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Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_17 | Pages 1 - 1
1 Nov 2017
Lokikere N Syam K Saraogi A Siney P Nagai H Jones HW
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Introduction. Osteosynthesis to conserve femoral head following neck of femur (NOF) fractures has reported failure rates of 36 to 47% at 2 years. However, the long-term outcomes of THAs performed for failed osteosynthesis is yet to be elucidated. This study aims to report on long term outcome of primary THAs post failed osteosynthesis for NOF fracture. Methods. Consecutive patients with THA for failed NOF osteosynthesis managed by a single unit between January 1974 and December 2009 were included. Clinical and radiological outcomes of all 72 patients were analysed. Patients with minimum follow-up of 5 years were included. Those with less than 5 years of follow-up were reviewed for failures. Results. Mean age at the time of THA was 56. (range − 18–79). Mean follow-up was 12.9 years (range − 5 to 35.5). All patients had cemented THA. The major late complications included stem loosening in 4, stem fracture - 1, cup loosening - 7, deep infection − 3 and dislocations in 4. Thirteen (18.1%) patients had revisions. Cumulative survival rate is 80.3% (CI: 91.6–69.1) at 10 years. Conclusion. The outcomes for patients with THA for failed osteosynthesis post NOF fracture is worse in comparison with reported revision rates of THA for acute NOF fracture. The risks of poorer outcomes following salvage THA and morbidity of failed osteosynthesis need to be factored in for NOF fracture management


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 144 - 144
1 Apr 2019
Prasad KSRK Kumar R Sharma A Karras K
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Background. Stress fractures at tracker after computer navigated total knee replacement are rare. Periprosthetic fracture after Minimally Invasive Plate Osteosynthesis (MIPO) of stress fracture through femoral tracker is unique in orthopaedic literature. We are reporting this unique presentation of periprosthetic fractures after MIPO for stress fracture involving femoral pin site track in computer assisted total knee arthroplasty, treated by reconstruction nail (PFNA). Methods. A 75-year old female, who had computer navigated right total knee replacement, was admitted 6 weeks later with increasing pain over distal thigh for 3 weeks without trauma. Prior to onset of pain, she achieved a range of movements of 0–105 degrees. Perioperative radiographs did not suggest obvious osteoporosis, pre-existent benign or malignant lesion, or fracture. Radiographs demonstrated transverse fracture of distal third of femur through pin site track. We fixed the fracture with 11-hole combihole locking plate by MIPO technique. Eight weeks later, she was readmitted with periprosthetic fracture through screw hole at the tip of MIPO Plate and treated by Reconstruction Nail (PFNA), removal of locking screws and refixation of intermediate segment with unicortical locking screws. Then she was protected with plaster cylinder for 4 weeks and hinged brace for 2 months. Results. Retrograde nail for navigation pin site stress fracture entails intraarticular approach with attendant risks including scatches to prosthesis and joint infection. So we opted to fix by MIPO technique. Periprosthetic fracture at the top of MIPO merits fixation with antegrade nail in conjunction with conversion of screws in the proximal part of the plate to unicortical locking screws. Overlap of at least 3cms offers biomechanical superiority. She made an uneventful recovery and was started on osteoporosis treatment, pending DEXA scan. Conclusion. Reconstruction Nail (PFNA), refixation of intermediate segment with unicortical locking screws constitutes a logical management option for the unique periprosthetic fracture after MIPO of stress fracture involving femoral pin site track in computer assisted total knee replacement


