Blackburne-Peel Methods Research Articles

Normal Reference Values of the Blackburne-Peel Ratio for Measuring Patellar Height in an Indian Population.

Background Historically, the quadriceps tendon has the largest sesamoid bone of the body, which is known as the patella. Patellar height is one of the important parameters in assessing patellar stability. The patella height has been found to vary in several diseases. As a result, ratios based on a variety of patellar bone indices are used to determine the norms. This study aimed to determine the typical patella height ratio in Indians, who have different sitting and squatting positions as opposed to Caucasians, by applying the Blackburne-Peel ratio to assesspatellar height whichis an alternative to the conventionalInsall-Salvati ratio. Methodology A total of 100 normal lateral knee radiographs from the Indian population were used in this retrospectivestudy. The Blackburne-Peel method (A/B) was used to calculate the ratios. Itwas calculated as perpendicular length measured from the inferior articular point of the patellato the point perpendicular (A) to the tibial plateau to the length of the articular surface of the patella (B). Results Patella height ratio for men was 0.67 ± 0.01, whereas, for women, it was 0.67 ± 0.02. The ratio did not differ significantly (p > 0.05) from the Western population. Conclusions The normal range of the Blackburne-Peel ratio for the Indian population was established, which can be used as a baseline and can be helpful in establishing patellar height in the Indian population. Similar to previous studies, our study shows that patella height ratios are stable regardless of gender or race and can be used to enhance and restore knee kinematics and functions.

Patellar height measurement in Indonesian normal adult population

BackgroundPatellar height is the distance formed by the patella and the length of the patellar tendon. Patellar height measurement can predispose to various abnormalities in the knee joint. Patellar height can be measured using several sizes, such as the Insall-Salvati ratio (IS), Modified Insall-Salvati ratio (MIS), Caton-Deschamps index (CD), and the Blackburne-Peel (BP) index. In Indonesia, no data on the value of patellar height is available. This study aims to determine the patellar height value in Indonesians and compare if there are differences with the standard values commonly used by other countries. Matherials and methodsThis study is descriptive with 136 research subjects aged 20–40. Data were taken from December 2021 to February 2022. The results of patellar X-ray were measured using the Insall-Salvati, Modified Insall-Salvati, Caton-Deschamps, and Blackburne-Peel methods. ResultsIn the measurement of patellar height, the longest measurement was found in the MIS measurement, while the shortest patellar height was measured using the BP method. The normal value of the IS method is 0.78–1.26, the MIS method is > 1.98, the CD method is 0.79–1.23, and the BP method is 0.70–1.10 for patellar height in Indonesia. This study also shows no significant difference in the value of patellar height between male and female sex using the IS measurement method. ConclusionThere is a difference in the standard value of patellar height, which is commonly used by other countries with the standard value of patellar height in Indonesia, but it is not significant.

O sistema convencional de placa e parafusos na osteotomia tibial alta em cunha de abertura medial é suficientemente estável? Um estudo retrospectivo

ObjectiveOpening‐wedge osteotomy of the proximal tibia is a widely performed procedure for treating medial gonarthrosis in active patients and in the presence of varus malalignment of the lower limb. The fixation method is controversial, and the use of conventional implants has been abandoned in favor of implants with more modern locking screws. The aim of the present clinical study was to assess the maintenance of the correction achieved in cases wherein fixation was performed using conventional implants. MethodsThis retrospective study included 51 patients who underwent opening‐wedge high tibial osteotomy wherein fixation was performed using conventional implants (4.5‐mm DCP plate and non‐locking screws). Radiological findings regarding patellar height, tibial slope, and varus correction postoperatively and after consolidation were analyzed to assess the maintenance of the correction achieved by osteotomy. ResultsThe mean loss of correction angle, calculated by the difference between the correction angle in the immediate postoperative period and that after consolidation, was 0.92°±0.9°. In addition, changes in patellar height determined by the Blackburne–Peel method and in the sagittal slope of the tibial plateau were not significant or clinically relevant. ConclusionsThe use of conventional plates and screws is viable in the fixation of opening‐wedge high tibial osteotomy because they provide enough stability to maintain the achieved correction until consolidation, without significant changes.

Conventional plate and screws in medial opening-wedge high tibial osteotomy: are they sufficiently stable? A retrospective study

ObjectiveOpening-wedge osteotomy of the proximal tibia is a widely performed procedure for treating medial gonarthrosis in active patients and in the presence of varus malalignment of the lower limb. The fixation method is controversial, and the use of conventional implants has been abandoned in favor of implants with more modern locking screws. The aim of the present clinical study was to assess the maintenance of the correction achieved in cases wherein fixation was performed using conventional implants. MethodsThis retrospective study included 51 patients who underwent opening-wedge high tibial osteotomy wherein fixation was performed using conventional implants (4.5-mm DCP plate and non-locking screws). Radiological findings regarding patellar height, tibial slope, and varus correction postoperatively and after consolidation were analyzed to assess the maintenance of the correction achieved by osteotomy. ResultsThe mean loss of correction angle, calculated by the difference between the correction angle in the immediate postoperative period and that after consolidation, was 0.92°±0.9°. In addition, changes in patellar height determined by the Blackburne–Peel method and in the sagittal slope of the tibial plateau were not significant or clinically relevant. ConclusionsThe use of conventional plates and screws is viable in the fixation of opening-wedge high tibial osteotomy because they provide enough stability to maintain the achieved correction until consolidation, without significant changes.

