Cartilage Surgery Research Articles

Long-Term Outcomes of Arthroscopically Verified Focal Cartilage Lesions in the Knee: A 19-Year Multicenter Follow-up with Patient-Reported Outcomes.

Focal cartilage lesions (FCLs) are frequently found during knee arthroscopies and may impair quality of life (QoL) significantly. Several treatment options with good short-term results are available, but the natural history without any treatment is largely unknown. The aim of this study was to evaluate patient-reported outcome measures (PROMs), the need for subsequent cartilage surgery, and the risk of treatment failure 20 years after diagnosis of an FCL in the knee. Patients undergoing any knee arthroscopy for an FCL between 1999 and 2012 in 6 major Norwegian hospitals were identified. Inclusion criteria were an arthroscopically classified FCL in the knee, patient age of ≥18 years at surgery, and any preoperative PROM. Exclusion criteria were lesions representing knee osteoarthritis or "kissing lesions" at surgery. Demographic data, later knee surgery, and PROMs were collected by questionnaire. Regression models were used to adjust for and evaluate the factors impacting the long-term PROMs and risk factors for treatment failure (defined as knee arthroplasty, osteotomy, or a Knee injury and Osteoarthritis Outcome Score-Quality of Life [KOOS QoL] subscore of <50). Of the 553 eligible patients, 322 evaluated patients (328 knees) were included and analyzed. The mean follow-up was 19.1 years, and the mean age at index FCL surgery was 36.8 years (95% confidence interval [CI], 35.6 to 38.0 years). The patients without knee arthroplasty or osteotomy had significantly better mean PROMs (pain, Lysholm, and KOOS) at the time of final follow-up than preoperatively. At the time of follow-up, 17.7% of the knees had undergone subsequent cartilage surgery. Nearly 50% of the patients had treatment failure, and the main risk factors were a body mass index of ≥25 kg/m2 (odds ratio [OR] for overweight patients, 2.0 [95% CI, 1.1 to 3.6]), >1 FCL (OR, 1.9 [CI, 1.1 to 3.3]), a full-thickness lesion (OR, 2.5 [95% CI, 1.3 to 5.0]), and a lower level of education (OR, 1.8 [95% Cl, 1.1 to 2.8]). Autologous chondrocyte implantation (ACI) was associated with significantly higher KOOS QoL, by 17.5 (95% CI, 3.2 to 31.7) points, and a lower risk of treatment failure compared with no cartilage treatment, microfracture, or mosaicplasty. After a mean follow-up of 19 years, patients with an FCL who did not require a subsequent knee arthroplasty had significantly higher PROM scores than preoperatively. Nonsurgical treatment of FCLs had results equal to those of the surgical FCL treatments except for ACI, which was associated with a better KOOS and lower risk of treatment failure. Full-thickness lesions, >1 FCL, a lower level of education, and a greater BMI were the main risk factors associated with poorer results. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Defining clinically relevant outcome thresholds for pain and function after osteochondral autograft transplantation of the knee.

To define the minimal clinically important difference (MCID) for measures of pain and function at 2, 5 and 10 years after osteochondral autograft transplantations (OATs). Patients undergoing OATs of the knee were identified from a prospectively maintained cartilage surgery registry. Baseline demographic, injury and surgical factors were collected. Patient-reported outcome scores (PROMs) were collected at baseline, 2-, 5- and 10-year follow-up, including the International Knee Documentation Committee (IKDC) score, Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS), Marx activity scale and Visual Analogue Scale (VAS) for pain. The MCIDs were quantified for each metric utilizing a distribution-based method equivalent to one-half the standard deviation of the mean change in outcome score. The percentage of patients achieving MCID as a function of time was assessed. Of 63 consecutive patients who underwent OATs, 47 (74.6%) patients were eligible for follow-up (surgical date before October 2021) and had fully completed preoperative PROMs. A total of 39 patients (83%) were available for a minimum 2-year follow-up, with a mean (±standard deviation) follow-up of 5.8 ± 3.4 years. The MCIDs were determined to be 9.3 for IKDC, 2.5 for Marx, 7.4 for KOS-ADLS and 12.9 for pain. At 2 years, 78.1% of patients achieved MCID for IKDC, 77.8% for Marx, 75% for KOS-ADLS and 57.9% for pain. These results were generally maintained through 10-year follow-ups, with 75% of patients achieving MCID for IKDC, 80% for Marx, 80% for KOS-ADLS and 69.8% for pain. The majority of patients achieved a clinically relevant outcome improvement after OATs of the knee, with results sustained through 10-year follow-up. Patients who experience clinically relevant outcome improvement after OATs in the short term continue to experience sustained benefits at longer-term follow-up. These data provide valuable prognostic information when discussing patient candidacy and the expected trajectory of recovery. Level III.

