. This paper describes the full details of the planned methods of analysis and descriptive statistics. The DRAFFT2 study protocol has been published previously. Conclusion. The planned analysis strategy described records our intent to conduct statistical and within-trial cost-utility analyses. Cite this article: Bone Joint Open 2020;1-6:245–252

Purpose: To determine if oral midazolam reduces the anxiety of children undergoing removal of percutaneous Kirschner wires (K-wires) from the distal humerus in the Orthopaedic Outpatient Department. Methods: This was a prospective double blind, randomised controlled trial. 46 children aged between 3 and 12 years who had supracondylar fractures of the distal humerus internally fixed with K-wires were randomised into 2 groups. 0.2mg/kg oral midazolam (active group) or the same volume of an oral placebo (control group) was administered 30 minutes prior to removal of K-wires. Venham Situational Anxiety Score was performed before and immediately after removal of K-wires. University College London Hospital sedation score was recorded every 20 minutes. Results: 42 children with an average age of 7.1 years (range 3.6–12.3 years) had complete documentation for analysis. The two groups had similar demographics. All wires were removed in the clinic with or without midazolam. There was no significant difference in anxiety scores between the groups either before or after wire removal. The change in scores was not significantly different between the 2 groups. However, 45% of children in the active group had reduced anxiety levels in the active group compared to 18% of children given placebo but this difference was not significant (p=0.102). No child was excessively sedated but one in the active group became agitated and restless. Conclusions: The anxiety scores before and after wire removal in the active group were not significantly different from the placebo group scores. We do not recommend the routine administration of midazolam (0.2 mg/kg) to all children requiring k-wire removal in the outpatient department

Our purpose wasto determine if oral midazolam reduces the anxiety of children undergoing removal of percutaneous Kirschner wires (K-wires) from the distal humerus in the Orthopaedic Outpatient Department. This was a prospective double blind, randomised controlled trial. 46 children aged between 3 and 12 years who had supracondylar fractures of the distal humerus internally fixed with K-wires were randomised into 2 groups. 0.2mg/kg oral midazolam (active group) or the same volume of an oral placebo (control group) was administered 30 minutes prior to removal of K-wires. Venham Situational Anxiety Score was performed before and immediately after removal of K-wires. University College London Hospital sedation score was recorded every 20 minutes. 42 children with an average age of 7.1 years (range 3.6–12.3 years) had complete documentation for analysis. The two groups had similar demographics. All wires were removed in the clinic with or without midazolam. There was no significant difference in anxiety scores between the groups either before or after wire removal. The change in scores was not significantly different between the 2 groups. However, 45% of children in the active group had reduced anxiety levels in the active group compared to 18% of children given placebo but this difference was not significant (p=0.102). No child was excessively sedated but one in the active group became agitated and restless. The anxiety scores before and after wire removal in the active group were not significantly different from the placebo group scores. We do not recommend the routine administration of midazolam (0.2 mg/kg) to all children requiring k-wire removal in the outpatient department

Introduction: There remains little evidence to discern whether K-wires or screws have different outcomes in the management of lateral condylar mass (LCM) fractures in children. We studied 77 displaced (Jacob types II and III) fractures of the lateral humeral condyle in 77 children in order to infer the relative benefit of one strategy over another. Materials and methods: Between 1995 and 2005, we identified 77 LCM fractures in the departmental database. Information was collected from theatre-charts, casenotes and radiographs. We analysed demographic data, fracture features, treatment modalities, complications, and clinical and radiographic results. We excluded all complex LCM associated with elbow dislocations, olecranon fractures and bi-condylar fractures. The mean follow-up was 5.3 months (range, 6 weeks to 3 years). Results: We reviewed the results of screw osteosynthesis (n=44) versus K-wire (n=33) at an average age of 5.3 years (range, 8 months to 10.9 years). There were 49 boys and 28 girls. The average interval between the injury and the operation was 1.6 days. The mean duration of implant removal was 3.6 weeks (for K-wires, removed without anaesthesia) and 20.7 weeks (for screws, removed under general anaesthesia). There was no non-union in this series. None of the patient needed a revision of osteosynthesis. Superficial wound infection (all K-wires) was found in three patients, which was completely settled with antibiotic therapy. One patient had cubitus valgus deformity (screw), which required a corrective osteotomy. Loss of range of motion of 10–50° was found in 6 cases (3 in each group). Conclusions: Based on our observations, we believe that K-wire fixation had comparatively similar outcome to screw fixation, although, this necessitates a second procedure for removal of screw

