Bulletin of the NYU hospital for joint diseases最新文献

Background: Although the effect of Staphylococcus aureus (SA) decolonization on surgical site infection (SSI) rates has been studied, patient tolerance and acceptance of these regimens has not been assessed. Surgical patients at our hospital's Pre-Admission Testing Clinic (PAT) receive SA reduction protocols instructing the preoperative use of chlorhexidine gluconate (CHG) soap and intranasal mupirocin ointment (MO). Certain insurers do not cover MO costs resulting in out of pocket (OOP) expenses for some patients.

Objective: This study assessed patient attitudes and compliance with our hospital's SA decolonization regimen.

Methods: One-hundred-forty-six patients received surveys. Descriptive statistics were used for analysis.

Results: Of respondents fitting inclusion criteria, 81% followed the MO protocol (MO users) while 89% followed the CHG protocol (CHG users). Fifty-four percent of MO users reported OOP expenses and 13% reported a hard or very hard financial burden. Ninety-three percent of CHG users reported the protocol was easy or very easy to follow.

Conclusion: Eighty-one percent of patients receiving the SA protocol were fully compliant despite cost or difficulty obtaining MO. Given these barriers and some difficulty with CHG application, we hypothesize compliance may be improved if MO is provided to patients without OOP expenses and if the CHG application method is simplified.

Spontaneous osteonecrosis of the knee (SPONK) and osteo necrosis in the postoperative knee (ONPK) are two clinical entities that have the potential to cause significant morbidity in affected patients. In addition to the knowledge of the patient population at risk and the classic presentation and imaging characteristics of SPONK and ONPK, the treating orthopaedic surgeon needs to maintain a high index of suspicion for these disorders since early diagnosis and treatment may allow for an improved clinical outcome. The following review presents the current knowledge regarding these two pathological processes of the knee.

The glenohumeral joint is the most commonly dislocated joint in the body. The prevalence of this condition and the instability that may result from it has been a focus of diagnosis and treatment since the original description of the Bankart lesion in 1923. Now, with the introduction of MRI, lesions causing anterior shoulder instability can be diagnosed more accurately. This has led to improved understanding of the pathoanatomy that must be addressed and corrected during surgical repair. Initial attempts at arthroscopic treatment, including staple repair, transosseus suture repair, rivets, and thermal capsulorraphy were fraught with complications and unacceptably high recurrence rates. The development of arthroscopic suture anchors have revolutionized the treatment of anterior shoulder instability, such that arthroscopic management is now the standard of care. In the hands of experienced surgeons, outcomes for arthroscopic treatment of shoulder instability now approaches the success of open treatment.

A fracture construct, representing a worst-case model of a comminuted intertrochanteric fracture, was created in order to compare the fixation stability of two different cephalomedullary nails: one where the lag screw can telescope within itself to achieve displacement of the head-neck fragment, and the other where the solid lag screw slides only. After nail fixation, the models were loaded and then cycled, and positions of the head-neck fragment and lag screw were determined. Both nails similarly acted to limit motion of the head-neck fragment by the sliding of their lag screws, causing impingement of the fragment against the nail. Fragment movement was achieved with significantly less force with the telescoping lag screws, which also showed no final lateral projection from the nail. This was in contrast to the solid lag screws that demonstrated lateral projection in all cases.

Unlabelled: Uncemented fixation of implants to bone is a proven technology in traditional hip arthroplasty surgery. However, cement fixation is currently the standard method for the femoral component in hip resurfacing. The purpose of this study was to evaluate the performance of uncemented fixation of the femoral component in the first 100 fully porous-coated metal-on-metal hip resurfacing arthroplasties at a minimum follow-up of 2 years.