Introduction. Osteosynthesis with open reduction techniques in comminuted subtrochanteric femoral fractures can further devitalise fragments and lead to increased rate of non-union, infection, and implant failure. Therefore, these fractures require indirect reduction techniques that do not further damage the vascular supply or soft tissue attachments of the fragments. Dynamic condylar screw (DCS) using indirect reduction and minimally invasive technique may be a good alternative to avoid these complications in such fractures. Material & methods. Forty-three patients with comminuted subtrochanteric fractures underwent indirect reduction and biological internal fixation with DCS. Mean age was 43.9 (range 25–65) years. There were six Seinsheimer type III, 15 type IV and 22 type V fractures. Results. All fractures united without bone grafting at average union time of 16.16 weeks (range, 13–22) weeks. There were no cases of non-union or implant failure at mean follow-up of 25.13 months. We observed technical difficulties in six patients such as: inaccurate placement of guide pin in two patients, difficulty in sliding the plate due to obesity in one patient, difficulty in gliding barrel plate over condylar screw in one patient and technical failure in a further two patients. Seven patients had mean limb length discrepancy of 1.48 cm (range, 1–2). Mean Harris hip score was 88.2 (range 80–90) points. Two patients had coxa vara and persistent limp. Discussion. Stripping of the soft tissues to the lateral cortex is kept to a minimum in indirect reduction. The vitality of the medial fragments is not further compromised since they are not exposed. Viable bone rapidly unites by callus formation. Conclusions. Osteosynthesis of comminuted subtrochanteric fractures is desirable using indirect reduction and minimally invasive technique. Dynamic condylar screw can be used based on these principles; however, proper planning and execution of the technique is required to achieve good functional outcome and to avoid complications


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 12 - 12
1 Oct 2022
Fes AF Leal AC Alier A Pardos SL Redó MLS Verdié LP Diaz SM Pérez-Prieto D
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Aim

The most frequent mechanical failure in the osteosynthesis of intertrochanteric fractures is the cut-out. Fracture pattern, reduction quality, tip-apex distance or the position of the cervico-cephalic screw are some of the factors that have been associated with higher cut-out rates. To date, it has not been established whether underlying bacterial colonization or concomitant infection may be the cause of osteosynthesis failure in proximal femur fractures (PFF). The primary objective of this study is to assess the incidence of infection in patients with cut-out after PFF osteosynthesis.

Method

Retrospective cohort study on patients with cut-out after PFF osteosynthesis with endomedullary nail, from January 2007 to December 2020. Demographic data of patients (such as sex, age, ASA), fracture characteristics (pattern, laterality, causal mechanism) and initial surgery parameters were collected (time from fall to intervention, duration of surgery, intraoperative complications). Radiographic parameters were also analyzed (tip-apex distance and Chang criteria). In all cut-out cases, 5 microbiological cultures and 1 anatomopathological sample were taken and the osteosynthesis material was sent for sonication. Fracture-related infection (FRI) was diagnosed based on Metsemakers et al (2018) and McNally et al (2020) diagnostic criteria.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 16 - 16
1 Dec 2021
Columbrans AO González NH Rubio ÁA Font-Vizcarra L Ros JM Crespo FA Colino IA Johnson MCB Lucena IC Moreno JE Cardona CG Moral E Martínez RN Duran MV
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Aim

The purpose of this study is to analyze the demographic and microbiological variables of acute ankle infections posterior to ankle osteosynthesis and to determine the different characteristics of patients withE. cloacae infection.

Method

A multicenter retrospective observational study (4 national hospitals) of acute post osteosynthesis infections of ankle fracture operated between 2015 and 2018 was implemented. The demographic and microbiological variables relating to the surgical intervention and the antibiotic treatment performed were collected. A descriptive assessment of all the variables and a univariate comparison between patients with E. cloacae infection and patients with alternative microorganism infections were performed. The SPSS v25 program for Windows was the choice for statistical analysis.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_15 | Pages 73 - 73
7 Nov 2023
Rachoene T Sonke K Rachuene A Mpho T
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Fractures of the ankle are common, and they mostly affect young adults. Wound complications are not uncommon following the fixation of these fractures. This study evaluated the impact of HIV on wound healing after plate osteosynthesis in patients with closed ankle fractures.

This is an observational retrospective study of patients operated on at a tertiary level hospital. We reviewed hospital records for patients above 18 years of age who presented with wound breakdown following ankle open reduction and internal fixation. The patients’ hospital records were retrieved to identify all the patients treated for closed ankle fractures and those who developed wound breakdown. Patients with Pilon fractures were excluded. The National Health Laboratory System (NHLS) database was accessed to retrieve the CD4 count, viral load, haematology study results, and biochemistry results of these patients at the time of surgery and subsequent follow-up. The x-rays were retrieved from the electronic picture archiving system (PACS) and were assessed for fracture union at a minimum of 3 months follow-up.

