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Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 315 - 315
1 Jul 2014
Dhooge Y Wentink N Theelen L van Hemert W Senden R
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Summary. The ankle X-ray has moderate diagnostic power to identify syndesmotic instability, showing large sensitivity ranges between observers. Classification systems and radiographic measurements showed moderate to high interobserver agreement, with extended classifications performing worse. Introduction. There is no consensus regarding the diagnosis and treatment of ankle fractures with respect to syndesmotic injury. The diagnosis of syndesmotic injury is currently based on intraoperative findings. Surgical indication is mainly made by ankle X-ray assessment, by several classification systems and radiographic measurements. Misdiagnosis of the injury results in suboptimal treatment, which may lead to chronic complaints, like instability and osteoarthritis. This study investigates the diagnostic power and interobserver agreement of three classification methods and radiographic measures, currently used to assess X-ankles and to identify syndesmotic injury. Patients and Methods. Twenty patients (43.2 ± 15.3yrs) with an ankle fracture, indicated for surgery, were prospectively included. All patients received a preoperative ankle X-ray, which was assessed by several observers: two orthopaedic surgeons, one trauma surgeon and two radiologists. The ankle X-ray was assessed on syndesmotic injury/stability and presence of fractures (fibula, medial/tertius malleolus). Three classification systems were used: Weber, AO-Müller (short-version n=3 options; extended-version n=27 options), Lauge-Hansen (short-version n=5 options; extended-version n=17 options) and two radiographic measurements were done: tibiofibular overlap (TFO) and ratio medial clearspace/superior clear space (MCS/SCS). All observers were instructed about the assessments before the measurements. During surgery, a proper intraoperative description of the syndesmosis was noted. Agreement (%), Intraclass Correlation Coefficients (ICC) and Kappa were calculated to determine interobserver agreement. Kappa statistic was interpreted according to Landis and Koch. To test the diagnostic power of ankle X-rays to identify syndesmotic instability, sensitivity and specificity were calculated with intraoperative findings serving as golden standard. Results. Six of 20 ankles showed syndesmotic instability intraoperatively. An overall sensitivity of 43% (specificity: 78) was found for X-rays in identifying syndesmotic instability, showing a wide range in sensitivity between observers (17–83%), with radiologists performing better (range 50–83%) than surgeons (range: 17–33%). Overall, substantial to perfect interobserver agreement (range 70–100%) was found for all short classification systems, showing an average kappa ≥0.60. The agreement reduced for more extended classification systems. E.g. observer agreement for the AO-Muller classification with 3, 9 and 27 options was respectively 85% (kappa 0.66), 68% (kappa 0.57) and 55% (kappa 0.51). One observer deviated slightly from others in all classification assessments. Removing this observer resulted in excellent agreement for all classification systems (>90%). Radiographic measurements showed moderate to high interobserver agreement, with TFO performing best (avg. ICC 0.88). Discussion/Conclusion. In ankle fractures, a preoperative X-ray has low sensitivity in detecting syndesmotic instability, showing large sensitivity ranges between observers. Further study is needed to investigate the contribution of classification systems in determining the best treatment method for syndesmotic injury. Ankle X-ray assessment using the three classification systems and radiographic measures was consistent among observers. Disagreement between observers can be attributed to intrinsic differences among the systems (e.g. stepwise classification vs. single assessment). No preference for one specific classification was found, as all showed comparable interobserver agreement. However classification systems with few options are recommended, as the observer agreement reduced with more extending classifications