Materials and methods: From March to October 2007, 100 consecutive uncemented metal-on-metal hip resurfacing arthroplasties in 95 patients (74 males and 21 females) were implanted by the same surgeon, using bone ingrowth technology for both femoral and acetabular components. The posterior minimally invasive approach was utilized in all cases. The primary diagnosis was osteoarthritis in 72% of cases, but other diagnoses were not excluded for the purposes of this study. The mean femoral component size was 51 ± 4 millimeters, and patients were not excluded for small component size.

Results: The mean follow-up was 2.9 ± 0.2 years. The mean pre-operative Harris hip score was 57 ± 13 and improved to 96 ± 6 at the final follow-up visit. The mean UCLA activity score was 8 ± 2. There were two failures (2%): one femoral neck fracture at 2 months and one femoral component loosening at 12 months postoperatively.

Conclusion: The study demonstrated that fully porous-coated femoral resurfacing components have equivalent results to those reported for cemented femoral components at short-term follow-up. This suggests that the femoral head can reliably achieve bone ingrowth into a fully porous-coated femoral component. This encourages us to continue utilizing this bone ingrowth technique as an alternative to cement in this young and active patient group. Long-term follow-up will be needed.

Unlabelled: Two important issues affecting the outcome of total hip arthroplasty have been dislocation and wear, despite excellent clinical results. Larger femoral heads have had success in decreasing dislocation rates; however, there are concerns regarding the subsequent use of thinner polyethylene liners, and their effects on wear rates. Historically, high stresses on thin polyethylene bearings have caused concerns, including rim cracking and catastrophic implant failure with polyethylene thicknesses less than 5 millimeters. Recently, sequentially cross-linked and annealed polyethylene has been shown to reduce the wear rate significantly, compared to conventional ultra-high-molecular-weight polyethylene (UHMWPE) in vitro. The purpose of this study was to analyze the clinical and radiographic outcomes in a cohort of patients treated with sequentially cross-linked and annealed polyethylene bearings with a nominal thickness of 3.8 millimeters. Outcomes were compared to a similar cohort of patients who were treated with total hip arthroplasty during the same time period and utilizing the same polyethylene thickness of 5.8 millimeters or greater.

Materials and methods: We identified 50 patients (53 hips) who had a minimum 2-year clinical and radiographic follow-up after a standard total hip arthroplasty, performed with a thin, sequentially cross-linked and annealed polyethylene bearing surface. There were 15 males and 35 females, with a a mean age of 60 years (range, 16 to 93 years) and a mean body mass index of 28.6 kg/m² (range, 17.2 to 47.5 kg/m²). Overall survivorship was compared to a cohort of 50 patients (53 hips) treated with total hip arthroplasty during the same time period, utilizing the same polyethylene of 5.8 millimeters or greater thickness. Radiographic analysis of polyethylene wear was performed on a subset of 26 hips, using a previously validated two-dimensional computer-aided technique. Volumetric wear was calculated and subsequent annual volumetric and linear wear rates were derived for each patient in the study cohort. Additionally, radiographic analysis was performed to assess for any progressive radio-lucencies or malalignment.

Results: The overall survivorship of the study cohort was 100%, compared to a 96% survivorship in the comparison group (two failures due to infection). The mean Harris hip scores in the thin polyethylene cohort improved from 43 points (range, 10 to 67 points) pre-operatively to 91 points (range, 69 to 100 points) postoperatively. Upon radiographic review, no malalignment, radiolucencies, or polyethylene fracture was noted in the study cohort. The mean volumetric wear rate was 0.4122 mm³/year (range, 0.2311 to 0.7310 mm³/year), and the mean linear wear rate was 0.0004 mm/year (range, 0.0002 to 0.0007 mm/year) for the thin polyethylene group. The mean volumetric wear was 0.8839 mm³ (range, 0.4621 to 1.5839 mm³) for this cohort. Excellent cl

Unlabelled: The objective of this study was, in chondrosarcoma (CHS) of the femur, to evaluate by radiologic-pathologic correlation, the degree of tumor growth, cortical destruction, periosteal reaction, and soft tissue extension present.

