Background. Established hip and knee arthroplasty registers exist in many countries but this is not the case with spinal implants. Moreover, in the case of a rod intended to guide spinal growth in a child and then be removed, the definition of ‘failure’ (revision) used for hip or knee arthroplasty is inappropriate. How can the performance of such spinal implants be judged?. Methods. Ninety-six MAGnetic Expansion Control (MAGEC) spinal rods were obtained from multiple centres after removal from the spines of 52 children with scoliosis. Clinical details were assessed and divided between unplanned revision operations (‘failures’) and those which were planned. Of the explanted rods, 49 were tested for the amount of force they could output, using the manufacturer's supplied test jig. Sixty-five rods were cut apart so that the internal components (bearings, O-ring seals, drive pins) could be assessed, alongside if there was evidence of internal wear. Results. Seventy-four per cent of revision operations were unplanned. Eighty per cent of explanted rods were unable to produce the force expected from a new rod. All rods (100%) that were successfully cut open showed signs of internal wear. Non- functional bearings were seen in 74% of cases, obvious seal damage in 57% of cases and broken drive pins in 47% of cases. Conclusion. Despite potential clinical benefits, explanted MAGEC rods showed consistent and substantial damage. The majority of rods showed zero force output and most revision operations were unplanned. Independent explant analysis allows appraisal of new technology in arthroplasty for patient benefit

A growing number of children are being implanted with magnetically controlled growing rods. Some also have baclofen pumps, a device that delivers a neuromodulating medication using a magnet. There has been no previous testing to determine if the External Remote Controller (ERC) would stall the baclofen pump during magnetic rod lengthening, a potentially life-threatening event. Two baclofen pumps, 20 mL and 40 mL, were placed in varying proximity to the ERC while the magnetic field was generated. The speed (dose) of the baclofen pump, the distance from the ERC, the length of time the ERC was run, the position of the pump in relationship to the magnetic field, and the presence or absence of a stall were recorded. To stall a baclofen pump, the ERC needed to be running continuously for at least 30 mm of lengthening (about 3 minutes). The pump would not stall if it was more than 1 cm away from the ERC, even if the ERC generated a field for 3 minutes. The speed of the pump did not affect the instance of a motor stall. The pump was more likely to stall if it was positioned in front of or behind the magnetic field, as opposed to the center of the field. Baclofen pumps are always more than 1 cm away from the magnetic rods when both are implanted in a child. The typical lengthening interval is under 10 mm, much less than what was required to stall a baclofen pump. The ERC is highly unlikely to stall a baclofen pump during a magnetic rod lengthening, making a life-threatening event almost impossible

In orthopaedic spine surgery pedicle screw systems are used for stabilisation of the spine after injuries or disorders. With an percutaneous operation method surgeons are faced with huge challenges compared to an open surgery, but it's less traumatic and the patient benefits with a faster rehabilitation and less traumatic injuries. The screw positions and the required rod dimensions for the stabilising connection between the screws are hard to define without an open view on the operating field. Because of these facts a new smart device based system for rod shape determination was invented. Therefore, an application was developed, which integrates a localiser module to get the position data of the pedicle screws, with help of rigid bodies placed on top of the pedicle screws down-tubes. An algorithm was developed to choose the best fitting rod to connect the pedicle screws with help of calculating the rod length and the rod radius. The system was tested in a test scenario where four pedicle screws were drilled into a wooden plate. The positions of the screws were adjusted to fit a curved and a straight rod. In the test scenario the application chose always the rod correctly

Despite the myriad new spinal instrumentation systems, scoliosis can rarely be fully corrected, especially when the curves are stiff. A novel superelastic nickel-titanium (nitinol) rod that maximises the ability to slowly correct spinal deformities by utilising the viscoelastic properties of the spine has been developed. This parallel, double-blinded, randomised controlled trial compared the safety and efficacy of these new rods to conventional titanium rods in 23 patients with adolescent idiopathic scoliosis. The superelastic nitinol rods were found to be safe, could gradually correct scoliosis curves, and ultimately resulted in better coronal and sagittal alignments compared to traditional rods. Despite the myriad new spinal instrumentation systems, scoliosis can rarely be fully corrected, especially when the curves are stiff. A novel superelastic nickel-titanium (nitinol) rod that maximises the ability to slowly correct spinal deformities by utilising the viscoelastic properties of the spine has been developed. This parallel, double-blinded, randomised controlled trial compared the safety and efficacy of these new rods to conventional titanium rods in 23 patients with adolescent idiopathic scoliosis. The superelastic nitinol rods were found to be safe, could gradually correct scoliosis curves, and ultimately resulted in better coronal and sagittal alignments compared to traditional rods

