Introduction:. Recent studies have concluded that gender influences hip morphology at the time of surgery as well as dysplastic development of the hip. This may lead to a particular choice of implant including stem design and/or neck modularity. In this study we hypothesized that not only gender but also morphotype and etiology (primary osteoarthritis versus aseptic osteonecrosis) may be a significant factor to predict the anatomy of the hip at the time of total hip arthroplasty (THA). Methods:. We reviewed 690 patients undergoing THA for primary arthritis (OA) or avascular osteonecrosis (AVN) between April 2000 and June 2005 and stratified each into three groups based on their anatomic constitution: endomorph (EN), ectomorph (ECT), or mesomorph (ME) (determined by the ratio: pelvic width/total leg length measured on full-length X-rays). Two independent observers measured twice four parameters on preoperative CT scan: neck-shaft-angle angle (NSA), femoral offset value (FO), helitorsion (Ht) value and femoral neck anteversion (Av). Results:. No significant difference were observed between men and women for the four parameters with respectively: NSA (129.29° ± 5.6 versus 129.3° ± 5.7), Av (20.3° ± 8.6 versus 20.27° ± 8.6), FO (19.7 mm ± 3.98 versus 19.74 mm ± 3.98) and Ht (19.97° ± 12.2 for men and 19.94° ± 12.3). Significant difference were found for NSA: 130.1° ± 5.8 for ECT, 129.55° ± 6 for MES and 128.2° ± 5,1 for EN with p < 0.01. For Av, the values were: 18.9° ± 8.7 for ECT, 20.74° ± 8.1 for MES and 21.2° ± 8.95 for EN (p < 0.01). For FO the values were 19.1 mm ± 3.9 for ECT, 19.7 ± 4 for MES and and 20.44 mm ± 3.93 for EN (p < 0.01). No difference was found for Ht between the 3 groups. A significant difference was found between patients suffering from OA and AVN: mean NSA was 130.36° ± 8.79 for OA patients versus 127.35° ± 8.38 for those who had an AVN (p < 0.01). A value was 17.06° ± 8.1 for OA and 23.7 ± 7.89 for AVN (p < 0.01). FO value was 18.72 mm ± 3.71 for OA versus 20.75 mm ± 4.15 for AVN (p <0.01). And Ht was 18.94° ± 9.64 for OA and 21.05° ± 14.5 for AVN patients (p < 0.01). Discussion and conclusion:. Patients with short and wide morphotype (endomorph) had, irrespective of gender, lower values of NSA with greater anterversion and offset values, whereas patients with long and narrow morphotype (ectomorph) had higher values of NSA and smaller Av and FO (figure 1). In the same time patients suffering from AVN have lower NSA angle, lower Av, smaller FO and Ht (figure 2). Femoral stem design should allow the consideration of these differences to optimize the reconstruction of the hip at the time of THA including pre-operative and intra-operative modularity

