A novel standardized algorithm for evaluating patients with painful total knee arthroplasty using combined single photon emission tomography and conventional computerized tomography
11 Feb 2010-Knee Surgery, Sports Traumatology, Arthroscopy (Springer-Verlag)-Vol. 18, Iss: 7, pp 939-944
TL;DR: The SPECT/CT algorithm presented is both reliable and useful in the management of patients with painful TKA and combines biomechanical and metabolic data (tracer localization) providing an extra dimension to the understanding of this difficult condition.
Abstract: SPECT/CT is a promising diagnostic modality in patients with painful total knee arthroplasty (TKA). The purpose of this study is to introduce a novel standardized SPECT/CT algorithm and evaluate its clinical application and reliability. A novel SPECT/CT localization scheme consisting of 9 tibial, 9 femoral and 4 patellar regions on standardized axial, coronal and sagittal slices is proposed. It was piloted in 18 consecutive patients with post TKA pain. The tracer activity on SPECT/CT was recorded using a color-coded scale (0-10). The inter- and intra-observer reliability was assessed for localization and tracer activity. The prosthetic component position was assessed in the CT images after 3D reconstruction using standardized frames of reference. The median inter- and intra-observer differences and ranges of the measured angles were calculated along with the ICC values for inter- and intra-observer reliability. The localization scheme showed very high inter- and intra-observer reliabilities for all regions. The measurement of component position was highly reliable in all cases with sufficient visibility of anatomical landmarks. The median inter-observer difference between alignment measurements for tibial and femoral components was less than 3 degrees (range 0 degrees -6 degrees ). The median intra-observer variability for these was less than 2 degrees (range 0 degrees -5 degrees ). The SPECT/CT algorithm presented is both reliable and useful in the management of patients with painful TKA. It combines biomechanical and metabolic data (tracer localization) providing an extra dimension to the understanding of this difficult condition. The clinical value of SPECT/CT in patients with unexplained pain following TKA should be further investigated.
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TL;DR: 3D-reconstructed images are sufficiently reliable to enable reporting of the position and orientation of the components in a poorly functioning TKR with concerns over component positioning, and are recommend 3D-CT as the investigation of choice.
Abstract: 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.
169 citations
TL;DR: Depression, anxiety, a tendency to somatize and psychological distress were identified as significant predictors for poorer clinical outcomes before and/or after TKA.
Abstract: Patient-based and psychological factors do influence outcome in patients undergoing total knee arthroplasty (TKA). The purpose was to investigate if preoperative psychological factors influence the subjective and objective outcomes 6 weeks, 4 months and 1 year after TKA. Our hypothesis was that there is a significant influence of psychological factors on clinical outcome scores before and after TKA. A prospective, longitudinal, single-cohort study investigating the correlation of depression, control beliefs, anxiety and a variety of other psychological factors with outcomes of patients undergoing TKA was performed. A total of 104 consecutive patients were investigated preoperatively using the Beck`s depression inventory, the State-Trait Anxiety Index, the questionnaire for assessment of control beliefs and the SCL-90R inventory. The Knee Society Clinical Rating System (KSS) and the WOMAC were used. Analysis of TKA position was performed on radiographs according to Ewald et al. Correlation of psychological variables with outcomes was performed (p < .05). Self-efficacy did not influence clinical scores. More depressed patients showed higher pre- and postoperative WOMAC scores, but no difference in amelioration. KSS scores were not influenced. Patients with higher State and Trait Anxiety Indexes had higher WOMAC and lower KSS scores before and after the operation, but most significant correlations were <0.3. Several SCL-90 dimensions had significant correlations with pre- and postoperative clinical scores, but not with their amelioration. The SCL-90 subscore for somatization and the overall SCL-90 significantly correlated with the WOMAC, KSS before and after TKA. Depression, anxiety, a tendency to somatize and psychological distress were identified as significant predictors for poorer clinical outcomes before and/or after TKA. Standardized preoperative screening and subsequent treatment should become part of the preoperative work-up in orthopaedic practice. Prognostic prospective, Level I.
145 citations
Cites background from "A novel standardized algorithm for ..."