We reviewed the medical records of 172 patients with closed ankle fractures treated from 2018 to 2022. Thirty-one (18.0%) developed wound breakdown after surgery, and they were all tested for HIV. Most of the patients were male (58.0%), and the average age of the cohort was 43.7 years (range: 21 years to 84 years). Ten of these patients (32.2%) were confirmed HIV positive, with CD4 counts ranging from 155 to 781. Viral load levels were lower than detectable in 40% of these patients. All patients progressed to fracture union at a minimum of 3 months follow-up.

We observed no difference between HIV-positive and HIV-negative patients in terms of wound breakdown and bone healing post-plate osteosynthesis for closed ankle fractures.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_14 | Pages 44 - 44
1 Dec 2019
Menon A Bhadiyadra R Kuntwad V Soman R Rodrigues C Shetty A Agashe V
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Aim

Management of infection after osteosynthesis (IAO) poses a significant challenge in the setting of multidrug resistant organisms (MDRo). We have analysed whether IAO with MDRo has an adverse outcome.

Method

We have retrospectively analysed patients with IAO from January 2001 to November 2016 with a minimum follow up of 12 months after the discontinuation of antibiotics.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_16 | Pages 11 - 11
1 Dec 2015
Grytsai M Linenko O Kolov G Tsokalo V Hordii A Sabadosh V Pecherskiy A
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This article is based on the analysis of surgical treatment peculiarities of 641 patients with post-osteomyelitis long bones defects. The average age of patients at the time of hospital admission was 32,4 ± 0,7 and ranged from 4 to 70 years. Most of them were people of active working age (476 (74.3%)) and male (523 (81.1%)).

In this observation group 566 (88.3%) patients had the osteomyelitis process of the traumatic origin, including post-surgical (n = 155) and post-gunshot injuries (n = 13). Chronic hematogenous osteomyelitis was diagnosed in 75 (11.7%) patients. Most patients had lower extremity bones problems, including 444 tibia defects and 142 femoral bone defects. Much fewer patients had the osteomyelitis process of the upper extremity (humerus, radius, ulnar bone – 18, 19 and 18 respectively).

Purulent necrotic process was accompanied by nonunion bone fragments in 160 (24%) patients, delayed union in 95 (14.6%) patients, false joint in 178 (27.6%) patients, segmental bone defect in 75 (11 5%) patients and bones union with edge defects and cavities in 143 (22.3%) patients.

340 (53%) patients were operated using the method of free bone grafting, and 301 (47%) patients were operated using the distraction method.

The need to use the bilocal for external fixation on upper extremities occurs quite seldom (twice in our observations). Even when there is an upper extremity bone defect of several centimeters the preference should be given not to bilocal external fixation.

When treating the lower extremities taking the above mentioned into consideration, segmental defects predominated, that is why the bilocal distraction-compression method of surgical treatment prevailed (98.6%).

Thus, the main method of upper extremities long bones defects replacement is free bone grafting with segment fixation by the external fixation device, for lower extremities the is not-free main Ilizarov method, which allows to get positive results in 84.6% of patients with femoral bone problems and in 96.4% of tibia problems, mainly due to one-step treatment, directed simultaneously to inflammatory process elimination and maximum possible anatomical and functional restoration of the affected extremity.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_16 | Pages 5 - 5
1 Dec 2015
Grytsai M Kolov G Linenko O Tsokalo V Hordii A Sabadosh V Pecherskiy A
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Despite the increase of surgical procedures for extremities injuries and improvement of various fixation devices and surgical methods, the number of unsatisfactory osteosynthesis results reaches 2–7%. Chronic osteomyelitis after lower extremities long bones osteosynthesis occurs in 1.3–23% of cases, and the percentage of bone nonunion due to infections reaches 83%.

We conducted a retrospective analysis of 237 patient treatment with chronic osteomyelitis following tibial and femoral bone osteosynthesis. Two groups were selected for the analysis: the first group contained 194 patients treated with sheets and the second one contained 43 patients treated with intramedullary locked nails.

