The iliopsoas is considered a major deforming force causing hip flexion deformity in children with cerebral palsy. Although iliopsoas release at the lesser trochanter is thought by many clinicians to cause excessive hip flexor weakness, we believe that it does not produce iatrogenic hip flexion weakness. We were unable to find a study in the literature that objectively studied this issue. Included in the study were 25 patients, all ambulators with cerebral palsy (any type). They underwent iliopsoas release at the lesser trochanter and multiple surgeries (soft tissue with or without bony procedures). Mean age at surgery was 11.4 years. Motion analysis was performed to all patients prior to surgery and one year post-op. Hip and knee range of motion was improved with out significant decrease in hip flexion power. Maximum hip extension improved, no change in maximum and total flexion power generation was found. As expected, hip range of motion was improved significantly. We proved that when releasing the iliopsoas at the lesser trochanter, the change in power generation is statistically insignificant, as shown by maximum and total hip power generation in swing phase

Purpose. Incidence of malrotation of femoral fractures after intramedullary nailing is as high as 28%. Prevention of malrotation is superior to late derotation osteotomy. The lesser trochanter (LT) profile has been in use for some time as a radiographic landmark of femoral rotation. One of the authors has previously described a linear regression model that describes the relationship of the LT to rotation. This paper aims to validate the use of this equation in predicting femoral rotation. Method. A survey was created and circulated online. Twenty images of cadaveric femurs of known rotation were chosen randomly from a large series. Thirty individuals with varying degrees of orthopaedic experience were invited to participate. Participants were asked to take measurements of the LT in a standardized fashion. Inter-observer variation for predicted rotation and the precision of predicted rotation was calculated. Results were grouped into those with the LT readily visible and those with the LT hidden by the femoral shaft. Results. A pilot study found the standard deviation for films with the LT hidden was 10.8 degrees, and only 6.0 degrees for films with the LT visible. The mean difference between the predicted and actual rotation was equally high in both groups (18.3 and 17.3 degrees respectively). Conclusion. Preliminary results found that the LT must be clearly visible to predict femoral rotation. This suggests that the surgeon should place the femur in a neutral or externally rotated position. In a favourable position most predictions were within a 6.0 degree spread, which would be sufficient to prevent a fifteen degree malrotation. Predicted rotation was however not precise enough to prevent a fifteen degree malrotation, regardless of LT visibility. The precision of predicted rotation may be improved by using a non-linear model. Such a model has recently been designed by a group of engineers at the University of Manitoba. The r squared value of the non-linear model was 0.88, in comparison to 0.78 for the linear equation. Precision may be further improved by using the contra-lateral LT for comparison

Aims. This study aimed to investigate the incidence of ≥ 5 mm asymmetry in lower and whole leg lengths (LLs) in patients with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH-OA) and primary hip osteoarthritis (PHOA), and the relationship between lower and whole LL asymmetries and femoral length asymmetry. Methods. In total, 116 patients who underwent unilateral total hip arthroplasty were included in this study. Of these, 93 had DDH-OA and 23 had PHOA. Patients with DDH-OA were categorized into three groups: Crowe grade I, II/III, and IV. Anatomical femoral length, femoral length greater trochanter (GT), femoral length lesser trochanter (LT), tibial length, foot height, lower LL, and whole LL were evaluated using preoperative CT data of the whole leg in the supine position. Asymmetry was evaluated in the Crowe I, II/III, IV, and PHOA groups. Results. The incidences of whole and lower LL asymmetries were 40%, 62.5%, 66.7%, and 26.1%, and 21.7%, 20.8%, 55.6%, and 8.7% in the Crowe I, II/III, and IV, and PHOA groups, respectively. The incidence of tibial length asymmetry was significantly higher in the Crowe IV group (44.4%) than that in the PHOA group (4.4%). In all, 50% of patients with DDH-OA with femoral length GT and LT asymmetries had lower LL asymmetry, and 75% had whole LL asymmetry. The incidences of lower and whole LL asymmetries were 20% and 42.9%, respectively, even in the absence of femoral length GT and LT asymmetries. Conclusion. Overall, 43% of patients with unilateral DDH-OA without femoral length asymmetry had whole LL asymmetry of ≥ 5 mm. Thus, both the femur length and whole LL should be measured to accurately assess LL discrepancy in patients with unilateral DDH-OA. Cite this article: Bone Jt Open 2024;5(2):79–86

Aims. The aim of this study was to report the long-term follow-up of cemented short Exeter femoral components when used in primary total hip arthroplasty (THA). Methods. We included all primary 394 THAs with a cemented short Exeter femoral component (≤ 125 mm) used in our tertiary referral centre between October 1993 and December 2021. A total of 83 patients (21%) were male. The median age of the patients at the time of surgery was 42 years (interquartile range (IQR) 30 to 55). The main indication for THA was a childhood hip disease (202; 51%). The median follow-up was 6.7 years (IQR 3.1 to 11.0). Kaplan-Meier survival analyses were performed to determine the rates of survival with femoral revision for any indication, for septic loosening, for fracture of the femoral component and for aseptic loosening as endpoints. The indications for revision were evaluated. Fractures of the femoral component were described in detail. Results. The 20-year rate of survival was 85.4% (95% confidence interval (CI) 73.9 to 92.0) with revision for any indication, 96.2% (95% CI 90.5 to 98.5) with revision for septic loosening and 92.7% (95% CI 78.5 to 97.6) with revision for fracture of the femoral component. No femoral components were revised for aseptic loosening. There were 21 revisions of the femoral component; most (seven) as part of a two-stage management of infection. Fracture of the femoral component occurred in four THAs (1.0%) at 6.6, 11.6, 16.5, and 18.2 years of follow-up, respectively. Three of these were transverse fractures and occurred at the level of the lesser trochanter. In one THA, there was a fracture of the neck of the component. Conclusion. THAs using cemented short Exeter femoral components showed acceptable rates of survival of the femoral component at long-term follow-up, in this young cohort of patients. Although fracture is a rare complication of these components, surgeons should be aware of their incidence and possible risk factors. Cite this article: Bone Joint J 2024;106-B(3 Supple A):137–142

Aims

This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.

Securing the osteotomized greater trochanter (GT) during total hip arthroplasty (THA) for dislocated dysplastic hips (DDH) poses a significant challenge. This study evaluates the union rate and effectiveness of a 2-strand transverse wiring technique utilizing the lesser trochanter for wire anchorage and tensioning. A digastric anterior slide trochanteric osteotomy was performed in 106 patients (118 hips) undergoing THA for DDH. Following uncemented stem insertion, the GT was transferred and fixed to the lateral cortex of the proximal femur using monofilament stainless steel wires. In 72 out of 106 patients (80 hips), the GT was fixed with 2 transverse wire cerclages threaded through 2 drill holes in the base of the lesser trochanter, spaced vertically 5–10 millimeters apart. The wires were wrapped transversely over the GT and tightened, avoiding contact with its tendinous attachments. Patients were regularly monitored, and GT union was assessed clinically and radiographically. Patient ages ranged from 20 to 57 years (mean 35.5), with a follow-up period ranging from 1.5 to 12 years (mean 6.2). The mean union time was 3.3 months (range 2–7). Among all hips, two developed stable nonunion and single wire breakage, but no fragment displacement (2.5%). Two hips exhibited delayed union, eventually healing at 6 and 7 months after surgery. Reattachment of the greater trochanter utilizing a 2-strand transverse wire cerclage anchored at the base of the lesser trochanter demonstrated a high rate of union (97.5%) following THA in dislocated DDH cases

Aims. The aim of this study was to examine whether hips with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH) have significant asymmetry in femoral length, and to determine potential related factors. Patients and Methods. We enrolled 90 patients (82 female, eight male) with DDH showing unilateral OA changes, and 43 healthy volunteers (26 female, 17 male) as controls. The mean age was 61.8 years (39 to 93) for the DDH groups, and 71.2 years (57 to 84) for the control group. Using a CT-based coordinate measurement system, we evaluated the following vertical distances: top of the greater trochanter to the knee centre (femoral length GT), most medial prominence of the lesser trochanter to the knee centre (femoral length LT), and top of the greater trochanter to the medial prominence of the lesser trochanter (intertrochanteric distance), along with assessments of femoral neck anteversion and neck shaft angle. Results. The percentages of hips with an absolute difference of > 5 mm in femoral GT and LT lengths were significantly larger in the DDH group (24% for both) compared with those of the control group (2% and 7%, respectively). The femoral length GT of the affected femur was significantly shorter in Crowe I and longer in Crowe IV than that of the unaffected side. The affected-to-unaffected difference of the intertrochanteric distance showed positive correlation with that of the femoral length GT in Crowe I and Crowe II/III, and negative correlation with that of the femoral length LT in the Crowe I and Crowe IV groups. Conclusion. Hips with unilateral end-stage OA secondary to DDH show significant asymmetry in femoral length between both the greater and lesser trochanter and the knee compared with controls. The intertrochanteric distance was a morphological factor related to femoral-length asymmetry. When undertaking total hip arthroplasty (THA) in the presence of DDH, long leg radiographs or CT measurements should be used to assess true leg-length discrepancy. Cite this article: Bone Joint J 2019;101-B:297–302

Objective. In total hip arthroplasty (THA), the femoral component influences leg length inequality and gait, and is associated with poor muscle strength and other unsatisfactory long-term results. We have therefore used intraoperative radiographs to acquire accurate measurements of femoral component size and position. At the last meeting of this society, we reported that accurate positioning was successfully achieved in 68 cases (87.2%) as a consequence of taking intraoperative radiographs. However, we have little understanding as regards to the accuracy of X-ray measurements. We accordingly undertook an examination of the accuracy of such measurements. The purpose of this study was to evaluate the difference between leg length discrepancy (LLD) measured using X-ray and computed tomography (CT). Materials and Methods. The study group comprised 48 primary THAs performed between October 2010 and April 2012. Using 2D template software (JMM Corporation), we measured LLD using pre-operative anteroposterior (AP) radiographs of the pelvis. On the basis of both teardrop lines, we measured LLD of the lesser trochanter top (Fig. 1), lesser trochanter direct top (Fig. 2), and trochanteric top (Fig. 3). Furthermore, using Aquarius NET software, we measured LLD using AP and lateral scout views of the pelvis and bilateral femurs. This data was defined as the true LLD. The difference between the X-ray data (lesser trochanter top, lesser trochanter direct top, and trochanteric top) and the CT data was defined as accuracy. Additionally, we measured the size of the lesser trochanter and examined the association. Results. The mean LLD was 11.4, 12.1, and 9.6 mm on the lesser trochanter top, the lesser trochanter direct top, and the trochanteric top of radiographs, respectively, and 11.6 mm on CT scans. Precision was within 5 mm of the true LLD in 42 cases (87.5%) for the lesser trochanter top, 36 cases (75.0 %) for the lesser trochanter direct top, and 27 cases (63.0%) for the trochanteric top. We observed no association between the size of the lesser trochanter and the measurement accuracy. Conclusions. When using X-ray measurements, the lesser trochanter top is the most useful site for LLD measurement

One of the most important characteristic of the developmental dysplastic hip (DDH) is high anteversion in femoral neck. Neck-shaft angle is also understood to be higher (i.e. coxa-valga) in DDH femora. From this understanding many DDH intended stems were designed having larger neck shaft angle. According to the result of our prior study; reported in ISTA 2005 etc.; using computer 3-D virtual surgery of high fit-and-fill lateral flare stem into high anteversion patients, it was revealed that the geometry of proximal femur itself does not have big difference from normal femora but they are only rotated blow lessertrochanter. It is very important to know what anteversion is, and where anteversion is located, to design a better stem and to decide more proper surgical procedures for DDH cases with high anteversion. In the present study, the geometry of 57 femora was assessed in detail to reveal the geometry of anteversion and its location in the DDH femora. Fifty seven CAT scan data with many causes were analyzed. Thirty-two DDH, 3 Rheumatic Arthritis (RA), 2 metastatic bone tumors, 4 avascular necrosis (AVN), 1 knee arthritis, 12 injuries, and 3 normal candidates were included. Whole femoral geometries were obtained from CAT scan DICOM data and transferred to CAD geometry data format. All the following landmarks were measured its direction by the angle from posterior condylar line. The assessed landmarks were. anteversion,. lesser trochanter,. linea aspera at the middle of the femur, and two more (upper 1/6, 2/6 level of aspera) linea aspera directions were assessed between ii) and iii). All the directions were measured by the angle from the medial of the femur. The direction of anteversion and lesser trochanter were well correlated, (R=0.55, Y=0.56X−35) i.e. femoral head and lesser trochanter were rotated together. The direction of lesser trochanter and aspera in upper 1/6 section had no relation even they are located very close with only several cm distance, (R=−0.03, Y=−0.02X−88) i.e. however the lesser trochanter was rotated, the upper most aspera was located almost at the same direction (−87.5+/−7.58 degree). The direction of aspera at upper 1/6 and middle femur were strongly correlated. (R=0.63, Y=0.81X-22) i.e. they stay at the same direction. The results mean that the anteversion is a twist between normal proximal femur (from femoral head and lesser trochanter) and normal distal femur. The twist was located just blow lesser trochanter within several centimeter. The anteversion has been understood as the abnormal mutual position between femoral neck and femoral shaft. In high anteversion hips the neck shaft angle was also believed to be higher, so several DDH oriented stems have higher neck shaft angle i.e. coxa-valga geometries. It has been believed that the location of the anteversion was around neck part. This study revealed that the deformity was located in the very narrow part just below lesser trochanter. It has been discussed that DDH oriented stems should have fit to different canal geometries, but understanding the biomechanics of abnormal anteversion and its treatment should be more important

Purpose. Leg length discrepancy after total hip arthroplasty (THA) sometimes causes significant patient dissatisfaction. In consideration of the leg length after THA, leg length discrepancy is often measured using anteroposterior (AP) pelvic radiography. However, some cases have discrepancies in femoral and tibial lengths, and we believe that in some cases, true leg length differences should be taken into consideration in total leg length measurement. We report the lengths of the lower limb, femur, and tibia measured using the preoperative standing AP full-leg radiographs of the patients who underwent THA. Materials and methods. From August 2013 to February 2017, 282 patients underwent standing AP full-leg radiography before THA. Of the patients, 33 were male and 249 were female. The mean age of the patients was 65.7±9.4 years. We measured the distances between the center of the tibial plafond and lesser trochanter apex (A-L), between the femoral intercondylar notch and lesser trochanter (K-L), and between the centers of the tibial plafond and intercondylar spine of the tibia (A-K) on standing AP full-leg radiographs before THA operation. We examined the differences in leg length and the causes of these discrepancies after guiding the difference between them. Results. The mean A-L was 674±44 mm on the right and 677±43 mm on the left. The mean difference between the left and the right was 6.2±7 mm. The differences of ≥5 and ≥10 mm between the left and right were confirmed in 131 (46%) and 39 cases (14%), respectively. The mean K-L was 343±23 mm on the right and 343±23 mm on the left, with a mean difference of 4.4±4 mm. The lateral differences of ≥5 and ≥10 mm were confirmed in 88 (31%) and 22 (8%), respectively. The mean A-K was 325±22 mm on the right and 327±22 mm on the left, with a mean difference of 4±4.5 mm. The differences of ≥5 and ≥10 mm between the left and right were confirmed in 24 (9%) and 67 cases (%), respectively. Discussion. Considering the total length of the lower limbs beyond the little trochanter and the leg length after THA, we confirmed that 46% of the leg length differences of ≥5 mm were admitted to 14%. Thus, THA appeared effective. Perthes head, Crowe classifications 3 and 4, history of childhood paralysis, and so on may be factors for leg length differences beyond the lesser trochanter. Conclusion. We think that it would be preferable to prepare a preoperative plan to measure leg length after THA by measuring the total length of the lower extremity before surgery and determining the difference between the left and right sides

Objective: Establishment of the new method to evaluate fill of the hip stem. Background: The fill of the hip stem is one of the important parameters to estimate the quality of planning or positioning of the cementless stem. It has been defined as a stem-canal width ratio on the A-P plain of X-ray images so far. However, it is quite a problem to get the correct AP images on basis so that positional difference may affect the measurement. According to our data, the fill was measured significantly different in 15, 30, 45, 60 degrees erroneous direction. First, we tried to figure out the fill of the hip stem three-dimensionally rather 2-dimensionally. Next, our new method was compared to conventional method. Material and Methods: Leg CAT scans were performed on 32 hips of 20 patients (2 male, 18 female). Images of the canal of femora were reconstructed using CAD software. We made 2-types of canal model with or without lesser trochanter. The geometries of our lateral flare stems with different sizes were compared to each canal geometry in the CAD software and proper size was decided. Then images were observed from an accurate vertical direction of the coronal plain of the stem. We measured the 2-D fill on this plane and the 3-D fill of every 5 mm slice from the 5mm above to the 100mm below the head of lesser trochanter line (reference line). We also examined the stems 1-size smaller or larger than the appropriate ones. Results: The mean age was 61.114 (range 24–82). The average of “3-D fill of Lateral flare stem was 51%/59% with/without lesser trochanter, and 2-D one was 74%/77%. The numerical and distributional results by these two methods to measure fill were alike but different. For example, in case without lesser trochanter, the 3-D fill showed the maximum value in the area just below the reference line. The maximum 2-D fill was recorded in 10mm caudal from the reference line. In general, this stem occupied much space in the distal area and around the lesser trochanter. Future Plan: Extension of this evaluation method into various kinds of stems

