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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 39 - 39
23 Feb 2023
Jo O Almond M Rupasinghe H Jo O Ackland D Ernstbrunner L Ek E
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Neer Type-IIB lateral clavicle fractures are inherently unstable fractures with associated disruption of the coracoclavicular (CC) ligaments. A novel plating technique using a superior lateral locking plate with antero-posterior (AP) locking screws, resulting in orthogonal fixation in the lateral fragment has been designed to enhance stability. The purpose of this study was to biomechanically compare three different clavicle plating constructs. 24 fresh-frozen cadaveric shoulders were randomised into three groups (n=8 specimens). Group 1: lateral locking plate only (Medartis Aptus Superior Lateral Plate); Group 2: lateral locking plate with CC stabilisation (Nr. 2 FiberWire); and Group 3: lateral locking plate with two AP locking screws stabilising the lateral fragment. Data was analysed for gap formation after cyclic loading, construct stiffness and ultimate load to failure, defined by a marked decrease in the load displacement curve. After 500 cycles, there was no statistically significant difference between the three groups in gap-formation (p = 0.179). Ultimate load to failure was significantly higher in Group 3 compared to Group 1 (286N vs. 167N; p = 0.022), but not to Group 2 (286N vs. 246N; p = 0.604). There were no statistically significant differences in stiffness (Group 1: 504N/mm; Group 2: 564N/mm; Group 3: 512N/mm; p = 0.712). Peri-implant fracture was the primary mode of failure for all three groups, with Group 3 demonstrating the lowest rate of peri-implant fractures (Group 1: 6/8; Group 2: 7/8, Group 3: 4/8; p = 0.243). The lateral locking plate with orthogonal AP locking screw fixation in the lateral fragment demonstrated the greatest ultimate failure load, followed by the lateral locking plate with CC stabilization. The use of orthogonal screw fixation in the distal fragment may negate against the need for CC stabilization in these types of fractures, thus minimizing surgical dissection around the coracoid and potential complications


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 83 - 83
1 Dec 2022
Bornes T Kubik J Klinger C Altintas B Dziadosz D Ricci W
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Tibial plateau fracture reduction involves restoration of alignment and articular congruity. Restorations of sagittal alignment (tibial slope) of medial and lateral condyles of the tibial plateau are independent of each other in the fracture setting. Limited independent assessment of medial and lateral tibial plateau sagittal alignment has been performed to date. Our objective was to characterize medial and lateral tibial slopes using fluoroscopy and to correlate X-ray and CT findings. Phase One: Eight cadaveric knees were mounted in extension. C-arm fluoroscopy was used to acquire an AP image and the C-arm was adjusted in the sagittal plane from 15° of cephalad tilt to 15 ° of caudad tilt with images captured at 0.5° increments. The “perfect AP” angle, defined as the angle that most accurately profiled the articular surface, was determined for medial and lateral condyles of each tibia by five surgeons. Given that it was agreed across surgeons that more than one angle provided an adequate profile of each compartment, a range of AP angles corresponding to adequate images was recorded. Phase Two: Perfect AP angles from Phase One were projected onto sagittal CT images in Horos software in the mid-medial compartment and mid-lateral compartment to determine the precise tangent subchondral anatomic structures seen on CT to serve as dominant bony landmarks in a protocol generated for calculating medial and lateral tibial slopes on CT. Phase Three: 46 additional cadaveric knees were imaged with CT. Tibial slopes were determined in all 54 specimens. Phase One: Based on the perfect AP angle on X-ray, the mean medial slope was 4.2°+/-2.6° posterior and mean lateral slope was 5.0°+/-3.8° posterior in eight knees. A range of AP angles was noted to adequately profile each compartment in all specimens and was noted to be wider in the lateral (3.9°+/-3.8°) than medial compartment (1.8°+/-0.7° p=0.002). Phase Two: In plateaus with a concave shape, the perfect AP angle on X-ray corresponded with a line between the superiormost edges of the anterior and posterior lips of the plateau on CT. In plateaus with a flat or convex shape, the perfect AP angle aligned with a tangent to the subchondral surface extending from center to posterior plateau on CT. Phase Three: Based on the CT protocol created in Phase Two, mean medial slope (5.2°+/-2.3° posterior) was significantly less than lateral slope (7.5°+/-3.0° posterior) in 54 knees (p<0.001). In individual specimens, the difference between medial and lateral slopes was variable, ranging from 6.8° more laterally to 3.1° more medially. In a paired comparison of right and left knees from the same cadaver, no differences were noted between sides (medial p=0.43; lateral p=0.62). On average there is slightly more tibial slope in the lateral plateau than medial plateau (2° greater). However, individual patients may have substantially more lateral slope (up to 6.8°) or even more medial slope (up to 3.1°). Since tibial slope was similar between contralateral limbs, evaluating slope on the uninjured side provides a template for sagittal plane reduction of tibial plateau fractures


