Introduction Debonding at the cement-prosthesis interface leading to stem movement and abrasion, has been proposed as initiating events in aseptic loosening of cemented total hip arthroplasties. A polished tapered or an absolutely stable stem possibly minimises this risk. This study evaluated a cemented, precoated femoral stem for stable fixation. Methods The study included 24 patients, mean age of 64 years (48 to 78) undergoing single total hip arthroplasty for osteoarthritis. All were treated with cemented Definition (Stryker) stems which are straight, chromium-cobalt, with an integrated proximal polymethylmethacrylate mantle. One surgeon using fourth generation cementation techniques performed all surgeries. UHMWPE cups and Zirconia heads were used. At the time of surgery, tantalum markers were inserted into the femur, cement and stem for Radiostereometric analysis (RSA) of migration. Measurements were performed at two, 12 and 24 months intervals. Standard radiographs and Harris Hip Scores were obtained post-operatively and at two years. Results During the first two years post-operatively the stems were shown to be absolutely fixed within the cement mantle and the mantle itself stable with the femur. At two years the mean subsidence of the stem in relation to the femur was 0.00 mm (SD 0.1), while the cement mantle subsided 0.2 mm (SD 0.2) in relation to the femur. The femoral head mean rotation was 0.02 retroversion. Postoperative radiolucent lines of > 1 mm where present in a mean of 1.4% (0 to 5%) of the cement-bone interfaces. This remained unchanged at two years (0 to 3%). Stems were in average positioned 0.8 in varus (1.2 valgus to 4.0 varus). Harris Hip Scores improved from a mean of 46 (23 to 68) pre-operatively to 93 (57 to 100) at two years. Conclusions This is the first stem where no migration could be detected during the first two years. These results so far indicate good long-term performance of this precoated stem

Clinical Problen: the avulsion fracture of the MT V bone and the Jones fractures are typical fractures under tenssion and therefore often require osteosynthesis. Materials and Methods: to avoid soft tissue problems due to the open reduction and implant on the bone surface on the lateral foot a percutaneus technique with a 3,5mm XXS locked compression nail was developed. The fracture is reduced with the gide wire witch is also used for the canulated 3,5mm drill wich prepares the canal for the nail. The locking is performed on both sides of the fracture with one 2mm threated wire and the dynamic compression of the Fracture of the fracture is performed with a set screw in the nail. All patients are allowed to walk free with normal foot wear. From Jul 1999 to Jan.2006 77 patients were treated according to the above technique. Results: Tha OAFAS of the patients preoperativ was 22 and postoperative 96. No pseudarthrosis or implant failures occured but in 53 patients (69%) implant removal was necessary because patients had discomfort due to the implant. Conclusion: the XXS nail is a new method for minimal invasive and stable fixation of MTV fractures with full weight bearing capacity in low complication rate. However in most cases implant removal is indicated

The avulsion fracture of the V-th metatarsal and Jones fractures often show delayed and non-union. The tension belt osteosynthesis shows often soft tissue problems due to the thin soft tisshe covering. A new minimal invasive method with the 3,5mm XXS nail and the clinical results are presented. Percutaneously the fracture is reduced with a K-wire as a joy stick. This or if the direction needed is different a second K-wire as guide is introduced and with a canulated 3,5 mm drill the place for the nail is prepared. Proximal and distal to the fracture one threaded wire locking and fracture compression through the nail (proximal longitudinal holes) are performed. 77 patients with a XXS nail fixation of MT V fractures were treated from July 1999 to Jan.2006. Clinical and radiological re-examination at 1 to 6 years were performed. The AOFAS was 22 pre- and 96 postoperatively. No pseudarthrosis but in 53 patients implant removal was done in part due to local discomfort. This was strictly correlated to the length of the threaded wires to the bone surface. 95% reached pretrauma activity levels. Satisfaction was 9 from 10 points. The XXS nails allow a percutaneous stable fixation of the avulsion and Jones fractures of the V-th metatarsus. The complication rate is low

