20-Year Outcomes of High Tibial Osteotomy: Determinants of Survival and Functional Outcome.

BACKGROUND: High tibial osteotomy (HTO) is a successful joint-preserving procedure for the treatment of medial compartment osteoarthritis. Long-term survivorship of HTO ranges from 40% to 85%. There are consistent factors that predict failure. PURPOSE: To determine the 20-year survival of HTO and identify predictors of failure. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 100 consecutive patients with medial bone-on-bone arthritis were prospectively studied to provide long-term patient-reported outcome measures after lateral closing-wedge HTO and determine the time to failure. Failure was defined as conversion to arthroplasty (total knee arthroplasty or unicompartmental knee arthroplasty) or revision HTO. RESULTS: At 20 years, HTO survival was determined in 95 patients, and 5 were lost to follow-up. The overall survivorship of HTO at 20 years was 44%. The significant factors that were associated with better survivorship were age <55 years, body mass index <30, and Western Ontario and McMaster Universities Osteoarthritis Index pain score >45. These factors were used to define the favorable candidates. In the favorable candidates, survivorship was 100% at 5 years, after which there was a gradual decline to 62% survival at 20 years. Of those with HTO survival, 32 of 33 (97%) reported satisfaction with surgery, with a mean Knee injury and Osteoarthritis Outcome Score Pain score of 91 and Activities of Daily Living score of 97. CONCLUSION: HTO is a successful surgical option to treat medial compartment osteoarthritis and prevent the need for arthroplasty in young patients. The most suitable candidates for HTO are aged <55 years, are not obese, and have not progressed to severe symptomatic disability.

Repeat Anterior Cruciate Ligament Injury and Return to Sport in Australian Soccer Players After Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autograft.

BACKGROUND: Soccer is the most commonly played team sport in the world and a high-risk sport for anterior cruciate ligament (ACL) injury and subsequent ACL reconstruction (ACLR). PURPOSE: To assess the rate of further ACL injury in patients who have undergone ACLR with hamstring tendon autograft after soccer injuries in Australia and to determine factors associated with repeat ACL injury and return to soccer. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: From a prospectively collected database, a series of 1000 consecutive ACLRs using hamstring autografts performed in soccer players were identified. Patients were surveyed at a minimum 5 years after reconstruction, including details of further ACL injuries to either knee, return to soccer or other sports, and psychological readiness per the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) scale. RESULTS: Of the 862 participants reviewed, ACL graft rupture occurred in 85 (10%) and contralateral ACL rupture in 68 (8%) within 5 years after the reconstruction. The 5-year ACL graft survivorship was 94% for females and 88% for males. The survivorship of the contralateral ACL was 92% for males and 90% for females. When compared with those aged >25 years, the odds of ACL graft rupture was increased by 4 to 5 times in those aged 19 to 25 years and 3 to 7 times in those ≤18 years. Further ACL injury to the graft or contralateral knee occurred in 44% of males aged ≤18 years. Risk factors for further ACL injury were younger age at time of surgery, male sex, and return to soccer. Graft diameter did not influence ACL graft rupture rates, and 70% of patients returned to soccer after ACLR. The mean ACL-RSI score was 59, and patients who reported more fear of reinjury on this scale were less likely to have returned to soccer. CONCLUSION: The prevalence of ACL graft rupture (10%) and contralateral ACL rupture (8%) was near equivalent over 5 years in this large cohort of mostly recreational Australian soccer players. ACLR with hamstring autograft is a reliable procedure, allowing 70% of patients to return to soccer in this high-risk population. Risk factors for further ACL injury are progressively younger age at time of surgery, male sex, and return to soccer. Graft diameter was not a factor in ACL graft rupture, indicating that other factors, particularly age, are of primary importance.

Surgery for Osteoarthritis: Total Joint Arthroplasty, Realistic Expectations of Rehabilitation and Surgical Outcomes: A Narrative Review.