Introduction: Clinical experience has shown that addressing variations in bone morphology is important in the development of successful hip implant designs. Numerous studies of femoral bone morphology have been published utilizing various techniques. This study has developed a method which consistently measures large quantities of 3-dimensional digital femura geometry segmented from computed tomography (CT) scans and can accurately make anatomical measurements from these images. Methods: CT images of left femora on five hundred fifty six left femura (57% male, 43% female), consisting of 69% Caucasian, 16% Asian and 14% unknown were analyzed. The average age was 66 years, ranging from 40 to 93 years. Segmentation of the outer cortical, inner cortical, and marrow boundaries were consistently performed over all CT scans. The positions identified on the reference bone are transformed to the equivalent position on the clinical bone images, from which the dimensional data is extracted and stored. The mediolateral width (MLW), medial offset (MO) and lateral offset (LO) were measured in 10mm increments, ranging from 20mm above the lesser trochanter (LT) to 130mm below the lesser trochanter. The canal flare index was defined as a ratio of the mediolateral width at a section 20mm above the lesser trochanter to the mediolateral width at the isthmus level. Results: The mean mediolateral width at 20mm above the lesser trochanter was 47.0 ± 4.5 (35.1–61.8; n=556). Noble reported 45.4 ± 5.3 (31.0–60.0; n=200), Husmann reported in a neck oriented study 46.3 ± 6.9 (27.6–63.6; n=310) and Laine reported 47.1 ± 4.9 (n=50). The mean medial offset at a section 20mm above the lesser trochanter was 25.1 ± 2.9 (16.7–33.4). In the study by Husmann, a mean of 25.0 ± 5.2 (9.4–45.5) was reported. The mean canal flare index was 4.49 ±.8. Noble reported a mean canal flare index of 3.80 ±.074, Husmann 3.81 ±.83 and Laine 4.3 ±.93. Discussion: In general, the study showed minor differences to published data of proximal bone morphology. However, this more powerful study has shown that there is a higher mean canal flare index than determined by Noble and a similar mean canal flare index as determined by Laine. As reported by Laine, the canal flare index varies significantly with the placement of measurements in the canal. In this study the measurements were performed in a plane oriented by the femoral neck as a hip stem would be placed. The CFI over the isthmus width showed a greater correlation than previously shown by Noble. The novel software tool allows for anatomical measurements that can be applied to an unlimited population size enabling further applications and studies

Purpose. Accolade TMZF® has the wedged taper shape and is fixed at the middle part. We testified the short term result of Accolade® and investigated the factor of subsidence. Materials and Methods. We treated 21 hips in 20 patients (6 males and 15 females) with Accolade stem. The mean age was 61.2 years old (40–79 years old). The mean follow-up period was 11.1 months (6–23 months), and those within 5 months after operation were excluded. We measured the width of the stem and the canal of femur at the level of the upper and the lower end of lesser trochanter, and 1 cm above the tip of the stem at operation and at the last follow-up, then calculated the canal fill ratios. We also measured the distance between the tip of the stem and the proximal end of greater trochanter, then calibrated it by directly sizing the acetabular component. The value that subtracted the distance at the last follow-up from the distance at operation meant subsidence. We performed multiple regression study about weight and the canal fill ratio of stem at the level of lower end of lesser trochanter. Results. The mean subsidence of the stem was 1.24 mm (0∼4.50 mm). The patients with 2 mm or more subsidence were four, and the patients with 1 mm or less subsidence were ten. There were no significant differences in weight and the canal fill ratio at the level of lower end of lesser trochanter, but the canal fill ratio of the stem tended to negatively correlate with subsidence. Discussions and conclusions. Some authors reported the most important factors in predicting a failure of osteointegration were canal fill at the mid-third of the stem, canal fill at the distal-third of the stem, and canal flare index. Others reported large stem size was associated with subsidence. Our result showed the canal fill ratio at the level of lower end of lesser trochanter is associated with subsidence. Besides, Accolade® tended to result in more severe resorption of the proximal femur and lack of osteointegration. Accolade® had a good result in the short term evaluation, but we should observe the subsidence carefully because the proximal femur cortex inclines to resorption and the osteointegration doesn't ocuur

Aims. The diversity of femoral morphology renders femoral component sizing in total hip arthroplasty (THA) challenging. We aimed to determine whether femoral morphology and femoral component filling influence early clinical and radiological outcomes following THA using fully hydroxyapatite (HA)-coated femoral components. Methods. We retrospectively reviewed records of 183 primary uncemented THAs. Femoral morphology, including Dorr classification, canal bone ratio (CBR), canal flare index (CFI), and canal-calcar ratio (CCR), were calculated on preoperative radiographs. The canal fill ratio (CFR) was calculated at different levels relative to the lesser trochanter (LT) using immediate postoperative radiographs: P1, 2 cm above LT; P2, at LT; P3, 2 cm below LT; and D1, 7 cm below LT. At two years, radiological femoral component osseointegration was evaluated using the Engh score, and hip function using the Postel Merle d’Aubigné (PMA) and Oxford Hip Score (OHS). Results. CFR was moderately correlated with CCR at P1 (r = 0.44; p < 0.001), P2 (r = 0.53; p < 0.001), and CFI at P1 (r = − 0.56; p < 0.001). Absence of spot welds (n = 3, 2%) was associated with lower CCR (p = 0.049), greater CFI (p = 0.017), and lower CFR at P3 (p = 0.015). Migration (n = 9, 7%) was associated with lower CFR at P2 (p = 0.028) and P3 (p = 0.007). Varus malalignment (n = 7, 5%), predominantly in Dorr A femurs (p = 0.028), was associated with lower CFR at all levels (p < 0.05). Absence of spot welds was associated with lower PMA gait (p = 0.012) and migration with worse OHS (p = 0.032). Conclusion. This study revealed that femurs with insufficient proximal filling tend to have less favourable radiological outcomes following uncemented THA using a fully HA-coated double-tapered femoral component. Cite this article: Bone Joint Res. 2020;9(4):182–191

I use monolithic, cylindrical, fully porous coated femoral components for many femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been re-revised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral re-revision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Aims. A lack of supporting clinical studies have been published to determine the ideal length of intramedullary nail in fixation of trochanteric fractures of the hip. Nevertheless, there has been a trend to use shorter intramedullary nails for the internal fixation of trochanteric hip fractures. Our aim was to determine if the length of nail affected the outcome. Methods. We randomized 229 patients with a trochanteric hip fracture between two implants: a ‘standard’ nail of 220 mm and a shorter nail of 175 mm, which had decreased proximal angulation (4° vs 7°) and a reduced diameter at the level of the lesser trochanter. Patients were followed up for one year by a nurse blinded to the type of implant used to determine if there were differences in mobility and pain with two nail designs. Pain was assessed on a scale of 1 (none) to 8 (severe and constant) and mobility on a scale of 1 (full mobility) to 9 (immobile). Results. The shorter nail did not require any reaming of the femur and was quicker to insert (mean difference 5.1 minutes; p < 0.001, 95% confidence interval (CI) of the difference 3.16 to 7.04). Those treated by the shorter nail were less mobile (mean difference in reduction in mobility score at one year 0.80; p = 0.007, 95% CI 1.38 to 0.22). In addition, there was a trend toward greater residual pain for those treated with the shorter nail, although this was not statistically significant (mean difference in pain score at one year 0.24; p = 0.064, 95% CI -0.01 to 0.49). Conclusion. These results suggest that the increasing use of this very short intramedullary nail with its design modification may not be appropriate. Cite this article: Bone Joint J 2020;102-B(3):394–399

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10cm below the lesser trochanter, and 12% had cortical damage that extended more than 10cm below the lesser trochanter. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10-inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Summary Statement. We used three-dimensional software to assess different anatomic variables in the femur. The canal of Femur twisted slightly below the lesser trochanter in cases with a larger angle of anteversion. Introduction. Accurate positioning of the joint prosthesis is essential for successful total hip arthroplasty (THA). To aid in tailoring of the prosthesis, we used three-dimensional software to assess different anatomic variables in the femur. Patients & Methods. We used CT imaging data of the unaffected normal side of the 25 patients (22 females, age range 30 to 81 years) who underwent THA in 2012 in our hospital. The femur was reconstructed from CT data and measured using three-dimensional modeling software (Mimics 16.0 Materialise, Leuven, Belgium). We measured ellipse fitting to the medullary canal in the axial plane of the femur at 20-mm intervals. The angle between the major axis of those ellipses and the axis of the femoral neck was measured and expressed as the canal rotation. The distance between the lesser trochanter and the center of the femoral head was measured along the Z axis. Results. The major axes of the ellipses direct to medial, front and medial side in the level of epiphysis, above isthmus and distal portion respectively in all cases. The maximum rotated level was above isthmus. The rotation angle in the proximal portion ranged from 36 to 84 degrees (mean, 60.6 degrees, SD ± 12.1). The rotation angle of the distal portion ranged from 71 to 95 degrees (mean, 86.1 degrees, SD ± 6.1). Discussion/Conclusion. The torsion of the canal varied more widely between individuals in the proximal portion than did the distal portion. In addition, the torsion of the proximal aspect, although more variable, was on average smaller when the angle of anteversion was large. Because the canal twisted slightly below the lesser trochanter in cases with a larger angle of anteversion, it is suggested that attention to the degree of anteversion of a flat prosthesis stem is warranted

Introduction. In DDH cases often have high anteversion. They also often have high hip center. THA for those cases sometimes requires subtrochanteric derotational/shortening osteotomy. To achieve good results of the surgery, accurate preoperative planning based on biomechanics of the high anteversion cases, method for accurate application of the plan, and stable fixation are very important. At ISTA 2008, we have reported that the location of the anteversion exist several centimeters below the lesser trochanter. Independently from the extent of anteversion, femoral head, grater trochanter, and lesser trochanter are aligned in the same proportion. We have also reported in 2007, in improper high anteversion cases, many cases grow osteophytes posterior side of femoral head to reduce it functionally. In 2014, we reported about development of the stem for subtrochanteric osteotomy. (ModulusR)[Fig.1] In the present study, we established systematic planning way for estimate proper derotation and shortening and apply it for the surgery. Methods. Leg alignment during walking were well observed. According to the CT, 3D geometry of the femur, anteversion in hip joint and its compensation by the osteophyte, and knee rotation were measured. It was divided into proximal part and distal part at several centimeter below the lesser trochanter. Adequate hip local anteversion was determined by local original anteversion – compensation if IR-ER can be done. Keeping that anteversion for the proximal part, distal part was rotated as knee towards front. Thus derotation angle was decided. Using 3D CAD (Magics®) proper size of Modulus R was selected and overlapping with canal was extracted then its center of gravity was calculated. This level is decided as the height of osteotomy to obtain equal fixation to both proximal and distal part.[Fig.2] If the derotation angle is less than 15 degree, modular neck adjustment was selected first. By trial reduction and motion test, according to the instability osteotomy was performed. In the high hip center cases, original hip center was reconstructed. Shortening length was determined not to make leg elongation more than 3cm. ModulusR were used for the replacement and fixation of the osteotomy. Results. Eight cases were operated with this procedures. Standard Modulus was used in one case. In the case rotational fixation was well obtained but proximal stress shielding happened. ModulusR was used in other seven cases. In one ModulusR case vertical clack; which was fixed by metal band; happened in proximal part by the repeated rotational adjustment. But in all ModulusR cases, weight baring could be started in 1 week and good union was observed. Every patient feels knee direction became better than before.[Fig.3,4]. Discussion. In intraoperative stability test, much better stability was obtained after derotational osteotomy was done than the adjustment only by modular neck direction. Reducing anteversion by osteotomy was supposed to have advantage. Limitation of this paper is that the adequate hip local anteversion was estimated from femoral geometry and osteophytes and knee direction during walking. Future improvement would to use 2D-3D matching while walking to determine accurate hip local anteversion

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Purpose of the study: Transadductor approaches to the hip joint have been described in the spastic child. Ludl-off as well as Ferguson pass behind the short adductor and the pectineus, a narrow route with a risk of injuring the obturator nerve. We describe a simple minimally invasive approach. Material and method: The incision is made with the hip in the flexion, external rotation, abduction, from the pubic insertion of the long adductor following along the mass of the muscle for 6 to 8 cm. The aponeurosis of the long adductor is cut just deep enough to see the muscle fibres. Careful finger dissection of the muscle sheath common to the three anterior adductor muscles leads directly to the lesser trochanter. Two forceps are inserted on either side of the lesser trochanter, exposing the lesser trochanter and the tendon of the iliopsoas muscle. Dissection of the iliopsoas muscle held aside (follow the tendon on its lateral aspect leading to the vessels). An angled spreader is positioned between the anterior aspect of the capsule and the medial border of the tendon, displacing the tendon laterally and exposing the capsule. Extra-articular exposure of the capsule with a rugine to displace the posterior medial circumflex pedicle. Longitudinal incision of the capsule continued along the inter-trochanteric line to the peri-acetabular region. The medial as well as the anterior aspect of the neck can be visualized by rotating the hip. The inferior and anterior portion of the head is visible: the iliopubic branch and the entire superior and medial wall of the acetabulum can be exposed. Results: We performed 29 medial approaches. Nine for periprostheic pain, four for fresh fracture of the femoral head during posterior dislocation, four for old fractures of the femoral head during posterior dislocation, three for chondromatosis, three for tumours of the femoral head or the acetabulum, six for retractile periarthritis without arthroplasty. Hip arthroplasty (7) or not (6), median pain could be induced by the presence of retractile periarthritis with presence of synovial adherences to the femoral neck penetrating into the joint space; release relieved pain in 11/13. Conclusion: The medial approach to the hip joint is a useful orthopaedic technique with a rapid learning curve

Background: To highlight the higher incidence of sub-trochanteric fracture following cannulated screws fixation for the neck of femur fracture, which may be due to surgical errors and osteoporotic bone. Method: Illustrative case report of a 78 years old demented independently mobile female patient who was admitted with an intracapsular Neck of Femur fracture, treated with cannulated screws. 2 weeks post operatively, she developed subtrochanteric undisplaced proximal femoral fracture without any trauma. She was treated with cemented hemiarthroplasty. Conclusion: The valgus impacted neck of femur fracture, treated with cannulated screws is associated with some inherent problems. The cannulated screws can become incarcerated during initial open-reduction internal fixation and break. The incidence of subtrochanteric fracture following hip operation is greater with an entry point in the lateral cortex below the level of the most inferior edge of the lesser trochanter. Although in our case study, we placed the screw above the lesser trochanter. It has been reported that two screws in the inferior part of the femoral neck create a stress riser in the sub-trochanteric region, potentially inducing a fracture in the weakened bone, and it may be induced by a trauma. In this case study failure may be due to multiple drill holes on the lateral cortex during insertion of the guide wire [fig 2]. Subtrochanteric fracture following cannulated screws may occur without trauma. Osteoporosis may have a major role to play. We recommend one screw infe-riorioly and entry point above the lesser trochanter as reported previously

Abstract. Objectives. Stem malalignment in total hip arthroplasty (THA) has been associated with poor long-term outcomes and increased complications (e.g. periprosthetic femoral fractures). Our understanding of the biomechanical impact of stem alignment in cemented and uncemented THA is still limited. This study aimed to investigate the effect of stem fixation method, stem positioning, and compromised bone stock in THA. Methods. Validated FE models of cemented (C-stem – stainless steel) and uncemented (Corail – titanium) THA were developed to match corresponding experimental model datasets; concordance correlation agreement of 0.78 & 0.88 for cemented & uncemented respectively. Comparison of the aforementioned stems was carried out reflecting decisions made in the current clinical practice. FE models of the implant positioned in varus, valgus, and neutral alignment were then developed and altered to represent five different bone defects according to the Paprosky classification (Type I – Type IIIb). Strain was measured on the femur at 0mm (B1), 40mm (B2), and 80mm (B3) from the lesser trochanter. Results. Cemented constructs had lower strain on the implant neck, and higher overall stiffness and strain on bone compared to uncemented THA. Strain on the bone increased further down the shaft of the femoral diaphysis, and with progressing bone defect severity in all stem alignment cases. Highest strain on the femur was found at B2 in all stem alignment and bone defect models. Varus alignment showed higher overall femoral strain in both fixation methods. Interestingly, in uncemented models, highest strain was shown on femoral bone proximally (B1-B2) in varus alignment, but distally (B3) in neutral alignment. Conclusion. Varus stem alignment showed overall higher strain on femur compared to neutral and valgus. This highlights the crucial role of stem alignment in long term outcomes of THA. Differences between the two stem types should be taken in consideration when interpreting results from this study

Introduction: A major concern with cemented hip resurfacing arthroplasty (HRA) femoral components is the thermal damage to femoral head during cement curing; this maybe linked to fracture (reported incidence ~2%) and early failure. We investigated the effect of a modifid surgical technique using pulse lavage, lesser trochanter suction and early reduction on the maximum temperature recorded in the femoral head during HRA, compared to manual lavage and reduction after cement curing. Methods: Patients undergoing total hip replacement (THR) were given a dummy HRA procedure, during which a temperature probe was inserted into the femoral head and the measuring tip placed close to the reamed surface; the position of the probe was confirmed by inter-operative xray. Four subjects received a dummy HRA femoral component using manual lavage and Simplex cement. The implanted femur was kept dislocated until the cement cured. The implanted heads were then removed and sectioned to locate the temperature probes, the THR surgery was then performed. Five patients receiving a definitive HRA were also measured; for these subjects suction on the lesser trochanter was used, pulse lavage given for 30 seconds prior to cementing with Simplex, and pulse lavage of the femoral head for 2 minutes, applied 1 minute after cementing the femoral component. The implanted joint was then immediately reduced and a further two minutes of pulse lavage applied to the reduced joint. Temperatures were recorded until the cement finally cured. In every case the cement was hand mixed for 1 minute and the component implanted at 2 minutes 30 seconds after mixing began. Results: Sectioning showed that probe tips were < 0.5mm from cement mantle. The maximum temperature recorded in the femoral head was significantly (p=0.014) greater for the manual technique, median value of 47.2°C (37.0 to 67.9°C), than for the pulse lavage technique, median value of 32.7°C (31.7 to 35.6°C). Discussion: The results show that excessive bone temperatures can occur during hip resurfacing. Temperatures above 45°C kill bone cells, the manual technique may lead to substantial thermal necrosis. Technique modification, with the use of suction on the lesser trochanter, generous use of pulse-lavage and joint reduction prior to cement curing, significantly reduced the temperatures recorded. With the modified technique, the maximum temperatures were well below the threshold of thermal damage. This modified technique is recommended as the potential for thermal bone necrosis is significantly reduced

