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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 53 - 53
24 Nov 2023
Hanssen JL van der Linden HM van der Beek MT van der Wal RJ Termaat MF de Boer MG Scheper H
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Aim. Multidisciplinary team (MDT) management of complex bone and joint infections (BJI) is increasingly implemented but studies evaluating this approach are scarce. We assessed the effectiveness of our MDT by analyzing the adherence to its treatment decisions. Method. A cohort study was conducted comprising patients with complex BJI of which the management was discussed during MDT meetings between 2015 and 2022 in a tertiary care academic hospital. Patient characteristics and MDT data were obtained from electronic patient records. Results. The analysis included 1321 MDT case decisions on 509 patients. During the study period, the number of patients discussed by the MDT increased from 2.7 to 5.5 per meeting. The percentage of discussed patients with BJI other than prosthetic joint infections (PJI) increased from 26% to 52%. The overall adherence rate to MDT decisions was 92.1%. Reasons for non-adherence were disagreement with the MDT whether cure was achieved or not (34%), new clinical information that was not available during the MDT meeting (12%), preference for suppressive antibiotic treatment over surgery (8%) or not recorded in the patient file (46%). Conclusions. Over the years, the MDT meeting content expanded from mainly PJI to all complex BJI. The high adherence rate to MDT decisions was indicative of an effective MDT. Analysis of adherence is a useful tool to evaluate an MDT and can be used to improve its quality. Different aspects of an MDT need to be evaluated to fully determine its impact and to help improve the care for patients with complex BJI


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 20 - 20
1 Oct 2022
Scheper H Van der Wal R Mahdad R Keizer S Delfos N Van der Lugt J Veldkamp KE Nolte P Schippers E Wattel H Visser LG Nelissen R De Boer MG
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Background. Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods. In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with DAIR or one-stage revision surgery between January 1. st. , 2015 and November 3. rd. , 2020, were included. Patients were treated according to a predefined protocol for PJI. Antimicrobial treatment strategies differed between centers, which was accepted and used as pseudorandomization. Depending on the hospital patients were admitted to, they were treated with either a long-term rifampicin strategy (consisting of 12 weeks rifampicin combination therapy) ore one of several short-term rifampicin strategies, consisting of only five days of rifampicin combination treatment, started immediately postoperative, followed by clindamycin, flucloxacillin or vancomycin monotherapy. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results. Two hundred patients were included and, based on the antimicrobial treatment, stratified in one long-term rifampicin group (n=23) or one of the three short-term rifampicin groups: clindamycin (n=56), flucloxacillin (n=47), vancomycin (n=26), other (n=48). Outcome of PJI after DAIR or one-stage exchange was not statistically different between patients treated with long-term rifampicin combination therapy and patients treated with clindamycin or flucloxacillin monotherapy including only five days of rifampicin combination therapy. Moreover, treatment duration was four weeks shorter in the clindamycin-based and flucloxacillin-based groups. Adjusted hazard ratios for failure for patients treated with either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR 1.21, 95%CI 0.34–4.40). Conclusions. A short-term rifampicin strategy with either clindamycin or flucloxacillin and only five days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_6 | Pages 44 - 44
1 May 2021
Zenios M Oyadiji T Zamini-Farahani A
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Introduction. In my paediatric Orthopaedic practice I use Kirchner wires for the fixation of the TSF on bone. I noted a significant percentage of wire loosening during the post-operative period. The aim of this project was to establish the effectiveness of the wire clamping mechanism and find ways to reduce the incidence of wire loosening when using the TSF. Materials and Methods. In the first instance wire slippage was measured intra-operatively after the tensioner was removed using an intra-operative professional camera. Following this study mechanical tests were performed in the lab measuring the pull out properties of Kirchner wires using different bolts and different torque levels in order to tighten the wire on the fixator. Results. Our clinical study confirmed wire slippage intra-operatively immediately after the tensioner was removed. Wire slippage after the tensioner was removed was found to vary from 0.01 mm to 0.51 mm (mean 0.19 mm). Our mechanical tests showed that the ideal torque for tightening the wire on the frame using a bolt was around 15 N.m. A comparison between cannulated and slotted bolts suggested that cannulated bolts are more effective as a clamping mechanism. A comparison between aluminium made Taylor Spatial frame rings and stainless steel made Ilizarov rings suggested that the Taylor Spatial frame rings are more effective as part of a clamping mechanism. Conclusions. It is important that clinicians routinely measure the torque they use to clamp wires on circular external fixators. Clinicians and manufacturers are informed that the type of bolt used is important in maintaining wire tension. Manufacturers should design the ideal bolt which effectively grips the wire without the risk of fracture. The Ilizarov frame clamping mechanism can be effectively used with the Taylor Spatial frame