The avulsion fracture of the V-th metatarsal and Jones fractures often show delayed and non-union. The tension belt osteosynthesis shows often soft tissue problems due to the thin soft tisshe covering. A new minimal invasive method with the 3,5mm XXS nail and the clinical results are presented. Percutaneously the fracture is reduced with a K-wire as a joy stick. This or if the direction needed is different a second K-wire as guide is introduced and with a canulated 3,5 mm drill the place for the nail is prepared. Proximal and distal to the fracture one threaded wire locking and fracture compression through the nail (proximal longitudinal holes) are performed. 77 patients with a XXS nail fixation of MT V fractures were treated from July 1999 to Jan.2006. Clinical and radiological re-examination at 1 to 6 years were performed. The AOFAS was 22 pre- and 96 postoperatively. No pseudarthrosis but in 53 patients implant removal was done in part due to local discomfort. This was strictly correlated to the length of the threaded wires to the bone surface. 95% reached pretrauma activity levels. Satisfaction was 9 from 10 points. The XXS nails allows a percutaneous stable fixation of the avulsion and Jones fractures of the V-th metatarsus. The complication rate is low

There is a growing trend towards using pre-clinical models of atrophic non-union. This study investigated different fixation devices, by comparing the mechanical stability at the fracture site of tibia bone fixed by either intramedullary nail, compression plate or external fixator. 40 tibias from adult male Wistar rats' cadavers were osteotomised at the mid-shaft and a gap of 1 mm was created and maintained at the fracture site to simulate criteria of atrophic non-union model. These were divided into five groups (n=8 in each): the first group was fixed with 20G intramedullary nail, the second group with 18G nail, the third group with 4-hole plate, the fourth group with 6-hole plate, and the fifth group with external fixator. Tibia was harvested by leg disarticulation from the knee and ankle joints, the soft tissues were carefully removed from the leg, and tibias were kept hydrated throughout the experiment. Each group was then subdivided into two subgroups for mechanical testing: one for axial loading (n=4) and one for 4-point bending (n=4). Statistical analysis was carried out by ANOVA with a fisher post-hoc comparison between groups. A p-value less than 0.05 was considered statistically significant. Axial load to failure data and stiffness data revealed that intramedullary nails are significantly stronger and stiffer than other devices, however there was no statistically significant difference axially between the nail thicknesses. In bending, load to failure revealed that 18G nails are significantly stronger than 20G. We concluded that 18G nail is superior to the other fixation devices, therefore it has been used for in-vivo experiments to create a novel model of atrophic non-union with stable fixation

Aims. In this study, we aimed to explore surgical variations in the Femoral Neck System (FNS) used for stable fixation of Pauwels type III femoral neck fractures. Methods. Finite element models were established with surgical variations in the distance between the implant tip and subchondral bone, the gap between the plate and lateral femoral cortex, and inferior implant positioning. The models were subjected to physiological load. Results. Under a load of single-leg stance, Pauwels type III femoral neck fractures fixed with 10 mm shorter bolts revealed a 7% increase of the interfragmentary gap. The interfragmentary sliding, compressive, and shear stress remained similar to models with bolt tips positioned close to the subchondral bone. Inferior positioning of FNS provided a similar interfragmentary distance, but with 6% increase of the interfragmentary sliding distance compared to central positioning of bolts. Inferior positioning resulted in a one-third increase in interfragmentary compressive and shear stress. A 5 mm gap placed between the diaphysis and plate provided stability comparable to standard fixation, with a 7% decrease of interfragmentary gap and sliding distance, but similar compressive and shear stress. Conclusion. Finite element analysis with FNS on Pauwels type III femoral neck fractures revealed that placement of the bolt tip close to subchondral bone provides increased stability. Inferior positioning of FNS bolt increased interfragmentary sliding distance, compressive, and shear stress. The comparable stability of the fixation model with the standard model suggests that a 5 mm gap placed between the plate and diaphysis could viably adjust the depth of the bolt. Cite this article: Bone Joint Res 2022;11(2):102–111

