Nawabi, Danyal H.

Background: Adequate cam resection during hip arthroscopy for femoroacetabular impingement syndrome (FAIS) is necessary to restore femoral head-neck offset while avoiding under- or over-resection. The relationship between the extent of femoroplasty and postoperative patient-reported outcomes remains unclear. Purpose: We sought to answer the following questions: What is the association between the extent of cam femoroplasty resection and postoperative improvements? and is a 5% resection threshold associated with improved outcomes? Methods: We conducted a retrospective review of patients with adequate acetabular coverage who underwent primary hip arthroscopy with femoroplasty between January 2015 and December 2022 at our institution and had preoperative and 1- and/or 2-year postoperative modified Harris hip score (mHHS) and/or International Hip Outcome Tool (iHOT) scores. We included 400 patients (409 hips; ages 14–50 years). Outcomes included score changes and achievement of minimum clinically important difference (MCID) and substantial clinical benefit (SCB). Postoperative Dunn lateral radiographs quantified femoroplasty by resection depth percentage (resection depth/femoral head diameter), proximal resection angle, and postoperative α angle. Hips were classified as under-resection, neutral (0%–5%), or over-resection (>5%), and differences in outcomes were compared between resection groups. Multivariable regression analyses controlled for demographic, radiographic, and surgical variables. Results: Mean resection depth was 4.8%; mean proximal resection angle was 72.6°. No differences were observed in score improvements or MCID/SCB rates between groups with under-resection versus over-resection at 1 or 2 years. Greater resection depth was associated with larger 1-year mHHS and iHOT improvements and independently predicted 1-year iHOT MCID and SCB. Higher proximal resection angle predicted 2-year iHOT MCID. Conclusion: In this retrospective, single-institution cohort study, we found that in patients with FAIS, greater femoroplasty depth was associated with improved 1-year clinical outcomes. Level of Evidence: Level III, retrospective cohort study.

AbstractDeep learning has the potential to be one of the most transformative technologies to impact orthopedic surgery. Substantial innovation in this area has occurred over the past 5 years, but clinically meaningful advancements remain limited by a disconnect between clinical and technical experts. That is, it is likely that few orthopedic surgeons possess both the clinical knowledge necessary to identify orthopedic problems, and the technical knowledge needed to implement deep learning‐based solutions. To maximize the utilization of rapidly advancing technologies derived from deep learning models, orthopedic surgeons should understand the steps needed to design, organize, implement, and evaluate a deep learning project and its workflow. Equipping surgeons with this knowledge is the objective of this three‐part editorial review. Part I described the processes involved in defining the problem, team building, data acquisition, curation, labeling, and establishing the ground truth. Building on that, this review (Part II) provides guidance on pre‐processing and augmenting the data, making use of open‐source libraries/toolkits, and selecting the required hardware to implement the pipeline. Special considerations regarding model training and evaluation unique to deep learning models relative to “shallow” machine learning models are also reviewed. Finally, guidance pertaining to the clinical deployment of deep learning models in the real world is provided. As in Part I, the focus is on applications of deep learning for computer vision and imaging.

Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered. Cite this article: Bone Joint J 2022;104-B(12):1292–1303.

Objective The purpose of this study was to compare the results of a biphasic synthetic scaffold (TruFit, Smith & Nephew) to microfracture for the treatment of knee cartilage defects and identify patient- and lesion-specific factors that influence outcomes. Design Prospectively collected data from 132 patients (mean age, 41.8 years; 69% male) with isolated chondral or osteochondral femoral defects treated with biphasic synthetic scaffolds ( n = 66) or microfracture ( n = 66) were reviewed. Clinical outcomes were evaluated longitudinally over 5 years with the Short Form–36 (SF-36), Activities of Daily Living of the Knee Outcome Survey (KOS-ADL), International Knee Documentation Committee (IKDC), and Marx Activity Scale. Cartilage-sensitive magnetic resonance imaging (MRI) was performed to evaluate osseous integration and cartilage fill in a subgroup of patients. Multivariate regression analysis was used to identify predictors of clinical outcomes within the scaffold group. Results Both groups demonstrated clinically significant improvements in knee clinical scores over 5 years ( P < 0.01). There were no significant differences in KOS-ADL and IKDC scores between groups up to 5 years postoperatively. Marx activity level scores in the microfracture group declined over time, while significant improvements in activity level scores were observed in the scaffold group over 5 years ( P < 0.01). Good-quality tissue fill and cartilage isointensity were more often observed in the scaffold group compared with the microfracture group, particularly with longer time intervals. Increasing age, high body mass index, prior microfracture, and traumatic etiology were predictors for inferior outcomes in the scaffold group. Conclusions Activity level and MRI appearance following treatment of cartilage lesions with the biphasic synthetic scaffold were superior to microfracture over time in this nonrandomized, retrospective comparison.

