Kinematic radiography of the hip joint after hip resurfacing arthroplasty

This study aimed to evaluate the usefulness of dynamic radiography using a dynamic flat-panel detector (FPD) system after hip resurfacing arthroplasty (HRA). A total of 32 hips of 26 patients who underwent HRA were included. Sequential images of active abduction in the supine position and flexion in the 45° semilateral position were obtained using the FPD system. We examined the imaging findings of impingement between the acetabular component and femoral neck with cooperative motion at maximal exercise. Moreover, the central component coordinate of the acetabulum and femoral head sides was measured. For abduction motion, impingement was detected in two (6.3 %) hips between the superior portion of the femoral neck and acetabular component. For flexion motion, impingement was detected in 19 (59.4 %) hips. There were no findings of subluxation between the acetabular component and femoral neck after impingement, but cooperative motion of lumbar and pelvic flexion was observed. There was no significant difference in the center-to-center distance regardless of the presence or absence of impingement. Detailed postoperative kinematics of the hips after HRA showed that the proposed dynamic FPD system could reveal acquired impingement and cooperative motion as dynamic images and possibly reveal findings that would be unobservable using static images.     

Complications following hip joint prosthesis

Complications seen after long-term follow-up examinations of total hip replacement should be treated immediately and completely. In the past decade a considerable increase in revisions has been noted. Radiographic assessment may be regarded as an effective means in diagnosing prosthetic complications from the surgeon's point of view. Examples are given. The difficulties in radiographic assessment of complications after cementless implantation or cemented prostheses without contrast media are mentioned. Prosthesis-related complications, such as mechanical loosening, infection with and without loosening, fatigue fractures and wear, fractures of the femur or pelvis, dislocations and surgical failures, are illustrated, as are clinical courses with gross loss of bone stock after repeated surgery and delayed revisions. Complications not related to the prosthesis such as periarticular ossification, muscle deficiencies, and nervous and vascular lesions are also explained using examples.     

Intravenous methylmethacrylate following cemented total hip arthroplasty

Both cemented and noncemented techniques have been used for total hip arthroplasty (THA). Each technique has advantages and disadvantages. Among the disadvantages of cemented THA are several perioperative complications, such as intraoperative cardiac or respiratory failure and hypotension, called cement implantation syndrome, and extrusion of cement beyond the confines of the medullary canal. Cement extrusion can be the result of overreaming of the femoral canal and cortical perforation. This is a worrisome finding, as the risk of subsequent femoral fracture at the site of perforation is increased. Extruded cement, however, does not always indicate a problem. Extruded cement located within the femoral venous system, intravenous methylmethacrylate, for example, is not associated with long-term complications. While uncommon, it is important to differentiate this finding from the more serious cortical perforation.We report four examples of intravenous methylmethacrylate following THA and describe the imaging features that allow differentiation of this entity from the more significant finding of cortical perforation.     

Bone imaging after total replacement arthroplasty of the hip joint

Bone imaging was done in patients after total replacement arthroplasty of the hip joint every 3rd month using ^99mTc-HEDP and ¹⁸F. Uptake ratios were estimated over cup/normal hip and femur prosthesis/normal thigh.Ratios decline rapidly and reach a stable level 6–9 months, postoperatively. Eight cases of late infection were predicted correctly 1–3 months before any radiologic evidence was present. In four cases there had been false-positive results with ^99mTc-HEDP while ¹⁸F gave always correct information except in cases of soft tissue inflammation. Here both ^99mTc-HEDP and ¹⁸F ratios were elevated.The early diagnosis of late complications after replacement arthroplasty seems to be possible. The clinical significance, however, is low: only one out of eight patients with manifest infection is still on conservative treatment. Bone imaging should be done to exclude late infection as a cause of pain after total replacement arthroplasty of the hip joint only.Presented in part at the 22nd meeting of the Society of Nuclear Medicine, Philadelphia, Pa, June 17, 1975     

全髋关节置换术中髋关节偏心距重建对临床效果的影响

目的探讨全髋关节置换(THA)术中偏心距的恢复和重建在髋关节软组织张力平衡中的作用,分析重建髋关节偏心距与术后双下肢不等长以及髋关节功能恢复的关系。方法随机选择2008年1月~2012年5月收治的单侧THA患者98例,采用髋关节后外侧入路。全部使用Depuy(强生)公司(Pinnacle Acetabular System)髋系统和Corail人工关节柄。手术前后影像学检查:骨盆前后位X线片,髋关节三维CT扫描,双下肢全长X线片;测量双下肢全长、股骨偏心距的长度、髋臼偏心距的长度、髋关节外展肌力矩关节偏心距和其他指标的相关性。结果 (1)髋关节偏心距与髋关节外展肌力矩有正相关性(r=0.558,P0.001);(2)髋关节术后的活动度Harris评分与髋关节偏心距具有明显的回归相关关系(r=0.439,P0.001);(3)髋关节偏心距的重建对双下肢长度的影响存在着显著的意义(χ2=4.83,P0.01)。结论 THA术中偏心距的重建,可增加髋关节外展肌力矩和髋关节的活动度,与功能的改善及稳定性增加呈正相关。     