This narrative review highlights the prevalence of osteoarthritis as a chronic disease that directly contributes to the ever-growing health care expenditure to treat this condition. The increasing demand of total joint arthroplasty globally is explained in conjunction with the importance of understanding candidate suitability for arthroplasty surgery in order to maximize surgical outcomes and self-reported patient satisfaction after the surgery. Rehabilitation care following total hip arthroplasty and total knee arthroplasty, particularly the inappropriate use of inpatient rehabilitation service, is also explained, in addition to the enhanced recovery after surgery.

Improvement in Sleep Patterns After Hip and Knee Arthroplasty: A Prospective Study in 780 Patients.

BACKGROUND: This study assessed change in sleep patterns before and after total hip arthroplasty (THA) and total knee arthroplasty (TKA) and its relationship to patient-reported outcome measures (PROMs). METHODS: Between July 2016 and June 2018, surgical data and PROMs were collected on 780 subjects before and 12 months after THA or TKA. PROMs included Knee Injury and Osteoarthritis Outcome Score, Hip Disability and Osteoarthritis Outcome Score, patient satisfaction, and 2 questions from the Pittsburgh Sleep Quality Index. RESULTS: Before surgery, 35% (270 of 780) reported poor quality sleep. Sleep quality and duration were worse in females over males, and in THA patients (39%) over TKA patients (30%; P = .011). Of those reporting bad sleep, 74% (201 of 270) were improved after arthroplasty. Satisfaction was higher in subjects reporting good sleep quality (626 of 676; 93%) compared with those reporting bad sleep quality (67 of 86; 78%) (P = .001). Sleep was positively correlated with better Hip Disability and Osteoarthritis Outcome Score/Knee Injury and Osteoarthritis Outcome Score (r = 0.2-0.3). CONCLUSION: Improvement in sleep quality and duration can be expected after THA and TKA and is associated with better outcome scores and satisfaction.

Allograft Donor Characteristics Significantly Influence Graft Rupture After Anterior Cruciate Ligament Reconstruction in a Young Active Population.

BACKGROUND: Graft selection in anterior cruciate ligament (ACL) surgery can be difficult in a young active population given their high rates of reinjury. Allografts allow for control over graft size and reduce morbidity of autograft harvest. There are mixed results about the use of allograft in the literature; however, the influence of the properties of the allograft on outcomes has not been considered. HYPOTHESIS: ACL reconstruction with allografts from older donors will have a higher rate of graft rupture when compared with allograft from young donors. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients (N = 211) aged 13 to 25 years underwent primary ACL reconstruction with fresh-frozen nonirradiated allograft. Four graft types were used: patellar tendon, Achilles tendon, tibialis anterior, and tibialis posterior. Details were collected on allograft donor age and sex. At a minimum of 24 months, patients were evaluated for any further injuries and subjective analysis by International Knee Documentation Committee (IKDC) questionnaire. RESULTS: ACL graft rupture occurred in 23.5%. When grafts were separated into single strand (patellar and Achilles tendon) and multistrand (tibialis anterior and posterior), there was a significantly higher rate of reinjury in the single-strand grafts (29.9% vs 11%; P = .014). Grafts from female donors aged ≥50 years had significantly higher rates of ACL graft rupture (52.6%; P = .003) with increased odds by 6.7 times when compared with grafts from male donors aged <50 years. There was no significant difference in mean IKDC scores among the groups based on the age and sex of the allograft donor. CONCLUSION: The age and sex of the allograft donor and the morphology of the graft significantly influenced the rate of ACL graft rupture in young active patients. Tendons from female donors aged ≥50 years should be avoided given the higher rerupture rates as compared with male donors of any age and younger females.

Bioabsorbable Versus Titanium Screws in Anterior Cruciate Ligament Reconstruction Using Hamstring Autograft: A Prospective, Randomized Controlled Trial With 13-Year Follow-up.

