A randomized controlled trial of PEEK versus titanium interference screws for anterior cruciate ligament reconstruction with 2-year follow-up

Purpose: To compare the clinical performance of ACL reconstruction with PEEK and titanium interference screws at 2 years and to evaluate a novel method of measuring tunnel volume. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 133 patients underwent arthroscopic ACL reconstruction with 4-strand hamstring autografts and were randomized to have titanium or PEEK interference screws for femoral and tibial tunnel fixation. At 2 years, subjective Lysholm and International Knee Documentation Committee scores were assessed and clinical examination performed. At 12 months, MRI was performed to assess graft incorporation and cyst formation, and a novel technique was employed to measure tunnel volumes. Results: There were no significant differences in graft rerupture rate, contralateral ACL rupture rate, subjective outcomes, or objective outcomes. In the titanium and PEEK groups, MRI demonstrated high overall rates of graft integration (96%-100% and 90%-93%, respectively) and ligamentization (89% and 84%) and low rates of synovitis (22% and 10%) and cyst formation (0%-18% and 13%-15%). There was a higher proportion of patients with incomplete graft integration within the femoral tunnel in the PEEK group as compared with the titanium group (10% vs 0%, P = .03); however, the authors suggest that metal artifact precluded proper assessment of the graft in the titanium group by MRI. Tunnel volumes also appeared to be equivalent in the 2 groups and were measured with a novel technique that was highly reproducible in the PEEK group secondary to the absence of flare. Conclusion: Two-year clinical analysis of PEEK interference screws for femoral and tibial fixation of ACL reconstructions showed equivalent clinical performance to titanium interference screws. Given the excellent mechanical characteristics, biological compatibility, and absence of metal artifact on MRI, PEEK has become our material of choice for interference screw fixation in ACL reconstruction

Fifteen-year survival of endoscopic anterior cruciate ligament reconstruction in patients aged 18 years and younger

Background: The current body of literature surrounding anterior cruciate ligament (ACL) survival and the variables contributing to further ACL injuries after primary ACL reconstruction in children and adolescents is limited, with no long-term evidence examining the incidence and contributing factors of further ACL injuries in this younger patient population. Purpose: To determine the long-term survival of the ACL graft and the contralateral ACL (CACL) after primary reconstruction in patients aged 18 years and to identify the factors that increase the odds of subsequent ACL injuries. Study Design: Case series; Level of evidence, 4. Methods: Patients having undergone primary ACL reconstruction at age 18 years between 1993 and 1998 who were included in a prospective database by a single surgeon were considered for this study. Single-incision endoscopic ACL reconstruction was performed with either an autologous bone–patellar tendon–bone graft or a hamstring tendon graft. At a minimum of 15 years after ACL reconstruction, patients completed a subjective survey involving the International Knee Documentation Committee (IKDC) questionnaire in addition to questions regarding current symptoms, further ACL injuries, family history of ACL injury, and current level of activity. Results: A total of 288 adolescents (age range, 13-18 years) met the inclusion criteria, of whom 242 (84%) were reviewed at a mean of 16 years and 6 months after ACL reconstruction. Of these patients, 75 (31%) sustained a further ACL injury: 27 (11.2%) suffered an ACL graft rupture, 33 suffered a CACL injury (13.6%), and 15 sustained both an ACL graft rupture and a CACL injury (6.2%) over 15 years. Survival of the ACL graft was 95%, 92%, 88%, 85%, and 83% at 1, 2, 5, 10, and 15 years, respectively, and survival of the CACL was 99%, 98%, 90%, 83%, and 81%, respectively. Survival of the ACL graft was less favorable in those with a family history of ACL injury than in those without a family history (69% vs 90%, respectively; hazard ratio [HR], 3.6; P = .001). Survival of the CACL was less favorable in male patients than in female patients (75% vs 88%, respectively; HR, 2.1; P = .03) and in those who returned to competitive team ball sports than in those who did not (78% vs 89%, respectively; HR, 2.3; P = .05). Conclusion: After ACL reconstruction in patients aged 18 years, a further ACL injury occurred in 1 in 3 patients over 15 years. The 15-year survival rate of the ACL graft was 83%, and the 15-year survival rate of the CACL was 81%. The ACL graft and CACL were most vulnerable within the first 5 years after index surgery. A family history of ACL rupture significantly increased the risk for ACL graft ruptures, and a CACL injury was more common in male patients and those who returned to team ball sports. High IKDC scores and continued participation in sports were maintained over the long term after ACL reconstruction in the adolescent population