Plateau-patella angle in evaluation of patellar height in osteoarthritis

BackgroundThe plateau-patella angle (PPA), recently introduced as a new and simpler method of measuring patellar height from the lateral radiograph, has the advantage of simplicity over previously described methods as it involves a single angular measurement without the need for calculations. The purpose of this study was to validate the use of the PPA as a measurement for patellar height in knees with moderate to severe osteoarthritis. MethodsA total of 331 patients who underwent total knee arthroplasty at our institution with radiographs prior to surgery were evaluated. Of those, 297 (89.2%) were felt to be adequate for review. Three observers with different levels of orthopedic training measured PPA, Insall–Salvati, Caton–Deschamps, and Blackburne–Peel indices on a subset of 50 consecutive patients. Interobserver agreement for each of the four measurements was calculated and correlation between each of the measurements within each observer was calculated. The measurement of the PPA was repeated. Intraobserver agreement for the PPA was determined and a normal range and distribution was defined for this population. ResultsFor the three observers, the mean PPA for the entire cohort was 25.55, 25.31, and 24.42. The intraclass correlation coefficient (ICC) was 0.81, The ICC and intraobserver assessment were the highest for the PPA compared with the other ratios. The PPA was found to correlate most strongly with the Blackburne–Peel method. ConclusionsThe plateau-patella angle is a reliable way to evaluate patellar height in the osteoarthritic population. The measurement demonstrated a higher interobserver reliability compared with previously described methods. Level of evidenceRetrospective Level IV.

Multimodality correlations of patellar height measurement on X-ray, CT, and MRI

To investigate whether the universally accepted range of normal patellar height ratios derived from radiography for the Insall-Salvati (IS) and Blackburne-Peel (BP) methods could be similarly applied to both CT and MRI. Institutional review board approval was obtained with waiver of informed consent for this HIPPA-compliant study. A total of 45 knees in 42 patients (15 men, 27 women; age range 11 to 75 years, mean age 39 ± 20 years) who underwent tri-modality (radiograph, CT, and MRI) examinations were selected. All patients had knee imaging obtained for a variety of reasons and measurements were performed by two independent readers who were blinded to each other's measurements or the respective measurements derived from each of the methods. Paired t test was used to compare the mean values among the modalities. Inter-observer and inter-method agreements were assessed using intra-class correlation coefficients. Statistically significant, but small quantitative differences are noted between tri-modality patellar height ratios. For comparable results, the small addition of 0.13 and 0.10 are needed for the Insall-Salvati measurements on MRI and CT respectively, compared with radiographs. For the Blackburne-Peel ratio, an additional adjustment of 0.09 is needed between radiographs and MRI, but not between radiographs and CT. These adjustments are independent of gender. The interobserver reproducibility was excellent (ICC ≥ 0.94) for both the Insall-Salvati and Blackburne-Peel methods for all modalities. The results indicate that cut-off values for patella alta and baja derived from radiographs should not be directly transposed to CT and MRI; however, the adjustments are relatively minor. These measurements show excellent reproducibility for all modalities currently used for patellar height measurements.

Avaliação comparativa da altura patelar pós-artroplastias totais do joelho com e sem preservação do ligamento cruzado posterior

OBJETIVO: Avaliar possíveis alterações na altura da patela, pós-artroplastias totais do joelho com e sem preservação do ligamento cruzado posterior (LCP). MÉTODO: Foram analisadas radiografias pré e pós-operatórias, de 120 pacientes submetidos a artroplastias totais do joelho, realizadas no Instituto Nacional de Traumatologia e Ortopedia, no período compreendido entre janeiro de 2003 e janeiro de 2005, com implantes do tipo Johnson de plataforma rotatória. A amostra foi dividida em dois grupos, correspondendo o grupo I a exames radiográficos pré e pós-artroplastias totais do joelho com preservação do LCP (n = 60) e o grupo II, a exames radiográficos pré e pós-artroplastias sem preservação do LCP (n = 60). Para a mensuração dos valores pré e pós-operatórios foi utilizado o método de Blackburne-Peel, cujo valor normal é igual a 0,8 (± 0,2), variando, portanto, entre 0,6 e 1. RESULTADOS: O índice patelar médio pré-operatório do grupo I foi igual a 0,874 e, no grupo II, a média foi igual a 0,857. O índice médio de altura patelar pós-operatório do grupo I foi igual a 0,849, variando entre 0,54 e 1,03. No grupo II, o menor índice foi igual a 0,48, o maior igual a 0,94, sendo o índice médio igual a 0,79. A comparação dos valores pós-operatórios nos dois grupos apresentou diferença estatisticamente significativa (p < 0,05). Conclusões: Foi observada tendência à diminuição da altura patelar em ambos os grupos estudados, sendo esta mais evidente no grupo em que houve sacrifício do LCP.