In cases of unconsolidated fractures and false joints, the necrectomy was performed with single-step or two-step replacement of internal fixation for external fixation. In this case segmental bone defects reached 20.9% in the first group and 3.6% in the second one. Here the treatment was performed using the Ilizarov method with the bone defect distraction replacement.

Conclusions. 1. Chronic osteomyelitis following sheets usage, unlike the osteomyelitis following the intramedullary locked osteosynthesis, leads more often to the formation of edge and segmental bone defects, which significantly prolongs the treatment duration.

2. External fixation application for postoperative osteomyelitis treatment in case of the bone nonunion made it possible to eliminate the purulent process and restore the extremity support function.

3. The inflammatory process relapses reached 14.9% in the first group and 3.1% in the second one.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_16 | Pages 39 - 39
1 Dec 2015
Branco P Paulo L Santos R Babulal J Moita M Marques T Martinho G Infante F Gonçalves L Mendes F
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This work refers to a male patient, 25 years of age, admitted in the Emergency Department following a bicycle accident, of which resulted an open fracture of the right forearm bones – Gustillo & Anderson I.

With this work, the authors have as objective the description of the patient's clinical condition – starting with the fracture, over to the osteomyelitis – as well as the surgical procedures and remaining treatments he was submitted to.

The authors used the patient's records from Hospital's archives, namely records from the Emergency Department, Operating Room, Infirmary and Consultation, and also the diagnostic exams performed throughout the patient's clinical evolution.

This clinical case began in May 2013, when the patient suffered an open fracture of the right forearm bones – Gustillo & Anderson I – due to a bicycle accident. At the time, the exposure site was thoroughly rinsed, a cast immobilization was made, and antibiotics were prescribed. In the fifth day following the trauma, the patient was submitted to an open reduction with internal fixation with plate and screws of both forearm bones. In the following period, the distal segment of the suture suffered necrosis, exposing the radial plate and the tendons of the first dorsal compartment. The Plastic Surgery team was then contacted, proposing the execution of a graft over the exposed area, which was made in August 2013. In the postoperative period, about half the graft lost its viability and it was noted that a radial pseudoarthrosis had developed – in the context of osteomyelitis – with a defect of about 9 centimeters. This condition prompted the extraction of the osteosynthesis material, about 4 months after its application, and at the same time the first stage of a Masquelet Technique was performed. The second stage of the aforementioned procedure was carried out two months later. Currently, the patient is clinically stable, with right hand mobility acceptable for his daily living activities.

Analyzing the patient's clinical evolution, we concluded that, even though the adequate therapeutic decisions have been made in each stage, the development of osteomyelitis was inevitable. This realization, in association with the patient's young age, raises debatable questions of therapeutic order.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_23 | Pages 43 - 43
1 Dec 2016
Romanò C Malizos K Blauth M Capuano N Mezzoprete R Logoluso N Drago L
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Aim

Aim of this study is to present the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating*, in patients undergoing internal osteosynthesis for closed fractures.

Method

In this prospective, multi-centre, randomized, controlled, prospective study, a total of 260 patients were randomly assigned, in five European orthopaedic centres, to receive the antibiotic-loaded DAC coating or to a control group, without coating. Pre- and post-operative assessment of laboratory tests, wound healing, clinical scores and x-rays were performed at fixed time intervals.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 289 - 289
1 Mar 2013
Ogawa K
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Introduction

Fracture of the proximal femur frequently occur in children with osteogenesis imperfecta(O.I.) or fibrous dysplasia and may lead to progressive coxa vara and a “shepherds crook” deformity. In adults, these changes introduce difficulties that are not ordinarily encountered with routine osteosynthesis. There is minimal literature on this topic and the cases reported are few in number.

