Background
Bone-patellar tendon-bone (bone-tendon-bone) and four-strand hamstring tendon grafts (hamstring) are the most commonly utilized autografts for primary anterior cruciate ligament (ACL) ...reconstruction. Existing clinical trials, registry studies, and meta-analyses offer conflicting opinions regarding the most favorable graft choice.
Questions/purposes
Which graft type for ACL reconstruction (bone-tendon-bone or hamstring) has a higher risk of (1) graft rupture and/or (2) graft laxity?
Methods
We performed a meta-analysis of randomized controlled trials (RCTs), prospective cohort studies, and high-quality national registry studies to compare the outcomes of primary ACL reconstruction with bone-tendon-bone autograft or hamstring autograft. Studies that compared these graft types were identified through a comprehensive search of electronic databases (PubMed, MEDLINE, EMBASE, and the Cochrane Library). Two independent reviewers utilized the Jadad scale for RCT study quality and the Modified Coleman Methodology Score for prospective comparative and registry study quality. The included studies were analyzed for the primary outcome measure of graft rupture with or without revision ACL surgery. In surviving grafts, secondary outcomes of graft laxity were quantified by KT1000/2000™ testing, a positive pivot shift test, and a positive Lachman test. Meta-analysis was performed with Review Manager. A total of 47,613 ACL reconstructions (39,768 bone-tendon-bone and 7845 hamstring) from 14 RCTs, 10 prospective comparative studies, and one high-quality national registry study were included in this meta-analysis. Mean age was 28 years in both groups. Sixty-three percent of patients in the bone-tendon-bone cohort were men versus 57% of patients in the hamstring cohort. Mean followup was 68 ± 55 months.
Results
Two hundred twelve of 7560 (2.80%) bone-tendon-bone grafts ruptured compared with 1123 of 39,510 (2.84%) in the hamstring group (odds ratio = 0.83, 95% confidence interval, 0.72-0.96; p = 0.01). The number needed to treat analysis found that 235 patients would need to be treated with a bone-tendon-bone graft over a hamstring tendon graft to prevent one graft rupture. Instrumented laxity analysis showed that 22% (318 of 1433) of patients in the bone-tendon-bone group had laxity compared with 18% (869 of 4783) in the hamstring tendon group (odds ratio = 0.86; p = 0.16). Pivot shift analysis showed a positive pivot shift in 19% (291 of 1508) of the bone-tendon-bone group compared with 17% (844 of 5062) in the hamstring group (odds ratio = 0.89; p = 0.51). Lachman testing showed a positive Lachman in 25% (71 of 280) of patients receiving bone-tendon-bone grafts compared with 25% (73 of 288) in the hamstring group (odds ratio = 0.96; p = 0.84).
Conclusions
In this meta-analysis of short- to mid-term followup after primary ACL reconstruction, hamstring autografts failed at a higher rate than bone-tendon-bone autografts. However, failure rates were low in each group, the difference observed was small, and we observed few differences between graft types in terms of laxity. Both graft types remain viable options for primary ACL reconstruction, and the difference in failure rate should be one part of a larger conversation with each individual patient about graft selection that should also include potential differences in donor site morbidity, complication rates, and patient-reported outcome measures. Continued prospective collection of patient data will be important going forward as we attempt to further characterize the potential differences in outcomes attributable to graft selection.
Level of Evidence
Level III, therapeutic study.
Purpose
Optimal surgical treatment of chondral defects in an athletic population remains highly controversial and has yet to be determined. The purpose of this review was to (1) report data on return ...to sport and (2) compare activity and functional outcome measures following various cartilage restoration techniques.
Methods
A comprehensive review was performed for studies with return-to-sport outcomes after microfracture (MFX), osteochondral autograft transfer (OAT), osteochondral allograft transplantation (OCA), and autologous chondrocyte implantation (ACI). All studies containing return-to-sport participation with minimum 2-year post-operative activity-based outcomes were included. A meta-analysis comparing rate of return to sport between each surgical intervention was conducted using a random-effects model.