Limb length discrepancy (LLD) is a complication of total hip arthroplasty (THR). We reviewed the x-rays of patients who underwent THR in our unit to establish the incidence and magnitude of LLD, and try to identify reasons why a length discrepancy arose. Patients with abnormalities of the opposite hip (previous THR, significant osteoarthritis) were excluded, to allow comparison with a normal contralateral side. 100 consecutive patients who fulfilled these criteria were included. There were 38 male and 62 female patients. The implants used were Charnley (89 cases), Elite (4 cases), and Exeter (7 cases). The following measurements were made on pre-and post-operative films on the hospital PACS system: centre of lesser trochanter to ischial tuberosity; tip of greater trochanter to centre of femoral head; centre of head to base of teardrop. The distance from the osteotomy in the femoral neck to the centre of the lesser trochanter was also measured. The interval from the greater trochanter to the closest margin of the pelvis, and the interval from the lesser trochanter to the base of the teardrop (compared to the normal side) were recorded as indices on adduction. Surgery was performed via a direct lateral (Hardinge) approach (95 cases) or through transtrochanteric approach (5 cases). There was a radiographic difference between limbs of > 1cm in 43 cases; in 9 of these, the operated limb was longer, and in 34 cases it was shortened. In those cases where the operated side was lengthened, the cause was on the acetabular side in 2 patients, and on the femoral side in 25 cases, and on the femoral side in 9 cases. The shortened limb was noted to be adducted relative to the opposite side in 29 patients. There was difference noted in the incidence of discrepancy between different implants. The transtrochanteric approach was associated with significantly (p< 0.01) less length discrepancy. Our findings suggest that shortening is much more common than lengthening following THR, and that incorrect positioning of the acetabulum is the more likely cause. Persistence of an adduction contracture may also contribute to an apparent shortening postoperatively. The transtrochanteric approach appeared to make LLD less likely. Surgeons should be aware of these findings when performing THR. The clinical effect of differing degrees of LLD is till debatable

Femoroacetabular impingement is a well-documented cause of hip pain. There is, however, increasing evidence for the presence of a previously unrecognised impingement-type condition around the hip – ischiofemoral impingement. This is caused by abnormal contact between the lesser trochanter of the femur and the ischium, and presents as atypical groin and/or posterior buttock pain. The symptoms are gradual in onset and may be similar to those of iliopsoas tendonitis, hamstring injury or bursitis. The presence of ischiofemoral impingement may be indicated by pain caused by a combination of hip extension, adduction and external rotation. Magnetic resonance imaging demonstrates inflammation and oedema in the ischiofemoral space and quadratus femoris, and is distinct from an acute tear. To date this has only appeared in the specialist orthopaedic literature as a problem that has developed after total hip replacement, not in the unreplaced joint

Introduction and Objectives: One of the complications of hip arthroplasty is intraoperative fractures of the femur. In this study, we reviewed the incidence of intraoperative fractures in 118 hip arthroplasty surgeries using a stem from Meridian Howmedica, Rutherford, New Jersey, in an attempt to analyse the risk factors for intra-operative fractures and their relationship to short-term radiographic characteristics of the prosthesis. Our aim is to determine if there are risk factors associated with a higher incidence of intraoperative fractures in the following categories: patient, shape and dimensions of the femur, and relative size of the implant with respect to the medullary cavity. We will also determine if short-term follow up of patients with fractures yields radiographic information to indicate early loosening of the prosthesis. Materials and Methods: We studied 118 implants from consecutive operations performed from January 1997 to December 2000. The following variables were evaluated: general patient factors; local factors (characteristics of the femur); previous treatments, degree of femoral osteoporosis, type of femur, cervicodiaphyseal angle, femoral flring, “canal flare index”, cortical index, canal width 20mm proximal to the lesser trochanter, at the lesser trochanter, and 20mm distal to the lesser trochanter, pre-operative proximal and distal measurement of the stem, and if this coincides with the actual size of the stem; intraoperative factors: type of anaesthesia, patient positioning, surgical approach, experience of the surgeon, surgical time, the need for transfusion and number of units, the use of prophylactic cerclage, detection and localization of the intraoperative femoral fracture, and treatment of the same when they occurred; postoperative radiographic factors: level of cutting femoral neck, orientation of the stem (varus or valgus), proximal and distal stem size, proximal and distal packing of the canal, and length of the neck of the head of the prosthesis; radiographic factors 12 months postoperatively: stem orientation (varus or valgus), rounding of the calcar, cortical thickening, osteolysis, osteopenia, the presence of a ledge, the presence of lines of sclerosis, sinking of the stem, loosening of the ball, and the type of integration of the stem into the bone. Results: Of the 118 cases that were studied, intraoperative fractures occurred in 13 cases, representing an incidence of 11.01%, a somewhat higher rate than others have reported. We analyzed the occurrence of fractures in relation to the different variables in our study. We found a higher incidence of fractures in type A femurs (p< 0.05) and in cases of greater proximal filling by the implant (p< 0.05). Discussion and Conclusions: Though our study is limited in number of patients and length of follow-up time, it has demonstrated that the incidence of intraoperative fractures is associated with a narrow metaphyseal medullary cavity and predominately with a type A femur, which is a femur with low “canal flare index” values. Furthermore, since the risk of fracture is greater when we attempt to significantly adjust the size of the pros-thesis to the metaphysis, the incidence of fractures was higher when proximal filling was higher. However, cases of prosthesis with fractures did not present with radiographic appearance after 12 months that was worse than those femurs that were not fractured

Intraoperative fractures during primary total hip arthroplasty (THA) can occur on either the acetabular or the femoral side. A range of risk factors including smaller incision surgery, uncemented components, prior surgery, female sex, osteoporosis, and inflammatory arthritis have been identified. Acetabular fractures are rare but when they do occur often are underrecognised. It is not uncommon for intraoperative acetabular fractures to be discovered only postoperatively. Intraoperative acetabular fractures are associated with cementless implants and a number of identified anatomic risk factors. Factors related to surgical technique, including excessive under-reaming, excessive medialization with aggressive reaming, and implant designs such as an elliptical cup design are associated with higher risk. Treatment of acetabular fractures is dependent on whether they are diagnosed intraoperatively or postoperatively. When discovered intraoperatively, supplemental fixation should be added in the form of additional screw fixation, placing a pelvic plate, or using an acetabular reconstruction cage and morselised allografts. Acetabular reamings, obtained during preparation of the acetabulum, can be used for local bone graft. The goal should be stability of both the fracture and acetabular cup. Postoperatively, weight bearing and mobilization protocols may require modification, with many surgeons choosing a period of toe-touch weight-bearing in such cases. Acetabular fractures found postoperatively require the surgeon to make a judgement on the relative stability of the implant and the fracture to determine if immediate revision surgery or protected weight-bearing alone is appropriate. On the femoral side intraoperative fractures can occur around the greater trochanter, the calcar, or in the diaphysis. Fractures of the greater trochanter are problematic because of their tendency to displace due to the attachment of the abductors and the strong force they apply. Tension band wiring techniques will work for many greater trochanteric fractures while a trochanteric plate may be occasionally called for. With either form of fixation strong consideration should be given to 6–8 weeks of protected weight bearing postoperatively. Short longitudinal cracks in the medial calcar region are not rare with uncemented implants. Calcar fractures that do not extend below the lesser trochanter can often be managed with a single cerclage cable. Calcar fractures extending below the lesser trochanter should be scrutinised with additional intraoperative xrays; longer longitudinal cracks can be managed with 2 cables while more complex fractures that exit the diaphysis demand a change to a distally fixed implant and formal fracture reduction. Distal diaphyseal fractures are relatively uncommon in the primary setting, but not rare in the revision setting. When recognised intraoperatively, distal diaphyseal fractures can be treated effectively with cerclage cables. Distal diaphyseal longitudinal cracks noted postoperatively do not typically mandate a return to the OR and instead can be managed with 8 weeks of protected weight bearing

Objectives. The shape of proximal femur is important for the selection of implant in total hip arthroplasty (THA). There are few reports about the shape of proximal femur. We analyzed preoperative and postoperative conditions of the proximal femurs of patients before and after total hip arthroplasty with computed tomography (CT) and evaluated the compatibility to the cementless stem. Materials and Methods. We analyzed 65 hips of 63 patients (10 males and 53 females) who had THA between January 2008 and December 2010 in our hospital. We approximated the center of the femoral head as the center of the inscribed sphere in the femoral head. We defined the axis of proximal femur with the line between the centers of the circles located at 45 mm distal from lesser trochanter (LT) and at 90 mm proximal from LT. We measured the neck-shaft angle of femur, offset of femoral head, and diameter of bone-marrow cavity. After operation, we measured the distance between the stem surface and the edge of the femoral cortex (SF) at 10 mm proximal from LT to evaluate the compatibility of CT. We used PerFix HA cementless stem (Kyocera medical co., Osaka). Results. The mean diameter of femoral head was 46.1 mm, neck-shaft angle was 128.9 degrees, horizontal offset was 33.5 mm, and vertical offset was 41.6 mm. The mean diameters of bone-marrow cavity were 20.8 mm at 10 mm proximal level from LT, 14.2 mm at 20 mm distal level from LT and 9.9 mm at 100 mm distal level from LT. The medial shape was curved within 40 mm distal point from lesser trochanter. The mean of SF was 3.4 mm (0–5.1mm) and SF values of 43 hips were less than 2.0 mm. The mean of CFI was 3.6. Discussions and Conclusions. Several reports described about the shape of proximal femur on X-ray. However, it is inaccurate if we do not correct for the influence of anteversion angle of femur. For cementless stem, it is important to fit the medial area to the surface and the compatibility depends on the flare of the proximal femur

The design of hip replacements is based on the morphology of the proximal femur. Populations living in hard water regions have higher levels of serum calcium and magnesium which promote bone mineralization. A case control study was performed comparing proximal femoral morphology in patients living in soft and hard water regions to determine whether the effect of water hardness had an implication in the future design of hip-prostheses. The proximal femoral morphology of 2 groups of 70 aged and sex matched patients living in hard and soft water regions at mean age 72.24 (range, 50 to 87 years) were measured using an antero-posterior radiograph of the non-operated hip with magnification adjusted. The medullary canal diameter at the level of the lesser trochanter was significantly wider in patients living in the hard water region (mean width 1.9 mm wider; p=0.003). No difference was found at the isthmus, Dorr index, or cortical bone ratio. In conclusion proximal femoral morphology does differ: a wider medullary canal at the level of the lesser trochanter in hard water regions. This size difference is relatively small and is unlikely therefore to affect the mechanics of the current femoral stem prostheses components

The femur begins to bow anteriorly at the 200 mm level, but may bow earlier in smaller people. If the stem to be used is less than 200 mm, a straight stem can be used. If the stem is longer than 200 mm, it will perforate the anterior femoral cortex. I know this because I did this on a few occasions more than 20 years ago. To use a long straight stem, there are two techniques. One can either do a diaphyseal osteotomy or one can do a Wagner split (extended trochanteric osteotomy). Both of these will put the knee in some degree of hyperextension, probably insignificant in the elderly, but it may be of significance in the young. In very young people, therefore, it may be preferable to use a bowed stem to avoid this degree of recurvatum. There are two different concepts of loading. Diaphyseal osteotomy implies a proximal loading has been sought. The Wagner split ignores the proximal femur and seeks conical fixation in the diaphysis. There will be very little bone-bone contact between what remains of the attached femur and the detached anterior cortex so that it is important to ensure that the blood supply to the anterior cortex remains intact, preferably by using Wagner's technique, using a quarter-inch osteotome inserted through the vastus to crack the medial cortex. Current modularity is of two types. Distal modularity was attempted many years ago and was never successful. Proximal modularity, as for example, the S-ROM stem, implies various sizes of sleeves fit onto the stem to get a proximal canal fill. In mid-stem modularity, the distal stem wedges into the cone. It has to be driven into where it jams and this can be somewhat unpredictable. For this reason, the solid Wagner stem has been replaced by the mid-stem modular. Once the distal femur is solidly embedded, the proximal body is then selected for height and version. The proximal body is unsupported in the mid-stem modular and initially, few fractures were noted at the taper junction. Cold rolling, shot peening and taper strengthening seem to have solved these problems. There are a variety of types of osteotomy, which can be used for different deformities. With a mid-stem modular system, generally, all that needs to be done is a Wagner-type split and fixation is sought in the mid-diaphysis by conical reaming. No matter what stem is used, distal stability is necessary. This is achieved by flutes, which engage the endosteal cortex. The flutes alone must have sufficient rotational stability to overcome the service loads on the hip of 22 Nm. I divide revision into three categories. In type one, the isthmus is intact, i.e. the bone below the lesser trochanter so that a primary stem can be used. In type two, the isthmus is damaged, i.e. the bone below the lesser trochanter, so a long revision stem is required. In a type three, there is more than 70 mm of missing proximal femur. The Wagner stem may be able to handle this on its own, but most other stems are better supported with a structural allograft cemented to the stem. The reported long term results of mid-stem modular revision implants are good as in most, over 90% survivorship. The introduction of modularity appears to have overcome initial disadvantage of the Wagner stem, i.e. its unpredictability in terms of leg length

Aims. We have evaluated the survivorship, outcomes, and failures of an interlocking, reconstruction-mode stem-sideplate implant used to preserve the native hip joint and achieve proximal fixation when there is little residual femur during large endoprosthetic reconstruction of the distal femur. Methods. A total of 14 patients underwent primary or revision reconstruction of a large femoral defect with a short remaining proximal femur using an interlocking, reconstruction-mode stem-sideplate for fixation after oncological distal femoral and diaphyseal resections. The implant was attached to a standard endoprosthetic reconstruction system. The implant was attached to a standard endoprosthetic reconstruction system. None of the femoral revisions were amenable to standard cemented or uncemented stem fixation. Patient and disease characteristics, surgical history, final ambulatory status. ,. and Musculoskeletal Tumor Society (MSTS) score were recorded. The percentage of proximal femur remaining was calculated from follow-up radiographs. Results. All 14 at-risk native hip joints were preserved at a mean final follow-up of 6.0 years (SD 3.7), despite a short residual femur, often after proximal osteotomies through the lesser trochanter. Overall, 13 of 14 stems had long-term successful fixation. Eight patients required no reoperation. Three patients required reoperation due to implant-related issues, and three patients required reoperation for wound healing problems or infection. There were no dislocations or fractures. At final follow-up the mean MSTS score was 24.9 (SD 4.1). Nine patients required no ambulation aids, and only one had a Trendelenburg gait. Conclusion. This interlocking, reconstruction-mode stem-sideplate reliably preserves native hip joint anatomy and function after large femoral resection with a short remaining proximal femur, both in the primary and revision setting. This is particularly important for preventing or delaying total femoral arthroplasty in young patients after oncological reconstruction. Hip abductor strength and function could be maintained by this method, and the risk of dislocation eliminated. The success of this technique in this modest series should be verified in a larger collaborative study and will be of interest to revision surgeons and oncologists. Cite this article: Bone Joint J 2021;103-B(2):398–404

Resurfacing arthroplasty of the hip is being used increasingly as an alternative to total hip replacement, especially for young active patients. There is concern about necrosis of the femoral head after resurfacing which can result in fracture and loosening. Most systems use a cemented femoral component, with the potential for thermal necrosis of the cancellous bone of the reamed femoral head. We used thermal probes to record temperatures close to the cement-bone interface during resurfacing arthroplasty. The maximum temperature recorded at the cement-bone interface in four cases was approximately 68°C which was higher than that reported to kill osteocytes. A modified surgical technique using insertion of a suction cannula into the lesser trochanter, generous pulsed lavage and early reduction of the joint significantly reduced the maximum recorded cancellous bone temperature to approximately 36°C in five cases (p = 0.014). We recommend the modified technique since it significantly reduces temperatures at the cement-bone interface

To define the natural history of bone loss around a femoral prosthesis, the bone mineral content and bone mineral density were measured for each femur in 28 patients with unilateral total hip arthroplasty, 18 age-matched controls, and seven patients with unilateral osteoarthritis. The areas measured were inside the lesser trochanter and 4.8 cm distal to it. The contralateral hip served as the control. Three years after arthroplasty there was 40% loss in average bone mineral content inside the lesser trochanter, and 28% loss in average bone mineral content 4.8 cm distally in the medial cortex. At seven to 14 years after operation, patients had lost 40% of bone proximally and 49% distally. The data suggest that this may progress in a proximal-to-distal fashion, and could account for a 50% decrease in bone mass seven to 14 years after surgery

The shape of the femoral canal is variable, infact more variable than most contemporary designs of femoral components would suggest or accommodate. Clinical and experimental studies of total hip replacement have demonstrated the need for a close geometric fit between the femoral component and the supporting bone for a durable implant fixation. In order to provide a basis for design and selection of femoral components in future, we undertook an anthropometric study of proximal femoral geometry on Indian specimens. 74 cadaveric femorae were studied to analyze the difference in the endosteal and periosteal geometry between Indian and Western population. Standard extra-cortical and endosteal dimensions were determined by direct measurements of radiographs. To enable comparison standard horizontal and vertical axis were established using the geometric center of lesser trochanter and the bisecting axis of the medullary canal at the level of the isthmus. Statistically significant differences were found for the following measurements: Femoral head offset, Width at lesser trochanter, Width at lesser trochanter-20mm, Proximal border of isthmus, Neck shaft angle

A mild degree of femoral deformity can be accommodated in total hip replacement by using a small, cemented stem, but this results in abnormal mechanics and potentially early failure. Minor degrees of rotatory and angular deformity proximal to the lesser trochanter can be handled by a custom or modular implant, which will allow changes in version and offset. Deformities below the lesser trochanter should be corrected by osteotomy. This is true of rotational and angular deformity. Where there is a leg length problem, a shortening osteotomy can be carried out at the subtrochanteric region. To achieve angular stability after osteotomy, full canal fill over 5 cm or more is preferable. The rotational stability can be achieved by step cuts, side plates, etc. If the implant is distally fluted with thin, sharp flutes and if it is capable of giving proximal rotational control then simple horizontal butt joint osteotomy is all that is required. The osteotomy should be carried out at the summit of the deformity and proximal and distal prophylactic cerclage wiring is advised. If the gluteal muscles are weak as they may be in a high DDH case, a subtrochanteric osteotomy will allow leg length balancing, correction of proximal anteversion, and if the proximal fragment is retrograde reamed exiting through the neck cut rather than the periform fossa, lateralisation to increase the gluteal power can be achieved