Aims. One of the main causes of tibial revision surgery for total knee arthroplasty is aseptic loosening. Therefore, stable fixation between the tibial component and the cement, and between the tibial component and the bone, is essential. A factor that could influence the implant stability is the implant design, with its different variations. In an existing implant system, the tibial component was modified by adding cement pockets. The aim of this experimental in vitro study was to investigate whether additional cement pockets on the underside of the tibial component could improve implant stability. The relative motion between implant and bone, the maximum pull-out force, the tibial cement mantle, and a possible path from the bone marrow to the metal-cement interface were determined. Methods. A tibial component with (group S: Attune S+) and without (group A: Attune) additional cement pockets was implanted in 15 fresh-frozen human leg pairs. The relative motion was determined under dynamic loading (extension-flexion 20° to 50°, load-level 1,200 to 2,100 N) with subsequent determination of the maximum pull-out force. In addition, the cement mantle was analyzed radiologically for possible defects, the tibia base cement adhesion, and preoperative bone mineral density (BMD). Results. The BMD showed no statistically significant difference between both groups. Group A showed for all load levels significantly higher maximum relative motion compared to group S for 20° and 50° flexion. Group S improved the maximum failure load significantly compared to group A without additional cement pockets. Group S showed a significantly increased cement adhesion compared to group A. The cement penetration and cement mantle defect analysis showed no significant differences between both groups. Conclusion. From a biomechanical point of view, the additional cement pockets of the component have improved the fixation performance of the implant. Cite this article: Bone Joint Res 2022;11(4):229–238

Aim: A debonding in the stem-cement interface is often the þrst event leading to clinical failure of hip prostheses. We have tested the stability of a pre cement mantled stem were the concept of composite beam stems is taken to a new level. Methods: Twenty four patients with a mean age of 64 years (48–73), a weight of 72 kg and allocated to total hip arthroplasty due to OA were operated. All received a Deþnition stem (a straight CoCr stem proximally coated with a PMMA mantle). All poly cups, Palacos cement and 4th generation cementing technique was used in all. Tantalum markers were inserted in femur and the stem and migration measured with RSA at 2, 12 and 24 months. Radiographs and Harris hip score was obtained post op and at 2 years. Results: The subsidence of stems in relation to femur was 0.00 mm (SEM 0.02) and the cement mantle subsided 0.2 mm (SEM 0.02) in relation to femur. The femoral head rotated backward 0.02 mm.(SEM 0.07) Post op radiolucent lines of 1 mm thickness or more were present to a mean of 0.3% (0–3%) in the cement-bone interface at 2 years. Harris hip score increased from a mean of 46 (23–68) pre op to 93 (57–100) at 2 years. Conclusion: Deþnition is the þrst stem investigated with RSA were no migration at all could be recorded the þrst 2 years. Togeher with a stable cement mantle and no radiolucent lines it so far indicates a good long term performance of the Deþnition stem.

The Fixion expandable nailing system provides an intramedullary fracture fixation solution without the need for locking screws. Proponents of this system have demonstrated shorter surgery times with rapid fracture healing, but several centres have reported suboptimal results with loss of fixation. This is the largest comparative series to be reported to date.

We compared outcomes between 50 consecutive diaphyseal tibial fractures treated with a Fixion device at our institution to an age, sex and fracture configuration matched series of 57 fractures at a neighbouring hospital treated with a conventional interlocked intramedullary nail. Minimum follow up time was 2 years.