Objective

The purpose of this case report was to describe a intertrochanteric fracture in a elderly woman with O.I. successfully treated by 115 degrees hip osteotomy plate and cannulated screws.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_10 | Pages 1 - 1
1 Oct 2015
Manjunath D
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Intraarticular fractures of the distal humerus comprise 1% of all fractures in adults. Triceps reflecting and olecranon osteotomy approach provide adequate exposure in intraarticular fracture with its own advantage and disadvantages. Forty consecutive patients with fractures of the distal humerus were treated over a 36-month period. The patients were randomly allotted into two groups; group A consists of twenty patients with olecranon osteotomy and group B consists of twenty patients with triceps reflecting approach. In both the groups fracture was fixed using orthogonal or parallel plating techniques. Clinical outcome was assessed using the DASH SCORE, radiological union and complications was noted in both the group and compared. In group A the mean DASH score was 15.9 points. Three patients underwent a second procedure for hardware removal, 2 patients had non-union at osteotomy site, one patient had transient ulna nerve neuropraxia and one patient had superficial infection. In group B the mean DASH score was 14 points. There was no statistical significance between both groups regarding final outcome except complications were more in osteotomy approach. We conclude both approach is an effective procedure with an excellent or good functional outcome but osteotomy approach has more complications.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_5 | Pages 57 - 57
1 Feb 2016
Ehlke M Heyland M Mardian S Duda GN Zachow S
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We present a novel method to derive the surface distance of an osteosynthesis plate w.r.t. the patient-specific surface of the distal femur based on 2D X-ray images. Our goal is to study from clinical data, how the plate-to-bone distance affects bone healing. The patient-specific 3D shape of the femur is, however, seldom recorded for cases of femoral osteosynthesis since this typically requires Computed Tomography (CT), which comes at high cost and radiation dose. Our method instead utilises two postoperative X-ray images to derive the femoral shape and thus can be applied on radiographs that are taken in clinical routine for follow-up. First, the implant geometry is used as a calibration object to relate the implant and the individual X-ray images spatially in a virtual X-ray setup. In a second step, the patient-specific femoral shape and pose are reconstructed in the virtual setup by fitting a deformable statistical shape and intensity model (SSIM) to the images. The relative positioning between femur and implant is then assessed in terms of displacement between the reconstructed 3D shape of the femur and the plate. A preliminary evaluation based on 4 cadaver datasets shows that the method derives the plate-to-bone distance with a mean absolute error of less than 1mm and a maximum error of 4.7 mm compared to ground truth from CT. We believe that the approach presented in this paper constitutes a meaningful tool to elucidate the effect of implant positioning on fracture healing.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_12 | Pages 29 - 29
1 Mar 2013
Malal JG Mayne AIW Noorani AM Kent M Smith M Guisasola I Brownson P
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The aim of the study was to assess the medium term outcome for complex proximal humeral fractures treated with the long proximal humeral internal locking system (PHILOS) plate fixation.

All patients who had long PHILOS plate fixation of proximal humerus fractures with metaphyseal or diaphyseal extension over a three year period at our institution were included in the study. Patients had their case notes and radiographs reviewed. Patients were also contacted to assess functional outcome using the Visual Analogue Scale (VAS) for pain, DASH, Oxford shoulder score (OSS) and Stanmore Percentage of Normal Shoulder Assessment (SPONSA).

Out of an initial cohort of 34 patients, 1 died, 2 patients had unrelated illnesses resulting in them being unable to complete the assessment and 6 were lost to follow-up, leaving 25 patients (74%) for review. All patients had proximal humeral fractures with metaphyseal or diaphyseal extension requiring long plate osteosynthesis. One patient had the procedure for non union following initial treatment with an intra medullary nail and the rest were acute injuries. The patients were followed up after a mean of 27 months (range 11–60). The length of plate used varied from 5 to 12 holes for the shaft region.

There was 1 wound infection. 3 patients had non unions which required bone grafting and revision internal fixation. At final follow-up, mean pain was 3.6 (95% Confidence Interval 2.5–4.8) with only 4 patients having residual pain greater than 5 on the VAS scale. Mean DASH score was 41.2 (95% CI 32.0–50.4), mean OSS was 29.1 (95% CI 24.3–33.9) and mean SPONSA was 63.9% (95% CI 50.8–77.2)

The long PHILOS plate appears to represent a good treatment option for complex proximal humerus fractures with favourable medium term results and few complications.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IV | Pages 90 - 90
1 Mar 2012
Webb J McMurtry I Port A Liow R
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Unstable fractures of the distal tibia are being increasingly treated by open reduction and internal fixation using pre-contoured locking plates. Functional outcome following this type of fixation has not been reported previously.

