Ongoing MRI remodeling 3-7 years after collagen meniscus implantation in stable knees

PURPOSE

The purpose of the present study was to evaluate the clinical and radiological 3-7 years outcomes of patients who underwent collagen meniscus implantation in stable or stabilized knees. It was the hypothesis that using the collagen meniscus (CMI) good clinical 3-7 years outcomes with low pain levels are achieved.

METHODS

Thirty-nine patients (male:female = 30:9, mean age 34 ± 10 years) underwent arthroscopic CMI after subtotal medial (n = 32) or lateral meniscectomy (n = 7). A 7-mm CMI was performed due to prophylactic (n = 25) or therapeutic indication (n = 14). IKDC score, Tegner score preinjury, preoperatively and at follow-up, Lysholm score and visual analogue scale for pain and satisfaction (follow-up rate 90%) were assessed. MRI scans were analyzed according to the Genovese criteria (n = 19). Implant failure was defined as infection or mechanical failure of the device. The minimum follow-up time was 36 months (range 36-84 months).

RESULTS

The mean VAS satisfaction preoperatively and at follow-up was 4.0 ± 0 and 1.6 ± 1.0. The mean VAS pain was 4.3 ± 3.2 preoperatively and at last follow-up 2.1 ± 1.7. The median Tegner score preinjury was 7 (range 3-10), it decreased preoperatively to median 3.5 (range 1-8) and nearly reached the preinjury level at last follow-up 6 (range 3-10). The mean Lysholm score before surgery was 66 ± 20 and 91 ± 8 at last follow-up. Seven patients (38.9%) had a normal total IKDC score (A), 10 patients were nearly normal (B) and 1 patient slightly abnormal (C). In MRI the CMI was entirely resorbed in 4 patients (21%) and partially resorbed in 15 (79%). In 4 patients (21%) the CMI was isointense, in 14 (74%) slightly hyperintense and in 1 (5%) highly hyperintense. Ten patients (53%) showed marked signs of bone marrow edema. In 13 patients (68%) an extrusion of the meniscus > 3 mm at last follow-up was found.

CONCLUSIONS

Meniscal substitution with the CMI showed good to excellent clinical 3-7 results. The CMI shows an ongoing remodelling with decreased signal intensity and decreased size. However, as meniscus extrusion remained at the same level and bone marrow edema decreased from 1 year to longer term follow-up, it appears that the remodeling comes to an end at about 5 years after CMI.

LEVEL OF EVIDENCE

IV.

What is the effect of self-identified HIV activism in willingness to participate in HIV cure-related clinical trials? Results from the ANRS-APSEC study

OBJECTIVES

Enrolling people living with HIV with undetectable viral load into HIV cure-related clinical trials (HCRCT) is challenging. Few data are currently available about the individual factors that influence willingness to participate in HCRCT (WPHCRCT). We hypothesised that WPHCRCT would be more frequent among people living with HIV considering themselves HIV activists. The objective of this study was to investigate the individual characteristics associated with both WPHCRCT and self-identification as an HIV activist.

METHODS

The study enrolled 195 long-term ART-treated and virologically suppressed people living with HIV, followed-up in 19 French HIV services, 2016-2017. A Bayesian model averaging approach was used to assess correlates of both outcomes i.e. WPHCRCT and self-identified HIV activism.

RESULTS

WPHCRCT was reported by 43% of participants and was positively associated with self-identification as an HIV activist (adjusted odds ratio [aOR] 2.90 95% confidence interval [CI] 2.17-3.63], P<0.05) and self-confidence as an HIV positive person (aOR 1.17, 95% CI 0.99-1.35, P<0.1). Self-identified HIV activists (56% of participants) were more likely to have a higher 'relationship with others' score using the post-traumatic growth inventory (aOR 1.10, 95% CI 0.99-1.20, P<0.1), to obtain information about HIV from a greater number of sources (aOR 1.35 [95% CI 1.00-1.68], P<0.1), and to feel greatly affected by mandatory daily treatment (aOR 2.15, 95% CI 1.27-3.03, P<0.1). All associations had relative importance weight>0.75, indicating strong evidence.

CONCLUSIONS

WPHCRCT is strongly related to HIV activism, and also to positive psychosocial characteristics as a person living with HIV, especially regarding relationships with others. The desire to contribute to the fight against HIV for the sake of the HIV community and society should be taken into account to improve participation in upcoming HCRCT.

Recruitment and ethical considerations in HIV cure trials requiring treatment interruption

INTRODUCTION

Relative to antiretroviral treatment (ART), early HIV cure-related trials (HCRTs) carry limited therapeutic benefits and unknown risks. In HCRTs requiring treatment interruption (TI) the health risks and burdens may create a barrier to study enrolment and increase the possibility for unintentional ethical violations in recruitment.