...Although total knee arthroplasty (TKA) is considered to be a very successful treatment for end-stage osteoarthritis, a considerable number of patients after TKA continue to complain about persistent or recurrent pain and express dissatisfaction [9, 12, 17, 19, 33]....
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...Most common intraarticular causes are aseptic loosening, malposition, infection, instability and extensor mechanism problems such as unresurfaced patella, under- or oversizing of the patella button or patellar maltracking [1, 14, 17, 19, 30]....
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TL;DR: SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patientswith patellofemoral problems and malpositioned or loose TKA.
Abstract: The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). Twenty-three painful knees in patients following primary TKA were assessed using Tc-99m-HDP-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10) and its anatomical distribution was mapped using a validated localization scheme. Univariate analysis (Wilcoxon-Mann-Whitney, Spearmean`s-rho test, p < 0.05) was performed to identify any correlations between component position, tracer uptake and diagnosis. SPECT/CT imaging changed the suspected diagnosis and the proposed treatment in 19/23 (83%) knees. Progression of patellofemoral OA (n = 11), loosening of the tibial (n = 3) and loosening of the femoral component (n = 2) were identified as the leading causes of pain after TKA. Patients with externally rotated tibial trays showed higher tracer uptake in the medial patellar facet (p = 0.049) and in the femur (p = 0.051). Patients with knee pain due to patellofemoral OA showed significantly higher tracer uptake in the patella than others (p < 0.001). SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patients with patellofemoral problems and malpositioned or loose TKA.
101 citations
TL;DR: A practical 10-step diagnostic algorithm is described for failure analysis and it is shown that a sufficient failure analysis is possible in almost all patients with painful TKA.
Abstract: Pain after total knee arthroplasty (TKA) represents a common observation in about 20% of the patients after surgery. Some of these painful knees require early revision surgery within 5 years. Obvious causes of failure might be identified with clinical examinations and standard radiographs only, whereas the unexplained painful TKA still remains a challenge for the surgeon. It is generally accepted that a clear understanding of the failure mechanism in each case is required prior considering revision surgery. A practical 10-step diagnostic algorithm is described for failure analysis in more detail. The evaluation of a painful TKA includes an extended history, analysis of the type of pain, psychological exploration, thorough clinical examination including spine, hip and ankle, laboratory tests, joint aspiration and test infiltration, radiographic analysis and special imaging techniques. It is also important to enquire about the length and type of conservative therapy. Using this diagnostic algorithm, a sufficient failure analysis is possible in almost all patients with painful TKA.
95 citations
Cites background from "A novel standardized algorithm for ..."
...These special bone marrow images are another puzzle piece for differential diagnosis, but should not be performed as a routine [22]....
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TL;DR: There is renewed interest in bone scintigraphy, performed as a SPECT/CT procedure, for detecting joint instability, mechanical loosening and component malpositioning, and the availability of fluorine-18 fluoride PET suggests that the diagnostic paradigm may be shifting again.
Abstract: Soon after the introduction of the modern prosthetic joint, it was recognized that radionuclide imaging provides useful information about these devices. The bone scan was used extensively to identify causes of prosthetic joint failure. It became apparent, however, that although sensitive, regardless of how the images were analyzed or how it was performed, the test was not specific and could not distinguish among the causes of prosthetic failure. Advances in anatomic imaging, notably cross sectional modalities, have facilitated the diagnosis of many, if not most, causes of prosthetic failure, with the important exception of infection. This has led to a shift in the diagnostic paradigm, in which nuclear medicine investigations increasingly have focused on diagnosing infection. The recognition that bone scintigraphy could not reliably diagnose infection led to the development of combined studies, first bone/gallium and subsequently leukocyte/bone and leukocyte/marrow imaging. Labeled leukocyte imaging, combined with bone marrow imaging is the most accurate (about 90%) imaging test for diagnosing joint arthroplasty infection. Its value not withstanding, there are significant disadvantages to this test. In-vivo techniques for labeling leukocytes, using antigranulocyte antibodies have been explored, but have their own limitations and the results have been inconsistent. Fluorodeoxyglucose (FDG)-positron emission tomography (FDG-PET) has been extensively investigated for more than a decade but its role in diagnosing the infected prosthesis has yet to be established. Antimicrobial peptides bind to bacterial cell membranes and are infection specific. Data suggest that these agents may be useful for diagnosing prosthetic joint infection, but large scale studies have yet to be undertaken. Although for many years nuclear medicine has focused on diagnosing prosthetic joint infection, the advent of hybrid imaging with single-photon emission computed tomography(SPECT)/electronic computer X-ray tomography technique (CT) and the availability of fluorine-18 fluoride PET suggests that the diagnostic paradigm may be shifting again. By providing the anatomic information lacking in conventional radionuclide studies, there is renewed interest in bone scintigraphy, performed as a SPECT/CT procedure, for detecting joint instability, mechanical loosening and component malpositioning. Fluoride-PET may provide new insights into periprosthetic bone metabolism. The objective of this manuscript is to provide a comprehensive review of the evolution of nuclear medicine imaging of joint replacements.
