Purpose
Optimal surgical treatment of chondral defects in an athletic population remains highly controversial and has yet to be determined. The purpose of this review was to (1) report data on return ...to sport and (2) compare activity and functional outcome measures following various cartilage restoration techniques.
Methods
A comprehensive review was performed for studies with return-to-sport outcomes after microfracture (MFX), osteochondral autograft transfer (OAT), osteochondral allograft transplantation (OCA), and autologous chondrocyte implantation (ACI). All studies containing return-to-sport participation with minimum 2-year post-operative activity-based outcomes were included. A meta-analysis comparing rate of return to sport between each surgical intervention was conducted using a random-effects model.
Results
Forty-four studies met inclusion criteria (18 Level I/II, 26 Level III/IV). In total, 2549 patients were included (1756 M, 793 F) with an average age of 35 years and follow-up of 47 months. Return to sport at some level was 76 % overall, with highest rates of return after OAT (93 %), followed by OCA (88 %), ACI (82 %), and MFX (58 %). Osteochondral autograft transfer showed the fastest return to sports (5.2 ± 1.8 months) compared to 9.1 ± 2.2 months for MFX, 9.6 ± 3.0 months for OCA and 11.8 ± 3.8 months for ACI (
P
< 0.001). A meta-regression was conducted due to heterogeneity in preoperative factors such as patient age, lesion size, and preoperative Tegner score. None of these factors were found to be significant determinants for rate of return to sport.
Conclusion
In conclusion, in this meta-analysis of 2549 athletes, cartilage restoration surgery had a 76 % return to sport at mid-term follow-up. Osteochondral autograft transfer offered a faster recovery and appeared to have a higher rate of return to preinjury athletics, but heterogeneity in lesion size, athlete age, and concomitant surgical procedures are important factors to consider when assessing individual athletes. This study reports on the rate of return to sport in athletes undergoing various procedures for symptomatic chondral defects.
Level of evidence
IV.
Background
Bone-patellar tendon-bone (bone-tendon-bone) and four-strand hamstring tendon grafts (hamstring) are the most commonly utilized autografts for primary anterior cruciate ligament (ACL) ...reconstruction. Existing clinical trials, registry studies, and meta-analyses offer conflicting opinions regarding the most favorable graft choice.
Questions/purposes
Which graft type for ACL reconstruction (bone-tendon-bone or hamstring) has a higher risk of (1) graft rupture and/or (2) graft laxity?
Methods
We performed a meta-analysis of randomized controlled trials (RCTs), prospective cohort studies, and high-quality national registry studies to compare the outcomes of primary ACL reconstruction with bone-tendon-bone autograft or hamstring autograft. Studies that compared these graft types were identified through a comprehensive search of electronic databases (PubMed, MEDLINE, EMBASE, and the Cochrane Library). Two independent reviewers utilized the Jadad scale for RCT study quality and the Modified Coleman Methodology Score for prospective comparative and registry study quality. The included studies were analyzed for the primary outcome measure of graft rupture with or without revision ACL surgery. In surviving grafts, secondary outcomes of graft laxity were quantified by KT1000/2000™ testing, a positive pivot shift test, and a positive Lachman test. Meta-analysis was performed with Review Manager. A total of 47,613 ACL reconstructions (39,768 bone-tendon-bone and 7845 hamstring) from 14 RCTs, 10 prospective comparative studies, and one high-quality national registry study were included in this meta-analysis. Mean age was 28 years in both groups. Sixty-three percent of patients in the bone-tendon-bone cohort were men versus 57% of patients in the hamstring cohort. Mean followup was 68 ± 55 months.
Results
Two hundred twelve of 7560 (2.80%) bone-tendon-bone grafts ruptured compared with 1123 of 39,510 (2.84%) in the hamstring group (odds ratio = 0.83, 95% confidence interval, 0.72-0.96; p = 0.01). The number needed to treat analysis found that 235 patients would need to be treated with a bone-tendon-bone graft over a hamstring tendon graft to prevent one graft rupture. Instrumented laxity analysis showed that 22% (318 of 1433) of patients in the bone-tendon-bone group had laxity compared with 18% (869 of 4783) in the hamstring tendon group (odds ratio = 0.86; p = 0.16). Pivot shift analysis showed a positive pivot shift in 19% (291 of 1508) of the bone-tendon-bone group compared with 17% (844 of 5062) in the hamstring group (odds ratio = 0.89; p = 0.51). Lachman testing showed a positive Lachman in 25% (71 of 280) of patients receiving bone-tendon-bone grafts compared with 25% (73 of 288) in the hamstring group (odds ratio = 0.96; p = 0.84).