BACKGROUND: Bioabsorbable screws for anterior cruciate ligament reconstruction (ACLR) have been a popular choice, with theoretical advantages in imaging and surgery. Titanium and poly-L-lactic acid with hydroxyapatite (PLLA-HA) screws have been compared, but with less than a decade of follow-up. PURPOSE/HYPOTHESIS: The purpose was to compare long-term outcomes of hamstring autograft ACLR using either PLLA-HA screws or titanium screws. We hypothesized there would be no difference at 13 years in clinical scores or tunnel widening between PLLA-HA and titanium screw types, along with high-grade resorption and ossification of PLLA-HA screws. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Forty patients undergoing ACLR were randomized to receive either a PLLA-HA screw or a titanium screw for ACL hamstring autograft fixation. Blinded evaluation was performed at 2, 5, and 13 years using the International Knee Documentation Committee score, Lysholm knee score, and KT-1000 arthrometer. Magnetic resonance imaging (MRI) was performed at 2 or 5 years and 13 years to evaluate tunnel volumes, ossification around the screw, graft integration, and cyst formation. Computed tomography (CT) of patients with PLLA-HA was performed at 13 years to evaluate tunnel volumes and intratunnel ossification. RESULTS: No differences were seen in clinical outcomes at 2, 5, or 13 years between the 2 groups. At 13 years, tibial tunnel volumes were smaller for the PLLA-HA group (2.17 cm3) compared with the titanium group (3.33 cm3; P = .004). By 13 years, the PLLA-HA group had complete or nearly complete resorption on MRI or CT scan. CONCLUSION: Equivalent clinical results were found between PLLA-HA and titanium groups at 2, 5, and 13 years. Although PLLA-HA screws had complete or nearly complete resorption by 13 years, tunnel volumes remained largely unchanged, with minimal ossification.

Transphyseal anterior cruciate ligament reconstruction using living parental donor hamstring graft: excellent clinical results at 2 years in a cohort of 100 patients.

PURPOSE: To determine outcomes of transphyseal ACL reconstruction using a living parental hamstring tendon allograft in a consecutive series of 100 children. METHODS: One hundred consecutive juveniles undergoing ACL reconstruction with a living parental hamstring allograft were recruited prospectively and reviewed 2 years after ACL reconstruction with IKDC Knee Ligament Evaluation, and KT1000 instrumented laxity testing. Skeletally immature participants obtained annual radiographs until skeletal maturity, and long leg alignment radiographs at 2 years. Radiographic Posterior tibial slope was recorded. RESULTS: Of 100 juveniles, the median age was 14 years (range 8-16) and 68% male. At surgery, 30 juveniles were graded Tanner 1 or 2, 21 were Tanner 3 and 49 were Tanner 4 or 5. There were no cases of iatrogenic physeal injury or leg length discrepancy on long leg radiographs at 2 years, despite a median increase in height of 8 cm. Twelve patients had an ACL graft rupture and 9 had a contralateral ACL injury. Of those without further ACL injury, 82% returned to competitive sports, IKDC ligament evaluation was normal in 52% and nearly normal in 48%. The median side to side difference on manual maximum testing with the KT1000 was 2 mm (range - 1 to 5). A radiographic PTS of 12° or more was observed in 49%. CONCLUSIONS: ACL reconstruction in the juvenile with living parental hamstring tendon allograft is a viable procedure associated with excellent clinical stability, patient-reported outcomes and return to sport over 2 years. Further ACL injury to the reconstructed and the contralateral knee remains a significant risk, with identical prevalence observed between the reconstructed and contralateral ACL between 12 and 24 months after surgery. LEVEL OF EVIDENCE: III (Cohort Study).

Utility of preoperative blood screening before hip and knee arthroplasty.

BACKGROUND: It is engrained in medical training that routine blood screening prior to arthroplasty is necessary for optimal patient care. There is little evidence to support their utility and the aggregate cost to the health system. The purpose of this study was to evaluate preoperative blood screening by identifying the frequency of an abnormal result and to examine the influence of age, gender and body mass index on the frequency of abnormal blood pathology. METHODS: This is a retrospective review of 1000 patients from a single centre who underwent elective primary hip or knee arthroplasty from 2015 to 2017. Abnormal blood results were identified and clinically relevant intervals were created for routine markers. RESULTS: A total of 939 patients had available pathology results with 84% identified as having an abnormal result and 47% having a clinically important range. Abnormal liver function tests and ferritin were most common. With increasing age, there was a significant increase in rates of abnormal clinically important range, renal dysfunction, abnormal haemoglobin and erythrocyte sedimentation rate. Males and patients with body mass index >40 had an increased rate of abnormal results, particularly liver function tests. CONCLUSION: The ordering of preoperative investigations prior to lower limb arthroplasty is recommended by the National Institute for Health and Care Excellence guidelines, alleviating concern of post-operative complications and covering medicolegal issues. Our study determined a high frequency of abnormal results, justifying routine blood screening is recommended prior to surgery, particularly for the elderly, males and obese patients.