Management of failed knee cartilage surgery—an international Delphi consensus statement

IntroductionArticular cartilage injuries of the knee are a complex and challenging clinical pathology. ObjectivesThe purpose of this study was to establish consensus statements via a Delphi process on the management of failed knee cartilage surgery. MethodsA consensus process on knee cartilage injuries utilizing a modified Delphi technique was conducted. Seventy-nine surgeons across 17 countries participated in these consensus statements. Eleven questions were generated on the management of failed knee cartilage surgery, with 3 rounds of questionnaires and final voting occurring. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was defined as 100% agreement with a proposed statement. ResultsOf the 11 total questions and consensus statements on the management of failed knee cartilage surgery developed from 3 rounds of voting, 0 achieved unanimous consensus, 10 achieved strong consensus, and 1 achieved consensus. ConclusionsThe statements that achieved strong consensus related to revision cartilage indications, contraindications, lesion size, prior procedures, unipolar/bipolar lesions, and salvage procedures. The statement that did not achieve strong consensus was related to the management of a failed osteochondral autograft/allograft.

Previous cartilage surgery is associated with inferior patient-reported outcomes after knee arthroplasty.

The hypothesis of the present study assumed that a history of focal cartilage lesions would not affect Knee Injury and Osteoarthritis Outcome scores (KOOSs) following knee arthroplasty compared to a matched national cohort of knee arthroplasty patients. Fifty-eight knee arthroplasty patients with previous surgery for focal cartilage lesions (cartilage cohort) were compared to a matched cohort of 116 knee arthroplasty patients from the Norwegian Arthroplasty Register (control group). Age, sex, primary or revision arthroplasty, type of arthroplasty (total, unicondylar or patellofemoral), year of arthroplasty surgery and arthroplasty brand were used as matching criteria. Demographic data and KOOS were obtained through questionnaires. Regression models were employed to adjust for confounding factors. Mean follow-up post knee arthroplasty surgery was 7.6 years (range 1.2-20.3) in the cartilage cohort and 8.1 (range 1.0-20.9) in the control group. The responding patients were at the time of surgery 54.3 versus 59.0 years in the cartilage and control group, respectively. At follow-up the control group demonstrated higher adjusted Knee Injury and Osteoarthritis Outcome subscores than the previous focal cartilage patients with a mean adjusted difference (95% confidence interval in parentheses): Symptoms 8.4 (0.3, 16.4), Pain 11.8 (2.2, 21.4), Activities of daily living (ADL) 9.3 (-1.2, 18.6), Sport and recreation 8.9 (-1.6, 19.4) and Quality of Life (QoL) 10.6 (0.2, 21.1). The control group also demonstrated higher odds of reaching the patient-acceptable symptom state threshold for the Knee Injury and Osteoarthritis Outcome subscores with odds ratio: Symptoms 2.7 (1.2, 6.4), Pain 3.0 (1.3, 7.0), ADL 2.1 (0.9, 4.6) and QoL 2.4 (1.0, 5.5). Previous cartilage surgery was associated with inferior patient-reported outcomes after knee arthroplasty. These patients also exhibited significantly lower odds of reaching the patient-acceptable symptom state threshold for the Knee Injury and Osteoarthritis Outcome subscores. Level III.