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 70 - 70
23 Feb 2023
Gupta S Smith G Wakelin E Van Der Veen T Plaskos C Pierrepont J
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Evaluation of patient specific spinopelvic mobility requires the detection of bony landmarks in lateral functional radiographs. Current manual landmarking methods are inefficient, and subjective. This study proposes a deep learning model to automate landmark detection and derivation of spinopelvic measurements (SPM). A deep learning model was developed using an international multicenter imaging database of 26,109 landmarked preoperative, and postoperative, lateral functional radiographs (HREC: Bellberry: 2020-08-764-A-2). Three functional positions were analysed: 1) standing, 2) contralateral step-up and 3) flexed seated. Landmarks were manually captured and independently verified by qualified engineers during pre-operative planning with additional assistance of 3D computed tomography derived landmarks. Pelvic tilt (PT), sacral slope (SS), and lumbar lordotic angle (LLA) were derived from the predicted landmark coordinates. Interobserver variability was explored in a pilot study, consisting of 9 qualified engineers, annotating three functional images, while blinded to additional 3D information. The dataset was subdivided into 70:20:10 for training, validation, and testing. The model produced a mean absolute error (MAE), for PT, SS, and LLA of 1.7°±3.1°, 3.4°±3.8°, 4.9°±4.5°, respectively. PT MAE values were dependent on functional position: standing 1.2°±1.3°, step 1.7°±4.0°, and seated 2.4°±3.3°, p< 0.001. The mean model prediction time was 0.7 seconds per image. The interobserver 95% confidence interval (CI) for engineer measured PT, SS and LLA (1.9°, 1.9°, 3.1°, respectively) was comparable to the MAE values generated by the model. The model MAE reported comparable performance to the gold standard when blinded to additional 3D information. LLA prediction produced the lowest SPM accuracy potentially due to error propagation from the SS and L1 landmarks. Reduced PT accuracy in step and seated functional positions may be attributed to an increased occlusion of the pubic-symphysis landmark. Our model shows excellent performance when compared against the current gold standard manual annotation process


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 81 - 81
1 Dec 2013
Iguchi H Mitsui H Murakami S Watanabe N Tawada K Nozaki M Goto H Kobayashi M Otsuka T
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Introduction. We have been developed lateral flare stem and have been using it since 1989. It was custom stem at first. After being experienced, using the same software, off-the-shelf version lateral flare stem (Revelation) was developed in 1996 in the U.S. We could start using it since 2001 in our country. Lateral flare stems are designed to reproduce physiological proximal load transfer lateral side as well as medial side. It was obtained by having bigger and more accurate proximal part with lateral flare. The design is optimized by matching with 3D insertion path. Using many custom stems including different length and off-the-shelf standard stems, we have come to feel that as for this high proximal fit and load transfer design, it is not necessary to having long distal part and sometimes it is harmful to obtain good proximal load transfer in some situation such as type A (champagne flute) canal. So we have developed short version of the stem. Many makes of the hip stems have included short stems recently. Some aimed to improve easier insertion, some aimed to improve the volume of residual bone quantity. We have aimed to improve proximal fit expecting more proximal and more physiological load transfer to the femur. Objectives. Our objectives are to comare standard stem and short stem from biomechanical aspect and clinical aspect. Materials and methods. As for the biomechanical aspect, finite element analyses were done with standard and short stem. As for the clinical aspect, the very last 25 cases of the standard stems; which we have 12 years clinical experience; done at Nagoya City University, the very first 25 cases of the short stems, and the next 25 cases were examined. The distance between stem and cortical bone on medial and lateral side at lateral flare hight of the stem and the bottom of arc deposite coated area. Alignment was assessed by the angle of the stem and canal axis. Result. By the FEA, small stress point was observed at the tip of the standard stem which pushes canal wall from inside (Fig. 1), which was disappeared at the tip of the short stem. Less micromotion was observed in short stem too. No significant difference was observed in the stem cortical distance. No significant difference of stem alignment was observed between standard stem and all 50 short stems but better alignment (p = 0.07) was seen in the second 25 cases of the short stem than standard stem. Between the first 25 and the second 25 case high difference (p = 0.01) was seen. (Fig. 2). Discussion. The standard lateral flare stem has very physiological proximal load transfer in most of the cases, sometimes longer distal part could effect to the alignment because of the femoral bending. Short stem could be expected have better alignment being free from femoral bending. On the contrary, distal part could be the insertion guide during the surgery. For the short stem, learning curve exists to realize potentially better alignment


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_1 | Pages 14 - 14
1 Jan 2022
Chotai N Green D Zurgani A Boardman D Baring T
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Abstract. Aim. The aim of this study was to present the results of treatment of displaced lateral clavicle fractures by an arthroscopically inserted tightrope device (‘Dogbone’, Arthrex). Methods. We performed a retrospective series of our patients treated with this technique between 2015 and 2019. Patients were identified using the ‘CRS Millennium’ software package and operation notes/clinic letters were analysed. We performed an Oxford Shoulder Score (OSS) on all the patients at final follow-up. Our electronic ‘PACS’ system was used to evaluate union in the post-operative radiographs. Results. We treated 26 patients with displaced lateral clavicle fractures between 2015 and 2019. There were 4 patients who were treated with a ‘dogbone’ and supplementary plate fixation and the remaining 22 were treated with a ‘dogbone’ alone. Radiological union was seen in 22 (84%) patients. The mean Oxford Shoulder Score (OSS) was 46. Apart from one patient who required removal of the superior endobutton and knot under local anaesthetic there was no other secondary surgery. There were no cases of infection, nerve injury or frozen shoulder. Conclusions. Arthroscopic ‘dogbone’ treatment of lateral clavicle fractures is a safe, cosmetically friendly technique with promising high rates of fracture union and return to normal function. We recommend its use over the more conventional treatment of a hook plate