Introduction. The gold standard for knee surgery is the restoration of the so-called «neutral mechanical alignment ». Recent literature as pointed out the patients with «constitutional varus »; in these cases, restoring neutral alignment could be abnormal and even undesirable. The same situation can be observed in patients with «constitutional valgus alignment ». To date, these outliers cases have only been explored focusing on the lower limb; the influence of the pelvic morphotype has not been studied. Intuitively, the pelvic width could be a significant factor. The EOS low dose imaging technique provides full body standing X-rays to evaluate the global anatomy of the patient. This work explores the influence of the pelvic parameters on the frontal knee alignment. Material and methods. – We included 170 patients (340 lower extremities). 2 operators performed measurements once per patient on AP X-rays. The classical anatomical parameters were:. –. Femoral mechanical angle (FMA). –. Tibial mechanical angle (TMA). –. Hip knee shaft angle (HKS). –. Hip knee ankle angle (HKA). –. Femoral and tibial lengths. The morphotype was evaluated by:. –. the distances between the center of two femoral heads (FHD), between knees (KD) and between ankles (AD). –. the medial neck-shaft angle (MNSA). –. the femoral offset. The horizontal distance between the limb mechanical axis (line passing from center of the femoral head to the center of the ankle) and the center of the knee was called the intrinsic mechanical axis deviation (IMAD) (fig 1). The horizontal distance between the pelvic mechanical axis (line from the center of the sacral plate to the center of the ankle) and the center of the knee was called the global mechanical axis deviation (GMAD) (fig 2). Inter-Operator Reliability was calculated with Intra-class Correlation Coefficient (ICC) and Inter-Reader Agreement was assessed with Bland-Altman test. A relationship between IMAD and GMAD to the other parameters was assessed using Pearson's correlation coefficient. Results. Inter-Operator Reliability was high for femoral offset, TMA and MSNA (ICC > 0,88) and very high for the other parameters (ICC > 0,93). These values are given in table 1 and all the 2D parameters are given in the table 2. IMAD was significantly correlated with HKA (r = 0,99), FMA (r = −0,58), TMA (r = −0,61) and KD (r = 0,72). GMAD was significantly correlated with HKA (r = 0,94), FMA (r = −0,53), TMA (r = −0,60) and KD (r = 0,67). Two groups were identified according to pelvic width (FHD):. Group 1 (standard patients): Pelvic width < 18 cm (164 lower extremities). Group 2 (wide pelvis): Pelvic width ≥ 18 cm (176 lower extremities). For standard patients the FHD is a significant parameter, whereas the proximal femoral anatomy (offset and MNSA) are more relevant for wide pelvis. Conclusion. Accurate analysis of the morphotype of the lower limbs is essential for planning femoral or tibial osteotomy and knee prostheses. Taking into account pelvic morphotype can provide additional informations for the axes restoration and the detection of outliers patients

Background. The knee joint morphology varies according to gender and morphotype of the patients. Objectives. To measure the dimensions of the proximal tibia and distal femur of osteoarthritic knees in a group of patients from the same ethnic group (Arabs) and to compare these measurements with the dimensions of six total knee implants. Patients and methods. Three-dimensional CT reconstructions were used to collect morphologic data from 124 osteoarthritic knees. Anteroposterior and mediolateral measurements were obtained from tibial and femoral bony resection surfaces planned for patient-specific instrumentation (Figures 1 and 2). These measurements were compared to the dimensions for six different types of knee implants. Results. The average tibial mediolateral (tML) and tibial anteroposterior (tAP) measurement for the study group were 74.36±6 mm and 48.94±4.57 mm, respectively; the medial tibial plateau was larger than lateral. The average femur mediolateral (fML) and femur anteroposterior (fAP) measurements for the same group were 72.04±6.6 and 68.1±7.75, respectively. For implant matching, the average tibial aspect ratio was 152.62±12.66 and the femoral average aspect ratio was 106.37±14.34. Differences were found between morphometric measurements of males and females with significantly higher parameters for males when compared to female when compared in AP and mediolateral dimensions. Also, 22.5% of the operated knees had mismatch within 2 size of the same implant. Conclusion. There is significant asymmetry of proximal tibial plateau and femur condyles. Our data suggest mismatch between osteoarthritic Arabian knees and implant designs. These ethnic differences should be considered when designing knee implants

More than two thirds of TKA are performed on women. Most TKA systems are based on the male anatomy. Therefore one could ask if a women specific design is needed in Knee Arthroplasty. There are two distinct types of distal femur: the normal one and the narrow one. In the narrow femur the problem of overhang can occur because for a given AP dimension (sizing of the implant) the corresponding ML dimension is too large. Many years ago these findings were already published in different articles. It is only in recent years that interest came from the industry. In our department a study project was initiated in January 2006. This led to the development of the Stature Femoral component for the Advance Medial Pivot knee prosthesis. The first one was implanted in June 2007 and since then it is used in 60% of our female patients and 11% in our male patients. The reason why it is quite often used in male patients is because not only gender influences distal femoral geometry but also morphotype is an important factor. Therefore irrespective of gender, ectomorphs will have smaller ML ratios and thus will have smaller knees and will benefit from a Stature variant. Moreover we have seen that the correct use of the Stature variant can also influence our clinical scores and our percentages of ligament releases with overall better results