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 12 - 12
1 Dec 2022
Maggini E Bertoni G Guizzi A Vittone G Manni F Saccomanno M Milano G
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Glenoid and humeral head bone defects have long been recognized as major determinants in recurrent shoulder instability as well as main predictors of outcomes after surgical stabilization. However, a universally accepted method to quantify them is not available yet. The purpose of the present study is to describe a new CT method to quantify bipolar bone defects volume on a virtually generated 3D model and to evaluate its reproducibility. A cross-sectional observational study has been conducted. Forty CT scans of both shoulders were randomly selected from a series of exams previously acquired on patients affected by anterior shoulder instability. Inclusion criterion was unilateral anterior shoulder instability with at least one episode of dislocation. Exclusion criteria were: bilateral shoulder instability; posterior or multidirectional instability, previous fractures and/or surgery to both shoulders; congenital or acquired inflammatory, neurological, or degenerative diseases. For all patients, CT exams of both shoulders were acquired at the same time following a standardized imaging protocol. The CT data sets were analysed on a standard desktop PC using the software 3D Slicer. Computer-based reconstruction of the Hill-Sachs and glenoid bone defect were performed through Boolean subtraction of the affected side from the contralateral one, resulting in a virtually generated bone fragment accurately fitting the defect. The volume of the bone fragments was then calculated. All measurements were conducted by two fellowship-trained orthopaedic shoulder surgeons. Each measurement was performed twice by one observer to assess intra-observer reliability. Inter and intra-observer reliability were calculated. Intraclass Correlation Coefficients (ICC) were calculated using a two-way random effect model and evaluation of absolute agreement. Confidence intervals (CI) were calculated at 95% confidence level for reliability coefficients. Reliability values range from 0 (no agreement) to 1 (maximum agreement). The study included 34 males and 6 females. Mean age (+ SD) of patients was 36.7 + 10.10 years (range: 25 – 73 years). A bipolar bone defect was observed in all cases. Reliability of humeral head bone fragment measurements showed excellent intra-observer agreement (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good interobserver agreement (ICC: 0.89, CI 95%: 0.80 – 0.94). Similarly, glenoid bone loss measurement resulted in excellent intra-observer reliability (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good inter-observer agreement (ICC: 0.84, CI 95%:0.72 – 0.91). In conclusion, matching affected and intact contralateral humeral head and glenoid by reconstruction on a computer-based virtual model allows identification of bipolar bone defects and enables quantitative determination of bone loss


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 29 - 29
1 Dec 2022
Pedrini F Salmaso L Mori F Sassu P Innocenti M
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Open limb fractures are typically due to a high energy trauma. Several recent studied have showed treatment's superiority when a multidisciplinary approach is applied. World Health Organization reports that isolate limb traumas have an incidence rate of 11.5/100.000, causing high costs in terms of hospitalization and patient disability. A lack of experience in soft tissue management in orthopaedics and traumatology seems to be the determining factor in the clinical worsening of complex cases. The therapeutic possibilities offered by microsurgery currently permit simultaneous reconstruction of multiple tissues including vessels and nerves, reducing the rate of amputations, recovery time and preventing postoperative complications. Several scoring systems to assess complex limb traumas exist, among them: NISSSA, MESS, AO and Gustilo Anderson. In 2010, a further scoring system was introduced to focus open fractures of all locations: OTA-OFC. Rather than using a single composite score, the OTA-OFC comprises five components grades (skin, arterial, muscle, bone loss and contamination), each rated from mild to severe. The International Consensus Meeting of 2018 on musculoskeletal infections in orthopaedic surgery identified the OTA-OFC score as an efficient catalogue system with interobserver agreement that is comparable or superior to the Gustilo-Anderson classification. OTA-OFC predicts outcomes such as the need for adjuvant treatments or the likelihood of early amputation. An orthoplastic approach reconstruction must pay adequate attention to bone and soft tissue infections management. Concerning bone management: there is little to no difference in terms of infection rates for Gustilo-Anderson types I–II treated by reamed intramedullary nail, circular external fixator, or unreamed intramedullary nail. In Gustilo-Anderson IIIA-B fractures, circular external fixation appears to provide the lowest infection rates when compared to all other fixation methods. Different technique can be used for the reconstruction of bone and soft tissue defects based on each clinical scenario. Open fracture management with fasciocutaneous or muscle flaps shows comparable outcomes in terms of bone healing, soft tissue coverage, acute infection and chronic osteomyelitis prevention. The type of flap should be tailored based on the type of the defect, bone or soft tissue, location, extension and depth of the defect, size of the osseous gap, fracture type, and orthopaedic implantation. Local flaps should be considered in low energy trauma, when skin and soft tissue is not traumatized. In high energy fractures with bone exposure, muscle flaps may offer a more reliable reconstruction with fewer flap failures and lower reoperation rates. On exposed fractures several studies report precise timing for a proper reconstruction. Hence, timing of soft tissue coverage is a critical for length of in-hospital stay and most of the early postoperative complications and outcomes. Early coverage has been associated with higher union rates and lower complications and infection rates compared to those reconstructed after 5-7 days. Furthermore, early reconstruction improves flap survival and reduces surgical complexity, as microsurgical free flap procedures become more challenging with a delay due to an increased pro-thrombotic environment, tissue edema and the increasingly friable vessels. Only those patients presenting to facilities with an actual dedicated orthoplastic trauma service are likely to receive definitive treatment of a severe open fracture with tissue loss within the established parameters of good practice. We conclude that the surgeon's experience appears to be the decisive element in the orthoplastic approach, although reconstructive algorithms may assist in decisional and planification of surgery