WHAT DRIVES INNOVATION AND CHANGE IN ACL SURGERY? AN ANALYSIS OF 14,352 PATIENTS

IntroductionAnterior cruciate ligament reconstruction (ACLr) is the most widely published operation in the orthopaedic literature. Over recent years there has been increased interest in the surgical technique and role of concomitant procedures performed during ACLr. The National Ligament Registry (NLR) collects robust data on ACLr performed in the UK. In this registry analysis we explore trends in ACLr surgery and how they relate to published literature and the growing industry portfolio available to surgeons.MethodsUsing data from the NLR, 14,352 ACLr performed between 2013–2021 were analysed. High impact papers on ACLr were then cross referenced against this data to see if surgical practice was influenced by literature or whether surgical practice dictated publication. Common trends were also compared to key surgical industry portfolios (Arthrex, Smith and Nephew) to see how new technology influenced surgical practice.ResultsThe number of ACLr performed in isolation is decreasing. The number of ACL reconstructions involving meniscal surgery shows an increasing trend since 2013, with 57% of ACLr in 2021 now involving meniscus surgery. The number of ACLr with lateral extra-articular tenodesis (LET) has increased sharply since 2018, preceding the stability trial publication in 2020. Graft preference and size has remained static despite the introduction of new graft harvest and fixation devices. Additional procedures such as other ligament reconstruction and additional cartilage surgery have also remained static over time.ConclusionIn this analysis we looked at surgical trends in ACLr and their relation to literature and industry. Meniscal intervention is increasing, in keeping with the growing level of literature in this area. In the setting of LET, a high impact level 1 study appears to have significantly changed the practice of UK surgeons with a sharp increase in the number of LET procedures being performed. Industry appears to have little influence on the change in surgical trends, suggesting high quality evidence is what drives innovation in ACLr while industry supports rather than influences innovation. It will be interesting to see the impact of the stability 2 study, recent work on the medial structures of the knee and the commissioning of cartilage centres on future trends.

Evidence-based machine learning algorithm to predict failure following cartilage procedures in the knee

IntroductionClinical decision-making is highly based on expert opinion. Machine learning is increasingly used to develop patient-specific risk prediction analysis to improve patient selection prior to surgery. ObjectivesTo develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect variables associated with failure. MethodsAn institutional database was queried for cartilage procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. Four machine learning algorithms were trained and internally validated. ResultsOne thousand and ninety-one patients with a minimum follow-up of 2 years were included and underwent chondroplasty (n = 560; 51%), osteochondral allograft transplantation (n = 306; 28%), microfracture (n = 150; 14%), autologous chondrocyte implantation (n = 39; 4%), or osteochondral autograft transplantation (n = 36; 3%). The Random Forest algorithm was the best-performing algorithm, with an area under the curve of 0.765 and a Brier score of 0.135. The most important features for predicting failure were symptom duration, age, body mass index, lesion grade, and total lesion area. Local Interpretable Model-agnostic Explanations analysis provided patient-specific comparisons for the risk of failure of an individual patient being assigned various types of cartilage procedures. ConclusionsMachine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features in descending order being symptom duration, age, body mass index, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee.

The Unloading Effect of Supramalleolar Versus Sliding Calcaneal Osteotomy for Treatment of Osteochondral Lesions of the Medial Talus: A Biomechanical Study.

