Background

A stem sitting proud (SP) or that above the final rasp position remains in some patients who undergo hip replacement using proximally coated tapered wedge stems. Surgeons may face challenges providing the best fit due to unpredictable stem seating. Zimmer Inc. introduced a new rasp to solve this issue but the clinical results of this rasp have not yet been published. Therefore, we aimed to address the following: 1) What is SP incidence using a proximally coated cementless tapered wedge stem? 2) Does the new rasp system improve seating height? 3) What are the risk factors of SP?

Introduction

Acetabular dysplasia cause hip joint osteoarthritis(OA) by change hip mechanism. However, to our best knowledge, no studies have been published using prospectively collected data from asymptomatic young age volunteers, precise radiographic method. The purpose of this study is to evaluate the prevalence of hip dysplasia in asymptomatic Korean population as one of the most important risk factor of hip OA.

We report a case of fatal heart failure caused by cobalt intoxication after revision THR in the patient who successfully underwent re-revision THR. 53-year old male presented to emergency room in our hospital with progressive shortness of breath. Symptom was started about 6 months ago so he visited local hospital. He worked up for worsening dyspnea. Simple chest radiograph and enhanced heart MRI study were performed and they showed bilateral pericardial and pleural effusion. There was no evidence of ischemic change. Transthoracic echocardiogram showed the evidence of heart failure, left ventricular ejection fraction(EF) was 40%. He was admitted at local hospital and started on vasopressors but urine output was decreased and follow-up echocardiogram showed a 25% of EF. Patient recommended heart transplantation and transferred our hospital emergency room. He underwent sequential bilateral total hip arthroplasties using CoP bearing surfaces. At 12 years postoperatively, he presented to the other hospital with acute onset of left hip pain. He was diagnosed ceramic head fracture on his left hip. Head and liner change revision surgery was performed using Cobalt-Chrome alloy 28mm metal head and Protruded cross-linked polyethylene liners. In our hospital, the patient admitted cardiovascular department of internal medicine. Patient complained nonspecific fatigue and general weakness but had no other symptoms such as visual and hearing loss, cognitive dysfuction. During work-up, patient presented progressive left hip pain and complaint of discomfort for the mass on the left groin. He also complained Left leg weakness and numbness. Simple radiograph and enhanced CT study was done. Simple radiograph image shows radiodense area around the hip joint and radiologist suspected heterotopic ossification. The cardiovascular department consulted orthopedic department. In the image findings showed huge mass combined hemorrhagic component lining acetabular component extending psoas compartment and eccentric wear on cobalt-chrome alloy metal head. Also highly radiodense material was seen around neck inferor portion and severly deformed metal head was seen. It was highly suspected that metal related granuloma, which means severe metallosis. Performed heavy metals screen, cobalt levels were 397,800 μg/Land chrome levels were 236,000 μg/L suggesting cobalt toxicity. Hip joint aspiration was done for decompression as radiologic intervention and EDTA (ethylenediamine tetraacetate) chelation therapy started immediately. After 10 cycle chelating therapy, metal level was lowered cobalt levels by 255.2μg/L and chrome levels by 39.5 μg/L. When hospital day after 134, Medical condition of the patient was getting improved, we underwent revision surgery using ceramic on ceramic bearing surface. The patient discharged postoperative 79 days. Final heavy metals screen results were 27.79μg/L on cobalt and 22.17μg/L on chrome. Although there were also reported a good clinical result of revision surgery using MoP bearing, and some surgeons reluctant to use CoC articulation because of concerns about re-fracture of ceramic. But take into account like this devastating complication after cobalt-chrome wear caused by remained ceramic particles, we should carefully select which bearing is safer.

Introduction

The use of open wedge high tibial osteotomy (OWHTO) to reduce knee pain by transferring weight-bearing loads to the relatively unaffected lateral compartment in varus knees and to delay the need for a knee replacement by slowing or stopping destruction of the medial joint compartment. To maintain the stability of OWHTO, the most common type of plate was T-Plate as the locking compression plate (LCP) concept. Anterior portion of T-Plate infringe patient's soft tissue resulted in some complications, whereas anatomical L-plate does not. To evaluate the structural stability of the anatomically contoured L-plate in the present study, the effect of weight bearing after osteotomy should be reviewed in the point of the stress of the plate and screws. We hypothesize that its stress path diverge through collateral portion of tibia and the stress level in screws lowered comparing to the result of T-plate presented in existing literature.

Introduction

Total knee arthroplasty (TKA) is a well proven surgical procedure. Squat and gait motions are common activities in daily life. However, squat motion is known as most dissatisfying motion in activities in daily life after total knee arthroplasty (TKA). Dissatisfaction after TKA might refer to muscle co-contraction between quadriceps and hamstrings. The purposed of this study was to develop squat and gait simulation model and analyses the contact mechanics and quadriceps and hamstring muscle stability. We hypothesized that squat model shows larger contact forces and lower hamstring to quadriceps force ratio than gait model.

It has been reported that the total steroid dose and acute rejection episodes after organ transplantation is one of the risk factors for the development of osteonecrosis of the femoral head (ONFH), and ONFH in steroid-iduced subgroup may progress more aggressively to femoral head collapse requiring total hip arthroplasty. Despite inherent medical co-morbidities of solid organ transplantation patients, most authors recently have reported successful outcomes of THAs in those patients. But there are few comparative studies on the outcome of THAs for ONFH after different organ transplantations. The purpose of this study was to evaluate and compare a single tertiary referral institution's experience of performing primary THAs in kidney transplantation (KT) and liver transplantation (LT) patients with specific focus on the total steroid dose, clinical outcomes, and relationship between ONFH and absence or presence of acute rejection (AR).

