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Hirschmann M.T.,Kantonsspital Bruderholz | Wagner C.R.,OrthoImagingSolutions Ltd. | Rasch H.,Institute for Radiology and Nuclear Medicine | Henckel J.,Imperial College London
BMC Medical Imaging | Year: 2012

Background: SPECT/CT combines high resolution anatomical 3D computerized tomography (CT) and single photon emission computerized tomography (SPECT) as functional imaging, which provides 3D information about biological processes into a single imaging modality. The clinical utility of SPECT/CT imaging has been recognized in a variety of medical fields and most recently in orthopaedics; however, clinical adoption has been limited due to shortcomings of analytical tools available. Specifically, SPECT analyses are mainly qualitative due to variation in overall metabolic uptake among patients. Furthermore, most analyses are done in 2D, although rich 3D data are available. Consequently, it is difficult to quantitatively compare the position, size, and intensity of SPECT uptake regions among patients, and therefore difficult to draw meaningful clinical conclusions.Methods: We propose a method for normalizing orthopaedic SPECT/CT data that enables standardised 3D volumetric quantitative measurements and comparison among patients. Our method is based on 3D localisation using clinically relevant anatomical landmarks and frames of reference, along with intensity value normalisation using clinically relevant reference regions. Using the normalised data, we describe a thresholding technique to distinguish clinically relevant hot spots from background activity.Results: Using an exemplar comparison of two patients, we demonstrate how the normalised, 3D-rendered data can provide a richer source of clinical information and allow quantitative comparison of SPECT/CT measurements across patients. Specifically, we demonstrate how non-normalized SPECT/CT analysis can lead to different clinical conclusions than the normalized SPECT/CT analysis, and that normalized quantitative analysis can be a more accurate indicator of pathology.Conclusions: Conventional orthopaedic frames of reference, 3D volumetric data analysis and thresholding are used to distinguish clinically relevant hot spots from background activity. Our goal is to facilitate a standardised approach to quantitative data collection and comparison of clinical studies using SPECT/CT, enabling more widespread clinical use of this powerful imaging tool. © 2012 Hirschmann et al; licensee BioMed Central Ltd.


Gerhard P.,Kantonsspital Bruderholz | Bolt R.,Institute of Radiology and Nuclear Medicine | Duck K.,Center Hospitalier Of Luxembourg | Mayer R.,Praxisklinik2000 | And 2 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2013

Purpose: The primary purpose of our study was to analyse the long-term outcome of patients treated for anterior cruciate ligament (ACL) tears by anatomical single-bundle ACL reconstruction with patellar tendon autograft. The secondary purpose was to identify predictive factors for good outcome and occurrence of osteoarthritis. Methods: Sixty-three patients (m:f = 54:9; mean age at surgery, 27 ± 7 years) treated by ACL reconstruction were evaluated with a mean follow-up of 16 ± 1 years using IKDC2000, the SF36, Lysholm and Tegner score, Knee Society score, visual analogue scale for pain and satisfaction and KOOS. The femoral tunnel position was evaluated according to Sommer. It was also assessed in percentage of the Blumensaat line and the tibial tunnel position in percentage of the total anterior-posterior plateau length. The extent of osteoarthritis was graded according to the Kellgren-Lawrence score. Results: The total IKDC2000 was normal in 20 (32 %), nearly normal in 29 (46 %), abnormal in 12 (19 %) and severely abnormal in 3 (5 %) of patients. The mean total SF-36 was 89 ± 13, the Lysholm score 95 ± 12, the Knee Society score 191 ± 16 and the total KOOS 84 ± 19. The Tegner score decreased from pre-injury 7(4-10) to 6 (2-10) at follow-up. The Kellgren-Lawrence score was normal in 17 (27 %), suspected osteoarthritis in 25 (40 %), minimal osteoarthritis in 5 (8 %), moderate osteoarthritis in 9 (14 %) and severe osteoarthritis in 3 patients (5 %). The femoral tunnel was in zone A in 43 patients (68 %), in zone B in 16 (25 %) and in zone C in 4 patients (7 %). The femoral tunnel position in percentage of the Blumensaat line was 49 ± 3 (range, 44-57), and the tibial tunnel position in percentage of the total anterior-posterior plateau length was 32 ± 6 (range, 21-46). Patients with meniscal lesion at the time of ACL tear showed significantly less favourable outcomes than those without. Conclusions: Patients treated by the proposed ACL reconstruction technique showed on average good to excellent long-term results. A meniscal lesion at the time of ACL tear was highly predictive for less favourable outcome. Level of evidence: IV. © 2012 Springer-Verlag.