Purpose. Failure resulting from a recurrent infection in total knee arthroplasty (TKA) is a challenging problem. Knee arthrodesis is one treatment option, however fusion is not always successful, as there is huge bone defect. The authors reports a new arthrodesis technique that uses a bundle of flexible intramedullary rods and an antibiotic-loaded cement spacer. Methods. There were 13 cases of arthrodesis due to recurrent periprosthetic joint infection, which were performed by the first author (WS Cho) at Asan Medical Center in Seoul from 2005 to 2014. All previous prosthetic components were removed and cement was thoroughly excised using a small osteotome. Two stage operation was done in most of cases. After thorough debridement, antibiotics loaded cement was inserted in first stage, flexible intramedullary rods were inserted retrogradely in the femoral side with the knee in flexion under fluoroscopy guidance. After filling the femoral intramedullary canal, the rods were then driven back securely into the tibial medullary canal. We aimed for as much rod length as possible to maximize stability. After 6 weeks of first stage operation, the rods of the femoral and tibial sides were arranged such that they overlapped and interdigitated to maximize mechanical strength, maintain the limb length and keep the rotational alignment. The interdigitating rod ends were tightly fixed using two (or three) cerclage wires. Antibiotic-loaded cement was filled into the knee joint space so that the cement is fit to the irregular contour of the femur and tibia, which was resulted from the severe bone loss. Postoperatively, patients were allowed to weight bear as tolerated. Results. The procedure was successful in every cases with no evidence of rod or cement failure at least 1 year follow up. Also there was no recurrence of infection. Conclusion. Although this simple method was not for bony union, the authors could achieve stable knee joint without recurrence of infection

Purpose of study. The aim is to assess the use of non-fusion instrumentation “growth rods” in early onset scoliosis (EOS). Methods. A retrospective review of 12 consecutive patients who had undergone a growth rod procedure for EOS was performed. Six patients had neuromuscular scoliosis, 5 had juvenile idiopathic scoliosis while one had a congenital aetiology. Growth constructs were predominately constructed from modular commercially available sets using hooks, screws and connection blocks. One VEPTR was used in a severe kyphoscoliosis. Patients returned to theatre at 6 monthly intervals for a lengthening procedure. Patients were assessed with regards to age at presentation, age at surgery, indications for surgery, initial Cobb angle, post- operative Cobb angle, number of lengthening's done, instrumentation used, amount of spine growth achieved and complications. Results. The average age at presentation was 3 yrs 8 months (birth – 7 years 5 months). The average Cobb angle was 55 (38–90). Age at index surgery ranged from 2yrs 9 months to 8 years 2 months. The Cobb angle after the first procedure averaged 37 (range 20–90). The average lengthening over 51 lengthening procedures was 8 mm. Four patients have reached the end of the process and under gone a definitive fusion with pedicle screws and growth rods. Their final Cobb angle averaged 32 (26–48). Definitive surgery was performed earlier than planned in one patient due to repetitive rod breakage. Lengthening was abandoned in one patient whose implants became septic and required removal. Two patients required revision for superior construct failure. Conclusion. The growth rod procedure allows spinal deformity correction and control as well as on-going growth in trunk height. It is a labour intensive process with a significant incidence of complications. There is however very little choice in these patients due to concerns of fusion restricting pulmonary development. NO DISCLOSURES