5-Year survival of pediatric anterior cruciate ligament reconstruction with living donor hamstring tendon grafts

Background: It is well accepted that there is a higher incidence of repeat anterior cruciate ligament (ACL) injuries in the pediatric population after ACL reconstruction (ACLR) with autograft tissue compared with adults. Hamstring autograft harvest may contribute to the risk for repeat ACL injuries in this high functional demand group. A novel method is the use of a living donor hamstring tendon (LDHT) graft from a parent; however, there is currently limited research on the outcomes of this technique, particularly beyond the short term. Purpose/Hypothesis: The purpose was to determine the medium-term survival of the ACL graft and the contralateral ACL (CACL) after primary ACLR with the use of an LDHT graft from a parent in those aged less than 18 years and to identify factors associated with subsequent ACL injuries. It was hypothesized that ACLR with the use of an LDHT provides acceptable midterm outcomes in pediatric patients. Study Design: Case series; Level of evidence, 4. Methods: Between 2005 and 2014, 247 (of 265 eligible) consecutive patients in a prospective database, having undergone primary ACLR with the use of an LDHT graft and aged less than 18 years, were included. Outcomes were assessed at a minimum of 2 years after surgery including data on ACL reinjuries, International Knee Documentation Committee (IKDC) scores, and current symptoms, as well as factors associated with the ACL reinjury risk were investigated. Results: Patients were reviewed at a mean of 4.5 years (range, 24-127 months [10.6 years]) after ACLR with an LDHT graft. Fifty-one patients (20.6%) sustained an ACL graft rupture, 28 patients (11.3%) sustained a CACL rupture, and 2 patients sustained both an ACL graft rupture and a CACL rupture (0.8%). Survival of the ACL graft was 89%, 82%, and 76% at 1, 2, and 5 years, respectively. Survival of the CACL was 99%, 94%, and 86% at 1, 2, and 5 years, respectively. Survival of the ACL graft was favorable in patients with Tanner stage 1-2 at the time of surgery versus those with Tanner stage 3-5 at 5 years (87% vs 69%, respectively; hazard ratio, 3.7; P = .01). The mean IKDC score was 91.7. A return to preinjury levels of activity was reported by 59.1%. Conclusion: After ACLR with an LDHT graft from a parent in those aged less than 18 years, a second ACL injury (ACL graft or CACL injury) occurred in 1 in 3 patients. The 5-year survival rate of the ACL graft was 76%, and the 5-year survival rate of the CACL was 86%. High IKDC scores and continued participation in sports were maintained over the medium term. Importantly, there was favorable survival of the ACL graft in patients with Tanner stage 1-2 compared with patients with Tanner stage 3-5 over 5 years. Patients with Tanner stage 1-2 also had a significantly lower incidence of second ACL injuries over 5 years compared with those with Tanner stage 3-5, occurring in 1 in 5 patients. Thus, an LDHT graft from a parent is an appropriate graft for physically immature children

Twenty-year outcome of a longitudinal prospective evaluation of isolated endoscopic anterior cruciate ligament reconstruction with patellar tendon or hamstring autograft