In patients with osteochondral lesion, defects of the medial talus, or failed cartilage surgery, a periarticular osteotomy can unload the medial compartment. To compare the effects of supramalleolar osteotomy (SMOT) versus sliding calcaneal osteotomy (SCO) for pressure redistribution and unloading of the medial ankle joint in normal, varus-aligned, and valgus-aligned distal tibiae. Controlled laboratory study. Included were 8 cadaveric lower legs with verified neutral ankle alignment (lateral distal tibial angle [LDTA] = 0°) and hindfoot valgus within normal range (0°-10°). SMOT was performed to modify LDTA between 5° valgus, neutral, and 5° varus. In addition, a 10-mm lateral SCO was performed and tested in each position in random order. Axial loading (700 N) of the tibia was applied with the foot in neutral alignment in a customized testing frame. Pressure distribution in the ankle joint and subtalar joint, center of force, and contact area were recorded using high-resolution Tekscan pressure sensors. At neutral tibial alignment, SCO unloaded the medial joint by a mean of 10% ± 10% or 66 ± 51 N (P = .04) compared with 6% ± 12% or 55 ± 72 N with SMOT to 5° valgus (P = .12). The achieved deload was not significantly different (ns) between techniques. In ankles with 5° varus alignment at baseline, SMOT to correct LDTA to neutral insufficiently addressed pressure redistribution and increased medial load by 6% ± 9% or 34 ± 33 N (ns). LDTA correction to 5° valgus (10° SMOT) unloaded the medial joint by 0.4% ± 14% or 20 ± 75 N (ns) compared with 9% ± 11% or 36 ± 45 N with SCO (ns). SCO was significantly superior to 5° SMOT (P = .017) but not 10° SMOT. The subtalar joint was affected by both SCO and SMOT, where SCO unloaded but SMOT loaded the medial side. SCO reliably unloaded the medial compartment of the ankle joint for a neutral tibial axis. Changes in the LDTA by SMOT did not positively affect load distribution, especially in varus alignment. The subtalar joint was affected by SCO and SMOT in opposite ways, which should be considered in the treatment algorithm. SCO may be considered a reliable option for beneficial load-shifting in ankles with neutral alignment or 5° varus malalignment.

BONE MARROW-DERIVED STEM CELL TRANSPLANTATION FOR OSTEOCHONDRAL DEFECTS OF THE KNEE: A PROSPECTIVE CLINICAL STUDY

AbstractBackgroundAutologous chondrocyte implantation is a NICE approved intervention however it involves the morbidity of two operations, a prolonged rehabilitation and substantial healthcare costs. This study describes a novel, one-step, bone marrow (BM) derived mesenchymal stem cell (MSC) transplantation technique for treating knee osteochondral lesions and presents our prospective clinical study investigating the success of this technique in 206 lesions over a 5 year period.MethodologyThe surgical technique involves harvesting BM from patients’ anterior superior iliac spines, centrifugation to isolate MSCs and seeding into a type 1 collagen scaffold (SyngenitTM Biomatrix). Autologous fibrin glue is used to secure the scaffold into the defect. Inclusion criteria included patients aged 15 – 55 years old with symptomatic osteochondral lesions &gt;1cm2. Exclusion criteria included patients with ligament instability, uncorrected alignment, inflammatory arthropathy and a Body Mass Index &gt;35 kg/m2. Outcome measures included the Modified Cincinnati Knee Rating System (MCKRS), complications and reoperations.ResultsMean MCKR scores showed statistically significant improvements compared to pre-operative scores at 6 months 58.79 ± 3.5 and 1 year postoperatively 63.82 ± 3.93 with further improvements at 2 years and 5 years which did not reach statistical significance. Survival rates were 97.9%, 94% and 93.2% at 1, 2 and 5 years. Multiple regression analysis identified previous cartilage surgery, microfracture and age as factors affecting MCKRS scores (p &lt; 0.029, 0.001 and 0.030, respectively).ConclusionsOne-step BM derived stem cell transplantation demonstrates satisfactory outcomes over a 5 year period.

Infiltration therapy in the context of cartilage surgery.

Guideline-based surgical cartilage therapy for focal cartilage damage offers highly effective possibilities to sustainably reduce patients' complaints and to prevent or at least delay the development of early osteoarthritis. In the knee joint, it has the potential to reduce almost a quarter of the arthroses requiring joint replacement caused by cartilage damage. Biologically effective injection therapies could further improve these results. Based on the currently available literature and preclinical studies, intra- and postoperative injectables may have a positive effect of platelet-rich plasma/fibrin (PRP/PRF) and hyaluronic acid (HA) on cartilage regeneration and, in the case of HA injections, also on the clinical outcome can be assumed. The role of a combination therapy with use of intra-articular corticosteroids is lacking in the absence of adequate study data and cannot be defined yet. With regard to adipose tissue-based cell therapy, the current scientific data do not yet justify any recommendation for its use. Further studies also regarding application intervals, timing and differences in different joints are required.

