Lateral femoral cutaneous nerve (LFCN) injury is a complication after periacetabular osteo-tomy (PAO) using an anterior approach, which might adversely affect the outcome. However, no prospective study has assessed the incidence and severity of this injury and its effect on the clinical outcomes over a period of time for longer than one year after PAO. The aim of this study was to assess the incidence and severity of the symptoms of LFCN injury for ≥ three years after PAO and report its effect on clinical outcomes. A total of 40 hips in 40 consecutive patients who underwent PAO between May 2016 and July 2018 were included in the study, as further follow-up of the same patients from a previous study. We prospectively evaluated the incidence, severity, and area of symptoms following LFCN injury. We also recorded the clinical scores at one year and ≥ three years postoperatively using the 36-Item Short Form Health Survey (SF-36) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores.Aims
Methods
Injury of the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) using anterior approach. We previously reported that the incidence of LFCN injury was 48% at 1 year after PAO. However, there was no study examining the sequential changes of LFCN injury status. In this study, we performed a prospective over 3-year follow-up study as to the incidence of LFCN injury as well as its clinical outcomes. This study included 40 consecutive hips in 40 patients (3 males and 37 females) who underwent PAO from May 2016 to July 2018. The mean age at surgery was 36.7 years (17 to 60). The mean observation period was 47.3 months (36 to 69). The incidence and severity of LFCN injury was evaluated, while clinical scores, including the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), were also investigated. At 3 years after PAO, LFCN injury was observed in 13 of 40 (33%) patients, in which 7 patients who had a symptom at 1 year have completely recovered. There was no significant difference in the HHS and SF-36 between patients with and without LFCN injury at 3 years. Regarding the JHEQ, a significant difference was recognized in the patient satisfaction and mental score between patients with and without LFCN injury, but there were no significant differences in the other clinical scores. The incidence of LFCN injury gradually decreased to 33% at 3 years after CPO. LFCN injury did not influence the clinician-reported outcome, while it had a negative impact on patient satisfaction and mental score based on the patient-reported outcome.
Injury to the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) performed using the anterior approach, reported to occur in between 1.5% and 65% of cases. In this study, we performed a prospective study on the incidence of LFCN injury as well as its clinical outcomes based on the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ). The study included 42 consecutive hips in 42 patients (three male and 39 female) who underwent PAO from May 2016 to July 2018. We prospectively evaluated the incidence of LFCN injury at ten days, three months, six months, and one year postoperatively. We also evaluated the clinical scores, including the HHS, SF-36, and JHEQ scores, at one year postoperatively.Aims
Methods
Indocyanine green (ICG) fluorescence angiography is an emerging technique that can provide detailed anatomical information during surgery. The purpose of this study is to determine whether ICG fluorescence angiography can be used to evaluate the blood flow of the rotator cuff tendon in the clinical setting. Twenty-six patients were evaluated from October 2016 to December 2017. The participants were categorized into three groups based on their diagnoses: the rotator cuff tear group; normal rotator cuff group; and adhesive capsulitis group. After establishing a posterior standard viewing portal, intravenous administration of ICG at 0.2 mg/kg body weight was performed, and fluorescence images were recorded. The time from injection of the drug to the beginning of enhancement of the observed area was measured. The hypovascular area in the rotator cuff was evaluated, and the ratio of the hypovascular area to the anterolateral area of the rotator cuff tendon was calculated (hypovascular area ratio).Objectives
Methods
Similar to the radiological findings in rapidly destructive arthrosis of the hip joint (RDA), subchondral insufficiency fracture of the femoral head (SIF) can result in progressive femoral head collapse of unknown etiology. We thus examined the osteoclast activity in hip joint fluid in SIF with progressive collapse in comparison to that in RDA. Twenty-nine hip joint fluid samples were obtained intraoperatively with whole femoral heads from 12 SIF patients and 17 RDA patients. SIF cases were classified into subgroups based on the presence of ≥2mm collapse on preoperative radiographs: SIF with progressive collapse (n=5) and SIF without progressive collapse (n=7). The levels of tartrate-resistant acid phosphatase (TRACP)-5b, interleukin-8, vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 were measured. Numbers of multinuclear giant cells at the subchondral region were assessed histopathologically using mid-coronal slices of each femoral head specimen. Median levels of all markers and median numbers of multinuclear giant cells in SIF with progressive collapse were significantly higher than those in SIF without progressive collapse, while there were no significant differences in SIF with progressive collapse versus RDA. Regression analysis showed that the number of multinuclear giant cells correlated positively with the level of TRACP-5b in joint fluid. This study suggests an association of increased osteoclast activity with the existing condition of progressive collapse in SIF, which was quite similar to the findings in RDA. Therefore, high activation of osteoclast cell may reflect the condition of progressive collapse in SIF as well as RDA.