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_6 | Pages 6 - 6
1 May 2021
Chatterton BD Kuiper J Williams DP
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Introduction. Circumferential periosteal release is a rarely reported procedure for paediatric limb lengthening. The technique involves circumferential excision of a strip of periosteum from the metaphysis of the distal femur, tibia and fibula. This study aims to determine the mid to long-term effectiveness of this technique. Materials and Methods. A retrospective case series was performed of all patients undergoing circumferential periosteal release of the distal femur and/or tibia between 2006 and 2017. Data collected included demographics, surgical indication, post-operative limb-lengths and complications. Data collection was stopped if a further procedure was performed that may affect limb-length (except a further release). Leg-length discrepancies were calculated as absolute values and as percentages of the longer limb-length. Final absolute and percentage discrepancies were compared to initial discrepancies using a paired t-test. Results. Eighteen patients (11 males) were identified, who underwent 25 procedures. The mean age at first surgery was 5.83 (SD 3.49). The commonest indication was congenital limb deficiency (13 patients). In 23 procedures the periosteum was released in two limb segments (distal femur and distal tibia), whereas in two patients it was released in a single limb segment. Five patients underwent repeat periosteal release, and one patient had three periosteal releases. Mean follow-up was 63.1 months (SD 33.9). Fifteen patients had sufficient data for statistical analysis. The mean initial absolute discrepancy was 2.01cm (SD 1.13), and the mean initial percentage discrepancy was 4.09% (SD 2.76). The mean final absolute discrepancy was 1.00cm (SD 1.62), and the mean percentage final discrepancy was 1.37% (SD 2.42). The mean reduction in absolute discrepancy was 0.52 cm (95%CI −0.04–1.08; p=0.068, paired t-test), and the mean reduction in percentage discrepancy was 2.00% (95% CI 1.02–2.98, p=<0.001 paired t-test). In five patients the operated limb overgrew the shorter limb. Conclusions. Circumferential periosteal release produces a modest decrease in both absolute and percentage limb-length discrepancy, although the outcome is variable and some patients may experience overgrowth of the operated limb


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 342 - 342
1 Dec 2013
Hasegawa S Mizutani J Otsuka S Suzuki N Fukuoka M Otsuka T Banks S
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Introduction. Cervical orthoses are commonly used to regulate the motion of cervical spines for conservative treatment of injuries and for post-operative immobilization. Previous studies have reported the efficacy of orthoses for 2D flex-extension or 3D motions of the entire cervical spine. However, the ability of cervical orthoses to reduce motion might be different at each intervertebral level and for different types of motion (flexion-extension, rotation, lateral bending). The effectiveness of immobilizing orthoses at each cervical intervertebral level for 3D motions has not been reported. The purpose of this study is to evaluate the effectiveness of the Philadelphia collar to each level of cervical spines with 3D motion analysis under loading condition. Patients & Methods. Patient Sample Four asymptomatic volunteer subjects were recruited and provided informed consent. Approval of the experimental design by the institutional review board was obtained. These 4 individuals were without any history of cervical diseases or procedures. The presence of any symptoms, spinal disorders and anatomical abnormalities in fluoroscopic images or CT was a criterion of exclusion from this study. Outcome Measures To evaluate the efficacy of the Philadelphia collar, ANOVA was used to compare the range of motion with and without collar at the C3/4, C4/5, C5/6 and C6/7 intervertebral levels for each motion. The level of statistical significance was set at p < 0.05. When a statistical difference was detected, post hoc Tukey tests were performed. Methods. Three-dimensional models of the C3–C7 vertebrae were developed from CT scans of each subject using commercial software (see Figure 1). Two fluoroscopy systems were positioned to acquire orthogonal images of the cervical spine. The subject was seated within the view of the dual fluoroscopic imaging system (see Figure 2). Pairs of images were taken in each of 7 positions: neutral posture, maximum flexion and extension, maximum left and right lateral bending, and maximum left and right rotation. The images and 3D vertebral models were imported into biplane 2D-3D registration software, where the vertebral models were projected onto the pair of digitized images and the 3D bone pose was adjusted to match its radiographic projection in each image (see Figure 3). Relative motions between each vertebral body were calculated from body-fixed coordinate systems using a flexion-lateral bending-axial rotation Cardan angle sequence. Results. Flexion range was significantly reduced with the collar at each cervical level. Extension range was significantly reduced at the C3/4 level. Rotation and lateral bending were reduced for C3/4, C4/5, C5/6 levels with the collar. Discussion/Conclusion. The Philadelphia Collar significantly reduces cervical motion at C3/4, C4/5 and C5/6 levels in almost all motions (except for extension). At the C6/7 level, this type of collar has limited effectiveness reducing cervical motion. We used 3D radiographic measurements to quantify the effectiveness of the Philadelphia collar for reducing cervical motion. Bi-plane 2D-3D registration method is useful technique to evaluate 3D motion of cervical spines