The reproduction of ideal offset is an aim of hip replacement. Determining this measurement from traditional radiology techniques is inaccurate because femoral neck anteversion will foreshorten the femoral neck offset in a standard two dimensional x-ray making the measurement “apparent”. A novel method of determining offset is presented. A computer software program has been developed for pre-operative planning of joint replacements, (Orthopaedic Work Station). The program relies on using a CT scout film for magnification correction and to determine measurement parameters including leg length difference. It was recognised that by collecting extra cross-sectional references that three-dimensional measurement of offset would be possible. The CT scanner has software that allows determination of:. The location of the centre of the femoral head. The centroid of the femoral shaft at a point just below the lesser trochanter. The centroid of the femoral shaft at a point 150mm below the lesser trochanter. For this study the line joining the two centroids is considered the longitudinal axis of the femur. The CT scanner has software that also allows for the centroids to be moved along the longitudinal axis into the plane represented by a perpendicular line from the longitudinal axis to the centre of the femoral head. It is a simple matter to measure the distance between the centroid and the centre of the femoral head to obtain a true offset. A phantom femur was measured using the radiology method described and then measured directly. Exact correlation was established. A study of inter-observer measurement has shown statistically consistent agreement using six observers in twenty cadaver femurs. The method is accurate and uses existing data collected as part of the pre-operative planning process. CT scanning prior to hip replacement, gives less radiation exposure and is more efficient with respect to radiology services than conventional radiology. An intraoperative study may require ethics approval

Introduction and Aims: Patient presented with an equinovarus deformity of the left foot and ankle, and high above knee amputation of right leg. Femoral stump extended 6cm below lesser trochanter. Patient was wheelchair bound. Aim: Lengthening of stump, ensuring proper prosthesis fitment. Correction of left-side deformity, by means of calcaneal tibial fusion. Method: A tibio-calcaneal fusion of ankle was performed, correcting equinovarus deformity. Patient fitted with orthotic boot with rocker bottom sole. Corticotomy was performed below lesser trochanter and an Orthofix Limb Reconstruction System was used to lengthen stump. Lengthening started 10 days post-surgery. Five months later l0cm of length had been added. Fixator was left in situ. Six months later, the ex-fix was removed after consolidation of calus. Five months later patient had a new prosthesis fitted and a further five months later, patient was walking with prosthesis, and orthosis for the left ankle, assisted with one crutch. Results: By July 2003, the patient was walking with a prosthesis and the length gain of the stump on the right was 10cm. The full length of the right femur was now 25cm, allowing a proper above knee prosthesis. The left ankle is fused in a functional position and completely pain free. Full weight-bearing is now possible, albeit with a rocker bottom sole. Conclusion: Lengthening of a short femoral stump is a useful procedure to create a suitable stump for an above knee prosthesis, certainly if one considers that the alternative is an ischial weight-bearing caliper

Localised femoral endosteal bone lysis at or distal to the level of the lesser trochanter can occur soon after cemented hip arthroplasty or as long as 15 years later in a hip that has otherwise functioned perfectly well. The first important question about these lesions is why they occur, and the second, why they occur where they do. Particulate debris, particularly from wear of ultra-high molecular weight poly-ethylene, is commonly regarded as the cause, but changes in hydrostatic pressure may play a more important role than previously thought. Because the femur bows anteriorly and posteriorly, deficiencies in the cement mantle are particularly likely to occur in relation to the interior aspect of the stem at the level of the lesser trochanter and in relation to the tip of the stem posteriorly. We suggest that localised lytic lesions occur at the sites of defects in the cement mantle. There is evidence that with pressure changes, joint fluid and whatever particles it contains come into contact with the endosteal surface of the femur at the sites of these mantle defects. Such lesions occur only rarely when polished stems are used. With matt stems, abrasive wear enlarges the internal dimension of the cement mantle, increasing the size of the fluid conduit between stem and cement. Matt surfaced stems retrieved from patients with localised lysis show evidence of both abrasive wear and slurry wear, ‘wear caused by hard particles carried in fluid’. The nature of the changes due to slurry wear shows that the flow of fluid along these stems is from distal to proximal. As the stem becomes increasingly unstable inside the cement mantle owing to wear, the hydrostatic effects on increased stem movement become magnified and may on their own produce bone lysis

Purpose. CentPillar GB HA stem (stryker®) is developed as the stem fitting the Japanese femur, and now there is CentPillar TMZF HA stem (stryker®) as the improvement type of the stem by coating the PureFix HA with plasma spray. We observed the factors which influenced on the stem subsidence between the two-type stems. Materials and Methods. We intended for 26 hips 23 patients that we performed total hip arthroplasty (THA) during the period between January 2005 and June 2009 and were able to follow up more than three years. 10 males 11 hips and 13 females 15 hips, the mean age at the time of surgery was 56.5 (range, 29–74) years old, and primary diseases were osteoarthritis (OA) in 17 hips, Idiopathic Osteonecrosis of Femoral Head (ION) in six hips, and rheumatoid arthritis (RA) in three hips. 16 hips were treated with the CentPillar GB HA stem (G group), and 10 hips were performed with the CentPillar TMZF HA stem (T group). The examination items are the stem size, the canal fill ratio of the stem (the top of lesser trochanter, the bottom of lesser trochanter, the distal portion of the stem) and the stem alignment (on anteroposterior radiograph and Lauenstein view). Results. The mean stem subsidence was 1.75 mm (range, 0–8.9 mm) in the G group, and 0.87 mm (range, 0–2.9 mm) in the T group. Although there was no significant difference, it accepted the tendency that the stem subsidence in the G group was larger than its in T group. The case in which the stem subsidence more than 2 mm was found at were 7 hips in the G group, whereas it was only one hip in the T group. The stem size, the canal fill ratio of the stem and the stem alignment were no meaningful effect on the stem subsidence. In F-test, the stem subsidence of the G group had significantly large dispersion compared with the T group (P<0.01). Discussion and Conclusion. Although there were no significant differences in the stem subsidence between the two groups, the variation of the stem subsidence was significantly small in the T group. We examined the factor which affected the stem subsidence, but neither item recognized meaningful relation, and the influence such as differences of the surface processing was considered. In fact, the strength of the TMZF HA stem improved for the GB HA stem with TMZF titanium alloy, the contact area with the bone spread by coating the PureFix HA with plasma spray, the elasticity of TMZF became closer to the bone, and the strong proximal fixation were enabled. In THA with the GB HA stem, variation of the stem subsidence was significantly large, so considerable attention for the excessive stem subsidence was required

Introduction. The debate regarding the importance of preserving the blood supply to the femoral head (FH) and neck during hip resurfacing arthroplasty (HRA) is ongoing. Several surgeons continue to advocate for the preservation of the blood supply to the resurfaced heads for both the current HRA techniques and more biologic approaches for FH resurfacing. Despite alternative blood-preserving approaches for HRA, many surgeons continue to use the posterior approach (PA) due to personal preference and comfort. It is commonly accepted that the PA inevitably damages the deep branch of the medial femoral circumflex artery (MFCA). This study seeks to evaluate and measure the anatomical course of the ascending and deep branch of the MFCA to better describe the area in danger during the posterior approach. Methods. In 20 fresh-frozen cadaveric hips, we cannulated the MFCA and injected a urethane compound. The Kocher-Langenbeck approach was used in all specimens. The deep branch of the MFCA was identified at the proximal border of the QF and measurements were taken. The QF was incised medially and elevated laterally, maintaining the relationship of the ascending branch and QF, and distances from the lesser trochanter were measured. The deep branch was dissected and followed to its capsular insertion to assess the course and relation to the obturatur externus (OE) tendon and the conjoint tendon (CT) of the short external rotators. Results. Gross dissection revealed that the transition point from transverse to ascending branch of the MFCA at the anterior surface of the QF was at an average distance of 2.2 cm (range 2–2.3 cm) proximal and 1.2 cm (range 0.5–1.9 cm) medial to the lesser trochanter. The ascending branch runs caudally within fat tissue that divides the QF and OE at an average distance of 1.5 cm (range 0.7–2.3 cm) from the QF greater trochanter insertion. At the superior border of the QF, the MFCA continues as the deep branch posterior to the OE tendon at an average distance of 1.3 cm (range 0.6–1.9 cm) from the OE femoral insertion. The deep branch was noted to enter the capsule at an average distance of 0.3 cm (range 0–0.5 cm) from the distal border of the CT and 1.2 cm (range 0.6–1.9 cm) from the CT femoral insertion. Discussion and Conclusion. The ascending branch of the MFCA runs in the anterior surface of the QF at a distance of 1.5 cm from the femoral insertion. When the QF myotomy is performed, commonly 0.5–0.8 cm from the insertion to the femur, the vessel get disrupted or stays medial to the myotomy and can stretch/disrupt when the femur is dislocated and translated anteriorly. Tenotomies of the OE and CT should stay at least 1.5 cm from the femoral insertion to preserve the deep branch of the MFCA. This study provides unreported topographic anatomy of the ascending and deep branch of the MFCA, which can help develop an improved blood-preserving posterior approach for HRA

Purpose: The anatomy of the endosteal canal of the proximal femur varies greatly in the general population. This variability can compromise total hip arthroplasty when a femoral stem is inserted without cement. While the secondary fixation of the implant is dependent on several parameters, the predominant factor is the primary stability and the large contact between the bone and the treatment surface of the apposed prosthesis. These two conditions, necessary but insufficient to guarantee an excellent clinical result, are obtained if there is a correct bone-implant morphology match. We analysed the morphology of the endosteal canal of the proximal femur to determine whether there is a standard anatomic conformation justifying the use of line prostheses. Material and methods: We examined 30 femurs harvested from 30 individuals in a consecutive series in our anatomy laboratory. We made 12 scanner slices parallel to the knee joint line starting 1 cm above the apex of the lesser trochanter going up to 11 cm above the lesser trochanter. For each slice, we assimilated the canal to an ellipsoid surface to characterise its barycentre, the angle of the greater axis relative to the reference plane of the posterior condyles, and its dimensions defined with length (greater axis), and width (perpendicular to the greater axis). Results: For each femur, the AP projections of the barycentres fell on a straight line (anatomic axis) and the lateral projections on a parabole. Helitorsion, i.e. the difference in the torsion angles between the first slice and the last slice was constant (57±8.5°). The dimensions were recorded for each slice. Discussion: This method can be criticised. We were able to confirm the tridimensional data reported by Noble and confirmed the notion of a somatotype. We defined the normal (statistical) equation of the endosteal canal for the proximal end of the femur (barycentre, dimensions). Conclusion: The anatomy of the endosteal canal of the upper extremity of the femur is not variable but standardised. It is thus possible to adapt the bone to the prosthesis

Aim: The evaluation and guantification of radiologic parameters observed in the late stages of hip arthritis. Materials and Methods : The present study concerns the retrospective evaluation of the preoperative X-rays of 80 patients affected from primary hip arthritis only on one side in an advanced stage, that were treated in our department with total hip arthroplasty. From the present study we excluded patients with hip arthritis secondary to trauma, rheumatoid arthritis or congenital hip dislocation. The onset of the symptoms ranged between six months and twenty years (mean time5, 6 years). We evaluated the following parameters:. Neck-shaft angle. The thickening of the Calcar. The Bone loss-sedimentation of the head of the femur. The cortex thickness at the level of the lesser trochanter. The distance-on the axis of the femur’s neck-between the rotation center of the hip and the point where the above axis crosses the transtrochanteric line. These parameters were measured from two idependent observers. Every single measurement was done twice from both observersjn order to estimate the interobserver and the intraobserver error. The measurements were done in both hips of the patients-the affected and the healthy one-on an A-P pelvis radiogramm. Results: From the above measurements, it results that in hip arthritis the neck-shaft angle changes (it becomes varous).The calcar was found thickened in the affected hip in a mean value of 1,45mm. The thickness of the cortex at the level of the lesser trochanter was found greater in the non-affected side in a mean value of 0,7mm. The bone loss of the femur head was approximately 2,5mm. The distance between the rotation center of the hip and the point at which the neck axis crosses the transtrochanteric line was found greater in the non-affected side, in a mean value of 3,12mm. Conclusions: The modifications observed in hip arthritis that concern the load transmission across the neck of the femur result in changes that can be radiologically identified and measured. In the first place the thickness of the calcar is influenced, as it does the distance between the rotation center of the hip and the trochanteric line. In the advanced stages of hip arthritis the sedimentation (bone loss) of the femur head can also be measured

The most common classification of periprosthetic femoral fractures is the Vancouver classification. The classification has been validated by multiple centers. Fractures are distinguished by location, stability of the femoral component, and bone quality. Although postoperative and intraoperative fractures are classified using the same three regions, the treatment algorithm is slightly different. Type A fractures involve the greater and lesser trochanter. Fractures around the stem or just distal to the stem are Type B and subcategorised depending on stem stability and bone quality. Type C fractures are well distal to the stem and are treated independent of the stem with standard fixation techniques. The majority of fractures are either B1 (stable stem) or B2 (unstable stem). The stem is retained and ORIF of the fracture performed for B1 fractures. B2 and B3 fractures require stem revision with primary stem fixation distal to the fracture. Intraoperative fractures use the same A, B, C regions but are subtyped 1–3 as cortical perforations, nondisplaced, and displaced unstable fractures, respectively. With the exception of A1 intraoperative fractures all other intraoperative fractures require surgical treatment. A recent publication utilizing a New York state registry highlighted the patient risk of mortality associated with periprosthetic hip fractures. One month, 6 month and 1 year mortality was 3.2%, 3.8% and 9.7%, respectively. The mortality risk was lower for periprosthetic fractures treated with ORIF at 1 and 6 months compared to fractures requiring revision total hip

Purpose: The purpose of this work was to demonstrate the presence of polyethylene particles at the fixation interfaces of the femoral and acetabular components of non-dislocated cemented hip prostheses that had functioned in vivo for several years. Material and methods: Three femoral components and two acetabular cups were recovered in two patients who died from an intercurrent cause. The first patient, an 85-year-old woman, had had a hip prosthesis for eight years. There was no radiological sign of displacement nor cup wear (stainless steel /polyethylene cup). For this same patient, the other hip had be revised for acetabular loosening three months prior to death. The femoral component was not loosened; it had been removed with its cement then reimplanted within the same cement sheath that was not removed. The cement/bone interface was thus preserved at eight years. In the second patient, a woman aged 88 years, the delay was nine years. This patient had no radiographic sign of loosening. The polyethylene acetabular insert exhibited 1 mm linear wear. This was a ceramic /polyethylene cup. The specimens were prepared by decalcification and defatting then fixation in buffered formol (pH 7.2) before embedding in polymethyl-metacrylate. After hardening, a diamond-tipped diatome to obtain transverse section of the femur at four levels: lesser trochanter, 2 cm below the lesser trochanter, 1 cm above the tip of the stem, 1 cm below the distal tip of the stem. After polishing, the 50 μ thick sections were stained with Picrofuschin von Jienson. The polyethylene acetabular cups were prepared likewise. Polyethylene particles were counted under polarised optic microscope at each cement /implant and cement /bone interface using an image analyser (Histolab, microvision instruments, Evry, France). Results: There was no evidence of a fibrous membrane between the bone and the cement. A 10 to 20 mm space was sometimes observed at the metal /cement interface. Polyethylene particles measuring 3 to 10 μm were found at both cement /bone and metal /cement interfaces, including at the distal femur level. Particles were observed in the cement at several sites. Conclusion: Large-sized polyethylene particles migrate around non-displaced cemented implants, partidularly between bone lines, and can follow the cement poriosity

Introduction. Traditionally, conventional radiographs of the hip are used to assist surgeons during the preoperative planning process, and these processes generally involve two-dimensional X-ray images with implant templates. Unfortunately, while this technique has been used for many years, it is very manual and can lead to inaccurate fits, such as “good” fits in the frontal view but misalignment in the sagittal view. In order to overcome such shortcomings, it is necessary to fully describe the morphology of the femur in three dimensions, therefore allowing the surgeon to successfully view and fit the components from all possible angles. Objective. The objective of this study was to efficiently describe the morphology of the proximal femur based on existing anatomical landmarks for use in surgical planning and/or forward solution modeling. Methods. Seven parameters are needed to fully define femoral morphology: head diameter, head center, neck shaft axis, femoral canal, proximal shaft axis, offset, and neck shaft angle. A previous algorithm has been developed in-house to automatically locate anatomical landmarks of patient specific bone models. Once the bone model has been aligned and scaled based on these landmarks, the femoral head diameter and center are calculated by iteratively fitting a sphere to the corresponding femoral head point cloud. An iterative cylindrical fitting algorithm is used to describe the neck shaft axis. The femoral canal is determined using three steps: 1) the femur is sliced at 10mm increments below the lesser trochanter, 2) the femoral canal boundary is determined at each slice, and 3) the largest circle is fit within each slice's canal boundary. The proximal shaft axis is described by fitting a line to the canal circle center locations. Offset is defined as the distance from the head center to the proximal shaft axis. Finally, the neck shaft angle is the angle between the neck shaft axis and the proximal shaft axis. Results. The goal pertaining to femoral component morphology is to provide meaningful information that can be used to determine how the femoral stem fits within the canal. Regardless of differences in bone sizes and geometries, the algorithm has proven to be successful in describing the femoral morphology of a patient-specific bone model. Discussion. These results lay the groundwork for an automatic stem fitting algorithm, which is described in a subsequent abstract. The morphology knowledge of the femoral head, femoral neck, femoral canal, and various axes can be coupled with known THA component parameters (such as offset, neck length, neck shaft angle, etc.) to allow our algorithms to predict the “best selection” and “best fit” for the femoral stem. This can also be applied to the acetabulum and can then be used as a surgical planning tool as well as a parameter when modeling postoperative predictions. For any figures or tables, please contact authors directly