Purpose. To elucidate whether there is an advantage in external fixation supplementation of K-wires in comparison to K-wires and plaster, in the treatment of distal radius fractures without metaphyseal comminution. Indications. Distal intraarticular radius fractures, Frykman VIII or VIII without metaphyseal comminution. Contraindications. Metaphyseal comminution, general medical contraindications for surgical intervention. Study design. Fifty-one patients were prospectively randomised in two groups: 24 patients were treated with K-wire and spanning external fixation supplementation, and 27 were treated with K-wires and plaster. Results. Patients were monitored following the operation with a minimum follow up of 1 year, and checked independently of surgeon for pain, satisfaction and range of motion. There was a statistically significant difference in favour of the external fixation patient group for pain (Visual Analogue Score, Ex-Fix group: mean 14.9, plaster group: mean 28.1, p<0.001) and satisfaction (Ex-Fix group: mean 89.7, plaster group: mean 76.3, p<0.001,). Although one would expect that range of motion would be reduced in the external fixation group, there were no statistically significant differences found in favour of plaster; on the contrary supination results were surprisingly in favour of the external fixation group (Ex-Fix group: mean 54.4, plaster group: mean 45.2, p<0.05). Conclusion. In this study, external fixation supplementation of K-wiring had statistically significant superior results in patient satisfaction score, pain score, and wrist supination in comparison to plaster augmentation of K-wiring

Introduction: Dorsally angulated metaphyseal fractures of the proximal phalanges usually occur in the middle aged or elderly and are common. Reduction is difficult to maintain with non-operative treatment, due the action of the intrinsic muscles. Most techniques advocated in the literature suggest a transmetacarpal K-wire fixation. We present the results of a simple method of stabilisation using intramedullary K-wires without violating the articular surface. Methods: Over a three-year period, sixty patients with these fractures were treated in this way. A single wire is inserted through the rim of the proximal phalangeal base with MCPJ fully flexed, avoiding transfixion of the collateral ligament. The wire is passed up the medullary canal, across the fracture and up either to subchondral bone or to engage the opposite cortex. The metacar-pophalangeal joints were immobilised with a thermoplastic splint in full flexion and interphalangeal joints mobilised under supervision by the hand therapists. The wire was removed at three weeks. Results: Most patients achieved a full range of movement at 6 weeks follow-up. There were no pin site infections. Conclusion: Dorsally angulated metaphyseal fractures of the proximal phalanges fractures are difficult to treat by non-operative means. If the fracture heals in an angulated position the altered line of pull of the intrinsics will result in loss of flexion at the MCPJ and of power grip. This method is straightforward and gives satisfactory results. It avoids damage to the articular surface of the MCPJ, allows mobilisation of the entire digit and reliably controls the fracture

Purpose of study: Aim was to evaluate the functional outcome of External fixation supplemented by K-wire fixation in communited fractures of lower end radius and compare the outcome in closed and open fractures treated by this method. Methods: External fixation along with K-wire fixation was done in 25 consecutive patients (mean age-41.9 years; range-20 to 72 years). According to Frykman’s classification, there were 3 Type VII fractures and 22 Type VIII fractures. 15 fractures were closed type, 4 were Open grade I, 4 were Open grade II and 2 were Open grade III according to Gustilo and Anderson classification. The mean follow-up period was 14.1 months (range- 6 to 25 months). Results: The mean union time was 7 weeks (range-5 to 8 weeks). Mean dorsiflexion was 37.6 degrees, mean palmar flexion was 44.4 degrees, mean ulnar deviation was 16.2 degrees, mean radial deviation was 14.2 degrees, mean supination was 73 degrees and mean pronation was 79 degrees. Comparison of union time, dorsiflexion, palmarflexion, ulnar deviation, radial deviation, supination and pronation between closed, Open grade I, Open grade II and Open grade III fractures revealed no significant difference. Significant radial shortening was observed in patients with open fractures (P=0.004). 1 patient developed schanz pin tract infection and late distal radioulnar joint subluxation was seen in 4 patients. Conclusion: Supplementation of External fixator with K-wires is an effective method for treating both closed and open fractures of distal end radius however; radial shortening is seen in some cases with open fractures

Purpose Of Study: To evaluate the results and functional outcome of use of three lateral K wires in supracondylar fracture fixation in children.