The aim of this study was to functionally assess patients following MIPO fixation of distal tibial fractures.

Case notes of 26 patients treated at a single centre were reviewed. The fracture type, fixation technique, complications, time to union and subsequent treatment were documented. All patients returned for functional scoring using the validated American Academy of Orthopedic Surgeons (AAOS) foot and ankle core score.

Twenty-six consecutive patients were treated between 2002-2005. The majority were male, and 5 were open fractures. There were 13 AO type A, 4 type B and 9 type C fractures. Mean follow up was 20 months. Average time from injury to surgery was 2.5 days. All fractures were treated by a MIPO technique. A pre-contoured distal locking plate was used for the distal tibial reconstruction. Secondary surgical procedures e.g. 2nd look, delayed primary closure, or skin grafting were necessary in 3 cases. The fibula was plated in 60% of cases. Four patients developed wound infections requiring antibiotics, and all resolved. The commonest rehabilitation regime was 6 weeks non weight bearing in plaster. Mean time to union was 18 weeks. There were 3 cases of delayed union, requiring bone grafting. One patient required removal of the plate due to local irritation, and one required a broken screw to be removed. Mean range of movement was 10 degrees dorsiflexion, 30 plantarflexion. The mean normalised AAOS foot and ankle core score was 41 (SD +/− 8).

We conclude that MIPO fixation of distal tibial fractures is a safe and effective method of treatment. Functional outcome does not significantly differ from that of the general population.


Purpose

To promote rapid bone healing, an adequate stable fixation implant with a percutaneous reduction instrument should be used for Vancouver type B1 or C fractures. The objective of this study was to describe radiographic and clinical outcomes of patients with periprosthetic fracture (PPF) around a stable femoral stem, treated with a distal femoral locking plate alone or with a cerclage cable.

Materials and Methods

A total of 21 patients with PPF amenable to either a reverse distal femoral locking plate (LCP DF®) alone or with a cerclage cable, with a mean age of 75.7 years, were included. In these patients, 10 fractures were treated with a reverse LCP DF® alone and were classified as group I, and 11 additionally received a cerclage cable and were classified as group II.[Fig.1]


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 152 - 152
1 Jan 2013
Lidder S Masterson S Grechenig S Pilsl U Tanzer K Clements H
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Percutaneous plating of the distal tibia via a limited incision is an accepted technique of osteosynthesis for extra-articular and simple intra-articular distal tibia fractures. In this study we identify structures are risk during this approach.

Method

Thirteen unpaired adult lower limbs were used for this study. Thirteen, 16-hole synthes®LCP anterolateral distal tibial plates were percutaneously inserted according to the manufacturer instructions and confirmed by xray. Dissection was performed around the plate to examine the relation of nerves and soft tissue.