Operating time was significantly reduced in the Fixion group (mean 61 minutes, range 20–99) compared to the interlocked group (88 minutes, 52–93), p< 0.00001. The union rate was no different between the Fixion group (93.9%) and the interlocked group (96.5%), p=0.527. Time to clinical and radiological union was significantly faster in the Fixion group (median 85 days, range 42–243) compared to the interlocked group (119, 70–362), p< 0.0001. The overall reoperation rate was lower in the Fixion series (24.5% vs 38.6%, p=0.121), although the majority of reoperations in the interlocked group were more minor, for screw removal. 3 Fixion nails were revised for fixation failure and 2 manipulations were required for rotational deformities after falls; all of these patients were non-compliant with post-operative instructions. There were no fixation failures in the interlocked group. 3 fractures were noted to propagate during inflation of Fixion nails.

The Fixion nail is faster to implant and allows more physiological loading of the fracture, with a faster union time. However, these advantages are offset by a reduction in construct stability. Our results have demonstrated a learning curve with a reduction in complications as our indications were narrowed, avoiding osteoporotic, multifragmentary, unstable fractures and non-compliant patients

Displaced fractures of the radial neck in children can lead to limitation of elbow and forearm movements if left untreated. Several management techniques are available for the treatment of radial neck fractures in children. Open reduction can disturb the blood supply of the soft tissue surrounding the radial head epiphysis and is associated with more complications.

We report our experience of treating 14 children between the age of 4 and 13 years, who had severely displaced radial neck fractures (Judet type 111 and 1V). 12 patients were treated with indirect reduction and fixation using the Elastic Stable Intramedullary Nail (ESIN) technique, (3 with assisted percutaneous K-wire reduction) and 2 had open reduction followed by ESIN fixation of the radial head fragment. This method reduces the need for open reduction and thus the complication rate. Three patients had associated fractures of the same forearm which was also treated surgically at the same time. We routinely immobilised the forearm for two weeks and removed the nail in all cases in an average of 12 weeks. We had no complication with implant removal.

All 14 patients have been followed up for average of 28 months. One patient (7%) developed asymptomatic avascular necrosis (AVN) of the head of radius. Thirteen patients (93%) had excellent result on final review. One patient had neuropraxia of the posterior interosseous nerve which recovered within 6 weeks.

In conclusion we advocate ESIN for the closed reduction and fixation of severely displaced radial neck fractures in children. It remains a useful fixation method even if open reduction is required and allows early mobilisation.

Introduction: Regarding operative treatment of proximal humeral fractures no current treatment guidelines have been established so far. Angular stable implant for stabilisation of proximal humerus fractures find increased spreading. Aim of the study was the evaluation of pain, function subjective contentment and especial the surgical complications after stabilization with the Proximal Humerus Plate.

Methods: 214 patients were treated with PHP from 8/2001 to 2/2005 and documented prospectively. The humeral head fragment was fixated with four angular stable self locking screws. Neer–Classification showed 102 2-part, 71 3-part and 41 4-part fractures. Follow up (x-ray, VAS, Constant Score) was performed after 6 and 12 months respectively.

Results: Until now 154 (72%) Patients were available for follow up. Complications were seen in 31 cases (20%). Leading were perforation of self locking screws of the humeral head (10), followed by secondary dislocation (7, 3 of them with re-trauma), secondary humeral head necrosis (6), implant failure (3), malposition (varus) (3), and infection (2). In 18 cases (12%) re-operation was necessary: removal of screws (7), re-osteosynthesis (6), hemiarthroplasty (5). The constant score (compared to uninjured side) was 6 months postoperatively 61 (71%) and after 12 months 73 (82%).

Conclusion: The problems of osteosynthesis of proximal humeral fractures using an internal fixator are shown by the complications. Especially rigid self locking head screws show a high risk to perforate the humeral articular surface. On the other hand results showed good primary and secondary stability in comparison with the literature.