Methods And Results: It is a prospective study of 25 cases of supracondylar fractures over a period of three years from 2001, in children between 2 to 9 years, comprising of closed manipulation and percutaneous fixation with 3 lateral K wires, all done by the same surgeon.

Patients were immobilised for 3 weeks and K wires removed at that time. They were followed up till they regained full range of movements in the elbow.

Of the 25 cases, 2 were previously fixed with crossed K wires and were revised because of displacement . One patient had a delayed fixation because of gross swelling and was initially managed with traction.

Pin tract infection was noted in one case and responded to antibiotic therapy.

All the patients regained full range of movements and no angulatory deformity or loss of fixation was noted at the end of follow up.

Conclusion: Fixation with three lateral K wires is an excellent technique in treating displaced supracondylar fractures in children.

Aims: To compare the cost of intra-medullary implants used stabilising paediatric diaphyseal fractures with the clinical outcome. Methods: Between March 1994 and August 2001, at two centres, The Womenñs and Childrenñs Hospital, Adelaide, Australia and The Royal London Hospital, London UK 60 children were surgically treated for diaphyseal forearm fractures using Elastic Stable Intramedullary Nails (ESIN) or 2.5mm Kirschner wires. Having established no difference in the clinical outcome or subjective disability of either technique we compared the implant cost directly. Results: The two treatments both resulted in an excellent outcome with all fractures leading to union with no subjective disability. The Kirscner wires cost £3.00 per wire while the ESI Nails cost between £57.50 and £ 113.30 per wire, depending on the dimensions. Conclusions: We were not able to demonstrate any difference in outcome between ESIN and K-Wiring, although the nails do offer theoretical advantages. The cost implications of using the special implant are twenty fold or more, and as the pressures of cost cutting grow, we wonder if theoretical advantage is Òvalue for moneyÒ.

Certain technical advances, such as flexible intramedullary fixation and bioreabsorbable implants, have further increased enthusiasm for surgical management of pediatric fractures.» (Flynn et al.). In the Paediatric Surgery Department biodegradable pins of solid polydioxanone (PDS) in management of paediatric fractures have been used since April 1986. PDS pins are too soft for the osteosynthesis in fractures with fragments under high tensile pressures. However, we have successfully carried out a large number of internal fixations in children’s elbows. This is based on accurate distribution of PDS pins and careful positioning of periostal sutures and the adjacent disrupted muscles. Our technique, as presented at the 2nd European Congress of Paediatric Surgery in Madrid in 1997, is to fix temporarily the repositioned fractured fragment with Kirschner’s metal wire. Following osteosynthesis with PDS, the protruding K-wire is left in place for seven days until the limb is safely immobilized.

A total of 96 patients were operated. The purpose of the study is to compare osteosynthesis with PDS pins (Group A) with that of metallic K-wire (Group B). Each group consisted of 48 children. General characteristics (age, sex, and fracture types) were statistically the same (P > 0.05). In Group A, with children between 2 and 13 years, or 9.3 on average, 21 children were with the lateral condyle fractures (43.75%), 25 children with medial epicondyle fractures (52.08%), and 2 children with medial condyle fractures (4.16%). In Group B, with children between 2 and 14 years, or 8.7 on average, 26 children were with lateral condyle fractures (54.16%), 19 children with medial epicondyle fractures (39.58%), and 3 with medial condyle fractures (6.25%). The study excludes Milch Type II fractures of medial and lateral condyles. The results have been examined in the follow-up period of one, three, and six months of two different methods according to Flynn’s criteria. After statistical evaluation the differences obtained had no statistical significance (P > 0.05). However, satisfaction score (0 – 10) is significantly higher in Group A than in Group B for both parents and evaluators (P < 0.05). Both treatments exhibit good results with the exception that the use of metal osteosynthetic material requires another operation. If metal wires are used and cut just underneath the skin, protruding with local inflammation may appear. Proper use of PDS pins requires no further operation. This is to the benefit for both the patient and rehabilitation staff.