Introduction. Instability continues to be the number one reason for revision in primary total hip arthroplasty (THA). Commonly, impingement precedes dislocation, inducing a levering out the prosthetic head from the liner. Impingement can be prosthetic, bony or soft tissue, depending on component positioning and anatomy. The aim of this virtual study was to investigate whether bony or prosthetic impingement occurred first in well positioned THAs, with the hip placed in deep flexion and hyperextension. Methods. Twenty-three patients requiring THA were planned for a TriFit/Trinity ceramic-on-poly cementless construct using the OPS. TM. dynamic planning software (Corin, UK). The cups were sized to best fit the anatomy, medialised to sit on the acetabular fossa and orientated at 45° inclination and 25° anteversion when standing. Femoral components and head lengths were then positioned to reproduce the native anteversion and match the contralateral leg length and offset. The planned constructs were flexed and internally rotated until anterior impingement occurred in deep flexion [Fig. 1]. The type (bony or prosthetic), and location, of impingement was then recorded. Similarly, the hips were extended and externally rotated until posterior impingement occurred, and the type and location of impingement recorded [Fig. 2]. Patients with minimal pre-operative osteophyte were selected as a best-case scenario for bony impingement. Results. 6/23 (26%) patients were planned with only a 32mm articulation (<50mm cup size), with the remaining 17 patients all planned with both 32mm and 36mm articulations (≥50mm cup size). Anterior impingement was 26% prosthetic and 74% bony with the 32mm articulations, and 100% bony with the 36mm articulations. Bony impingement in deep flexion was exclusively anterior neck on anterior inferior iliac spine. Posterior impingement was 57% prosthetic and 43% bony with the 32mm articulations, and 41% prosthetic and 59% bony with the 36mm articulations. Bony impingement in hyperextension was exclusively lesser trochanter (LT) on ischium. Of the patients planned with both 32mm and 36mm articulations, there was a 14% increase in prosthetic impingement when a 32mm head was planned (35% and 21% respectively). Discussion. Impingement in THA usually precedes dislocation and should be avoided with appropriate component positioning. We found that in hyperextension, prosthetic and bony impingement were equally common. In deep flexion, impingement was almost exclusively bony. Further studies should investigate the effects of stem version, cup orientation, liner design, cup depth, native offset and retained osteophytes on the type of impingement in THA. For any figures or tables, please contact the authors directly

Introduction. The success of cementless total hip arthroplasty (THA) depends on the primary stability of the components. One of the biomechanical factors that comes into play is the mechanical quality of the bone. To our knowledge, there are no reported studies in the literature analyzing the impact of the preoperative bone mineral density on the outcomes of cementless THA. The goal of the study was to analyze the clinical results at 2 year follow-up according to the preoperative cancellous bone mineral density (BD). Our hypothesis was that the clinical outcomes were correlated to the BD. Material and methods. From January to June 2013, a prospective study included patients who underwent a cementless THA using a proximally shortly fixed anatomic stem. A 3D preoperative CTscan-based planning was performed according to the routine protocol using the Hip-Plan software in order to determine the hip reconstruction goals as well as the implants size and position. The Hounsfield bone density (BD) of the metaphyseal cancellous bone was computed in a volume (of 1 mm thick and of 1cm² surface) at the level of the calcar 10 mm above the top of the lesser trochanter and laterally to the medial cortical (Figure 1). Intra-and inter-observer repeatability measurements were performed. Patients were clinically assessed at 2 years follow-up using self-administered auto-questionnaires corresponding to the Harris and the Oxford scores. A Multivariate statistical analysis assessed correlations between clinical scores, age, gender, body mass index, and BD. Results. 50 patients were included consisting of 29 men and 21 women, with an average age of 62 ± 12 years and an average BMI of 25.8. The average preoperative BD was 69.4 ± 54 HU. At 2 years follow-up, the hip function scores were significantly correlated with the preoperative BD (0.42, p = 0.002) and the age (0.39, p = 0.005). However, there was no significant correlation between BD and BMI. Discussion Bone density appears to be an important parameter to consider when planning THA. This highlights also the importance of preoperative image calibration. Conclusion. The functional outcomes after cementless THA are correlated with preoperative cancellous bone density. Bone density needs to be integrated into THA 3D planning

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky Type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Posterior extraarticular ischiofemoral hip impingement can be caused by high femoral torsion and is typically located between the ischium and the lesser trochanter. We asked if patients undergoing derotational femoral osteotomies for posterior FAI have (1) decreased hip pain and improved function and evaluated (2) subsequent surgeries and complications?. Thirty-three hips undergoing derotational femoral osteotomies between 2005 and 2016 were evaluated retrospectively. Of them 15 hips underwent derotational femoral osteotomies and 18 hips underwent derotational femoral osteotomies combined with varisation (neck-shaft angle >139°). Indication for derotational osteotomies was a positive posterior impingement test in extension and external rotation, high femoral torsion (48° ± 9) on CT scans and limited external rotation. Offset improvement was performed to avoid intraarticular impingement in hips with a cam-type FAI. All patients were female and mean followup was 3 ± 2 (1 – 11) years. At latest followup the positive posterior and anterior impingement test decreased from preoperatively 100% to 5% (p< 0.001) and from preoperatively 85% to 30% (p< 0.001). The mean Merle d'Aubigné Postel score increased from 14 ± 1 (11 – 16) to 16 ± 1 (13 – 17) at latest followup (p< 0.001). At followup 32/33 hips had been preserved and one hip had been converted to a total hip arthroplasty (THA). In two hips (6%) revision osteosynthesis was performed for delayed healing of the femoral osteotomy. Derotational femoral osteotomies for the treatment of posterior extraarticular ischiofemoral impingement caused by high femoral torsion result in decreased hip pain and improved function at midterm followup but had 6% delayed healing rate requiring revision surgery

The Failed Femoral Neck Fracture. For the young patient: Attempt to preserve patient's own femoral head. Clinical results reasonably good even if there are patches of avascular necrosis. Preferred methods of salvage: valgus-producing intertrochanteric femoral osteotomy: puts the nonunion under compression. Other treatment option: Meyer's vascularised pedicle graft. For the older patient: Most reliable treatment is prosthetic replacement. Decision to use hemiarthroplasty (such as bipolar) or THA based on quality of articular cartilage, perceived risk of instability problem. In most patients THA provides higher likelihood of excellent pain relief. Specific technical issues: (1) hardware removal: usually remove after hip has first been dislocated (to reduce risk of femur fracture); (2) Hip stability: consider methods to reduce dislocation risk: larger diameter heads/dual mobility/anteriorly-based approaches; (3) Acetabular bone quality: poor because it is not sclerotic from previous arthritis; caution when impacting a pressfit cup; low threshold to augment fixation with screws; don't overdo reaming; just expose the bleeding subchondral bone. A reasonable alternative is a cemented cup. The Failed Intertrochanteric Hip Fracture. For the young patient: Attempt to salvage hip joint with nonunion takedown, autogenous bone grafting and internal fixation. For the older patient: Decision to preserve patient's own hip with internal fixation versus salvage with hip arthroplasty should be individualised based on patient circumstances, fracture pattern, bone quality. THA is an effective salvage procedure for this problem in older patients. If prosthetic replacement is chosen special considerations include:. THA vs. hemiarthroplasty: hemiarthroplasty better stability; THA more reliable pain relief. Removal of hardware: be prepared to remove broken screws in intramedullary canal. Management of bone loss: bone loss to level of lesser trochanter common. Often requires a calcar replacement implant. Proximal calcar build-up size dictated by bone loss. Length of stem: desirable to bypass screw holes from previous fixation, if possible. Stem fixation: cemented or uncemented fixation depending on surgeon preference, bone quality. If uncemented, consider diaphyseal fixation. Greater trochanter: often a separate piece, be prepared to fix with wires or cable grip. Residual trochanteric healing, hardware problems not rare after THA

We maintain a database on 1000 femoral revisions using extensively porous-coated stems. Using femoral rerevision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 mm or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Purpose. To observe the follow-up results of standard cemented bipolar hemiarthroplasty with double loop and tension band wiring technique for treatment of unstable intertrochanteric hip fractures in elderly patients with osteoporosis. Materials and Methods. From May 2000 to May 2006, 86 cemented bipolar hemiarthroplasties were performed in elderly patients who had unstable intertrochanteric fractures. The mean age at the time of surgery was 82 years old. The average follow-up period were 5.3 years. We evaluated post-operative results after operation by clinical and radiographic methods. Results. Clinically, the final follow-up of Harrsi hip score was noted 79.2. The mean time needed for full weight bearing following surgery was 4.2 weeks and 82.5% of patients regained their preoperative ambulatory level. All patients achieved union in lesser trochanter fracuture, but great trochanter displacement were observed in 4 cases. There was one case of acetabular erosion. Post-operative superficial infections were found in 2 cases. 1 case with stem subsidence(<5 mm) showed satisfactory results without further subsidence in follow-ups. Conclusion. If we properly apply indications in technique with cemented bipolar hemiarthroplasty in the treatment of unstable intertrochanteric hip fracture in elderly, we will achieve systematic postoperative rehabilitation, pain control and handy nursing which is its one of merits

Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight press fit. The prevalence has been reported to be between 1–5% in cementless THAs. The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary, and especially in revision, THA be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery, when taking the stem out from above, make sure the area of the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO, place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem, a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty, calcar fractures are by far the most common. If using proximal fixation and you are certain the stem is stable, then all that is needed is cerclage wiring. As already mentioned, you must follow the fracture line distally so you are aware of how far down it goes. Often what appears to be a calcar split actually propagates distal to the lesser trochanter. In these cases, one would probably go for distal fixation plus wiring. In conclusion, intra-operative femoral fractures are on the rise. Prevention is the key

Background. Intramedullary nailing is a widely accepted treatment method for femoral fractures. Failure of locking screws is often a threatening complication, particularly on comminuted fractures. For comminuted fractures, the locking nails are load-bearing devices. The load transfer between fractured fragments is made through especially the locking screws for these load bearing situations. Nonunion, malunion, delayed union, shortening, and nail migration are the expected results if early failure of locking screws is present with comminuted fractures. In this study our aim was to compare the bending resistance of titanium and stainless steel locking screws. Methods. We tested 60 locking screws in six groups (titanium, stainless steel, unthreaded, low threaded and high threaded) in a steel tube that has 30 mm inner diameter, which imitates the lesser trochanter level. We determined the yield points at three-point bending tests that permanent deformation started in the locking screws using an axial compression testing machine. Results. The three-point bending resistance of 5 mm low threaded titanium locking screws (bending at 1413 N loading) was 46.5 % less than the three-point bending resistance of 5 mm low threaded stainless steel locking screws (bending at 2171 N loading) (p < 0.001). Five mm stainless steel locking screws are 29–57 % more resistant to three-point bending deformation than titanium ones. Conclusions. Therefore, stainless steel locking screws instead of titanium ones must be preferred in comminuted femur shaft fractures. In intramedullary nailing of comminuted or long oblique femur fractures, a locking screw should be 5 mm low threaded or unthreaded stainless steel or 5 mm unthreadedtitanium. Five mm high threaded titanium or stainless steel screws must not ever be used as a locking screw. Level of Evidence. 5. Disclosure. Authors declare that there is no conflict of interest related to the present study

INTRODUCTION. Loosening is a major cause for revision in uncemented hip prostheses due to insufficient primary stability. Primary stability after surgery is achieved through press-fit in an undersized cavity. Cavity preparation is performed either by extraction (removing bone) or compaction (crushing bone) broaching. Densification of trabecular bone has been shown to enhance primary stability in human femora; however, the effect of clinically used compaction and extraction broaches on human bone with varying bone mineral density (BMD) has not yet been quantified. The purpose of this study was to determine the influence of the broach design and BMD on the level of densification at the bone-cavity interface, stem seating, the bone-implant contact area and the press-fit achieved. METHODS. Paired human femora (m/f=11/12, age=60±18 y) were scanned with quantitative computed tomography (QCT, Philips Brilliance 16) before broaching, with the final broach, after its removal and after stem implantation. Compaction broaching (n=4) was compared in an in situ (cadaver) study against extraction broaching with blunt tooth types (n=3); in an ex situ (excised femora) study, compaction broaching was compared against extraction broaching with sharp tooth types (n=8 each). QCT data were resampled to voxel sizes of 1×1×1 mm (in situ) and 0.5×0.5×1 mm (ex situ). Mean trabecular BMD of the proximal femur was determined. The cavity volumes were segmented in the post-broach images (threshold: −250 mgHA/cm3, Avizo 9.2) and a volume of interest (VOI) of one-voxel thickness was added around the cavity to capture the interfacial bone. VOIs were transferred to the pre-broach image and bone densification was calculated within each VOI as the increase from pre- to post-broach image (MATLAB). Detailed surface data sets of broaches and stems were collected with a 3D laser-scanner (Creaform Handyscan 700) and aligned with the segmented components in the CT scans (Fig. 1). Stem seating was defined as the difference between the top edge of the stem coating and the final broach. Distance maps between the stem and cavity surface were generated to determine the bone-implant contact area and press-fit. All parameters were analysed between 5 mm distal to the coating and 1 cm distal to the lesser trochanter and analysed with related-samples Wilcoxon signed rank and Spearman's correlation tests (IBM SPSS Statistics 22). RESULTS. Trabecular BMD ranged from 81 to 221 mgHA/cm3. Densification was higher with compaction compared to sharp (p=0.034), but not blunt extraction broaching (p=1.000). Proximal bone-implant contact area, press-fit and stem seating did not differ between broaching methods. Bone-implant contact area and bone densification increased with trabecular BMD (rs=0.658, p=0.001 and rs=0.443, p=0.034), press-fit with stem seating (rs=0.746, p<0.001) and contact area with bone densification (rs=0.432, p=0.039). DISCUSSION. Sharp extraction broaching reduces densification at the bone-cavity interface, but does not affect the press-fit or contact area. Trabecular BMD was positively associated with contact area, and stem seating with press-fit. Future studies will aim to link these findings to primary stability and influence on periprosthetic fractures. For any figures or tables, please contact authors directly

Prevention: Many periprosthetic femur fractures may be prevented by: good patient follow-up; timely reoperation of lytic lesions if radiographs suggest fracture risk; prophylactic use of longer stemmed implants or strut grafts to bypass cortical defects at revision surgery. Treatment: Periprosthetic fractures can be treated using an algorithmic approach based on the Vancouver classification system. Fractures of greater or lesser trochanter (Type A): nonoperative treatment if displacement acceptable and if not associated with lysis; operative treatment if displacement unacceptable or associated with progressive lysis. Fractures of distal femur well distal to implant (Type C): treat as any other femur fracture, usually operatively; fixation options: plate/retrograde nails. Fractures around the implant or at its tip (Type B): these fractures almost always require surgery. Nonoperative treatment is associated with high rate of malunion, nonunion, poor results. Treatment is according to fixation status of implant and bone quality. Well-fixed stem (Type B1): ORIF with cable plate and/or strut grafts; or with locking plate and minimally invasive biologic technique. Loose stem (Type B2 and Type B3): revise implant to long stem; usually use uncemented distally-fixed implant; occasionally long cemented stem (avoid cement extrusion). In most cases we favor use of a modular fluted tapered stem which provides axial and rotational stability by fixation distal to the fracture. Principles: obtain fracture stability, implant stability, and optimise conditions for bone healing (use bone grafts, don't strip periosteum)

We present the case of a 65-year-old man who developed a malignant fibrous histiocytoma at the lesser trochanter five months after a cementless hip replacement. We have reviewed reports of similar cases and discuss them in terms of the possible mechanisms of sarcomatous degeneration and the latency of such changes

1. A patient of sixty-eight suffering from enchondromatosis (Ollier's disease) is described. 2. A malignant tumour developed in the region of the lesser trochanter of the femur. Histological investigation established that it was an osteosarcoma. 3. Other features of interest are the radiographic appearance of Ollier's disease at an advanced age, and the presence of subcutaneous subcostal and retroperitoneal haemangiomata

Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight pressfit. The prevalence has been reported to be between 1–5% in cementless total hip arthroplasties (THAs). The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary and especially in revision THA, be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer as good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery when taking the stem out from above, make sure the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty calcar fractures are by far the most common. If using proximal fixation and you are certain the stem is stable, then all that is needed is cerclage wiring. As already mentioned, you must follow the fracture line distally so you are aware of how far down it goes. Often what appears to be a calcar split actually propagates distal to the lesser trochanter. In these cases, one would probably go for distal fixation plus wiring. In conclusion intra-operative femoral fractures are on the rise. Prevention is the key. If a fracture, exposure is the key to deciding on a treatment plan

Patients with osteochondrodysplasia frequently require Total Hip Arthroplasty at a younger age, as a result of early degenerative disease of the hip joint. The outcome of Modular Total Hip Arthroplasty in this group of patients has been reported previously. In this retrospective study we evaluated the outcome of custom made (CADCAM) Total Hip Arthroplasty in patients with osteochondrodysplasia. Between 1974 and 2009, twenty one CADCAM Total Hip Arthroplasty procedures were performed in fourteen patients in our institution. There were eight female and six male patients, with the mean age at time of surgery of 40.95 years (20 to 78). The patients were followed up clinically and with the Harris hip score for a mean of 7.12 years (0.5 to 17 years). Four of the twenty-one hips (23.8%) required revision surgery at a mean of 11.54 years (6.5 to 17 years); one required it for aseptic loosening of the femoral component; one required complete revision of the acetabular component; one required exchange of acetabular liner; and one was for symptomatic non-union of a lesser trochanter avulsion. This study shows encouraging clinical outcomes of custom made (CADCAM) Total Hip Arthroplasty in patients with osteochondrodysplasia,