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 9 - 9
1 Mar 2021
Gagne O Veljkovic A Wing K Penner M Younger A
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Recent advances in arthroplasty for the hip and the knee have motivated modern foot and ankle research to perfect the implant and technique for the optimal total ankle replacement. Unlike in the hip where different approaches can be done with similar implants, the approach of a total ankle is intimately associated to the prosthetic design. The anterior and lateral approaches have pros and cons regarding their respective soft tissue complications, osteotomy necessity, orientation of the bone cut and gutter visualization. While both have been studied independently, very few reports have compared both in the same setting. This study retrospectively looked at the difference in reoperations rate after each ankle arthroplasty within two years estimating that both had similar rate of return to the operating room. A retrospective study was conducted from a single center between 2014 and 2017 including a total of 115 total ankles performed by one of four fellowship-trained foot and ankle surgeon. Re-operations were reported in the charts as an operative report. The index approach used was determined by the surgeon's practice preference. Patients were included when they had a primary TAR in the timeframe noted and had a complete dataset up to at least the two-year data. This cohort comprised 67 anterior and 48 lateral with balanced demographic for age (95%CI 63–67 yo) and gender (47% F). The lateral group had more complex cases with higher COFAS type arthritis. Comparing the two groups, a total of 40 reoperations (7 anterior, 33 lateral) occurred in 27 patients (5A, 22L). One patient had up to four related reoperations. The only revision was in the anterior group. The only soft tissue reconstruction was an STSG in the lateral group. Nine reoperations were irrigation debridement related to an infective process (3 A, 6L). The majority (19/33) of reoperations in the lateral group were gutter debridement (8) or lateral hardware removal (11). Operative time was not statistically different. The odds ratio of having a reoperation with a laterally based TAR was 6.19 compared to the anterior group. This retrospective study outlines the intermediate results at two years of lateral and anterior total ankle replacements. This is a first study of this kind in the literature. This study did show that there were more reoperations after a laterally-based TAR than an anterior TAR, recognizing the significant case complexity imbalance between groups. This speaks to the relative increase resource utilization of laterally based TAR patients. Both implant designs carry different reoperation rates favoring the anterior group however larger prospective datasets will be needed with patient-reported outcome


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 59 - 59
1 Dec 2022
Hiemstra LA Bentrim A Kerslake S Lafave M
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The Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0) is a patient-reported disease-specific quality of life (QOL) outcome measure used to assess patients with recurrent lateral patellofemoral instability (LPI) both pre- and post-operatively. The purpose of this study was to compare the BPII 2.0 to four other relevant patient reported outcome measures (PROMs): the Tampa Scale-11 for kinesiophobia (TSK-11), the pain catastrophizing scale (PCS), a general QOL (EQ-5D-5L), and a return to sport index (ACL-RSI). This concurrent validation sought to compare and correlate the BPII 2.0 with these other measures of physical, psychological, and emotional health. The psychological and emotional status of patients can impact recovery and rehabilitation, and therefore a disease-specific PROM may be unable to consistently identify patients who would benefit from interventions encompassing a holistic and person-focused approach in addition to disease-specific treatment. One hundred and ten patients with recurrent lateral patellofemoral instability (LPI) were assessed at a tertiary orthopaedic practice between January and October 2021. Patients were consented into the study and asked to complete five questionnaires: the BPII 2.0, TSK-11, PCS, EQ-5D-5L, and the ACL-RSI at their initial orthopaedic consultation. Descriptive demographic statistics were collected for all patients. A Pearson's r correlation coefficient was employed to examine the relationships between the five PROMs. These analyses were computed using SPSS 28.0 © (IBM Corporation, 2021). One hundred and ten patients with a mean age of 25.7 (SD = 9.8) completed the five PROMs. There were 29 males (26.3%) and 81 females (73.6%) involving 50% symptomatic left knees and 50% symptomatic right knees. The mean age of the first dislocation was 15.4 years (SD = 7.3; 1-6) and the mean BMI was 26.5 (SD = 7.3; range = 12.5-52.6) The results of the Pearson's r correlation coefficient demonstrated that the BPII 2.0 was statistically significantly related to all of the assessed PROM's (p. There was significant correlation evident between the BPII 2.0 and the four other PROMs assessed in this study. The BPII 2.0 does not explicitly measure kinesiophobia or pain catastrophizing, however, the significant statistical relationship of the TSK-11 and PCS to the BPII 2.0 suggests that this information is being captured and reflected. The preliminary results of this concurrent validation suggest that the pre-operative data may offer predictive validity. Future research will explore the ability of the BPII 2.0 to predict patient quality of life following surgery