Olecranon fractures are common injuries representing roughly 5% of pediatric elbow fractures. The traditional surgical management is open reduction and internal fixation with a tension band technique where the pins are buried under the skin and tamped into the triceps. We have used a modification of this technique, where the pins have been left out of the skin to be removed in clinic. The purpose of the current study is to compare the outcomes of surgically treated olecranon fractures using a tension-band technique with buried k-wires (PINS IN) versus percutaneous k-wires (PINS OUT). We performed a retrospective chart review on all pediatric patients (18 years of age or less) with olecranon fractures that were surgically treated at a pediatric academic center between 2015 to present. Fractures were identified using ICD-10 codes and manually identified for those with an isolated olecranon fracture. Patients were excluded if they had polytrauma, metabolic bone disease, were treated non-op or if a non-tension band technique was used (ex: plate/screws). Patients were then divided into 2 groups, olecranon fractures using a tension-band technique with buried k-wires (PINS IN) and with percutaneous k-wires (PINS OUT). In the PINS OUT group, the k-wires were removed in clinic at the surgeon's discretion once adequate fracture healing was identified. The 2 groups were then compared for demographics, time to mobilization, fracture healing, complications and return to OR. A total of 35 patients met inclusion criteria. There were 28 patients in the PINS IN group with an average age of 12.8 years, of which 82% male and 43% fractured their right olecranon. There were 7 patients in the PINS OUT group with an average age of 12.6 years, of which 57% were male and 43% fractured their right olecranon. All patients in both groups were treated with open reduction internal fixation with a tension band-technique. In the PINS IN group, 64% were treated with 2.0 k-wires and various materials for the tension band (82% suture, 18% cerclage wire). In the PINS OUT group, 71% were treated with 2.0 k-wires and all were treated with sutures for the tension band. The PINS IN group were faster to mobilize (3.4 weeks (range 2-5 weeks) vs 5 weeks (range 4-7 weeks) p=0.01) but had a significantly higher complications rate compared to the PINS OUT group (6 vs 0, p =0.0001) and a significantly higher return to OR (71% vs 0%, p=0.0001), mainly for hardware irritation or limited range of motion. All fractures healed in both groups within 7 weeks. Pediatric olecranon fractures treated with a suture tension-band technique and k-wires left percutaneously is a safe and alternative technique compared to the traditional buried k-wires technique. The PINS OUT technique, although needing longer immobilization, could lead to less complications and decreased return to the OR due to irritation and limited ROM

Our aim was to explore factors associated with early post operative infection for surgically managed base of 4th/5th metacarpal fractures. We hypothesised that K-wires crossing the 4th and 5th carpometacarpal joint (CMCJ) would be associated with an increased risk of post-operative infection. Data from consecutive patients requiring surgical fixation for a base of 4th/5th metacarpal fracture from October 2016 to May 2021 were collected. Patient demographics, time to surgery, length of surgery, operator experience, use of tourniquet, intra-operative antibiotics, number and thickness of K-wire used, as well as whether or not the K-wires crossed CMCJ joints were recorded. Factors associated with post operative infection were assessed using Chi Squared test and univariable logistic regression using R studio. Of 107 patients, 10 (9.3%) suffered post operative infection. Time to surgery (p 0.006) and length of operation (p=0.005) were higher in those experiencing infection. There was a trend towards higher risk of infection seen in those who had K-wires crossed (p=0.06). On univariable analysis, patients who had wires crossed were >7 times more likely to experience infection than those who didn't (OR 7.79 (95% CI, 1.39 - 146.0, p=0.056). Age, smoking, K-wire size, number of K-wires used, intraoperative antibiotics, tourniquet use and operator experience were not associated with infection. In patients with a base of 4th/5th metacarpal fractures requiring surgical fixation, we find an increased risk of post-operative infection associated with K-wires crossing the CMCJ, which has implications for surgical technique. Larger prospective studies would be useful in further delineating these findings

Our aim was to ascertain if K-wire configuration had any influence on the infection and complication rate for base of 4th and 5th metacarpal fractures. We hypothesised that in individuals whose wires crossed the 4th and 5th carpometacarpal joint (CMCJ), the rate of complications and infection would be higher. Data was retrospectively analysed from a single centre. 106 consecutive patients with a base of 5th (with or without an associated 4th metacarpal fracture) were analysed between October 2016 and May 2021. Patients were split into two groups for comparison; those who did not have K-wires crossing the CMCJ's and those in whose fixation had wires crossing the joints. Confounding factors were accounted for and Statistical analysis was performed using SPSS version 20 software. Of 106 patients, 60 (56.6%) patients did have K-wires crossing the CMCJ. Wire size ranged from 1.2-2.0 with 65 individuals (65.7%) having size 1.6 wires inserted. The majority of patients, 66 (62.9%) underwent fixation with two wires (range 1-4). The majority of infected cases (88.9%) were in patients who had k-wires crossing the CMCJ, this trended towards clinical significance (p=0.09). Infection was associated with delay to theatre (p=0.002) and longer operative time (p=0.002). In patients with a base of 4th and 5th metacarpal fractures, we have demonstrated an increased risk of post-operative infection with a K-wire configuration that crosses the CMCJ. Biomechanical studies would be of use in determining the exact amount of movement across the CMCJ, with the different K-wire configuration in common use, and this will be part of a follow-up study