Results

The neurovascular bundle was under the plate in one case. Over the horizontal limb of the plate, typically the superficial peroneal nerve had a variable course over all four screw holes. The anterior tibial artery coursed over hole number 3 and the Extensor hallucis longistendon was positioned over hole 3 or 4. The Anterior tibialis tendon skirted hole 4 in 12 cases. Over the vertical limb of the plate, the neurovascular bundle coursed over holes, 5 to 7, the superficial peroneal nerve over holes 5 to 7.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_1 | Pages 72 - 72
1 Jan 2016
Chen Y Chang C Chang H Chang C Lin Y
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Cannulated screw is commonly used in the fixation of proximal femoral neck fractures. In the literature, several configurations had been proposed for best mechanical support with clinical experiences or biomechanical tests. Although screws in triangle configuration contribute certain fixation stability, but sometimes the surgeons made their own choices have to conduct another fixation pattern for some factors such as fracture type, economic issues, and so on. Therefore the aim of this study is to analyze the mechanical responses of a fractured femur fixed with screws in different configurations, screw materials and screw diameters with finite element method, trying to find the most stable construct. A solid femur model was built from the CT images of a standard saw bone. Three fracture types of the femoral neck were created according to Pauwel's classification (30?, 50?, 70?) by CAD software. The models of implanted screws were built according to a commercial cannulated screw (Stryker Osteosynthesis, Schoenkirchen/Kiel, Germany) with diameter 6.5mm and 4.5mm by CAD software, too. Three fixation configurations were analyzed in this study, including triangle with superior single screw with titanium diameter 6.5mm, triangle with inferior single screw with diameter 6.5mm and diamond with four stainless screw diameter 4.5mm (fig.1). Totally there were nine models constructed in this study, and all of them were then imported into ANSYS WORKBENCH v14 (Swanson Analysis, Houston, PA, USA) to mesh and further analysis. 700N vertical downward force was applied on the femur head and the distal end of femur shaft was totally fixed. The triangle fixation with superior single screw resulted in a best stability, but the fracture fixed with screws in a diamond configuration has least fracture gap. The difference of the maximum displacement of the femur head with Pauwel's classification 70?between triangle fixation with superior single screw and diamond configuration is only 0.03mm (1.72–1.69 mm). In most unstable femoral neck fracture [Pauwel's classification 70], the maximum gap distance is 0.59mm under the diamond configuration, while it is 0.63mm as the fracture fixed with a triangle configuration. Therefore, this study suggests that four 4.5mm stainless screws in a diamond configuration is an alternative for proximal femur fracture once 6.5mm titanium screws are not available


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 110 - 110
1 Jan 2016
Oshima Y Fetto J
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Introduction. Femoral neck fracture is a common injury in elderly patients. To restore the activity with an acceptable morbidity and to decrease of mortality, surgical procedures are thought to be superior to conservative treatments. Osteosynthesis with internal fixation for nondisplaced type, and hemiarthroplasty or total hip replacement (hip arthroplasties) for displaced type are commonly performed. Cemented arthroplasty has been preferred over non-cemented arthroplasty because of less postoperative pain, better mobility and excellent initial fixation of the implant, especially for osteoporotic and stove-pipe bones. However, pressurizing bone cement may cause cardiorespiratory and vascular complications, and occasionally death, which has been termed as “bone cement implantation syndrome”. To avoid the occurrence of this syndrome, non-cemented implants have been developed. However, most implants with the press fit concepts and flat wedge taper designs have a risk of intraoperative and early postoperative periprosthetic fracture. Recently, we have employed a non-cemented femoral component, which has a lateral expansion to the proximal body as compared to a conventional hip stem. Because of this shape, which is called a “lateral flare”, this stem provides a physiological loading on both the medial and lateral endosteal surfaces of the femur. This is in contrast to conventional hip stem which prioritizes loading on the medial and metaphyseal /dyaphyseal surfaces of the femur. Moreover, the cross section of this stem is trapezoid with the flat posterior surface. This shape provides the stem with rotational stability along the long axis of the femur, and maximizes loading transfer to the posterior aspect of the proximal femur. These mechanical features avoid the need for aggressive impaction of the stem at the time of insertion. It is necessary to only tap gently to achieve the secure initial implant fixation by a “rest fit”. Thus, this technique reduces the risk of fracture. Patients and methods. We employed this technique using a non-cemented lateral flare design device for displaced femoral neck fractures since 1996. Surgical procedures were performed with posterior approach under the spinal or epidural anesthesia. Full weight bearing ambulation with a walker was allowed on post-op day one. Results and discussion. Since that time, we have had no femoral fracture, no dislocation of the hip, nor severe complications intraoperatively and post operatively. There has been no evidence of radiographic aseptic loosening or axial migration of the stems during this time period. Conclusions. “Rest fit” surgical technique avoids complications associated with cemented and traditional non-cemented arthroplasties for displaced femoral neck fractures. It however requires specific geometric features to be included the designs of the femoral component to assure secure initiate fixation at the time of arthroplasty. Therefore, this lateral flare implants are effective for the treatment of the displaced type of femoral neck fracture