Introduction. Both cross and lateral pinning are common techniques used for displaced supracondylar elbow fractures in children. Our study aims to determine whether there are any radiological differences in outcome between the two techniques. Most recent studies involving radiological evaluation of supracondylar fractures had concentrated on use of Bauman's angle or humerocapitellar angles. Rotational displacement, which has been shown to be critical for stability, is often not adequately addressed. Our evaluation measures both linear displacement using Bauman's angle and rotational displacement through the measurement of the lateral rotational percentage (LRP). Method. We retrospectively reviewed the radiographs of all type III supracondylar fractures reduced with either crossed pins (one medial and one lateral, one medial and two lateral) or lateral pins (two or three lateral) between 2002 and 2006 at the Royal Children's Hospital. A good quality AP and lateral radiograph taken preoperatively, immediately postoperatively, and at the first follow up session was required for patients to be included in the study. Those that had LRP change of greater than 10% were further investigated. Results. 66 of the 184 patients identified with type III supracondylar fracture with k wire fixation had adequate radiographs for the study. Thirty-three in the lateral pinning group and 33 in the cross pinning group. Results using Mann-Whitely test show nil significant differenced between the crossed and lateral pinned groups in terms of both Bauman's (p value 0.5767) angle and Lateral Rotational Profile (p value 0.063). Those that had LRP change were further investigated. The results showed that there was no difference between the cross pinning and lateral pinning in carrying angle or range of motion by the time of their last follow up. Conclusion. There is no significant difference in terms of the rate of loss of reduction radiologically using either the lateral pinning or crossed pinning method for treatment of type III supracondylar fractures in children


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 18 - 18
1 Dec 2021
Warren J Anis H Bowers K Villa J Pannu T Klika AK Piuzzi N Colon-Franco J Higuera-Rueda C
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Aim. Several options to standardize the definition of periprosthetic joint infection (PJI) have been created including the 2013 Musculoskeletal Infection Society (MSIS), 2018 Intentional Consensus Meeting (ICM), and the 2019 proposed European Bone and Joint Infection Society (EBJIS) criteria. Synovial fluid biomarkers have been investigated in an effort to simplify and improve the diagnosis of PJI. The aim of this study was to test the sensitivity, specificity, positive, and negative predicted values (PPV and NPV, respectively) of a calprotectin point of care (POC) test for diagnosing PJI in revision total knee arthroplasty (TKA) patients comparing different sets of criteria (2013 MSIS, 2018 ICM, and 2019 EBJIS criteria) used to define patients as with or without infection. Method. From October 2018 to January 2020 and under IRB approval 123 intraoperative samples of synovial fluid were prospectively collected at two academic hospitals in the same institution from revision TKA patients. All patients underwent standard clinical and laboratory evaluation for PJI at our institution, allowing for categorization using the 3 criteria. Patients were adjudicated by 2 blinded and independent reviewers for the 3 sets of criteria. The 3 criteria agreed 91.8% of the time. Four likely cases by the 2019 proposed EBJIS were considered unlikely and 1 inconclusive case by the 2018 ICM was considered not infected for the purposes of analysis. Calprotectin POC testing followed manufacturer's instructions using a threshold of >50 mg/L to indicate PJI. Sensitivities, specificities, PPV, NPV, and areas under the curve (AUC) were calculated for the 3 sets of criteria. Results. Using 2013 MSIS criteria the calprotectin POC test demonstrated a sensitivity, specificity, PPV, NPV AUC of 98.1%, 95.7%, 94.5%, 98.5%, and 0.969, respectively. Using 2018 ICM the POC test demonstrated a sensitivity, specificity, PPV, NPV and (AUC) of 98.2%, 98.5%, 98.2%, 98.5%, and 0.984, respectively. Using the 2019 proposed EBJIS criteria the POC test demonstrated a sensitivity, specificity, PPV, NPV and area under the curve (AUC) of 93.2%, 100.0%, 100.0%, 94.2%, and 0.966, respectively. Conclusions. The calprotectin lateral flow POC test has an excellent sensitivity and specificity regardless of the set of criteria used to define PJI. These results are promising and suggest that the calprotectin lateral flow test may be used as a rule out test in a cost-conscious health care model or when conventional diagnostic tools may not be available. Further investigations of the calprotectin PCO test must be completed to validate these results


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_5 | Pages 35 - 35
1 Apr 2022
See CC Al-Naser S Fernandes J Nicolaou N Giles S
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Introduction. Metabolic bone disease encompasses disorders of bone mineralization, abnormal matrix formation or deposition and alteration in osteoblastic and osteoclastic activity. In the paediatric cohort, patients with metabolic bone disease present with pain, fractures and deformities. The aim was to evaluate the use of lateral entry rigid intramedullary nailing in lower limbs in children and adolescents. Materials and Methods. Retrospective review was performed for an 11-year period. Lower limb rigid intramedullary nailing was performed in 27 patients with a total of 63 segments (57 femora, 6 tibiae). Majority of patients had underlying diagnoses of osteogenesis imperfecta or fibrous dysplasia (including McCune Albright disease). Mean age at surgery was 14 years. Indications for surgery included acute fractures, prophylactic stabilisation, previous nonunion and malunion, deformity correction and lengthening via distraction osteogenesis. Results. All fractures healed. Correction of deformity was successfully achieved in all segments. Delayed union occurred in 4 segments in 1 patient and was successfully treated with nail dynamization. Other complications included prominence, cortical penetrance and loosening of locking screws. One patient who had lengthening performed had nonunion and was managed with exchange nailing and adjunctive measures. Conclusions. Rigid intramedullary nailing is very effective in stabilisation and deformity correction of long bones in adolescent patients with pathological bone disease. The technique has low complication rates. We recommend the use of this technique in paediatric units with experience in managing metabolic bone conditions