Background: Long-term prospective follow-up studies of single-incision endoscopic anterior cruciate ligament (ACL) reconstruction are limited and may include confounding factors. Purpose: This longitudinal prospective study reports the outcomes of isolated ACL reconstruction using middle-third patellar tendon autografts in 90 patients over 20 years. Study Design: Case series; Level of evidence, 4. Methods: Between January 1993 and April 1994, a total of 90 patients met study inclusion criteria: evaluation at 1, 2, 3, 4, 5, 7, 10, 15, and 20 years after surgery. Exclusion criteria were associated ligamentous injuries requiring surgery, previous meniscectomy or meniscal injuries requiring more than one-third meniscectomy, chondral injuries, and an abnormal contralateral knee. Results: At 20 years, 32 (36%) patients had sustained another ACL injury: 8 (9%) to the index limb and 27 (30%) to the contralateral limb (3 injuring both knees). The mean International Knee Documentation Committee (IKDC) score was 86. Of the patients, 50% participated in strenuous/very strenuous activities, and kneeling pain was present in 63%. Radiographic degenerative change was found in 61%; 20% had IKDC grade C, and 0% had grade D. The IKDC clinical examination revealed that 95% had a normal/nearly normal knee. Significant sex differences existed: when compared with male patients, female patients were less likely to reinjure the reconstructed ACL (18% vs 2%, respectively; P = .01), reported poorer IKDC subjective scores (90 vs 83, respectively; P = .03), had more activity-related pain (20% vs 57%, respectively; P = .02), and were less likely to participate in strenuous activities (66% vs 35%, respectively; P = .009). ACL graft survival was not related to age. Patients \u3c18 years old had an increased odds ratio (3.2) for rupturing the contralateral ACL. A coronal graft angle \u3c17° increased the risk of failure compared with an angle \u3e17° (77% vs 96% survival, respectively) by a factor of 8.5. Conclusion: Injuries more commonly occurred in the contralateral ACL than in the reconstructed ACL graft, and the most significant predictor of a contralateral ACL injury was age \u3c18 years. The most significant predictor of an ACL graft rupture was a coronal graft angle \u3c17°. Female patients had lower rerupture rates, poorer subjective scores, and decreased participation in strenuous activities, putting the graft at a lower risk of failure. Kneeling pain remained persistent over 20 years. Radiographic osteoarthritis was evident in 61% of patients, but symptomatic osteoarthritic symptoms were rarely reported

Feedback from activity trackers improves daily step count after knee and hip arthroplasty: A randomized controlled trial

Background: Commercial wrist-worn activity monitors have the potential to accurately assess activity levels and are being increasingly adopted in the general population. The aim of this study was to determine if feedback from a commercial activity monitor improves activity levels over the first 6 weeks after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Methods: One hundred sixty-three consecutive subjects undergoing primary TKA or THAwere randomized into 2 groups. Subjects received an activity tracker with the step display obscured 2 weeks before surgery and completed patient-reported outcome measures (PROMs). On day 1 after surgery, participants were randomized to either the “feedback (FB) group” or the “no feedback (NFB) group.” The FB group was able to view their daily step count and was given a daily step goal. Participants in the NFB group wore the device with the display obscured for 2 weeks after surgery, after which time they were also able to see their daily step count but did not receive a formal step goal. The mean daily steps at 1, 2, 6 weeks, and 6 months were monitored. At 6 months after surgery, subjects repeated PROMs and daily step count collection. Results: Of the 163 subjects, 95 underwent THA and 68 underwent TKA. FB subjects had a significantly higher (P \u3c .03) mean daily step count by 43% in week 1, 33% in week 2, 21% in week 6, and 17% at 6 months, compared with NFB. The FB subjects were 1.7 times more likely to achieve a mean 7000 steps per day than the NFB subjects at 6 weeks after surgery (P ¼ .02). There was no significant difference between the groups in PROMs at 6 months. Ninety percent of FB and 83% of NFB participants reported that they were satisfied with the results of the surgery (P ¼ .08). At 6 months after surgery, 70% of subjects had a greater mean daily step count compared with their preoperative level. Conclusion: Subjects who received feedback from a commercial activity tracker with a daily step goal had significantly higher activity levels after hip and knee arthroplasty over 6 weeks and 6 months, compared with subjects who did not receive feedback in a randomized controlled trial. Commercial activity trackers may be a useful and effective adjunct after arthroplasty