Conclusions
In this meta-analysis of short- to mid-term followup after primary ACL reconstruction, hamstring autografts failed at a higher rate than bone-tendon-bone autografts. However, failure rates were low in each group, the difference observed was small, and we observed few differences between graft types in terms of laxity. Both graft types remain viable options for primary ACL reconstruction, and the difference in failure rate should be one part of a larger conversation with each individual patient about graft selection that should also include potential differences in donor site morbidity, complication rates, and patient-reported outcome measures. Continued prospective collection of patient data will be important going forward as we attempt to further characterize the potential differences in outcomes attributable to graft selection.
Level of Evidence
Level III, therapeutic study.
Deep learning has emerged as a powerful approach to constructing imaging signatures of normal brain ageing as well as of various neuropathological processes associated with brain diseases. In ...particular, MRI-derived brain age has been used as a comprehensive biomarker of brain health that can identify both advanced and resilient ageing individuals via deviations from typical brain ageing. Imaging signatures of various brain diseases, including schizophrenia and Alzheimer's disease, have also been identified using machine learning. Prior efforts to derive these indices have been hampered by the need for sophisticated and not easily reproducible processing steps, by insufficiently powered or diversified samples from which typical brain ageing trajectories were derived, and by limited reproducibility across populations and MRI scanners. Herein, we develop and test a sophisticated deep brain network (DeepBrainNet) using a large (n = 11 729) set of MRI scans from a highly diversified cohort spanning different studies, scanners, ages and geographic locations around the world. Tests using both cross-validation and a separate replication cohort of 2739 individuals indicate that DeepBrainNet obtains robust brain-age estimates from these diverse datasets without the need for specialized image data preparation and processing. Furthermore, we show evidence that moderately fit brain ageing models may provide brain age estimates that are most discriminant of individuals with pathologies. This is not unexpected as tightly-fitting brain age models naturally produce brain-age estimates that offer little information beyond age, and loosely fitting models may contain a lot of noise. Our results offer some experimental evidence against commonly pursued tightly-fitting models. We show that the moderately fitting brain age models obtain significantly higher differentiation compared to tightly-fitting models in two of the four disease groups tested. Critically, we demonstrate that leveraging DeepBrainNet, along with transfer learning, allows us to construct more accurate classifiers of several brain diseases, compared to directly training classifiers on patient versus healthy control datasets or using common imaging databases such as ImageNet. We, therefore, derive a domain-specific deep network likely to reduce the need for application-specific adaptation and tuning of generic deep learning networks. We made the DeepBrainNet model freely available to the community for MRI-based evaluation of brain health in the general population and over the lifespan.
Introduction
Relationships between brain atrophy patterns of typical aging and Alzheimer's disease (AD), white matter disease, cognition, and AD neuropathology were investigated via machine learning ...in a large harmonized magnetic resonance imaging database (11 studies; 10,216 subjects).
Methods
Three brain signatures were calculated: Brain‐age, AD‐like neurodegeneration, and white matter hyperintensities (WMHs). Brain Charts measured and displayed the relationships of these signatures to cognition and molecular biomarkers of AD.
Results
WMHs were associated with advanced brain aging, AD‐like atrophy, poorer cognition, and AD neuropathology in mild cognitive impairment (MCI)/AD and cognitively normal (CN) subjects. High WMH volume was associated with brain aging and cognitive decline occurring in an ≈10‐year period in CN subjects. WMHs were associated with doubling the likelihood of amyloid beta (Aβ) positivity after age 65. Brain aging, AD‐like atrophy, and WMHs were better predictors of cognition than chronological age in MCI/AD.