A Randomized Controlled Trial of PEEK Versus Titanium Interference Screws for Anterior Cruciate Ligament Reconstruction With 2-Year Follow-up.

BACKGROUND: Graft fixation with interference screws for anterior cruciate ligament (ACL) reconstruction is a highly successful technique. Polyether ether ketone (PEEK) is a novel thermoplastic polymer with high biocompatibility and mechanical properties that mimic native bone, and it can be imaged on computed tomography or magnetic resonance imaging (MRI) without signal flare. 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.

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.

Side-to-Side Differences in Varus Thrust and Knee Abduction Moment in High-Functioning Individuals With Chronic Anterior Cruciate Ligament Deficiency.

BACKGROUND: There is evidence that frontal plane knee joint motion plays a crucial role in the pathogenesis of knee osteoarthritis, yet investigation of individuals with chronic anterior cruciate ligament-deficient (ACLD) knees remains sparse. PURPOSE: To investigate (1) if individuals with chronic ACLD knees demonstrate higher biomechanical measures of medial knee load as compared with their anterior cruciate ligament-intact (ACLI) knees, (2) if differences in static knee alignment of the ACLD knee will demonstrate a difference in the magnitude of biomechanical measures of medial knee load when compared with the ACLI knee, and (3) the side-to-side concordance of varus thrust among individuals with chronic ACLD knees. STUDY DESIGN: Descriptive laboratory study. METHODS: Participants were sourced from a metropolitan orthopaedic surgeon group. Those who met the inclusion criteria and agreed to participate underwent a 3-dimensional gait analysis assessment to measure knee adduction moment (KAM), knee flexion moment (KFM), KAM peaks, KAM impulse, and varus thrust. Frontal plane knee static alignment was measured with a digital inclinometer fixed to medical calipers. The participants were divided according to their static knee alignment (neutral, varus, and valgus) for subgroup analysis. Peak knee angular velocity and frontal plane knee angle were used to establish if a participant was walking with a knee thrust. An individual was deemed to have knee thrust during gait if the largest frontal plane knee movement coincided with the peak knee angular velocity that occurred within the first 30% of stance phase. RESULTS: Forty-five participants were recruited. The mean (SD) time from injury was 34.5 (55.6) months. ACLD knees did not demonstrate higher mean KAM and KFM ( P > .5) or early-stance peak KAM ( P = .3-.8) and KAM impulse ( P = .3-.9) as compared with ACLI knees as a whole group or when the varus, neutral, and valgus alignment subgroups were investigated separately. Twenty-three percent (n = 9) of the participants had a varus thrust at the ACLD or ACLI knee, 44% (n = 4) had a varus thrust at the ACLD knee, and 22% (n = 2) had varus thrust at both knees. CONCLUSION: There were no side-to-side differences in mean KAM and KFM and early-stance peak KAM and KAM impulse among high-functioning individuals with chronic unilateral ACLD knees. There was a low prevalence of varus thrust among high-functioning individuals with chronic unilateral ACLD knees.

Accurate determination of post-operative 3D component positioning in total knee arthroplasty: the AURORA protocol.