Complex acetabular reconstruction for oncology and bone loss are challenging for surgeons due to their often hostile biological and mechanical environments. Titrating concentrations of silver ions on implants and alternative modes of delivery allow surgeons to exploit anti-infective properties without compromising bone on growth and thus providing a long-term stable fixation. We present a case series of 12 custom acetabular tri-flange and custom hemipelvis reconstructions (Ossis, Christchurch, New Zealand), with an ultrathin plasma coating of silver particles embedded between layers of siloxane (BioGate HyProtect™, Nuremberg, Germany). At the time of reporting no implant has been revised and no patient has required a hospital admission or debridement for a deep surgical site infection. Routine follow up x-rays were reviewed and found 2 cases with loosening, both at their respective anterior fixation. Radiographs of both cases show remodelling at the ilium indicative of stable fixation posteriorly. Both patients remain asymptomatic. 3 patients were readmitted for dislocations, 1 of whom had 5 dislocations within 3 weeks post-operatively and was immobilised in an abduction brace to address a lack of muscle tone and has not had a revision of their components. Utilising navigation with meticulous implant design and construction; augmented with an ultrathin plasma coating of silver particles embedded between layers of siloxane with controlled and long-term generation of silver ion diffusion has led to outstanding outcomes in this series of 12 custom acetabular and hemipelvis reconstructions. No patients were revised for infection and no patients show signs of failure of bone on growth and incorporation. Hip instability remains a problem in these challenging mechanical environments and we continue to reassess our approach to this multifaceted problem

Introduction. The management of fracture-related infection has undergone radical progress following the development of international guidelines. However, there is limited consideration to the realities of healthcare in low-resource environments due to a lack of available evidence in the literature from these settings. Initial antimicrobial suppression to support fracture union is frequently used in low- and middle-income countries despite the lack of published clinical evidence to support its practice. This study aimed to evaluate the outcomes following initial antimicrobial suppression to support fracture union in the management of fracture-related infection. Materials & Methods. A retrospective review of consecutive patients treated with initial antimicrobial suppression to support fracture healing followed by definitive eradication surgery to manage fracture-related infections following intramedullary fixation was performed. Indications for this approach were; a soft tissue envelope not requiring reconstructive surgery, radiographic evidence of stable fixation with adequate alignment, and progression towards fracture union. Results. This approach was associated with successful treatment in 51/55 (93%) patients. Fracture union was achieved in 52/55 (95%) patients with antimicrobial suppression alone. Remission of infection was achieved in 54/55 (98%) patients following definitive infection eradication surgery. Following antibiotic suppression, 6/46 (13%) pathogens isolated from intra-operative samples demonstrated multi-drug resistance. Conclusions. Initial antimicrobial suppression to support fracture healing followed by definitive infection eradication surgery was associated with successful treatment in 93% of patients. The likelihood of remission of infection increases when eradication surgery is performed in a healed bone. This approach was not associated with an increased risk of developing multi-drug-resistant infections compared to contemporary bone infection cohorts in the published literature

Introduction. The Oxford Unicompartmental Knee Replacement (OUKA) is the most popular unicompartmental knee replacement (UKR) in the New Zealand Joint Registry with the majority utilising cementless fixation. We report the 10-year radiological outcomes. Methods. This is a prospective observational study. All patients undergoing a cementless OUKA between May 2005 and April 2011 were enrolled. There were no exclusions due to age, gender, body mass index or reduced bone density. All knees underwent fluoroscopic screening achieving true anteroposterior (AP) and lateral images for radiographic assessment. AP assessment for the presence of radiolucent lines and coronal alignment of the tibial and femoral components used Inteliviewer radiographic software. The lateral view was assessed for lucencies as well as sagittal alignment. Results. 687 OUKAs were performed in 641 patients. Mean age at surgery was 66 years (39–90yrs), 382 in males and 194 right sided. 413 radiographs were available for analysis; 92 patients had died, 30 UKRs had been revised and 19 radiographs were too rotated to be analysed the remainder were lost to follow-up. Mean radiograph to surgery interval was 10.2 years (7.1–16.2yrs). RLLs were identified in zone 1 (3 knees), zone 2 (2 knees), zone 3 (3 knees), zone 5 (3 knees), zone 6 (2 knees) and zone 7 (42 knees). No RLL had progressed, and no case had any osteolysis or prosthesis subsidence. Alignment in the coronal plane: mean 2.90° varus (9.30° varus - 4.49° valgus) of the tibial component to the tibial anatomic axis and the femoral component in mean 4.57° varus (17.02° varus - 9.3° valgus). Sagittal plane posterior tibial slope was a mean 6.30° (0.44° -13.60° degrees) and mean femoral component flexion of 8.11° (23.70° flexion – 16.43° extension). Conclusion. The cementless OUKA demonstrates stable fixation with low revision rates at our centre supporting results earlier published by the design centre

