Introduction. Accurate alignment and sizing of the femoral component in total knee arthroplasty (TKA) is important for stability and functional outcomes. In relation to the shape of the distal femur, it has been reported that the medial-lateral (ML) femur width in women is narrower than that in men for the same antero-posterior (AP) length. In addition, it has been noted that the elevation of the anterior condyle in women is lower than that in men. Therefore, in TKA for women, it is suggested that a medial or lateral overhanging femoral component can cause pain or limit the range of motion (ROM). As a result, a gender-specific implant for women has been developed. However, there are few studies addressing the morphological dimensions of the distal shape of the femur in the Japanese population. The objective of this study was to reveal the appropriateness of using gender-specific implant for Japanese women. Methods. This study was based on 40 women (40 knees) and 40 men (40 knees) who had primary preoperative osteoarthritis of the knee. The average height was 161.2 cm for men and 149.4 cm for women. The average weight was 68.0 kg for men and 58.5 kg for women. These are significantly different. Resection of the distal femur for TKA was simulated with preoperative computed tomography (CT) data. The ML width on the anterior and distal cut surface, the ML width at the surgical epicondylar axis (SEA) level, the maximum AP length at the medial and lateral condyle, and the AP length after resection were measured. These values were compared between men and women, and compatibility with NexGen LPS-Flex and Gender Solution Femur (GSF) (Zimmer, Warsow, Ind) was evaluated. Results. On the anterior cut surface, the average ML width was 54.0 mm for men and 47.0 mm for women. There was a significant difference between them (P<0.01). The aspect ratio (AP/ML) at the SEA level and the resected distal surface was 0.74 and 0.65 for men and 0.76 and 0.70 for women, respectively. There were significant differences between them (P<0.01). Discussion and Conclusion. In general, the aspect ratio of the distal femur in the Japanese population was smaller than that in the Caucasian population. However, the femoral distal shape in women was narrower than that in men for the same AP length in the Japanese population. As the AP size increased, the femoral component in women tended to overhang the ML width. Therefore, the use of a gender-specific implant for women was suggested. In contrast, there were some cases in which the femoral component tended to be undersized compared with the ML width in men. [Fig. 1] For Japanese women, the use of a gender-specific component should be considered. Additionally, there is a need for further investigation of gender-specific components in men

As for the number of patients who requires total knee arthroplasty (TKA), Asian-Pacific countries will be the most important market. However, due to the paucity of anthropometric data on the proximal tibia in this population, many prostheses designed for Caucasian knees have been introduced without specific modification.The aim of the current study was to analyze the geometry of the proximal tibia to design the optimum component for the Japanese population. Anthropometric data on the proximal tibia of 100 knees in 80 patients undergoing TKA was obtained. Briefly, anterior-posterior (AP) and medial-lateral (ML) lengths were measured with a combination of two different methods, namely on the computed tomography (CT) images obtained preoperatively and intraoperative direct measurement on tibial resection surface. Reproducible measurement was possible only when the intraoperative measurement was combined with the corresponding CT images while the direction of measurements being aligned to the epicondylar axis of the femur. It was shown that smaller components with an ML of around 60 mm were rarely required. Tibial component size variation should focus on an ML length of 65 to 75 mm because 76 of 100 knees (76 %) fell into this size range. When the subjects were confined to women, 70 of 77 knees (91%) were included in this size range. The intraoperative AP to ML ratio had a negative correlation with the ML length (r = −0.412, P < 0.0001) indicating that bigger knees were shallower in the AP direction. The size variation of currently popular pros-theses were not in accordance with the geometry of the tibial resection surface shown in this study. The results of this study applied to a cross-section of the Japanese population can be used by manufacturers to create a prosthesis suitable for most of the Asian-Pacific population

Background

Massive rotator cuff tears and consequent cuff-deficient arthritis (CTA) of the shoulder can cause severe shoulder dysfunction in the elderly. Reverse total shoulder arthroplasty (RTSA) has been widely used for treatment of CTA in all over the world since its introduction in the 90's. In Japan, however, we have just started to clinically use RTSA from April 2014. In addition, we have only one choice of the implants (Aequalis Reverse, Tornier) currently, and only one size of the base-plate of the glenoid component (29 mm in diameter) is available so far. Japanese, especially elderly people, have generally smaller figure than Caucasians. We are not sure whether the base-plate would fit for the smaller Japanese. The purpose of this study was to measure the size of the glenoids in Japanese using CT images and to examine that they would fit the 29 mm base-plate.