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_21 | Pages 58 - 58
1 Dec 2016
Hassan E Tucker A Clouthier A Deluzio K Brandon S Rainbow M
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Valgus knee unloader braces are often prescribed as treatment for knee osteoarthritis (OA). These braces are designed to redistribute the loading in the knee, thereby reducing medial contact forces. Patient response to bracing is variable; some patients experience improvements in joint loading, pain, and function, others see little to no effect. We hypothesised that patients who experienced beneficial response to the brace, measured by reductions in medial contact force, could be predicted based on static and dynamic measures. Participants completed a WOMAC questionnaire and walked overground with and without an OA Assist knee brace in a motion capture lab. Eighteen patients with medial compartment OA (8 female, 53.8±7.0 years, BMI 30.3±4.1, median Kellgren-Lawrence grade 4 (range 1–4)) were evaluated. The abduction moment applied by the brace was estimated by multiplying brace deflection by the pre-determined brace stiffness. A generic musculoskeletal model was scaled for each participant based on standing full length radiographs and anatomical markers. Inverse kinematics, inverse dynamics, residual reduction, and muscle analysis were completed in OpenSim 3.2. A static optimisation was then performed to estimate muscle forces and then tibiofemoral contact forces were calculated. Brace effectiveness was defined by the difference in the first peak of the medial contact force between braced and unbraced conditions. Principal component analysis was performed on the hip, knee, and ankle angles and moments from the unbraced walking condition to extract the principal component (PC) scores for these variables. A linear regression procedure was used to determine which variables related to brace effectiveness. Potential regressors included: hip-knee-ankle angle and medial joint space measured radiographically; KL grade; mass; WOMAC scores; unbraced walking speed; and the first two principal component scores for each of the unbraced hip, knee, and ankle joint angles and moments. KL grade, walking speed, and hip adduction moment PC1, which represented the magnitude of the first peak were all found to be correlated with change in medial contact force. The brace was more successful in reducing medial contact force in subjects with higher KL grades, faster self-selected walking speeds, and larger peak external hip adduction moments. The R2 value for the overall regression model was 0.78. The best predictor of brace effectiveness was the hip adduction moment, indicating the need to consider dynamic measures. Participants who had hip adduction moments and walking speeds similar to those of their healthy counterparts saw a greater reduction in medial contact force. Thus, those who responded to bracing had more severe OA as measured by the KL grade but had not experienced changes in their hip adduction moment due to OA. The results of this study suggest that there is potential for an objective criterion for valgus knee brace use to be established


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 90 - 90
1 Jan 2013
Khan S Belcher H
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Background. Collagenase represents a novel non-surgical treatment for Dupuytrens disease. Xiapex (Injectable collagenase, Pfizer pharmaceuticals) was recently approved by the MHRA for clinical use. The main objective of this study was to assess the proportion of patients with Dupuytrens disease that are suitable for treatment with collagenase and the financial implications of its introduction. Methods. All new patients diagnosed with Dupuytrens disease over a three month period (Sept-Nov) were enrolled into study. Patients were assessed in clinic by a senior surgeon. All patients with a palpable Dupuytrens cord without significant skin tethering were offered collagenase. Comparisons were made with the corresponding quarter in the previous 2 years. Management trends were compared over the three years (2009–11) to identify the impact of collagenase. Cost effectiveness analysis was based on a comparison with costs incurred by a fasiectomy, the most common intervention in the management of Dupuytrens disease. Results. Total number of patient referrals was relatively static over the three years with a range of 269 to 285. 23 (36.9%) of 58 patients received collagenase in the time period it was available. Needle fasiotomies which accounted for 11/76 (14%) procedures in 2009 and 5.2% of procedures in 2010 was not performed once collagenase was available. There was a significant reduction in the number of fasiectomies performed over the three year period. 42% (28/58) of procedures performed were fasiectomies in 2010 this had significantly fallen to 32% (21/58) in 2011. Dermofasiectomies were stable over the three year 17% in 2009 to 13% in 2011 with the introduction of collagenase. Cost effectiveness analysis revealed a significant reduction in cost with collagenase. Conclusions. Upto 40% of patients with established Dupuytrens disease maybe suitable for management with collagenase. This represents a cost-effective, clinically effective non-surgical option in the management of Dupuytrens disease