Aim. The treatment of fracture-related infections (FRI) focuses on obtaining fracture healing and eradicating infection to prevent osteomyelitis. Treatment guidelines include removal, exchange, or retention of the implants used according to the stability of the fracture and the time from the infection. Infection of a fracture in the process of healing with a stable fixation may be treated with implant retention, debridement, and antibiotics. Nonetheless, the retention of an intramedullary nail is a potential risk factor for failure, and it is recommended to exchange or remove the nail. This surgical approach implies additional life-threatening risks in elderly fragile hip fracture patients. Our study aimed to analyze the results of implant retention for the treatment of infected nails in elderly hip fracture patients. Methods. Our retrospective analysis included patients 65 years of age or older with an acute fracture-related infection treated with implant retention from 2012 to 2020 in 6 Spanish hospitals with a minimum 1-year follow-up. Patients that required open reduction during the initial fracture surgery were excluded. Variables included in our analysis were patient demographics, type of fracture, date of FRI diagnosis, causative microorganism, and outcome. Treatment success was defined as fracture healing with infection eradication without the need for further hospitalization. Results. A total of 48 patients were identified. Eight patients with open reduction were excluded and 11 did not complete a 1-year follow-up. Out of the 29 remaining patients, the mean age was 81.5 years, with a 21:9, female to male ratio. FRI was diagnosed between 10 and 48 days after initial surgery (mean 26 days). Treatment success was achieved in 24 patients (82.7%). Failure was objectivated in polymicrobial infections or infections caused by microorganisms resistant to antibiofilm antibiotics. Seven patients required more than one debridement with a success rate of 57%. Twelve patients had an infection diagnosed after 21 days from the initial surgery and implant retention was successful in all of them. Conclusion. Our results suggest implant retention is a valid therapeutic approach for fracture-related infection in elderly hip fracture patients treated by closed reduction and intramedullary nailing

Aim. Repeat revision surgery of total hip or knee replacement may lead to massive bone loss of the femur. If these defects exceed a critical amount a stable fixation of a proximal or distal femur replacement may not be possible. In these extraordinary cases a total femur replacement (TFR) may be used as an option for limb salvage. In this retrospective study we examined complications, revision free survival (RFS), amputation free survival (AFS) and risk factors for decreased RFS and AFS following a TRF in cases of revision arthroplasty with a special focus on periprosthetic joint infection (PJI). Method. We included all implantations of a TFR in revision surgery from 2006–2018. Patients with a primary implantation of a TFR for oncological indications were not included. Complications were classified using the Henderson Classification. Primary endpoints were revision of the TFR or disarticulation of the hip. The minimum follow up was 24 month. RFS and AFS were analyzed using Kaplan-Meier method, patients´ medical history was analyzed for possible risk factors for decreased RFS and AFS. Results. After applying the inclusion criteria 58 cases of a TFR in revision surgery were included with a median follow-up of 48.5 month. The median age at surgery was 68 years and the median amount of prior surgeries was 3. A soft tissue failure (Henderson Type I) appeared in 16 cases (28%) of which 13 (22%) needed revision surgery. A PJI of the TFR (Henderson Type IV) appeared in 32 cases (55%) resulting in 18 (31%) removals of the TFR and implantation of a total femur spacer. Disarticulation of the hip following a therapy resistant PJI was performed in 17 cases (29%). The overall 2-year RFS was 36% (95% confidence interval(CI) 24–48%). Patients with a Body mass Index (BMI) >30kg/m² had a decreased RFS after 24 month (>30kg/m² 11% (95%CI 0–25%) vs. <30kg/m² 50% (95%CI 34–66%)p<0.01). The overall AFS after 5 years was 68% (95%CI 54–83%). A PJI of the TFR and a BMI >30kg/m² was significantly correlated with a lower 5-year AFS (PJI 46% (95%CI 27–66%) vs no PJI 100%p<0.001) (BMI >30kg/m² 30% (95% KI 3–57%) vs. <30km/m² 85% (95% KI 73–98%)p<0.01). Conclusions. A TFR in revision arthroplasty is a valuable option for limb salvage but complications in need of further revision surgery are common. Patients with a BMI >30kg/m² should be informed regarding the increased risk for revision surgery and loss of extremity before operation

