Men and women demonstrate comparable rates of failures and reoperations following primary osteochondral allograft transplantation of the knee, but women undergo reoperation sooner.

PURPOSE: To compare the differences between men and women who receive primary osteochondral allograft transplantation of the knee with regard to preoperative disease presentation, failures and reoperations. METHODS: A retrospective review of patients ≥18 years old who underwent primary osteochondral allograft transplantation between 2002 and 2020 by a single surgeon with a minimum of 2-year follow-up was performed. Demographic, preoperative, intraoperative and postoperative data were collected for all included patients. Patients were then assigned to two groups, either male or female, based on their reported sex. Statistical analysis was performed to assess sex-related differences in baseline characteristics, comparative survival analysis for determining survival probabilities, and regression analysis for determining variables associated with subsequent reoperation or failure. RESULTS: Among the 437 patients that were identified, 337 patients (77.1% follow-up, 161 men, 176 women) with a minimum of 2-year follow-up were included in our study. The mean age of included patients was 31.3 ± 9.9 years (range, 18.0-55.9), with a BMI of 26.7 ± 4.4 (range, 19.0-39.0) and a mean follow-up of 5.6 ± 2.6 years (range, 2.0-16.3). Male patients had significantly higher body mass index (BMI) (p ≤ 0.01), were more likely to have lesions on the medial femoral condyle (p = 0.041), and had larger lesions at the medial femoral condyle (p ≤ 0.01) and lateral femoral condyle (p ≤ 0.01). 36.8% of patients experienced subsequent reoperation (59 male, 65 female). Mean time to reoperation was 3.5 ± 2.8 years (range, 0.4-16.3 years) in males and 2.1 ± 1.9 years (range, 0.1-13.5 years) in females. No significant difference was found between the two groups with regard to reoperation rates (n.s.) or survivability free from reoperation (n.s.), but females were found to undergo reoperation sooner (p = 0.028). Sixty-three (18.7%) patients experienced subsequent graft failure (36 male, 27 female). No significant difference was found between the two groups in terms of failure rates, time to failure, survivability free from failure, or mode of failure (n.s. for all). CONCLUSIONS: Despite several differences in baseline demographics and intraoperative variables, no significant differences were found between men and women receiving primary osteochondral allograft transplantation of the knee with regard to failure or reoperation, with the exception that women underwent reoperation sooner. STUDY DESIGN: Retrospective Comparative Cohort Study. LEVEL OF EVIDENCE: Level III.

A Prospective, Randomized, Double-Blind Clinical Trial to Investigate the Efficacy of Autologous Bone Marrow Aspirate Concentrate During Arthroscopic Meniscectomy in Patients With Early Knee Osteoarthritis.

BACKGROUND: Despite being recognized as a safe procedure with minimal reported complications, injecting autologous bone marrow aspirate concentrate (BMAC) as an adjuvant to arthroscopic partial meniscectomy (APM) for symptomatic patients with meniscal tears and concomitant knee osteoarthritis (OA) has not been studied in randomized controlled trials. PURPOSE: To compare patient-reported outcome measure (PROM) scores and radiographic outcomes in symptomatic patients with meniscal tears and concomitant mild knee OA who underwent APM with and without an autologous BMAC injection administered at the time of surgery. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Enrolled patients aged ≥18 years determined to have a symptomatic meniscal tear with concomitant mild knee OA suitable for APM and meeting inclusion and exclusion criteria were randomized into 2 groups: BMAC and control (no BMAC). The primary endpoint of the study was the International Knee Documentation Committee (IKDC) score at 1 year postoperatively. Secondary endpoints included radiographic outcomes (Kellgren-Lawrence grade) at 1 year postoperatively and various PROM scores, including those for the IKDC, Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale, and Veterans RAND 12-Item Health Survey, at 3 months, 6 months, 1 year, and 2 years after meniscectomy. RESULTS: Of the 95 enrolled patients, 83 (87.4%) were included for final analysis. No significant differences were found between the groups with regard to patient characteristics, intraoperative variables, concomitant procedures, preoperative PROM scores, or preoperative radiographic findings. At 1 year postoperatively, the BMAC group failed to demonstrate significantly better IKDC scores (P = .687) or radiographic outcomes (P > .05 for all radiographic measures) compared with the control group. Secondary PROM scores also did not significantly differ between the groups (P > .05 for all PROMs). However, there were higher achievement rates of the minimal clinically important difference for the KOOS Sport (100.0% vs 80.0%, respectively; P = .023) and KOOS Symptoms (92.3% vs 68.0%, respectively; P = .038) at 1 year postoperatively in the BMAC group than in the control group. All PROMs, excluding the VR-12 mental score, showed significant improvements compared with baseline at all postoperative time points for both the BMAC and control groups. CONCLUSION: The addition of an autologous BMAC injection during APM did not result in significant changes in IKDC scores or radiographic outcomes at the 1-year postoperative mark. Secondary PROM scores were generally comparable between the 2 groups, but there was higher minimal clinically important difference achievement for the KOOS Sport and KOOS Symptoms at 1 year postoperatively in the BMAC group. In patients with symptoms consistent with a meniscal tear who had concomitant mild OA, the addition of BMAC to arthroscopic debridement did not affect the outcome. REGISTRATION: NCT02582489 (ClinicalTrials.gov).