Osteonecrosis of the femoral head (ONFH) is an ischemic disorder that causes bone and bone marrow necrosis. In spite of many studies, the primary cause of ischemia is still unknown. The purpose of this study is to identify the susceptibility genes in ONFH. We performed a genome-wide association study (GWAS) in 1,602 ONFH cases and 60,000 controls. Stratified GWASs based on the 3 subgroups of ONFH (corticosteroids, alcohol, idiopathic) were also performed. We then evaluated the candidate gene Two loci in 12q24.11–12 and 20q12 showed significant association with ONFH. A stratified analysis suggested that the 12q24 locus was associated with ONFH through the drinking capacity. In the 20q12 locus, A novel ONFH locus was identified at chromosome 20q12, and
This study was conducted to investigate the influence of surgical experience on the outcomes and component positioning of total knee arthroplasty (TKA). We compared the outcomes and component positioning of simultaneous bilateral TKAs performed by supervisors and trainee surgeons. A total of 20 patients (40 knees) who underwent simultaneous bilateral primary TKA using the same cruciate-retaining TKA system between 2011 and 2015 were included. The mean patient age was 76 years (range: 64 to 86 years). There were 2 males and 18 females. The first phase of the operation was performed on the knee that was more severely degenerated by one supervisor who had performed over 1000 TKAs. The other knee was operated on next by trainee surgeons who had performed less than 20 TKAs. The knees were categorized into two groups: those operated on by supervisors (group S) and those operated on by trainee surgeons (group T). Outcome measures included range of motion (ROM), Knee Score (KS), and Function Score (FS). We also evaluated operative time, alignment of the leg, and the orientation of components, which was determined on post-operative long-leg coronal films.Aims
Patients and Methods
Dislocation is one of the most important complications in THA. Dual mobility cup (DMC) inserts reduce the risk for dislocation after total hip arthroplasty by increasing the oscillation angle. A lower rate of dislocation with use of a DMC insert has been reported in different studies. But there is no available research that clearly delineates the stability advantages of DMC inserts in primary THA. The aim of our study was to evaluate the area of the safe zone for a DMC insert, compared to a fixed insert for different anteversion angles of the femoral component. A model of the pelvis and femur were developed from computed tomography images. We defined the coordinate system of the pelvis relative to the anterior pelvic plane and the coordinate system of the femur relative to the posterior condylar plane. In our model, we simulated a positive anteversion position of the acetabular cup. The lower border for cup inclination is 50°. The safe zone was evaluated for the following range of motion of the implant: 120° of flexion, 90° of flexion 30° of internal rotation, 30° of extension, 40° of abduction, 40° of adduction, and 30° of external rotation. (Fig.1) The safe zone was calculated for both a fixed insert and a DMC insert over a pre-determined range of three-dimensional motion, and the effect of increasing the anteversion position of the femoral component from 5° to 35° quantified. The ratio of the safe zone for a DMC insert to a fixed insert was calculated.INTRODUCTION
Material and Methods
Compared with the cruciate-retaining (CR) insert for total knee arthroplasty (TKA), the cruciate-substituting (CS) insert has a raised anterior lip, providing greater anterior constraint, and thus, can be used in cases of posterior cruciate ligament (PCL) sacrifice. However, studies have shown that the PCL maintains femoral rollback during flexion, acts as a stabilizer against distal traction force and aids knee joint proprioception; therefore, the argument for PCL excision in CS TKA remains controversial. The purpose of this study was to analyze CS TKA kinematics and identify the role of the PCL. Seven fresh-frozen lower-extremity cadaver specimens were analyzed using Orthomap® Precision Knee Navigation software (Stryker Orthopaedics, Mahwah, NJ, USA). They were surgically implanted with Triathlon® components (Stryker Orthopaedics). The CS insert has a raised anterior lip, and the posterior geometry shares the same profile as the CR, so we can choose retaining or sacrificing the PCL. Six patterns were analyzed: (1) natural knee; (2) only anterior cruciate ligament excision; (3) CS TKA, PCL retention, and bony island preservation; (4) CS TKA, PCL retention, and bony island resection; (5) CS TKA and PCL excision; and (6) CR TKA and PCL excision. Center of the knee and center of the proximal tibia were registered using navigation system, and the magnitudes of the condylar translation were evaluated. And then, using trigonometric function, the magnitude of anterior-posterior translation of the femur was calculated.Introduction
Methods
Pelvic posterior tilt change (PPTC) after THA is caused by release of joint contracture and degenerative lumbar kyphosis. PPTC increases cup anteversion and inclination and results in a risk of prosthesis impingement (PI) and edge loading (EL). There was reportedly no component orientation of fixed bearing which can avoid PI and EL against 20°PPTC. However, dual mobility bearing (DM) has been reported to have a large oscillation angle and potential to withstand EL without increasing polyethylene (PE) wear against high cup inclination such as 60∼65°. The purpose of this study was to investigate the optimal orientation of DM-THA for avoiding PI and EL against postoperative 20°PPTC.Introduction
Objective
Computer navigation systems are quite sophisticated intra-operative support systems for the precise placement of acetabular or femoral components in THA. However, few studies have addressed the clinical benefits derived from using a navigation system to achieve precise placement of the implants. The purpose of this study is to investigate the early dislocation rate of navigation-assisted primary THA through a posterior approach in order to clarify the short-term benefit of using a computer navigation system. We retrospectively reviewed the early dislocation rate (within 12 months after surgery) of 475 consecutive primary cementless or hybrid THAs with femoral head sizes ≦32mm performed via posterior approach. There were 85 men and 390 women, with a mean age of 60 years (17 to 88) at operation. Preoperative diagnoses included osteoarthritis in 384 hips, osteonecrosis in 45 hips, and others in 46 hips (ex. RA, trauma, infection, congenital disease). All THAs were planned using a 3D templating system based on the combined anteversion theory, performed by single surgeon through a posterior approach with repair of the posterior capsule, assisted by a CT-based surface matching type computer navigation system for cup implantation. All patients were directly followed up at least 1 year after surgery. We classified all 475 joints into four groups: normal or mildly deformed hips (Group A; 308 joints, ex. primary OA, Crowe group 1, osteonecrosis), moderately deformed hips (Group B; 97 joints, ex. Crowe group 2, protrusio acetabuli, Perthes like deformity), severely deformed hips (Group C; 53 joints, ex. Crowe group 3 or 4, ankylosis, fused hip), and neuromuscular and cognitive disorders (Group D; 17 joints), and examined the dislocation rate for each group.Introduction