Introduction:. One method of femoral head preservation following avascular necrosis (AVN) is core decompression and Tantalum Rod insertion. There is, however, a published failure rate of up to 32% at 4 years. The purpose of the present study was to document the clinical and radiological outcome following Total Hip Arthroplasty (THA) subsequent to failed Tantalum Rod insertion. Methods:. Twenty-five failed Tantalum Rod insertions subsequently requiring THA were identified from a prospectively updated database. Seventeen patients met minimum 2 year clinical and radiographic follow-up criteria. St. Michael's Hip (SMH) scores were compared to a matched cohort of patients with THA for AVN without prior Tantalum Rod insertion. Postoperative radiographs were reviewed assessing component alignment, linear wear (Dorr & Wan) and presence of tantalum residue within the joint space. Results:. Nine females and eight males underwent removal of a Tantalum Rod with subsequent THA between May 2005 and March 2010. The mean time between Tantalum Rod insertion and conversion to THA was 23 months (range 6–48) with a mean follow-up of 3.5 years (range 2–5). At each follow-up interval the mean SMH scores were comparable between the two groups (p = 0.445). Femoral stem alignment (p = 0.428) and acetabular cup inclination (p = 0.723) were comparable between groups. Articular tantalum residue was identified in 12 of 17 articulations (7 mild, 3 moderate, 2 severe). Linear wear rates were comparable between the tantalum group (0.07 mm/yr, range 0.01–0.40) and controls (0.07 mm/yr, range 0.02–0.21, p = 0.951). There was no evidence of catastrophic wear. Conclusion:. Tantalum rod conversion to THA in the young adult patient with AVN reveals no early catastrophic sequelae. In the short term, Tantalum Rod insertion does not demonstrate a deleterious effect on subsequent total joint replacement surgery. There is, however, a high rate of retained tantalum debris within the effective joint space with the procedure and thus there is an unknown risk of accelerated articular wear necessitating longer term study

Purpose. Management of early onset scoliosis (EOS) can be very challenging. Surgery is indicated when orthotics and casting fail. Growing rod instrumentation has become an effective approach in controlling the deformity while allowing spinal growth. However, as with any surgery, there are known complications including failure of the proximal foundation. We analyzed our patients who underwent growing rod instrumentation and identified factors that were correlated with proximal foundation failure. Method. Our Pediatric Orthopaedic Spine Database (1992–2010) was reviewed for all patients who underwent growing rod instrumentation. Sixty-six patients with EOS were identified and divided into two groups: Group 1 – proximal foundation failure; and Group 2 – no incidents of proximal failure. The two groups were evaluated for differences in age, sex, weight, upper vertebral level in construct, presence of apical fusion, and pre-operative curve magnitude. Results. Eight of the 66 patients (12%) had proximal foundation failure. When comparing Group 1 and Group 2, only age, pre-operative kyphosis, and presence of apical fusion were significant differences between the two groups. The mean age of Group 1 patients was 4.9 years (range, 2.6 to 9.2 years) and the mean age of Group 2 patients was 7.5 years (range, 2.4 to 11.6 years) (p <0.006). The mean pre-operative kyphosis in Group 1 was 71 degrees compared to 50 degrees in Group 2 (p=0.049). Among the 12 patients with apical fusion, four (33%) had proximal failure. The presence of apical fusion was also a significant difference between the groups (p=0.003). Linear regression demonstrated a significant correlation between kyphosis and failure (k=0.005, p-value 0.016) as well as age and pullout (k=−0.005, p-value <0.01). Conclusion. Our data indicates that younger patients with increased pre-operative kyphosis are at a higher risk for proximal failure of their growing rods resulting in increased incidence of unplanned surgeries. The presence of an apical fusion was also correlated to increased failure rates possibly due to stress at the proximal construct. Further research is needed to determine if stronger constructs decrease the pullout rate in the at-risk patients

Elongating rods have been used in the management of Osteogenesis Imperfecta (OI) for the last 50 years; complication rates have been high in many reviews of available techniques. The functional outcomes and complications of a cohort of 22 Osteogenesis Imperfecta patients treated with 66 Sheffield Telescopic Intramedullary Rods at an average of 19 years post-initial surgery are analysed. The revision rate was 35% for any reason, 20% excluding revisions for rods separating due to growth. Re-operation other than revisions occurred in 10 rods (15%). Mobility was significantly better in the initial post-operative period (p=0.0015), this difference maintained in adulthood (p=0.0077). Back pain was the most frequent symptom. Symptoms related to the insertion technique across the knee and ankle were rare but those related to femoral trochanteric entry were common. Physeal damage following surgery was not experienced and all rods elongated. All patients were satisfied with the outcome of their surgeries. SF-36 scores were significantly different for physical functioning domains, social functioning and vitality in comparison to normal population values, but comparable to other studies of OI. The outcomes of this technique are satisfactory in adulthood; re-operation rates are high but related mainly to outgrowing the rods. Concerns regarding insertion with this fixed device at the knee and ankle are not founded, although proximal femoral fixation remains a problem