Results
Forty-four studies met inclusion criteria (18 Level I/II, 26 Level III/IV). In total, 2549 patients were included (1756 M, 793 F) with an average age of 35 years and follow-up of 47 months. Return to sport at some level was 76 % overall, with highest rates of return after OAT (93 %), followed by OCA (88 %), ACI (82 %), and MFX (58 %). Osteochondral autograft transfer showed the fastest return to sports (5.2 ± 1.8 months) compared to 9.1 ± 2.2 months for MFX, 9.6 ± 3.0 months for OCA and 11.8 ± 3.8 months for ACI (
P
< 0.001). A meta-regression was conducted due to heterogeneity in preoperative factors such as patient age, lesion size, and preoperative Tegner score. None of these factors were found to be significant determinants for rate of return to sport.
Conclusion
In conclusion, in this meta-analysis of 2549 athletes, cartilage restoration surgery had a 76 % return to sport at mid-term follow-up. Osteochondral autograft transfer offered a faster recovery and appeared to have a higher rate of return to preinjury athletics, but heterogeneity in lesion size, athlete age, and concomitant surgical procedures are important factors to consider when assessing individual athletes. This study reports on the rate of return to sport in athletes undergoing various procedures for symptomatic chondral defects.
Level of evidence
IV.
CNTs grown on stainless steel mesh can dewater water–oil emulsion with 80% efficiency by blocking water droplets larger than the mesh opening due to superhydrophobicity of CNTs. Oil can penetrate ...through the mesh due to oleophilicity of CNTs. Some small water droplets can also leak through the mesh.
Display omitted
► Carbon nanotubes grown on stainless steel mesh forms three-dimensional porous structures (SS-CNT meshes). ► The superhydrophobic SS-CNT meshes can dewater water–oil emulsion with 80% efficiency by blocking large water droplet. ► The superoleophilic SS-CNT meshes allow oil to leak through.
Vertically-aligned multi-walled carbon nanotubes (CNTs) were grown on stainless steel (SS) mesh by thermal chemical vapor deposition with a diffusion barrier of Al
2O
3 film. These three-dimensional porous structures (SS-CNT meshes) were found to be superhydrophobic and superoleophilic. Water advancing contact angles of 145–150° were determined for these SS-CNT meshes in air and oil (gasoline, isooctane). Oil, on the other hand, completely wet the SS-CNT meshes. This combined superhydrophobic and superoleophilic property repelled water while allowed the permeation of oil. Filtration tests demonstrated efficiencies better than 80% of these SS-CNT meshes as the filtration membranes of the water-in-oil emulsions. We have conducted quantitative analysis on the diameters of the oil droplets in both the feed emulsion and the filtrate. Then, we have evaluated the issue of water blockage and possible way to improve the filtration efficiency. Finally, the filtration and blockage mechanisms are proposed.
Purpose
Medial meniscus posterior root tears (MMPRTs) are a significant source of pain and dysfunction, but little is known about the natural history and outcome and for non-operative management of ...these lesions. The purpose of this study was to evaluate (1) the mid-term clinical and radiographic outcomes of non-operative treatment of MMPRTs and (2) risk factors for worse outcomes.
Methods
A retrospective review was performed for patients with symptomatic, unrepaired MMPRTs and a minimum 2-year follow-up for IKDC and Tegner outcome scores. Baseline and final radiographs were reviewed and graded according to Kellgren–Lawrence scores. Baseline MRIs were reviewed for the presence of meniscal extrusion, subchondral oedema, and insufficiency fractures. Failure was defined as conversion to arthroplasty or severely abnormal patient subjective IKDC score.
Results
Fifty-two patients (21M:31F) with a mean age of 58 ± 10 years were diagnosed with symptomatic MMPRTs clinically and confirmed by MRI and followed for a mean of 62 ± 30 months. Sixteen patients (31 %) underwent total knee arthroplasty at a mean of 30 ± 32 months after diagnosis with higher Kellgren–Lawrence grades associated with increased rates of arthroplasty (
p
= 0.01). Mean IKDC scores for the remaining patients were 61.2 ± 21 with significantly lower scores in females compared to males (75 ± 12 vs. 49 ± 20;
p
= 0.03). Mean Kellgren–Lawrence grades and rates of arthritis progressed over time on radiographs (1.5 ± 0.7 vs. 2.4 ± 1.0;
p
< 0.001 and 78 % vs. 51 %;
p
= 0.01). Overall, 87 % of patients failed non-operative treatment.
