Evaluation of an innovative new method for quantitation of plasma cells on CD138 immunohistochemistry

AimTo compare the frequently used CD138 immunohistochemistry-based method of plasma cell quantitation, to a proposed new method, using interobserver and intraobserver concordance parameters.MethodsArchival CD138 immunohistochemically stained slides made from paraffin-embedded bone marrow biopsies of 33 patients with a confirmed diagnosis of multiple myeloma were used. Light microscopic examination was performed using low magnification lenses (10×) for both the overview estimation method (method A) and the new method (method B), and high magnification lenses (50×), for method B only. For method B, reviewers selected three areas with low, intermediate and high plasma cell densities using 10× lenses. Using a well-defined technique, the 50× lens was then used to count plasma cells as a percentage of all nucleated cells. After blinded relabelling of all the slides, the nine reviewers repeated the plasma cell quantitation using both methods. The plasma cell counts were obtained, and the review times were recorded.ResultsOverall intraobserver concordance was comparable for method A (concordance correlation coefficient (CCC)=0.840) and method B (CCC=0.733). Interobserver concordance for method A (intraclass correlation coefficient (ICC)=0.793 and 0.713) and method B (ICC=0.657 and 0.658) indicated high similarity between reviewers. Method A showed poor interobserver concordance (ICC=0.105) at low plasma cell densities.ConclusionsThe new method is comparable to the frequently used overview estimation method in terms of intraobserver and interobserver concordance, and cost. The new method has superior interobserver concordance at low plasma cell densities. The new method appears more amenable to digital scanning and analysis.

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Automated digital enumeration of plasma cells in bone marrow trephine biopsies of multiple myeloma

Journal of Clinical Pathology ◽

10.1136/jclinpath-2020-207066 ◽

2020 ◽

pp. jclinpath-2020-207066

Author(s):

Jacques A J Malherbe ◽

Kathryn A Fuller ◽

Bob Mirzai ◽

Bradley M Augustson ◽

Wendy N Erber

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Plasma Cells ◽

Intraclass Correlation ◽

Antigen Expression ◽

Bone Marrow Biopsies ◽

Bone Marrow Trephine ◽

Bone Marrow Trephine Biopsy ◽

Plasma Cell Neoplasms

AimsDetermination of the number of plasma cells in bone marrow biopsies is required for the diagnosis and ongoing evaluation of plasma cell neoplasms. We developed an automated digital enumeration platform to assess plasma cells identified by antigen expression in whole bone marrow sections in multiple myeloma, and compared it with manual assessments.MethodsBone marrow trephine biopsy specimens from 91 patients with multiple myeloma at diagnosis, remission and relapse were stained for CD138 and multiple myeloma oncogene 1 (MUM1). Manual assessment and digital quantification were performed for plasma cells in the entire trephine section. Concordance rates between manual and digital methods were evaluated for each antigen by intraclass correlation analyses (ICC) with associated Spearman’s correlations.ResultsThe digital platform counted 16 484–1 118 868 cells and the per cent CD138 and MUM1-positive plasma cells ranged from 0.05% to 93.5%. Overall concordance between digital and manual methods was 0.63 for CD138 and 0.89 for MUM1. Concordance was highest with diffuse plasma cell infiltrates (MUM1: ICC=0.90) and lowest when in microaggregates (CD138: ICC=0.13). Manual counts exceeded digital quantifications for both antigens (CD138: mean=26.4%; MUM1: mean=9.7%). Diagnostic or relapse threshold counts, as determined by CD138 manual assessments, were not reached with digital counting for 16 cases (18%).ConclusionsAutomated digital enumeration of the entire, immunohistochemically stained bone marrow biopsy section can accurately determine plasma cell burden, irrespective of pattern and extent of disease (as low as 0.05%). This increases precision over manual visual assessments which tend to overestimate plasma burden, especially for CD138, and when plasma cells are in clusters.

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Do patients with MGUS require a bone marrow biopsy?

Journal of Clinical Oncology ◽

10.1200/jco.2007.25.18_suppl.8117 ◽

2007 ◽

Vol 25 (18_suppl) ◽

pp. 8117-8117

Author(s):

J. Singh ◽

A. K. Malani ◽

C. H. Huang ◽

M. Hashmi ◽

S. C. Mathur ◽

...

