Incidence and Factors Associated with Squeaking in Alumina-on-Alumina THA

Background  

The alumina-on-alumina bearing surface, which has a high wear resistance and a good biocompatibility, is widely used in THA but recently has been associated with squeaking. While various authors have reported factors associated with squeaking, they remain poorly understood.     

Large-diameter Delta Ceramic-on-ceramic Versus Common-sized Ceramic-on-polyethylene Bearings in THA

The higher failure rate of total hip arthroplasty (THA) in young, active patients remains a challenge for surgeons. Recently, larger-diameter femoral heads combined with an alumina matrix composite ceramic (BIOLOX Delta; CeramTec AG, Plochingen, Germany) articulation was developed to improve implant longevity and meet patients' activity demands while reducing the risk of component-related complications. The purpose of this study was to determine whether this new device may provide advantages for young, active patients. A prospective, randomized, controlled trial was conducted on 93 patients (113 THAs) with more than 3 years of follow-up. Patients were randomly divided into a study group (51 THAs) with a 36-mm Delta ceramic-on-ceramic (COC) articulation and a control group (62 THAs) with a common-sized alumina ceramic head on polyethylene liner (COP) articulation. Clinical and radiographic results were collected to compare the outcomes and complications, including implant-related failures, osteolysis, and noises. The large-diameter Delta COC articulation provided greater range of motion improvement (6.1° more), similar Harris Hip Scores, and similar complication rates compared with the alumina COP articulation. This study suggests that in the short term, the large-diameter Delta COC articulation results in better range of motion with no higher complication rates; however, mid-term (8-10 years) or longer follow-up is necessary to determine its superiority in young, active patients.     

Incidence of Modern Alumina Ceramic and Alumina Matrix Composite Femoral Head Failures in Nearly 6 Million Hip Implants

Background

Because of improvements in ceramic materials and manufacturing, the incidence of ceramic failures has decreased over time. Recent concerns with corrosion have contributed to an increase in ceramic ball head utilization. The purpose of this study is to report the incidence of modern alumina bearing failures from a single major ceramic manufacturer in nearly 6 million hip implants and to identify trends in the modes of failure of these implants.

Squeaking in ceramic-on-ceramic hips: the importance of acetabular component orientation

Audible squeaking in total hip replacements with ceramic-on-ceramic bearings is a rare problem. Acetabular component orientation was compared for 17 squeaking hips and 17 matched controls. Ninety-four percent of control hips were in a range of 25 degrees +/- 10 degrees anteversion and 45 degrees +/- 10 degrees inclination, but only 35% of squeaking hips were in this range (P = .0003). Eight hips squeak with bending. Four hips squeak with walking, and 5 hips squeak after prolonged periods of walking. Hips that squeaked with walking had acetabular components that were more anteverted (40 degrees ) than hips that squeaked with bending (19 degrees ) (P = .001) or prolonged walking (18 degrees ) (P = .020). The hips started squeaking after an average of 14 months. Patients with squeaking hips were younger, heavier, and taller than patients with silent hips.     

CT Reveals a High Incidence of Osseous Abnormalities in Hips with Labral Tears

Background  

Acetabular labral tears are being diagnosed with increasing frequency and there is a growing consensus that these tears rarely occur in the absence of osseous abnormalities.     

High Incidence of Minor Chromosomal Variants in Teratozoospermic Males

Chromosomal analysis was performed on 109 males with teratozoospermia. Four cases of anomaly were found, including three cases of mosaic Klinefelter's syndrome and one balanced autosomal translocation. Among chromosomal heteromorphisms, 9qh+ was found in 25% of the patients. The fraction of malformed spermatozoa in the semen of the 9qh+ group is significantly higher than in the chromosomally normal group. It is speculated that heterochromatic variants like 9qh+ could be one of several unknown factors disturbing normal gametogenesis.     

Surgical procedures in the treatment of 784 infected THAs reported to the Norwegian Arthroplasty Register

Background and purpose

Controversies still exist regarding the best surgical procedure in the treatment of periprosthetic infection after total hip arthroplasty (THA). Based on data in the Norwegian Arthroplasty Register (NAR), we have compared the risk of re-revision after 4 different surgical procedures: 2-stage with exchange of the whole prosthesis, 1-stage with exchange of the whole prosthesis, major partial 1-stage with exchange of stem or cup, and minor partial 1-stage with exchange of femoral head and/or acetabular liner.

Methods

Between 1987 and 2009, 124,759 primary THAs were reported to the NAR, of which 906 (0.7%) were revised due to infection. Included in this study were the 784 revisions that had been performed by 1 of the 4 different surgical procedures. Cox-estimated survival and relative revision risks are presented with adjustment for differences among groups regarding gender, type of fixation, type of prosthesis, and age at revision.