Between 1999 and 2010, 4,713 patients underwent organ transplantations (1,957 KT and 2,756 LT) and AR was occurred in 969 patients (20.6%) after transplantation. Among these patients, 131 patients (191 hips) underwent THA for ONFH, and they were retrospectively reviewed. In KT groups, there were 57 men and 36 women with a mean age of 43.7 years. In LT groups, there were 26 men and 13 women with a mean age of 50.4 years. We investigated the dose of steroid administration on both groups, the time period from transplantation to THA, Harris hips score (HHS), visual analogue scale (VAS) and complications. The mean follow up period was 8.1 years (range, 5 to 14 years).

One-hundred and thirty-one (2.8%) patients [93 KT and 38 LT] underwent THA after transplantation. The total steroid dose after transplantations was significantly higher in KT group (10,420 mg) than that in LT group (4,567 mg), but the total steroid dose in the first 2 weeks after transplantation was significantly higher in LT group (3,478 mg) than that in KT group (2,564 mg). Twenty-three (2.4%) patients (19 KT and 4 LT) who underwent THA had an episode of AR. In LT group, the total steroid dose in AR groups was significantly higher than that in non-AR groups, whereas in KT group, there was no significant difference of the total steroid dose between AR group and non-AR group. The rate of THAs for ONFH was similar in both groups (2.4% in AR group, 2.9% in non-AR group). The mean time period from transplantation to THA was 986 days for KT and 1,649 days for LT patients. Both groups showed satisfactory HHS and VAS at final follow up, revealed no differences between the groups.

The rate of THAs for ONFH was three times higher in KT patients than that in LT patients, but it was similar in both AR group and non-AR group. The total steroid dose was also higher in KT patients compared to LT patients. The clinical outcomes of THA were satisfactory with few complications in both KT and LT patients. Therefore, THAs seems to be a good option for the patients with symptomatic steroid-induced ONFH after KT and LT.

Few epidemiological studies from Asian countries have addressed this issue and reported that FAI is less prevalent in Asian population. The purpose of this study was to determine the prevalence of radiographic hip abnormalities associated with FAI in asymptomatic Korean volunteers. The authors hypothesized that the prevalence of FAI in Korean population would not be less than that in western population.

Two hundred asymptomatic volunteers with no prior hip surgery or childhood hip problems underwent three-view plain radiography (pelvis anteroposterior (AP) view, Sugioka view, and 45° Dunn view) of both hips. Cam lesions were defined as the presence of the following signs on each views: pistol-grip deformity, osseous bump at the femoral head-neck junction, flattening of the femoral head-neck offset, or alpha angle >50°. Pincer lesions were determined by radiographic signs, including crossover sign, posterior wall deficient sign, or lateral center-edge (CE) angle >40°. Only positive cases agreed by both observers were defined as true FAI-related deformities.

There were 146 male and 254 female hips, with a mean age of 34.7 years. On pelvis AP view, the prevalence of pistol grip deformity, bump, flattening, and alpha angle >50° was 1.3% (male 3.4%, female 0%), 0.8% (male 2.1%, female 0%), 0.8% (male 2.1%, female 0%), and 1.0% (male 2.7%, female 0%), respectively. On Sugioka view, the prevalence of bump, flattening, and alpha angle >50° was 9.8% (male 14.4%, female 7.1%), 13.5% (male 20.5%, female 9.4%), and 14.0% (male 26.7%, female 6.7%), respectively. On 45° Dunn view, the prevalence of bump, flattening, and alpha angle >50° was 8.0% (male 14.4%, female 4.3%), 17.5% (male 27.4%, female 11.8%), and 27.5% (male 44.5%, female 17.7%), respectively. The prevalence of cam lesion which was identified on at least one radiograph was 42.5% (male 62.3%, female 31.1%). The prevalence of cam lesion which was identified on ≥2 radiographs was 19.3% (male 30.8%, female 12.6%). The prevalence of cam type FAI (at least one cam lesion) was 2.0% (male 5.5%, female 0%) on pelvis AP view, 25.8% (male 37.0%, female 19.3%) on Sugioka view, and 35.8% (male 55.5%, female 24.4%) on 45° Dunn view. On pelvis AP view, the prevalence of crossover sign, posterior wall sign, and CE angle >40° was 20.0% (male 23.3%, female 18.1%), 20.8% (male 22.6%, female 19.7%), and 2.0% (male 2.7%, female 1.6%), respectively. The prevalence of pincer type of FAI (at least one pincer lesion) was 23.0% (male 27.4%, female 20.5%).

In asymptomatic Korean volunteers, the prevalence of cam type FAI was low on AP pelvis radiographs, whereas the prevalence of cam type FAI on Sugioka and 45° Dunn view was found to be comparable to that previously reported in Western populations. The prevalence of pincer type FAI in asymptomatic Korean volunteers was also comparable that in Western populations and was similar in both gender. Considering the high prevalence of FAI morphologic features on plain radiographs in asymptomatic Korean populations, it is also important to determine whether FAI is a cause of hip pain when considering surgery in Asian patients.