Keyword(s):

Bone Marrow ◽

Regression Analysis ◽

Bone Marrow Biopsy ◽

Plasma Cell ◽

Linear Correlation ◽

Plasma Cells ◽

Bone Marrow Biopsies ◽

Cell Percentage ◽

Serum Igg ◽

Immunoglobulin Levels

8117 Monoclonal gammopathy of undetermined significance (MGUS) increase in prevalence with age and it is associated with risk of progression to plasma cell disorder. According to ASH guidelines, patients (pts) should have a complete blood count (CBC), creatinine, calcium, and a complete bone survey and periodic follow up. There has been no clear-cut guideline regarding the role of bone marrow biopsy in these patients. There is suggestion in the literature that bone marrow aspiration and biopsy is indicated if the M protein is 1.5 g/dL. Hypothesis We hypothesize that the increase in serum immunoglobulin is correlated with an increase in plasma cell in the bone marrow biopsy. Methods: We performed a retrospective chart review of 327 MGUS veteran patients seen from 2002 to 2005. Diagnostic criteria for MGUS were defined as <3 g/dL serum monoclonal protein, <10 % plasma cells in the bone marrow and absence of radiographic or laboratory abnormality related to the plasma cell proliferative process. Patients with smoldering myeloma were excluded. Bone marrow biopsies were available on 97/327 patients. Bone marrow biopsy with plasma cell percentage, serum protein electrophoresis (SPEP) and immunofixation (SFE), and immunoglobulin levels of these patients were retrieved and statistical analysis was performed by using Pearson correlation coefficient and linear regression analysis to detect the correlation between plasma cell percentage and immunoglobulin levels. Results: Of the 97 patients whom the bone marrow biopsy was available, 66 patients had IgG, 15 had IgA and 16 had IgM monoclonal paraprotein. There was linear correlation between serum IgG and IgA levels with the percentage of plasma cells in the bone marrow. (p< 0.001 and < 0.02 respectively. By regression analysis, using a cut off value of 10% plasma cells in the bone marrow, the predicted level of IgG and IgA immunoglobulin was 2124 mg /dl and 1564 mg/dl respectively. There was no correlation between IgM immunoglobulin and plasma cell percentage in the marrow. Conclusion: There is a linear correlation between serum IgG and IgA immunoglobulin with plasma cell percentage in the bone marrow. Bone marrow biopsy with plasma cell percentage of 10% or higher may be predicted in patients with MGUS with IgG or IGA above 2g/dl and 1.5g/dl respectively. No significant financial relationships to disclose.

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T and B lymphocyte abnormalities in bone marrow biopsies of common variable immunodeficiency

Blood ◽

10.1182/blood-2010-11-321695 ◽

2011 ◽

Vol 118 (2) ◽

pp. 309-318 ◽

Cited By ~ 66

Author(s):

Manuella L. Gomes Ochtrop ◽

Sigune Goldacker ◽

Annette M. May ◽

Marta Rizzi ◽

Ruth Draeger ◽

...

Keyword(s):

Bone Marrow ◽

T Cell ◽

B Cell ◽

Common Variable Immunodeficiency ◽

Plasma Cells ◽

Cell Development ◽

B Cell Development ◽

Bone Marrow Biopsies ◽

Cell Counts ◽

Common Variable

Abstract In common variable immunodeficiency (CVID) defects in early stages of B-cell development, bone marrow (BM) plasma cells and T lymphocytes have not been studied systematically. Here we report the first morphologic and flow cytometric study of B- and T-cell populations in CVID BM biopsies and aspirates. Whereas the hematopoietic compartment showed no major lineage abnormalities, analysis of the lymphoid compartment exhibited major pathologic alterations. In 94% of the patients, BM plasma cells were either absent or significantly reduced and correlated with serum immunoglobulin G levels. Biopsies from CVID patients had significantly more diffuse and nodular CD3+ T lymphocyte infiltrates than biopsies from controls. These infiltrates correlated with autoimmune cytopenia but not with other clinical symptoms or with disease duration and peripheral B-cell counts. Nodular T-cell infiltrates correlated significantly with circulating CD4+CD45R0+ memory T cells, elevated soluble IL2-receptor and neopterin serum levels indicating an activated T-cell compartment in most patients. Nine of 25 patients had a partial block in B-cell development at the pre-B-I to pre-B-II stage. Because the developmental block correlates with lower transitional and mature B-cell counts in the periphery, we propose that these patients might form a new subgroup of CVID patients.