Thermal osteonecrosis is a side effect when used Kirschner (K) wires and drills in orthopaedic surgeries. This osteonecrosis may endanger the fixation. Orthopaedic surgeons sometimes have to use unsharpened K-wires in emergent surgery. The thermal effect of used and unsharpened K wire is ambiguous to the bone. This experimental study aims to assess the thermal osteonecrosis while drilling bone with three different types of K-wires especially a previously used unsharpened wire and its thermographic measurements correlation. Two different speeds of rotation were chosen to investigate the effect of speed on thermal necrosis to the bone. A total of 16 New Zealand white rabbits weighing a mean of 2.90 kg (2.70 – 3.30 kg) were used. All rabbits were operated under general anaesthesia in a sterile operating room. Firstly, 4 cm longitudinal lateral approach was used to the right femur and then the femur was drilled with 1.0 mm trochar tip, spade tip and previously used unsharpened K-wires and 1.0 mm drill bit at 1450 rpm speed. Left femur was drilled with same three type K-wires and drill bit at 330 rpm speed. One cm distance was left among four penetrations on the femur. The thermal changes were recorded by Flir® E6 Thermal Camera from 50 cm distance and 30-degree angle. Thermographic measurements saved for every drilling process and recorded for the highest temperature (°C) during the drilling. All subjects were sacrificed post-operatively on the eighth day and specimens were prepared for the histological examination. The results of osteonecrosis assessment score and thermographic correlation were evaluated statistically. Histological specimens were evaluated by the scoring of osteonecrosis, osteoblastic activity, haemorrhage, microfracture and inflammation. Results were graded semi-quantitatively as none, moderate or severe for osteonecrosis, haemorrhage and inflammation. The microfracture and osteoblastic activity were evaluated as present or absent. There was no meaningful correlation between osteonecrosis and the drilling speed (p=0.108). There was less microfracture zone which was drilled with trochar tip K-wires at 1450 rpm speed (p=0.017). And the drilling temperature of trochar tip K-wires was higher than the others(p=0.001). Despite this evaluation, osteonecrosis zone of spade and unsharpened tip K-wires were more than trochar tip K-wires (p=0.039). The drill bit at 330 rpm caused the least osteonecrosis and haemorrhage and respectfully the lowest drilling temperature (p=0,001). The osteoblastic activity shows no difference between the groups. (p=0,122; 0,636;0.289). On the contrary to the literature, our experiment showed that there is no meaningful correlation between osteonecrosis score and temperature produced by drilling. The histological assessment showed the osteonecrosis during short drilling time but, not clarify the relation with drilling temperature. Eventually, the osteonecrosis showed a positive correlation with drilling time independently of drilling temperature at 330 rpm. (p=0,042) These results show that we need more studies to understand about osteonecrosis and its relationship with drilling heat temperature. Trochar tip K-wires creates higher drilling temperature but less osteonecrosis than a spade and unsharpened cut tip K-wires. Using unsharpened tip K-wire causes more osteonecrosis. Previously used and, unsharpened K-wires should be discarded

Aims. Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the Staphylococcus aureus phage 191219 and gentamicin against haematogenous and early-stage biofilm implant-related infections in Galleria mellonella. Methods. For the haematogenous infection, G. mellonella larvae were implanted with a Kirschner wire (K-wire), infected with S. aureus, and subsequently phages and/or gentamicin were administered. For the early-stage biofilm implant infection, the K-wires were pre-incubated with S. aureus suspension before implantation. After 24 hours, the larvae received phages and/or gentamicin. In both models, the larvae also received daily doses of phages and/or gentamicin for up to five days. The effect was determined by survival analysis for five days and quantitative culture of bacteria after two days of repetitive doses. Results. In the haematogenous infection, a single combined dose of phages and gentamicin, and repetitive injections with gentamicin or in combination with phages, resulted in significantly improved survival rates. In the early-stage biofilm infection, only repetitive combined administration of phages and gentamicin led to a significantly increased survival. Additionally, a significant reduction in number of bacteria was observed in the larvae after receiving repetitive doses of phages and/or gentamicin in both infection models. Conclusion. Based on our results, a single dose of the combination of phages and gentamicin is sufficient to prevent a haematogenous S. aureus implant-related infection, whereas gentamicin needs to be administered daily for the same effect. To treat early-stage S. aureus implant-related infection, repetitive doses of the combination of phages and gentamicin are required. Cite this article: Bone Joint Res 2024;13(8):383–391