Meniscal Allograft Transplantation Is a Powerful Tool for Treating Pain for Properly Indicated Patients, but Ability to Prevent Osteoarthritis Progression Remains Undetermined.

In well indicated patients, MAT survivorship can approach 80-90% at 10 years and 50-60% at 15 years, although these studies have included mostly younger patients (mean ages 25-30). Evidence-based indications for meniscal allograft transplantation (MAT) are symptomatic meniscal deficiency in the absence of uncorrected osteoarthritis and malalignment in the young, active patient. The definition of young and active continues to evolve as demands of an aging population grow, and MAT has been performed with favorable outcomes in those over 40 and even 50 years old. However, MAT is not a solution to prevent arthritic progression, and the results in those with osteoarthritis have been less predictable in nature. No studies to date have demonstrated a definable delay to arthroplasty with the use of MAT as compared to the natural history of osteoarthritis. We recommend a focus on alleviating symptoms in properly indicated patients, as well as consider concomitant procedures that are performed to provide an optimal environment for the MAT, such as realignment in the setting of >5˚ of varus (or valgus) or cartilage repair procedures that have been reproducibly performed by a number of authors to date in combination with MAT.

Anterior Cruciate Ligament Repair Results in Similar Patient-Reported Outcome Measures as Anterior Cruciate Ligament Reconstruction: A Systematic Review of Prospective Comparative Studies.

PURPOSE: To investigate the patient-reported outcomes (PROs), knee stability, and complications in prospective comparative studies of patients undergoing augmented anterior cruciate ligament (ACL) repair compared with anterior cruciate ligament reconstruction (ACLR). METHODS: A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Human clinical studies of Level I-II evidence comparing PROs, knee stability, and complications after ACL repair and reconstruction were included, and a qualitative analysis was performed. Excluded studies included those lacking reporting outcomes, studies that performed open ACLR or repair, studies published before the year 2000, and studies with evidence Levels III-IV. Study quality was assessed using the Cochrane Collaboration's risk of bias tool. RESULTS: Seven Level I-II studies were retained, comprising 190 ACLR and 221 repairs (75 bridge-enhanced ACL repair [BEAR], 49 suture augmentation [SA], and 97 dynamic intraligamentary stabilization [DIS]). At final follow-up, re-rupture rates varied between 0 and 14% (BEAR) versus 0 and 6% (ACLR) and mean side-to-side differences measured using KT-1000 testing ranged from 1.6 to 1.9 mm (BEAR) versus 1.7 to 3.14 mm (ACLR). For DIS versus ACLR, mean anterior tibial translation values at final follow-up were 1.7 mm (DIS) versus 1.4 mm (ACLR), and re-rupture rates ranged from 20.8% to 29% (DIS) versus 17% to 27.2% (ACLR). For SA versus ACLR, the mean side-to-side difference ranged from 0.2 to 0.39 mm (SA) versus 0.33 to 0.4 mm (ALCR), whereas the re-rupture rates were 10% (SA) versus 0% (ACLR). International Knee Documentation Committee, Tegner, Lysholm, and Knee Injury and Osteoarthritis Outcome scores across both cohorts exhibited statistically significant, and comparable improvement, from baseline to final follow-up ranging from 1 to 5 years. CONCLUSIONS: Augmented ACL repair results in similar patient-reported outcome measures in comparison with ACLR. However, augmented ACL repair may be associated with greater rates of failure, given re-rupture rates of up to 14%, 29%, and 10% for BEAR, DIS, and SA, respectively. LEVEL OF EVIDENCE: Level II, systematic review of Level I-II studies.