Introduction. The treatment of trochanteric femoral fractures with the use of short femoral nails has become an established method. The fixation is required that lag screw be centered to prevent complications. But correct positioning of the device may difficult because of anatomical feature. This study evaluated the femoral morphology three-dimensionally using computed tomography (CT) images. Methods. Seventy eight patients (mean age 75)who underwent total knee arthroplasty were included. After three-dimensional reconstruction of the CT images, the anterior deviation from the femoral neck axis to proximal shaft axis was measured. The proximal shaft axis was defined as a line between center of the cross-section underneath the lesser trochanter and the center of diaphysis. The connection of center in narrow section of the neck and femoral head center was defined as neck axis. Results. The femoral neck axis and shaft axis were not coplanar. The anterior deviation of the axes was 7.5 mm (1.7 to 18.4 mm). The neck-shaft angle was 124° (110–142°). Discussion. Our results indicate that the nail and screw could not be center in current nail system, because of the non-crossing of the femoral axes. The large variation of neck-shaft angle would lead error in preoperative planning using traditional 2-D template system. Our study suggests needs for three-dimensional template system and newly femoral nail device

Objective. To three-dimensionally reconstruct the proximal femur of DDH (Developmental dysplasia of the hip) and measure the related anatomic parameters, so that we could have a further understanding of the morphological variation of the proximal femur of DDH, which would help in the preoperative planning and prosthesis design specific for DDH. Methods. From Jan.2012 to Dec.2014, 38 patients (47 hips) of DDH were admitted and 30 volunteers (30 hips) were selected as controls. All hips from both groups were examined by CT scan and radiographs. The Crowe classification method was applied. The CT data were imported into Mimics 17.0. The three-dimensional models of the proximal femur were then reconstructed, and the following parameters were measured: neck-shaft angle, neck length, offset, height of the centre of femoral head, height of the isthmus, height of greater trochanter, the medullary canal diameter of isthmus(Di), the medullary canal diameter 10mm above the apex of the lesser trochanter(DT+10), the medullary canal diameter 20mm below the apex of the lesser trochanter(DT-20), and then DT+10/Di, DT-20/Di and DT+10/DT-20 were calculated. Results. There is no significant difference in neck-shaft angle between Crowe I-III DDH and the control group, while the neck-shaft angle is much smaller in Crowe IV DDH. The neck length of Crowe IV DDH is much smaller than those of Crowe I-III DDH. As for Di there is neither significant difference between Crowe I DDH and the control group, nor significant difference between CroweII-III and Crowe IV, but the difference is significant between the first two groups and the latter two groups. DT+10/DT-20 and the offset have no significant difference between the control group and DDH groups. DT-20, DT+10, DT+10/Di and DT-20/Di are much smaller in Crowe IV DDH than that in Crowe I-III and the control groups. Height of greater trochanter in Crowe IV is larger than those in Crowe I-III and the control group. Height of the centre of femoral head in Crowe IV DDH is smaller than those in Crowe I-III DDH and the control group. The height of the isthmus in Crowe IV is much smaller than those in Crowe I-III DDH and the control group. Conclusion. The neck-shaft angle in DDH groups is not larger than that in the control group, while in contrast, it's much smaller in Crowe IV DDH than that in the control group. Comparing to Crowe I-III DDH and the control group, Crowe IV DDH has a dramatic change in the intramedullary and extramedullary parameters. The isthmus and the great trochanter are higher and there is apparent narrowing of the medullary canal around the level of the lesser trochanter

Introduction. Dual-mobility (DM) liners provide increased range of motion and stability. However, large head diameters have been associated with anterior hip pain due to impingement with surrounding soft-tissues, particularly the iliopsoas. Further, during hip extension the liner can get trapped due to anterior soft-tissue impingement that resists rotation being imparted to the liner from posterior stem-liner contact. Over time this can cause liner rim damage, leading to intra-prosthetic dislocation of the small diameter inner head. To address this, an anatomically contoured dual mobility (ACDM) liner was designed to reduce the volume of the liner below the equator that can interact with soft-tissues (Fig. 1). In this study, we utilized finite element analysis to evaluate tendon-liner contact pressure and tendon stresses with ACDM and conventional designs during hip extension, wherein the posterior edge of liner is in contact with the stem while the anterior edge is exposed to the soft-tissue. Methods. The average uniaxial stiffness (350 N/mm), and average dimensions (width × thickness = 14mm × 4mm) of 10 cadaver psoas tendon samples were determined in a separate study. The iliopsoas tendon was modelled as a Yeoh hyper-elastic material, and the material constants were tuned to match the experimental uniaxial test data. Cadaver specific FEA models were created for 5 specimens (10 hips) using computed tomography (CT) scans. The implant components were modeled as being rigid relative to the iliopsoas tendon. The iliopsoas tendon was modelled as extending from its insertion point on the lesser trochanter to the psoas notch on the pelvis for hip flexion angles of −15°, 0°, 15° and 30°. Appropriately sized DM components were implanted virtually for each specimen. Once placed in its proper position, the liner was rotated about the flexion axis until it contacted the stem posteriorly to represent its orientation during hip extension (Fig. 2). A 500N tensile load was applied to the iliopsoas tendon and the average/max stresses within the tendon, and average/max contact pressures between the tendon and liner were measured. Results. At all hip flexion angles from −15° to 30°, the tendon-liner contact pressure and tendon stresses were lower with the ACDM liners compared to the conventional liner. Contact pressure and tendon stress decreased for both liner designs with increasing hip flexion angle. At −15° flexion angle, the average contact pressure was 42.3% lower (0.36Mpa), and the maximum contact pressure was 45.1% (8.5Mpa lower), with the ACDM compared to conventional liner design. Similarly, at −15° flexion angle the average vonMises pressure in the tendon was 32.5% lower (14.8Mpa), and the maximum vonMises stress in the tendon was 55.7% (159Mpa lower) with the ACDM design. (Fig 3). Discussion. This study utilized cadaver specific FEA models to evaluate interaction between the iliopsoas tendon and conventional and ACDM liners during hip extension. The results showed a notable reduction in contact pressure and tendon stress resulting from reduced volume and more soft-tissue friendly profile of the ACDM design. Thus, the ACDM design may be able to reduce undesirable soft-tissue interaction with dual mobility liners

Introduction. Since 1989 we have been using custom lateral-flare stems. Using this stem, its lateral flare can produce high proximal fit and less fit in distal part. Applying this automatic designing software to the average femoral geometries, we can make off the shelf high proximal fit stem (Revelation ®). Putting the off the shelf stem, the original center of the femoral heads were well reproduced. But in DDH cases, severe deformities around hip sometimes make complicated difficulty for better functional reconstruction. They are high hip center such as Crowe II-IV, shortening of the femoral neck, high anteversion etc. DDH cases are well known to have higher anteversion than non DDH cases. There would be no definite explanations for it. The high anteversion would not always be harmful for the preoperative patients. But in some cases, osteophytes are observed at posterior side of the femoral head which make another sphere with different centre. We can guess that the patient's biomechanics had not been matched with the original anteversion. Then posterior osteophytes can correct inappropriate anteversion (self-reduction.) (Fig.1) In those patients, reduction of the anteversion by putting stems twisted into the canal or using modular stems are sometimes done by the surgeons' decision. Younger DDH cases can also be treated with THA, because of the complicated deformities or biomechanical disorders. Short stems are expected to reduce operative invasion and stress shielding then can reserve bone quality and quantity. From these point of view to improve the understanding of the characteristics of the DDH anteversion, and design a DDH oriented short stem could be one of good solution for those cases. Method. For the better understanding of the high anteversion 57 femora (mean anteversion: 34.4 deg.) were analyzed slice by slice. The direction of femoral head centre, lesser trochanter (LTR), linea aspera (aspera) just below LTR, aspera in the middle of the femur and aspera between the last 2 sections. All of the directions were assessed from PC line. To clarify the meaning of the head osteophytes, 35 operated cases were analyzed the extent of the head osteophytes. According to the results, a DDH oriented short stem was designed. Results. Even with the different anteversion, femoral head centres and LTRs were located within limited angle (51.4 +/−7.9 deg.) But aspera just below the LTR had no relation to the LTR direction, but always kept within limited angle (102.0 +/− 4.5) to the PC line. This means that DDH cases have proximal femurs of normal shape. But they are only twisted around the level just below the LTR. From this result, stems for DDH cases can have the same shape with normal stem inside the canal. The posterior osteophytes had reduced 4.6+/− 3.0 degree in average independently to the extent of anteversion. There was no tendency that higher anteversion cases have higher self-reduction angle. the stems were give the same shape inside the canal with stems for non DDH cases but its femoral head center was located with 5 degrees less anteversion

Introduction. To minimize leg length discrepancies (LLD), preoperative measures are taken using the PACS; the head center to the proximal end of the lesser trochanter distance (HLD) of the opposite side of the operating limb are calculated, while during operation, the modular neck selection is adapted to equal the opposing limb's length. The purpose of this study was to see whether the HLD method would show far less occurrences of LLD, in comparison to the conventional method(preoperative templating and shuck test). Method. 349 (412 hips) patients who had undergone THRA were divided into two groups based upon which methods they had used to equalize limb length during operation: (1) HLD method, and (2) conventional methods. Six months after surgery, using the PACS system, LLD's of the two groups were compared. Results. The mean postoperative LLD was 2.6±4.2 (0–15) mm in the HLD group and 5.2±7.0 (0–23) mm in the conventional group. In the HLD group, 81% (174/215) of the hips had LLD < 6 mm after surgery versus 72% (141/197) of the hips in the conventional group (P < 0.038). The mean Harris hip score (HHS) after THA improved from 47.2 to 93.3 in the HLD group and 46.8 to 91.8 in the conventional group. Discussion. Statistically, there was a significant difference of LLD between the two groups (p=0.038). HLD method, which is non-invasive and simple, would minimize LLD after total hip arthroplasty

Fractures of the proximal femur at the level of the lesser trochanter (reversed and transverse fracture lines, Evans classification type II, AO classification A3 fractures) are known to have an increased risk of fixation failure. 58 patients with such a fracture were randomised to have the fracture fixed with either an intramedullary nail (220 mm Targon PF nail) or a sliding hip screw (SHS). The mean age of the patients was 82 and 11% were male. All patients were followed up for one year by a research nurse blinded to the treatment groups. Mean length of surgery was 50 minutes for the nail versus 52 minutes for the SHS. There were no differences between groups in the need for blood transfusion. Operative complications tended to be less for the nail group (1/27 versus 5/26). Mean hospital stay was 18 days for the nail group versus 29 days for those treated with the SHS. The only fracture healing complications were one case of cut-out in the SHS group and two cut-outs in the nail group, two of which required revision surgery. During follow-up those patients treated with the nail reported a tendency to lower pain scores than those treated with the SHS (p=0.04 at two months). This difference persisted even at one year from injury. Mortality and regain of mobility was similar between groups. These results indicate that for these difficult fractures types both types of fixation produce comparable outcomes

PURPOSE OF THE STUDY. To assess if prolonged use of Bisphosphonates in Osteogenesis Imperfecta alters the pattern of femoral fractures. Osteogenesis Imperfecta (OI) has been treated with Bisphosphonates for many years with some clear clinical benefits. In adult cohorts there are reports of a new pattern of atraumatic subtrochanteric fractures seen with Bisphosphonate treatment. SUMMARY OF METHODS. This study assesses the location of femoral fractures in a cohort of 176 OI patients treated with Bisphosphonates over a two year period and compares it to a historical control group of 45 managed prior to the advent of this specific treatment. SUMMARY OF RESULTS. review of the radiological digital archive identified 16 femoral fractures in this time period in the Bisphosphonate treated group. All but 2 were within 5cm of the lesser trochanter, and 50% within 3cm. In comparison, the historical group, composed of 26 femoral fractures had a more widespread fracture pattern with the most frequent location being the mid-diaphysis. Many of the sub-trochanteric fractures in the treatment group occurred with minimal trauma, and in some cases without any injury. CONCLUSION. It appears that concerns in the adult osteoporotic population treated with Bisphosphonates are mirrored in Osteogenesis Imperfecta. It is possible that the high bending moments in the proximal femur together with altered mechanical properties of cortical bone secondary to the use of this group of drugs, mediated by abnormal osteoclast and osteoblast function, increase the risk of this type of injury and warrants further investigation

There is no mathematical relationship between the internal diameter of the femoral metaphysis and diaphysis. Unless an infinite number of monolithic stems are available with variable metaphyseal and diaphyseal diameters, which is not economically possible, even in virgin cases, the surgeon has to decide if the stem is going to fit in the metaphysis or the diaphysis. It is not possible to match both. In revision cases with a hollowed out metaphysis, the situation is much worse. As it is obviously easier to fit the diaphysis, this is what stems such as the AML and Wagner stem have done. They completely ignore the metaphysis and obtain fixation in the diaphysis. This is all well and good, but it means that the proximal femur is unloaded, like an astronaut in space. While, there will be some recovery due to removal of the toxins and local muscle pull, it will be incomplete. Furthermore, should sepsis occur, one is faced with the horror of removing a distally fixed implant. Clearly, if proximal fixation, i.e. above the level of lesser trochanter could reliably be achieved, this would be preferable in terms of proximal loading leading to bone recovery and ease of removal should it be required. The only way that proximal loading can be achieved is if the metaphyseal and diaphyseal parts of the component can be varied infinitely. This clearly can only be achieved by using a modular stem. The concern with modularity always has been fretting at the sleeve-stem locking mechanism with release of metal ions. The stem, which I have been using for the last 25 years, is the SROM stem. Fretting and ion release had never been an issue. As the components are made of a relatively soft titanium alloy, it is likely that the sleeve and the stem cold weld, thus, eliminating any movement and eliminating friction. I have a follow-up of roughly 120 revision cases with a minimum follow-up of 5 years and a maximum follow-up of 22 years. I have no loosening in easy revision cases where a primary stem was used. I have had some loosenings in extremely difficult revision situations where a long bowed stem was required, but even then, the loosening rate is less than 3%. I use this stem in primary situations, i.e. in about 80% of all the primaries I have done. This means I have done roughly 1500 cases or more. Other than some late infections, I have never, ever had any stem loosening in a simple case. Obviously, I have had loosenings in some cases, where we have been doing fancy shortening or de-rotation osteotomies, but none in simple primary cases. I would, therefore, suggest that the surgeon, if he wishes to use this stem, please try it out on some simple primary cases. The ability to vary distal and proximal internal diameters and proximal geometry makes for easy surgery. I have been using this stem for 25 years and continue to use it in all my primary noncemented cases. I believe in the adage of “train hard and fight easy.” I think that surgeons should not get themselves into a situation where they are forced in a difficult case to use something they have never seen before

Our aim was to assess the local extent of osteocyte death in the proximal femur of 16 patients with osteonecrosis of the femoral head. We performed histological examination of the femoral heads and cancellous bone biopsies from four regions of the proximal femur in patients undergoing total hip arthroplasty. A control group consisted of 19 patients with osteoarthritis. All histological specimens were examined in a blinded fashion. Extensive osteonecrosis was shown in the proximal femur up to 4 cm below the lesser trochanter in the group with osteonecrosis. There was an overall statistically significant difference in the extent of osteocyte death distal to the femoral head between the two groups (p < 0.001). We discuss the implications of these findings as possible contributing factors in regard to the early failure of total hip arthroplasty reported in patients with osteonecrosis of the femoral head

Aims

Traditionally, total hip arthroplasty (THA) templating has been performed on anteroposterior (AP) pelvis radiographs. Recently, additional AP hip radiographs have been recommended for accurate measurement of the femoral offset (FO). To verify this claim, this study aimed to establish quantitative data of the measurement error of the FO in relation to leg position and X-ray source position using a newly developed geometric model and clinical data.