Aims. The aim of this study was to evaluate the survival of a collarless, straight, hydroxyapatite-coated femoral stem in total hip arthroplasty (THA) at a minimum follow-up of 20 years. Methods. We reviewed the results of 165 THAs using the Omnifit HA system in 138 patients, performed between August 1993 and December 1999. The mean age of the patients at the time of surgery was 46 years (20 to 77). Avascular necrosis was the most common indication for THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (20 to 31). At 20 and 25 years, 113 THAs in 91 patients and 63 THAs in 55 patients were available for review, respectively, while others died or were lost to follow-up. Kaplan-Meier analysis was performed to evaluate the survival of the stem. Radiographs were reviewed regularly, and the stability of the stem was evaluated using the Engh classification. Results. A total of seven stems (4.2%) were revised during the study period: one for aseptic loosening, three for periprosthetic fracture, two for infection, and one for recurrent dislocation. At 20 years, survival with revision of the stem for any indication and for aseptic loosening as the endpoint was 96.0% (95% confidence interval (CI) 92.6 to 99.5) and 98.4% (95% CI 96.2 to 100), respectively. At 25 years, the corresponding rates of survival were 94.5% (95% CI 89.9 to 99.3) and 98.1% (95% CI 95.7 to 99.6), respectively. There was radiological evidence of stable bony fixation in 86 stems (76.1%) and evidence of loosening in four (3.5%) at 20 years. All patients with radiological evidence of loosening were asymptomatic. Conclusion. The Omnifit HA femoral stem offered promising long-term survival into the third decade. Cite this article: Bone Joint J 2024;106-B(3 Supple A):110–114

Introduction. Fibrous dysplasia is a pathological condition, where normal medullary bone is replaced by fibrous tissue and small, woven specules of bone. Fibrous dysplasia can occur in epiphysis, metaphysis or diaphysis. Occationally, biopsy is necessary to establish the diagnosis. We present a review of operative treatment using the Ilizarov technique. The management of tibial fibrous dysplasia in children are curettage or subperiosteal resection to extra periosteal wide resection followed by bone transport. Materials and Methods. A total of 18 patients were treated between 2010 – 2020; 12 patients came with pain and 6 with pain and deformity. All patients were treated by Ilizarov technique. Age ranges from 4–14 years. 12 patients by enbloc excision and bone transportation and 6 patients were treated by osteotomy at the true apex of the deformity by introducing the k/wires in the medullary cavity with stable fixation by Ilizarov device. The longest duration for bone transport was 16 weeks (14–20 weeks) for application, after deformity correction was 20 weeks. We have never used any kind of bone grafts. Results. All the 18 patients were treated successfully by Ilizarov compression distraction device. The patients with localized tibial pathology with deformity had the shortest period on the Ilizarov apparatus, 14 weeks. Conclusions. Preservation and bone regeneration by distraction histogenesis constitutes a highly conservative limb saving surgery. Patients with bone defects of <10 cm, a great deal of preserved healthy tissue and good prognosis are good candidates for these methods