Comparison of Patient-Reported Outcomes for Immediate Unrestricted Weightbearing Versus Restricted Rehabilitation Protocols After Osteochondral Allograft Transplantation to the Distal Femur.

Background: There is no standardized rehabilitation protocol after osteochondral allograft (OCA) transplantation surgery to the distal femur. The spectrum of recommendations includes restrictions to toe-touch weightbearing (TTWB) for 6 weeks and immediate weightbearing as tolerated (WBAT). Purpose/Hypothesis: The purpose of this study was to compare outcomes for immediate unrestricted WBAT to restricted TTWB after OCA transplantation to the distal femur. It was hypothesized that the immediate WBAT protocol would be noninferior to delayed, restricted TTWB. Study Design: Retrospective cohort study. Methods: A total of 74 patients who underwent press-fit, dowel technique OCA transplantation to the femoral condyle(s) for contained (International Cartilage Repair Society grade 3-4) lesions were identified in the Metrics of Osteochondral Allograft multicenter database: 36 patients (18 women/18 men) who were prescribed TTWB were allocated to the control cohort and 38 patients (21 women/17 men) who were prescribed WBAT were allocated to the test cohort. Baseline characteristics were similar except for larger grafts in test patients (3.4 vs 2.7 cm2; P = .004) and higher body mass index (BMI) in control patients (27.8 vs 24.9 kg/m2; P = .01). Failure rates, final patient-reported outcome (PRO) scores, and PRO score changes from baseline were compared between the cohorts. Multiple regression was used to control for potential confounders and investigate noninferiority using minimal clinically important differences (MCIDs). Results: The mean follow-up was 2 years (range, 1-5 years) in both cohorts. Both cohorts showed significant improvement in all PRO scores, with no significant between-group differences in failure rates, final PRO scores, or PRO changes from baseline. There were 3 cases of failure in each cohort (control cohort: allograft revision [n = 2], debridement [n = 1]; test cohort: chondroplasty [n = 2], conversion to total knee arthroplasty [n = 1]). Regression analysis showed that adjusted differences in final PRO scores based on weightbearing protocol were minor and less than MCIDs when controlling for age, sex, graft size, BMI, and allograft location. Analysis of the MCIDs with respect to the lower bounds of the confidence intervals indicated that WBAT was noninferior to TTWB with a reasonable degree of confidence (range, 84.1%-99.9% confidence). Conclusion: Results indicated that immediate unrestricted WBAT after OCA transplantation to the distal femur was equally safe and effective compared to restricted TTWB.

Osteochondral Allograft Reaming Significantly Affects Chondrocyte Viability.

BACKGROUND: Chondrocyte viability is associated with the clinical success of osteochondral allograft (OCA) transplantation. PURPOSE: To investigate the effect of distal femoral OCA plug harvest and recipient site preparation on regional cell viability using traditional handheld saline irrigation versus saline submersion. STUDY DESIGN: Controlled laboratory study. METHODS: For each of 13 femoral hemicondyles, 4 cartilage samples were harvested: (1) 5-mm control cartilage, (2) 15-mm OCA donor plug harvested with a powered coring reamer and concurrent handheld saline irrigation ("traditional"), (3) 15-mm OCA donor plug harvested while submerged under normal saline ("submerged"), and (4) 5-mm cartilage from the peripheral rim of a recipient socket created with a 15-mm cannulated counterbore reamer to a total depth of 7 mm with concurrent handheld saline irrigation ("recipient"). The 15 mm-diameter plugs were divided into the central 5 mm and the peripheral 5 mm (2 edges) for comparisons. Samples were stained using calcein and ethidium, and live/dead cell percentages were calculated and compared across groups. RESULTS: Compared with the submerged group, the traditional group had significantly lower percentages of live cells across the whole plug (71.54% ± 4.82% vs 61.42% ± 4.98%, respectively; P = .003), at the center of the plug (72.76% ± 5.87% vs 62.30% ± 6.11%, respectively; P = .005), and at the periphery of the plug (70.93% ± 4.51% vs 60.91% ± 4.75%, respectively; P = .003). The traditional group had significantly fewer live cells in all plug regions compared with the control group (77.51% ± 9.23%; P < .0001). There were no significant differences in cell viability between the control and submerged groups (whole: P = .590; center: P = .713; periphery: P = .799). There were no differences between the central and peripheral 5-mm plug regions for the traditional (62.30% ± 6.11% vs 60.91% ± 4.75%, respectively; P = .108) and submerged (72.76% ± 5.87% vs 70.93% ± 4.51%, respectively; P = .061) groups. The recipient group (61.10% ± 5.02%) had significantly lower cell viability compared with the control group (P < .0001) and the periphery of the submerged group (P = .009) but was equivalent to the periphery of the traditional group (P = .990). CONCLUSION: There was a significant amount of chondrocyte death induced by OCA donor plug harvesting using a powered coring reamer with traditional handheld saline irrigation, which was mitigated by harvesting the plug while the allograft was submerged under saline. CLINICAL RELEVANCE: Mitigating this thermally induced damage by harvesting the OCA plug while the allograft was submerged in saline maintained chondrocyte viability throughout the plug and may help to improve the integration and survival of OCAs.