Methods
The number of total hip arthroplasties has been increasing worldwide, and it is expected that revision surgeries will increase significantly in the near future. Although reconstructing normal hip biomechanics with extensive bone loss in the revision surgery remains challenging. The custom−made acetabular component produced by additive manufacturing, which can be fitted to a patient's anatomy and bone defect, is expected to be a predominant reconstruction material. However, there have been few reports on the setting precision and molding precision of this type of material. The purpose of this study was to validate the custom−made acetabular component regarding postoperative three−dimensional positioning and alignment. Severe bone defects (Paprosky type 3A and 3B) were made in both four fresh cadaveric hip joints using an acetabular reamer mimicking clinical cases of acetabular component loosening or osteolysis in total hip arthroplasty. On the basis of computed tomography (CT) after making the bone defect, two types of custom−made acetabular components (augmented type and tri−flanged type) that adapted to the bone defect substantially were produced by an additive manufacturing machine. A confirmative CT scan was taken after implantation of the component, and then the data were installed in an analysis workstation to compare the postoperative component position and angle to those in the preoperative planning.Introduction
Methods
Many authors have described component position and leg length discrepancy (LLD) after total hip arthroplasty (THA) as the most important factors for good postoperative outcomes. However, regarding the relationships between component position and different approaches for THA, the optimal approach for component position and LLD remains unknown. The aims of this study were to compare these factors among the direct anterior, posterolateral, and direct lateral approaches on postoperative radiographs retrospectively, and determine which approach leads to good orientation in THA. We retrospectively evaluated 150 patients who underwent unilateral primary THA in our department between January 2009 and December 2014, with the direct anterior, posterolateral, or direct lateral approach used in 50 patients each. Patients with significant hip dysplasia (Crowe 3 or 4), advanced erosive arthritis, prevented osteotomy of the contralateral hip, and body mass index (BMI) of more than 30 were excluded. The mean age, sex, and preoperative diagnosis of the affected hip were equally distributed in patients who underwent THA with the different approaches. The mean BMI did not differ significantly among the groups. The radiographic measurements included cup inclination angle, dispersion of cup inclination from 40°, and LLD on an anteroposterior pelvic radiograph, and cup anteversion angle and dispersion of cup anteversion from 20° on a cross-table lateral radiograph postoperatively. We also measured the ratios of patients with both cup inclination of 30–50° and cup anteversion of 10–30° (target zone in our department), femoral stem varus/valgus, and LLD of 10 mm or less. Statistical analyses used an unpaired Introduction
Methods
We perform PAO via a modified Smith-Petersen approach. The purpose of this study was to investigate the result of PAO via a modified Smith-Petersen approach at a minimum 10-years' follow-up. We retrospectively reviewed 209 hips in 179 patients with acetabular dysplasia who underwent PAO with a modified Smith-Petersen approach from August 1995 to April 2010. Exclusion criteria were as follows: under 10 year follow-up, incomplete clinical or radiographic data. Harris hip score (HHS) was investigated preoperatively, at the time of most improvement and at the final follow-up for clinical evaluation. Tönnis classification was investigated preoperatively and at the final follow-up for evaluation of osteoarthritis. Center edge (CE) angle and acetabular roof obliquity (ARO) were investigated preoperatively, postoperatively and at the final-follow up for radiographic evaluation. Tönnis classification and radiographic parameters were investigated on anterior-posterior radiographs. Patients of conversion of PAO to total hip arthroplasty (THA) were investigated for preparing Kaplan Myer survival analysis. The Wilcoxon signed-rank test was used to compare changes in HHS and radiographic parameters between the preoperative and the postoperative values. Statistical significance was defined a priori as p < 0.05.Introduction
Methods
According to proposal of Noble, the femoral bone marrow cavity form of patients who underwent Total Hip Arthroplasty (THA) can be classified under 3 categories; those are Stovepipe, Normal and Champagne-fluted. We developed typical sodium chloride femoral model was created by 3D prototyping technique. The purpose was to identify the relationship of pressure zone of the surrounding areas between femoral bone marrow cavity form and hip stem. As opponent clarified stem design concept Zweymüller type model was used. According to CT data with the patients who underwent THA, the sodium chloride femoral model was custom-made and selected as the representative model based on Noble's 3 categories. Eight models of each category were used to performed mechanical test.Introduction
Materials and Method
On the basis of a proposal by Noble, the marrow cavity form can be classified into three categories: stovepipe, normal, and champagne-fluted. In the present study, three typical finite element femoral models were created using CT data based on Noble's three categories. The purpose was to identify the relationship of stress distribution of the surrounding areas between femoral bone marrow cavity form and hip stem. The results shed light on whether the distribution of the high-stress area reflects the stem design concept. In order to improve the results of THA, researchers need to consider the instability of a stem design based on the pressure zone and give feedback on future stem selection. To develop finite element models, two parts (cortical bone and stem) were constructed using four-node tetrahedral elements. The model consisted of about 40,000 elements. The material characteristics were defined by the combination of mass density, elastic coefficient, and Poisson's ratio. Concerning the analysis system, HP Z800 Workstation(HP, Japan) was used as hardware and LS-DYNA Ver. 971 (Livermore Software Technology Corporation, USA) as software. The distal end of the femur was constrained in all directions. On the basis of ISO 7206 Part 4,8 that specifies a method of endurance testing for joint prostheses, the stem was tilted 10°, and a 500 N resultant force in the area around the hip joint was applied to the head at an angle of 25° with the long axis. Automatic contact with a consideration of slip was used. Von Mises stress during a 1.0 s period after loading was analyzed, and stress distribution in the stem and its maximum value were calculated.Introduction