METHODS

An online survey was administered to over 2,000 HIV-positive ART users in the US. Using multivariable ordinal regression we assessed effects of research participation attitudes, health and demographic traits on willingness to participate in treatment interruption studies (WtP-TI).

RESULTS

WtP-TI was greatest among those who were highly motivated to participate in research studies for the benefit of science, society and, to a lesser extent, personal benefit. Personal benefit was less of an influence on WtP-TI among persons with higher viral loads or a history of multiple ART regimens. WtP-TI was greater among respondents who were more likely to consider personal health in making decisions about trial participation. WtP-TI had no association with perceptions of the importance of compensation to research participation. After accounting for attitudes, health status and demographic traits were generally not significantly related to WtP-TI. Notable exceptions included viral suppression status and race/ethnicity.

CONCLUSION

Recruitment strategies in TI studies can benefit from a focus on the long-term scientific and social benefits of study participation. Strategies targeted to particular demographic groups may have little impact on accrual, and in some cases will need to be accompanied by strategies to improve the quality of researcher-community relationships. Findings also suggest that informing communities about the health impacts of trial participation may positively impact participation decisions. However, more research is needed to interpret the impact of health messaging on recruitment and therapeutic expectations. Future work should explore the implications of altruism-based expectations on the strategic and ethical appropriateness of TI study recruitment efforts.

Sources of racial/ethnic differences in awareness of HIV vaccine trials

OBJECTIVES

We explored the relative effects of 2 awareness components-exposure and attention-on racial/ethnic differences in HIV vaccine trial awareness among men who have sex with men (MSM).

METHODS

Surveys assessing awareness of and attitudes toward HIV vaccine trials were administered to 1723 MSM in 6 US cities. Proxy measures of exposure included use of HIV resources and other health care services, community involvement, income, and residence. Attention proxy measures included research attitudes, HIV susceptibility, and HIV message fatigue. Using logistic regression models, we assessed the extent to which these proxies accounted for racial/ethnic differences in vaccine trial awareness.

RESULTS

White MSM reported significantly (P < .01) higher rates of HIV vaccine trial awareness (22%) compared with Latino (17%), Black (13%) and "other" (13%) MSM. Venue-based exposure proxies and research-directed attitudinal attention proxies were significantly associated with awareness, but only accounted for the White-Latino disparity in awareness. No proxies accounted for the White-Black or White-"other" differentials in awareness.

CONCLUSIONS

Sources of disparities in awareness of HIV vaccine trials remain to be explained. Future trials seeking to promote diverse participation should explore additional exposure and attention mediators.

One-year clinical and MR imaging outcome after partial meniscal replacement in stabilized knees using a collagen meniscus implant

PURPOSE

The purpose of the study was to evaluate the clinical and radiological outcomes after medial/lateral collagen meniscus substitution (CMI) at 12 months postoperatively.

METHODS

Sixty-seven patients (m:f = 47:20, mean age 36 ± 10 years) underwent arthroscopic CMI after previous subtotal medial (n = 55) or lateral meniscectomy (n = 12) due to persistent joint line pain (n = 25) or to prophylactic reasons (n = 42). Clinical follow-up consisted of IKDC score, Tegner score, Lysholm score, and visual analog scale for pain and satisfaction (preinjury, preoperatively, and 12 months postoperatively; follow-up rate 90 %). MRI scans were analyzed according to the Genovese criteria.

RESULTS

Nineteen patients (29 %) showed a normal (A), 35 nearly normal (B), 5 abnormal (C), and 1 patient severely abnormal total IKDC score (D). The median Tegner preinjury score was 7 (range 2-10) and at follow-up 6 (range 2-10). The mean Lysholm score before surgery was 68 ± 20 and 93 ± 9 at follow-up. Preoperatively, the mean VAS pain was 4.4 ± 3.1 and 2.0 ± 1.0 at follow-up. Clinical failure of the CMI occurred in 3 patients (n = 1 infection, n = 1 failure of the implant, n = 1 chronic synovitis). On MRI, the CMI was completely resorbed in 3 patients (5 %), partially resorbed in 55 (92 %), and entirely preserved in 3 (5 %) patients. In 5 patients (8 %) the CMI was isointense, in 54 (90 %) slightly and 1 (2 %) highly hyperintense. 43 (72 %) patients showed an extrusion of the CMI implant of more than 3 mm.

CONCLUSIONS

Significant pain relief and functional improvement throughout all scores at 1 year was noted. The CMI undergoes significant remodeling, degradation, resorption, and extrusion in most of the patients. No difference in outcomes between the medial and lateral CMI was observed.

LEVEL OF EVIDENCE

Prospective therapeutic study, Level IV.