Background. The new Fassier-Duval Telescopic IM System (FD-rod) has the advantage of a single entry point over the traditional telescopic rods such as the Bailey-Dubow or Sheffield rods. Although encouraging early results were presented by François Fassier, there is no formal publication in the literature as yet. Methods. The first 24 consecutive cases (age 1.5-12.5 years) with a minimum of 1 year follow-up (1-2.4 years) after femoral and/or tibial FD-rods were reviewed to assess complications involving migration, non-telescoping, joint intrusion, infections and re-operation rates in patients with Osteogenesis imperfecta (OI, 15 cases), congenital tibial pseudarthrosis (CPT) in Neurofibromatosis Type1 (NF1, 2 cases), and Epidermal Naevus syndrome (1 case). In 6 cases of patients with Hypophosphataemic Rickets FD-rods were combined with an Ilizarov frame. Results. The OI patient group had a 13% re-operation rate (2/15) for proximal rod migration and a 40% complication rate (6/15 cases): rod migration and limited telescoping (5), intra-operative joint intrusion (1). There were no infections. All NF1 CPT (2) and Epidermal Naevus syndrome (1) cases required several re-operations for non-union, loss of fixation, shortening (negative telescoping), migration and/or joint intrusion – mainly due to the severe underlying pathology with insufficient longitudinal or torsional stability and diminished healing capacity. The 6 cases with Hypophosphataemic Rickets, combined with Ilizarov frame fixation, had a 50% complication rate (3/6) and a 17% re-operation rate (1/6): 2 cases did not telescope and 1 case of peroneal neuropraxia required neurolysis. Conclusion. In our experience the technique of using Fassier-Duval rods is demanding and associated with some intra- and post-operative pitfalls. We are happy to continue its use in OI patients when there is longitudinal stability and sufficient bone healing. However, in circumstances of insufficient stability and bone healing potential, further stabilisation e.g. with an Ilizarov frame may be beneficial

Purpose of Study

To see if the addition of a locking plate to FD rod fixation of osteogenesis imperfecta confers extra strength and allows earlier mobilisation.

Children with osteogenesis imperfecta (OI) frequently present with coxa vara (CV). Skeletal fragility, severe deformity and limited fixation options make this a challenging condition to correct surgically. Our study aimed to determine the efficacy of the Fassier technique to correct CV and determine the complication rate. Retrospective, descriptive case series from a tertiary hospital. We retrospectively reviewed records of a cohort of eight children (four females, 12 hips) with OI (6/8 Sillence type III, 2/8 type IV) who had surgical treatment with Fassier technique for CV between 2014 and 2020. Inclusion Criteria: All patients with CV secondary to OI treated surgically with Fassier technique. Exclusion Criteria: Patients older than 18 years; Patients with CV treated non-operatively or by surgical technique different to Fassier technique. Data relating to the following parameters was collected and analyzed: demographic data, pre- and postoperative neck shaft angle (NSA), complications and NSA at final follow-up. The mean age at operation was 5.8 years (range 2–10). The mean NSA was corrected from 96.8° preoperatively to 137º postoperatively. At a mean follow-up of 38.6 months, the mean NSA was maintained at 133°, and 83% (10/12) of hips had an NSA that remained greater than 120°. There was a 42% (5/12) complication rate: three Fassier–Duval rods failed to expand after distal epiphyseal fixation was lost during growth; one Rush rod migrated through the lateral proximal femur cortex with recurrent coxa vara; and one Rush rod migrated proximally and required rod revision. The Fassier technique effectively corrected CV in children with moderate and progressively deforming OI. The deformity correction was maintained in the short term. The complication rate was high, but mainly related to the failed expansion of the Fassier–Duval rods