Methods
In performing posterior cruciate ligament- retaining total knee arthroplasty (CR-TKA), the original surgical instrument was devised to obtain the range of motion and stability of the knee joint adequate for daily life of Japanese people. We have presumed the tentative joint line as intercondylar notch point of the distal femur, and performed surgery using
There is a large gap between UKA and TKA in terms of tissue preservation including bone stock and knee ligament. We have recently introduced bicompartmental UKA (Bi-UKA) to fill the gap and achieve more “physiological” knee than TKA. In this study, we report the short-term results of Bi-UKA. Thirty knees in twenty-nine osteoarthritis patients who underwent Bi-UKA from December 2010 to December 2013 (6 males and 23 females, average age of 75) were clinically and radiologically evaluated with an average observation period of 19 months. The operative indications were (1)confirmed diagnosis of medial and lateral osteoarthritis or osteonecrosis with preserved status of patellofemoral joint; (2)range of knee flexion greater than 110°; (3)flexion contracture less than 20°; (4)clinically stable knee in the frontal and sagittal plane; (5)correctable knee deformity with fine knee congruency. In all cases, fixed type UKA was implanted through a tibia dependent cut using a spacer block. Zimmer Uni and TRIBRID UKA (Kyocera Medical Corporation) were implanted in 18 and 12 cases, respectively.Purpose
Subjects and Methods
The incidence of osteonecrosis was significantly lower in the anti-vasospasm agent group (32%) than that in the control group (75%). Vasospasm is one of the important factors involved in the pathogenesis of steroid-induced osteonecrosis. A number of studies have suggested that ischemia is the principal pathomechanism of osteonecrosis, however, the detailed mechanism responsible for ischemia remains unclear. It has recently been reported that the Rho/Rho-kinase mediated pathway (Rho-kinase pathway) is considered to be involved in the possible pathogenesis of various cardiovascular disorders as well as cerebral vasospasm. We examined the effects of fasudil (Rho-kinase inhibitor), an anti-vasospasm agent, on the development of steroid-induced osteonecrosis in rabbits.Summary Statement
Introduction
Fracture during total hip arthroplasty occurs partly because the acquisition of fixation at the time of stem implantation depends on the operator's experience and sensation due to the absence of definite criteria. Therefore, an objective evaluation method to determine whether the stem has been appropriately implanted is necessary. We clarified the relationship between the hammering sound frequency during stem implantation and internal stress in a femoral model, and evaluated the possible usefulness of hammering sound frequency analysis for preventing intraoperative fracture. Three types of cementless stem were used. Orthopedists performed stem insertion using a procedure similar to that employed in routine operation. Stress was estimated by finite element analysis using the hammering force calculated from the loading sensor as a loading condition, and frequency analysis of hammering sound data obtained using a microphone was performed (Fig. 1). Finite element analysis showed a decrease in the hammering sound frequency with an increase in the estimated maximum stress (Fig. 2, 3). When a decrease in frequency was observed, adequate hammering had already been performed to achieve press-fit stability. Therefore, there is a possibility that the continuation of hammering induces intraoperative fractures that become a problem. Based on the relationship between stress and frequency, the evaluation of changes in frequency may be useful for preventing the development of intraoperative fractures. When a decrease in frequency is observed, the hammering force should be reduced thereafter. Hammering sound frequency analysis may allow the prediction of bone fractures that can be visually confirmed, and may be a useful objective evaluation method for the prevention of intraoperative bone fracture.
The systemic use of steroids and habitual alcohol
intake are two major causative factors in the development of idiopathic
osteonecrosis of the femoral head (ONFH). To examine any interaction
between oral corticosteroid use and alcohol intake on the risk of
ONFH, we conducted a hospital-based case-control study of 71 cases
with ONFH (mean age 45 years (20 to 79)) and 227 matched controls
(mean age 47 years (18 to 79)). Alcohol intake was positively associated
with ONFH among all subjects: the adjusted odds ratio (OR) of subjects
with ≥ 3032 drink-years was 3.93 (95% confidence interval (CI) 1.18
to 13.1) compared with never-drinkers. When stratified by steroid use,
the OR of such drinkers was 11.1 (95% CI 1.30 to 95.5) among those
who had never used steroids, but 1.10 (95% CI 0.21 to 4.79) among
those who had. When we assessed any interaction based on a two-by-two
table of alcohol and steroid use, the OR of those non-drinkers who
did use steroids was markedly elevated (OR 31.5) compared with users
of neither. However, no further increase in OR was noted for the
effect of using both (OR 31.6). We detected neither a multiplicative
nor an additive interaction (p for multiplicative interaction 0.19;
synergy index 0.95), suggesting that the added effect of alcohol
may be trivial compared with the overwhelming effect of steroids
in the development of ONFH. Cite this article:
A delay in establishing the diagnosis of an occult
fracture of the hip that remains unrecognised after plain radiography
can result in more complex treatment such as an arthroplasty being
required. This might be avoided by earlier diagnosis using MRI.
The aim of this study was to investigate the best MR imaging sequence
for diagnosing such fractures. From a consecutive cohort of 771
patients admitted between 2003 and 2011 with a clinically suspected
fracture of the hip, we retrospectively reviewed the MRI scans of
the 35 patients who had no evidence of a fracture on their plain
radiographs. In eight of these patients MR scanning excluded a fracture
but the remaining 27 patients had an abnormal scan: one with a fracture
of the pubic ramus, and in the other 26 a T1-weighted
coronal MRI showed a hip fracture with 100% sensitivity. T2-weighted
imaging was undertaken in 25 patients, in whom the diagnosis could
not be established with this scanning sequence alone, giving a sensitivity
of 84.0% for T2-weighted imaging. If there is a clinical suspicion of a hip fracture with normal
radiographs, T1-weighted coronal MRI is the best sequence
of images for identifying a fracture.