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Quantitation of Monoclonal Plasma Cells in Bone Marrow Biopsies in Plasma Cell Dyscrasia

Analytical Cellular Pathology ◽

10.1155/2003/821978 ◽

2003 ◽

Vol 25 (4) ◽

pp. 167-171 ◽

Cited By ~ 2

Author(s):

G. M. Markey ◽

P. Kettle ◽

T. C. M. Morris ◽

N. Connolly ◽

H. Foster

Keyword(s):

Bone Marrow ◽

Plasma Cell ◽

Plasma Cells ◽

Cell Mass ◽

Observation Time ◽

Plasma Cell Dyscrasia ◽

Bone Marrow Biopsies ◽

Colour Figure ◽

Light Chain Immunoglobulin ◽

Monoclonal Proteins

Direct measurement of monoclonal plasma cell mass in bone marrow biopsies may be a useful parameter to establish in plasma cell dyscrasia. In this study monoclonal plasma cells/mm2in light chain immunoglobulin immunostained archival bone marrow sections from 22 patients in whom a diagnosis of multiple myeloma (MM) had been excluded but who had monoclonal proteins were counted by two observers at light microscopic level. There was good correlation between the counts of the two observers. The levels of monoclonal plasma cells/mm2in biopsies were not related to the % counts in the aspirates taken at the same time as the biopsies. Three of seven patients with biopsy levels in excess of the polyclonal levels in patients without plasma cell dyscrasia developed progressive MM within the observation time. Monoclonal plasma cell levels/mm2of bone marrow biopsies can be measured and they provide a useful parameter for the assessment of patients with low volume plasma cell dyscrasia. Colour figure can be viewed onhttp://www.esacp.org/acp/2003/25‐4/markey.htm.

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Significance of Bone Marrow Plasma Cell Percentage in Patients with Monoclonal Gammopathy of Unknown Significance Developing Multiple Myeloma

Blood ◽

10.1182/blood.v124.21.5688.5688 ◽

2014 ◽

Vol 124 (21) ◽

pp. 5688-5688

Author(s):

Mona L Vekaria ◽

Bharat Rao ◽

Philip Kuriakose

Keyword(s):

Risk Factors ◽

Bone Marrow ◽

Bone Marrow Biopsy ◽

Plasma Cell ◽

Monoclonal Gammopathy ◽

Plasma Cells ◽

Time To Progression ◽

Bone Marrow Biopsies ◽

Monoclonal Protein ◽

Cell Percentage

Abstract Introduction: Monoclonal gammopathies are characterized by the detection of a monoclonal immunoglobulin in the serum or urine and underlying proliferation of a plasma cell/B lymphoid clone. (1) Patients with monoclonal gammopathy of undetermined significance (MGUS) have a clonal plasma cell population in the marrow (<10%) and secrete a monoclonal protein in the serum (<3g/dL) and/or urine. However, they lack clinical features of overt Multiple Myeloma (MM) (lytic bone lesions, anemia, renal impairment and hypercalcemia). In a study from the Mayo Clinic, 59 of 241 patients with MGUS (24%) developed MM over a period of 22 years. (2) The interval from recognition of monoclonal protein to diagnosis of MM ranged from 2-29 years, indicating that patients with MGUS need to be followed indefinitely. Many risk factors have been looked at to identify those with MGUS who are at the highest risk to progress into MM. We hypothesize that a higher number of plasma cells would correlate with a greater risk of progression to MM and sought to find out if this could be documented by arbitrarily dividing patients between < or ≥5% plasma cells seen on initial bone marrow biopsy. Methods: We retrospectively reviewed patients diagnosed with MGUS at Henry Ford Hospital between 1999-2013 who underwent a bone marrow biopsy for documenting plasma cell percentage. In addition to this, we also recorded serum hemoglobin, calcium, creatinine, monoclonal protein type and amount, serum free light chains, beta-2 microglobulin and urine for monoclonal protein at the time of diagnosis of MGUS as well as last completed values. For patients that had skeletal surveys we noted if lytic lesions were present at diagnosis, as well as cytogenetics and karyotype evaluations on bone marrow biopsy samples, if completed. Results: 120 patients with bone marrow biopsies were reviewed. Out of this 17 patients were noted from initial bone marrow biopsy to have ≥10% plasma cells. The remaining 103 patients were categorized as having MGUS. While we were not able to complete full statistical analyses, we did note that 14 of these 103 (13.6%) patients went on to develop overt MM. Further evaluation of these patients revealed that 8 of 14 (57%) had bone marrow biopsies showing ≥5% plasma cells. Interestingly the average time to progression into MM in this subgroup was 1,879 days whereas in the 6 of 14 (43%) with bone marrow biopsy showing <5% plasma cells had average time to progression into MM of 1,965 days. Abnormal cytogenetics and karyotypes of the bone marrow biopsy were also seen in 37.5% of the subgroup of patients with ≥5% plasma cells whereas it was only seen in 16.7% of the subgroup of patients with <5% plasma cells. With statistical data analyses we hope to prove significance in the above collected data as well as make further correlations in regards to risk factors in patients with MGUS. Conclusion: While we have not been able to complete full statistical analyses of the collected data yet, basic review of the above patients with MGUS and ≥5% plasma cells in the bone marrow biopsy showed a trend to develop MM faster by an average of 86 days than those that had <5% plasma cells. These same patients also were more likely to have abnormal cytogenetics and karyotypes of their bone marrow biopsies. There is a need for further investigations to be done in patients with MGUS and higher risk features. It is important that hematologists be able to recognize a high risk MGUS patient as this would lead to closer monitoring and consideration for earlier aggressive treatment to potentially delay progression into overt MM. Disclosures No relevant conflicts of interest to declare.