Correction of Short Nose Using M-shaped Cartilage in Asian Patients: Finite Element Analysis and Recommendations for Surgery.

Using M-shaped cartilage grafts is a new method for the correction of short nose deformity with good effect for Asians. Although the basic approach to M-shaped cartilage surgery is well understood, there is a great deal of uncertainty when plastic surgeons perform the procedure, and still a lack of standard guidance on the specific details. In this study, the authors used finite element analysis to explore and compare postoperative cartilage stability of different fixing methods, different suturing positions, and different sizes of M-shaped cartilage. The authors applied a 0.01 N load to a 1 cm2 area of the nasal tip to simulate nasal tip palpation and compared the maximum deformations of different groups, which were used to make stability judgments. The maximum deformation of the model was the leastwhen the M-shaped cartilage was fixed medially to the septal cartilage and laterally to the outer crura of the lower lateral cartilage. At the same time, the maximum deformation was the least when the M-shaped cartilage was sutured to the middle of the nasal septal cartilage. Besides, the length of M-shaped cartilage was preferably around 30 mm, while its width was not worthy of being overly concerned. For optimal postoperative stability of Asian short nose correction, the M-shaped cartilage should be sutured and fixed medially to the middle of the septal cartilage and laterally to the lateral crura of the lower lateral cartilage, and the length of the M-shaped cartilage should be controlled at around 30 mm. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Evolution of Rehabilitation and Return to Sport Following Cartilage Surgery.

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Both Labral Debridement and Labral Repair Result in >90% Total Hip Arthroplasty-free Survival at 5-Year Follow-Up: An Analysis of the German Cartilage Registry (KnorpelRegister DGOU)

To compare clinical outcome parameters between labral debridement and repair by analyzing the dataset of a multinational registry. The data are based on the hip module of the German Cartilage Registry (KnorpelRegister DGOU). The register included patients designated for cartilage or femoroacetabular impingement surgery (up to July 1, 2021; n= 2725). The assessment consisted of the patient's characteristics, the type of labral treatment, the length of labral therapy, the pathology, the grade of cartilage damage, and the type of performed approach. The clinical outcomes were documented by the international hip outcome tool via an online platform. Separated Kaplan-Meier analyses were used for total hip arthroplasty (THA)-free survival rates. The debridement group (n= 673) showed a mean score increase of 21.9 ± 25.3 points. The repair group (n= 963) had a mean improvement of 21.3 ± 24.6 (P > .05). The 60-month THA-free survival rate was 90% to 93% for both groups (P > .05). A multivariance analysis showed that the grade of cartilage damage was the only independent statistically significant factor (P= .002-.001) influencing patients' outcomes and THA-free survival. Labral debridement and repair led to good and reliable results. However, these results should not be interpreted with the conclusion that the cheaper and technically easier labral debridement is the recommended treatment due to comparable results in the present study. The clinical outcome and the THA-free survival seemed to be more influenced by the grade of cartilage damage. Level III, retrospective comparative therapeutic trial.

Surgical Management of Failed Articular Cartilage Surgery in the Knee.

Failure rates of cartilage restoration surgery range from 14% to 43%. When failure of prior cartilage restoration surgery is suspected, a thorough clinical workup should be performed to assess the timing and duration of symptoms. Attention should be paid to patient risk factors such as age, body mass index, and smoking status. Concomitant pathology such as malalignment, ligament insufficiency, and meniscus status must be evaluated before revision surgery. As outlined in our treatment algorithm, the size/location of the lesion and the type of primary procedure will guide planning for revision procedures. [Orthopedics. 2023;46(5):262-272.].