Conclusions
Non-operative treatment of medial meniscus posterior horn root tears is associated with poor clinical outcome, worsening arthritis, and a relatively high rate of arthroplasty at 5-year follow-up. Female gender was associated with lower subjective scores and higher rate of arthroplasty. The current study provides a natural history benchmark for clinical outcomes that can be expected in patients with medial meniscus posterior horn root tears undergoing non-operative treatment and helps in counselling patients with these types of injuries.
Level of evidence
IV.
Small molecule organocatalysts are abundant in all living organisms. However, their use as organocatalysts in cells has been underexplored. Herein, we report that organocatalytic aldol chemistry can ...be interfaced with living Escherichia coli to enable the α-methylenation of cellular aldehydes using biogenic amines such as L-Pro or phosphate. The biocompatible reaction is mild and can be interfaced with butyraldehyde generated from D-glucose via engineered metabolism to enable the production of 2-methylenebutanal (2-MB) and 2-methylbutanal (2-MBA) by anaerobic fermentation, and 2-methylbutanol (2-MBO) by whole-cell catalysis. Overall, this study demonstrates the combination of non-enzymatic organocatalytic and metabolic reactions in vivo for the sustainable synthesis of valuable non-natural chemicals that cannot be accessed using enzymatic chemistry alone.
The illegal cultivation of cannabis in the United States has a long history, the weight of which is currently propelling a number of US states to legalize and regulate the plant after more than ...eighty years of outright prohibition. While each region has its own distinct history with the crop, this article outlines the history of cannabis cultivation in three parts of the country – the Midwest, South, and West – in an attempt to map out the driving social, economic, geographic, and environmental forces of illegal (and in some cases, legal) cannabis cultivation in the United States. Understanding how the US became one of the premier cannabis-growing regions of the world in the late twentieth and twenty-first centuries will help scholars pinpoint major themes in the world history of cannabis, such as its adoption and distribution by marginalized peoples, its transnational appeal in a globalized capitalist system, and how the plant embeds itself within the urban and rural ecology of human civilization. With a clearer picture of these themes, cannabis scholarship can better inform future studies, discussions, and public policy related to the plant.
Purpose
Medial meniscus posterior root tears (MMPRTs) are recognized as a source of pain and dysfunction, but treatment options remain a challenge. The purpose of the study was to determine (1) the ...efficacy of partial meniscectomy to treat MMPRTs compared to a matched group of non-operatively treated MMPRTs, and (2) risk factors for worse clinical and radiographic outcome.
Methods
This retrospective comparative study was performed to include patients with complete, isolated MMPRTs with documented clinical symptoms and were treated with arthroscopic partial meniscectomy (PMM) and a minimum 2-year follow-up. These patients were then matched by age, gender, and BMI to patients with the same diagnosis who were treated non-operatively. Clinical and radiographic outcomes were compared between the two groups. Analysis was performed to determine risk factors for worse clinical and radiographic outcome in the PMM group alone.
Results
Overall, 52 patients were included in the study. Twenty-six patients (9M:17F) with a mean age of 55 ± 9 and a mean BMI of 32.8 ± 5.3 were treated with PMM and followed for 5.5 ± 2.0 years (range 2.3–9.3 years). In the PMM group, final median Tegner score was 3, mean IKDC score was 67.8 ± 20, and more patients had grade II or higher arthritis at final follow-up than baseline (91.3 vs. 36%,
p
< 0.01). Overall, 14 of the 26 patients (54%) treated operatively progressed to total knee arthroplasty at a mean of 54.3 months. There was no significant difference in final Tegner scores, IKDC, K-L grades, progression to arthroplasty, or overall failure rate between the PMM group and non-operative group. Following PMM, female patients had lower final IKDC scores (44.0 ± 2.8 vs. 74.6 ± 16.7,
p
= 0.02) compared to males, as well as a higher rate of arthroplasty (70.6 vs. 20.0%,
p
= 0.009). Higher BMI correlated with lower IKDC scores (
r
= −0.91,
p
= 0.01) and meniscal extrusion was associated with higher rate of arthritis at final follow-up (
p
= 0.02).
Conclusion
Partial meniscectomy for a complete MMPRT provides no benefit in halting arthritic progression. Patients who undergo PMM for MMPRTs still progress to significant arthritis, poor clinical outcomes and a high arthroplasty rate (54%) at over 5-year follow-up. Female gender, increased BMI, and meniscus extrusion were associated with worse outcome.
