The rate of wear of second-generation highly crosslinked polyethylene liners five years post-operatively does not increase if large femoral heads are used.

AIMS: The increased in vivo resistance to wear of highly crosslinked polyethylene (HXLPE) in total hip arthroplasty (THA) has led to an increased use of larger articulations which have been shown to reduce the incidence of early dislocation. To date, there are few reports of the wear of larger articulations using second generation HXLPE liners. Our prospective cohort study measured the bedding-in and early wear of large (36 mm and 40 mm diameter) articulations involving a second generation X3 HXLPE liner and compared our findings with previous clinical and in vitro studies of the same material. PATIENTS AND METHODS: The proximal penetration of the femoral head five years post-operatively was measured for 15 patients using radiostereometric analysis (RSA). RESULTS: The median proximal bedding-in within the first post-operative year was 0.022 mm (interquartile range (IQR) -0.050 to 0.091). The median proximal rate of wear between one and five years was -0.004 mm/year (IQR -0.021 to 0.022). The rates of proximal, medial, 2D or 3D wear between one and five years post-operatively of the X3 HXLPE liner did not increase with larger articulations compared with our previous study of 32 mm articulations. CONCLUSION: Although reassuring, the use of larger articulations requires continued monitoring to determine whether the low wear observed in the short-term continues to the mid- to long-term. Cite this article: Bone Joint J 2016;98-B:1604-10.

The Unispacer knee implant: early clinical results.

The Unispacer knee system is a cobalt-chrome self-centring tibial hemiarthroplasty device for use in the treatment of isolated medial compartment osteoarthritis of the knee. The indications for use are similar to those for high tibial osteotomy, but insertion does not require bone cuts or component fixation, and does not compromise future knee replacement surgery. A prospective study of a consecutive series of 18 patients treated with the Unispacer between June 2003 and August 2004 was carried out to determine the early clinical results of this device. The mean age of the patients was 49 years (40 to 57). A total of eight patients (44%) required revision within two years. In two patients revision to a larger spacer was required, and in six conversion to either a unicompartmental or total knee replacement was needed. At the most recent review 12 patients (66.7%) had a Unispacer remaining in situ. The mean modified visual analogue score for these patients at a mean follow-up of 19 months (12 to 26) was 3.0 (0 to 11.5). The mean pain level was 30% that of the mean pre-operative level of 10. The early clinical results using this device have been disappointing. This study demonstrates that use of the Unispacer in isolated medial compartment osteoarthritis is associated with a high rate of revision surgery and provides unpredictable relief of pain.

Effect of intra-articular infliximab on synovial membrane pathology in a patient with a seronegative spondyloarthropathy.

OBJECTIVE: To demonstrate the efficacy of intra-articular infliximab in a patient with a persistent monarthritis who had previously had two arthroscopic synovectomies with limited success, and to determine the effect of intra-articular infliximab on synovial membrane pathology METHOD: Arthroscopic synovial biopsy specimens were collected before and after treatment with intra-articular infliximab. The synovial tissue was stained for a range of inflammatory cell subsets, cell adhesion molecules and cytokines using immunohistochemical techniques and quantified using digital image analysis and a semiquantitative scoring method. RESULTS: Clinical improvement in the knee synovitis was seen after the first two intra-articular infliximab treatments, with a sustained clinical remission lasting for more than 12 months after the third treatment. Significant changes in cellular infiltration and expression of cytokines and cell adhesion molecules occurred as a result of treatment with intra-articular infliximab, with a reduction in some but not all cells in the inflammatory infiltrate, as well as a reduction in the expression of cell adhesion molecules (intercellular adhesion molecule-1 and vascular adhesion molecule-1) and production of cytokines (interleukin 1beta and tumour necrosis factor alpha). CONCLUSION: Intra-articular infliximab administration is a viable treatment for a persistent monarthritis resistant to other treatment options and can successfully modulate the inflammatory milieu within the synovial membrane.

Patellar resurfacing in total knee replacement: a ten-year randomised prospective trial.