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 66 - 66
1 Feb 2017
Chen Z Zhou Z Pei F
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Objective. To investigate the effectiveness of applying fast track surgery concept in primary total hip arthroplasty. Methods. The data of patients with primary total hip arthroplasty in our department from January 1, 2013 to October 1, 2015 were retrospectively analyzed. The patients were divided into traditional recovery group, enhanced recoverygroup and update enhanced recovery group according to different interventions. The blood loss, transfusion rate, complications rate, postoperative function, length of stay, hospitalization expense and readmission rate were compared between three groups. Results. A total of 435 cases were included. Compared with traditional recovery group, the average blood loss, length of stay and total cases of complication in update enhanced recovery group were reduced 91.44 ml, 1.34 days and 14.05%, respectively, and the differences showed statistical significance. From 2013 to 2015 the hip flexion and abduction degree increased annually, the differences also showed statistical significance. The blood transfusion rate, other complications and hospitalization expense were all reduced, but there were no statistical significance. Conclusions. The emphasis of fast track surgery concept in primary total hip arthroplasty was the management in perioperative period. Through continuous optimization of intervention measures under the guidance of evidence based medicine, it can effectively accelerate recovery, diminish complications and reduce the length of hospital stay


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XIX | Pages 17 - 17
1 May 2012
Thompson A Walter S Brunton L Pickering G Mehendale S Bannister GC
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Background. Venous thromboembolism deterrent (TED) stockings are recommended for all orthopaedic patients. Clinical evidence supporting their use is limited and the risk of DVT increases four-fold if pressure gradients are reversed. This study aims to investigate the efficacy of TED stockings and their application using pressure gradients as the outcome measure. Methods. We audited TED stockings over two discrete periods. In the first, cases were assessed for sizing, cutting in and tolerance. In the second we added pressure measurements along the saphenous vein; before and 2 and 3 days after surgery. Between the 2 series, a more rigorous sizing and re-sizing protocol was implemented. Results. In the first period, 80% of TED stockings were incorrectly sized, 48% cut in and compliance was 60%. In the second period, 34% of stockings were incorrectly sized, 20% cut in and compliance was 93%. Reverse gradients were observed in 21% of patients. Conclusion. Previous studies had shown reverse gradients in 54% of cases however we found significantly fewer (P=0.000). We attribute this to better fitting rather than quality of the stockings. The effectiveness of graduated compression stockings is more practice than device dependent


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 201 - 201
1 Jun 2012
Salehi A Snider A Mehl D
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Introduction. Hip resurfacing is a bone sparing approach to treating arthritis in younger or more active patients. Accurate positioning of the femoral component in the hip resurfacing procedure is essential for the success of the operation [1-2]. An alignment guide assisting the operator in accurately positioning the resurfacing implant may increases the success rate of the operation. This study focuses on the effectiveness of a CT based resurfacing alignment guide, shown in Figure 1. Materials and Methods. Four full fresh frozen human cadaveric specimens were CT scanned to reconstruct bone models of the femoral head/neck geometries with no cartilage included in the segmentation. Femoral head resurfacing alignment guides were then created through computer aided design (CAD) modeling using landmarks from the reconstructed bone models for proper seating. A total of 12 resurfacing alignment guides (3 for each specimen) were prepared. After the exposure of the hip joints, the first two out of three resurfacing alignment guides were used to asses the fit, stability, and visual assessment of valgus and version alignments. The third resurfacing alignment guide for each specimen was placed on the femoral head/neck region and the guide wire was drilled into the femur. A fluoroscopy image was taken to assess and measure the valgus and version alignment. The acceptance criteria for valgus alignment, as shown in Figure 2, is set to be ±2.5° from a line parallel to the medial calcar of the femoral neck, Similarly, the acceptance criteria for the version alignment was set to be ±2.5° from a line passing through the neutral axis of the femoral neck. Results and Discussion. The resurfacing alignment guides were firmly secured on the femoral head; they were stable and their auxiliary guide wire placement features were allowed for visual assessments of the alignment. The planned and the measured valgus angles were in agreement and the version alignment neutral to femoral neck axis was within the acceptable range. Current manual alignment guides require user experience for locating the entry point and trajectory for femoral head resurfacing. The CT based patient matched alignment guide offers a precise and reliable implant positioning, reducing the possibility of notching of the femoral neck and leaving any air pocket around the distal periphery of the implant which could lead to neck fracture or implant loosening, respectively. This study demonstrates the effectiveness of a guide made based on the patient specific CT scan assisting the operator in the precise alignment of the femoral implant. The potential benefits of this technology are consistent and accurate alignment of the implant, reduced OR time and ease of use with reduced instrumentation


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_1 | Pages 15 - 15
1 Jan 2022
Tamboowalla KB Gandbhir V Nagai H Wynn-Jones H Talwalker S Kay P
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Abstract

Background

The COVID-19 pandemic has strongly impacted elective orthopaedic surgery. At our trust, a geographically discrete elective site deals with planned orthopaedic surgery. There was a need to define a green pathway to deliver surgical care safely and efficiently, and tackle mounting waiting lists.