Transtrochanteric curved varus osteotomy is one of the effective joint-preserving operations for osteonecrosis (ON) of the femoral head. We correlated various factors with the radiological outcome of this procedure. We reviewed 74 hips in 63 patients who had a minimum follow-up of 5 years after transtrochanteric curved varus osteotomy for the treatment of ON. There were 28 men and 35 women who had a mean age of 33 years (range, 15 to 68 years) at the time of surgery. Clinical assessment was made based on the Harris hip score (HHS). Radiographically, we investigated various factors; affected lesion, stage and type (localization of the necrotic lesion) of ON, varus degree, post-operative intact ratio, progression of collapse, and joint-space narrowing. On the basis of postoperative radiographs, the hips were divided into 2 groups (Group I: either the progression of collapse or joint-space narrowing, Group II: neither progression of collapse or joint-space narrowing). The related factors with radiological outcome were analyzed by using multivariate analysis (Stepwise discriminant analysis).Introduction
Methods
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). 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).Introduction
Methods
Subchondral insufficiency fracture of the femoral head (SIF) is a recently proposed concept. It is generally seen in elderly people, however, some young adults have also been reported to suffer from this fracture. The purpose of this study was to investigate the clinical results of a transtrochanteric anterior rotational osteotomy (ARO) performed in young adults with SIF. This study focused on young SIF cases (age range from 10 to 29 years). Five patients were diagnosed to have SIF at our institution and conservative treatment was initially performed. The symptoms resolved in 1 case while the other 4 cases showed progression of a collapse. In these 4 cases, ARO was performed, since the fractured area was located in the anterosuperior portion of the femoral head. The average age of the patients was 22 years (range, 16 to 29 years) at the time of surgery, consisting of 2 men and 2 women.Introduction
Methods
Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-intensity band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-intensity band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low intensity band on the T1-weighted magnetic resonance images were also examined, with regard to the band length, band thickness and band length ratio; which is defined as a proportion of the band length to the weight-bearing portion of the femoral head.Introduction
Methods
Subchondral insufficiency fracture (SIF) needs to be differentiated from osteonecrosis. The purpose of this study was to evaluate the imaging and histopathological findings of patients 60 years or older with radiological evidence of subchondral collapse of the femoral head. We reviewed 77 consecutive hips in 56 patients aged 60 years or older, which showed subchondral collapse on radiographs. According to the shapes of low-intensity bands on T1-weighted images of magnetic resonance imaging (MRI), the patients were divided into 2 groups. Group A showed a concavity of the articular surface: characteristic appearances of osteonecrosis, and Group B showed an irregular convexity of the articular surface: characteristic appearances of SIF.Introduction
Methods
The objective of this study was to investigate the incidence of steroid-induced osteonecrosis (ON) among male and female rabbits. Forty-seven adult rabbits (male, n = 24; female, n = 23) were injected once intramuscularly into the right gluteus medius muscle with 20 mg/kg of methylprednisolone acetate. Hematological examinations were performed just before and at 1 and 2 weeks after the corticosteroid injection. Two weeks after the injection, both femora and humeri were histopathologically examined for the presence of ON, and the bone marrow fat cells were examined morphologically.Introduction
Methods
In Japan, idiopathic osteonecrosis of the femoral head (ONFH) is designated as a specified rare and intractable disease in patients for whom medical care is subsidized through the Specified Disease Treatment Research Program. Each patient is approved for the subsidy based upon a prefectural governmental review after filing an application together with a clinical research form documenting the patient's medical history, laboratory/clinical findings, and treatment. The purpose of this study was to conduct a fact-finding study of ONFH patients in the Fukuoka Prefecture based on clinical research forms of the Specified Disease Treatment Research Program. The distribution by gender and age of ONFH patients who filed an application for subsidy under this program between 1999 and 2008 was investigated on the basis of clinical research forms in the Fukuoka Prefecture. For comparative purposes, we also investigated the distribution by gender and age of ONFH patients who had a final diagnosis of ONFH at our institution during the past three years.Background
Methods
Transposition osteotomy of the acetabulum (TOA) was the first periacetabular osteotomy for the osteoarthritis hips due to acetabular dysplasia, in which the acetabulum was transposed with articular cartilage. TOA improves coverage of the femoral head to restore congruity and stability, and also prevent further osteoarthritis deterioration and induce regeneration of the joint. Many good clinical outcomes have been reported for such periacetabular osteotomies for osteoarthritis of the hips at an early stage. In contrast, the clinical outcome is controversial for those hips at an advanced stage, in which the joint space has partly disappeared. The purpose of this study was to investigate whether TOA is an appropriate option for treatment of osteoarthritis of the hips at the advanced stage by comparing with matched control hips at the early stage. Between 1998 and 2001, TOA was performed in 104 hips of 98 patients. Sixteen of 17 hips (94%) with osteoarthritis at the advanced stage were examined and compared with 37 matched control hips at the early stage. The mean age at the operation was 48(38–56) and the mean follow-up period was 88 (65–107) months. TOA corrected the acetabular dysplasia and significantly improved containment of the femoral head. No hips had secondary operations including THA. Clinical scores were also significantly improved in both of the groups. In the advanced osteoarthritis cases, there was a tendency for abduction congruity before transposition osteotomy of the acetabulum to reflect the clinical outcome. TOA is a promising treatment option for the advanced osteoarthritis of the hips as well as for those patients at the early stage when preoperative radiographs show good congruity or containment of the joint.