Discussion
A Brain Chart quantifying brain‐aging trajectories was established, enabling the systematic evaluation of individuals’ brain‐aging patterns relative to this large consortium.
As medical imaging enters its information era and presents rapidly increasing needs for big data analytics, robust pooling and harmonization of imaging data across diverse cohorts with varying ...acquisition protocols have become critical. We describe a comprehensive effort that merges and harmonizes a large-scale dataset of 10,477 structural brain MRI scans from participants without a known neurological or psychiatric disorder from 18 different studies that represent geographic diversity. We use this dataset and multi-atlas-based image processing methods to obtain a hierarchical partition of the brain from larger anatomical regions to individual cortical and deep structures and derive age trends of brain structure through the lifespan (3–96 years old). Critically, we present and validate a methodology for harmonizing this pooled dataset in the presence of nonlinear age trends. We provide a web-based visualization interface to generate and present the resulting age trends, enabling future studies of brain structure to compare their data with this reference of brain development and aging, and to examine deviations from ranges, potentially related to disease.
•Multi-site harmonization method that pools volumetric data from 18 studies, controlling for nonlinear age effects.•Resulting dataset covers ages 3 to 96 and used to derive age trends of brain structure through the lifespan.•Interactive visualization tool provided for exploring age trends and comparing new data.
Purpose
Medial meniscus posterior root tears (MMPRTs) are a significant source of pain and dysfunction, but little is known about the natural history and outcome and for non-operative management of ...these lesions. The purpose of this study was to evaluate (1) the mid-term clinical and radiographic outcomes of non-operative treatment of MMPRTs and (2) risk factors for worse outcomes.
Methods
A retrospective review was performed for patients with symptomatic, unrepaired MMPRTs and a minimum 2-year follow-up for IKDC and Tegner outcome scores. Baseline and final radiographs were reviewed and graded according to Kellgren–Lawrence scores. Baseline MRIs were reviewed for the presence of meniscal extrusion, subchondral oedema, and insufficiency fractures. Failure was defined as conversion to arthroplasty or severely abnormal patient subjective IKDC score.
Results
Fifty-two patients (21M:31F) with a mean age of 58 ± 10 years were diagnosed with symptomatic MMPRTs clinically and confirmed by MRI and followed for a mean of 62 ± 30 months. Sixteen patients (31 %) underwent total knee arthroplasty at a mean of 30 ± 32 months after diagnosis with higher Kellgren–Lawrence grades associated with increased rates of arthroplasty (
p
= 0.01). Mean IKDC scores for the remaining patients were 61.2 ± 21 with significantly lower scores in females compared to males (75 ± 12 vs. 49 ± 20;
p
= 0.03). Mean Kellgren–Lawrence grades and rates of arthritis progressed over time on radiographs (1.5 ± 0.7 vs. 2.4 ± 1.0;
p
< 0.001 and 78 % vs. 51 %;
p
= 0.01). Overall, 87 % of patients failed non-operative treatment.
Conclusions
Non-operative treatment of medial meniscus posterior horn root tears is associated with poor clinical outcome, worsening arthritis, and a relatively high rate of arthroplasty at 5-year follow-up. Female gender was associated with lower subjective scores and higher rate of arthroplasty. The current study provides a natural history benchmark for clinical outcomes that can be expected in patients with medial meniscus posterior horn root tears undergoing non-operative treatment and helps in counselling patients with these types of injuries.
Level of evidence
IV.
Purpose
Medial meniscus posterior root tears (MMPRTs) are recognized as a source of pain and dysfunction, but treatment options remain a challenge. The purpose of the study was to determine (1) the ...efficacy of partial meniscectomy to treat MMPRTs compared to a matched group of non-operatively treated MMPRTs, and (2) risk factors for worse clinical and radiographic outcome.
Methods
This retrospective comparative study was performed to include patients with complete, isolated MMPRTs with documented clinical symptoms and were treated with arthroscopic partial meniscectomy (PMM) and a minimum 2-year follow-up. These patients were then matched by age, gender, and BMI to patients with the same diagnosis who were treated non-operatively. Clinical and radiographic outcomes were compared between the two groups. Analysis was performed to determine risk factors for worse clinical and radiographic outcome in the PMM group alone.