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Biofilms and inflammation in patients with chronic rhinosinusitis

Medicine and Pharmacy Reports ◽

10.15386/mpr-1691 ◽

2020 ◽

Author(s):

Lavinia-Gianina Manciula ◽

Ionut Isaia Jeican ◽

Lucian Barbu Tudoran ◽

Silviu Albu

Keyword(s):

Chronic Rhinosinusitis ◽

Plasma Cell ◽

Nasal Polyps ◽

Nasal Polyposis ◽

Inflammatory Cell ◽

Plasma Cells ◽

Strongly Correlated ◽

Cell Counts ◽

Deviated Septum ◽

Nasal Pathology

Introduction. The aim of the present study is to evaluate the presence of biofilms in patients with chronic rhinosinusitis (CRS), with or without nasal polyps, and their relationship to eosinophils and plasma cells. We compared the results with those obtained in nonCRS patients. Methods. A total of 50 patients were included in the study, 30 CRSwNP patients, 10 CRSsNP cases and 10 control patients who were operated for deviated septum. Biofilm detection was performed by means of H&E staining and SEM. Eosinophil and plasma cell values were recorded and compared between groups. Results. Biofilms were identified in 30 patients (60%), 76.6% (23 out of 30) of the CRSwNP patients, 70% (7 out of 10) of the CRSsNP patients and none of the septoplasty patients. Eosinophil and plasma cell values were more elevated in CRS patients, being strongly correlated to biofilm presence and nasal polyposis. Conclusion. Biofilm presence was demonstrated in many of the CRS patients, with no evidence in the control cases. Our study findings indicate that inflammatory cell counts are higher in patients with CRS compared to controls, but also more elevated in patients with polyposis. In biofilm-positive patients, eosinophil and plasma cell counts were greater than those in patients without biofilms, demonstrating the proinflammatory action of the biofilm in the sino-nasal pathology.

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AL Amyloidosis and Concomitant Myeloma: Time to Reconsider Assumptions

Blood ◽

10.1182/blood.v116.21.4044.4044 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4044-4044

Author(s):

Wesley Witteles ◽

Ronald Witteles ◽

Michaela Liedtke ◽

Sally Arai ◽

Richard Lafayette ◽

...

Keyword(s):