Socioeconomic position and HIV risk-relevant behavior among lower-income heterosexuals in San Francisco

We assess whether there is evidence of an association between socioeconomic position (SEP) and HIV risk-relevant behavior among lower income heterosexual men and women in San Francisco. Respondents residing in low income areas with high heterosexual AIDS case burden in San Francisco were recruited through long-chain referral in 2006–2007. Risk measures included unprotected vaginal intercourse, concurrency and exchange sex. SEP was defined as household annual income, per capita income, and employment. Analyses utilized mixed and fixed effects models. A total of 164 men and 286 women were included in the study. SEP was only significant in the case of exchange sex among men: men reporting annual income greater than $30,000 had significantly lower odds of exchange sex relative to other men. Evaluating the connection between economic status and HIV requires additional studies covering diverse populations. Future studies should focus on community economic context as well as individual SEP.

Abnormal landing strategies after ACL reconstruction

The objective was to analyze muscle activity and movement patterns during landing of a single leg hop for distance after anterior cruciate ligament (ACL) reconstruction. Nine (six males, three females) ACL-reconstructed patients 6 months after surgery and 11 (eight males, three females) healthy control subjects performed the hop task. Electromyographic signals from lower limb muscles were analyzed to determine onset time before landing. Biomechanical data were collected using an Optotrak Motion Analysis System and force plate. Matlab was used to calculate kinetics and joint kinematics. Side-to-side differences in ACL-reconstructed patients and healthy subjects as well as differences between the patients and control group were analyzed. In ACL-reconstructed limbs, significantly earlier onset times were found for all muscles, except vastus medialis, compared with the uninvolved side. The involved limbs had significantly reduced knee flexion during the take-off and increased plantarflexion at initial contact. The knee extension moment was significantly lower in the involved limb. In the control group, significantly earlier onset times were found for the semitendinosus, vastus lateralis and medial gastrocnemius of the non-dominant side compared with the dominant side. Muscle onset times are earlier and movement patterns are altered in the involved limb 6 months after ACL reconstruction.

[Mountain biking. Cool way to enjoy nature with side effects]

Mountain biking grew from a trend to a serious branch of sport. This article presents the different subspecialties within the sport, the injury rates and the types of injuries among high-class and recreational bikers. The experiences made during several years as a team physician of top athletes as well as the statistics from the Swiss accident insurance company SUVA are the basis for the data presented. The issue of mountain bike-related concussions is particularly discussed since this type of injury is a point of increasing concern in the recent sports traumatology literature.

Twist and its effect on ACL graft forces

Graft tension is a controversial topic in anterior cruciate ligament (ACL) surgery. Evidence suggests a narrow range of graft tensions, which allow the graft to remodel to a stable and mature neoligament. In previous cadaver experiments, we showed that twisting the graft could modulate the graft forces. In this study we hypothesized that the same phenomena would be found in patients, and that twisting the graft intraoperatively can reduce peak forces in the graft. The effects of twist on graft forces in bone-patellar tendon-bone grafts were measured during anterior cruciate ligament surgery on 15 consecutive patients using a custom-made tension-measurement device. Variations in surgical procedure that could potentially affect the graft force patterns were quantified. Graft force as a function of knee-flexion angle was measured with the graft in the neutral, untwisted position and repeated with the tibial bone block rotated externally or internally by 180 degrees. In eight of the 15 knees, external twisting of the graft reduced the maximal graft force to 50%. However, in five knees the forces in extension increased by twisting to a maximum of 300%. Of the surgical variables, only the femoral tunnel position appeared to have a consistent effect on the graft force pattern. Due to the unpredictable effect of graft twisting, a general recommendation on whether the graft should be twisted, and if so, in which direction, cannot be given. Intraoperatively, graft twisting may however be considered in every individual knee to modulate the graft force as a function of flexion angle.

Single-incision technique misses the anatomical femoral anterior cruciate ligament insertion: a cadaver study

We examined the arthroscopic appearance of the anterior cruciate ligament (ACL) attachment site on the femur in five fresh-frozen cadaver knees. First, the ACL was cut out, leaving a footprint of ligament-fibers with a length of 2 mm intact. The ACL was consistently found to insert on the lateral wall of the notch. No fibers were found to attach high in the roof of the notch at the 12 o'clock position. Secondly, we tried to reach the anatomical attachment site with a femoral aiming guide through a correctly placed tibial tunnel. This proved to be impossible. The closest position that could be reached was at the margin of the anatomical attachment site. Investigation of the distal femur after complete dissection confirmed these arthroscopic findings. Femoral aiming devices for use through the tibial tunnel aim for an isometric placement of the femoral tunnel, they do not aim for an anatomical position of the graft.