Dynamic stability during walking following unilateral total hip arthroplasty

The purpose of this study was to examine dynamic stability, defined as the vertical projection of the center of mass (COM) to the base of support (BOS) mediolaterally during walking in 16 healthy and 16 unilateral total hip arthroplasty (THA) persons. There was a significant effect of side for double limb support (DLS) for the healthy group and between groups but not significant for single limb support. The dynamic stability pattern for the THA group was to hold the COM in the midline during a longer DLS phase demonstrating a different motor control strategy compared to healthy adults.     

Hip arthroscopy in patients with painful hip following resurfacing arthroplasty

Purpose  

Determining the etiology of persistent groin pain after hip resurfacing arthroplasty (HRA) can be very challenging, even for the experienced surgeon. The purpose of the present study was to evaluate the use of hip arthroscopy as a diagnostic and therapeutic tool for the painful hip following resurfacing arthroplasty.     

Arthrography of the temporomandibular joint: a simple technique

The problem of the patient with the painful clicking temporomandibular joint is one of the most difficult to manage in oral surgical practice. Traditional methods of treatment have been largely empirical and have included the use of analgesics, muscle exercises, psychotherapy, condylar osteotomy and tooth grinding. Temporomandibular joint arthrography offers a method of accurately assessing internal derangements of the joint in order to select those patients for whom surgical reconstruction is appropriate.     

Persistent non-specific FDG uptake on PET imaging following hip arthroplasty

Hip arthroplasty is a common surgical procedure, but the diagnosis of infection associated with hip arthroplasty remains challenging. Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) has been shown to be a promising imaging modality in settings where infection is suspected. However, inflammatory reaction to surgery can result in increased FDG uptake at various anatomic locations, which may erroneously be interpreted as sites of infection. The purpose of this study was to assess the patterns and time course of FDG accumulation following total hip replacement over an extended period of time. Firstly, in a prospective study nine patients with total hip replacement were investigated to determine the patterns of FDG uptake over time. Three FDG-PET scans were performed in each patient at about 3, 6 and 12 months post arthroplasty. Secondly, in a retrospective analysis, the medical and surgical history and FDG-PET imaging results of 710 patients who had undergone whole-body scans for the evaluation of possible malignant disorders were reviewed. The history of arthroplasty and FDG-PET findings in the hip region were reviewed for this study. Patients with symptomatic arthroplasties or related complaints during FDG-PET scanning were excluded from the analysis. During the entire study period, all nine patients enrolled in the prospective study were demonstrated to have increased FDG uptake around the femoral head or neck portion of the prosthesis that extended to the soft tissues surrounding the femur. Among the patients reviewed in the retrospective study, 18 patients with a history of 21 hip arthroplasties who were asymptomatic at the time of FDG-PET scan met the criteria for inclusion. The time interval between the hip arthroplasty and the FDG-PET study ranged from 3 months to 288 months (mean+/-SD: 80.4+/-86.2 months). In 81% (17 of 21) of these prostheses, increased FDG uptake could be noted around the femoral head or neck portion of the prosthesis. The average time interval between arthroplasty and FDG-PET scan in these patients was 71.3 months. In only four prostheses (19%, 4 of 21) was no abnormally increased FDG uptake seen around the prostheses or adjacent sites. The average time interval in these patients was 114.8 months. It is concluded that following hip arthroplasty, non-specifically increased FDG uptake around the head or neck of the prosthesis persists for many years, even in patients without any complications. Therefore, to minimize the number of false-positive results for infection with PET studies obtained to evaluate a painful hip prosthesis, caution should be exercised when interpreting FDG uptake around the head or neck portion of the prosthesis.     