Study design
Level III.
Distal radial fractures are extremely common injuries, yet many basic questions remain unanswered about their optimum management. Recently in the United Kingdom several guideline development groups ...have produced national standards and best-practice guidelines based on review of the best available evidence and expert knowledge. All guideline groups agree that when surgery is needed for dorsally displaced distal radial fractures, that can be reduced closed, K-wire fixation and cast immobilization, should be offered. Further research questions have been identified. The important findings and recommendations are summarized in this article.
During the first half of the twentieth century in the American West, Mexican and Mexican American farm workers grew and usedCannabis, the marijuana plant, to help navigate the physical, mental, and ...economic struggles they faced as exploited itinerant laborers. Their stories show that, while the capitalist framework of the agricultural landscape kept workers pinned to the bottom of the socioeconomic ladder, the landscape itself provided spaces where they could use traditional knowledge ofCannabisto climb that ladder, albeit illegally. The ensuing interactions between workers, plants, and the agricultural landscape gave birth to an illicit trade that remains culturally, economically, and environmentally relevant in the West today
Purpose
Medial patellofemoral ligament (MPFL) reconstruction and tibial tubercle osteotomy are commonly used to treat recurrent lateral patellar instability, yet there are limited available data on ...return to sport (RTS) following these procedures. The purpose of this study is to evaluate patient factors associated with excellent functional outcomes, including successful RTS, following surgical stabilization including MPFL reconstruction in competitive athletes with recurrent lateral patellar instability.
Methods
Athletes undergoing primary MPFL reconstruction for recurrent lateral instability from 2005 to 2013 were identified at a single institution. Concomitant procedures, such as tibial tubercle osteotomy (TTO), were included. Patient demographic information, including BMI, gender, age, and pre-injury Tegner score, was recorded. In addition, radiographs were reviewed for pre-operative patellar height (Caton–Deschamps index) and trochlear dysplasia (Dejour classification). All patients underwent a standardized rehabilitation/post-operative protocol, with isokinetic strength and functional testing being performed at 6 months post-operatively. Final Tegner scores, RTS status, subjective instability ratings, and Kujala scores were collected at a minimum of 2 years. Chi-squared analysis for categorical variables and Wilcoxon rank-sum analysis for continuous variables were used to determine the relationship between the previously mentioned patient and knee characteristics with isokinetic data, RTS status, or Kujala scores.
Results
Thirty-nine athletes (23 male, 16 female) at a mean age of 17.5 ± 2.9 years (range, 13–26) underwent primary MPFL reconstruction (32 autografts, seven allografts) for recurrent patellar instability with a mean follow-up of 47.0 ± 16.4 months. Sixteen patients (41%) underwent concomitant tibial tubercle osteotomies. Isokinetic data collected at 6 months post-operatively demonstrated mean knee flexion and extension strength deficits of 15.8 ± 10.1% and 21.4 ± 14.3%, respectively, compared to the contralateral leg (
p
< 0.001 for both). Patients who underwent concomitant tibial tubercle osteotomy (
p
= 0.04), males (
p
= 0.01) and those with patella alta (
p
= 0.04) had weaker 6-month isokinetic testing. Thirty-three of the thirty-nine (85%) athletes were able to RTS at a mean of 8.1 ± 3.9 months. Patients undergoing MPFL with concomitant TTO (
p
= 0.02) returned to sport at a slower rate. One patient (3%) reported an episode of recurrent dislocation requiring revision surgery. Kujala and Tegner scores at final follow-up were 91.1 ± 6.3 and 6 (range, 4–9), respectively.
Conclusion
Surgical stabilization including MFPL reconstruction for recurrent lateral patellar instability is an effective procedure for returning athletes to competitive sports. However, strength deficits persist at 6 months after surgery, especially in those undergoing concomitant TTO, which may delay return to sport. Physicians can use these results to counsel patients that return to competitive sports is safe with good clinical outcomes and low rate of recurrence at 4-year follow-up; however, predisposing factors, like a lateralized tibial tubercle, should be addressed if necessary, but athletes should be counselled that a slower recovery and longer return to sport time may be expected.
Level of evidence
IV.
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