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 67 - 67
24 Nov 2023
Gardete-Hartmann S Simon S Frank BJ Sebastian S Loew M Sommer I Hofstaetter J
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Aim. Synovial calprotectin point-of-care test (POC) has shown promising clinical value in diagnosing periprosthetic joint infections (PJIs). However, limited data are available in unclear cases. Moreover, cut-off values for calprotectin lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) need to be adapted. The aim of this study was to evaluate the performance of an upgraded and more sensitive version of a synovial calprotectin LFA along with ELISA immunoassay in patients with septic, aseptic, and unclear cases. Methods. Overall, 206 prospectively collected periprosthetic synovial fluid samples from 169 patients (106f/63m; 38 hip/131 knee) who underwent revision surgeries were retrospectively evaluated for calprotectin concentration. The following groups were analyzed: unexpected negative cultures (UNC; 32/206), unexpected positive cultures (UPC; 28/206), and unclear cases (65/206) with conflicting clinical results. In addition, we added a true aseptic (40/206), and true septic (41/206) control groups according to the international consensus meeting (ICM) 2018 PJI classification. Calprotectin concentration was determined by a rapid quantitative LFA (n=206) (Lyfstone®, Norway), and compared to calprotectin ELISA immunoassay (171/206). For the determination of a new calprotectin cut-off value, analysis of the area under the curve (AUC) followed by Youden's J statistic were performed using the calproctectin values from clear septic and aseptic cases. Sensitivity and specificity for calprotectin were calculated. All statistical analyses were performed using IBM-SPSS® version 25 (Armonk, NY, USA). Results. An absolute calprotectin value of 43 mg/ml, and 40.15 mg/ml was determined to be the optimal cut-off for PJI diagnosis using the new version of the LFA and ELISA, respectively. With this cut-off, the sensitivity and specificity of synovial calprotectin concentration for PJI were 88.1% (95% CI 77.8 to 94.7) and 76.6% (95% CI 61.9 to 87.7) for LFA, and 97.06% (95% CI 89.8 to 99.64) and 93.6% (95% CI 82.5 to 98.66) for ELISA, respectively. Of the evaluated groups, UNC 30/32 (93.8%) vs 26/27 (96.3%), UPC 6/28 (21.4%) vs 4/21 (19%), and unclear samples 45/65 (69.2%) vs 30/56 (53.6%) displayed a high likelihood of infection by using LFA, and ELISA, respectively. Conclusion. The upgraded version of the calprotectin quantitative LFA with a new suggested cut-off for infected samples showed additional clinical value in identifying cases at high risk of infection in unclear PJI revisions. Additionally, calprotectin ELISA immunoassay had a better performance than LFA. Further large sample-size validation studies are warranted


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 17 - 17
1 Feb 2021
Catani F Marcovigi A Zambianchi F
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Introduction. Dislocation is a major cause of Total Hip Arthroplasty (THA) early failure and is highly influenced by surgical approach and component positioning. Robotic assisted arthroplasty has been developed to improve component positioning and therefore reduce post-operative complications. The purpose of this study was to assess dislocation rate in robotic total hip arthroplasty performed with three different surgical approaches. Methods. All patients undergoing Robotic Arm-Assisted THA at three centers between 2014 and 2019 were included for assessment. After exclusion, 1059 patients were considered; an anterior approach was performed in 323 patients (Center 2), lateral approach in 394 patients (Center 1 and Center 2) and posterior approach in 394 patients (Center 1 and Center 3). Episodes of THA dislocation at 6 months of follow up were recorded. Stem anteversion, Cup anteversion, Cup inclination and Combined Anteversion were collected with the use of the integrated navigation system. Cumulative incidence (CI), incidence rate (IR) and risk ratio (RR) were calculated with a confidence interval of 95%. Results. Three cases of dislocation (2 posterior approach, 1 anterior approach) were recorded, with a dislocation rate of 0.28% and an IR of 0.14%. Placement of cup in Lewinnek safe zone rate was 82.2% for posterior approach, 82.0% for lateral approach and 95.4% for anterior approach. Placement in the Combined Version safe zone rate was 98.0% for posterior approach, 73.0% for lateral approach and 47.1% for anterior approach. Despite the difference, dislocation IR was 0.30% for anterior approach, 0.34% for posterior approach and 0% for lateral approach. Conclusion. Robotic assisted technique is associated with low dislocation risk, especially in posterior approach. The Combined version technique appears to be a reliable way to reduce dislocation risk in the posterior lateral approach, but does not appear to be essential for lateral and anterior approaches


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 28 - 28
1 Feb 2012
Kumar V Panagopoulos A Triantafyllopoulos J Fitzgerald S van Niekerk L
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Aim. The aim of this study was to compare the diagnostic accuracy of the Magnetic Resonance Imaging with that of Stress views of the ankle in testing the integrity of the lateral ankle ligaments. Arthroscopic diagnosis was used as the gold standard. Methods. This was a prospective study involving 45 patients who had previous trauma to the ankle and reported symptoms of ankle instability. Our patients were recreational athletes or military patients. These patients had MRI evaluation prior to arthroscopic evaluation and treatment of the ankle. The diagnosis regarding the integrity of the Calcaneofibular ligament (CFL) and the Anterior Talo-fibular ligament (ATFL), as obtained from the MRI was compared against the assessment of integrity from the stress views. These were compared against the assessment made by direct visualisation of the ligaments during arthroscopy. The sensitivity, specificity, negative (NPV) and positive predictive values (PPV) and accuracy were then calculated. Results. The sensitivity and specificity of the MRI and the stress views were poor for diagnosis of ATFL tears. However, the stress views had better sensitivity (93.7%) and specificity (96.5%), for the CFL, as compared with those of the Magnetic Resonance scans (sensitivity 50% and specificity of 86.2%). There was a difference between the diagnostic accuracy of the two methods of investigation with respect to integrity of the CFL but not of that of the ATFL. The PPV and the NPV for the ATFL was comparable using the MRI and the stress radiographs, the stress radiographs had a better predictive values for the calcaneo-fibular ligament, PPV of 93.7% and NPV of 96.5%. Conclusion. The results of this study suggest that routine pre-operative Magnetic Resonance Imaging is not beneficial or cost effective in diagnosing lateral ligament