Twenty-year outcomes of a longitudinal prospective evaluation of isolated endoscopic anterior cruciate ligament reconstruction with patellar tendon autografts

Background: Long term prospective follow up studies of single-incision endoscopic anterior cruciate ligament reconstruction are limited and may include confounding factors. Objectives: This longitudinal prospective study reports the outcome of isolated anterior cruciate ligament (ACL) reconstruction using middle-third patellar tendon autograft in 90 patients over 20 years. Study design: Case series; Level of evidence, 4. Methods: Between January 1993 and April 1994, 90 patients met study inclusion criteria, evaluation 1,2,3,4,5,7,10,15 and 20 years post-surgery. Exclusion criteria: associated ligamentous injury requiring surgery, previous meniscectomy; meniscal injury meniscectomy more than 1/3; chondral injury; and an abnormal contralateral knee. Results: At 20 years, 32(36%) patients had sustained another ACL injury, 8(9%) to the index limb and 27(29%) to the contralateral limb (3 injuring both knees). Mean IKDC score was 86, 50% participated in strenuous/very strenuous activities, kneeling pain was present in 63%. Radiographic degenerative change was found in 61%, 20% IKDC Grade C, 0% Grade D. IKDC clinical examination revealed 95% had a normal/nearly normal knee. Significant gender differences existed: females were less likely to re-injure the reconstructed ACL (18%v2%, p=0.01), reported poorer IKDC subjective score (90v83, p=0.03), had more activity related pain (57%v20%, p=0.02), and less likely to participate in strenuous activity (35v66, p=0.01). ACL graft survival was not related to age. Patients \u3c18years old had an increased odd ratio (3.2) for rupturing the contralateral ACL. Coronal graft angles \u3c17 degrees had increased risk of failure compared to those over 17 degrees (96% v 77%), by a factor of 8.5. Conclusion: Injury commonly occurred in the contralateral ACL than the reconstructed ACL graft, the most significant predictor of contralateral ACL injury is age under 18yrs. The most significant predictor of ACL graft rupture is a coronal graft angle of less than 17 degrees. Females had lower re- rupture rates, poorer subjective scores, decreased participation in strenuous activity, putting the graft at less risk of failure. Kneeling pain remained persistent over 20 years. Radiographic osteoarthritis was evident in 61% of subjects but symptomatic osteoarthritic symptoms were rarely reported

Bioabsorbable versus titanium screws in anterior cruciate ligament reconstruction using hamstring autograft: a prospective, blinded, randomized controlled trial with 5-year follow-up

Background: Longer term studies of bioabsorbable screws for ACL reconstruction are reported, but results are specific to the exact screw material and design. Titanium and PLLA-HA screw outcomes have been compared only to 2 years. Purpose: The aim of this study was to compare the clinical and radiological outcomes of PLLAHA screw (BS) versus a titanium screw (TS), for hamstring tendon anterior cruciate ligament reconstruction over 5 years. We hypothesized that there are no differences in clinical scores, and tunnel widening, between the BS and the TS groups, and that the PLLA-HA screw as seen on MRI should show high grade resorption and ossification response over 5 years. Methods: 40 patients undergoing ACLR were randomized to receive either a PLLA-HA screw (BS group) or a Titanium screw (TS group) for ACL fixation. Blinded evaluation was performed at 2 & 5 years with IKDC & Lysholm knee score, KT-1000 arthrometer, single legged hop test, and MRI to evaluate tunnel and screw volumes, peri-screw ossification, graft integration and cyst formation. Results: There was no difference in any clinical outcome measure at 2 or 5 years between the 2 groups. At 2 years, the BS femoral tunnel was smaller than the TS tunnel (p=0.02) and at 5 years, there was no difference. At 2 years the femoral BS screw was a mean 76% of its original volume and by 5 years, 36%. At 2 years the tibial BS screw mean volume was 68% of its original volume and by 5 years, 46%. At 5 years BS group 88% of femoral tunnels and 56% of tibial tunnels demonstrated a significant ossification response. There was no increase in cyst formation in the BS group and no screw breakages. Conclusion: Our study has shown equivalent clinical results between BS and TS groups at 2 and 5 years. This PLLA-HA screw was not associated with increased tunnel widening or cyst formation when compared with the titanium screw. The PLLA-HA screw demonstrated progressive screw resorption and gradual, but incomplete ossification over 5 years