In recent years, the progressive technology of hemodialysis provides long-term survival for renal failure patients. On the other hand, avascular necrosis of the femoral head from the use of steroids or renal osteodystorophy or femoral neck fracture due to amyloid arthropathy have increased. In such cases, bipolar femoral head prosthesis (FHP) and total hip replacement (THR) are usually performed. But it is at risk of developing severe complications, such as early loosening or infection of the implant. The aim of this study is to evaluate the stability of the cementless stems in radiograms and clinical results after FHP or THR using three types cementless prosthesis in hemodialysis patients. The study included 14 patients (19 hips) on hemodialysis who underwent FHP or THR using three types cementless prosthesis at our institution between 1983 to 2005 and we could follow up at least two years. There were 8 women (11 hips) and 6 men (8 hips) with an average age of 43.9 years (range, 20–88). The average follow-up was 6.75 years. The average hemodialysis term was 10.5 years. Three types of hip prosthesis (7 stems were CLS, 6 stems were IMC, 6 stems were Duetto S-I) has been used for the treatment at our institution in the past. The initial diagnosis was avascular necrosis of the femoral head in 8 hips, femoral neck fracture in 5, osteoarthritis in 4 and amyloid arthropathy in two. We assessed at least 3° of varus-valgus deviation or at least 3 mm of subsidence as aseptic loosening of stems, and assessed radiolucent line and stress shielding of the stems in radiograms, also. As for clinical results, we measured postoperative infection rate and revision rate. Aseptic loosening of stems were identified in 3 hips (15.8%). Radiolucent lines were identified in 5%–26% of hips categolised by Gruen’s classification zone I-VII, although their zones differed according to the stem model. Stress shieldings were identified in 10 hips (53%), most of which were level 1, according to the criteria described by Engh et al. Infection rate and revision rate were 5.3% (1 hip) and it was a long-term hemodialysis patient. Several studies report, there is a high probability that early loosening of the stems is associated with amyloid deposition. We experienced early loosening of the stems in our case and considered prevention of amyloid deposition very important in improving the prognosis of the arthroplasty. We must follow carefully hemodialysis patients after an operation because their nutrition level is low and their bodies are compromised due to steroids use and their postoperative infection rate is high.
In order to clarify how intra-articular lesions
influence the survival of a periacetabular osteotomy in patients
with dysplasia of the hip, we performed an observational study of
121 patients (121 hips) who underwent a transposition osteotomy
of the acetabulum combined with an arthroscopy. Their mean age was
40.2 years (13 to 64) and the mean follow-up was 9.9 years (2 to
18). Labral and cartilage degeneration tended to originate from
the anterosuperior part of the acetabulum, followed by the femoral
side. In all, eight hips (6.6%) had post-operative progression to
Kellgren–Lawrence grade 4 changes, and these hips were associated
with the following factors: moderate osteoarthritis, decreased width
of the joint space, joint incongruity, and advanced intra-articular
lesions (subchondral bone exposure in the cartilage and a full-thickness
labral tear). Multivariate analysis indicated subchondral bone exposure
on the femoral head as an independent risk factor for progression
of osteoarthritis (p = 0.003). In hips with early stage osteoarthritis,
femoral subchondral bone exposure was a risk factor for progression of
the grade of osteoarthritis. Although the outcome of transposition osteotomy of the acetabulum
was satisfactory, post-operative progression of osteoarthritis occurred
at a high rate in hips with advanced intra-articular lesions, particularly
in those where the degenerative process had reached the point of
femoral subchondral bone exposure.
Several stems have been used for revision of total hip replacement (THR). Moreover, management of proximal femoral bone loss at the time of revision THR remains one of the challenges for hip surgeons. Recently, impaction bone grafting has been suggested to resolve this problem, but it is a demanding technique that results in frequent complications. We have used the Wagner self-locking stem with cancellous chip allograft for reconstruction of proximal femoral bone defect during revision surgery since 1992. This study evaluated the midterm results of using Wagner revision stem with bone allograft for femoral revision of THR. We could evaluate forty-one femoral revisions performed between 1992 and 2005 using Wagner revision stem with bone allograft. All patients had been followed for a minimum of three years with a mean follow-up of 8.6 years. Preoperative radiological femoral bone defects were assessed and classified by Gustillo’s classification. Subsidence of the stem was measured on radiograms taken immediately after revision surgery and again at the latest follow-up. Femoral component fixation was graded as radiographic ingrowth, fibrous stable, or unstable according to the criteria described by Engh et al. The incidence of surgical complications was examined. Allografts were assessed for incorporation into host bone as evidenced by trabecular bridging of the host-graft interface. A clear reduction in density or breakdown of the allograft was defined as bone resorption. Kaplan-Meier survival analysis was performed. The end point was revision because of mechanical loosening of the stem. Bone defects were classified as: 10 hips type I, 20 hips type II, and 7 hips type III and 4 hips were a periprosthetic fracture. Subsidence was measured at the time of last follow-up in six hips (3, 3, 12, 16, 21, 30 mm). At the latest follow-up 37 of 41 stems were stable. Allograft incorporation could clearly be observed in the proximal femoral bone defects of 31 stems. Three stems were defined as showing bone resorption. Surgical complications included 11 intraoperative fractures, two femoral shafts were perforated during reaming, one dislocation postoperatively, and 3 greater trochanter pseudoarthroses. There was one deep infection, and these cases were excluded from survivorship analysis. One unstable stem and one stem with infection had to be revised. Kaplan-Meier survival was 97.1 % at 10 years. Wagner self-locking stem with allograft for reconstruction for proximal femoral bone defect in revision surgery is a beneficial procedure. However, because there is a high incidence of intraoperative fractures, surgery should be performed carefully.
In order to investigate the mechanisms of collapse in osteonecrosis of the femoral head, we examined which part of the femoral head was the key point of a collapse and whether a collapsed region was associated with the size of the necrotic lesion. Using 30 consecutive surgically removed femoral heads we retrospectively analysed whole serial cut sections, specimen photographs, specimen radiographs and histological sections. In all of the femoral heads, collapse consistently involved a fracture at the lateral boundary of the necrotic lesion. Histologically, the fractures occurred at the junction between the thickened trabeculae of the reparative zone and the necrotic bone trabeculae. When the medial boundary of the necrotic lesion was located lateral to the fovea of the femoral head, 18 of 19 femoral heads collapsed in the subchondral region. By contrast, when the medial boundary was located medial to the fovea, collapse in the subchondral region was observed in four of 11 femoral heads (p = 0.0011). We found that collapse began at the lateral boundary of the necrotic lesion and that the size of the necrotic lesion seemed to contribute to its distribution.