Hirschmann M.T.,Kantonsspital Bruderholz | Keller L.,Kantonsspital Bruderholz | Hirschmann A.,Balgrist | Schenk L.,Kantonsspital Bruderholz | And 5 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2013

Purpose: The purpose of the study was to evaluate the clinical and radiological outcomes after medial/lateral collagen meniscus substitution (CMI) at 12 months postoperatively. Methods: Sixty-seven patients (m:f = 47:20, mean age 36 ± 10 years) underwent arthroscopic CMI after previous subtotal medial (n = 55) or lateral meniscectomy (n = 12) due to persistent joint line pain (n = 25) or to prophylactic reasons (n = 42). Clinical follow-up consisted of IKDC score, Tegner score, Lysholm score, and visual analog scale for pain and satisfaction (preinjury, preoperatively, and 12 months postoperatively; follow-up rate 90 %). MRI scans were analyzed according to the Genovese criteria. Results: Nineteen patients (29 %) showed a normal (A), 35 nearly normal (B), 5 abnormal (C), and 1 patient severely abnormal total IKDC score (D). The median Tegner preinjury score was 7 (range 2-10) and at follow-up 6 (range 2-10). The mean Lysholm score before surgery was 68 ± 20 and 93 ± 9 at follow-up. Preoperatively, the mean VAS pain was 4. 4 ± 3. 1 and 2. 0 ± 1. 0 at follow-up. Clinical failure of the CMI occurred in 3 patients (n = 1 infection, n = 1 failure of the implant, n = 1 chronic synovitis). On MRI, the CMI was completely resorbed in 3 patients (5 %), partially resorbed in 55 (92 %), and entirely preserved in 3 (5 %) patients. In 5 patients (8 %) the CMI was isointense, in 54 (90 %) slightly and 1 (2 %) highly hyperintense. 43 (72 %) patients showed an extrusion of the CMI implant of more than 3 mm. Conclusions: Significant pain relief and functional improvement throughout all scores at 1 year was noted. The CMI undergoes significant remodeling, degradation, resorption, and extrusion in most of the patients. No difference in outcomes between the medial and lateral CMI was observed. Level of evidence: Prospective therapeutic study, Level IV. © 2012 Springer-Verlag Berlin Heidelberg.


Hirschmann M.T.,Kantonsspital Bruderholz | Fallegger B.,Kantonsspital Bruderholz | Amsler F.,Amsler Consulting | Regazzoni P.,University of Basel | Gross T.,University of Basel
Journal of Orthopaedic Trauma | Year: 2011

OBJECTIVES:: The aim of this study was to investigate the subjective and objective longer-term outcomes after fracture fixation with the Proximal Humerus InterLocking OSteosynthesis (PHILOS) plate. DESIGN:: Minimum 4-year follow-up of a primary prospective cohort study. SETTING:: Single university trauma center. PATIENTS/PARTICIPANTS:: Sixty-four consecutively collected patients fulfilled the study criteria. Seven patients (11%) were lost to follow-up, resulting in 57 patients (65 ± 14 years). INTERVENTION:: Open reduction and internal fixation with the PHILOS® plate. MAIN OUTCOME MEASUREMENTS:: Standardized follow-up including functional outcome instruments (eg, Constant Murley score, Disabilities of the Arm, Shoulder and Hand), rate of complications, and secondary surgeries at 6, 12, and no less than 48 months (uni- and multivariate analysis; P < 0.05). RESULTS:: At the 4- to 6-year follow-up (median 5 years postinjury), patients on average achieved an 87% range of motion of the injured compared with the uninjured shoulder (eg, 133° ± 40° versus 152° ± 26° abduction). Objective and subjective outcome improved significantly during the overall follow-up, most of all in reoperated and younger patients (65 years and younger) and within the first postinjury year. We observed an overall reoperation rate of 29% and 10 patients (17.5%) demonstrated an insufficient result resulting from pain (greater than 3 visual analog scale) or restricted abduction (less than 90°) at longer-term follow-up. First, the need for revision surgery and, second, increasing age were found to be the most predictive factors for unsatisfactory results. CONCLUSIONS:: Fracture fixation with the PHILOS showed good to excellent longer-term results in three fourths of patients with outcome partially still improving after the first postoperative year. Copyright © 2011 by Lippincott Williams & Wilkins.