The Long-Term Risk of Knee Arthroplasty in Patients with Arthroscopically Verified Focal Cartilage Lesions: A Linkage Study with the Norwegian Arthroplasty Register, 1999 to 2020.

Focal cartilage lesions are common in the knee. The risk of later ipsilateral knee arthroplasty remains unknown. The purposes of the present study were to evaluate the long-term cumulative risk of knee arthroplasty after arthroscopic identification of focal cartilage lesions in the knee, to investigate the risk factors for subsequent knee arthroplasty, and to estimate the subsequent cumulative risk of knee arthroplasty compared with that in the general population. Patients who had undergone surgical treatment of focal cartilage lesions at 6 major Norwegian hospitals between 1999 and 2012 were identified. The inclusion criteria were an arthroscopically classified focal cartilage lesion in the knee, an age of ≥18 years at the time of surgery, and available preoperative patient-reported outcomes (PROMs). The exclusion criteria were osteoarthritis or "kissing lesions" at the time of surgery. Demographic data, later knee surgery, and PROMs were collected with use of a questionnaire. A Cox regression model was used to adjust for and investigate the impact of risk factors, and Kaplan-Meier analysis was performed to estimate cumulative risk. The risk of knee arthroplasty in the present cohort was compared with that in the age-matched general Norwegian population. Of the 516 patients who were eligible, 322 patients (328 knees) consented to participate. The mean age at the time of the index procedure was 36.8 years, and the mean duration of follow-up was 19.8 years. The 20-year cumulative risk of knee arthroplasty in the cartilage cohort was 19.1% (95% CI, 14.6% to 23.6%). Variables that had an impact on the risk of knee arthroplasty included an ICRS grade of 3 to 4 (hazard ratio [HR], 3.1; 95% CI, 1.1 to 8.7), an age of ≥40 years at time of cartilage surgery (HR, 3.7; 95% CI, 1.8 to 7.7), a BMI of 25 to 29 kg/m2 (HR, 3.9; 95% CI, 1.7 to 9.0), a BMI of ≥30 kg/m2 (HR, 5.9; 95% CI, 2.4 to 14.3) at the time of follow-up, autologous chondrocyte implantation (ACI) at the time of the index procedure (HR, 3.4; 95% CI, 1.0 to 11.4), >1 focal cartilage lesion (HR, 2.1; 95% CI, 1.1 to 3.7), and a high preoperative visual analog scale (VAS) score for pain at the time of the index procedure (HR, 1.1; 95% CI, 1.0 to 1.1). The risk ratio of later knee arthroplasty in the cartilage cohort as compared with the age-matched general Norwegian population was 415.7 (95% CI, 168.8 to 1,023.5) in the 30 to 39-year age group. In the present study, we found that the 20-year cumulative risk of knee arthroplasty after a focal cartilage lesion in the knee was 19%. Deep lesions, higher age at the time of cartilage surgery, high BMI at the time of follow-up, ACI, and >1 cartilage lesion were associated with a higher risk of knee arthroplasty. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Combined Autologous Adductor Magnus and Partial Quadriceps Tendon Technique for Medial Patellofemoral Ligament Reconstruction and Cellularized Scaffold Implantation of the Patella

There are many studies in the literature on the use of adductor magnus and quadriceps tendons in primary or revision surgery of patellofemoral instability in skeletally immature patients. In this Technical Note, the combination of both tendons is presented with cellularized scaffold implantation cartilage surgery in the patella.