Materials and methods: Eight cases of histologically proven CHS of the femur were studied. All cases were resected, evaluated histologically with coronal slabs, and compared with radiographs and magnetic resonance imaging (MRI) scans. In two resected specimens, the tumors were studied in more detail; along with coronal slabs, axial sections of the remaining anterior and posterior halves of both tumors were taken, and the bone specimens were X-rayed and examined histologically.

Results: CHS initially involved the medullary cavity and subsequently destroyed the cortex; first, by endosteal scalloping and, second, by subsequent invasion and destruction of the cortex. During this process, there was periosteal new bone formation (PNBF), with increased cortical thickness, the degree of which often correlated with the degree of cortical destruction. In the areas of cortical thickening of three cases, a "grey line" was seen on MRI that separated the cortex from the periosteal new bone; the line, in reality,is a space between the two structures. The presence of this line suggests that the tumor does not extend beyond the cortex. PNBF occurred in all cases and varied in thickness. It frequently developed independent of direct periosteal tumor involvement. The periosteum of one case contained porotic bone with interposed marrow fat, which was easily misinterpreted as tumor extension on MRI. Expansion and remodeling of the femoral diaphysis in CHS, with widening of the medullary cavity, is usually due to extensive cortical destruction with PNBF. Soft tissue extension was present in five cases and apparently occurred by two different mechanisms: direct tumor destruction of the cortex and periosteum, with extension into the soft tissues; and subtle MRI occult tumor permeation through the periosteum. As far as we know, a first literature histologic description of the thickened CHS periosteum also was accomplished.

Conclusion: PNBF is a common imaging manifestation of CHS of the femur, which correlated with the degree of cortical destruction. A grey line between the cortex and periosteum is an MRI finding described in this study and may facilitate the evaluation of periosteal thickening and tumor invasion in CHS. PNBF often occurs in the absence of direct periosteal involvement. Periosteal imaging abnormalities suggestive of tumor infiltration should be interpreted with caution on MRI, and early soft tissue extension in CHS may be difficult to determine on MRI.

A systematic review and meta-analysis of trials comparing hip resurfacing to metal-on-metal total hip arthroplasty was conducted to determine if there is a difference in serum metal ion levels in patients receiving these implants. EMBASE and MEDLINE databases were searched from inception to December 2010 for all trials involving the use of these devices. Eligibility for inclusion in the review were studies with 1. comparative trials that were both retrospective and prospective; 2. inclusion of a treatment arm receiving hip resurfacing; 3. inclusion of a treatment arm receiving metal-on-metal total hip arthroplasty; and 4. analysis of chromium and cobalt ions, or either, in patient serum or whole blood at a minimum of 1 year after implantation. The literature search identified 87 potential studies, of which 10 met the inclusion criteria. Pooled mean differences were calculated for serum cobalt and chromium ion levels. Mean differences for serum cobalt and chromium metal ions were not significantly different between hip resurfacing and metal-on-metal total hip arthroplasty patients, although there was a tendency for lower serum cobalt ion levels in patients receiving hip resurfacing. Larger prospective randomized trials are required to better substantiate a difference in metal ion levels occurring between these implants.

Acetabular dysplasia is among the most frequent causes of secondary osteoarthritis (OA) of the hip. While hip arthrolasty is a valid option in elderly patients, young and active patients are likely to outlive their implants and therefore may require a different approach. During the last 20 years, the emphasis of these osteotomies shifted from the femoral to the acetabular side, with the Bernese periacetabular osteotomy being one of the most frequently and successfully used techniques today. The procedure combines a polygonal juxta-articular osteotomy using a modified Smith-Peterson approach. During refinement of the technique, the principle osteotomy steps remained unchanged, while the soft-tissue dissection has been modified, in that the abductors are not detached from the iliac wing. Due to a better appreciation of hip deformities, other indications for this technique have continuously evolved over time.