The purpose of this study is to evaluate risk factors for distal construct failure (DCF) in posterior spinal instrumented fusion (PSIF) in adolescent idiopathic scoliosis (AIS). We observed an increased rate of DCF when the pedicle screw in the lowest instrumented vertebra (LIV) was not parallel to the superior endplate of the LIV, however this has not been well studied in the literature. We hypothesise a more inferiorly angled LIV screw predisposes to failure and aim to find the critical angle that predisposes to failure. A retrospective cohort study was performed on all patients who underwent PSIF for AIS at the Starship Hospital spine unit from 2010 to 2020. On a lateral radiograph, the angle between the superior endplate of the LIV was measured against its pedicle screw trajectory. Data on demographics, Cobb angle, Lenke classification, instrumentation density, rod protrusion from the most inferior screw, implants and reasons for revision were collected. Of 256 patients, 10.9% (28) required at least one revision. The rate of DCF was 4.6% of all cases (12 of 260) and 25.7% of revisions were due to DCF. The mean trajectory angle of DCF patients compared to all others was 13.3° (95%CI 9.2° to 17.4°) vs 7.6° (7° to 8.2°), p=0.0002. The critical angle established is 11°, p=0.0076. Lenke 5 and C curves, lower preoperative Cobb angle, titanium only rod constructs and one surgeon had higher failure rates than their counterparts. 9.6% of rods protruding less than 3mm from its distal screw disengaged. We conclude excessive inferior trajectory of the LIV screw increases the rate of DCF and a screw trajectory greater than 11° predisposes to failure. This is one factor that can be controlled by the surgeon intraoperatively and by avoiding malposition of the LIV screw, a quarter of revisions can potentially be eliminated

Aim

Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity. Currently, due to the global burden of multidrug-resistant Gram-negative bacteria (MDR-GNB) infections, few multicentre studies have described a microbiological shift from Gram-positive cocci (GPC) towards MDR-GNB PJI (prosthetic joint infection). Additionally, the emergence of MDR-GNB impacts the therapeutic options and may increase the rate of PJI treatment failure. The purpose of the present study was to describe the predisposing factors associated to failure of treatment in an orthopaedic reference hospital in Brazil from 2014 through 2019.

In posterior fixation for deformity correction and spinal fusion, there is increasing discussion around auxiliary rods secured to the pedicle screws, sharing the loads, and reducing stresses in the primary rods. Dual-rod, multiaxial screws (DRMAS) provide two rod mounting points on a single screw shaft to allow unique constructs and load-sharing at specific vertebrae. These implants provide surgical flexibility to add auxiliary rods across a pedicle subtraction osteotomy (PSO) or over multiple vertebral levels where higher bending loads are anticipated in primary rods. Other options include fixed-angle devices as multiple rod connectors (MRC) and variable-angle dominoes (VAD) with a single-axis rotation in the connection. The objective in this simulation study was to assess rod bending in adult spinal instrumentation across an osteotomy using constructs with DRMAS, MRC, or VAD multi-rod connections. The study was performed using computer biomechanical models of two adult patients having undergone posterior instrumented spinal fusion for deformity. The models were patient-specific, incorporating the biomechanics of the spine, have been calibrated to assess deformity correction and intra- and postoperative loads across the instrumented spine. One traditional bilateral-rod construct was used as a control for six multi-rod configurations. Spinal fixation scenarios from T10 through S1 with the PSO at L4 were simulated on each patient-specific model. The multi-rod configurations were bilateral and unilateral DRMAS at L2 through S1 (B-DRMAS and U-DRMAS), bilateral DRMAS at L3 and L5 (Hybrid), bilateral MRC over L3-L5, bilateral and unilateral VAD over L3-L5 (B-VAD and U-VAD). Postoperative gravity plus 8-Nm flexion and extension loads were simulated and bending moments in the rods were computed and compared. In the simulated control for each case (#1 & #2), average rod bending moments (of the right and left rods) at the PSO level were 6.7Nm & 5.5Nm, respectively, in upright position, 8.8Nm & 7.3Nm in 8-Nm flexion, and 4.6Nm & 3.7Nm in 8-Nm extension. When the primary rods of the multi-rod constructs were normalized to this control, the bending moments in the primary rods of Case #1 & #2 were respectively 57% & 58% (B-DRMAS), 54% & 62% (B-VAD), 60% & 61% (MRC), 72% & 69% (Hybrid), 81% & 70% (U-DRMAS), and 81% & 73% (U-VAD). Overall, the reduction in primary rod bending moments ranged from 19–46% for standing loads. Under simulated 8-Nm functional moments, the primary rod moments were reduced by 18–46% in flexion and 17–48% in extension. More rods and stiffer connections produced the largest reductions for the primary rods, but auxiliary rods had bending moments that varied from 49% lower to 13% higher than the primary ones. Additional rods through DRMAS, MRC, and VAD connections noticeably reduced the bending loads in the primary rods compared with a standard bilateral-rod construct. Yet, bending loads in the auxiliary rods were higher or lower than those in the primary rods depending on the 3D spinal deformity and stiffness of the auxiliary rod connections. Additional studies and patient-specific analyses are needed to optimize instrumentation parameters that may improve load-sharing in these constructs