Background: Quantitative magnetic resonance (qMR) can be used to measure macromolecules in tissues and is a potential method of observing early cartilage changes in the development of posttraumatic osteoarthritis. Hypothesis/Purpose: We hypothesized that specific patient and surgical factors affecting cartilage matrix composition after anterior cruciate ligament (ACL) reconstruction (ACLR) can be detected using T1ρ and T2 relaxation times. Our purpose was to demonstrate this ability in a multicenter feasibility study. Study Design: Case series; Level of evidence, 4. Methods: A total of 54 patients who underwent ACLR underwent bilateral MRI at baseline before surgery and 6 months postoperatively. Operative findings were recorded. T1ρ and T2 relaxation times were calculated for 6 cartilage regions: the medial femur, lateral femur, medial tibia, lateral tibia, patella, and trochlea. A paired t test compared relaxation times at baseline and 6 months, univariate regression identified regions that influenced patient-reported outcome measures, and analysis of covariance was used to determine the surgical factors that resulted in elevated relaxation times at 6 months. Results: The injured knee had significantly prolonged T1ρ and T2 relaxation times in the tibiofemoral compartment at baseline and 6 months but had shorter values in the patellofemoral compartment compared with the uninjured knee. Prolonged T1ρ and T2 times at 6 months were noted for both the injured and uninjured knees. At 6 months, prolongation of T1ρ and T2 times in the tibial region was associated with lower patient-reported outcome measures. ACLR performed within 30 days of injury had significantly shorter T1ρ times in the tibial regions, and lateral meniscal tears treated with repair had significantly shorter T1ρ times than those treated with excision. Conclusion: Prolonged relaxation times in multiple regions demonstrate how the injury affects the entire joint after an ACL tear. Changes observed in the uninjured knee may be caused by increased loading during rehabilitation, especially in the patellofemoral articular cartilage and distal femur. Relaxation times in the tibial regions may be predictive of patient symptoms at 6 months. These same regions are affected by surgical timing as early as 30 days after injury, but this may partially be reflective of the severity of the preoperative injury and the choice of treatment of meniscal tears.

Background: Limited information exists on the clinical use of a synthetic osteochondral scaffold plug for cartilage restoration in the knee. Purpose/Hypothesis: The purpose of this study was to compare the early magnetic resonance imaging (MRI) appearance, including quantitative T2 values, between cartilage defects treated with a scaffold versus a scaffold with platelet-rich plasma (PRP) or bone marrow aspirate concentrate (BMAC). The hypothesis was that the addition of PRP or BMAC would result in an improved cartilage appearance. Study Design: Cohort study; Level of evidence, 3. Methods: Forty-six patients with full-thickness cartilage defects of the femur were surgically treated with a control scaffold (n = 11), scaffold with PRP (n = 23), or scaffold with BMAC (n = 12) and were followed prospectively. Patients underwent MRI with a qualitative assessment and quantitative T2 mapping at 12 months after surgery. An image assessment was performed retrospectively by a blinded musculoskeletal radiologist. The cartilage phase was measured by cartilage fill and quantitative T2 values on MRI. A comparison between groups after cartilage repair was performed. Results: The control scaffold group consisted of 8 male and 3 female patients (mean age, 38 years; mean body mass index [BMI], 25 kg/m 2 ), the PRP group had 15 male and 8 female patients (mean age, 39 years; mean BMI, 26 kg/m 2 ), and the BMAC group consisted of 8 male and 4 female patients (mean age, 36 years; mean BMI, 26 kg/m 2 ). The PRP-treated ( P = .002) and BMAC-treated ( P = .03) scaffolds had superior cartilage fill compared with the control group. With quantitative methods, the PRP group demonstrated a mean T2 value (49.1 ms) that was similar to that of the control scaffold group (42.7 ms; P = .07), but the BMAC group demonstrated a mean T2 value (60.5 ms) closer to that of superficial hyaline cartilage ( P = .01). The stratification of T2 values between the deep and superficial zones was not observed in any of the groups. Conclusion: In this comparative study, patients treated with scaffold implantation augmented with BMAC had improved cartilage maturation with greater fill and mean T2 values closer to that of superficial native hyaline cartilage at 12 months. Further work will determine if this translates into improved clinical outcomes.