84 citations
References
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TL;DR: A functional approximation to earlier exact results is shown to have excellent agreement with the exact results and one can use it easily without intensive numerical computation.
Abstract: A method is developed to calculate the required number of subjects k in a reliability study, where reliability is measured using the intraclass correlation rho. The method is based on a functional approximation to earlier exact results. The approximation is shown to have excellent agreement with the exact results and one can use it easily without intensive numerical computation. Optimal design configurations are also discussed; for reliability values of about 40 per cent or higher, use of two or three observations per subject will minimize the total number of observations required.
1,795 citations
"A novel standardized algorithm for ..." refers methods in this paper
...Sample size was calculated according to the reported estimates for reliability studies using intraclass correlation coefficients (ICCs) [33]....
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TL;DR: In this article, the epicondylar axis and tibial tubercle were used as references on computed tomography scans to measure quantitatively rotational alignment of the femoral and Tibial components.
Abstract: Thirty patients with isolated patellofemoral complications after total knee arthroplasty were compared with 20 patients with well functioning total knee replacements without patellofemoral complications. The epicondylar axis and tibial tubercle were used as references on computed tomography scans to measure quantitatively rotational alignment of the femoral and tibial components. The group with patellofemoral complications had excessive combined (tibial plus femoral) internal component rotation. This excessive combined internal rotation was directly proportional to the severity of the patellofemoral complication. Small amounts of combined internal rotation (1°-4°) correlated with lateral tracking and patellar tilting. Moderate combined internal rotation (3°-8°) correlated with patellar subluxation. Large amounts of combined internal rotational (7°-17°) correlated with early patellar dislocation or late patellar prosthesis failure. The control group was in combined external rotation (10°-0°). The direct correlation of combined (femoral and tibial) internal component rotation to the severity of the patellofemoral complication suggests that internal component rotation may be the predominant cause of patellofemoral complications in patients with normal axial alignment. The epicondylar axis and tibial tubercle are reproducible landmarks which are visible on computed tomography scans and can be used intraoperatively. Using this computed tomography study can determine whether rotational malalignment is present and thus, whether revision of one or both components may be indicated.
975 citations
"A novel standardized algorithm for ..." refers result in this paper
...In contrast to others, the measurements were not performed on axial computer tomography sections, but on 3D reconstructed CT scans, which were first aligned to standardized frames of reference [4, 34]....
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TL;DR: All patients undergoing cruciate-retaining primary total knee arthroplasty for degenerative osteoarthritis at one center were studied prospectively and component malrotation is a significant factor in the development of anterior knee pain after total knee ligation.
Abstract: All patients undergoing cruciate-retaining primary total knee arthroplasty for degenerative osteoarthritis at one center were studied prospectively. Clinical and radiographic followup was obtained at a minimum 5 years in 102 knees in 73 patients. Patients were asked specifically about the presence of the pain in the anterior aspect of the knee in the vicinity of the patella and rated the severity of the pain on a visual analog scale. Significant anterior knee pain rating at least 3 of 10 on the visual analog scale was present in 16 knees (13 patients). Eleven patients with 14 symptomatic knees agreed to undergo computed tomography scanning to accurately determine the rotation of the tibial and femoral components. The epicondylar axis and tibial tubercle were used as references using a previously validated technique. A control group of 11 asymptomatic patients (14 knees), matched for age, gender, and length of followup also underwent computed tomography scanning. All patients in both groups had normal axial alignment. There was a highly significant difference in tibial component rotation between the two groups with the patients with anterior knee pain averaging 6.2 degrees internal rotation compared with 0.4 degrees external rotation in the control group. There also was a significant difference in combined component rotation with the patients with anterior knee pain averaging 4.7 degrees internal rotation compared with 2.6 degrees external rotation in the control group. There was no significant difference in the degree of radiographic patellar tilt or patellar subluxation between the two groups. Patients with combined component internal rotation were more than five times as likely to experience anterior knee pain after total knee arthroplasty compared with those with combined component external rotation. Component malrotation is a significant factor in the development of anterior knee pain after total knee arthroplasty.