Paper 19: Evidence-Based Machine Learning Algorithm to Predict Failure Following Cartilage Preservation Procedures in the Knee

Objectives: To develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect the most valuable variables associated with failure. Methods: A single institution prospectively collected database of cartilage procedures was queried for procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery and/or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. The dataset was randomly divided into training (70%) and independent testing (30%) sets. Four machine learning algorithms were trained and internally validated. Algorithm performance was assessed using area under curve (AUC) and the Brier score. Local Interpretable Model-agnostic Explanations (LIME) was utilized to assess the optimized algorithm fidelity. Results: A total of 1091 patients who underwent surgical procedures addressing cartilage defects in the knee with a minimum of 2-years of follow-up were included. The mean follow-up was 3.5 ± 2.8 years. The mean age was 40.5 ± 15 years. There were 205 (18.8%) patients who failed at final follow-up. The Random Forest algorithm was found to be the best performing algorithm, with an AUC of 0.765 and a Brier score of 0.135. The 10 most important features for predicting failure following surgical procedures addressing cartilage defects of the knee were: symptom duration, age, body mass index (BMI), lesion grade, total lesion area (sum of all lesion areas), number of previous surgeries, number of lesions in the knee, gender, athletic level, and traumatic etiology. LIME analysis allowed for assessment of the optimized algorithm fidelity, as well as provided a patient-specific comparison for the risk of failure of an individual patient being assigned various types of cartilage procedures. Conclusions: Machine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features being symptom duration, age, BMI, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee. Integrated human and machine learning decision-making may improve patient selection and bring about the new era of patient-tailored evidence-based clinical care. [Table: see text][Table: see text][Figure: see text][Figure: see text]

An Instant Underwater Tissue Adhesive Composed of Catechin-Chondroitin Sulfate and Cholesterol-Polyethyleneimine.

Due to the safety issue and poor underwater adhesion of current commercially available bioadhesives, they are hard to apply to in vivo physiological environments and more diverse medical use conditions. In this study, a novel and facile bioadhesive for underwater medical applications are designed based on the coacervation of electrostatic interactions and hydrophobic interactions, with the introduction of catechin as a provider of catechol moieties for adhesion to surrounding tissues. The orange-colored bio-adhesive, named PcC, is generated within seconds by mixing catechin-modified chondroitin sulfate and cholesterol chloroformate-modified polyethyleneimine with agitation. In vitro mechanical measurements prove that this novel PcC bio-adhesive is superior in underwater adhesion performance when applied to cartilage. Animal experiments in a rat mastectomy model and rat cartilage graft implantation model demonstrate its potential for diverse medical purposes, such as closing surgical incisions, reducing the formation of seroma, and tissue adhesive applied in orthopedic or cartilage surgery.

Survivorship and Reoperation of 324 Consecutive Isolated or Combined Arthroscopic Meniscal Allograft Transplants Using Soft Tissue Fixation

Background: Meniscal allograft transplant (MAT) is an effective treatment for relieving symptoms and improving knee function in patients who experience symptomatic unicompartmental knee pain after a previous meniscectomy. However, the literature contains a paucity of studies assessing the survival rate and prognostic factors of soft tissue MAT. Purpose: To report the survivorship of a large, single-center cohort of consecutive patients treated with arthroscopic MAT using soft tissue technique and to investigate variables that could potentially influence failures and outcomes. Study design: Case series; Level of evidence, 4. Methods: Consecutive MAT procedures totaling 364 performed in a single institution between June 2004 and April 2019 were screened and assessed for eligibility. Subjective clinical scores (Lysholm score, Tegner activity scale, and visual analog score) were collected preoperatively and at 2, 5, 7, and 10 years of follow-up. Two survival analyses were performed using Kaplan-Meier curves, with surgical failure (defined as any graft revision) and clinical failure (defined as a Lysholm score <65 points) used as endpoints. Univariate analyses were performed using reoperations, surgical failure, clinical failure, and different demographic and surgical characteristics as endpoints. Results: A total of 324 consecutive patients were evaluated at a mean follow-up 5.7 ± 3.0 years. Of these, 189 (58%) underwent an associated surgical procedure. A total of 22 patients (6.8%) were considered to have experienced surgical failure, and no predictors of surgical failure were identified based on the relevant variables. When all patients were considered, a significant improvement in all of the patient-reported outcome measures was present between the preoperative assessment and the last follow-up (P < .001), with no significant decrease over time. Moreover, 70 (21.6%) patients were considered to have experienced clinical failure; the need for concurrent cartilage procedures (odds ratio, 0.16; P = .001) and anterior cruciate ligament (ACL) reconstruction (odds ratio, 0.40; P = .059) were predictors of failure. Finally, a lower survival rate was reported in female patients compared with male patients (49% vs 69%, respectively; P = .007) and in patients who required cartilage surgery (P = .014). In particular, patients who required cartilage surgery showed nearly half the survival rate compared with those with required no cartilage procedures at 10-year follow-up (36.4% vs 71%, respectively; P = .029). Conclusion: Female sex and the need to combine MAT with a cartilage procedure or ACL reconstruction could result in an increased rate of clinical failure at midterm follow-up.