Hirschmann M.T.,Kantonsspital Bruderholz | Wind B.,Kantonsspital Bruderholz | Amsler F.,Amsler Consulting | Gross T.,University of Basel
Clinical Orthopaedics and Related Research | Year: 2010

Reports using the Constant-Murley score often lack details regarding how strength measurement was performed, which may have an important impact on the results obtained. A description of the measurement is especially important when patients are unable to adopt the prescribed position of 90° shoulder abduction, leading to invalid or highly discrepant scores. We investigated the influence of shoulder abduction and torso position on strength measurement with special emphasis on intraobserver reliability. Thirty-three healthy volunteers were examined using a handheld dynamometer (Isobex®) in 30°, 60°, and 90° abduction with or without stabilization of the torso. A linear correlation between strength measurements in different degrees of abduction was observed, with values at 90° abduction on average 15% lower than at 60° and 45% lower than at 30°. In multivariate analysis, gender and weight had a substantial impact on the strength of individual measurement positions. Intraobserver reliability was related to arm and torso position (intraclass correlation coefficients, 0.71-0.93) and was highest for 90° abduction without torso stabilization. These findings emphasize the importance of standardized torso and arm positions ensuring high reliability when performing the strength measurement of the Constant-Murley score. © 2009 The Association of Bone and Joint Surgeons®.


Hirschmann M.T.,Kantonsspital Bruderholz | Mathis D.,Kantonsspital Bruderholz | Rasch H.,Institute of Radiology and Nuclear Medicine | Amsler F.,Amsler Consulting | And 2 more authors.
International Orthopaedics | Year: 2013

Purpose: SPECT/CT is a hybrid imaging modality, which combines a 3D scintigraphy (SPECT) and a conventional computerised tomography (CT). SPECT/CT allows accurate anatomical localisation of metabolic tracer activity. It allows the correlation of surgical factors such as tunnel position and orientation with mechanical alignment, clinical outcome and biological factors. The purpose of this study was to investigate whether the SPECT/CT tracer uptake (intensity and distribution) correlates with the stability and laxity of the knee joint and the position and orientation of the tibial and femoral tunnels in patients after anterior cruciate ligament (ACL) reconstruction. Methods: A consecutive series of knees (n = 66), with symptoms of pain and/or instability after ACL reconstruction were prospectively evaluated using clinical examination and 99mTc-HDP-SPECT/CT. Clinical laxity testing was performed using the Rolimeter (Ormed, Freiburg, Germany) including Lachman testing (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), anterior drawer test (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), pivot shift test (positive versus negative) and patient-based subjective instability (yes versus no). For analysis of SPECT/CT tracer uptake a previously validated SPECT/CT localisation scheme consisting of 17 tibial, nine femoral and four patellar regions on standardised axial, coronal, and sagittal slices was used. The tracer activity on SPECT/CT was localised and recorded using a 3D volumetric and quantitative analysis software. Mean, standard deviation, minimum and maximum of grading for each area of the localisation scheme were recorded. The position and orientation of the tibial and femoral tunnel was assessed using a previously published method on 3D-CT. Results: Correlation of instability, pivot shift as well as clinical laxity testing with 99mTc-HDP-SPECT/CT tracer uptake intensity and distribution showed no significant correlation. 99mTc-HDP-SPECT/CT tracer uptake correlated significantly with the position and orientation of the ACL graft. A more horizontal femoral graft position showed significantly increased tracer uptake within the superior and posterior femoral regions. A more posteriorly-placed femoral insertion site showed significantly more tracer uptake within the femoral and tibial tunnel regions. A more vertical or a less medial tibial tunnel orientation showed significant increased uptake within the tibial and femoral tunnel regions. A more anterior tibial tunnel position showed significantly more tracer uptake in the femoral and tibial tunnel regions as well as the entire tibiofemoral joint. Conclusions: SPECT/CT tracer uptake intensity and distribution showed a significant correlation with the femoral and tibial tunnel position and orientation in patients with symptomatic knees after ACL reconstruction. No correlation was found with stability or clinical laxity. SPECT/CT tracer uptake distribution has the potential to give us important information on joint homeostasis and remodelling after ACL reconstruction. It might help to predict ACL graft failure and improve our surgical ACL reconstruction technique in finding the optimal tunnel and graft position and orientation. © 2012 Springer-Verlag Berlin Heidelberg.