Human melanomas and ovarian cancers overexpressing mechanical barrier molecule genes lack immune signatures and have increased patient mortality risk.

We have identified eight genes whose expression in human melanoma metastases and ovarian cancers is associated with a lack of Th1 immune signatures. They encode molecules with mechanical barrier function in the skin and other normal tissues and include filaggrin (FLG), tumor-associated calcium signal transducer 2 (TACSTD2), and six desmosomal proteins (DST, DSC3, DSP, PPL, PKP3, and JUP). This association has been validated in an independent series of 114 melanoma metastases. In these, DST expression alone is sufficient to identify melanomas without immune signatures, while FLG and the other six putative barrier molecules are overexpressed in a different subset of melanomas lacking immune signatures. Similar associations have been identified in a set of 186 ovarian cancers. RNA-seq data from 471 melanomas and 307 ovarian cancers in the TCGA database further support these findings and also reveal that overexpression of barrier molecules is strongly associated with early patient mortality for melanoma (p = 0.0002) and for ovarian cancer (p < 0.01). Interestingly, this association persists for FLG for melanoma (p = 0.012) and ovarian cancer (p = 0.006), whereas DST overexpression is negatively associated with CD8(+) gene expression, but not with patient survival. Thus, overexpression of FLG or DST identifies two distinct patient populations with low immune cell infiltration in these cancers, but with different prognostic implications for each. These data raise the possibility that molecules with mechanical barrier function in skin and other tissues may be used by cancer cells to protect them from immune cell infiltration and immune-mediated destruction

3D imaging and flow characterization of the pore space of carbonate core samples

Carbonate rocks are inherently heterogeneous having been laid down in a range of depositional environments and having undergone significant diagenesis. They are particularly difficult to characterise as the pore sizes can vary over orders of magnitudes and connectivity of pores of different scales can impact greatly on flow properties. For example, separate vuggy porosity in an underlying matrix pore system can increase the porosity, but not the permeability and lead to large residual oil saturations due to trapping in vugs. A touching vug network can have a dramatic effect on permeability and lead to higher recoveries. In this paper we image a range of carbonate core material; from model carbonate cores to core material from outcrops and reservoirs via 3D via micro-CT. Image-based calculations of porosity, MICP and permeability on 3D images of the carbonate systems are directly compared to experimental data from the same or sister core material and give good agreement. The carbonate systems studied include samples with well connected macroporous systems and other where the macroporosity is poorly connected. Simulation of permeability on these systems and direct analysis of local flow properties within the system allows one to directly illustrate the important role of the connectivity of macropores on flow properties. Pore network models generated from the images illustrate the varied topology obtained in different carbonate samples and show a dramatic difference when compared to clastic samples. Many carbonate samples can include a significant proportion of microporosity (pores of 2 microns or less in extent) which are not directly accessible via current micro-CT capabilities. We discuss how one can map the structure and the topology of microporous regions crucial in studies of flow, production and recovery in carbonates. A hybrid numerical scheme is developed to measure the contribution of microporosity to the overall core permeability. Overall these results show the important role of identifying the connectivity of the pore sizes in dictating the single phase flow properties. Implications to two phase relative permeability and recovery are briefly discussed