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 104 - 104
1 Feb 2020
Zarei M Hamlin B Urish K Anderst W
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INTRODUCTION. Controversy exists regarding the ability of unicompartmental knee arthroplasty (UKA) to restore native knee kinematics, with some studies suggesting native kinematics are restored in most or all patients after UKA. 1–3. , while others indicate UKA fails to restore native knee kinematics. 4,5. Previous analysis of UKA articular contact kinematics focused on the replaced compartment. 2,5. , neglecting to assess the effects of the arthroplasty on the contralateral compartment which may provide insight to future pathology such as accelerated degeneration due to overload. 6. or a change in the location of cartilage contact. 7. The purpose of this study was to assess the ability of medial UKA to restore native knee kinematics, contact patterns, and lateral compartment dynamic joint space. We hypothesized that medial UKA restores knee kinematics, compartmental contact patterns, and lateral compartment dynamic joint space. METHODS. Six patients who received fixed-bearing medial UKA consented to participate in this IRB-approved study. All patients (4 M, 2 F; average age 62 ± 6 years) completed pre-surgical (3 weeks before) and post-surgical (7±2 months) testing. Synchronized biplane radiographs were collected at 100 images per second during three repetitions of a chair rise movement (Figure 1). Motion of the femur, tibia, and implants were tracked using an automated volumetric model-based tracking process that matches subject-specific 3D models of the bones and prostheses to the biplane radiographs with sub-millimeter accuracy. 8. Anatomic coordinate systems were created within the femur and tibia. 9. and used to calculate tibiofemoral kinematics. 10. Additional outcome measures included the center of contact in the medial and lateral compartments, and the lateral compartment dynamic joint space (i.e. the distance between subchondral bone surfaces). 11. The results of the three movement trials were averaged for each knee in each test session. All outcome measures were interpolated at 5° increments of knee extension (Figure 2). The average differences between knees at corresponding flexion angles were analyzed using paired t-tests with significance set at p < 0.05. RESULTS. The UKA knee was in 5.3° more varus than the contralateral knee prior to surgery (p=0.005). After surgery, the UKA knee was in 4.9° more valgus than before surgery (p=0.005). The UKA knee was 4.3° more externally rotated than the contralateral knee post-surgery (p=0.05) (Table 1). No significant differences were observed between knees or pre- to post-surgery in lateral compartment dynamic joint space or the center of contact in the medial and lateral tibia compartments (Table 1). DISCUSSION. These results suggest that medial UKA can restore native knee varus without significantly altering lateral compartment joint space or contact location during the chair rise movement. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 120 - 120
1 Jun 2018
Berend M
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Not all degenerative knees need a total knee replacement. Over the last few decades we have shifted our surgical treatment of end-stage osteoarthritis (OA) of the knee to a “compartmental approach” resulting in approximately half of end-stage OA knees receiving a partial knee replacement. Of these an emerging procedure is isolated lateral compartment replacement with the indications being isolated bone-on-bone osteoarthritis or avascular necrosis of the lateral compartment of the knee. Associated significant patellofemoral disease and inflammatory arthritis are contraindications. The purpose of this study is to present the indications, surgical technique, and early outcome of lateral partial knees from our institution. From Aug 2011 until June 2017 we have performed 3,548 knee arthroplasties. Of these 147 were fixed bearing lateral partial knee replacements via a lateral parapatellar approach (4%), 1,481 medial partial knee replacements (42%), and 1,920 total knee replacements (54%). The average age was 66 years old and 76% were female. Average follow-up in the lateral partials was 1.3 years (range 0.5 years to 6 years). Knee Society Scores improved from 41 (pre-op) to 86 points (post-op). Range of motion improved from 6 – 113 degrees (pre-op) to 0 – 123 degrees (post-op). No knees were revised to a TKA. One knee required I&D for traumatic wound dehiscence. This is the largest single center series of lateral partial knee replacements. We have observed this cohort to have more female patients and gain additional range of motion compared to our historic cohorts of TKA's. Longer-term follow-up is needed for determination of implant and unreplaced compartment survivorship. We believe the lateral partial knee replacement to be a viable option for isolated lateral compartment disease in approximately 4% of patients