Greater Postoperative Biceps Tendon Migration After Arthroscopic Suprapectoral or Open Subpectoral Biceps Tenodesis Correlates With Lower Patient-Reported Outcome Scores.

PURPOSE: To assess the relation between tendon migration, as measured by radiostereometric analysis, and patient-reported outcome measures (PROMs) after biceps tenodesis (BT); to determine the likelihood of achieving clinically significant outcomes (CSOs) after BT; and to identify factors that impact CSO achievement. METHODS: Patients undergoing arthroscopic suprapectoral or open subpectoral BT at a single, high-volume academic medical center were prospectively enrolled. A tantalum bead sutured to the tenodesis construct was used as a radiopaque marker. Biceps tendon migration was measured on calibrated radiographs at 12 weeks postoperatively. PROMs (Constant-Murley, Single Assessment Numeric Evaluation [SANE], and Patient-Reported Outcomes Measurement Information System-Upper Extremity [PROMIS-UE] scores) were collected preoperatively and at minimum 2-year follow-up. RESULTS: Of 115 patients enrolled, 94 (82%) were included (median age, 52 years; median body mass index, 31.4). At a mean follow-up of 2.9 years, the median Constant-Murley, SANE, and PROMIS-UE scores were 33 (interquartile range [IQR], 26-35), 90 (IQR, 80-99), and 47 (IQR, 42-58), respectively. Median tantalum bead migration was 6.5 mm (IQR, 1.8-13.8 mm). There were significant correlations between migration and Constant-Murley score (r2 = 0.222; ß = -0.554 [95% confidence interval (CI), -1.027 to -0.081]; P = .022), SANE score (r2 = 0.238; ß = -0.198 [95% CI, -0.337 to -0.058]; P = .006), and PROMIS-UE score (r2 = 0.233; ß = -0.406 [95% CI, -0.707 to -0.104]; P = .009). On univariable analysis, higher body mass index was associated with achievement of substantial clinical benefit (unadjusted odds ratio [OR], 1.078 [95% CI, 1.007 to 1.161]; P = .038). Greater bead migration was negatively associated with achievement of the minimal clinically important difference (unadjusted OR, 0.969 [95% CI, 0.943 to 0.993]; P = .014) and patient acceptable symptomatic state (unadjusted OR, 0.965 [95% CI, 0.937 to 0.989]; P = .008) on all 3 instruments. CONCLUSIONS: A 1-cm increase in post-tenodesis biceps tendon migration was associated with a decrease in the Constant-Murley, SANE, and PROMIS-UE scores of 6, 2, and 4 points, respectively, at a mean of 2.9 years after surgery. Most patients achieved CSOs for these PROMs by latest follow-up, and greater biceps tendon construct migration was negatively associated with the likelihood of CSO achievement. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Patient-Specific Distal Femoral Guides Optimize Cartilage Topography Matching in Osteochondral Allograft Transplantations.