Prophylaxis against venous thromboembolism after elective total hip replacement is routinely recommended. Our preference has been to use mechanical prophylaxis without anticoagulant drugs. A randomised controlled trial was performed to evaluate whether the incidence of post-operative venous thromboembolism was reduced by using pharmacological anticoagulation with either fondaparinux or enoxaparin in addition to our prophylactic mechanical regimen. A total of 255 Japanese patients who underwent primary unilateral cementless total hip replacement were randomly assigned to one of three postoperative regimens, namely injection of placebo (saline), fondaparinux or enoxaparin. There were 85 patients in each group. All also received the same mechanical prophylaxis during and after the operation, regardless of their assigned group. The primary measurement of efficacy was the presence of a venous thromboembolic event by day 11, defined as deep-vein thrombosis detected by ultrasonography, documented symptomatic deep-vein thrombosis or documented symptomatic pulmonary embolism. The duration of follow-up was 12 weeks.

The rate of venous thromboembolism was 7.2% with the placebo, 7.1% with fondaparinux and 6.0% with enoxaparin (p = 0.95 for the comparison of all three groups). Our study confirmed the effectiveness and safety of mechanical thromboprophylaxis without the use of anticoagulant drugs after total hip replacement in Japanese patients.

In Japan, osteoarthritis (OA) of the hip secondary to acetabular dysplasia is very common, and there are few data concerning the pathogeneses and incidence of femoroacetabular impingement (FAI). We have attempted to clarify the radiological prevalence of painful FAI in a cohort of Japanese patients and to investigate the radiological findings. We identified 176 symptomatic patients (202 hips) with Tönnis grade 0 or 1 osteoarthritis, whom we prospectively studied between August 2011 and July 2012. There were 61 men (65 hips) and 115 women (137 hips) with a mean age of 51.8 years (11 to 83). Radiological analyses included the α-angle, centre–edge angle, cross-over sign, pistol grip deformity and femoral head neck ratio. Of the 202 hips, 79 (39.1%) had acetabular dysplasia, while 80 hips (39.6%) had no known aetiology. We found evidence of FAI in 60 hips (29.7%). Radiological FAI findings associated with cam deformity were the most common. There was a significant relationship between the pistol grip deformity and both the α-angle (p < 0.001) and femoral head–neck ratio (p = 0.024). Radiological evidence of symptomatic FAI was not uncommon in these Japanese patients.

Cite this article: Bone Joint J 2013;96-B:172–6.

Aims. Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population. Methods. This is a retrospective radiological study conducted in Japan. Radiological assessment was done in accordance with predetermined radiological review protocol. A total of 241 hips were included in the study and 118 hips (49.0%) revealed radiological change from immediately after surgery to one year postoperatively; these 118 hips were eligible for further analyses. Each investigator screened whether either radiolucent lines (RLLs), cortical hypertrophy (CH), or atrophy (AT) appeared or not on the one-year radiograph. Further, three-year radiographs of eligible cases were reviewed to determine changes such as, disappeared (D), improved (I), stable (S), and progression (P). Additionally, bone condensation (BC) was assessed on the three-year radiograph. Results. CH was observed in 49 hips (21.1%), AT was observed in 63 hips (27.2%), and RLLs were observed in 34 hips (14.7%) at one year postoperatively. Among 34 hips with RLLs, 70.6% showed change of either D or I on the three-year radiograph. BC was observed in younger patients more frequently. Conclusion. The Fitmore stem works well in a Japanese population with favourable radiological change on hips with RLLs. Longer-term follow-up is required to determine clinical relevance. Cite this article: Bone Jt Open 2022;3(1):20–28

The October 2015 Hip & Pelvis Roundup. 360 . looks at: Smoking and complications in arthroplasty; Smoking cessation beneficial in arthroplasty; Intermediate care and arthroplasty; Do we still need cell salvage?; Femoroacetabular impingement in the Japanese population; Trunnionosis or taperosis and geometry; Decontamination for staphylococcus aureus works!; Policeman or opportunity? Quality improvement with registries; Death rates higher in readmission to other hospitals