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 141 - 141
1 Jul 2014
Meijer M Boerboom A Stevens M Bulstra S Reininga I
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Summary. The EOS stereography system has been developed for the evaluation of prosthetic alignment. This new low-dose device provides reliable 2D/3D measurements of knee prosthesis alignment. Introduction. Achieving optimal prosthetic alignment during Total Knee Arthroplasty (TKA) is an essential part of the surgical procedure since malpositioning can lead to early loosening of the prosthesis and eventually revision surgery. Conventional weight-bearing radiographs are part of the usual clinical follow-up after both primary TKA and revision TKA (rTKA), to assess alignment in the coronal and sagittal planes. However, proportions and angles may not be correct on radiographs since divergence exists in the vertical and horizontal planes. Furthermore estimating the exact planes by looking at the position of the patella depends on rotation in the hip joint and this may be misinterpreted by the investigator. A computed tomography (CT) scanogram can also be used. However, due to high levels of radiation and costs it is not routinely used. To this end, a new device, the EOS stereography system, has been developed. With this biplanar low-dose X-ray technique, orthogonally made 2D images and 3D reconstructions can be obtained. Advantages of EOS are that images of the leg are obtained on a 1:1 scale with an amount of radiation 800–1000 times lower than CT-scans and 10 times lower than conventional radiographs. Another advantage is that the 3D reconstructions lead to determination of the real coronal and sagittal planes. However, the software for creating 3D reconstructions is developed for the lower limbs without knee prosthesis material. Consequently a reliability study concerning the generation of 2D images and 3D reconstructions of a leg containing a knee prosthesis has not been performed yet. Therefore objective of this study was to investigate interobserver and intraobserver reliability of knee prosthetic alignment measurements after rTKA using EOS. Patients and Methods. Forty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Measured angles were varus/valgus angle in 2D (VV2D) and 3D (VV3D). Intraclass correlation coefficients (ICCs) were used to determine relative reliability and the Bland and Altman method was used to determine absolute reliability. T-tests were used to test potential differences between the two observers, first and second measurement sessions and 2D and 3D measurements. Results. Relative interobserver reliability was excellent for both VV2D and VV3D with ICCs > 0.95, and no significant differences between the two observers. For the absolute reliability of VV2D, a bias of −0.16° (95%CI: −0.31–0.01) existed between both observers. Absolute reliability of VV3D was good. Relative intraobserver reliability was excellent for both VV2D and VV3D with ICCs > 0.97. No significant difference and no bias between the first and second measurements were found. A significant difference existed between the angles measured in 2D and 3D (p=0.01). Discussion / Conclusion. The EOS low-dose stereography system provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between the varus/valgus measurements in 2D and in 3D. Therefore, a validation study is suggested to investigate the difference between the 2D measurements and 3D reconstructions and to find a possible explanation for this difference


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 8 | Pages 1105 - 1109
1 Aug 2006
Kandemir U Allaire RB Jolly JT Debski RE McMahon PJ

Our aim was to determine the most repeatable three-dimensional measurement of glenoid orientation and to compare it between shoulders with intact and torn rotator cuffs. Our null hypothesis was that glenoid orientation in the scapulae of shoulders with a full-thickness tear of the rotator cuff was the same as that in shoulders with an intact rotator cuff. We studied 24 shoulders in cadavers, 12 with an intact rotator cuff and 12 with a full-thickness tear. Two different observers used a three-dimensional digitising system to measure glenoid orientation in the scapular plane (ie glenoid inclination) using six different techniques. Glenoid version was also measured. The overall precision of the measurements revealed an error of less than 0.6°. Intraobserver reliability (correlation coefficients of 0.990 and 0.984 for each observer) and interobserver reliability (correlation coefficient of 0.985) were highest for measurement of glenoid inclination based on the angle obtained from a line connecting the superior and inferior points of the glenoid and that connecting the most superior point of the glenoid and the most superior point on the body of the scapula. There were no differences in glenoid inclination (p = 0.34) or glenoid version (p = 0.12) in scapulae from shoulders with an intact rotator cuff and those with a full-thickness tear. Abnormal glenoid orientation was not present in shoulders with a torn rotator cuff