BACKGROUND: Osteochondral allograft (OCA) transplantation is an important surgical technique for full-thickness chondral defects in the knee. For patients undergoing this procedure, topography matching between the donor and recipient sites is essential to limit premature wear of the OCA. Currently, there is no standardized process of donor and recipient graft matching. PURPOSE: To evaluate a novel topography matching technique for distal femoral condyle OCA transplantation using 3-dimensional (3D) laser scanning to create 3D-printed patient-specific instrumentation in a human cadaveric model. STUDY DESIGN: Descriptive laboratory study. METHODS: Human cadaveric distal femoral condyles (n = 12) underwent 3D laser scanning. An 18-mm circular osteochondral recipient defect was virtually created on the medial femoral condyle (MFC), and the position and orientation of the best topography-matched osteochondral graft from a paired donor lateral femoral condyle (LFC) were determined using an in silico analysis algorithm minimizing articular step-off distances between the edges of the graft and recipient defect. Distances between the entire surface of the OCA graft and the underneath surface of the MFC were evaluated as surface mismatch. Donor (LFC) and recipient (MFC) 3D-printed patient-specific guides were created based on 3D reconstructions of the scanned condyles. Through use of the guides, OCAs were harvested from the LFC and transplanted to the reamed recipient defect site (MFC). The post-OCA recipient condyles were laser scanned. The 360° articular step-off and cartilage topography mismatch were measured. RESULTS: The mean cartilage step-off and graft surface mismatch for the in silico OCA transplant were 0.073 ± 0.029 mm (range, 0.005-0.113 mm) and 0.166 ± 0.039 mm (range, 0.120-0.243 mm), respectively. Comparatively, the cadaveric specimens postimplant had significantly larger step-off differences (0.173 ± 0.085 mm; range, 0.082-0.399 mm; P = .001) but equivalent graft surface topography matching (0.181 ± 0.080 mm; range, 0.087-0.396 mm; P = .678). All 12 OCA transplants had mean circumferential step-off differences less than a clinically significant cutoff of 0.5 mm. CONCLUSION: These findings suggest that the use of 3D-printed patient-specific guides for OCA transplantation has the ability to reliably optimize cartilage topography matching for LFC to MFC transplantation. This study demonstrated substantially lower step-off values compared with previous orthopaedic literature when also evaluating LFC to MFC transplantation. Using this novel technique in a model performing MFC to MFC transplantation has the potential to yield further enhanced results due to improved radii of curvature matching. CLINICAL RELEVANCE: Topography-matched graft implantation for focal chondral defects of the knee in patients improves surface matching and has the potential to improve long-term outcomes. Efficient selection of the allograft also allows improved availability of the limited allograft sources.

Chondrocyte Response to Fresh Autologous Conditioned Serum Versus Freeze-Dried Allogenic Conditioned Serum.

OBJECTIVE: To investigate the cytokine release profile and histological response of human cartilage after exposure to autologous conditioned serum (ACS) and freeze-dried allogenic conditioned serum (FD-CS). DESIGN: Cartilage explants were collected from 6 patients undergoing total knee arthroplasty. ACS and FD-CS were created from patient serum samples. Cartilage samples were divided into 6 groups: (1) untreated control, (2) ACS, (3) FD-CS, (4) untreated interleukin (IL)-1ß (5 ng/ml), (5) IL-1ß + ACS, and (6) IL-1ß + FD-CS. After 12 days, cartilage samples were analyzed with glycosaminoglycan (GAG) concentration normalized to wet weight while comparing cytokine concentrations, and histological scoring. RESULTS: There was a significant decrease in pathology scoring for ACS (P = 0.0368) and FD-CS (P = 0.0368) in the IL-1ß injury groups compared with the untreated IL-1ß insult group. ACS and FD-CS significantly mitigate the IL-1ß induced increase in basic fibroblast growth factor (bFGF) (P = 0.0009 and P = 0.0002, respectively). FD-CS showed a significant decrease in IL-1ß concentration in the presence of IL-1ß insult compared with the untreated IL-1ß group (P < 0.0001). ACS-treated samples had significantly higher concentration of tumor necrosis factor (TNF)-α independent of IL-1ß when compared with samples not treated with biologics (P = 0.0053). CONCLUSIONS: Explanted osteoarthritic cartilage responds favorably and equivalently to treatment with ACS and FD-CS from a histological perspective. Both ACS and FD-CS were able to mitigate the IL-1ß-induced increases in bFGF and FD-CS lowered IL-1ß concentration while increasing interleukin-1 receptor antagonist (IL-1Ra) concentration. Although the cytokine profile of cartilage tissue explants treated with FD-CS appears to be different than that of ACS, this difference does not seem to affect biologic activity of FD-CS.