Methods

Records of patients operated at our elective site, between 1st July 2020 and 14th January 2021, under a green pathway, including pre-operative self-isolation, COVID screening and segregating perioperative patients, were reviewed, and analysed retrospectively. Patients who did not attend (DNA) their post-operative follow-up appointments were identified. Finally, regional COVID incidence was compared with that in our centre.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 563 - 563
1 Dec 2013
Tuzun HY Akyildiz F Tatar O Ozkan H Yanmis I Tunay S
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Femoroacetabular impingement (FAI) syndrome is one of the significant reasons for hip pain, loss of ROM at hip joint and developing early osteoarthritis at young active adults. FAI is not a new term and it is treated successfully with open surgical techniques. Some disadvantages of open surgical tecniques has lead orthopedists to develop arthroscopic tecniques. At this study, we aimed to assess the effectiveness of arthroscopy at the treatment of FAI. We included 25 patients (19 male, 6 female) and evaluated retrospectively which has gone under arthroscopic surgery for the treatment of FAÄ° at Gulhane Military Medicine Academy, Department of Orthopedics and Traumatology and Ankara Koru Hospital, Department of Orthopedics and Traumatology between January 2009 and May 2012. We have evaluated modified Harris Hip Score and Visual Analogue Score (VAS) preoperatively and postoperatively at all of our patients. Also we have evaluated, hip internal rotation and flexion range of motions clinically. Mean preoperative Harris Hip Score was 68,52 (range 55–76), mean postoperative score was 88,84 (range 72–98). Mean preoperative flexion ROM was 87, 6 (range 80–95) and 108,2 (range 90–120) postoperatively. Also 4,4 (range 0–5) degrees of mean preoperative internal rotation ROM increased to 19,80 range (10–30) degrees postoperatively. Mean preoperative alpha angle was 76,76 (range 60–90) and it was decreased to 41,76 (range 34–48) postoperatively. Mean preoperative visual analog score were decreased from 8, 63 to 2,8 postoperatively. We had to perform o second look arthroscopy to a patient because of inadequate resection. Also femoral neck stres fracture occured at a patient probably due to early weight bearing. Transient sciatic nevre neuropraxy occured at a 3 patients and, transient ankle pain (approximately 6 weeks) had occured at 2 patients due to traction. Loss of sensation has occured at a patient due to lateral femoral cutaneus nevre injury during portal placement. With these results, we assessed that arthroscopic treatment of the FAI syndrome is succesfull with minor complications comperable to open procedures


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 207 - 207
1 Sep 2012
Leung A Hawthorn B Simpson A
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The treatment of chronic osteomyelitis requires both appropriate surgical and antibiotic management. Prolonged intravenous antibiotic therapy followed by oral therapy is widely utilised. Despite this, the long-term recurrence rate is approximately 25%. The aim of this cohort study was to examine the effectiveness of marginal surgical resection in combination with local application of antibiotics (Collatamp G - gentamicin in a collagen fleece). Post-operatively this was followed by a short course of intravenous antibiotics, then oral antibiotics, to 6 weeks in total. A cohort of 50 patients from a 10-year period, 2000 to 2010, with chronic osteomyelitis was identified. Most were male (n= 35, 70%) and the average age is 40.9 years (SD 15.9). The mean follow-up duration was 3.2 years (SD 1.8). The average length of admission was 9.8 days (SD 11.4). 6 patients (12%) suffered recurrence of infection requiring further treatment. We used the Cierny and Mader classification to stratify the patients further. There were 24 (48%) ‘A’ hosts and 26 (52%) ‘B’ hosts. ‘A’ hosts had a shorter duration of admission (7.1 days) than ‘B’ hosts (12.3 days). There was no significant difference between recurrence rates of ‘A’ and ‘B’ hosts. The available pre-operative C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels did not predict disease recurrence. Overall, the disease-free probability for this cohort was 0.80. A similar cohort treated with prolonged systemic and oral antibiotics reported by Simpson and colleagues (JBJS Br 2001) had a disease-free probability at 0.68. Local administration of gentamicin in a collagen fleece leads to improved disease-free probability when compared with prolonged systemic antibiotic treatment. We believe this is a useful component in the management of chronic osteomyelitis