Symptomatic ring-shaped lateral meniscus

Abnormalities of the lateral meniscus in humans are a long-known fact. Three different types of discoid menisci are described in Watanabe's atlas, being considered as congenital malformations. For the second time in the literature, a fourth ring-shaped type of discoid lateral meniscus was described as an incidental finding in this Journal by Monllau et al. in 1998. The present case is the first description of a symptomatic, ring-shaped lateral meniscus with a concomitant, recurrent cyst at the lateral aspect of a child's knee.

[Patellar substitution in total knee prosthesis--is it important?]

As shown in long term follow-up studies of Total Knee Arthroplasty (TKA), the femoropatellar joint is an important problem. We report our experience over the past seven years not having resurfaced the patella at the primary TKA at all. Between 1990 and 1997 more than 700 consecutive TKA with the De Puy New Jersey LCS prosthesis were performed. A standardised lateral approach with osteotomy of the tibial tuberosity was used. The patella was redressed, either denervated or left untouched. In no case a primary patellar resurfacing was performed. X-rays of the patello-femoral joint showed a remodelling of the patella over the years, nicely matching the condylar design of the femoral prosthesis. Using a blood-supply-preserving approach and a biomechanically adequate implant, TKA without patellar replacement gives excellent long-term results.

Short-term in vivo stability of endothelial-lined polyester elastomer and polytetrafluoroethylene grafts

A fibronectin substrate will significantly enhance the strength of endothelial cell attachment on grafts constructed of polyester elastomer (PE) and polytetrafluoroethylene (e-PTFE). This experiment was undertaken to determine the short-term in vivo stability of endothelium on these fibronectin coated surfaces. Eight mongrel dogs underwent bilateral carotid artery replacement with both graft materials. All grafts were inoculated with 2,000 cells/mm2 using cultured autogenous venous endothelium labelled with Indium-111-oxine. The Indium-111 label in the grafts was measured immediately prior to implantation, after 1 hour of in vivo perfusion, and at explantation after 24 hours. The percentage of inoculated cells attached to the grafts before perfusion was similar for both materials, 93.3 +/- 3.0% versus 92.2 +/- 7.2%, for PE and e-PTFE respectively. All grafts were patent at one hour after implantation. PE grafts were found to have 93.8 +/- 3.9% of the attached cells present at one hour while e-PTFE grafts had only 54.5 +/- 10.8% remaining, p less than .001. After 24 hours, 5/8 (62.5%) e-PTFE grafts and 2/8 (25.0%) PE grafts remained patent, p = .13. Of the patent grafts however, endothelial cell retention was still superior on the PE grafts with 78.0 +/- 0.6% of the attached cells remaining compared to only 24.5 +/- 6.1% on e-PTFE, p less than .001. Occluded PE grafts had fewer cells remaining at 24 hours than patent ones, 78.0 +/- 0.6% versus 31.1 +/- 32.8%, respectively, p = .13. Histologically, patent PE grafts demonstrated nearly confluent endothelial monolayers while e-PTFE had patches of endothelial cells surrounded by a platelet-fibrin carpet.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced strength of endothelial attachment on polyester elastomer and polytetrafluoroethylene graft surfaces with fibronectin substrate

Successful development of a vascular prosthesis lined with endothelium may depend on the ability of the attached cells to resist shear forces after implantation. The purpose of this article is to describe a model for measurement of endothelial detachment caused by shear stress and to identify biomaterials that resist loss of attached cells as a result of shear stress. With human umbilical venous endothelium labeled with indium 111-oxine, cellular attachment to uncoated and fibronectin-coated polyester elastomer and expanded polytetrafluoroethylene (e-PTFE) graft surfaces was quantified after an 18-hour incubation. PTFE grafts prepared by immediate seeding were also studied. The relative strength of endothelial attachment was determined by the percentage of the original inoculum remaining after the seeded graft surfaces were subjected to a physiologic shear stress of 15 dynes/cm2 during in vitro perfusion. In polyester elastomer grafts, fibronectin did not significantly increase initial attachment but did increase the percentage of inoculum remaining after perfusion (92.1% vs. 39.74%, p = 0.001). A similar relationship existed between fibronectin-coated e-PTFE and immediately seeded e-PTFE preparations with 61.6% and 25.8%, respectively, of the inoculum remaining after perfusion (p = 0.001). Furthermore, the percentage of inoculum retained on fibronectin-coated polyester elastomer was significantly greater than on fibronectin-coated e-PTFE (p = 0.001). In comparing uncoated grafts, polyester elastomer had 39.7% of the inoculum retained after perfusion whereas only 1.8% was remaining on the e-PTFE grafts (p = 0.0001). We conclude that polyester elastomer permits better endothelial cell attachment than e-PTFE and that fibronectin coating enhances the strength of attachment to both graft materials.