The chimera of reaching a universal consensus on platelet-rich plasma treatment for knee osteoarthritis: a review of recent consensus statements and expert opinion.

INTRODUCTION: Osteoarthritis (OA) is a prevalent cause of disability worldwide, affecting millions and posing significant socioeconomic burdens. Various conservative measures like hyaluronic acid (HA) and platelet-rich plasma (PRP) injections aim to manage OA symptoms and delay surgical interventions. Despite the increasing utilization of PRP, consensus on its efficacy remains elusive, reflecting the evolving landscape of OA management. AREAS COVERED: This study reviews guidelines and recommendations on intra-articular PRP injections for OA globally, highlighting divergent perspectives among different medical societies. A comprehensive literature search identified 19 relevant guidelines, indicating a temporal and geographic evolution in attitudes toward PRP use. While some guidelines endorse PRP for mild-to-moderate OA, others express caution due to concerns about product standardization and clinical evidence heterogeneity. EXPERT OPINION: The lack of universal consensus on PRP for OA underscores the complex interplay between clinical evidence, practice patterns, and evolving perspectives. Recent shifts toward endorsing PRP may reflect advancements in preparation techniques and personalized medicine approaches. However, challenges persist, including patient selection and product standardization. Efforts to develop consensus and refine PRP classification systems are essential for guiding clinical practice and advancing OA management.

Sport-specific Differences in Cartilage Treatment.

Articular cartilage defects in the knee are common in athletes who have a variety of loading demands across the knee. Athletes of different sports may have different baseline risk of injury. The most studied sports in terms of prevalence and treatment of cartilage injuries include soccer (football), American football, and basketball. At this time, the authors do not specifically treat patients by their sport; however, return to sports timing may be earlier in sports with fewer demands on the knee based on the rehabilitation protocol. If conservative management is unsuccessful, the authors typically perform a staging arthroscopy with chondroplasty, followed by osteochondral allograft transplantation with possible additional concomitant procedures, such as osteotomies or meniscal transplants. Athletes in a variety of sports and at high levels of competition can successfully return to sports with the appropriate considerations and treatment.

Inlay Scaffold Augmentation of Rotator Cuff Repairs Enhances Histologic Resemblance to Native Enthesis in Animal Studies: A Systematic Review.

PURPOSE: To investigate the outcomes of inlay positioned scaffolds for rotator cuff healing and regeneration of the native enthesis after augmentation of rotator cuff tendon repairs in preclinical studies. METHODS: A literature search was performed using the PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature databases according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Preclinical studies reporting on outcomes after inlay tendon augmentation in rotator cuff repair were included. Preclinical study quality was assessed using an adapted version of the Gold Standard Publication Checklist for animal studies. The level of evidence was defined based on the inclusion of clinical analyses (grade A), biomechanical analyses (grade B), biochemical analyses (grade C), semiquantitative analyses (grade D), and qualitative histologic analyses (grade E). RESULTS: Thirteen preclinical studies met the inclusion criteria. Quality assessment scores ranged from 4 to 8 points, and level-of-evidence grades ranged from B to E. Sheep/ewes were the main animal rotator cuff tear model used (n = 7). Demineralized bone matrix or demineralized cortical bone was the most commonly investigated scaffold (n = 6). Most of the preclinical evidence (n = 10) showed qualitative or quantitative differences regarding histologic, biomechanical, and biochemical outcomes in favor of interpositional scaffold augmentation of cuff repairs in comparison to controls. CONCLUSIONS: Inlay scaffold positioning in preclinical studies has been shown to enhance the healing biology of the enthesis while providing histologic similarities to its native 4-zone configuration. CLINICAL RELEVANCE: Although onlay positioned grafts and scaffolds have shown mixed results in preclinical and early clinical studies, inlay scaffolds may provide enhanced healing and structural support in comparison owing to the ability to integrate with the bone-tendon interface.

Long-Term Clinical and Radiographic Outcomes of Meniscus Allograft Transplant.

