Intraoperative morphometric study of distal femur in Brazilian patients undergoing total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is the treatment option for patients with severe osteoarthritis (OA) of the knee whose symptoms are refractory to conservative management. Unfortunately, the level of patient dissatisfaction is high, reaching up to 25%. The reasons for this dissatisfaction are multifactorial, but bone-implant mismatch significantly increases the chance of pain and functional limitation. Sex-specific prosthesis designs have been developed to overcome this issue, but their use is still controversial. The primary objective of this study was to evaluate possible sex differences in the shape of the distal femur in patients with osteoarthritis. Secondary objectives were to investigate interpersonal variability of the distal femur and to determine the number of femoral implant sizes required to meet shape variations. METHODS AND FINDINGS: A cross-sectional observational study prospectively compared 294 knees of 293 patients with osteoarthritis according to sex (201 female/93 male). Six intraoperative measurements were performed on the distal femur (height and width of both lateral and medial condyles, total medial-lateral width of the femur, and intercondylar distance). Sex differences and interpersonal variability were analyzed by multiple linear regressions. Measurements were also correlated with patient height. An optimization analysis was used to estimate the number of femoral implant sizes required. There were significant sex differences in the distal femur, where men had higher values than women in all measurements. Great interpersonal variability was found. The height of the lateral condyle was correlated with patient height, but the correlation was not strong. Twenty-five femoral implant sizes were required to meet the shape variations in our sample. CONCLUSIONS: The shape of the distal femur in patients with osteoarthritis shows great interpersonal variability, with men showing significantly higher values than women. A total of 25 different implant sizes would be necessary to adequately meet the variations observed in our study population.

Evaluation of body mass index as a prognostic factor in osteoarthrosis of the knee.

OBJECTIVE: To evaluate the relationship between patients' body mass index (BMI) and the degree of radiographic severity of knee osteoarthrosis. METHOD: 117 patients with gonarthrosis were evaluated prospectively. The patients' BMI was calculated and their knee arthrosis was classified in accordance with the modified Ahlbäck criteria. Kruskal-Wallis analysis of variance (ANOVA) was used to evaluate the relationship between these two variables. RESULTS: The group classified as Ahlbäck grade V had significantly higher BMI than the others. CONCLUSION: There is a direct relationship between BMI and the degree of radiographic severity of gonarthrosis. Obesity appears to be directly related to the progression of knee osteoarthrosis.

OBJETIVO: Avaliar a relação do índice de massa corporal (IMC) do paciente com o grau de gravidade radiográfica da osteoartrose do joelho. MÉTODO: Foram avaliados, de forma prospectiva, 117 pacientes portadores de gonartrose. Os pacientes tiveram seus índices de massa corporal calculados e a artrose do joelho foi classificada segundo os critérios de Ahlbäck modificados. Usou-se a Anova de Kruskal­Wallis para avaliar a relação entre essas duas variáveis. RESULTADOS: O grupo classificado como grau V de Ahlbäck apresentou um IMC significativamente maior do que os demais. CONCLUSÃO: Existe relação direta entre o IMC e o grau de gravidade radiográfico da gonartrose. A obesidade parece estar diretamente relacionada à progressão da osteoartrose do joelho.

Anthropometric study of the knee and its correlation with the size of three implants available for arthroplasty.

OBJECTIVE: To define the anthropometric profile of the knee in a Brazilian population with gonarthrosis using intraoperative measurements; and to evaluate the compatibility of three implants available for total knee arthroplasty. METHODS: Morphometric data were collected prospectively from 117 subjects with gonarthrosis. Six dimensions in the distal femur and two in the proximal tibia were documented in 118 knees while performing total arthroplasty. These data were compared with the dimensions of three implants available for total knee arthroplasty. RESULTS: The statistical analysis showed that more than a quarter of the patients presented an unsatisfactory relationship between the knee and prosthesis. CONCLUSION: The implants evaluated need to be adjusted to better fit Brazilian patients.

OBJETIVO: Definir o perfil antropométrico do joelho em população brasileira portadora de gonartrose, com o uso da mensuração intraoperatória, e avaliar a compatibilidade de três implantes disponíveis para artroplastia total do joelho. MÉTODOS: Foram coletados, de forma prospectiva, os dados morfométricos de 117 pacientes portadores de gonartrose. Documentaram-se seis dimensões no fêmur distal e duas na tíbia proximal em 118 joelhos, durante a artroplastia total. Esses dados foram comparados com as dimensões dos três implantes disponíveis para artroplastia total do joelho. RESULTADOS: A análise estatística revelou que mais de um quarto dos pacientes apresentou relação inadequada entre os joelhos e as próteses. CONCLUSÃO: Os implantes avaliados necessitam de ajustes para melhor atender aos pacientes brasileiros.

Magnetic resonance study on the anatomical relationship between the posterior proximal region of the tibia and the popliteal artery.

OBJECTIVE: To analyze and describe the distance from the popliteal artery to three specific areas of the proximal region of the tibia, with the knee extended, by means of magnetic resonance. METHODS: Images of 100 knees of patients who underwent magnetic resonance examinations were analyzed. The location of the popliteal artery was measured in three different areas of the posterior proximal region of the tibia. The first measurement was made at the level of the knee joint (tibial plateau). The second was 9 mm distally to the tibial plateau. The third was at the level of the anterior tuberosity of the tibia (ATT). RESULTS: The distances between the popliteal artery and the tibial plateau and ATT region were significantly greater in males than in females. The distances between the popliteal artery and the regions 9 mm distally to the tibial plateau and the ATT were significantly greater in the age group over 36 years than in the group ≤36 years. CONCLUSION: Knowledge of the anatomical position of the popliteal artery, as demonstrated through magnetic resonance studies, is of great relevance in planning surgical procedures that involve the knee joint. In this manner, devastating iatrogenic injuries can be avoided, particularly in regions that are proximal to the tibial plateau and in young patients.

OBJETIVO: Analisar e descrever, com o joelho em extensão, a distância da artéria poplítea em três áreas específicas da região proximal da tíbia, por meio de ressonância magnética. MÉTODOS: Foram analisadas as imagens de 100 joelhos de pacientes submetidos a exame por ressonância magnética. A localização da artéria poplítea foi medida em três áreas distintas da região proximal posterior da tíbia. A primeira medida foi feita no nível da articulação do joelho (platô tibial). A segunda, a 9 mm distal do platô tibial. A terceira, ao nível da tuberosidade anterior da tíbia (TAT). RESULTADOS: As distâncias entre a artéria poplítea e o platô tibial e a região da TAT foram significativamente maiores no sexo masculino do que no feminino. As distâncias entre a artéria poplítea e a região 9 mm distal do platô tibial e a TAT foram significativamente maiores na faixa acima de 36 anos do que na faixa ≤ 36 anos. CONCLUSÃO: O conhecimento da posição anatômica da artéria poplítea, demonstrada por estudos de RM, é de grande relevância no planejamento de procedimentos cirúrgicos que envolvam a articulação do joelho. Com isso, podem-se evitar lesões iatrogênicas devastadoras, principalmente em regiões proximais ao platô tibial e em pacientes jovens.