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 86 - 86
1 Feb 2017
Currier B Currier J Holdcroft L Van Citters D
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Introduction. The optimum UHMWPE orthopaedic implant bearing surface must balance wear, oxidation and fatigue resistance. Antioxidant polyethylene addresses free radicals, resulting from irradiation used in cross-linking, that could oxidize and potentially lead to fatigue damage under cycles of in vivo use. Assessing the effectiveness of antioxidant (AO) polyethylene compared to conventional gamma-sterilized or remelted highly cross-linked (HXL) polyethylene is necessary to set realistic expectations of the service lifetime of AO polyethylene in the knee. This study evaluates what short-term antioxidant UHMWPE retrievals can reveal about: (1) oxidation-resistance, and (2) fatigue-resistance of these new materials. Methods. An IRB-approved retrieval laboratory received 25 AO polyethylene tibial insert retrievals from three manufacturers with in vivo time of 0–3 years. These were compared with 20 conventional gamma-inert sterilized and 30 HXL (65-kGray, remelted) tibial inserts of the same in vivo duration range. The retrievals were. (1) analyzed for oxidation and trans-vinylene index (TVI) using an FTIR microscope, and (2) inserts of sufficient size and thickness were evaluated for mechanical properties by uniaxial tensile testing using an INSTRON load frame. Oxidation was reported as maximum oxidation measured in the scan from the articular surface to the backside of each bearing. TVI was reported as the average of all scans for each material. Average ultimate tensile strength (UTS), ultimate elongation (UE), and toughness were the reported mechanical properties for each material. Results. Maximum oxidation values differed significantly across material types (p=0.018, Figure 1). No antioxidant retrieval exhibited a subsurface oxidation peak, in contrast to conventional gamma-sterilized (55%) and highly cross-linked (37%) retrievals that exhibited subsurface oxidation peaks over the same in vivo time (Figure 2). Trans-vinylene index (TVI) correlated positively with nominal irradiation dose (p<0.001). Mechanical properties varied by material, with tensile toughness correlating negatively with increasing TVI (p<0.001, Figure 3). Discussion. AO polyethylene was developed to address the problem of free radicals in polyethylene resulting from irradiation used in cross-linking or sterilization. Each manufacturer used a different antioxidant or method of supplying the antioxidant. However, all of the antioxidant materials appeared to be effective at minimizing oxidation over the in vivo period of this study. The antioxidant materials prevented in vivo oxidation more effectively than both conventional gamma-sterilized and remelted HXL polyethylene, at least over the in vivo period represented. The toughness, or ability of the material to resist fatigue damage, decreased with increasing irradiation cross-linking dose (increasing TVI). The AO polyethylenes evaluated in this study had lower toughness than conventional gamma-sterilized polyethylene, but they avoided the loss of toughness due to remelting. Clinical relevance. Antioxidant polyethylene tibial retrievals showed superior oxidation resistance to conventional gamma-inert and remelted HXL inserts. Material toughness varied with the irradiation dose used to produce the material. Comparison of antioxidant retrieval tensile properties can be used as a guide for clinicians in choosing appropriate materials for the applications represented by their patients


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_1 | Pages 77 - 77
1 Jan 2016
Cho S Youm Y Kim J
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Purpose. To evaluate the effectiveness of post-operative pain management using the intra-operative peri-articular injection(PAI) and/or electromyography (EMG)-guided preoperative femoral nerve block (FNB) in total knee arthroplasty(TKA). Materials and Methods. From March 2013 to February 2014, 90 knees which underwent primary TKA by one surgeon were included in our study. The patients were classified into three groups; a single injection FNB with an EMG guide (Group I, 30 knees), intra-operative PAI (Group II, 30 knees) and both FNB and PAI (Group III, 30 knees). Pain at rest and moving was evaluated by Visual Analogue Scale (VAS) at postoperative 0, 4, 8, 24 and 48 hours. Postoperative range of motion, time to walking, total blood loss, amount of opioid consumption and complications were compared in each group. Results. VAS immediately after surgery was 67.9 in group I, 54.6 in group II and 54.7 in group III. VAS was significantly higher in group I than group II and III (p=0.005), but was not significantly different between group II and III (p>0.05). VAS at postoperative 4 and 8hr showed similar results. VAS at postoperative 24 hr was 49.6 in group I, 56.4 in group II and 46.7 in group III, which was significantly higher in group II than group I and III (p=0.043). After postoperative 48hr, there were no differences in group I, II and III. The total amount of opioid consumption in group III was smaller than that in group I and II (p=0.017). There were no differences in postoperative range of motion, time to walking and total blood loss. There was one case with temporary peroneal nerve palsy in group II and no infection in all cases. Conclusion. PAI was more effective than FNB for early (0∼8hr) postoperative period after TKA. However, PAI showed rebound pain at 24hr after TKA. PAI in combination with FNB could enhance the effect of postoperative pain management from immediate postoperative period to 24hr