Bone Marrow ◽

Overall Survival ◽

Plasma Cell ◽

Research Funding ◽

Plasma Cells ◽

Renal Involvement ◽

World Health ◽

Bone Lesions ◽

Al Amyloidosis ◽

Bone Marrow Biopsies

Abstract Abstract 4044 Background: Conventionally, multiple myeloma is believed to coexist in approximately 10% of AL amyloidosis patients. However, it is unclear whether this figure is too low based on current World Health Organization criteria. These criteria, mainly created to differentiate myeloma from monoclonal gammopathy of undetermined significance, include the presence of ≥ 10% plasma cells on a bone marrow biopsy or aspirate as being diagnostic of myeloma. Aims: To define the frequency and relevance of a concomitant diagnosis of myeloma in patients with AL amyloidosis. Methods: Records from consecutive patients with biopsy-proven AL amyloidosis treated at the Stanford University Amyloid Center were reviewed. Plasma cell percentages were determined by manual counts from bone marrow aspirate smears and by CD138 immunohistochemistry (IHC) performed on bone marrow core biopsies. Results: A total of 41 patients (median age 61 years, 32% female) were evaluated. The median number of organs involved with amyloidosis was 2 (range 1–4), with 28 patients (68%) having cardiac involvement, 22 patients (54%) having renal involvement, 15 patients (37%) having gastrointestinal involvement, 12 patients (29%) having soft tissue involvement, and 10 patients (24%) having nervous system involvement. All patients had bone marrow biopsies and aspirates performed at the time of amyloid diagnosis, with most undergoing both manual counts of plasma cells from aspirates and IHC from core biopsies. Based on conventional criteria, manual aspirate counts defined 15/28 (54%) patients as having myeloma, and IHC defined 26/31 (84%) patients as having myeloma (p=0.01). Only nine patients had a detectable serum paraprotein on immunofixation (median 1.1 g/dl, range 0.4–2.6). 81% of patients had an elevated serum free light chain (85% lambda), with a median level of 37.3 mg/dl (range 8.6–256 mg/dl). Compared to the frequency of elevated plasma cells, the prevalence of anemia (29%), hypercalcemia (14%), impaired kidney function (21%), and lytic lesions (7%) was low. After a median follow-up of 13 months (range 1–127 months), the one-year overall survival (74% vs. 58%) and three-year overall survival (50% vs. 50%) was not significantly different between patients with ≥10% plasma cells and patients with <10% plasma cells (p=NS). Discussion: As defined by bone marrow plasma cell involvement, a strikingly high percentage (84%) of AL amyloidosis patients would be considered to have concurrent myeloma. This figure is much higher than has been traditionally quoted in the literature, likely due to the utilization of newer methods of counting plasma cells. There was a low prevalence of myeloma-associated end-organ effects (hypercalcemia, anemia, renal insufficiency, lytic bone lesions), and a myeloma diagnosis had no impact on survival. Conclusion: In this cohort of AL amyloid patients, concomitant myeloma was present in the vast majority of patients using modern diagnostic techniques. The significance of this diagnosis appears to be minimal – calling into question whether the diagnostic criteria for myeloma should be redefined in this population. Disclosures: Witteles: Celgene: Research Funding. Liedtke:Celgene: Lecture fee, Research Funding. Schrier:Celgene: Research Funding.

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Observations On Eosinophil Ifiltrates in The Bone Marrow Of Patients With Multiple Myeloma. Clinicopathological Correlates

Blood ◽

10.1182/blood.v122.21.5338.5338 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5338-5338

Author(s):

Finella MC Brito-Babapulle ◽

Tanya Cranfield ◽

Robert B Corser ◽

Helen Dignum ◽

Christopher James ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Plasma Cells ◽

Conflicts Of Interest ◽

Osteolytic Lesion ◽

Inverse Correlation ◽

Eosinophil Infiltration ◽

Bone Marrow Biopsies ◽

Lytic Lesions

Abstract Mouse eosinophils have been shown in 2011 to be required for the maintenance of long lasting plasma cells in the bone marrow and in maintaining the bone marrow plasma cell microenvironment. Human eosinophils have been shown by Wong et al to support multiple myeloma cell proliferation via a mechanism independent of IL6. We looked at bone marrow biopsies taken from patients who had a paraprotein and in whom a diagnosis of multiple myeloma was suspected. These samples were taken solely for the purposes of diagnosisng multiple myeloma and were retrospectively reviewed from the point of view of degree of eosinophil infiltration and its correlation with tumour load, bone lytic lesions, plasma cell morphology, whether blastic, crystalline inclusions, Mott cells, flame cells and or lymphoplasmacytoid. There were no cases of IGD or E myeloma or osteosclerotic myeloma.Nonsecretory myeloma and cases of light chain myeloma with or without amyloid were included in the series. Biopsies were not performed from osteolytic lesion unless biopsy was necessary to make a diagnosis of myeloma. Myeloma was diagnosed when plasma cell infiltrate was greater than 10% on bone marrow aspirate with a paraprotein and or lytic lesions. Eosinophil infiltration did not correlate with any of the tumour clinicopathological markers but showed an inverse correlation with degree of plasmacytosis. Eosinophils were hardly ever found in marrow aspirates that had over 70% plasma cells. They were usually found in trephine sections of bone marrow in areas where there was Grade I/II fibrosis and were often found in close proximity to focal areas of plasma cell infiltration. Whether eosinophils play a role in preventing or maintaining malignant plasma cell recurrence is currently being studied. Disclosures: No relevant conflicts of interest to declare.