Results

2-stage procedures were used in 283 revisions (36%), 1-stage in 192 revisions (25%), major partial in 129 revisions (17%), and minor partial in 180 revisions (23%). 2-year Kaplan-Meier survival for all revisions was 83%; it was 92% for those re-revised by 2-stage exchange procedure, 88% for those re-revised by 1-stage exchange procedure, 66% for those re-revised by major partial exchange procedure, and it was 76% for those re-revised by minor partial exchange. Compared to the 2-stage procedure and with any reason for revision as endpoint (180 re-revisions), the risk of re-revision increased 1.4 times for 1-stage (p = 0.2), 4.1 times for major partial exchange (p < 0.001), and 1.5 times for minor partial exchange (p = 0.1). With infection as the endpoint (108 re-revisions), the risk of re-revision increased 2.0 times for 1-stage exchange (p = 0.04), 6.0 times for major partial exchange (p < 0.001), and 2.3 times for minor partial exchange (p = 0.02). Similar results were found when the analyses were restricted to the period 2002–2009.

Interpretation

In the Norwegian Arthroplasty Register, the survival after revision of infected primary THA with 2-stage implant exchange was slightly superior to that for 1-stage exchange of the whole prosthesis. This result is noteworthy, since 2-stage procedures are often used with the most severe infections. However, debridement with exchange of head and/or liner but with retention of the fixed implant (minor revision) meant that there was a 76% chance of not being re-revised within 2 years.The risk of periprosthetic infection after total hip arthroplasty (THA) has decreased from 5–10% in the late 1960s to around 1% today (Lidgren 2001, Lidgren et al. 2003, Zimmerli and Ochsner 2003, Dale et al. 2009, Walenkamp 2009, Ong et al. 2009, Urquhart et al. 2010). In the last few years, however, some reports have indicated that there is an increasing incidence of revisions for infected THA (Kurtz et al. 2008, Dale et al. 2009, Pedersen et al. 2010).The optimum treatment of deep infection remains controversial (Toms et al. 2006). 2-stage exchange requires a minimum of 2 surgical procedures and a substantial period of reduced mobility. Removal of a well-fixed cemented prosthesis may also result in degradation of the bone stock and perioperative fracture (Langlais 2003, Ong et al. 2009, Bejon et al. 2010). A procedure with debridement, antibiotics, and implant retention (DAIR) with or without exchange of removable parts (i.e. liner and/or head), which is technically less demanding, could therefore be an attractive option for treatment of early deep infections, especially in elderly or frail patients (Giulieri et al. 2004, Trebse et al. 2005, Toms et al. 2006, Byren et al. 2009).In this paper, based on the data in the Norwegian Arthroplasty Register (NAR), we compared the risk of re-revision after the first surgical revision for deep infection of a primary THA by one of the following 4 surgical procedures: 2-stage exchange of the whole prosthesis, 1-stage exchange of the whole prosthesis, major partial 1-stage with exchange of stem or acetabulum, and minor partial 1-stage with exchange of acetabular liner and/or femoral head (Trampuz and Zimmerli 2006).     

Ceramic-on-ceramic bearings in hip arthroplasty: state of the art and the future

This systematic review of the literature summarises the clinical experience with ceramic-on-ceramic hip bearings over the past 40 years and discusses the concerns that exist in relation to the bearing combination. Loosening, fracture, liner chipping on insertion, liner canting and dissociation, edge-loading and squeaking have all been reported, and the relationship between these issues and implant design and surgical technique is investigated. New design concepts are introduced and analysed with respect to previous clinical experience.     

High Incidence of Donor-Reactive Delayed-Type Hypersensitivity Reactivity in Transplant Patients

Evidence of transplant recipient cellular sensitization towards donor antigens has rarely been directly measured. Rather, sensitization has been generally inferred by the presence of detectable allo-reactive or donor-reactive antibodies. In this study a newly developed delayed-type hypersensitivity assay was used to directly determine the incidence of post-transplant donor-reactive T-cell sensitization in a large cohort of kidney and simultaneous kidney-pancreas recipients. These results were compared with the presence of detectable circulating alloantibodies and with patient clinical outcome. We found an unexpectedly high incidence (52%) of donor-reactive delayed-type hypersensitivity reactivity in our study patients. Donor-reactive delayed-type hypersensitivity reactivity occurred at a much higher frequency than detectable alloantibodies (20%). Further, we found no correlation between the presence of alloantibodies and donor-reactive delayed-type hypersensitivity reactivity. We also found no correlation between the development of donor-reactive delayed-type hypersensitivity reactivity and the degree of donor and recipient HLA matching. Finally, the presence of detectable donor-reactive delayed-type hypersensitivity reactivity did not correlate with a worse clinical outcome at the time of these analyses. We conclude that in transplant recipients, the presence of circulating alloantibodies is a poor indicator of previous T-cell sensitization to donor antigens. We also conclude that our current immunosuppression strategies are relatively ineffective at blocking T-cell allosensitization, but are very effective at blocking the biological consequences of that allosensitization.     