A series of 100 consecutive osteoarthritic patients was randomised to undergo total knee replacement using a Miller-Galante II prosthesis, with or without a cemented polyethylene patellar component. Knee function was evaluated using the American Knee Society score, Western Ontario and McMaster University Osteoarthritis index, specific patellofemoral-related questions and radiographic evaluation until the fourth post-operative year, then via questionnaire until ten years post-operatively. A ten-point difference in the American Knee Society score between the two groups was considered a significant change in knee performance, with alpha and beta levels of 0.05. The mean age of the patients in the resurfaced group was 71 years (53 to 88) and in the non-resurfaced group was 73 years (54 to 86). After ten years 22 patients had died, seven were suffering from dementia, three declined further participation and ten were lost to follow-up. Two patients in the non-resurfaced group subsequently had their patellae resurfaced. In the resurfaced group one patient had an arthroscopic lateral release. There was no significant difference between the two treatment groups: both had a similar deterioration of scores with time, and no further patellofemoral complications were observed in either group. We are unable to recommend routine patellar resurfacing in osteoarthritic patients undergoing total knee replacement on the basis of our findings.

Arthrofibrosis following total knee replacement; does therapeutic warfarin make a difference?

Arthrofibrosis following total knee replacement (TKR) is a relatively common complication which results in a reduction in knee range of movement and patient dissatisfaction. A retrospective study examined the relationship between anticoagulation with therapeutic warfarin and rates of arthrofibrosis following TKR. Arthrofibrosis was defined as less than 80 degrees of knee flexion 6-8 weeks post-TKR. Patients were warfarinised if they had a history of thrombophilic tendencies or medical conditions necessitating anti-coagulation, rather than as routine thromboprophylaxis. All other patients received thromboprophylaxis using low molecular weight heparin. A total of 728 patients underwent 874 primary TKR between 1993 and 2002 in one centre, performed by four surgeons. Mean age was 68 years (range 48-89 years) and there were 483 female and 391 male knees. Eighty cases were warfarinised post-operatively (53 female, 27 male). Overall, 83 of 874 TKRs (9%) had arthrofibrosis (57 female, 26 male) requiring manipulation under anaesthetic (MUA). In the warfarinised group, 21 knees (26%) had an MUA (15 female, 6 male). This compared to 62 cases (8%) requiring MUA in the non-warfarinised group (42 female, 20 male). There was a statistically significant difference on Fisher's exact testing (P<0.0001) between groups. Following MUA, knee flexion improved in 95% cases to a minimum 95 degrees but 8 cases had a fixed flexion deformity of 5-10 degrees . In conclusion, therapeutic warfarinisation post-TKR leads to a statistically greater chance of the patient developing arthrofibrosis compared to prophylactic low molecular weight heparin and that patients should be counseled appropriately.

Patient-perceived outcome measures following unicompartmental knee arthroplasty with mini-incision.

We reviewed 150 patients (183 knees) who underwent mini-incision unicompartmental knee arthroplasty (Oxford). Mean age was 71.5 (36-92) years. Review was conducted at least 12 months following surgery. To assess results, we used the Oxford knee questionnaire, modified Grimby score, return to sport and work, knee "normality" and patient general health. The mean Oxford knee score was 22.17 (range 12-54). Kneeling scored worse than other activities. No significant age or gender difference was found. Mean modified Grimby score was 3.89, equating to moderate exercise less than 2 h a week. Patients with "artificial-feeling" knees had significantly worse scores than patients with normal/near-normal-feeling knees. Patients who returned to/increased sporting activity had better Oxford scores than those who did not. Ninety-four percent of patients working pre-operatively returned to work. Sixty-seven percent continued at the same level of or increased sporting activity. Oxford knee scores and return to sport compared well to published data. Results regarding modified Grimby score, return to work and pain relief were encouraging. The best results were achieved in active patients who felt their health was good and their knee felt normal or near normal following surgery.

Sociotropy and autonomy: preliminary evidence for construct validity using TAT narratives.

In this investigation, we evaluated the construct validity of sociotropy and autonomy as assessed by the revised Personal Style Inventory (PSI; Robins et al., 1994). Stories given to 6 cards of the Thematic Apperception Test (Murray, 1943) were coded for need for Achievement (McClelland, Atkinson, Clark, & Lowell, 1953) and need for Affiliation (Heyns, Veroff, & Atkinson, 1958). These scores were correlated with PSI Sociotropy and Autonomy, along with their component subscales. The construct validity of Sociotropy, Autonomy, and 5 of 6 component subscales were supported as hypoth sized. Consistent with past research, there was no support for the construct validity of the Perfectionism/Self-Criticism subscale of Autonomy. In addition, separate analyses by gender suggested that the construct validity of sociotropy may be greater for women than for men. The results represent an important finding in that nonquestionnaire measures of interpersonal and achievement-related concerns were found to support the validity of the PSI, a need identified by the questionnaire's authors.