Using radiography and computer tomography (CT) we studied the morphology of 83 hips in 69 Caucasian adults with osteoarthritis secondary to developmental dysplasia of the hip (DDH). A previously published series of 310 hips with primary osteoarthritis was used as a control group. According to the Crowe classification, 33 of the dysplastic hips were graded as class I, 27 as class II and 23 as class III or class IV. The intramedullary femoral canal had reduced mediolateral and anteroposterior dimensions in all groups compared with the control group. Only in Crowe class II hips was the femoral neck-shaft angle increased. The proximal femur had more anteversion in all the developmental dysplasia of the hip groups, ranging from 2° to 80°. Templated measurement of acetabular dimensions for plain radiography closely matched measurements taken by CT. The results of our study confirm the observations previously confined to the Japanese population

Introduction. The objective of this study was to verify the long-term outcome of transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH) in young patients with systemic lupus erythematosus (SLE). Methods. Consecutive series of 21 symptomatic ONFH patients with SLE (33 hips), aged 20 to 40 years, underwent ARO between 1980 and 1988. We reviewed the cases of 16 patients (25 hips), which represents a 76% rate of follow-up. Patients included 4 men and 12 women who had a mean age of 29 years at the time of surgery. A Kaplan-Meier curve was used for the survivorship analysis of ARO. Patients with surviving hips were evaluated by the modified Oxford hip score and the Medical Outcomes Study Short Form 36 (SF-36). Results. Twelve hips in 8 patients survived at the final follow-up. The average length of surviving was 25 years (range, 20 to 27 years). Three patients (6 hips) had died of unrelated causes without any conversion at the mean time of 9 years after ARO. Based on Kaplan-Meier analysis with the end point defined as any conversion, the survival rate at 25 years was 73.7% (95% confidence interval, 53.9 to 93.5%). Based on the classification of the modified Oxford hip score, 5 hips were classified as excellent, 2 hips were good, and the remaining 5 hips were fair. The average SF-36 physical component summary score was 34 points and the average mental component summary score was 46 points. The physical component summary scores of 3 patients (53.0, 56.6, 57.1) exceeded the level of the Japanese population norm. Conclusion. In ONFH patients with SLE, ARO achieved a 73.7% survival rate at 25 years

The April 2024 Hip & Pelvis Roundup³⁶⁰ looks at: Impaction bone grafting for femoral revision hip arthroplasty with the Exeter stem; Effect of preoperative corticosteroids on postoperative glucose control in total joint replacement; Tranexamic acid in patients with a history of venous thromboembolism; Bisphosphonate use may be associated with an increased risk of periprosthetic hip fracture; A balanced approach: exploring the impact of surgical techniques on hip arthroplasty outcomes; A leap forward in hip arthroplasty: dual-mobility bearings reduce groin pain; A new perspective on complications: the link between blood glucose and joint infection risks.

Aims

The Coronal Plane Alignment of the Knee (CPAK) classification has been developed to predict individual variations in inherent knee alignment. The impact of preoperative and postoperative CPAK classification phenotype on the postoperative clinical outcomes of total knee arthroplasty (TKA) remains elusive. This study aimed to examine the effect of postoperative CPAK classification phenotypes (I to IX), and their pre- to postoperative changes on patient-reported outcome measures (PROMs).

Introduction: The goal of this study was to determine the difference between weight-bearing and non weight-bearing range of motion (ROM) for Japanese subjects having either a fixed or mobile bearing TKA with either a resurfaced (RP) or unresurfaced (UP) patella. Methods: Forty subjects were evaluated using video fluoroscopy. Twenty subjects had a fixed bearing posterior cruciate retaining (PCR) TKA (10 RP, 10 UP) and twenty subjects had a mobile bearing (MB) TKA (10 RP, 10 UP). Under weight-bearing conditions, each subject performed successive deep knee bends to maximum flexion. Then, under passive, non weight-bearing conditions the subjects stood on one leg and passively flexed their knee to maximum flexion. Each trial was recorded and analyzed digitally. The angle between the femoral and tibial longitudinal axes was subtracted from 180o to obtain the amount of flexion.A single surgeon control was used. The average age of the subjects was 66.4, 78.1, 70.3, and 71.1 for subjects having PCR RP, PCR UP, MB RP, and MB UP, respectively. All total knee subjects were judged excellent clinically with HSS scores > 90 points. None complained of pain during testing. Results: The preoperative ROM for the implanted knee groups was 115, 122, 110, and 120 degrees for subjects having a PCR RP, PCR UP, MB RP, and MB UP, respectively. The average passive ROM was 106 (90–131) and 108 (72–128) degrees for subjects having a PCR RP and PCR UP, respectively. Subjects having a MB TKA experienced greater passive ROM, 120 degrees for both the MB RP (105–136o) and MB UP (105–167o). Under weight-bearing conditions, ROM decreased for all groups, with the average ROM of 101 (90–125), 108 (86–128), 109 (92–134), and 114 (94–142) degrees for subjects having a PCR RP, PCR UP, MB RP, and MB UP, respectively. The greatest amount of ROM occurred for a subject having a MB UP, 167o during passive ROM and 142o during a weight-bearing ROM. Discussion: Subjects in this study having a MB TKA experienced greater ROM for all of the compared four parameters. Subjects having a MB RP experienced greater passive (120 vs. 106) and weight-bearing (109 vs. 101) ROM compared to the PCR RP group. Similarly, subjects having a MB UP experienced greater passive (120 vs. 108) and weight-bearing (114 vs. 108) ROM compared to the PCR UP group. Interestingly, subjects having an UP TKA experienced greater ROM compared to subjects having a RP TKA. The results from this study may suggest that a mobile bearing TKA may lead to greater ROM for the Japanese populations, where achieving deep flexion is essential for normal daily activities