Bircher A.,University of Basel | Friederich N.F.,Kantonsspital Bruderholz | Seelig W.,Hirslanden Klinik Birshof | Scherer K.,University of Basel
Contact Dermatitis | Year: 2012

Background. Orthopaedic implants and osteosynthesis materials are increasingly being used. Complications include mainly physical-mechanical problems and infections. Uncommonly, an allergic reaction towards an alloy metal or a bone cement component has been implicated. Potential bone cement allergens include acrylates, benzoyl peroxide, N,N-dimethyl-p-toluidine, and gentamicin. Typical symptoms are pain, swelling, inflammatory skin reactions, implant loosening, and fistula formation. Objectives. To report on 5 patients with complications from a knee or a shoulder joint implant in whom a relevant sensitization to benzoyl peroxide was shown. Methods. Patch tests were performed with the European baseline series, an extended metal series, and a bone cement series. Patch tests with benzoyl peroxide were performed twice in all patients. A bone cement-free replacement was chosen in sensitized patients. Results. In 4 patients sensitized to benzoyl peroxide, a bone cement-free replacement resulted in a considerable decrease or disappearance of pain and swelling, and complete clearing of cutaneous symptoms. Conclusions. Components of bone cement, such as benzoyl peroxide, may rarely cause allergic complications. However, because of the irritant potential of these substances, careful performance, reading and interpretation of the patch tests is required. © 2011 John Wiley & Sons A/S.


Friedrich L.,Kantonsspital Bruderholz | Afifi F.K.,Kantonsspital Bruderholz | Skarvan J.,Kantonsspital Bruderholz | Friederich N.F.,Kantonsspital Bruderholz | Hirschmann M.T.,Kantonsspital Bruderholz
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2012

A case of an 18-year-old gardener who sustained an anterior-superior dislocation of the sternoclavicular joint while playing handball and falling on his right shoulder is presented. Non-surgical treatment failed, and the patient could willingly dislocate the right clavicle while abduction and external rotation of the arm. This painful condition was finally treated with surgical reconstruction of the sternoclavicular joint using gracilis tendon autograft and repair of the discus. Level of evidence Therapeutic study, case report and technical note, Level IV. © 2011 Springer-Verlag.


Hirschmann M.T.,Kantonsspital Bruderholz | Konala P.,Kantonsspital Bruderholz | Konala P.,Imperial College London | Amsler F.,Kantonsspital Bruderholz | And 5 more authors.
Journal of Bone and Joint Surgery - Series B | Year: 2011

We studied the intra- and interobserver reliability of measurements of the position of the components after total knee replacement (TKR) using a combination of radiographs and axial two-dimensional (2D) and three-dimensional (3D) reconstructed CT images to identify which method is best for this purpose. A total of 30 knees after primary TKR were assessed by two independent observers (an orthopaedic surgeon and a radiologist) using radiographs and CT scans. Plain radiographs were highly reliable at measuring the tibial slope, but showed wide variability for all other measurements; 2D-CT also showed wide variability. 3D-CT was highly reliable, even when measuring rotation of the femoral components, and significantly better than 2D-CT. Interobserver variability in the measurements on radiographs were good (intraclass correlation coefficient (ICC) 0.65 to 0.82), but rotational measurements on 2D-CT were poor (ICC 0.29). On 3D-CT they were near perfect (ICC 0.89 to 0.99), and significantly more reliable than 2D-CT (p < 0.001). 3D-reconstructed images are sufficiently reliable to enable reporting of the position and orientation of the components. Rotational measurements in particular should be performed on 3D-reconstructed CT images. When faced with a poorly functioning TKR with concerns over component positioning, we recommend 3D-CT as the investigation of choice. ©2011 British Editorial Society of Bone and Joint Surgery.


Arnold M.P.,Kantonsspital Bruderholz | Friederich N.F.,Kantonsspital Bruderholz | Muller W.,Kantonsspital Bruderholz | Hirschmann M.T.,Kantonsspital Bruderholz
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2013

The single-incision anterior cruciate ligament (ACL) reconstruction evidently has its shortcomings. In an attempt to improve the biomechanical but also the biological state of the knees after an ACL-reconstruction, double, even triple-bundle reconstructions have been popularised recently. As a positive side effect, details concerning ACL-insertion anatomy were brought back into the focus. In our opinion it would be more straight forward and logical to replace the non-anatomical single-incision technique with a more anatomic single-bundle ACL-reconstruction technique. © 2012 Springer-Verlag.

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