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 5 | Pages 683 - 690
1 May 2009
Victor J Van Doninck D Labey L Van Glabbeek F Parizel P Bellemans J

The understanding of rotational alignment of the distal femur is essential in total knee replacement to ensure that there is correct placement of the femoral component. Many reference axes have been described, but there is still disagreement about their value and mutual angular relationship. Our aim was to validate a geometrically-defined reference axis against which the surface-derived axes could be compared in the axial plane. A total of 12 cadaver specimens underwent CT after rigid fixation of optical tracking devices to the femur and the tibia. Three-dimensional reconstructions were made to determine the anatomical surface points and geometrical references. The spatial relationships between the femur and tibia in full extension and in 90° of flexion were examined by an optical infrared tracking system. After co-ordinate transformation of the described anatomical points and geometrical references, the projection of the relevant axes in the axial plane of the femur were mathematically achieved. Inter- and intra-observer variability in the three-dimensional CT reconstructions revealed angular errors ranging from 0.16° to 1.15° for all axes except for the trochlear axis which had an interobserver error of 2°. With the knees in full extension, the femoral transverse axis, connecting the centres of the best matching spheres of the femoral condyles, almost coincided with the tibial transverse axis (mean difference −0.8°, . sd. 2.05). At 90° of flexion, this femoral transverse axis was orthogonal to the tibial mechanical axis (mean difference −0.77°, . sd. 4.08). Of all the surface-derived axes, the surgical transepicondylar axis had the closest relationship to the femoral transverse axis after projection on to the axial plane of the femur (mean difference 0.21°, . sd. 1.77). The posterior condylar line was the most consistent axis (range −2.96° to −0.28°, . sd. 0.77) and the trochlear anteroposterior axis the least consistent axis (range −10.62° to +11.67°, . sd. 6.12). The orientation of both the posterior condylar line and the trochlear anteroposterior axis (p = 0.001) showed a trend towards internal rotation with valgus coronal alignment


The Journal of Bone & Joint Surgery British Volume
Vol. 78-B, Issue 5 | Pages 831 - 834
1 Sep 1996
Koot VCM Kesselaer SMMJ Clevers GJ de Hooge P Weits T van der Werken C

We studied the reliability of the Singh classification of trabecular bone structure in the proximal femur as a measure of osteoporosis, using kappa statistics. Radiographs of fractures of the femoral neck or trochanteric region in 80 consecutive patients were assessed by six observers. The interobserver variation was large; only three of 72 radiographs were given the same classification by all six observers and the kappa values ranged from 0.15 to 0.54. The intraobserver variation showed substantial strength of agreement; kappa values ranged from 0.63 to 0.88. In 77 patients dual-energy X-ray absorptiometry was used to measure bone mineral density. The results were compared with those of the Singh classification: we found no correlation


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 128 - 128
1 Jul 2014
Mellema J Doornberg J Quitton T Ring D
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Summary. Biomechanical studies comparing fixation constructs are predictable and do not relate to the significant clinical problems. We believe there is a need for more careful use of resources in the lab and better collaboration with surgeons to enhance clinical relevance. Introduction. It is our impression that many biomechanical studies invest substantial resources studying the obvious: that open reduction and internal fixation with more and larger metal is stronger. Studies that investigate “which construct is the strongest?” are distracted from the more clinically important question of “how strong is strong enough?”. The aim of this study is to show that specific biomechanical questions do not require formal testing. This study tested our hypothesis that the outcome of a subset of peer reviewed biomechanical studies comparing fracture fixation constructs can be predicted based on common sense with great accuracy and good interobserver reliability. Patients & Methods. Between 2000 and 2012, we found 254 peer reviewed biomechanical studies in prestigious orthopaedic journals comparing construct ‘A’ versus construct ‘B’ to evaluate load to failure in order to determine ‘which construct is the strongest?’. Eleven studies comparing fracture fixation constructs were randomly selected from different journals based on our sense that the answer was obvious prior to performing the study. Three-hundred independent observers; including orthopaedic- and general- surgeons affiliated with the Science of Variation Group (. www.scienceofvariation.org. ), predicted the outcome of these biomechanical studies. Observers were presented the original published illustrations of different treatment modalities and were asked to answer one question: “which construct is the strongest?” Sensitivity, specificity and accuracy were calculated according to standardised formulas. The agreement among the observers was calculated by using a multirater kappa, described by Siegel and Castellan. The kappa values were interpreted as proposed by Landis and Koch. Results. Accuracy was the same or greater than 80% for all studies except for study 1. The level of experience had no influence on the accuracy of predicting outcomes. Sensitivity averaged 84%, ranging from 60% (for study 1) to 99% (for study 7), specificity 86%, ranging from 60% (for study 1) to 99% (for study 7), and accuracy averaged 86% from 60% (for study 1) to 99% (for study 7). The overall categorical rating of inter-observer reliability according to Landis and Koch was moderate (κ = 0,53; SE = 0.01), ranging from κ = 0,03 (SE = 0.01) to κ = 0,95 (SE = 0.01). Analyses of SOVG subgroups identified excellent agreement among Canadian surgeons. Moderate and substantial agreement were found in most of other subgroups: ranging from first year medical students to specialists 20 years or more in practice; and specialists who practice in Australia, Europe and United States. Study 5 was easiest to predict based on common sense (Accuracy 97%, inter-observer reliability 0,88). Study 1 was predicted with least accuracy 61% and the lowest kappa value 0,04. Conclusions. The outcomes of biomechanical studies comparing fracture reduction and fixation constructs are highly predictable with good inter-observer reliability


