Background: Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure. Hypothesis: We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively. Results: A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 ( P = .003) and KOOS ( P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months ( P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale ( P = .11). Conclusion: The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery. Registration: NCT02018354 ( ClinicalTrials.gov identifier)

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined. Purpose/Hypothesis: The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture. Study Design: Case-control study; Level of evidence, 3. Methods: Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level. Results: Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture. Conclusion: The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

SummaryStreptomyces coelicolor is a multicellular bacterium whose life cycle encompasses three differentiated states: vegetative hyphae, aerial hyphae and spores. Among the factors required for aerial development are the 'chaplins', a family of eight secreted proteins that coat the surface of aerial hyphae. Three chaplins (the 'long' chaplins, ChpA, B and C) possess an LAXTG-containing C-terminal sorting signal and are predicted sortase substrates. The five remaining 'short' chaplins are presumed to be associated with the cell surface through interactions with the long chaplins. We show here that two sortase enzymes, SrtE1 and SrtE2, cleave LAXTG-containing peptides at two distinct positions in vitro, and are required for cell wall anchoring of ChpC in vivo. srtE1/E2 double mutants are delayed in aerial hyphae formation, do not sporulate and fail to display all short chaplins on their aerial surfaces. Surprisingly, these mutant characteristics were not shared by a long chaplin mutant, which exhibited only modest delays in aerial development, leading us to revise the current model of chaplin-mediated aerial development. The sortase mutant phenotype, instead, appears to stem from an inability to transcribe aerial hyphae-specific genes, whose products have diverse functions. This suggests that sortase activity triggers an important, and previously unknown, developmental checkpoint.

BackgroundTotal knee arthroplasty using patient-specific instrumentation (TKA-PSI), which are disposable cutting block guides generated to fit each patient’s 3-dimensional knee anatomy, has been developed to treat patients with end-stage osteoarthritis of the knee. Surrogate markers such as radiographic malalignment have been well investigated, however, patient-important outcomes are not well examined to elucidate the efficacy of TKA-PSI. The aim of this review is to determine if TKA-PSI improves patient-reported outcome measures (PROM), surgery time, blood loss, transfusion and complications (e.g. surgical site infection, deep venous thrombosis, and revision TKA).MethodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and ongoing clinical trials. For PROMs, surgery time, blood loss, and transfusion rate, we included randomized controlled trials (RCT) comparing TKA-PSI and standard TKA to treat osteoarthritis of the knee. For complications, we also included non-randomized comparative studies (non-RCT).ResultsThis review includes 38 studies, 24 of which were RCT and 14 of which were non-RCT. These included a total of 3487 patients. The predominant population in the included studies highly reflected the general population, with 62% being female, aged over 60 and having end-stage osteoarthritis of the knee. TKA-PSI did not improve PROMs as compared to standard TKA for less than 1-year (mean difference 0.48, 95% confidence interval (CI) -1.92–0.97 in the Oxford knee score, mean 3-month follow-up) and for 1-year or more (mean difference 0.25, 95%CI − 4.39–4.89 in the WOMAC score, mean 29-month follow-up). TKA-PSI did not reduce surgery time (mean difference − 3.09 min, 95%CI -6.73–0.55). TKA-PSI decreased blood loss with a small effect size corresponding to a 0.4 g/dl hemoglobin decrease (95%CI 0.18–0.88), but did not decrease transfusion rate (risk difference − 0.04, 95%CI -0.09–0.01). TKA-PSI did not reduce complication rates (risk difference 0.00, 95%CI − 0.01–0.01 in the composite outcome).ConclusionsTKA-PSI does not improve patient-reported outcome measures, surgery time, and complication rates as compared to standard TKA. TKA-PSI decreases blood loss with a small effect, which is not enough to reduce transfusion rate.

Purpose of Review To present an updated systematic review of the indications and outcomes of open and arthroscopic labral reconstruction. Due to the increasing popularity and recognition, the arthroscopic procedure has gained in recent years, the aim was to assess for changes in indications, graft selection, and improvement in outcomes within the last 5 years. Recent Findings A total of nine eligible studies (six case series, one cohort, and two retrospective comparative studies) with a total of 234 patients (265 hips), and an average 12/16 (non-comparative studies) and 20/24 (comparative studies) quality on the MINORS score were included in this review. All patients underwent labral reconstruction, whether as primary surgery or revision (76% vs 24% respectively). There were 244 hips assessed at final follow-up (92%) with a reported mean range of 12 and 61 months. There were more graft variabilities found in this study compared with the previous review (iliotibial band allograft, gracilis tendon autograft, indirect head of rectus femoris autograft, semitendinosus allograft, peroneus brevis allograft, labrum allograft, ligamentum capitus femoris). Surgical approaches differed (open 7.9% (previously 18.7%), arthroscopic 86% (previously 81. 3 %), arthroscopic assisted mini-open technique (AAMOT) (6%)). Overall, improvement was observed in the patientreported outcomes and functional scores, with variability in their statistical significance. The failure rate or conversion to total hip arthroplasty (THA) decreased compared with the previous review (20% vs 9.5% [conversion to THA was 5.7% and revision surgery rate was 3. 8%]). Indications for labrum reconstruction remained similar (i.e., young, active patients with no or minimal arthritis (Tonnis 0-1), irreparable or ossified labrum, and hypotrophic < 2 mm or dysfunctional hypertrophic labrum > 8 mm). Summary According to recent evidence, hip labrum reconstruction is a new technique that showed short-and mid-term improvement in patient-reported outcomes and functional scores postoperatively. The primary indication for reconstruction remained similar over time. The failure rates and/or conversion to THA appear to have decreased over time. Long-term follow-up with higher quality studies was not available in the literature based on this review. Level of evidence 2