Changes in patellar height and tibia inclination angle following open-wedge high tibial osteotomy

We investigated changes in patellar height and tibial inclination angle after open-wedge high tibial osteotomy and the effect of these changes on patient satisfaction. The study included 18 knees of 16 patients (4 males, 12 females; mean age 55 years; range 44 to 66 years) who underwent open-wedge proximal tibial osteotomy with autogenous bone graft and medial plate for medial compartment gonarthrosis. Nine knees (50%) had Ahlbäck grade I, eight knees (44.4%) had grade II, and one knee (5.6%) had grade III osteoarthritis. Pre- and postoperatively, femorotibial angle, tibial inclination angle, and patellar height were measured according to the Bauer, Harvey-Moore, and Blackburne-Peel methods, respectively. Clinical evaluations were made using the Lysholm-Gillquist score. Patient satisfaction was questioned with a 10-point scale. The mean follow-up was 54.2 months (range 25 to 96 months). Postoperatively, the mean correction of the femorotibial angle was 13.6 degrees (p<0.05), and the mean increase in the tibial inclination angle was 2.9 degrees (p<0.05). Fifteen knees (83.3%) exhibited a significant decrease in patellar height by a mean of 15% (p<0.05). The mean Lysholm-Gillquist score increased from preoperative 61 to 86 at the latest follow-up (p<0.05). The results were excellent in 11 knees (61.1%), good in six knees (33.3), and poor in one knee (5.6%). The mean patient satisfaction score was 8.1 (range 5 to 10). Changes in the femorotibial angle and Lysholm-Gillquist score were significantly correlated with patient satisfaction (p<0.05). Three patients had nonunion, perioperative intra-articular fracture, and superficial wound infection, respectively. Changes in the tibial inclination angle and patellar height following open-wedge tibial osteotomy do not have an adverse effect on short-term patient satisfaction.

Interobserver variation in the measurement of patellar height after total knee arthroplasty

We assessed the reproducibility and accuracy of four ratios used to measure patellar height, namely the Blackburne-Peel, Caton-Deschamps, Insall-Salvati and modified Insall-Salvati, before and after total knee arthroplasty. The patellar height was measured, by means of the four ratios, on the pre- and post-operative lateral radiographs of 44 patients (45 knees) who had undergone total knee arthroplasty. Two independent observers measured the films sequentially, in identical conditions, totalling 720 measurements per observer. Statistical analysis, comparing both observers and ratios, was carried out using the intraclass correlation coefficient. Before operation there was greater interobserver variation using either the Insall-Salvati or modified Insall-Salvati ratios than when using the Caton-Deschamps or Blackburne-Peel methods. This was because of difficulty in identifying the insertion of the patellar tendon. Before operation, there was a minimal difference in reliability between these methods. After operation the interobserver difference was greatly reduced using both the Caton-Deschamps and Blackburne-Peel methods, which use the prosthetic joint line, compared with the Insall-Salvati and modified Insall-Salvati, which reference from the insertion of the patellar tendon. The theoretical advantage of using the Insall-Salvati and modified Insall-Salvati ratios in measuring true patellar height after total knee arthroplasty needs to be balanced against their significant interobserver variability and inferior reliability when compared with other ratios.

Anterior opening wedge osteotomy of the proximal tibia for anterior knee pain in idiopathic hyperextension knees

We analysed 20 patients with 24 knees affected by idiopathic genu recurvatum who were treated with an anterior opening wedge osteotomy of the proximal tibia because of anterior knee pain. We managed to attain full satisfaction in 83% of the patients with a mean follow-up of 7.4 years. The mean Hospital for Special Surgery score was 90.3 (range 70.5-99.5), and the mean Knee Society score score was 94.6 (70-100) for function and 87.7 (47-100) for pain. The mean Western Ontario and McMaster University Osteoarthritis Index score for knee function was 87.5 (42-100), for stiffness 82.8 (25-100) and for pain 87.3 (55-100). Radiographs showed a significant increase in posterior tibial slope of 9.4 deg and a significant decrease of patellar height according to the Blackburne-Peel method of 0.16 postoperatively. No cases of non-union, deep infection or compartment syndrome were seen. No osteoarthritic changes in the lateral or medial knee compartment were found with more than 5 years' follow-up in 16 patients with 19 affected knees. Three out of the four dissatisfied patients had a patella infera which led to patellofemoral complaints. One patient in the study underwent a secondary superior displacement of the patella with excellent results. We conclude that in a selected group of patients with idiopathic genu recurvatum and anterior knee pain an opening wedge osteotomy of the proximal tibia can be beneficial.