Introduction. Osteogenesis imperfect (OI) is a geno- and phenotypically heterogeneous group of congenital collagen disorders characterized by fragility and microfractures resulting in long bone deformities. OI can lead to progressive femoral coxa vara from bone and muscular imbalance and continuous microfracture about the proximal femur. If left untreated, patients develop Trendelenburg gait, leg length discrepancy, further stress fracture and acute fracture at the apex of the deformity, impingement and hip joint degeneration. In the OI patient, femoral coxa vara cannot be treated in isolation and consideration must be given to protecting the whole bone with the primary goal of verticalization and improved biomechanical stability to allow early loading, safe standing, re-orientation of the physis and avoidance of untreated sequelae. Implant constructs should therefore be designed to accommodate and protect the whole bone. The normal paediatric femoral neck shaft angle (FNSA) ranges from 135 to 145 degrees. In OI the progressive pathomechanical changes result in FNSA of significantly less than 120 degrees and decreased Hilgenreiner epiphyseal angles (HEA). Proximal femoral valgus osteotomy is considered the standard surgical treatment for coxa vara and multiple surgical techniques have been described, each with their associated complications. In this paper we present the novel technique of controlling femoral version and coronal alignment using a tubular plate and long bone protection with the use of teleoscoping rods. Methodology. After the decision to operate had been made, a CT scan of the femur was performed. A 1:1 scale 3D printed model (AXIAL3D, Belfast, UK) was made from the CT scan to allow for accurate implant templating and osteotomy planning. In all cases a subtrochanteric osteotomy was performed and fixed using a pre-bent 3.5 mm 1/3 tubular plate. The plate was bent to allow one end to be inserted into the proximal femur to act as a blade. A channel into the femoral neck was opened using a flat osteotome. The plate was then tapped into the femoral neck to the predetermined position. The final position needed to allow one of the plate holes to accommodate the growing rod. This had to be determined pre operatively using the 3D printed model and the implants. The femoral canal was reamed, and the growing rod was placed in the femur, passing through the hole in the plate to create a construct that could effectively protect both the femoral neck and the full length of the shaft. The distal part of the plate was then fixed to the shaft using eccentric screws around the nail to complete the construct. Results. Three children ages 5,8 and 13 underwent the procedure. Five coxa vara femurs have undergone this technique with follow-up out to 62 months (41–85 months) from surgery. Improvements in the femoral neck shaft angle (FNSA) were av. 18. o. (10–38. o. ) with pre-op coxa vara FNSA av. 99. o. (range 87–114. o. ) and final FNSA 117. o. (105–125. o. ). Hilgenreiner's epiphyseal angle was improved by av. 29. o. (2–58. o. ). However only one hip was restored to <25. o. In the initial technique employed for 3 hips, the plates were left short in the neck to avoid damaging the physis. This resulted in 2 of 3 hips fracturing through the femoral neck above the plate at approximately 1 year. There were revisions of the 3 hips to longer plates to prevent intra-capsular stress riser. All osteotomies united and both intracapsular fractures healed. No further fractures have occurred within the protected femurs and no other repeat operations have been required. Conclusions. Surgical correction of the OI coxa vara hip is complex. Bone mineral density, multiplanar deformity, a desire to maintain physeal growth and protection of the whole bone all play a role in the surgeon's decision making process. Following modifications, this technique demonstrates a novel method in planning and control of multiplanar proximal femoral deformity, resulting in restoration of the FNSA to a more appropriate anatomical alignment, preventing long bone fracture and improved femoral verticalization in the medium term follow-up