PURPOSE OF REVIEW: To reduce pain, improve function and possibly mitigate the risk for development of osteoarthritis in patients with functionally deficient meniscus pathology, meniscal allograft transplantation (MAT) can be used to restore native joint biomechanics and increase knee joint longevity. This review explores the senior author's preferred bridge-in-slot technique and recently published long-term clinical and radiographic outcomes following MAT. RECENT FINDINGS: Recent literature demonstrates MAT to be a safe and largely successful procedure for patients with functional meniscus deficiency. A majority of patients reach established minimal clinically important difference (MCID) values. Graft survivorship is approximately 80% at 10 years, significantly delaying and in some cases, preventing the need for future joint reconstruction procedures in these young patients. Return to sport rates are over 70%, revealing meniscal allografts can withstand high impact activities. Cartilage damage at the time of MAT increases the risk for graft and clinical failure, though this may be mitigated with a concomitant cartilage restoration procedure. Meniscal allograft transplantation can provide a durable and effective long-term solution to meniscal deficiency in symptomatic patients who wish to decrease the risk of symptomatic progression and possibly further osteoarthritis and continue activities of daily life and sports with less pain and more function. By restoring more normal joint biomechanics, MAT can mitigate the potential need for future knee arthroplasty in this young active patient population.

Autologous Minced Repair of Knee Cartilage Is Safely and Effectively Performed Using Arthroscopic Techniques.

Articular cartilage defects in the knee are common and possess limited ability to inherently heal. Many of the surgical management options for cartilage repair that result in a hyaline or hyaline-like chondral surface have donor site morbidity, are resource intensive, are costly, and may require multiple surgeries. Autologous minced cartilage implantation is an encouraging, single-stage technique that can be safely and efficiently performed arthroscopically to address focal chondral defects in the knee. The limited morbidity and cost-effective nature of using autograft tissue has clear advantages, including an ability to treat patients at the time a clinically relevant defect is identified, increased availability of tissue, reduced patient morbidity with the use of an arthroscopic harvest technique, and the production of a hyaline cartilage repair product with active chondrocytes. Clinically, it has been demonstrated to be superior to microfracture. However, mincing technique may compromise cell viability. A recent porcine model investigation demonstrated that arthroscopic cartilage harvest using a shaver, contains a significantly lower median number of viable chondrocytes compared to open scalpel harvest, resulting in reduced proteoglycans, glycosaminoglycans, aggrecan, and COL2A1 expression, a result of fewer viable chondrocytes. The authors suggest that traditional open scalpel harvest results in a superior single-stage autologous minced cartilage transplantation product with more hyaline-like tissue compared to arthroscopic mincing techniques. However, the findings of the study regarding cell viability after arthroscopic harvest are in stark contrast to previous findings, including our prior work. Pending future research, it is our view that an arthroscopic single-stage autologous cartilage transplant is more reproducible, efficient, and of lower morbidity than open harvest, and we and others have shown the arthroscopic technique to be both safe and effective.

A biomechanical study to optimize superior capsular reconstruction operative technique.

Background: The goals of this study were to optimize superior capsular reconstruction by assessing the relative fixation strength of 4 suture anchors; evaluating 3 glenoid neck locations for fixation strength and bone mineral density (BMD); determining if there is a correlation between BMD and fixation strength; and determining which portal sites have optimal access to the posterosuperior and anterosuperior glenoid neck for anchor placement. Methods: Twenty cadaveric specimens were randomized into 4 groups: all-suture anchor (FiberTak), conventional 3.0-mm knotless suture anchor (SutureTak), 3.9-mm knotless PEEK (polyetheretherketone) Corkscrew anchor, and 4.5-mm Bio-Corkscrew anchor. Each specimen was prepared with 3 anchors into the glenoid: an anterosuperior anchor, superior anchor, and posterosuperior anchor. All anchors were inserted into the superior glenoid neck 5 mm from the glenoid rim. A materials testing system performed cyclic testing (250 cycles) followed by load-to-failure testing at 12.5 mm/s. Cyclic elongation, first cycle excursion, maximum load, and stiffness were recorded. Using custom software, BMD was calculated at each anchor location. This software was also used to assess access to the posterosuperior and anterosuperior glenoid neck from standard arthroscopic portal positions. Results: There was no significant difference in cyclic elongation (P = .546), first cycle excursion (P = .476), maximum load (P = .817), or stiffness (P = .309) among glenoid anchor positions. Cyclic elongation was significantly longer in the PEEK Corkscrew group relative to the other implants (P ≤ .002). First cycle excursion was significantly greater in the FiberTak group relative to all other implants (P ≤ .008). For load-to-failure testing, the Bio-Corkscrew group achieved the highest maximum load (P ≤ .001). No other differences in cyclic or failure testing were observed between the groups. No differences in stiffness testing were observed (P = .133). The superior glenoid rim had the greatest BMD (P = .003), but there was no correlation between BMD and cyclic/load outcomes. The posterior portal (80% of specimens) and the anterior portal (60% of specimens) demonstrated the best access to the posterosuperior and anterosuperior glenoid neck, respectively. Conclusion: The 4.5-mm Bio-Corkscrew anchor provided the most robust fixation to the glenoid during superior capsular reconstruction as it demonstrated the strongest maximum load, had minimal elongation, had minimal first cycle excursion, and did not fail during cyclic testing. The superior glenoid neck had the highest BMD; however, there was no correlation between BMD or glenoid anchor location and biomechanical outcomes. The posterior portal and anterior portal provided optimal access to the posterosuperior glenoid neck and anterosuperior glenoid neck, respectively.