99Tcm-MDP显像用于人工髋关节置换术后关节感染的鉴别诊断

目的 探讨99Tcm-MDP显像用于髋关节置换术后关节感染与无菌性假体松动鉴别诊断的适合方法.方法 回顾性分析2008年2月至2011年8月间74例人工髋关节置换术后出现关节疼痛的患者资料,其中男32例,女42例,年龄(64.3±11.2)岁.所有患者均行99Tcm-MDP血流、血池和骨骼三时相显像及血清C反应蛋白和血红细胞沉降率测定.99Tcm-MDP显像分别以假体周围软组织放射性浓聚、假体周围骨骼放射性浓聚或两者同时存在作为关节感染的诊断依据;无上述阳性表现者即认为关节疼痛由无菌性假体松动所致.依据最终临床诊断,采用x2检验比较99Tcm-MDP显像中骨骼相、血流-血池相、血清学检查结果间诊断效能的差异.结果 74例患者中,有症状关节74个,其中感染关节24个,无菌性假体松动50个.诊断关节感染的灵敏度和特异性:血流-血池相分别为91.7％(22/24)和90.0％ (45/50),骨骼相分别为70.8％ (17/24)和48.0％ (24/50),血清C反应蛋白分别为62.5％ (15/24)和78.0％ (39/50),血红细胞沉降率分别为62.5％ (15/24)和76.0％ (38/50).血流-血池相对假体周围感染诊断的准确性优于单纯骨显像[90.5％ (67/74)和55.4％ (41/74);x2=23.159,P＜0.001],也优于血清C反应蛋白[73.0％(54/74) ;x2 =7.656,P＜0.05]和血红细胞沉降率[71.6％(53/74);x2 =8.633,P＜0.05]检测.结论 在髋关节置换术后关节感染与无菌性假体松动鉴别诊断中,99Tcm-MDP血流-血池相具有较高的临床价值,建议作为常规检查方法.     

Bone imaging after total replacement arthroplasty of the hip joint. A follow-up with different radiopharmaceuticals.

Bone imaging was done in patients after total replacement arthroplasty of the hip joint every 3rd month using 99mTc-HEDP and 18F. Uptake ratios were estimated over cup/normal hip and femur prosthesis/normal thigh. Ratios decline rapidly and reach a stable level 6-9 months, postoperatively. Eight cases of late infection were predicted correctly 1-3 months before any radiologic evidence was present. In four cases there had been false-positive results with 99mTc-HEDP while 18F gave always correct information except in cases of soft tissue inflammation. Here both 99mTc-HEDP and 18F ratios were elevated. The early diagnosis of late complications after replacement arthroplasty seems to be possible. The clinical significance, however, is low: only one out of eight patients with manifest infection is still on conservative treatment. Bone imaging should be done to exclude late infection as a cause of pain after total replacement arthroplasty of the hip joint only.     

Imaging of hip arthroplasty

The imaging evaluation of the prosthetic hip begins with radiography, but arthrography, aspiration, scintigraphy, sonography, CT and MR imaging all have roles in the evaluation of the painful prosthesis. This article will review the appearance of normal hip arthroplasty including hemiarthroplasty, total arthroplasty, and hip resurfacing, as well as the appearances of potential complications such as aseptic loosening and osteolysis, dislocation, infection, periprosthetic fracture, hardware failure, and soft tissue abnormalities.     

Imaging of hip arthroplasty

Radiography is the mainstay of the imaging evaluation of the prosthetic hip, but arthrography, aspiration, scintigraphy, sonography, computed tomography, and magnetic resonance imaging all have roles in the evaluation of the painful prosthesis. This article reviews the appearance of normal hip arthroplasty as well as the appearances of potential complications.     

Relevance of orthostatic posturography for clinical evaluation of hip and knee joint arthroplasty patients

In order to verify whether orthostatic posturography (OP) can support clinical assessment of total hip (THA) and knee arthroplasty (TKA), 81 subjects with THA and 100 with TKA were recruited and compared with 59 healthy volunteers. All patients were tested one or two days prior to surgery; 42 subjects (20 THA and 22 TKA) were tested again after six months, and 34 (14 THA and 20 TKA) yet again after 12 months. OP was performed using a Kistler 9286A piezoelectric force plate and the following postural parameters (PPs) were adopted on account of their functional meaning: mean velocity and the root mean square of the distance of the centre of pressure (CoP), sway area, and 95% of the CoP power frequency. Eye condition and fatigue related to the test duration were also examined. The three most meaningful PPs were identified and a logarithmic transformation was then applied to these, as well as standardization. Almost all the PP values were higher preoperatively in the patients as compared with the healthy subjects and it was possible to detect many statistically significant differences between patients and healthy subjects. However, when examining the 181 subjects at the preoperative stage, the PPs did not show congruence with the clinical scores as well as they did during follow-up. Therefore, the use of the OP is not recommended to monitor patients undergoing THA or TKA.     

Accuracy of CT-guided joint aspiration in patients with suspected infection status post-total hip arthroplasty

Objective

To determine the accuracy of guided computed tomography aspiration in the detection of septic hip prosthesis before surgery.