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 40 - 40
1 Jan 2013
Bhattacharyya R Wallace W
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Introduction. Health Economists in Denmark have recently reported low and delayed return to work for patients treated for Sub-Acromial Impingement syndrome (SAIS) by Arthroscopic Sub-Acromial Decompression (ASAD). Surgeons however are reporting that patients achieve good pain relief and a high standard of activities of daily living (ADL) after surgery. Aim. To evaluate the effectiveness of ASAD for patients with SAIS and correlate clinical outcome with rate of return to work. Methods. Prospective cohort study and retrospective review of data from the Nottingham Shoulder database (presentation: 01/04/2008–30/06/2011). Inclusion criteria: Patients diagnosed clinically with SAIS by an experienced shoulder surgeon, who have failed conservative treatment (physiotherapy and sub-acromial injection), undergoing ASAD. Pre-operative and 6-month follow-up Oxford Shoulder Score (OSS) and Constant Score (CS) were compared. The rates of return to pre-operative level of work were also analysed. Statistical analysis: Wilcoxon signed rank test. Results. 73 patients with OSS (51 also with CS documentation) were included. The improvement in median OSS between pre-operative (24) and 6-month follow-up (39) was +15 (Z = −6.726, ∗∗∗, T=6, r=0.55). The difference in median CS between pre-operative (39) and 6-month follow-up (67) was +28 (Z=−5.435, T=6, r=0.59, ∗∗∗). Improvement in median pain score was +5 (7,12, ∗∗∗) median ADL was +5.5 (10.5,16, ∗∗∗) median ROM was +13 (18,31, ∗∗∗) and median strength was +4 (3,7, ∗∗∗). 76% returned to their pre-operative level of work (mean time = 11.5 weeks post surgery). 79% returned to their pre-operative hobbies (mean time = 11.8 weeks post surgery). Conclusion. There is a significant improvement in OSS and CS, 6 months after ASAD in patients with SAIS who have had previous failed conservative treatment. The rate of return to work was good for these patients in contrast to that reported for Danish patients. (∗∗∗ = p< 0.0001 = Highly statistically significant)


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 146 - 146
1 Sep 2012
Naqvi G Malik S Adamec O
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Aim. The aim of this study is to assess the effectiveness of clinic based ultrasound screening by Orthopaedic surgeon for early diagnosis and treatment of developmental dysplasia of hip (DDH) in one stop clinic. Methods. This prospective study included 395 infants (185 male and 210 female) (5.2% of study population) who were referred for screening on the basis of abnormal findings or the presence of risk factors for DDH. Average age was 12.5 weeks (1 day to 15 months). All infants were assessed for risk factors of DDH. Clinical examinations were performed by the senior author followed by ultrasonography of both of the infant's hips, using the Graf's technique. Alpha and beta angles were calculated and hips were classified according to Graf's classification system. Results. Out of 790 hips examined 670 (84.8%) were labelled as normal. 120 (15.1%) hips in 84 patients were diagnosed as dysplastic or dislocated. Clinical examination only detected 39 patients out of 84, sensitivity of 46%. Average age of diagnosis was 12 weeks (3days-11 months). 79 patients were successfully treated with pavlic harness, 2 required traction and 3 were referred for surgical treatment. There were 14 cases of late diagnosis during one year period (> 4 months of age) (1.8/1000). Conclusion. Selective ultrasound screening is effective in early diagnosis of DDH and significantly reduces the duration of non operative treatment as well as the need for surgical intervention but does not completely eliminate late diagnosis of DDH. We find the concept of one stop DDH clinic highly effective and recommend that ultrasound training should be a part of orthopaedic curriculum


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 79 - 79
1 Jul 2020
Legault J Beveridge T Johnson M Howard J MacDonald S Lanting B
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With the success of the medial parapatellar approach (MPA) to total knee arthroplasty (TKA), current research is aimed at reducing iatrogenic microneurovascular and soft tissues damage to the knee. In an effort to avoid disruption to the medial structures of the knee, we propose a novel quadriceps-sparing, subvastus lateralis approach (SLA) to TKA. The aim of the present study is to compare if a SLA can provide adequate exposure of the internal compartment of the knee while reducing soft tissue damage, compared to the MPA. Less disruption of these tissues could translate to better patient outcomes, such as reduced post-operative pain, increased range of motion, reduced instances of patellar maltracking or necrosis, and a shorter recovery time.

To determine if adequate exposure could be achieved, the length of the skin incision and perimeter of surgical exposure was compared amongst 22 paired fresh-frozen cadaveric lower limbs (five females/six males) which underwent TKA using the SLA or MPA approach. Additionally, subjective observations which included the percent of visibility of the femoral condyles and tibial plateau, as well as the patellar tracking, were noted in order to qualify adequate exposure. All procedures were conducted by the same surgeon. Subsequently, to determine the extent of soft tissue damage associated with the approaches, an observational assessment of the dynamic and static structures of the knee was performed, in addition to an examination of the microneurovascular structures involved. Dynamic and static structures were assessed by measuring the extent of muscular and ligamentus damage during gross dissection of the internal compartment of the knee. Microneurovascular involvement was evaluated through a microscopic histological examination of the tissue harvested adjacent to the capsular incision.

Comparison of the mean exposure perimeter and length of incision was not significantly different between the SLA and the MPA (p>0.05). In fact, on average, the SLA facilitated a 5 mm larger exposure perimeter to the internal compartment, with an 8 mm smaller incision, compared to the MPA, additional investigation is required to assert the clinical implications of these findings. Preliminary analysis of the total visibility of the femoral condyles were comparable between the SLA and MPA, though the tibial plateau visibility appears slightly reduced in the SLA. Analyses of differences in soft tissue damage are in progress.