High Incidence of Malignancy in Polyomavirus-Associated Nephropathy in Renal Transplant Recipients

Human polyomaviruses (PV), including JC and BK virus, have been reported to cause polyomavirus-associated nephropathy (PVAN), in renal transplant patients. PV infection has been demonstrated to be associated with malignancies in animals; however, the association between malignancy and viral infections in humans is not clear. We retrospectively reviewed our 864 (M:F = 502:362) kidney transplant patients over the past 25 years. We identified PVAN in 6 patients (0.69%), including BK nephropathy (n = 5) and JC nephropathy (n = 1). Three patients (50%) improved after reducing the immunosuppression, but 3 (50%) progressed to graft loss despite this reduction. Malignancy occurred in 5 out of the 6 patients (83%; P < .0001 compared with patients without PVAN), including transitional cell carcinoma (n = 2), renal cell carcinoma (n = 1), squamous cell carcinoma of skin (n = 1) and Kaposi sarcoma (n = 1). We concluded that kidney transplant patients with PVAN are at a significantly greater risk to develop malignancy. Whether this is due to a direct effect of PV infection or the result of overimmunosuppression remains to be determined in a future study.     

High Incidence of Perigraft Seroma Formation with Gelatin‐Coated Polytetrafluoroethylene Grafts

We reviewed the effectiveness of a gelatin‐coated polytetrafluoroethylene (PTFE) graft designed to reduce suture line bleeding and graft weeping. Twenty‐nine adults with end‐stage renal disease underwent implantation the graft (n = 30) in the arm. All had preoperative ultrasound vascular mapping to assess their options for an autogenous arteriovenous fistula and patients with a history of prior central venous devices or sternotomy underwent contrast venography. A 4‐ to 7‐mm tapered graft (n = 10) was used if the inflow artery was <4.0 mm in diameter, and a 6‐mm straight graft (n = 20) was used if the artery was ≥4.0 mm. Intraoperative volume flows were measured by duplex methodology. Precautions to prevent ultrafiltration and seroma development were taken. Eleven clinically significant seromas were detected in 30 sealed PTFE grafts (36.7%), 10 in the 6‐mm grafts (50%), and 1 in a 4‐ to 7‐mm graft (10%), a significant difference between graft types. There were no significant differences in flow between the graft types and between grafts with seromas versus no seromas. Five grafts were explanted and one was ligated, resulting in cannulation delays from 2 to 4 months. We conclude that the gelatin‐sealed PTFE vascular graft is not the ideal prosthesis for hemodialysis access.     

Penetrating Chest Injuries: Unusually High Incidence of High-velocity Gunshot Wounds in Civilian Practice

n = 190) followed by hemopneumothorax ( n = 184). Isolated thoracic injuries were found in 53% of the patients. Nonoperative management was sufficient in 92% of the patients. Thoracotomy was performed in 8.1%. The mean duration of hospitalization was 11.2 days. The mean injury severity score (ISS) was 20.17 ± 13.87. The morbidity was 23.3% and the mortality 5.6%. Fifty percent of all deaths were due to adult respiratory distress syndrome. Altogether 17% of patients with an ISS >25 died, whereas only 0.9% of those with a score <16 died. The mortality due to firearms was 8.95%. We concluded that in civilian practice chest tube thoracostomy remains by far the most common method of treating penetrating injury to the chest. The easy availability of high-velocity guns will continue to increase the number of civilians injured by these weapons.     

High Incidence of Tracheomalacia in Longstanding Goiters: Experience from an Endemic Goiter Region

Background Our institute caters to a large number of patients with large, longstanding multinodular goiters; tracheal deviation and resulting airway problems like tracheomalacia are relatively common. However, the literature is sparse on the criteria of early diagnosis and optimum management of tracheomalacia, which our study highlights. Methods This retrospective study analyzed 900 thyroidectomies carried out during 1990–2005 for which data from 28 patients treated for tracheomalacia after thyroidectomy were available for analysis. Criteria for making a diagnosis of tracheomalacia after thyroidectomy included one or more of the following: normal vocal cord mobility, absence of glottic or subglottic edema or hematoma, soft and floppy trachea on palpation, obstruction to spontaneous respiration on gradual withdrawal of the endotracheal tube. Results Mean duration of thyroid enlargement was 13.75 years. Only 7 patients had a history of stridor. Tracheostomy was performed in 26 patients, and 2 patients were put on prolonged intubation. Tracheostomy was performed in 18 patients on the operating table, and 8 in the recovery room. The mean weight of the gland was 442 g and histopathology revealed that 11 cases were benign goiter. The tracheostomy tube was removed after an average of 8.5 days. There were no cases of tracheal stenosis on long-term follow-up. Conclusions Patients with longstanding goiter, even when benign, are more prone to develop tracheomalacia. On the basis of our experience we strongly advocate tracheostomy intraoperatively if the trachea is soft and floppy and/or collapse of the trachea is observed following gradual withdrawal of the endotracheal tube.