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Numerous IgG4-positive plasma cells are ubiquitous in diverse localised non-specific chronic inflammatory conditions and need to be distinguished from IgG4-related systemic disorders

Journal of Clinical Pathology ◽

10.1136/jcp.2010.085613 ◽

2011 ◽

Vol 64 (3) ◽

pp. 237-243 ◽

Cited By ~ 210

Author(s):

Johanna D Strehl ◽

Arndt Hartmann ◽

Abbas Agaimy

Keyword(s):

Inflammatory Response ◽

Oral Cavity ◽

Plasma Cell ◽

Plasma Cells ◽

Systemic Disease ◽

High Power Field ◽

Histopathological Features ◽

Inflammatory Conditions ◽

Cell Counts ◽

Gastrointestinal Lesions

BackgroundIgG4-related systemic fibrosclerosis is a recently defined disorder characterised by a diffuse or tumefactive inflammatory reaction rich in IgG4-positive plasma cells associated with sclerosis and obliterative phlebitis. Although characteristic histopathological features are essential for the diagnosis of these disorders, to date there exists no consensus regarding the cut-off values used to define a ‘significant IgG4-positive plasma cell count,’ and data regarding the distribution of IgG4-positive plasma cells under common (non-specific) inflammatory conditions are lacking.MethodsThe authors analysed 121 randomly selected histopathological specimens containing prominent lymphoplasmacytic infiltrates (11 obstructive sialadenitis, 27 inflammatory lesions of the oral cavity, 24 inflammatory gastrointestinal lesions, 15 rheumatoid synovitis, 15 non-specific synovitis, eight non-specific dermatitis and 21 primary carcinomas with a peritumoral inflammatory response). For comparison, seven cases of sclerosing sialadenitis (Küttner tumour) were examined.ResultsHigh counts of IgG4 plasma cells were found in sclerosing sialadenitis (mean 40/high-power field (hpf)), contrasting sharply with sialadenitis caused by sialolithiasis (mean 3/hpf). Greatly varied but generally high counts of IgG4-positive plasma cells were also seen in several of the other lesions, particularly in rheumatoid synovitis (mean 55/hpf), oral cavity lesions (mean 79/hpf) and carcinoma-associated inflammatory response (mean 24/hpf). The mean IgG4/IgG ratios for all lesions varied between 0 and 0.4.ConclusionsThe results demonstrate the ubiquitous occurrence of variably high numbers of IgG4-positive plasma cells under diverse non-specific inflammatory conditions, indicating that high IgG4-positive plasma cell counts and high IgG4/IgG ratios per se do not reliably distinguish IgG4-associated systemic disease from non-specific conditions, and that the IgG4 counts must be cautiously interpreted in the context of appropriate clinical and histopathological features.

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The Axis-patella Index: A New Method for Measuring Patellar Height

10.21203/rs.3.rs-101436/v1 ◽

2020 ◽

Author(s):

Hua Han ◽

Xiaohui Zhang

Keyword(s):

Correlation Coefficient ◽

Reference Range ◽

Articular Surface ◽

Intraclass Correlation ◽

Patellar Height ◽

New Method ◽

Strongly Correlated ◽

Accurate Identification ◽

Adjacent Structures ◽

The Mean

Abstract Background: The widely used methods for measuring patellar height are based on the anatomic landmarks of the patella and the proximal tibia. When the knee undergoes alterations in the articular surface or adjacent structures due to various diseases or operations, the accurate identification of tibial landmarks is challenging. The results of these conventional methods may be biased or even unavailable. The purpose of this study was to introduce and validate a new method, axis-patella index (API), for assessing patellar height. Methods: Patellar heights were respectively measured using the Insall–Salvati, modified Insall–Salvati, Blackburne–Peel, Caton–Deschamps, plateau-patellar angle, and axis-patella methods on the lateral radiographs of 649 knees without anatomic abnormalities. The inter- and intra-observer reliability of all methods were evaluated by calculating intraclass correlation coefficient and Bland-Altman plots. The associations between the API and the established methods were assessed using Pearson’s correlation coefficient. Results: The API was strongly correlated with the five aforementioned methods. Reliability analyses indicated high inter-observer reproducibility and intra-observer repeatability. The mean of API was approximately 1.5, hence the reference range was defined 1.2 - 1.9 according to the 95% confidence interval. Conclusions: The API, a new index of referencing the tibial shaft axis and the fibular head, providing a valid and accurate alternative for the assessment of patellar height. The reference range was 1.2 - 1.9 in radiographically normal knee.

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