Bone & Joint 360
Vol. 9, Issue 2 | Pages 46 - 48
1 Apr 2020
Evans JT Whitehouse MR


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 7 | Pages 972 - 975
1 Jul 2006
Spencer JMF Day RE Sloan KE Beaver RJ

Our aim was to assess the intra- and inter-observer reliability in the establishment of the anterior pelvic plane used in imageless computer-assisted navigation. From this we determined the subsequent effects on version and inclination of the acetabular component.

A cadaver model was developed with a specifically-designed rod which held the component tracker at a fixed orientation to the pelvis, leaving the anterior pelvic plane as the only variable. Eight surgeons determined the anterior pelvic plane by palpating and registering the bony landmarks as reference points. The exact anterior pelvic plane was then established by using anatomically-placed bone screws as reference points.

The difference between the surgeons was found to be highly significant (p < 0.001). The variation was significantly larger for anteversion (sd 9.6°) than for inclination (sd 6.3°). The present method for registering pelvic landmarks shows significant inaccuracy, which highlights the need for improved methods of registration before this technique is considered to be safe.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 4 | Pages 520 - 526
1 Apr 2008
Yau WP Leung A Liu KG Yan CH Wong LS Chiu KY

We have investigated the errors in the identification of the transepicondylar axis and the anteroposterior axis between a minimally-invasive and a conventional approach in four fresh-frozen cadaver knees. The errors in aligning the femoral prosthesis were compared with the reference transepicondylar axis as established by CT.

The error in the identification of the transepicondylar axis was significantly higher in the minimal approach (4.5° of internal rotation, sd 4) than in the conventional approach (3° of internal rotation, sd 4; p < 0.001). The errors in identifying the anteroposterior axis in the two approaches were 0° (sd 5) and 1.8° (sd 5) of internal rotation, respectively (p < 0.001).


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 5 | Pages 688 - 691
1 May 2006
van Huyssteen AL Hendrix MRG Barnett AJ Wakeley CJ Eldridge JDJ

Trochlear dysplasia is an important anatomical abnormality in symptomatic patellar instability. Our study assessed the mismatch between the bony and cartilaginous morphology in patients with a dysplastic trochlea compared with a control group.

MRI scans of 25 knees in 23 patients with trochlear dysplasia and in 11 patients in a randomly selected control group were reviewed retrospectively in order to assess the morphology of the cartilaginous and bony trochlea. Inter- and intra-observer error was assessed.

In the dysplastic group there were 15 women and eight men with a mean age of 20.4 years (14 to 30). The mean bony sulcus angle was 167.9° (141° to 203°), whereas the mean cartilaginous sulcus angle was 186.5° (152° to 214°; p < 0.001). In 74 of 75 axial images (98.7%) the cartilaginous contour was different from the osseous contour on subjective assessment, the cartilage exacerbated the abnormality.