546 citations
"A novel standardized algorithm for ..." refers background in this paper
...However, these numbers may underestimate the problem as most of the authors measured the postoperative component rotation either on radiographs or on axial CT scans [3, 16, 31, 32, 34]....
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...[3] reported that a femoral or tibial malalignment of greater than 3 degrees occurred in 16 and 11% of patients after non-navigated TKA....
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...Rotational malalignment of the femoral or tibial prosthetic components have been determined as one of the main causes of poor clinical outcome after TKA [3, 9, 19, 29]....
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...Rotational malalignment is known to cause pain, stiffness, instability and patellofemoral complications [3, 29, 34]....
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TL;DR: Patients with a low cumulative error score had a better functional outcome and their length of stay in hospital was 2 days shorter and trends were identified for better function with good sagittal and rotational femoral alignment and good Sagittal and coronal tibial alignment.
Abstract: The aim of this study was to identify what aspects of implant alignment and rotation affect functional outcome after total knee arthroplasty (TKA). One hundred and fifty-nine total knee arthroplasties were performed at the authors' institution between May 2003 and July 2004. All patients underwent an objective and independent clinical and radiological assessment before and after surgery. A computed tomography scan was performed at 6 months. The alignment parameters that were measured included sagittal femoral, coronal femoral, rotational femoral, sagittal tibial, coronal tibial, and femorotibial mismatch. The cumulative error score, which represents the sum of the individual errors, was calculated. Functional outcome was measured using the Knee Society Score. Good coronal femoral alignment was associated with better function at 1 year (P = .013). Trends were identified for better function with good sagittal and rotational femoral alignment and good sagittal and coronal tibial alignment. Patients with a low cumulative error score had a better functional outcome (P = .015). These patients rehabilitated more quickly and their length of stay in hospital was 2 days shorter.
339 citations
"A novel standardized algorithm for ..." refers background in this paper
...Rotational malalignment of the femoral or tibial prosthetic components have been determined as one of the main causes of poor clinical outcome after TKA [3, 9, 19, 29]....
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TL;DR: The computer-assisted total knee replacements showed better alignment in rotation and flexion of the femoral component, the posterior slope of the tibial component and in the matching of the Femoral and tibia components in rotation.
Abstract: A controlled study, comparing computer- and conventional jig-assisted total knee replacement in six cadavers is presented. In order to provide a quantitative assessment of the alignment of the replacements, a CT-based technique which measures seven parameters of alignment has been devised and used. In this a multi-slice CT machine scanned in 2.5 mm slices from the acetabular roof to the dome of the talus with the subject's legs held in a standard position. The mechanical and anatomical axes were identified, from three-dimensional landmarks, in both anteroposterior and lateral planes. The coronal and sagittal alignment of the prosthesis was then measured against the axes. The rotation of the femoral component was measured relative to the transepicondylar axis. The rotation of the tibial component was measured with reference to the posterior tibial condyles and the tibial tuberosity. Coupled femorotibial rotational alignment was assessed by superimposition of the femoral and tibial axial images. The radiation dose was 2.7 mSV. The computer-assisted total knee replacements showed better alignment in rotation and flexion of the femoral component, the posterior slope of the tibial component and in the matching of the femoral and tibial components in rotation. Differences were statistically significant and of a magnitude that support extension of computer assistance to the clinical situation.
274 citations
"A novel standardized algorithm for ..." refers background in this paper
...Rotational malalignment of the femoral or tibial prosthetic components have been determined as one of the main causes of poor clinical outcome after TKA [3, 9, 19, 29]....
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