BACKGROUND: Successful component alignment is a major metric of success in total knee arthroplasty. Component translational placement, however, is less well reported despite being shown to affect patient outcomes. CT scans and planar X-rays are routinely used to report alignment but do not report measurements as precisely or accurately as modern navigation systems can deliver, or with reference to the pre-operative anatomy. METHODS: A method is presented here that utilises a CT scan obtained for pre-operative planning and a post-operative CT scan for analysis to recreate a computation model of the knee with patient-specific axes. This model is then used to determine the post-operative component position in 3D space. RESULTS: Two subjects were investigated for reproducibility producing 12 sets of results. The maximum error using this technique was 0.9° ± 0.6° in rotation and 0.5 mm ± 0.3 mm in translation. Eleven subjects were investigated for reliability producing 22 sets of results. The intra-class correlation coefficient for each of the three axes of rotation and three primary resection planes was > 0.93 indicating excellent reliability. CONCLUSIONS: Routine use of this analysis will allow surgeons and engineers to better understand the effect of component alignment as well as the placement on outcome.

Inpatient rehabilitation did not positively affect 6-month patient-reported outcomes after hip or knee arthroplasty.

BACKGROUND: The aim of this study was to compare patient-reported outcomes 6 months after hip or knee arthroplasty in subjects who were discharged to home compared to those who attended inpatient rehabilitation. METHODS: Seven hundred and forty-eight consecutive total hip or knee replacement patients were identified from a prospective database. Preoperative and 6-month post-operative patient-reported outcome measures were recorded. Forty-four patients discharged directly to home were cohort matched by age, gender, procedure and surgeon to 44 patients from the cohort who received inpatient care. Patient outcomes were compared using SPSS version 24 software. RESULTS: Both cohorts saw significant improvements from baseline at 6 months. Median length of rehabilitation for the inpatient group was 7 days (4-16 days). There was no significant difference between the groups based on patient-reported outcomes. There was a clinically significant difference (P = 0.047) in the body mass index of the Home Group (mean = 27) to Rehab Group (mean = 29). CONCLUSION: Our study has shown that inpatient rehabilitation after hip or knee arthroplasty did not positively affect 6-month patient-reported satisfaction, expectation, pain, quality of life, activities of daily living scores, when compared with subjects who were discharged direct to home. A significant average saving of $5600 per patient with the use of home discharge is a promising avenue for health cost reduction, and health resource distribution.

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 THA were 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 < .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 = .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 = .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.

Patient-Specific Simulated Dynamics After Total Knee Arthroplasty Correlate With Patient-Reported Outcomes.

BACKGROUND: Component alignment variation following total knee arthroplasty (TKA) does not fully explain the instance of long-term postoperative pain. Joint dynamics following TKA vary with component alignment and patient-specific musculoskeletal anatomy. Computational simulations allow joint dynamics outcomes to be studied across populations. This study aims to determine if simulated postoperative TKA joint dynamics correlate with patient-reported outcomes. METHODS: Landmarking and 3D registration of implants was performed on 96 segmented postoperative computed tomography scans of TKAs. A cadaver rig-validated platform for generating patient-specific simulation of deep knee bend kinematics was run for each patient. Resultant dynamic outcomes were correlated with a 12-month postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS). A Classification and Regression Tree (CART) was used for determining nonlinear relationships. RESULTS: Nonlinear relationships between the KOOS pain score and rollback and dynamic coronal alignment were found to be significant. Combining a dynamic coronal angular change from extension to full flexion between 0° and 4° varus (long leg axis) and measured rollback of no more than 6 mm without rollforward formed a "kinematic safe zone" of outcomes in which the postoperative KOOS score is 10.5 points higher (P = .013). CONCLUSION: The study showed statistically significant correlations between kinematic factors in a simulation of postoperative TKA and postoperative KOOS scores. The presence of a dynamic safe zone in the data suggests a potential optimal target for any given individual patient's joint dynamics and the opportunity to preoperatively determine a patient-specific alignment target to achieve those joint dynamics.

2018 International Olympic Committee Consensus Statement on Prevention, Diagnosis, and Management of Pediatric Anterior Cruciate Ligament Injuries.