Our study describes the mid-term clinical results of the use of transtrochanteric valgus osteotomy (TVO) for the treatment of osteoarthritis of the hip secondary to acetabular dysplasia. The operation included valgus displacement at the level of the lesser trochanter, and lateral displacement of the greater trochanter by inserting a wedge of bone. We reviewed 70 hips. The mean age of the patients at operation was 44 years (14 to 59). Most (90%) had advanced osteoarthritis. The scores for pain and gait had improved significantly at a mean follow-up of 9.4 years. The rate of survival until an endpoint of a further operation during a follow-up of ten years was 82%. The survival rate was 95% in patients with unilateral involvement who were less than 50 years of age at operation. TVO is a useful form of treatment for advanced osteoarthritis of the hip, particularly in young patients with unilateral disease

Fracture classification of femoral trochanteric fracture is usually based on plain X-ray. However, complications such as delayed union, non-union, and cut out are seen in stable fracture on X-ray. In this study, fracture was classified by 3D-CT and relationship to X-ray classification was investigated. 48 femoral trochanteric fractures (15 males, 33 female, average age: 82.6) treated with PFNA-II were investigated. Fracture was classified to 2part, 3part(5 subgroups), and 4part with combination of 4 fragments in CT; Head (H), Greater trochanter (G), Lesser trochanter (L), and Shaft (S). 5 subgroups of 3 part fracture were (1) H+G (S: small fragment) + L-S, (2) H + G (B:big fragment) + L-S, (3) H + G-L + S, (4) H + G (W:whole) + S, and (5) H + L + G-S. Numbers of each group were as follows; 2 part: 11, 3 part (1) : 7, 3 part (2) : 12, 3 part (3) : 10, 3 part (4) : 2, 3 part (5) : 3, 4 part : 3. 3 part (3), (4), (5) and 4 part are considered as unstable, however, 6 cases in these groups were classified in A1–1 or A1–2 stable fracture in AO classification. 10 fractures in Evans and 5 fractures in Jensen classification classified as stable were unstable in CT evaluation. It is sometimes very difficult to classify the femoral trochanteric fracture by plain X-ray. Classification with 3D-CT is very useful to distinguish which fracture is stable or unstable

Introduction. Total hip arthroplasty (THA) for a highly dislocated hip can be problematic and technically challenging. Our previous study on cemented THA with subtrochanteric femoral shortening osteotomy revealed a high incidence (20%) of non-union. Therefore, in 2008, we introduced reverse hybrid THA using S-ROM stem for the treatment of a highly dislocated hip. The purpose of this study was to assess the short-term clinical outcomes of this new method. Patients and methods. Between 2008 and 2014, 13 consecutive reverse hybrid THAs were performed on nine female patients with highly dislocated hips. The average age at the time of operation was 66 years (range, 55–85 years). The acetabular component was fixed in the true acetabulum with bone cement. Transverse osteotomy was performed below the lesser trochanter to shorten the femur and to prevent over-lengthening. The proximal sleeve of the S-ROM stem was then fixed within the proximal fragment, and the distal fin provided rotational stability of the distal fragment. Thus, the two fragments were fixed to each other with the S-ROM stem, and the resected segment was longitudinally cut for grafting at the junction. The postoperative follow-up period was an average of 4 years (range, 1–7 years), and no patients were lost. Preoperative and final Japanese Orthopaedic Association (JOA) hip score, operation time, bleeding amount, intraoperative and postoperative complications, bone healing at the osteotomy site, implant loosening, and revision surgery were retrospectively investigated. Results. The mean JOA hip score improved from 56 points preoperatively to 82 points postoperatively. The operation time and amount of bleeding were an average of 208 min and 643 g, respectively. The mean length of femoral resection was 4 cm (range, 2–6 cm), and the tip of the greater trochanter migrated an average distance of 7 cm (range, 5–9 cm) distally. The calculated limb lengthening was an average of 3 cm (range, 2–4 cm). Intraoperative fracture was seen in two patients, but no repeat operation was required. Two patients experienced postoperative dislocation in their hips, but additional surgery was not necessary. Postoperative nerve palsy did not occur in any patient, and all the osteotomy sites showed complete bone union. There was no implant loosening seen in any patient, and there was also no need for revision surgery. Discussion and conclusions. To achieve satisfactory outcomes with this method, resection of necessary and sufficient length of femur and accomplishment of adequate fixation between the proximal and distal fragments are necessary. In this study, dislocation occurred in two patients, and no nerve palsy was seen. Larger femoral heads may be recommended to eradicate dislocations. In cases where metaphysis of the femur is hypoplastic or the medullary canal is wide, reaming and stem insertion should be carefully performed. In this series, no additional surgery was required for the intra- and post-operative complications, and the osteotomy sites achieved bone union in all patients. Therefore, we recommend the use of this method, although longer follow-up periods are necessary

INTRODUCTION. Mechanical tissue properties of some ligaments and tendons have been described in the literature. However, to our knowledge no data exists describing the tensile properties of the Iliopsoas tendon. The iliopsoas complex is in very close proximity to the hip joint running through the psoas notch from the inner side of the pelvis to the lesser trochanter on the posterior aspect of the proximal femur. The tendon muscle complex wraps around the anterior aspect of the femoral head. Hip joint intervention such as total hip arthroplasty (THA) can interfere with iliopsoas function and contact mechanics, and thereby play a major role in the clinically known condition of anterior hip pain. For computer simulations such as finite element analysis (FEA) precise knowledge of soft-tissue mechanical properties is crucial for accurate models and therefore, the goal of this study was to describe the iliopsoas tensile properties using uniaxial testing equipment. METHODS. Ten iliopsoas tendons were harvested from five specimens (2 male, 3 female; 82.4 yrs ±7.4 yrs) and then carefully cleaned from any fat and muscle tissue. Two freeze clamps were fixed to each end of the tendon sample. The clamps were submerged in liquid nitrogen for 30 seconds to prevent tendon slip and attached to the test frame and load cell via carabiners allowing the tendon to rotate around its long axis. Width, thickness and initial gauge length of each tendon were measured before testing. The test protocol included 10 cycles of preconditioning between 6 N and 60 N at 0.4 mm/s, followed by continuous distraction at 0.4 mm/s until failure. For each tendon the linear stiffness was determined by fitting a straight line to the liner region on the force-displacement curve (Fig. 1). RESULTS. The average linear stiffness of the ten iliopsoas tendons was measured to be 339 N/mm ±81 N/mm and the average failure load resulted in 2154 N ±418 N (Fig. 2). Average width and thickness were determined to be 13.9 mm ±3.2 mm and 3.8 mm ±0.5 mm respectively. The initial gauge length of the ten tendons revealed an average of 56.5 mm ±10.5 mm. CONCLUSION. An average stiffness of 339 N/mm and average failure load of 2154 N was found in our experiments. A trend of increased stiffness and reduced failure load with higher age could be observed. Soft-tissue mechanical properties are dependent on tissue geometry such as cross-sectional area and length and therefore can be variable in comparison with other anatomical structures (e.g. patella tendon). To our knowledge no data has been published on the mechanical properties of iliopsoas tendons and therefore results from this research could be used for future simulation models involving the iliopsoas tendon such as FEA analysis to evaluate the effect of anterior hip pain due to soft-tissue impingement

Fractures of the proximal femur at the level of the lesser trochanter (reversed and transverse fracture lines, Evans classification type II, AO classification 31. A3 fractures) are known to have an increased risk of fixation failure. 53 patients with such a fracture were randomised to have the fracture fixed with either an intramedullary nail (220 mm Targon Proximal Femoral nail) or a Sliding Hip Screw (SHS). The mean age of the patients was 82 and 11% were male. All patients were followed up for one year by a research nurse blinded to the treatment groups. Mean length of surgery was 51 minutes for the nail versus 53 minutes for the SHS. There were no differences between groups in the need for blood transfusion. Operative complications tended to be less for the nail group (1/27 versus 5/26). Mean hospital stay was 17 days for the nail group versus 29 days for those treated with the SHS (p< 0.0001). The only fracture healing complications were one case of cut-out in each group requiring revision surgery. During follow-up those patient treated with the nail reported significantly lower pain scores than those treated with the SHS (p=0.08). This difference persisted even at one year from injury. In addition there was a tendency to a better regain of mobility in the first nine months from injury for those treated with the nail. These results indicate that for these difficult fractures types an intramedullary nails produces superior results to the Sliding Hip Screw

Introduction: Femoral offset plays an important part in the biomechanics of the hip with inaccurate balancing at the time of arthroplasty leading to abductor weakness, leg length discrepancies and altered wear characteristics. Aim: To look at the degree of external rotation of the leg at the time of pre-operative x-rays and to assess the effect of this on templating for femoral offset. Methods: A radiological review of a cohort of patients attending for hip arthroplasty with unilateral osteoarthritis. Results: Externally rotated posturing of the affected leg is common amongst patients with osteoarthritis attending for hip arthroplasty. The effect of this change in the positioning of the femoral neck is to create an apparent reduction in the offset of the femoral shaft. This will lead to underestimation of the correct offset for the chosen prosthesis. In over 50% of cases templating would have been incorrect. Conclusions: When templating prior to hip arthroplasty surgery an assessment of the profile of the lesser trochanter will give an impression of the leg position. If this is externally rotated it should be presumed that the offset will be larger than the measured value. If the other hip is in a better rotational position this should be used for assessment

Hereditary multiple exostoses is an autosomal dominant disorder characterised by multiple osteochondromata, most commonly affecting the forearm, knee and ankle. Osteochondromata of the proximal femur have been reported to occur in 30% to 90% of affected patients with coxa valga in 25%. Acetabular dysplasia is rare but has been described. This is the first report of a patient requiring surgical intervention. A girl was seen at the age of nine with hereditary multiple exostoses and when 12 developed bilateral pain in the groin. Radiographs showed severely dysplastic acetabula with less than 50% coverage of the femoral heads and widening of the medial joint space. Large sessile osteochondromata were present along the medial side of the femoral neck proximal to the lesser trochanter, with associated coxa valga. The case illustrates the importance of obtaining initial skeletal surveys in children with hereditary multiple exostoses to identify potential problems such as acetabular dysplasia and subluxation of the hip

Comminuted subtrochanteric fractures pose a clinical challenge; locking plate technology has been theorized to offer treatment advantages. A comminuted subtrochanteric femoral fracture model was created with a 2 cm gap below the lesser trochanter in fifteen matched pairs of human cadaveric femora confirmed to be non-osteoporotic. The femora were randomized to treatment with a trochanteric femoral nail (TFN), proximal femoral locking plate (PFLP), or 95° angled blade plate (ABP). Each was tested under incrementally increasing cyclic load up to 90,000 cycles to simulate progressive weight bearing during three months. The TFN was the strongest implant: it withstood significantly more cycles, failed at a significantly higher force, and withstood a significantly greater load than either plate (p< 0.001). Varus collapse was significantly lower in the TFN construct (p< 0.0001). Mode of failure differed among implants, with damage to the femoral head through implant cut-out in five of ten blade plate specimens and two of ten nail specimens, whereas no damage to the femoral head bone was observed in any of the PFLP specimens. The TFN was biomechanically stronger than the PFLP and this may have clinical relevance during the slow healing of subtrochanteric femoral fractures. The PFLP was biomechanically equivalent to the ABP but failure occurred without significant damage to the femoral head, suggesting that although biomechanically equivalent, the PFLP might have clinically relevant advantages in its mode of failure over the ABP

Aims

This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged less than 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component.

Purpose of the study: Radiographs of 24 patients who underwent surgery for total hip arthroplasty (THA) with a locked stem were reviewed at 38 months mean follow-up using a dedicated software. This software enables digital analysis of standard radiographs with semiquantitative evaluation of bone density. Material and method: Good quality postoperative AP views of the femur and the same view at last follow-up were selected using the same criteria. These images were digitalised then analyses with the software. Bone density was established along a horizontal line 1 cm below the lesser trochanter perpendicular to the femur shaft. Computer analysis of bone density established three categories of patients as a function of cortical density: no cortical modification (n=5 hips), modification of only one cortical (n=11) and modification of both corticals (n=8). Results: Bone density increased, suggesting improve cortical bone stock as has been reported by most authors using the transfemoral approach and a non-cemented locked stem. Discussion: This result confirms the data in the literature; data which, unlike our series, were established on qualitative or subjective evaluations. The method presented here has the advantage of a semi-quantitative analysis, simple use, applicable to plain x-rays, and good reproducibility since all measures are made by the software. This study demonstrated the notion of cortical quality since it was not limited to a simple measurement of width, but also bone density, closer to real intraoperative observations. Conclusion: Use of this method enables longitudinal study to establish the kinetics of bone remodelling, compare results between surgical methods, and search for factors explaining observed variations

Ten uncemented total hip replacements were performed in 1975 using an implant in which the cobalt-chrome femoral stem was coated to give a porous surface. In all but one case a high-density polyethylene head was used. The radiological changes in the upper femoral shafts were assessed between three and nine years later. Seven showed extensive stress-relieving changes, loss of calcar, stress fractures at the root of the lesser trochanter with subsequent detachment, and osteoporosis followed by avulsion of the greater trochanter. In these seven patients the lower part of the stem appeared to be soundly embedded, although in only one was there evidence of bony incorporation. It is suggested that if the fixation of a fully coated implant of this sort remains sound, gross atrophy of the upper femoral shaft develops after five years. This atrophy, associated with an implant which can be removed only at the expense of further bone destruction, presents substantial problems if revision is needed

1. If a vertical load is applied to the head of the femur parallel to its shaft, the upper cortex is stretched and the lower cortex is compressed. The neck breaks from the upper subcapital border to the lesser trochanter. This type of fracture is rarely found clinically. 2. If a compressive force is applied to the area between head and greater trochanter while the head is loaded vertically, a transverse fracture of clinical appearance is produced. If this axial pressure acts along the part of the neck above the central axis a subcapital comminuted fracture results. If the pressure acts below the central axis the result is a transcervical fracture. 3. Strain gauge experiments have shown that axial compression within the upper segment of the neck is produced by the abductor muscles of the hip. Adductor muscles produce a low axial compression. It is suggested that muscular action at the time of injury influences the type of fracture produced by the injury

Introduction. Excellent long-term survival rates associated with the absence of stem subsidence have been achieved with total hip arthroplasty (THA) using femoral components cemented line-to-line (“French Paradox”). Recently, short stems have been introduced in order to preserve diaphyseal bone and to accommodate to minimal invasive THA and a variety of clinical situations. The aim of the current study was to quantify the rotational and tilting stability of a Kerboull stem of varying length after line-to-line cementation using a validated in-vitro model. Materials & methods. The femoral component made of M30NW stainless steel was derived from the original Kerboull stem. It had a double taper, a highly polished surface, and a quadrangular cross-section. Four stem lengths were designed from the original length with a distal reduction of 6, 12, 17 and 22%, whereas the proximal body geometry of the implant remained unaffected. For each stem length, five specimens were implanted into a non-canal synthetic femoral model. The femoral preparation was performed in order to obtain rotational and tilting stability of the stem prior to the line-to-line cementation. Spatial micro-motions of the specimens were investigated using a validated rotational measuring set-up. In addition, in a second separate step, the specimens were exposed to a ventro-dorsal moment to mimic varus-valgus moment. Statistical analysis was performed using ANOVA with Fisher PLSD. Results. The maximum torque transfer from the stem within the cement mantle to the composite femur occurred at the level of the lesser trochanter, whereas the lowest torque transfer was observed at the tip of the stem. The relative movement at the tip was significantly greater for the original length when compared to 6 and 12% length reduction (p = 0.036 and 0.033, respectively). The 12% reduction resulted in a significant lower mean overall movement when compared to the original length (p = 0.044). The tilting behavior according to the stem lengths indicated that proximal bending value was significantly increased for 17% reduction when compared to 6% and 12% reduction (p = 0.035 and 0.032, respectively). Bending of the tip of the stem was in the same direction as the shoulder, indicating a backlash from the tip. At the tip, relative bending was increased when compared to the previous length up to 12% reduction and then decreased. However, the difference was not significant (p <0.05). Discussion & conclusion. The stem lengths evaluated in the current study showed similar results to previously reported cemented stems of different designs, indicating a close fixation to composite bone with small relative movement. Both 6 and 12% shortened versions showed significant reduced relative movement at the tip when compared to the original length, suggesting a limited role for the tip in terms of rotational stability. Regarding the medio-lateral torque, the stems always reacted with a backlash and did not tilt like a rigid body. Although not significant, the distal bending tended to increase with reduced length. These findings led us to develop a Kerboull stem with 12% distal reduction that is currently under clinical trial

Purpose. The hip region is the second most common site for tuberculosis following the spine in children. The aim is to describe the variable radiological patterns of presentation and their resemblance to pyogenic infection, tumours and other benign conditions of bone in children. Methods. The clinical and radiological records of 29 children aged 10 months–13 years with confirmed tuberculosis of the hip region seen between 1990 and 2011 were reviewed retrospectively. Clinical features were pain, limp and flexion, adduction contractures. Abscesses and sinuses were seen in 4 children. The ESR ranged between 7–110 mm/hr. Mantoux was positive in 20 children. All cases were histologically confirmed. Treatment involved biopsy, currettage of bone defects, limited synovectomy and adductor tenotomy. Patients were immobilised for 4 weeks on a spica cast or traction. Antituberculous treatment was administered for 9–12 months. Results. Radiologically 9 lesions were extra-articular and 20 involved the joint synovium and articular surface. Extra-articular lesions were seen in the pubis, greater and lesser trochanter, ilium, proximal femur and peri-acetabular regions. Intra-articular lesions were seen in the femoral head, neck and acetabulum. Dislocations and subluxations occurred in 8 patients; various lesions mimicked pyogenic arthritis, idiopathic chondrolysis, chondrobastoma, Perthes disease, eosinophilic granuloma and osteoid osteoma. Follow up ranged between 8 months and 5 years. Good range of movement was seen in 20 children. Nine children had flexion adduction contractures, four of these had ankylosed hips and five required abduction extension osteotomies. Other changes seen were coxa vara (2) coxa magna (1) and avascular necrosis (3). Conclusion. The variable radiological picture of tuberculosis of the hip region can mimic various osteoarticular conditions in children. Biopsy is essential and should be taken from the bony lesion and not the synovium alone. NO DISCLOSURES

One of the ironies in modern technology for arthroplasty is the stress shielding in cementless stems. The aim of the development of cementless stems had been reduction of stress shielding which cement stems are not free from. In healthy femur, trabecula start form the femoral head and reach at both medial and lateral cortex in rather narrow area around lesser trochanter. So the load from the femoral head is transferred at the level on both medial and lateral side. Cement stems should have binding to the cortical bone from collar to the tip of the stem where the cement interlays, and then the load is transferred gradually from the tip to the collar, which means mild stress shielding. When distal bonding is removed, the load could be transferred as normal femur. This should have been one of the biggest requests for cementless stem. But in realty many cementless stems have difficulty to obtain a load transfer at the level like normal femur. Since 1990, we have been mainly using lateral flare stems to obtain contact on both medial and lateral side at proximal level. In the present study, different types and length of the designs were compared by 3-Dimensional fill, 3-Dimensional fit and Finite Element Analysis. Materials and Methods. Stems from DJO: Revelation Standard, Revelation Short, and Linear stems were inserted into patients' canal geometries. Three-D fill and 3-D fit which were reported ISTA2009 and stress transfer were observed by FEA. Results. The closest fit and fill were observed Revelation Short and Revelation Standard then Linear. The most proximal load transfer was observed Revelation Short, followed by Revelation Standard then Linear

Aims

The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the ‘French paradox’ principles through the Hueter anterior approach (HAA) in patients older than 70 years.