Abstract. INTRODUCTION. Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedic implant devices and has a lot of promise for ‘made-to-measure’ implants produced through additive manufacturing [1]. However, a key limitation of PEEK is that it is bioinert and there is a requirement to functionalise its surface to make the material osteoconductive to ensure a more rapid, improved and stable fixation, in vivo. One approach to solving this issue is to modify PEEK with bioactive materials, such as hydroxyapatite (HA). OBJECTIVE. To 3D PEEK/HA composite materials using a Fused Filament Fabrication (FFF) approach to enhance the properties of the PEEK matrix. METHODS. PEEK/HA composites (0–30% w/w HA/PEEK) were 3D printed using a modified Ultimaker 2+ 3D printer. The mechanical, thermal, physical, chemical and in vitro properties of the 3D printed samples were all studied as part of this work. RESULTS. The CT images of both the filament and the 3D printed samples showed that the HA material was evenly dispersed throughout the bulk all the samples. SEM/EDX measurements highlighted that HA was homogenously distributed across the surface. As the HA content of the samples increases, so does the tensile modulus, ranging from 4.2 GPa (PEEK) to 6.1 GPa (30% HA/PEEK) and are significantly higher than datasheet information of injected molded PEEK samples. All materials supported the growth of osteoblast cells on their surface. CONCLUSIONS. The results clearly show that we can successfully and easily 3D print HA/PEEK composite materials up to 30% w/w HA/PEEK. The samples produced have a homogeneous distribution of HA in both the bulk and surface of all the samples, and their mechanical performance of the PEEK is enhanced by the addition of HA

Aim. External fixator knee arthrodesis is a salvage procedure mainly used in cases of end-stage infected total knee replacement (iTKR). A stable fixation combined with bone-ends compression is basic to achieve knee fusion in such a scenario but providing enough stability can be challenging in the presence of severe bone loss after multiple previous procedures. Compared with monoplanar configuration, a biplanar frame achieves improved coronal stiffness, while providing the advantages of good access to the wound and allowance of early ambulation. Our primary hypothesis stated that a biplanar frame would achieve higher and quicker fusion rate than a monolateral configuration. Method. We conducted a retrospective cohort study examining patients managed with biplanar external fixator knee fusion due to non-revisable iTKR between 2014 and 2018. We compared this group of patients with a historical cohort-control patient who had been previously published by our unit in 2013, since we switched from a monoplanar to a biplanar configuration for the management of this kind of complex end-stage iTKR. Primary end-points were fusion rate, time to achieve bone fusion and infection eradication rate. Limb-length discrepancy, pain level, patient satisfaction, and health-related quality of life were also evaluated. Results. A total of 29 cases were finally included; 8 patients were managed with a bilateral external fixator and 21 patients were managed with a monoplanar external fixator. In the biplanar configuration group, infection was eradicated in 100% of the patients, and fusion was achieved in all cases after 5.24 months on average. In comparison, in the monolateral configuration group, infection was eradicated in 18 (86%) out of 21, whereas fusion was achieved in 17 (81%) of the patients after a mean of 10.3 months (range, 4–16). Such difference was statistically significant (p<0.05). In both groups, postoperative pain was mild (VAS score 2,25 and 3,4, respectively) and patients expressed a high degree of satisfaction once fusion was achieved. Conclusions. External fixation knee fusion is a useful limb-salvage procedure in end-stage cases of knee PJI. According to our data, the use of a biplanar configuration allows us to reduce in half (10.3 vs 5.2 months, p<0.05) the time needed to achieve the solid bone fusion in such a complex scenario. In this cohort of previously multi-operated patients, the satisfaction is high, and the level of pain is low if a solid bone fusion free of infection is achieved