Introduction. Derotation osteotomies are commonly performed in paediatric orthopaedic and limb reconstruction practice. The purpose of this study was to determine whether the use of a digital inclinometer significantly improves the accuracy in attaining the desired correction. Materials & Methods. We designed an electronic survey regarding derotation femoral osteotomy (DFO) including methods of intra-operative angular correction assessment and acceptable margins of error for correction. This was distributed to 28 paediatric orthopaedic surgeons in our region. A DFO model was created, using an anatomic sawbone with foam covering. 8 orthopaedic surgeons each performed two 30-degree DFOs, one using K-wires and visual estimation (VE), and the other using a Digital Inclinometer (DI). Two radiologists reported pre and post procedure rotational profile CT scans to assess the achieved rotational correction. Results. There was a 68% response rate to the survey. The most popular methods of estimating intra-operative correction were reported to be K-wires and rotation marks on bone. The majority of respondents reported that a 6–10 degree margin of error was acceptable for a 30-degree derotation. This was therefore set as the upper limit for acceptable error margin in the simulation study. The mean error in rotation in the VE group of simulated DFO was 19.7 degrees, with error>5 degrees and error>10 degrees in 7 (88%) and 6 (75%) cases respectively. Mean error in DI group was 3.1 degrees, with error>5 degrees in 1 case (13%). Conclusions. Our results show that the compared to conventional techniques, the use of an inclinometer significantly improves the accuracy of femoral de-rotation and significantly reduces the incidence of unacceptable errors in correction. We would suggest that digital inclinometers be used to assess intra-operative correction during derotation osteotomies

Aim. In trauma surgery, the development of biomaterial-associated infections (BAI) is one of the most common complications affecting trauma patients, requiring prolonged hospitalization and the intensive use of antibiotics. Following the attachment of bacteria on the surface of the biomaterial, the biofilm-forming bacteria could initiate a chronic implant-related infection. Despite the use of conventional local and systemic antibiotic therapies, persistent biofilms involve various resistance mechanisms that contribute to therapeutic failures. The development of in vivo chronic BAI models to optimize antibiofilm treatments is a major challenge. Indeed, the biofilm pathogenicity and the host response need to be finely regulated, and compatible with the animal lifestyle. Previously, a Galleria mellonella larvae model for the formation of an early-stage biofilm on the surface of a Kirschner (K)-wire was established. In the present study, two models of mature biofilm using clinical Staphylococcus aureus strains were assessed: one related to contaminated K-wires (in vitro biofilm maturation) and the second to hematogenous infections (in vivo biofilm maturation). Rifampicin was used as a standard drug for antibiofilm treatment. Method. In the first model, biofilms were formed following an incubation period (up to 7 days) in the CDC Biofilm Reactor (CBR, BioSurface Technologies). Then, after implantation of the pre-incubated K-wire in the larvae, rifampicin (80 mg/kg) was injected and the survival of the larvae was monitored. In the second model, biofilm formation was achieved after an incubation period (up to 7 days) inside the larvae and then, after removing the K-wires from the host, in vitro rifampicin susceptibility assays were performed (according to EUCAST). Results. The first model indicate that in vitro biofilm maturation affects the bacterial pathogenicity in the host, depending on the S. aureus strain used. Furthermore, the more the biofilm is matured, the more the rifampicin treatment efficiency is compromised. The second model shows that, despite the fast in vivo biofilm formation in the host, the number of bacteria, either attached to the surface of the K-wire surface or in surrounding tissue of the larvae, was not increased over time. Conclusions. Altogether, these results allow the establishment of biofilm models using G. mellonella larvae in order to understand the impact of biofilm maturation on both the bacterial pathogenicity and the efficiency of antibiofilm treatments