Morphometric Differences of Distal Femoral Cut Surface between Korean Male and Female in Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to evaluate the morphometric differences of distal femoral cut surface between Korean males and females in total knee arthroplasty. MATERIALS AND METHODS: A total of 696 patients (1,008 knees: male 92, female 916) who underwent TKA using NexGen® legacy posteriorstabilized (LPS) (605 knees: male 41, female 564) and PS ADVANCE® medical pivot knee (MPK) (403 knees: male 51, female 352) implants were analyzed prospectively. After distal femoral resection, the mediolateral width (ML) was measured at four points (anterior [Ant], distal anterior [DA], distal posterior [DP], and posterior [Post]) and compared with the ML width of the implant respectively. The aspect ratio (AR=ML/anteroposterior width) and width ratio (WR=Ant ML/DP ML) were calculated. Differences in AR, WR, and fitness between male and female were analyzed. RESULTS: The AR of males was larger than that of females for both LPS and MPK; however, no differences in the WR were observed between males and females. The WR in MPK was larger than that in LPS. For both LPS and MPK, females showed greater anatomical fitness than males, and males had relatively greater incidence of undersize than females. For MPK, there were relatively more cases of overhang in Ant and DA cut surface. These results were consistent with the fact that the WR of implant in MPK was larger than that in LPS. CONCLUSION: Korean males tend to have larger AR and less anatomical fitness of the femoral component than females because of undersize. No difference in WR was observed between Korean males and females. However, the cut surfaces as well as femoral implant of MPK had larger WR than those of LPS. MPK has more overhang on the anterior cut surface than LPS, due to a wider Ant flange (larger WR) of the implant.

Corte femoral distal na artroplastia total de joelho na população brasileira / Distal femoral cut in total knee arthroplasty in a Brazilian population

OBJETIVO:Determinar o ângulo ideal para feitura do corte femoral distal na artroplastia total do joelho em população brasileira.MÉTODOS:Foram estudadas radiografias panorâmicas com carga dos membros inferiores em 79 pacientes (57 mulheres e 22 homens), num total de 107 joelhos com indicação de artroplastia total. Foram traçados o eixo anatômico femoral (EAF), o eixo mecânico femoral (EMF) e o ângulo cervicodiafisário (âCD). O ângulo do corte femoral distal foi determinado pelo encontro entre o EMF e o EAF. O valor do valgo femoral ideal foi comparado entre homens e mulheres e entre joelhos com alinhamento em varo e valgo do membro inferior. O corte femoral distal ideal foi correlacionado ainda com o ângulo cervicodiafisário.RESULTADOS:O ângulo do valgo femoral ideal variou de 4,2 até 8,6 graus, com média de 6,3. O corte femoral distal não mostrou diferença quando comparados pacientes com alinhamento coronal em varo e valgo, sem significância estatística (p = 0,180). Quando comparados homens e mulheres, o valgo femoral ideal não mostrou diferença entre os grupos estatisticamente significante (p = 0,057). O ângulo cervicodiafisário mostrou relação inversa com o corte femoral distal.CONCLUSÕES:A média do ângulo entre os eixos mecânico femoral e anatômico femoral foi de 6,3 graus. Alinhamento coronal pré-operatório, assim como o sexo, não exerceu influência no corte femoral distal. O ângulo cervicodiafisário mostrou relação inversa com o corte femoral distal.

OBJECTIVE: To determine the ideal angle for making the distal femoral cut in total knee arthroplasty in a Brazilian population. METHODS: Panoramic radiographs of the lower limbs bearing weight from 79 patients (57 women and 22 men) were studied, totaling 107 knees with an indication for total knee arthroplasty. The femoral anatomical axis, femoral mechanical axis and cervical-diaphyseal angle were traced out. The angle of the femoral cut was determined from the meeting point between the femoral anatomical and mechanical axes. The ideal degree of femoral valgus was compared between men and women and between knees presenting varus and valgus alignment of the lower limb. The ideal distal femoral cut was also correlated with the cervical-diaphyseal angle. RESULTS: The ideal femoral valgus angle ranged from 4.2 to 8.6 degrees, with a mean of 6.3 degrees. There was no statistically significant difference in the distal femoral cut between patients with coronal varus and valgus alignment (p = 0.180). Comparing men and women, there was no statistically significant difference regarding the ideal femoral valgus between the groups (p = 0.057). The cervical-diaphyseal angle presented an inverse relationship with the distal femoral cut. CONCLUSIONS: The mean angle between the femoral mechanical and anatomical axes was 6.3 degree. Neither preoperative coronal alignment nor sex had any influence on the distal femoral cut. The cervical-diaphyseal angle presented an inverse relationship with the distal femoral cut.