Results
Overall, 52 patients were included in the study. Twenty-six patients (9M:17F) with a mean age of 55 ± 9 and a mean BMI of 32.8 ± 5.3 were treated with PMM and followed for 5.5 ± 2.0 years (range 2.3–9.3 years). In the PMM group, final median Tegner score was 3, mean IKDC score was 67.8 ± 20, and more patients had grade II or higher arthritis at final follow-up than baseline (91.3 vs. 36%,
p
< 0.01). Overall, 14 of the 26 patients (54%) treated operatively progressed to total knee arthroplasty at a mean of 54.3 months. There was no significant difference in final Tegner scores, IKDC, K-L grades, progression to arthroplasty, or overall failure rate between the PMM group and non-operative group. Following PMM, female patients had lower final IKDC scores (44.0 ± 2.8 vs. 74.6 ± 16.7,
p
= 0.02) compared to males, as well as a higher rate of arthroplasty (70.6 vs. 20.0%,
p
= 0.009). Higher BMI correlated with lower IKDC scores (
r
= −0.91,
p
= 0.01) and meniscal extrusion was associated with higher rate of arthritis at final follow-up (
p
= 0.02).
Conclusion
Partial meniscectomy for a complete MMPRT provides no benefit in halting arthritic progression. Patients who undergo PMM for MMPRTs still progress to significant arthritis, poor clinical outcomes and a high arthroplasty rate (54%) at over 5-year follow-up. Female gender, increased BMI, and meniscus extrusion were associated with worse outcome.
Study design
Level III.
Purpose
Medial patellofemoral ligament (MPFL) reconstruction and tibial tubercle osteotomy are commonly used to treat recurrent lateral patellar instability, yet there are limited available data on ...return to sport (RTS) following these procedures. The purpose of this study is to evaluate patient factors associated with excellent functional outcomes, including successful RTS, following surgical stabilization including MPFL reconstruction in competitive athletes with recurrent lateral patellar instability.
Methods
Athletes undergoing primary MPFL reconstruction for recurrent lateral instability from 2005 to 2013 were identified at a single institution. Concomitant procedures, such as tibial tubercle osteotomy (TTO), were included. Patient demographic information, including BMI, gender, age, and pre-injury Tegner score, was recorded. In addition, radiographs were reviewed for pre-operative patellar height (Caton–Deschamps index) and trochlear dysplasia (Dejour classification). All patients underwent a standardized rehabilitation/post-operative protocol, with isokinetic strength and functional testing being performed at 6 months post-operatively. Final Tegner scores, RTS status, subjective instability ratings, and Kujala scores were collected at a minimum of 2 years. Chi-squared analysis for categorical variables and Wilcoxon rank-sum analysis for continuous variables were used to determine the relationship between the previously mentioned patient and knee characteristics with isokinetic data, RTS status, or Kujala scores.
Results
Thirty-nine athletes (23 male, 16 female) at a mean age of 17.5 ± 2.9 years (range, 13–26) underwent primary MPFL reconstruction (32 autografts, seven allografts) for recurrent patellar instability with a mean follow-up of 47.0 ± 16.4 months. Sixteen patients (41%) underwent concomitant tibial tubercle osteotomies. Isokinetic data collected at 6 months post-operatively demonstrated mean knee flexion and extension strength deficits of 15.8 ± 10.1% and 21.4 ± 14.3%, respectively, compared to the contralateral leg (
p
< 0.001 for both). Patients who underwent concomitant tibial tubercle osteotomy (
p
= 0.04), males (
p
= 0.01) and those with patella alta (
p
= 0.04) had weaker 6-month isokinetic testing. Thirty-three of the thirty-nine (85%) athletes were able to RTS at a mean of 8.1 ± 3.9 months. Patients undergoing MPFL with concomitant TTO (
p
= 0.02) returned to sport at a slower rate. One patient (3%) reported an episode of recurrent dislocation requiring revision surgery. Kujala and Tegner scores at final follow-up were 91.1 ± 6.3 and 6 (range, 4–9), respectively.