Our study shows that the morphology of the cartilaginous trochlea differs markedly from that of the underlying bony trochlea in patients with trochlear dysplasia. MRI is necessary in order to demonstrate the pathology and to facilitate surgical planning.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 6 | Pages 894 - 899
1 Jun 2010
Khattak MJ Ahmad T Rehman R Umer M Hasan SH Ahmed M

The nervous system is known to be involved in inflammation and repair. We aimed to determine the effect of physical activity on the healing of a muscle injury and to examine the pattern of innervation. Using a drop-ball technique, a contusion was produced in the gastrocnemius in 20 rats. In ten the limb was immobilised in a plaster cast and the remaining ten had mobilisation on a running wheel. The muscle and the corresponding dorsal-root ganglia were studied by histological and immunohistochemical methods.

In the mobilisation group, there was a significant reduction in lymphocytes (p = 0.016), macrophages (p = 0.008) and myotubules (p = 0.008) between three and 21 days. The formation of myotubules and the density of nerve fibres was significantly higher (both p = 0.016) compared with those in the immobilisation group at three days, while the density of CGRP-positive fibres was significantly lower (p = 0.016) after 21 days.

Mobilisation after contusional injury to the muscle resulted in early and increased formation of myotubules, early nerve regeneration and progressive reduction in inflammation, suggesting that it promoted a better healing response.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 4 | Pages 557 - 560
1 Apr 2007
Davis ET Gallie P Macgroarty K Waddell JP Schemitsch E

A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°.

The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig.

Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 7 | Pages 958 - 965
1 Jul 2008
Leong JJH Leff DR Das A Aggarwal R Reilly P Atkinson HDE Emery RJ Darzi AW

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device.

The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (α = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment.

This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 5 | Pages 741 - 744
1 May 2005
Beaulé PE Krismer M Mayrhofer P Wanner S Le Duff M Mattesich M Stoeckl B Amstutz HC Biedermann R

Studies on the migration of an implant may be the only way of monitoring the early performance of metal-on-metal prostheses. The Ein Bild Roentgen Analyse - femoral component analysis (EBRA-FCA) method was adapted to measure migration of the femoral component in a metal-on-metal surface arthroplasty of the hip using standard antero-posterior radiographs. In order to determine the accuracy and precision of this method a prosthesis was implanted into cadaver bones. Eleven series of radiographs were used to perform a zero-migration study. After adjustment of the femoral component to simulate migration of 3 mm the radiographs were repeated. All were measured independently by three different observers.

The accuracy of the method was found to be ± 1.6 mm for the x-direction and ± 2 mm for the y-direction (95% percentile). The method was validated using 28 hips with a minimum follow-up of 3.5 years after arthroplasty. Seventeen were sound, but 11 had failed because of loosening of the femoral component. The normal (control) group had a different pattern of migration compared with that of the loose group. At 29.2 months, the control group showed a mean migration of 1.62 mm and 1.05 mm compared with 4.39 mm and 4.05 mm in the failed group, for the centre of the head and the tip of the stem, respectively (p = 0.001). In the failed group, the mean time to migration greater than 2 mm was earlier than the onset of clinical symptoms or radiological evidence of failure, 19.1 versus 32.2 months (p = 0.001) and 24.8 months (p = 0.012), respectively.

EBRA-FCA is a reliable and valid tool for measuring migration of the femoral component after surface arthroplasty and can be used to predict early failure of the implant. It may be of value in determining the long-term performance of surface arthroplasty.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 1 | Pages 114 - 121
1 Jan 2008
Pendegrass CJ Gordon D Middleton CA Sun SNM Blunn GW

Conventional amputation prostheses rely on the attachment of the socket to the stump, which may lead to soft-tissue complications. Intraosseous transcutaneous amputation prostheses (ITAPs) allow direct loading of the skeleton, but their success is limited by infection resulting from breaching of the skin at the interface with the implant. Keratinocytes provide the skin’s primary barrier function, while hemidesmosomes mediate their attachment to natural ITAP analogues. Keratinocytes must attach directly to the surface of the implant. We have assessed the proliferation, morphology and attachment of keratinocytes to four titaniumalloy surfaces in order to determine the optimal topography in vitro. We used immunolocalisation of adhesion complex components, scanning electron microscopy and transmission electron microscopy to assess cell parameters.

We have shown that the proliferation, morphology and attachment of keratinocytes are affected by the surface topography of the biomaterials used to support their growth. Smoother surfaces improved adhesion. We postulate that a smooth topography at the point of epithelium-ITAP contact could increase attachment in vivo, producing an effective barrier of infection.