We investigated the factors related to the radiological outcome of a transtrochanteric curved varus osteotomy in patients with osteonecrosis of the hip. We reviewed 73 hips in 62 patients with a mean follow-up of 12.4 years (5 to 31.1). There were 28 men and 34 women, with a mean age of 33.3 years (15 to 68) at the time of surgery. The 73 hips were divided into two groups according to their radiological findings: group 1 showed progression of collapse and/or joint-space narrowing; group 2 had neither progressive collapse nor joint-space narrowing. Both of these factors and the radiological outcomes were analysed by a stepwise discriminant analysis. A total of 12 hips were categorised as group 1 and 61 as group 2. Both the post-operative intact ratio and the localisation of the necrotic lesion correlated with the radiological outcome. The cut-off point of the postoperative intact ratio to prevent the progression of collapse was 33.6%, and the cut-off point to prevent both the progression of collapse and joint-space narrowing was 41.9%. The results of this study indicate that a post-operative intact ratio of 33.0% is necessary if a satisfactory outcome is to be achieved after this varus osteotomy.
Combined anteversion (CA) is defined as the sum of the anteversions of acetabular and femoral components. In this study, we determined the appropriate CA in a variety of femoral versions using a total hip arthroplasty model. In addition, we also examined the usefulness of a changeable neck to improve range of hip motion in these cases. Using a THA model, the range of motion (ROM) was tested in various CA values obtained by changing the anteversion of a cup in six increments after setting the femoral anteversion to 20° or 60° anteversion and 20° retroversion. The angle of the changeable neck was changed in 11 increments of 5°. To evaluate stability, the range of internal rotation at 90° flexion, the external rotation at 0° extension, and the range flexion was measured when any impingement occurred prior to dislocation. We defined the required ROM that met 40° internal rotation, 30° external rotation, and 110° flexion. In normal 20° anteversion group, the required ROM was achieved with CA between 30° and 50° without using any changeable necks. In excessive anteversion 60° group, the range of external rotation was less than 10° even when the acetabular component was set 10° retroverted, because of the bone impingement between the greater trochanter and the posterior acetabulum. When 25° retroverted changeable neck was used, ROM improved to 30° external rotation and satisfied the required ROM. In 20° retroversion group, the internal rotation angle was 31° even when the acetabular component was opened 35° anteverted, because of anterior neck-liner impingement. When 25° anteverted changeable neck was used, ROM improved to 39° internal rotation and 130° flexion. In cases with normal anteversions, the required ROM can be achived by adjusting CA. In cases with excessive anteversion or retroversion, there was a limitation of the CA adjustment. The use of changeable necks allows for further improvement of ROM by compensating femoral anteversions.
Management of severe acetabular bone loss at the time of revision total hip replacements (THR) remains has been one of the greater challenges for hip surgeon. Recently, many methods of acetabular reconstruction have been described and various materials are used for supplement of the bone stock deficiency in acetabular revision THR. The purpose of this study was to evaluate the midterm results of the using support ring with bone allografts in acetabular revision THR.
From 1990 to 2005, forty-six acetabular revisions using supporting ring with bone allografts were performed at our institution. All patients were followed up for a minimum of three years with a mean follow-up of 7.5 years. Pre-operative radiological acetabular bone defects were assessed and classified by author’s classification (Itoman’s classification). Radiological analysis involved a general qualitative evaluation. The position of the acetabular reinforcement ring was measured on radiograms, taken immediately after revision surgery and again at the time of last follow-up. Using a MEM template, cranio-central migration and cup inclination angle were measured. Kaplan-Meier survivorship analysis was performed. The end point was revision because of mechanical loosening of the acetabular implant. We used thirty-six Ganz rings, six Müller rings, three Kerboull T-plate and two Burch-Schneider anti-protrusion cages. The acetabular bone defects were classified as: 10 hips Type B (central defect), 9 hips Type C (cranial defect), 27 hips Type D (cranial-central defect). Migration of acetabular component was defined as a change of >
5mm in the cranial or central direction of the cup or a change in the cup inclination angle of >
5° at the time of last follow-up. All the Eleven acetabular components which had defined as loose were Type D. One acetabular component was revised because of mechanical loosening, four were revised because of infection, and one was broken polyethylene liner. Kaplan-Meier survivorship of these reconstructions was 96.2 % at 10 years. Allograft reconstruction of acetabular bone defect in revision total hip replacement is beneficial procedure. The remaining pelvic bone is usually in poor condition, therefore, it is necessary to ensure primary fixation with the reinforcement ring with bone allografts.