Conclusion
Surgical stabilization including MFPL reconstruction for recurrent lateral patellar instability is an effective procedure for returning athletes to competitive sports. However, strength deficits persist at 6 months after surgery, especially in those undergoing concomitant TTO, which may delay return to sport. Physicians can use these results to counsel patients that return to competitive sports is safe with good clinical outcomes and low rate of recurrence at 4-year follow-up; however, predisposing factors, like a lateralized tibial tubercle, should be addressed if necessary, but athletes should be counselled that a slower recovery and longer return to sport time may be expected.
Level of evidence
IV.
Background
In the medical imaging domain, deep learning‐based methods have yet to see widespread clinical adoption, in part due to limited generalization performance across different imaging devices ...and acquisition protocols. The deviation between estimated brain age and biological age is an established biomarker of brain health and such models may benefit from increased cross‐site generalizability.
Purpose
To develop and evaluate a deep learning‐based image harmonization method to improve cross‐site generalizability of deep learning age prediction.
Study Type
Retrospective.
Population
Eight thousand eight hundred and seventy‐six subjects from six sites. Harmonization models were trained using all subjects. Age prediction models were trained using 2739 subjects from a single site and tested using the remaining 6137 subjects from various other sites.
Field Strength/Sequence
Brain imaging with magnetization prepared rapid acquisition with gradient echo or spoiled gradient echo sequences at 1.5 T and 3 T.
Assessment
StarGAN v2, was used to perform a canonical mapping from diverse datasets to a reference domain to reduce site‐based variation while preserving semantic information. Generalization performance of deep learning age prediction was evaluated using harmonized, histogram matched, and unharmonized data.
Statistical Tests
Mean absolute error (MAE) and Pearson correlation between estimated age and biological age quantified the performance of the age prediction model.
Results
Our results indicated a substantial improvement in age prediction in out‐of‐sample data, with the overall MAE improving from 15.81 (±0.21) years to 11.86 (±0.11) with histogram matching to 7.21 (±0.22) years with generative adversarial network (GAN)‐based harmonization. In the multisite case, across the 5 out‐of‐sample sites, MAE improved from 9.78 (±6.69) years to 7.74 (±3.03) years with histogram normalization to 5.32 (±4.07) years with GAN‐based harmonization.
Data Conclusion
While further research is needed, GAN‐based medical image harmonization appears to be a promising tool for improving cross‐site deep learning generalization.
Level of Evidence
4
Technical Efficacy
Stage 1
Complications after total knee arthroplasty (TKA) are devastating for patients, and surgeons are held accountable in alternative payment models. Optimization of modifiable risk factors has become a ...mainstay in the preoperative period. We sought to evaluate the consequence of failure to optimize key risk factors in a modern cohort of patients who underwent TKA.
The American College of Surgeons National Surgical Quality Improvement Program database was searched to identify patients who underwent TKA in 2017-2018. Patients were considered optimized if they had a body mass index <40kg/m2, had albumin >3.5g/dL, were nonsmokers, and were nondiabetic. Patients were then grouped based on the previous 4 risk factors. Thirty-day readmission, infection, general complications, and mortality were analyzed and compared between the groups.
Overall, 84,315 patients were included in the study. A total of 31.6% of patients were not considered optimized. Body mass index >40kg/m2, albumin <3.5, smoking, and insulin-dependent diabetes were all found to be associated with postoperative infection, readmission, mortality, and complication in general (P < .05). When compared, the nonoptimized group was found to have significantly higher risk of readmission (5 vs 3%), infection (2 vs 1%), general complications (8 vs 5%), and mortality (0.35 vs 0.1%) (all P < .001). Logistic regression showed that those with albumin less than 3.5g/dL had 3.7-fold higher odds of infection and 7.2-fold higher odds of 30-day mortality.
Despite knowledge that modifiable risk factors significantly influence postoperative outcomes, surgeons continue to operate on patients who are not optimized. Among the modifiable risk factors analyzed, hypoalbuminemia appears to be the strongest risk factor for all complications evaluated. Special attention should be paid to preoperative nutritional optimization.
Retrospective cohort study, level IV.
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