Aims

This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH).

Introduction. Herniation pits had been considered as a normal variant, a cystic lesion formed by synovial invagination. On the contrary, it was also suggested that herniation pits were one of the diagnostic findings in femoroacetabular impingement (FAI) because of the high prevalence of herniation pits in the FAI patients. To date, the exact etiology is still unknown. The purpose of this study was to evaluate whether there is an association between the presence of herniation pits and morphological indicators of FAI based on computed tomography (CT) examination. Materials and methods. We reviewed the CT scans of 245 consecutive subjects (490 hips, age: 21–89 years) who had undergone abdominal and pelvic CT for reasons unrelated to hip symptom from September, 2010 to June, 2011. These subjects were mainly examined for abdominal disorders. We confirmed by the questionnaire survey that there were no subjects who had symptoms of hip joints. We reviewed them for the presence of herniation pits and the morphological abnormalities of the femoral head and acetabulum. Herniation pits were diagnosed when they were located at the anterosuperior femoral head-neck junction with a diameter of more than 3 mm. We measured following four signs as indicators for FAI: α angle, center edge angle (CE angle), acetabular index (AI), and acetabular version. Mann-Whitney U-test was used for statistical analysis. Results. Herniation pits were identified in 61 of the 245 subjects or, with respect to individual hips, in 85 (17%) of 490 hips. The prevalence of herniation pits in younger subjects (<60 years, 240 hips) and elderly subjects (≥60 years, 250 hips) were 16.3% and 18.4%, respectively. Among 85 hips, the mean diameter of herniation pits was 5.9 ± 2.4 mm and it was significantly larger (p<0.01) in the elderly subjects (7.1 ± 2.4 mm) than in the younger subjects (4.7 ± 1.7 mm). In terms of the α angle, there were significant differences between the group with (49.8 ± 16.6°) and without herniation pits (40.7 ± 6.7°) in the elderly subjects, whereas not significantly different among the younger subjects. Measurements of the acetabular coverage (CE angle, AI) and the acetabular version showed no significant difference between the subject with and without herniation pits. Discussion. In the present study, the prevalence of herniation pits was 17% in asymptomatic Japanese general population. The fact that the size of the herniation pits enlarge with age may suggest these cystic lesions have degenerative characteristics with no association with FAI. Although large α angles have been recognized as a predictor of cam impingement especially in young population, it was impossible to show the relationship between α angle and presence of herniation pits in young population. These results suggest that the presence of the herniation pits has little relevance to FAI diagnosis

Aims

Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia.

Objectives

We have previously investigated an association between the genome copy number variation (CNV) and acetabular dysplasia (AD). Hip osteoarthritis is associated with a genetic polymorphism in the aspartic acid repeat in the N-terminal region of the asporin (ASPN) gene; therefore, the present study aimed to investigate whether the CNV of ASPN is involved in the pathogenesis of AD.

Aims

The aim of the study was to compare measures of the quality of life (QOL) after resection of a chordoma of the mobile spine with the national averages in the United States and to assess which factors influenced the QOL, symptoms of anxiety and depression, and coping with pain post-operatively in these patients.