Treating Crowe type 3 or 4 of hips tends to be technically difficult when performing total hip arthroplasty (THA) due to the severely dysplastic acetabulum and proximal femur in addition to a high dislocation of the hip. Since the socket is limited to being placed at the original hip center, a femoral shortening osteotomy is often required in order to prevent neurovascular problems. This osteotomy will need the stability of the femoral stem with both the proximal and the distal femoral bones. We used the modular S-ROM stem, which has a valuable proximal structure and a distal flute structure to stabilize the stem with the proximal and distal femoral fragments. The purpose of this study was to report the clinical and radiographic results of the primary THA with a shortening osteotomy while also using the S-ROM prosthesis. Between 1994 and 2004, primary THA using the S-ROM prosthesis was performed on 7 hips in 6 cases (1 male, 5 females). Crowe type 3 or 4 was observed in one and 6 hips, respectively. The mean age at operation was 56 years old (range 51~60). The mean follow-up period was 41 months (range 24~56 months). Four hips had previously undergone a subtrochanteric valgus osteotomy. All hips underwent a step-cut femoral osteotomy at the proximal metaphysis for the shortening and/or correction of angulations with on-lay chip bone grafts. All of the used stems were straight type. The clinical outcome was evaluated using the clinical scoring system of hip joints established by the Japanese Orthopaedic Association (JOA). According to a 100 point scale, pain was determined to be 40, ROM was 20, gait was 20 and ADL was 20. No hips had undergone any revision surgery as of the most recent follow-up. Union was achieved at the osteotomy site in all hips. Neither osteolysis nor a loosening of the implant was radiographically observed. The mean JOA score before THA and at the last follow-up was 41 (31–48) and 81 (62–91) points, respectively. The mean postoperative days to start full weight bearing was 53 days (range 49~70). In two cases (28%), a procedure using circular wiring was performed to treat a crack in the proximal femur. The S-ROM prosthesis was thus found to be useful for primary THA with a shortening metaphyseal femoral osteotomy for hips in patients with Crowe type 3 or 4 developmental dysplasia.
Transtrochanteric curved varus osteotomy was designed to avoid some of the disadvantages of varus wedge osteotomy, such as post-operative leg-length discrepancy. In this retrospective study we investigated the leg-length discrepancy and clinical outcome after transtrochanteric curved varus osteotomy undertaken in patients with osteonecrosis of the femoral head. Between January 1993 and March 2004, this osteotomy was performed in 42 hips of 36 patients with osteonecrosis of the femoral head. There were 15 males and 21 females with a mean age at surgery of 34 years (15 to 68). The mean follow-up was 5.9 years (2.0 to 12.5). The mean pre-operative Harris hip score was 64.0 (43 to 85) points, which improved to a mean of 88.7 (58 to 100) points at final follow-up. The mean varus angulation post-operatively was 25° (12° to 38°) and the post-operative mean leg-length discrepancy was 13 mm (4 to 25). The post-operative leg-length discrepancy showed a strong correlation with varus angulation (Pearson’s correlation coefficient; r = 0.9530, p <
0.0001), which may be useful for predicting the leg-length discrepancy which can occur even after transtrochanteric curved varus osteotomy.
We undertook 114 arthroscopic meniscal repairs in 111 patients and subsequently carried out second-look arthroscopy to confirm meniscal healing at a mean of 13 months after repair. Stable healing at the repaired site was seen in 90. Of these, however, 13 had another arthroscopy later for a further tear. The mean period between the repair and the observation of a repeat tear was 48 months. Of the 13 patients, 11 had returned to high activity levels (International Knee Documentation Committee level I or II) after the repair. An attempt should be made to preserve meniscal function by repairing tears, but even after arthroscopic confirmation of stable healing repaired menisci may tear again. The long-term rate of healing may not be as high as is currently reported. Second-look arthroscopy cannot predict late meniscal failure and may not be justified as a method of assessment for meniscal healing. Young patients engaged in arduous sporting activities should be reviewed regularly even after arthroscopic confirmation of healing.
We treated 75 patients with benign bone tumours by curettage and filling the defect with calcium hydroxyapatite (HA). There were 28 women and 47 men with a mean age of 27.7 years (3 to 80). The mean follow-up was for 41.3 months. Postoperative radiological assessment revealed that the implanted HA was well incorporated into the surrounding host bone in all patients. Two patients suffered fractures in the postoperative period. Two patients complained of pain associated with HA in the soft tissues, but this diminished within six months. No patient had local pain at the final follow-up. Recurrence of the tumour was seen in three cases. Histopathological study of the implanted area showed removal of the HA by histiocytes and multinucleated giant cells, and the formation of much appositional bone. We conclude that HA is an excellent bone-graft substitute in surgery for benign bone tumours.
We have studied the correlation between the prevention of progressive collapse and the ratio of the intact articular surface of the femoral head, after transtrochanteric rotational osteotomy for osteonecrosis. We used probit analysis on 125 hips in order to assess the ratio necessary to prevent progressive radiological collapse over a ten-year period. The results show that a minimum postoperative intact ratio of 34% was required. This critical ratio may be useful for surgical planning and in assessing the natural history of the condition.
In about 50% of cases, osteonecrosis of the femoral head is known to occupy more than one site. There is controversy as to whether a single focus may increase in size. We have reviewed 606 consecutive femoral heads which had been surgically removed for osteonecrosis. Extension of osteonecrosis was observed in only two (0.3%) and was confirmed histopathologically by the enlargement of the necrotic segment beyond the repair zone formed for the primary necrosis into the adjacent, previously uninvolved bone. In both cases, the necrotic regions were wedge-shaped and occupied over 80% of the femoral head. It appears that an increase in size is extremely rare and that osteonecrosis is due to a single event. Our findings may be of value in assessing the use of joint-salvage procedures for osteonecrosis of the femoral head.
Superior labral tears of the shoulder involve the biceps tendon and labrum complex which may be detached, displaced inferiorly, and interposed between the glenoid and the humeral head. We have treated ten young athletes with painful shoulders due to this lesion by arthroscopic stapling. Arthroscopy at the time of staple removal, after three to six months, showed that all the lesions had been stabilised. Clinical review at over 24 months showed an excellent or good result in 80%. The two relative failures were due in one to residual subacromial bursitis, and the other to multidirectional shoulder instability. Arthroscopic stapling can restore the shoulder anatomy, and it is recommended for active adolescent athletes with this lesion.
Excision of the lunate was performed for 18 patients with Kienbock's disease; 14 were followed up for an average of almost 12 years. Carpal collapse progressed with time, but rearrangement of the remaining carpal bones preserved a satisfactory range of movement and grip strength. Degenerative changes were not severe. All the patients had relief of pain, were able to carry out their normal activities, and all but two could perform strenuous activities.
