Editorial commentary: The acrid bioscrew in anterior cruciate ligament reconstruction of the knee

Bioresorbable screws have been widely adopted for graft fixation in knee anterior cruciate ligament (ACL) reconstruction on the promise of screw resorbtion and replacement by bone. When considering the value of bioresorbable screws, it is imperative to understand that the “A” in PGA and PLA, the base ingredient of all bioscrews, is for Acid. All resorb by a process of hydrolysis; the speed and extent of resorbtion is determined by both the acidity of the screw and the environment in which it is placed. Regrettably, the promise of reliable, predictable screw resorbtion and replacement by bone remains elusive, despite the addition of “osteoconductive” materials. For the most part, bioresorbables are associated with good clinical outcomes for ACL reconstruction; they are not “dangerous,” just disappointing with respect to bony replacement. We propose that nonresorbing inert plastics such as PEEK (polyether ether ketone) may be better suited for the purpose of graft fixation devices for ACL reconstruction

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

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

EFFECT OF HAMSTRING TENDON AUTOGRAFT FOR ACL RECONSTRUCTION ON KNEE EXTENSION/FLEXION STRENGTH DEFICITS AND KNEE FUNCTION

INTRODUCTION Regaining full rehabilitation of the quadriceps (Q) and hamstring (H) muscles following ACL reconstruction is a major contributing factor to athletes returning to pre-injury activity levelsl. A current technique of ACL reconstruction involves harvesting the ,H tendons which are used as a graft to replace the ruptured ACL. However, H tendon harvesting has been shown to result in Q and H muscle strength deficits2. It was the purpose of this study to determine knee extension/flexion strength deficits following H tendon harvesting from the ACL injured compared to the uninjured Limb. A secondary purpose was to determine if there was any relationship between lower limb strength deficits and subjective ratings of knee function. METHODS Thirty unilateral, isolated subacute ACL deficient athletes (mean age = 24.7 4.9 years) who were patients of the North Sydney Orthopaedic and Sports Medicine Centre were randomly assigned to an experimental (E) and a control (C) group. Experimental subjects had the H tendon graft to reconstruct their ACL harvested from their uninjured limb whereas control subjects had the H tendon graft harvested from the ACL injured limb. Using the protocol of Kannus et al.3, H and Q strength for each subject was assessed using a CybexII+ isokinetic dynamometer pre-surgery and at 12 weeks and 6 months post-surgery. Strength deficits were then calculated using the Strength Scoring Scale3. Subjective ratings of knee function were collected using the International Knee Documentation Committee Form (IKDC) at the same three testing sessions. RESULTS ' h o way repeated ANOVA results indicated a significant main effect of test week on total strength deficits (F2,46 = 15.625, p < 0.0001). Post hoc analysis indicated mean strength deficit scores at 12 week post-surgery testing (27.4) were significantly less than pre-surgery (37.5) or 6 months (5 1.15) with 6 months scores being significantly higher than pre-surgery scores. ANOVA on ranks revealed a main effect of test week on IKDC scores (E: H2 = 20.724, p d.001; C: H2 = 26.808, p < 0.001) where both subject groups rated their knee function significantly higher at 12 weeks and 6 months post-surgery compared to pre-surgery. A significant negative correlation was found between strength score and IKDC score (r = -0.28; p = 0.01); ie, lower strength deficits were associated with higher ratings of knee function. CONCLUSIONS Strength deficits following H tendon harvesting are evident, irrespective of whether the graft is harvested from the ACL injured or uninjured limb, with lower strength deficits being associated with better knee function ratings. Whether minimizing strength deficits in the ACL reconstructed limb by taking the graft from the contralateral limb provides greater protection for the new H graft is yet to be determined. REFERENCES Shelbourne KD & Rowdon GA (1994). Sports Med 17(2): 132- 140. Marder R et al. (1991). Am J Sports Med 19(5): 187-194. Kannus Petal. (1987). Scand J Sports Sci 9(1): 9-13

Reflecting on pictorial spaces: an investigation into ambiguous spatial effects created through the use of reflective materials, fragmented abstract form and oblique linear structures.

This practice-led art research project investigates the relationships between geometric abstract painting, architecture and urban space. The outcome of the research is an exhibition of large-scale and medium sized geometric abstract paintings on canvas that explore issues of reflection and spatial deformation. Compositions drawing from the spatialities of contemporary architecture and urban space are examined through the use of reflective materials, fragmented abstract form and irregular structuring to create a range of spatial interpretations intended to engage and manipulate the viewer’s perceptions of illusory space. The project focuses on the inventive uses of reflective painting materials and recently developed synthetic colours influenced by digital technologies and high-gloss surface qualities. Innovative possibilities and opportunities in contemporary abstract painting practice are investigated through the use of newly developed commercial paint materials, pigments and mediums to create new perceptual and physiological experiences for the viewer. From the position of being a contemporary abstract painter I investigate key issues of spatial unease, disorientation and instability experienced in contemporary architecture and urban space, in order to produce highly ambiguous pictorial spatial experiences in my work, including infinite reflections, permutations and deformations. This project contributes original research to the field of abstract painting, and produces a new body of knowledge about pictorial spatial structures, colours and surface effects that generate disorientating viewing experiences and build on the relationship between abstract painting, architecture and urban space

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

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