Introduction: Since 2000 all total hip replacements have been subjected to a continuous quality control. We report an increasing rate of postoperative fractures around uncemented femoral components after minimal or no trauma. Methods: Four to 6 weeks after the THR all patient files and radiographs are evaluated and demographic data, complications and radiographic position of the implant registered. Surgery was performed according to the manufacturer’s instructions, and full weight bearing was allowed. If a fracture occurred during the first postoperative weeks a further analysis of the case was performed. Results: During the 9 years 3.295 primary total hip replacements were performed. In the period the use of uncemented THR increased from 41% to 99%. Totally 69 fractures in 2.408 uncemented THR’s (2.9%) were registered, and 28 of these were of the proksimal split fracture type occurring without any previous trauma. The fractures occurred after a few days up to 4 weeks after surgery and were characterised by a vertical femoral fracture from the calcar to the medial femoral region 5 to 7 cm below the lesser trochanter. All cases were seen in women, but were not correlated to age, BMI or previous femoral neck fracture. In most cases treatment was internal fixation with a trochanteric grip and cables and insertion of a new uncemented femoral component. Conclusion: The increased use of uncemented femoral components implies a substantial risk of subtrochanteric femoral fracture. The cause of these fractures is unknown, but probably multifactorial. It could be due to a mismatch between the instruments and the prosthesis, to undiagnosed weakness of the bone, or to the vigorous mobilisation made possible by the effective modern treatment of postoperative pain

We reviewed 19 patients who presented with aggressive granulomatosis around the femoral stem after hip replacement. All had experienced stress pain and had required revision arthroplasty on average 8.8 years after the primary operation. Fifteen patients were men and four were women; none had rheumatoid arthritis. One patient had an uncemented Moore hemiprosthesis; the others all had cemented total hip replacements. When first detected, the granulomatous lesions were multifocal in 13 patients. The first granuloma was in the region of the lesser trochanter in 10, and near the tip of the stem in only two. Speed of growth varied but on average there was doubling of the area on anteroposterior films in 2.2 years (range 6 months to 4.6 years). Aggressive granulomatous lesions in replaced hips are a distinct condition, different from simple loosening or infection; the lesions may grow rapidly, so revision surgery is indicated soon after diagnosis

Introduction. Dual-mobility (DM) liners have increased popularity due to the range of motion and stability provided by these implants. However, larger head diameters have been associated with anterior hip pain, due to surrounding soft-tissue impingement, particularly the iliopsoas. To address this, an anatomically contoured dual mobility (ACDM) liner was designed by reducing the volume of the liner below the equator (Fig1). Previous cadaver studies have shown that the ACDM significantly reduces iliopsoas tenting and trapping of the liner compared to conventional designs. We created a finite element study based on previous cadaver testing to further analyze the effectiveness of the ACDM design in reducing soft-tissue impingement, specifically the tendon-liner contact pressure and the tendon stress. Methods. The finite element model was developed within COMSOL 4.3b. The psoas tendon was modelled as a Yeoh hyper-elastic Material, which uses 3 constants (c1-c3), density (1.73g/cm3) and a bulk modulus (26GPa)[Hirokawa,2000]. In a previous, separate study, the average stiffness of 10 psoas tendon samples (5 cadavers), were measured to be 339[N/mm] in the linear region with average width and thickness of 14mmX4mm. The 3 constants were tuned to match experimental uniaxial test data, and were 5[GPa], 0[Gpa], and 46[GPa] for c1, c2, and c3 respectively. The implant components were rigidly modeled relative to the psoas. Cadaver specific CT models were used to create the FEA geometry. The insertion points for the Psoas were digitally determined on the proximal end of the lesser trochanter, and the psoas notch on the pelvis for hip flexion angles of −15°, 0°, 15° and 30°. These insertion points determined the length of the psoas and its relative position to the femoral head in 3D. The specific liner size and position for each cadaver was determined by implant planning with the CT models. In this abstract, we only present data for 2 specimens (left/right hips) with 44mm conventional DM, and 44mm ACDM, matching specimen anatomy. A 500N tensile load was applied to the psoas tendon proximally to simulate moderate physiological loading, the average/max stresses and contact pressures between the psoas and the two liner designs were determined. Results. At all flexion angles from −15° to 30°, the ACDM had lower psoas-liner contact pressure and stress compared to the conventional liner. Both contact pressure and tendon stress decreased for both liners with increasing hip flexion. At −15° flexion angle, there was an average contact pressure difference of .51MPa between the conventional and ACDM designs, or 37% decrease in pressure when using the ACDM. The average difference in tendon stress was 67.9MPa, or a 59% decrease in stress when using the ACDM (fig2, fig3). Conclusion. This study utilized cadaver specific FEA models to evaluate interaction between the iliopsoas tendon and conventional and ACDM liners. Although this abstract presented FEA models for only four hips (two specimens), the results show a notable reduction in contact pressure and tendon stress with ACDM designs. This validates findings from previous cadaver studies, suggesting that anatomically contoured designs could reduce anterior hip pain and soft tissue impingement

Introduction:. Demand for total hip arthroplasty (THA) continues to rise and as such there is a concurrent presumed increase in the incidence of periprosthetic femoral fractures. Several studies have previously demonstrated differences in fixation technique and biomechanical advantages of various cerclage constructs in fixation of femoral periprosthetic fractures. The purpose of this study is to determine the most effective combination of cerclage materials and technique in fixation of of periprosthetic fractures during cementless THA. Methods:. Thirty fourth generation synthetic femora were tested in axial compression and torsion. Femurs were placed in a standardized mount and a press fit hip prosthesis was implanted by one senior surgeon. After broaching but prior to implant placement, a band saw was used to create a Vancouver B1 fracture below the level of the lesser trochanter. The implant was then placed in the femur. Four different cerclage constructs were then created using two of the following: 1) hose clamp, 2) metallic cable, 3) synthetic cable, 4) monofilament wire. All cables were placed using tensioning devices to standardize final cerclage tension. Additional constructs were created increasing the number of cerclage cables/wires to three and then four, evenly spaced across the implant. Axial compression and torsion were assessed to failure for all constructs using standard Instrom testing criteria. Cost analysis was performed for each construct. Results:. Data suggests that Construct 1 demonstrated superior results in both axial compression and torsion in all trials, increasing with the number of clamps used. Construct 4 demonstrated inferior results in both axial compression and torsion, although increasing the number of wires significantly increased the strength of the construct. Construct 2 and 3 were equivalent. Conclusion:. Increasing the number of cerclage cables/wires significantly increases the strength of the construct in both axial compression and torsion. Overall strength in order of strongest to weakest is as follows: hose clamp, metallic cable, synthetic cable and monofilament wire. It is reasonable to consider monofilament wires as a viable fixation option given lower cost and overall strength at physiologic loads

Postoperative peritrochanteric pain, which can be caused by non-union of the greater trochanter in those who have undergone total hip arthroplasty (THA) with trochanteric osteotomy, affects patient satisfaction. We reviewed 89 consecutive cases of primary THA performed with a mini-trochanteric direct lateral approach (Wafer approach), during which the anteroinferior trochanteric fragment (2 cm × 1 cm) attached to the anterior one-third or one-fourth of the gluteus medius muscle insertion and the entire insertion of the gluteus minimus muscle were osteotomized and detached using a curved chisel for exposure, while the origin of the vastus lateralis muscle remained intact. After completion of implantation, the detached fragment was fixed in the original position using 2 parallel braided sutures. If returning the trochanteric fragment to its original position was difficult, the tightened posterior tendinous portion of the gluteus minimus muscle was released to reduce the fragment easily and was then fixed. The surgeries, which included 19 cemented, 7 cementless, and 63 hybrid THAs, were performed between January 2012 and August 2013, and the patients [13 men, 76 women; average age, 65.6 years (38–86 years)] were followed for 6 months. The original diagnosis included primary osteoarthritis in 7 cases, osteoarthritis secondary to dysplasia in 75 cases, and avascular necrosis of the femoral head in 7 cases. X-ray examination including anteroposterior (AP) and lateral hip views was performed at 1, 3, and 6 months postoperatively, and a displacement of > 5 mm of the osteotomized fragment in either the AP or lateral view was considered fragment migration. The Japanese Orthopaedic Association (JOA) pain score was also recorded at 3 and 6 months postoperatively. We examined the possible factors affecting trochanteric migration and JOA pain score, including age, sex, THA type, leg lengthening, Crowe classification, and suture type. We also examined the correlation between trochanteric migration and JOA pain score. There were no peri- or post-operative complications including infection, deep venous thrombosis, dislocation, or periprosthetic fracture. No revision or radiographic loosening occurred in the follow-up period. Average leg lengthening was 9.8 mm (−4–21 mm), measured on the AP X-ray of the hip as the vertical interval between the pre- and postoperative positions of the lesser trochanter. There were 35 cases (39.3%) of trochanteric migration at postoperative 3 months. The Chi-square test and logistic regression analysis indicated that age, sex, Crowe classification, leg lengthening, and suture type did not affect trochanteric migration or JOA pain score. On the other hand, THA type did not affect trochanteric migration but did affect JOA pain score at postoperative 3 months. Patients who underwent cementless THA had worse JOA pain scores than the other patients. There was no correlation between trochanteric migration and JOA pain scores. The results indicated that trochanteric fragment migration often occurred in this series using the Wafer approach. Although the pain score is affected by many factors including thigh pain, hip abductor weakness, and wound irritation in the short term, it did not correlate with the trochanteric nonunion rate of this approach

Background. Safety and efficacy of novel prostheses relies on the determination of early implant migration and subsequent risk of loosening. Radiostereometric Analysis (RSA) has been used to evaluate the clinical failure risks of femoral stems by reporting distal migration, a measure of stem subsidence, when examining early migration characteristics. The migratory patterns of femoral stems, 24 months postoperatively, have provided a surrogate outcome measure to determine implant stabilisation and predict long-term performance and survivorship. RSA assessed femoral stem migration and provided comparison of the early migration characteristics with published data of a clinically established counterpart. Methods. Twenty five patients undergoing primary total hip arthroplasty were implanted with a hydroxyapatite-coated femoral stem. The median age was 65 years (range, 43–75 years). During surgery tantalum markers were attached onto the distal tip and shoulder of the stem. Eight tantalum markers were inserted into the femur, four placed in each of the greater and lesser trochanter. RSA examinations were performed postoperatively at 4 to 5 days, 6, 12 and 24 months. Eleven patients who had complete RSA follow-up as well as the valid data from five patients were analysed to determine the movement of the femoral stem relative to the femur and were compared to the published data of a clinically established counterpart. Results. At 24 months the magnitude of migration of the femoral stem translations for the y axis of movement was 0.32 mm (range, 0.00 to 2.04 mm) (Figure 1). The data demonstrates that this migration of the femoral stem occurred primarily in the first 6 months postoperatively and that the migration characteristics exhibit a pattern of implant stabilisation between 6 and 24 months. At 24 months the magnitude of migration of the femoral stem rotations for the longitudinal y axis of movement was 0.60. o. (range, 0.08 to 2.08. o. ). The data demonstrates continuing migration of the femoral stem at 12 months postoperatively with early indications of implant stabilisation between 12 and 24 months. At 24 months the mean subsidence/distal migration of the femoral stem was 0.20 mm (range, −2.04 to 0.32 mm) (Figure 2). At 6 months, two patients (12.5%) exhibited subsidence greater than 0.50 mm with one demonstrating a mean subsidence of 2.00 mm. Between 6 and 24 months these two patients exhibited no more than 0.04 mm of subsidence (Figure 3). The mean retroversion rotation of the stem was 0.10. o. (range, −0.99 to 2.08. o. ). One patient rotated more than 2.00. o. into retroversion at 12 and 24 months postoperatively. Conclusions. In comparison the data demonstrates less stem subsidence and retroversion rotation than published data for a cementless hydroxyapatite-coated femoral stem when observing early migration characteristics. The magnitude and pattern of migration exhibited is indicative of good clinical outcomes and is comparable with a clinically established counterpart after short-term follow-up with RSA. These findings and comparisons highlight the early migration characteristics of a hydroxyapatite-coated femoral stem, however the analysis and comparison of the migratory pattern and characteristics over the mid-term follow-up will confirm implant stabilisation

Femoral components in total hip replacements fail in well-known ways. There is vertical sink, posterior rotation and pivot, either distal or mid-stem. In order to sink, the stem moves into valgus and then slides down the inside of the calcar. It does not cut through the calcar. To prevent sink and pivot, a canal filling stem is required. Canal fill prevents the stem from moving into valgus and, therefore, it will not sink. Two centimeters with complete canal fill is adequate in a primary stem. A long stem will give longer canal fill in a revision. Sharp distal flutes will prevent rotation. The distal end of the stem should be polished. One is looking for a distal stability, not distal fixation. If the isthmus is intact, a primary stem can be used. If the isthmus is damaged, a long stem is necessary. If the calcar is intact, a primary neck is adequate. If the calcar is missing down to the level of the lesser trochanter, a calcar replacement neck is required. If there is more than 70 millimeters of completely missing proximal femur, a structural allograft is required. If the proximal femur is damaged, the ability to place a sleeve or collar to seek the best bone available independently of the stem version is very helpful. No matter how poor the proximal bone quality is, it can be supplemented by cerclage wires. The implant will sink only if the cerclage wires break. The advantage of proximal fixation is that loading the proximal femur speeds recovery. The huge disadvantage of distal fixation is removal of the implant should it become necessary. My long term results for the S-ROM stem used in revision are now out over 20 years. There were 119 primary stems with a minimum follow up of 5 years with no revisions for aseptic loosening. There were 262 long stems used. Nine (3.7%) underwent aseptic loosening. Most of these were due to technical errors due to my inexperience in the learning process of revision surgery. Four were dependent on strut-grafts and should have been treated with structural allografts. There were seven cases with structural allografts. Three were revised. Again, these were largely from problems arising from inexperience. I believe proximal modularity with distal stability allows the vast majority of revision cases to be treated with proximal fixation

We examined data from a large prospectively collected dataset which followed up patients after Exeter total hip replacement (THR) - the Exeter Primary Outcome Study. We studied 78 patients who had total hip replacement for osteoarthritis on a morphologically normal hip, and in whom the other hip was also morphologically normal for comparison. All selected patients had complete patient outcome data at 1 and 5 years, and x-rays at 1 year were available. We measured accuracy of reconstruction on AP Pelvis radiographs. The parameters measured were difference in height of lesser trochanter from horizontal pelvic line (LLD); length from ASIS to greater trochanter (indicating abductor length, AL); length from symphysis to centre of femoral head (SFH); length from centre of head to axis of femur (offset). We examined clinical outcomes including gain of Oxford Hip Score (DOHS) at 1 and 5 years, absolute OHS at 1 and 5 years, and absolute SF-36 Physical Functioning and Role Physical scores at 1 and 5 years. Examining the ratios of AL, SFH, Offset, Offset to SFH ratio and LLD between side of THR and unaffected side all showed marked variation. Thus the ratio of SFH varied from 0.85 to 1.11. For further analysis we divided the patients into 3 groups on the basis of variability of the ratio from 1; we examined whether the clinical scores above varied between these 3 groups. 1 way ANOVA demonstrated no significant difference for any of the clinical outcomes for any of the 5 grouped x-ray variables. Accuracy of reconstruction has been shown to affect the risk of dislocation after THR. Our results indicate that clinical outcomes of total hip replacement appear resilient to some degree of surgical inaccuracy. Future trials of navigation should be designed to demonstrate not only improved accuracy but also improved clinical outcome

Classification systems are used for communication, deciding/planning treatment options, predicting outcome and research purposes. The vast majority of subtrochanteric fractures are now treated with intramedullary nails, which questions the need for classification. Our objective was to assess the intra- and inter-observer reliability of the Seinsheimer, AO and Russell-Taylor (RT) classification systems and assess a new simple system (KMG). The KMG system was developed to alert the surgeon to potential hazards: Type 1 – subtrochanteric fracture (ST#) with intact trochanters. Type 2 ST# involving greater trochanter (entry point for nailing difficulty). Type 3 –ST# involving lesser trochanter (most unstable). 32 AP and lateral radiographs of subtrochanetric fractures were classified independently by 4 observers twice with a 6-week interval (2 Consultants and 2 Registrars). The observers were asked to rank the systems based on how descriptive they thought they were, whether they felt they influenced treatment plan and whether they would predict outcome. The intra- and inter-observer variation was poor in all systems. KMG gave the best inter-observer reproducibility (Kappa 0.3 to 0.6) followed by AO and RT, and then Seinsheimer. The observers felt that Seinsheimer and KMG were the most descriptive and would influence the treatment plan, and Russell-Taylor would perform worst at predicting outcomes. All of the fractures in this series united. The classification systems analysed in this study have poor reproducibility and seem to be of little value in predicting outcome of intramedullary nailing. The KMG system may be of some use in alerting the surgeon to potential problems

Surgeons are becoming increasingly aware of the importance of matching a patient’s native offset during hip arthroplasty. During the course of a previous study investigating proximal femoral geometry in New Zea-landers it was noted that accurately measuring the femoral offset of a hip arthroplasty patient by traditional methods is difficult and inaccurate. The relationship of various surface parameters were studied to find a simple and reliable method for the surgeon. Eighteen cadaver femora were skeletalised and the offset was measured using a standardised radiological technique. The femoral neck was then sectioned from a point 1–2 cm above the lesser trochanter to the base of the trochanteric fossa. The femoral head was sectioned in the coronal plane and the centre of the head located with concentric circles. The distance from the centre of the head to the most lateral spike of bone was measured. This measure was compared to the radiological offset. Offset correlated closely with the measurement from the centre of rotation to the most lateral spike of bone provided the neck cut extends to the base of the tro-chanteric fossa. Eleven of eighteen measurements were within 2mm of true offset and fifteen were within 3mm. A simple intra-operative technique taking no longer than one or two minutes and requiring no special equipment has been devised to allow the surgeon to accurately estimate the patients femoral offset

Leg length inequality, both actual and functional, is the most important cause of disappointment for the surgeon and his patient. The reported incidence of leg length inequality of 1 cm has been reported to be between 23% and 50%, and half of these patients require a lift in their shoe. In the author’s opinion, there is a relationship between leg length and stability of the hip. Increase in leg length and offset improves soft tissue tension and reduces the dislocation rate. The goal at surgery is:. To restore the center of rotation for the hip. To restore offset, i.e. abductor moment arm. To restore hip center to lesser trochanter difference. The various tests for hip stability, soft tissue tension and contractures:. Assess component position. Assess for anterior impingement. Assess for tight anterior capsule. Assess for tight iliotibial band (Ober’s test). Assess for tight rectus, iliopsoas and adductors. Correct soft tissue balance. Leg length inequality is caused by:. Increase in anatomic leg length or offset or both. Tight anterolateral structures, which include:. IT band. Anterior and lateral capsule and gluteus maximus. Adduction contractures of the opposite hip. Spinal deformity causing pelvic tilt. Excessive trochanteric advancement causing abduction contracture