Technique for arthroscopic assisted revision hip arthroplasty.

We describe a new technique in which the arthroscope is used to assist the preparation of the cement mantle for cemented revision hip arthroplasty. We present two case reports demonstrating the method and its rationale.

Reliability of acetabular bone defect classification systems in revision total hip arthroplasty.

Three classifications for assessment of acetabular bone loss were evaluated for their reliability. The 3 systems assessed were the system described by Gross, the system described by Paprosky, and the classification of the American Academy of Orthopaedic Surgeons. In this study, we assessed their reliability based on the preoperative radiographs alone. Intraobserver agreement was measured by evaluating the classifications by the 3 innovators, 3 reconstructive orthopaedic surgeons, and 3 residents. Interobserver agreement was assessed among the reconstructive surgeons and the residents. The unweighted kappa statistic was used to establish levels of agreement. The innovators had better intraobserver agreement than the other 2 groups. Their agreement was only in the moderate range, however. For the noninnovators, intraobserver and interobserver agreement generally was poor for all 3 classifications assessed. Our results indicate that these classifications do not provide statistically reliable information for preoperative assessment of acetabular bone stock loss.

Posterior capsule rupture after a paint-pellet injury.

We report a case in which a high-velocity paint pellet injury to the eye ruptured the posterior lens capsule. In the setting of blunt trauma, posterior capsule rupture has rarely been reported. Recognizing such a rupture allows the surgeon to plan the best surgical approach.

Sterilization of HIV with irradiation: relevance to infected bone allografts.

BACKGROUND: Bone allograft banks commonly sterilize frozen bone by irradiation. The dose-response relationship for HIV is calculated and the dose required to inactivate the bioburden of virus that may be present in allograft bone is determined. METHODS: A virus titre experiment is performed using irradiated frozen HIV. The virus is maintained on dry ice (approximately -70 degrees C) and is exposed to a cobalt 60 source with 0-40 kGy irradiation at 5 kGy intervals. Lymphocyte cell cultures are exposed to serial dilutions of the irradiated virus. The virus titre is quantified by cytological changes of HIV infection and p24 immunofluorescence. RESULTS: There is a linear relationship between the virus titre and the radiation dose delivered. The inactivation rate of irradiated virus was 0.1134 log10 tissue culture infective doses 50/mL per kGy (95% confidence intervals, 0.1248-0.1020). The irradiation dose required to inactivate the HIV bioburden in allograft bone is 35 kGy. The irradiation dose required to achieve a sterility assurance level of 10(-6) is 89 kGy. This dose exceeds current recommendations for sterilizing medical products and the current practice of many bone banks. CONCLUSIONS: It is concluded that gamma irradiation should be disregarded as a significant virus inactivation method for bone allografts.

The Environmental Rating Scale (ERS): a measure of the quality of the residential environment for adults with autism.

This study used classical test theory to assess the psychometric properties of the Environmental Rating Scale (ERS), a measure specifically designed to assess the treatment programs in residential settings that serve individuals with autism. Results of the confirmatory factor analysis support the presence of a single factor represented by the total score. The reliability of the measure was demonstrated by assessments of the internal consistency, stability, and interrater reliability. Preliminary analysis of the validity of the ERS indicates that this measure discriminates between treatment settings designed specifically for individuals with autism and those designed for other populations of developmentally handicapped clients and family homes. The ERS was also significantly positively correlated with a measure of the caregiver's knowledge about autism and a visitor's global impression of the desirability of the setting as a place to live.

Seven specialized exposures for revision hip and knee replacement.

With the increasing rates and complexity of revision hip and knee arthroplasty, it has become more important than ever to approach the joint in a safe and rational manner. The development of extensile approaches have significantly simplified the removal of solidly fixed components without compromising bone stock. The extended trochanteric osteotomy enables controlled access to the femoral component and is a useful technique for revision of solidly-fixed femoral components. The trochanteric slide allows comprehensive exposure of the acetabulum and femur comparable to trochanteric osteotomy with a diminished risk of trochanteric escape. The vastus slide allows wide exposure of the femoral shaft when using an anterolateral approach. In revision total knee arthroplasty, the extensor mechanism is often at risk of disruption or avulsion, and in most cases, maneuvers that allow wide exposure of the femur and tibia while preserving the extensor mechanism are essential. Such exposures include one of the extensor mechanism reflecting techniques either proximally by rectus snip or patellar turndown, or distally by tibial tubercle osteotomy. Occasionally a femoral peel or epicondylar osteotomy is required. There should be a low threshold to consider one of these specialized approaches during revision hip and knee arthroplasty.