Fracture related infection, in particular chronic osteomyelitis, requires complex management plans. Meta analyses and systematic reviews have not found a gold standard of treatment for this disease. In 2017 an alternative treatment protocol was undertaken in our institution; whereby staged surgery with the use of cheaply manufactured tailored antibiotic cement rods was used in the treatment of chronic osteomyelitis, secondary to traumatic long bone fractures. Short term outcomes for this protocol demonstrated a 75.7% microbiological resolution to a negative culture and a good clinical outcome of 84.2% overall was demonstrated in terms of sinus resolution, skin changes, pain and function. Our aim now was to assess the long term outcomes of this treatment strategy. A cross-sectional study of patients who had previously undergone the set treatment protocol was performed. Patient satisfaction, effects on activities of daily living, return to work and clinical improvement at 5 years following the intervention were assessed using a patient questionnaire and the validated AAOS lower limb score. The average AAOS lower limb score was 88 which was en par to other similar studies. 80% of patients had returned to some form of work. Ongoing mild pain was a persistent problem for 50% of the patients however 98% of the patients were overall satisfied with the treatment satisfaction at 5 years. Only 1 patient required further treatment. 8 patients could not be located for follow up. Chronic osteomyelitis remains a complex disease to treat. This treatment protocol demonstrates favourable microbiological, serological and clinical short term outcomes and favourable patient satisfaction and functional long term outcomes at 5 years. Our study highlights antibiotic targeted cement rods as a feasible treatment option in managing chronic osteomyelitis

The use of intramedullary implants in Osteogenesis Imperfecta (OI) patients to treat and prevent fractures, non-unions and limb deformities has been well established. To serve this purpose different implants are available from non-telescoping rods such as Rush rods and Kirschner wires, to telescoping rods such as the Dubow-Bailey rod, the Sheffield rod and the Fassier-Duval (FD) rod (Pega Medical, Laval, Quebec, Canada). The purpose of this study is to report on the long-term results of the femoral Fassier-Duval rod. A retrospective chart review of all patients with OI who underwent a femoral intramedullary Fassier-Duval rodding between 2002 and 2017 and followed for an average of 12 years at the Shriner's Hospital, Montreal, Quebec, Canada was performed. A total of 81 patients underwent femoral FD rodding between 2002 and 2017. Twenty-seven children undergoing 83 procedures had completed a minimum 10-year follow up with complete charts and these were included here. The average follow up time was 12 years (10–15 years). Fifty procedures were initial rodding surgeries and 30 (36.1%) were revision surgeries. A total of 69 complications were reported in the medical record and confirmed on x-ray. The 3 most common complications were a bent rod 24 (34.8%), femur fracture 16 (23.2%) and loss of telescoping in 12 (17.4%) of patients. The 3 most common cause of revision were femur fracture 16 (53.3%), broken rod 5 (16.7%) and coxa vara in 3 (10%) of patients. The average time from initial surgery to the first revision was 5.9 years. Long term performance of femoral FD rodding shows that despite improved functioning with these rods, certain complications are to be expected, most commonly a risk of femoral fracture requiring revision surgery