In October 2017, the International Olympic Committee hosted an international expert group of physical therapists and orthopaedic surgeons who specialize in treating and researching pediatric anterior cruciate ligament (ACL) injuries. The purpose of this meeting was to provide a comprehensive, evidence-informed summary to support the clinician and help children with ACL injury and their parents/guardians make the best possible decisions. Representatives from the following societies attended: American Orthopaedic Society for Sports Medicine; European Paediatric Orthopaedic Society; European Society for Sports Traumatology, Knee Surgery, and Arthroscopy; International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine; Pediatric Orthopaedic Society of North America; and Sociedad Latinoamericana de Artroscopia, Rodilla, y Deporte. Physical therapists and orthopaedic surgeons with clinical and research experience in the field and an ethics expert with substantial experience in the area of sports injuries also participated. This consensus statement addresses 6 fundamental clinical questions regarding the prevention, diagnosis, and management of pediatric ACL injuries. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision making with children and the potential long-term ramifications of the injury.

Patient Variation Limits Use of Fixed References for Femoral Rotation Component Alignment in Total Knee Arthroplasty.

BACKGROUND: Optimal rotational alignment of the femoral component is a common goal during total knee arthroplasty. The posterior condylar axis (PCA) is thought to be the most reproducible reference in surgery, while the transepicondylar axis (TEA) seems to better approximate the native kinematic flexion axis. This study sought to determine if rules based on patient gender or coronal alignment could allow reliable reproduction of the TEA from the PCA. METHODS: Three-dimensional models based on preoperative computed tomography were made representing a patient's arthritic knee joint. The landmarks were defined and angular relationships determined. RESULTS: The population group of 726 patients contained large anatomic variation. When applying the standard reference rule of 3° external rotation from the PCA, 36.9% of patients would have a rotational target greater than ±2° from their TEA. When applying the mean external rotation of the TEA from the PCA (1.85°) from this population, this proportion dropped to 26.0% of patients. The use of statistically significant gender and coronal alignment relationships to define the femoral rotation did not reduce the proportion of patients in ±2° error. CONCLUSION: This study shows that gender and coronal alignment relationships to the TEA to PCA angle are not clinically significant as a quarter of patients would still have a target for rotation greater than ±2° from the TEA using these relationships. Superior tools for orienting rotational cuts directly to the TEA in surgery or preoperative identification of relevant patient-specific angles might capture the proportion of patients for whom standard reference angles are not appropriate.

Supercritical Carbon Dioxide-Sterilized Bone Allograft in the Treatment of Tunnel Defects in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Histologic Evaluation.

PURPOSE: To examine the histologic properties of supercritical carbon dioxide (sCO2)-sterilized bone allograft for tunnel grafting and determine in vivo graft quality, as well as graft incorporation and remodeling, in 2-stage revision anterior cruciate ligament (ACL) surgery. METHODS: Histologic evaluation was performed in 12 subjects undergoing 2-stage revision ACL reconstruction. In the first stage, the femoral and tibial tunnels were debrided, tunnel dimensions were measured, and tunnels were grafted with sCO2-sterilized bone allograft. In the second stage, revision ACL reconstruction was performed and bone biopsy specimens were taken from the tibia. Tissue, bone, and graft volumes were measured, and histomorphometric analysis was performed. RESULTS: The mean time between the 2 stages was 8.8 months (range, 5.6-21.3 months). In the second stage, bone graft material was easily identified by its necrotic appearance comprising mature lamellar bone devoid of osteocyte nuclei within osteocyte lacunae. In all tissue samples, host-bone apposition of predominantly mature lamellar bone was noted on the surface of graft fragments in keeping with "creeping substitution." In several regions in 3 cases, osteoblastic and osteoclastic activity was evident in keeping with ongoing creeping substitution and remodeling. The mean bone volume over tissue volume was 68% (range, 33%-92%), and the mean graft volume over bone volume was 41% (range, 19%-70%). The mean graft volume (8 cases) harvested at less than 7 months (44%; 95% confidence interval, 31.4%-56.8%) was not significantly different than the mean graft volume (4 cases) harvested at greater than 10 months (34%; 95% confidence interval, 14.3%-54.2%; P = .214). CONCLUSIONS: The sCO2-sterilized bone allograft showed graft incorporation and remodeling through creeping substitution. CLINICAL RELEVANCE: The initial bone apposition and graft fragment bridging appear to provide a strong environment for ACL graft fixation resulting in technically successful 2-stage revision ACL reconstruction.