Ocular bubble formation as a method of assessing decompression stress.

Tear film bubble formation and ultrasound reflectivity of the lens-vitreous humor compartments were monitored following simulated dives in a hyperbaric chamber. the sensitivity of these methods in determining decompression stress was compared with the results of precordial Doppler ultrasound. In addition, the utility of these diagnostic techniques in testing decompression dive profiles was evaluated. Eleven divers completed two series of chamber dives according to the decompression schedule of the Professional Association of Diving Instructors. The first dive series comprised dives to 70 feet of seawater (fsw) for 15, 29, and 40 min. The second series comprised maximum duration no-stop decompression dives to 40 fsw for 140 min, 70 fsw for 40 min, 90 fsw for 25 min, and 120 fsw for 13 min. Before and immediately after each dive, the following measurements were obtained from each subject: eye surface tear film bubble counts with a slit-lamp microscope, lens and vitreous humor reflectivity using A- and B-mode ophthalmic ultrasonic scan, and precordial Doppler ultrasonic detection of venous gas bubbles. Tear film bubble assessment and ocular scanning ultrasound were observed to be more sensitive in detecting decompression stress than the conventional Doppler ultrasonic surveillance of the precordial region. In contrast to precordial Doppler ultrasonic surveillance, which failed to detect any significant changes in circulating bubbles, tear film bubble formation displayed a dose-response relationship with increasing duration of the 70-fsw dives. Reflectivity changes of the lens-vitreous humor interface were not significant until the no-stop decompression limit was reached. In addition, for each of the no-stop decompression limit dives, increases in the average tear film bubble formation and lens-vitreous humor interface reflectivity were similar. Ocular bubble observations may provide a practical and objective ocular bubble index for analyzing existing decompression schedules and predicting individual susceptibility to decompression sickness.

Delayed hyphema and intravitreal blood following intrableb autologous blood injection after trabeculectomy.

PURPOSE: To report delayed hyphema and intravitreal blood as complications following intrableb autologous blood injection after trabeculectomy. METHODS: Case report. A 44-year-old woman with hypotony and maculopathy after trabeculectomy with mitomycin C received an intrableb autologous blood injection. RESULTS: Three days after the blood injection, a hyphema formed and subsequently dispersed into the vitreous. CONCLUSIONS: Although immediate hyphema from autologous blood injection is common, hyphema may be delayed and associated with intravitreal blood.

The autism survey: an evaluation of reliability and validity.

Psychometric properties of the Autism Survey, an instrument designed to assess respondents' knowledge about autism, were evaluated. Subjects completed the survey at a training conference and again 1 month later. Confirmatory factor analysis indicated that the survey measures one factor. With respect to reliability, the Autism Survey proved to be stable across time, and the total score was internally consistent. A few rogue items were recommended for deletion. Further analyses support the validity of the instrument.

Human immunodeficiency virus infection of human bone derived cells.

Human immunodeficiency virus infection of a human bone derived cell line was initiated by either cell free virus or with a cell to cell transmission method. The human bone derived cells were examined for 8 weeks, and virus infection was not detected when assessed by microscopy, immunofluorescence, reverse transcriptase activity, or infection of cocultivated human T lymphoid cells susceptible to human immunodeficiency virus. Polymerase chain reaction analysis of human bone derived cells inoculated with the cell to cell infection format showed less than 0.1% infected cells. It is possible that the infected cells detected by polymerase chain reaction were lymphocytes used in the cell to cell infection format. Alternatively, latent infection may have been established in the bone derived cells with no apparent expression of the proviral genome. A large proportion of bone is represented by human bone derived cells, and it is unlikely that bone will contribute to a significant human immunodeficiency virus reservoir in vivo. The blood of bone allograft donors is likely to have a greater virus bioburden than is bone. Methods to sterilize bone should be assessed by their efficacy to inactivate the virus in blood contaminating the graft, and methods to detect human immunodeficiency virus deoxyribonucleic acid in a bone graft may be less sensitive than examining the donor's blood.