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 72 - 72
1 Dec 2016
Cobb J
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Lateral meniscal failure and secondary valgus with lateral compartment arthrosis is quite common in the developed world. The varus knee is the common phenotype of the ‘jock’ of both genders, while the valgus knee is a common consequence of lateral meniscal tear, skiing or ‘catwalk’ life. Occurring more commonly in ‘flamingo’ phenotypes, lateral meniscal failure can be disabling, entirely preventing high heels being worn for instance. Indications. Lateral UKA is indicated for most valgus knees, and is substantially safer than TKA. ACL integrity is not essential in older people, as the patello-femoral mechanism is in line with the lateral compartment. Severe valgus with substantial bone loss is not a contraindication, if the deformity is simply angular. As long as there is not marked subluxation, fixed flexion deformity invariably corrects after notch osteophyte removal from femur and tibia. Combinations. Lateral UKA can be combined safely with PFJA: performed through a lateral approach, this is a safe and conservative procedure. ACL integrity is not essential – reconstruction can be undertaken simultaneously, if necessary. Combining lateral UKA with medial UKA is only rarely needed, and sometimes needs ACL reconstruction too. Adding a medial UKA in under 5 years usually results from overcorrection of the valgus. Mid Term Results, at a median of 7 years postop: Between 2005 to 2009, 64 knees in 58 patients had a lateral UKA using a device designed for the lateral compartment. This included 41 females and 17 males with a mean age of 71 years at the time of surgery (range 44–92). Thirty-nine patients underwent surgery on the right knee and 6 underwent bilateral procedures, of which four were performed under a single anesthetic. Primary lateral compartment osteoarthritis was the primary diagnosis in 63 cases with secondary osteoarthritis to a lateral tibial plateau fracture the indication in one patient. At 119 months follow up, the predicted cumulative survival was 0.97. With re-operation as an endpoint, 11% of patients within the study had undergone re-operation with a predicted cumulative survival of 0.81 at 119 months. This compares well with historic fixed bearing series. Preoperative OKS scores were available for 50 knees, scores were available for 63 knees at 9–48 months and 52 knees at 61–119 months post index operation. There was a significant improvement in the OKS between the preoperative scores (median 26 range 9–36) and early postoperative time points of 9–48 months, (median 42 range 23–48) (p<0.001). At the later postoperative time point of 61–119 months the score had been maintained (42 range 10–48). Conclusion. Lateral UKA is a small and safe procedure, with clinical outcomes that are equivalent to a medial UKA and are maintained at a median of 7 years postoperatively


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 72 - 72
1 Apr 2017
Brooks P
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Distal femoral varus osteotomy is a procedure intended to relieve pain, correct valgus deformity, and delay or possibly prevent the progression of lateral compartment osteoarthritis in the knee. It is indicated in patients who are considered too young or are too active to be considered candidates for total knee arthroplasty. It also allows protection of the lateral compartment in cases of meniscal or cartilage allograft. In patients who are a good candidate for total knee replacement, TKR is the procedure of choice. A sloping joint line requires that the correction be performed above the knee. Several methods of distal femoral varus osteotomy have been proposed. These include a medial closing wedge, a lateral opening wedge, and a dome osteotomy. In the author's experience, the medial closing wedge has proven reliable. This technique uses a 90-degree blade plate, and does not require any angle measurements during surgery. Fixation is secure, allowing early motion. Healing proceeds rapidly in the metaphyseal bone, and non-unions have not occurred. The desired final alignment was zero degrees, which was reliably achieved using this method. Medium to long-term results are generally satisfactory. When conversion to total knee replacement is required, standard components may generally be used, and function was not compromised by the prior osteotomy. Distal femoral varus osteotomy is a successful procedure for lateral compartment osteoarthritis in a valgus knee. It is indicated in patients who are too young or active for total knee arthroplasty, and provides an excellent functional and cosmetic result


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 144 - 144
1 Jul 2020
Sepehri A Slobogean G O'Hara N O'Toole RV
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In the polytrauma patient, intraoperative patient positioning is one factor thought to influence pulmonary complications associated with intramedullary (IM) nailing of the femur. With regards to lateral femoral nailing, it is currently unknown as to whether the position of the injured lung contributes to changes in pulmonary function. It has been proposed that, similar to prone positioning in the ICU for acute respiratory distress syndrome management, having the injured lung in a dependent position during lateral femoral nailing would prevent barotrauma from hyperinflation and promote gas exchange in the non-dependent healthy lung. This study aims to assess the association between the position of the injured lung during lateral femoral nailing and pulmonary complications as determined by ICU LOS. This retrospective cohort study was conducted at a single level 1 trauma centre. All patients treated with IM nailing for femur fracture between 2006 and 2014 were screened for inclusion. Only patients who 1) underwent lateral femoral nailing and 2) had a significant chest injury, defined by chest Abbreviated Injury Scale (AIS) of three or greater, were included. Patients with bilateral femur fractures or symmetric bilateral thoracic injuries were excluded. Intraoperative position of the lung injury was described depending on whether the injured lung was down, or in the dependent position, during lateral femoral nailing, versus the healthy lung down. The primary outcome was ICU LOS in all study patients. Secondary analysis was performed on the subgroup of patients who were admitted to ICU prior to femoral nailing. Data analysis assessing for differences in ICU LOS between groups was performed through Wilcoxan testing. One hundred and thirteen femur fractures were included in the study. During lateral femoral nailing, 53 patients had the injured lung down and 60 patients had the healthy lung down. No differences between age, ICU admission rate, injury severity score, chest AIS or head AIS were detected between the groups. There were no detectable differences in the rate of ICU admission between patients with the injured lung down (47.2%) and patients with the healthy lung down (46.7%) (P=0.96). We were unable to detect a difference in average ICU LOS between patients who had the injured lung down (4.9 days, 95% CI 2.8 – 7) compared to patients with the healthy lung down (6 days, 95% CI 3.7 – 8.4) during lateral femoral nailing (P=0.73). When looking only at patients who were admitted to ICU prior to femoral nailing, the LOS was 10.3 days (95% CI 7 – 13.7) in injured lung down patients compared to 12.9 days (9.2 – 16.6) in healthy lung down patients (P= 0.25). In patients with chest AIS greater than three, the position of the injured lung during lateral femoral IM nailing does not appear to affect ICU LOS