Adolescent elbow osteochondral lesions following prior elbow fracture pinning.

Pinning of pediatric elbow fractures has been shown to be a safe procedure with a low complication profile. This study identified patients who underwent cartilage surgery for elbow osteochondral lesions or osteochondritis dissecans who had prior ipsilateral elbow pinning. Records of patients who underwent ipsilateral cartilage surgery for osteochondritis dissecans and prior percutaneous pinning for elbow fractures were identified. Demographics were compiled and the clinical, radiographic, and surgical results were tabulated for patients with at least 1-year of follow-up from initial presentation. In total, 6/52 (11.5%) pediatric patients from 2012 to 2021 who underwent isolated elbow osteochondritis dissecans surgery (mean age at surgery 13.4 ± 1.5 years) had a history of ipsilateral elbow pinning (mean age at surgery 6.9 ± 2.4 years). Of these, five had a history of a supracondylar fracture while one patient sustained a lateral condyle fracture. Overall, three of six patients had mechanical symptoms at presentation and three had abnormal radiographs. All patients underwent pre-operative magnetic resonance imaging and the five patients with an osteochondritis dissecans lesion <1cm2 underwent arthroscopy and microfracture while one with a 4-cm2 lesion underwent open osteochondral allograft transfer. All patients demonstrated improved motion at final follow-up and all patients were able to return to full desired activity following surgery. This study demonstrates that the history of elbow fracture pinning may predispose patients to future elbow chondral injuries in adolescence. Although patients appear to do well following consequent osteochondritis dissecans surgery, patients and parents may be advised of possible association of elbow pinning and elbow osteochondral lesions. III, case-control study.

The Effect of Lesion Size on Pain and Function in Patients Scheduled for Cartilage Surgery of the Knee.

ObjectiveDespite an increased interest in treatment options for cartilage lesions of the knee, the relationship between lesion characteristics and the symptoms they elicit is not well understood. We evaluated the relationship between lesion characteristics and the patient-reported outcome measures (PROMs) and compared this with symptoms reported by patients scheduled for knee ligament reconstruction and knee arthroplasty.DesignPreoperative data, including Lysholm score and The Knee Injury and Osteoarthritis Outcome Score (KOOS), in 90 consecutive patients scheduled for surgery for symptomatic isolated cartilage lesions were prospectively collected.ResultThe patients had a mean age of 33.2 years. There were 62 (69%) males. There was no statistically significant difference in PROMs between patients with cartilage lesions smaller or larger than 2 cm2, except for the KOOS subscale symptoms, with patients with smaller lesions reporting higher scores, 62.8 (95% confidence interval [CI] 58.3-67.3) vs. 51.9 (95% CI 45.5-58.4), P = 0.005. There was a small correlation between lesion size and Lysholm score. However, when adjusted for age, sex, body mass index, and lesion localization, this effect was not statistically significant. The International Cartilage Regeneration & Joint Preservation Society grade did not affect preoperative PROMs. Cartilage patients reported worse preoperative symptoms than patients scheduled for knee ligament reconstruction, and approaching the symptoms reported by patients scheduled for knee arthroplasty.ConclusionThe size, depth, and location of cartilage lesions have little impact on the symptoms experienced by the patients. Cartilage patients have comparable symptoms to patients scheduled for knee arthroplasty.