Aim. Antimicrobial suppression has shown to significantly improve treatment success of streptococcal periprosthetic joint infection (PJI) compared to 12-week standard antimicrobial therapy, however, only short-term follow-up was investigated. In this study we assessed the impact of suppression on the long-term outcome of streptococcal PJI. Method. Consecutive patients with streptococcal PJI (defined by EBJIS criteria) treated 2009–2021 were prospectively included and allocated into standard and suppression (> 6 months) treatment group. Infection-free survival was assessed with Kaplan-Meier-method and compared between the groups with log rank test. Rates of infection-free, streptococcal infection-free and relapse-free status as well as tolerability of suppression were assessed. Results. Sixty-three PJI episodes (36 knee, 26 hip and one shoulder prosthesis) of patients with a median age of 70 (35–87) years were included. Twenty-seven (43%) were females. Predominant pathogens were S. agalactiae (n=20), S. dysgalactiae (n=18) and S. mitis/oralis (n=13). The main surgical procedures used were two-stage exchange (n=35) and prosthesis retention (n=21). Standard 12-week treatment was administered in 33 patients and suppression in 30 patients, of whom 10 had ongoing suppression and 20 had discontinued antibiotics at time of follow-up. Used oral antibiotics for suppression were amoxicillin (n=29), doxycycline (n=5) and clindamycin (n=2); 6 patients changed antibiotic substance due to side effects. The median follow-up time was 3.9 (0.3–13.3) years. Infection-free survival after 7.5 years was 38% with standard treatment and 62% with suppression (p=0.038). Of all failures, 52% (14/27) were due to streptococci. Suppression was effective in preventing streptococcal infection for the duration of antimicrobial treatment, however, after discontinuation relapses or new infections due to streptococci occurred in 5/20 (25%) patients and infection with any Streptococcus spp. was observed in 9/19 (47%) failures with standard treatment, 5/6 (83%) failures after discontinuing suppression and none during suppression. All failures in patients with ongoing suppression were caused by gram-negative rods. Conclusion. At long-term follow-up, the success rate was superior with suppression compared to standard treatment. Most failures after stopping suppression were caused by streptococci, whereas failures under suppression were caused by aerobic gram-negative rods

Introduction. During revision surgery, the active electrode of an electrocautery device may get close to the implant, potentially provoking a flashover. Incidents have been reported, where in situ retained hip stems failed after isolated cup revision. Different sizes of discoloured areas, probably induced by electrocautery contact, were found at the starting point of the fracture. The effect of the flashover on the implant material is yet not fully understood. The aim of this study was to investigate the fatigue strength reduction of Ti-6Al-4V titanium alloy after electrocautery contact. Material and Methods. 16 titanium rods (Ti-6Al-4V, extra low interstitial elements, according to DIN 17851, ⊘ 5 mm, 120 mm length) were stress-relief annealed (normal atmosphere, holding temperature 622 °C, holding time 2 h) and cooled in air. An implant specific surface roughness was achieved by chemical and electrolytic polishing (Ra = 0.307, Rz = 1.910). Dry (n = 6) and wet (n = 6, 5 µl phosphate buffered saline) flashovers were applied with a hand-held electrode of a high-frequency generator (Aesculap AG, GN 640, monopolar cut mode, output power 300 W, modelled patient resistance 500 Ω). The size of the generated discoloured area on the rod's surface - representative for the heat affected zone (HAZ) - was determined using laser microscopy (VK-150x, Keyence, Japan). Rods without flashover (n = 4) served as control. The fatigue strength of the rods was determined under dynamic (10 Hz, load ratio R = 0.1), force-controlled four-point bending (FGB Steinbach GmbH, Germany) with swelling load (numerical bending stress 852 MPa with a bending moment of 17.8 Nm) until failure of the rods. The applied bending stress was estimated using a finite-element-model of a hip stem during stumbling. Metallurgical cuts were made to analyse the microstructure. Results. The control rods failed at the pushers of the setup (median: 94,550, range: 194,000 cycles). The rods with flashover failed directly at the HAZ significantly earlier than the control rods (p = 0.018). The analysis of the microstructure showed a transformation of the equiaxed α+β microstructure to a bimodal state. The size of the HAZs were equal for the dry (median: 1.51 mm. 2. , range: 5.68 mm. 2. ) and wet flashovers (median: 0.92 mm. 2. , range: 2.50 mm. 2. , p = 0.792). The cycles to failure were smaller for the dry flashover (median: 22,650 cycles, range: 5,700) than the wet flashover but not reaching statistical significance (median: 32,200, range: 57,900; p = 0.052). No correlation between the dimension of the HAZs and the cycles to failure was found (dry: r. 2. = 0.019, p = 0.8; wet: r. 2. = 0.015, p = 0.721). Discussion. Flashovers induced by an electrocautery device reduce the fatigue strength of Ti-6Al-4V. Since no correlation between the size of the HAZs and the cycles to failure was found, every contact between electrocautery devices and metal implants should be avoided. For any figures or tables, please contact authors directly