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 70 - 70
1 Dec 2016
Brooks P
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Distal femoral varus osteotomy is a procedure intended to relieve pain, correct valgus deformity, and delay or possibly prevent the progression of lateral compartment osteoarthritis in the knee. It is indicated in patients who are considered too young or are too active to be considered candidates for total knee arthroplasty. It also allows protection of the lateral compartment in cases of meniscal or cartilage allograft. In patients who are a good candidate for total knee replacement, TKR is the procedure of choice. A sloping joint line requires that the correction be performed above the knee. Several methods of distal femoral varus osteotomy have been proposed. These include a medial closing wedge, a lateral opening wedge, and a dome osteotomy. In the author's experience, the medial closing wedge has proven reliable. This technique uses a 90-degree blade plate, and does not require any angle measurements during surgery. Fixation is secure, allowing early motion. Healing proceeds rapidly in the metaphyseal bone, and non-unions have not occurred. The desired final alignment was zero degrees, which was reliably achieved using this method. Medium to long-term results are generally satisfactory. When conversion to total knee replacement is required, standard components may generally be used, and function was not compromised by the prior osteotomy. Distal femoral varus osteotomy is a successful procedure for lateral compartment osteoarthritis in a valgus knee. It is indicated in patients who are too young or active for total knee arthroplasty, and provides an excellent functional and cosmetic result


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 17 - 17
1 Jul 2020
Badre A Axford D Banayan S Johnson J King GJ
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The role of anconeus in elbow stability has been a long-standing debate. Anatomical and electromyographic studies have suggested a potential role as a stabilizer. However, to our knowledge, no clinical or biomechanical studies have investigated its role in improving the stability of a lateral collateral ligament (LCL) deficient elbow. Seven cadaveric upper extremities were mounted in an elbow motion simulator in the varus position. An LCL injured model was created by sectioning of the common extensor origin, and the LCL. The anconeus tendon and its aponeurosis were sutured in a Krackow fashion and tensioned to 10N and 20N through a transosseous tunnel at its origin. Varus-valgus angles and ulnohumeral rotations were recorded using an electromagnetic tracking system during simulated active elbow flexion with the forearm pronated and supinated. During active motion, the injured model resulted in a significant increase in varus angulation (5.3°±2.9°, P=.0001 pronation, 3.5°±3.4°, P=.001 supination) and external rotation (ER) (8.6°±5.8°, P=.001 pronation, 7.1°±6.1°, P=.003 supination) of the ulnohumeral articulation compared to the control state (varus angle −2.8°±3.4° pronation, −3.3°±3.2° supination, ER angle 2.1°±5.6° pronation, 1.6°±5.8° supination). Tensioning of the anconeus significantly decreased the varus angulation (−1.2°±4.5°, P=.006 for 10N in pronation, −3.9°±4°, P=.0001 for 20N in pronation, −4.3°±4°, P=.0001 for 10N in supination, −5.3°±4.2°, P=.0001 for 20N in supination) and ER angle (2.6°±4.5°, P=.008 for 10N in pronation, 0.3°±5°, P=.0001 for 20N in pronation, 0.1°±5.3°, P=.0001 for 10N in supination, −0.8°±5.3°, P=.0001 for 20N in supination) of the injured elbow. Comparing anconeus tensioning to the control state, there was no significant difference in varus-valgus angulation except with anconeus tensioning to 20N with the forearm in supination which resulted in less varus angulation (P=1 for 10N in pronation, P=.267 for 20N in pronation, P=.604 for 10N in supination, P=.030 for 20N in supination). Although there were statistically significant differences in ulnohumeral rotation between anconeus tensioning and the control state (except with anconeus tensioning to 10N with the forearm in pronation which was not significantly different), anconeus tensioning resulted in decreased external rotation angle compared to the control state (P=1 for 10N in pronation, P=.020 for 20N in pronation, P=.033 for 10N in supination, P=.001 for 20N in supination). In the highly unstable varus elbow orientation, anconeus tensioning restores the in vitro stability of an LCL deficient elbow during simulated active motion with the forearm in both pronation and supination. Interestingly, there was a significant difference in varus-valgus angulation between 20N anconeus tensioning with the forearm supinated and the control state, with less varus angulation for the anconeus tensioning which suggests that loads less than 20N is sufficient to restore varus stability during active motion with the forearm supinated. Similarly, the significant difference observed in ulnohumeral rotation between anconeus tensioning and the control state suggests that lesser degrees of anconeus tensioning would be sufficient to restore the posterolateral instability of an LCL deficient elbow. These results may have several clinical implications such as a potential role for anconeus strengthening in managing symptomatic lateral elbow instability