Adequate exposure to the internal compartment of the knee can be achieved using an incision of similar length when the SLA to TKA is performed, compared to the standard MPA. Future studies should evaluate the versatility of the SLA through an examination of specimens with a known degree of knee deformity (valgus or varus).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 154 - 154
1 May 2012
S. S P. K M. U
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Background. Staphylococcus epidermidis is one of the main organisms associated with prosthetic joint infections. One of the major pathogenic attributes of this organism is the ability to form biofilms, making it extremely resistant to currently available antimicrobial therapies. There is, therefore, an urgent requirement for novel agents that are effective against this organism. Antimicrobial peptides represent a novel group of agents that show good activity towards biofilm-forming S. epidermidis. Antimicrobial peptides are particularly interesting due to their multiple modes of action which are thought to reduce the rate of resistance development to the agents. Aim. The aim of the current study was to assess the effect of antimicrobial peptides gallidermin and novel peptide NI01 on the growth of reference and clinical isolates of S. epidermidis on polymethylmethacrylate (PMMA) cement following incorporation of the peptides. Methods. To do this a novel biofilm flow-through model was used to determine the effect of the peptides on growth of the strains, allowing the assessment of planktonic and biofilm cells. The antimicrobial peptides were incorporated into 4mm diameter PMMA beads (1% w/w) created using a specially developed poly (tetrafluoroethylene) (PTFE) mould. Results. 10 beads were used per housing unit for each of the different treatments. Each of the 10 beads was inoculated with 6 × 10. 8. cfu/ml of S. epidermidis reference strain RP62a and clinical isolates 53 and 156. The growth of the strains was then monitored over a period of five days and the effect of the peptides assessed. Results identified both gallidermin and NI01 caused a significant decrease in the growth of S. epidermidis reference strain RP62a and clinical isolates 53 and 156 (P=< 0.05). Conclusion. This study identifies the effectiveness of antimicrobial peptides gallidermin and novel antimicrobial peptide NI01 against biofilm forming S. epidermidis and highlights their potential use in the orthopaedic setting


Introduction. Pain control following total knee arthroplasty (TKA) heavily influences timing of mobilization and rehabilitation postoperatively as well as length of hospital stay. Recently, periarticular injection of liposomal bupivacaine (EXPAREL®; Pacira Pharmaceuticals, Inc., San Diego, California) has demonstrated pain relief comparable to femoral nerve block for postoperative analgesia in TKA with earlier mobilization and shortened hospital stay. In order to better explore the use of EXPAREL® in TKA, we standardized the postoperative analgesia to intraoperative periarticular injection of multimodal pain management, which is a recommended postoperative method of pain control in TKA. We studied the effectiveness of periarticular EXPAREL® in TKA postoperative pain control, including impact on early mobilization and length of hospital stay, compared to another local analgesic (Ropivacaine) when both are used as part of a multimodal pain management approach. Methods. We performed a double blind, randomized, controlled, prospective, IRB-approved study that enrolled 96 participants who underwent a unilateral TKA by one surgeon between May 2014 and March 2015. The two randomized groups were as follows: group 1 (control group) was given the standard intra-articular “pain cocktail” injection, consisting of ropivacaine, ketorolac, morphine, and epinephrine mixed with saline into a 100cc preparation and group 2 (study group) was given a similar intra-articular injection consisting of bupivacaine, ketorolac, morphine, and epinephrine mixed with saline into an 80cc preparation as well as an injection of EXPAREL®, 20cc of 1.3% EXPAREL®, to total 100cc. All patients included in the study were determined to be opioid naïve as described by the Food and Drug Administration criteria. Patients were treated with the same postoperative pain management protocol as well as the same post-operative physical therapy program. The consumption of oral and intravenous narcotics at specific time points as well as total use was recorded during hospital stay. We recorded Visual Analog Pain scores, hours to ambulate 100 feet and length of hospital stay (hours). Both the investigator and the patient were blinded as to which group the patient was randomized, making this a double blind study. Results. On a per hour basis, the mean use of narcotics of the two groups differed by only 0.1mg. For total narcotic use during hospital stay, the weighted sum used by patients in the EXPAREL® group, 97.7mg of hydrocodone ±42.84 mg, exceeded the weighted sum, 89.6 mg of hydrocodone ± 58.57 mg, used by patients in the control group. The difference between the two groups was not significant. The means for length of stay differed by only 26 minutes and the difference was not significant. Similarly insignificant, the means for the time to ambulate 100 feet differed by 53 minutes, with the EXPAREL® group actually taking the longer time. The two groups did not differ for Visual Analog Score for pain on day 1 or day 2 post-operatively. Conclusion. When comparing the use of EXPAREL® to another multimodal pain management approach using ropivacaine, there is no difference in post-operative opioid consumption, Visual Analong Scores for pain, amount of time to ambulate or length of hospital stay