Materials and Methods

Sixty-three patients (35 women and 28 men; age range, 29?C86?years; mean age, 71?years) with clinically suspected septic hip prosthesis were prospectively studied with independent review board (IRB) approval. Volume and microbiological cultures of aspirated fluid and several computed tomography imaging findings such as periprosthetic fluid collections, prosthetic acetabular malposition, and heterotopic ossification were analyzed. All patients underwent revision surgery and infection was finally diagnosed in 33 patients.

Results

Statistical comparative analysis was performed comparing computed tomography aspiration and surgical findings (95% CI; level of significance at P?=?0.05 two-sided) with 70% sensitivity, 100% specificity, 84% accuracy, 100% positive predictive value, and 75% negative predictive value. Using Fisher??s exact test, the presence of periprosthetic fluid collections (P?=?0.001), prosthetic acetabular malposition (P?=?0.025) and aspirated fluid volume (P?=?0.009) were significantly higher in infected than in non-infected prostheses, whereas heterotopic ossification was not (P?=?0.429).

Conclusion

Computed tomography aspiration is accurate to preoperatively diagnose septic hip prosthesis on the basis of volume and bacterial cultures of aspirated joint fluid. Furthermore, imaging findings such as periprosthetic fluid collections and prosthetic acetabular malposition strongly suggest infected prosthesis.     

Small joint arthroplasty

There is little published on the radiology of small joint arthroplasty when compared with the commonly performed hip or knee replacement. The types of joint replacement, their clinical efficacy, and the expected radiographic appearances are reviewed for each of these upper and lower extremity joints. Potential complications and their radiographic appearances are presented.     

Utility of percutaneous joint aspiration and synovial biopsy in identifying culture-positive infected hip arthroplasty

Purpose

Percutaneous synovial biopsy has recently been reported to have a high diagnostic value in the preoperative identification of periprosthetic infection of the hip. We report our experience with this technique in the evaluation of patients undergoing revision hip arthroplasty, comparing results of preoperative synovial biopsy with joint aspiration in identifying an infected hip arthroplasty by bacteriological analysis.

Materials and methods

We retrospectively reviewed the results of the 110 most recent revision hip arthroplasties in which preoperative synovial biopsy and joint aspiration were both performed. Revision surgery for these patients occurred during the period from September 2005 to March 2012. Using this study group, results from preoperative cultures were compared with preoperative laboratory studies and the results of intraoperative cultures. Synovial aspiration was done using an 18- or 20-gauge spinal needle. Synovial biopsy was done coaxially following aspiration using a 22-gauge Chiba needle or 21-gauge Sure-Cut needle. Standard microbiological analysis was performed on preoperative synovial fluid aspirate and synovial biopsy. Intraoperative tissue biopsy bacteriological analysis results at surgical revision were accepted as the “gold standard” for the presence or absence of infection.

Results

Seventeen of 110 (15 %) of patients had intraoperative culture-positive periprosthetic infection. Of these 17 cases, there were ten cases where either the synovial fluid aspiration and/or the synovial biopsy were true positive (sensitivity of 59 %, specificity of 100 %, positive predictive value of 100 % and accuracy of 94 %). There were seven cases where aspiration and biopsy results were both falsely negative, but no false-positive results. Similar results were found for synovial fluid aspiration alone. The results of synovial biopsy alone resulted in the identification of seven infected joints with no false-positive result (sensitivity of 41 %, specificity of 100 %, positive predictive value of 100 %, and accuracy of 91 %).

Conclusions

Standard microbiological analyses performed on percutaneous synovial biopsy specimen during the preoperative evaluation of patients undergoing revision hip arthroplasty did not improve detection of culture-positive periprosthetic infection as compared to synovial fluid aspiration alone.     

The role of ultrasound in the assessment of post-operative complications following hip arthroplasty

Hip arthroplasty is one of the most commonly performed orthopedic procedures. Clinicians can be faced with the diagnostic dilemma of the patient presenting with a painful hip following arthroplasty and satisfactory post-operative radiographs. Identifying the cause of symptoms can be challenging and ultrasound is increasingly being utilized in the evaluation of potential soft tissue complications following hip surgery. In this article, we describe the common surgical approaches used during hip arthroplasty as this can influence the nature and location of subsequent complications. A review of the literature is presented along with the imaging appearances frequently encountered when imaging this patient population.     

Ultrasonography after hip arthroplasty

Ultrasonography was performed in 55 patients who had total Charnley hip arthroplasties. Effusions were identified in 19 patients and confirmed in all but 3 by arthrocentesis or at surgery. Aspirations were performed in 5 and demonstrated infection in 2. It is concluded that ultrasound is a valuable noninvasive method for assessing painful hip arthroplasty. It can demonstrate the presence of effusion, which should be aspirated to exclude infection.