The Gut Microbiome and Joint Microbiome Show Alterations in Patients With Knee Osteoarthritis Versus Controls: A Systematic Review.

PURPOSE: To assess the current scientific literature on the microbiome's relation with knee osteoarthritis (OA), with specific focuses on the gut microbiome-joint axis and joint microbiome-joint axis. METHODS: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines; the PubMed, Embase, and Cochrane databases were searched for relevant English-language clinical studies on the gut and/or joint microbiomes' association with knee OA in humans. Bias was evaluated using the Methodological Index for Non-randomized Studies score. RESULTS: Thirty-five thousand bacterial species comprise the gut microbiome; approximately 90% are members of the phyla Bacteroides and Firmicutes. Symbiosis between the gut microbiome and host under normal physiological conditions positively affects host growth, development, immunity, and longevity. Gut microbiome imbalance can negatively influence various physiological processes, including immune response, inflammation, metabolism, and joint health including the development of knee OA. In addition, next-generation gene sequencing suggests the presence of microorganisms in the synovial fluid of OA knees, and distinct microbiome profiles detected are presumed to play a role in the development of OA. Regarding the gut microbiome, consistent alterations in microbial composition between OA patients and controls are noted, in addition to several associations between certain gut bacteria and OA-related knee pain, patient-reported outcome measure performance, imaging findings, and changes in metabolic and inflammatory pathways. Regarding the joint microbiome, studies have revealed that increased levels of lipopolysaccharide and lipopolysaccharide-binding protein in synovial fluid are associated with activated macrophages-and are correlated with worsened osteophyte severity, joint space narrowing, and pain scores in knee OA patients. In addition, studies have shown various microbial composition differences in OA patients compared with controls, with certain joint microbes directly associated with OA pathogenesis, inflammation, and metabolic dysregulation. CONCLUSIONS: The gut microbiome-joint axis and joint microbiome show alterations in microbial composition between patients with OA and controls. These alterations are associated with perturbations of metabolic and inflammatory pathways, imaging findings, OA-related pain, and patient-reported outcome measure performance. LEVEL OF EVIDENCE: Level III, systematic review of Level II and III studies.

Arthroscopic Debridement of Mild and Moderate Knee Osteoarthritis Results in Clinical Improvement at Short-Term Follow-Up: A Systematic Review.

PURPOSE: To report the clinical outcomes of arthroscopic debridement for the treatment of Kellgren-Lawrence (KL) grade I and II (mild) and III (moderate) knee osteoarthritis (OA) at a minimum 1-year follow-up. METHODS: A systematic review of primary literature was performed in concordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines using the Medline, Embase, and Cochrane databases for studies regarding arthroscopic debridement/chondroplasty for management of knee OA at a minimum 1-year follow-up. Studies were included if they included KL grades I to III or dichotomized clinical outcomes by KL grade. The primary outcome was patient-reported outcome measures (PROMs) at the final follow-up. Bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) score. RESULTS: Eight studies including a total of 773 patients met inclusion criteria (range of patients in each study, 31-214). Mean age of patients ranged from 35.5 to 64 years, with most studies having a mean patient age of 55 to 65 years. Mean follow-up ranged from 1.5 to 10 years. Seven of the 8 (87.5%) studies reported good to excellent PROMs at a minimum 1- to 4-year follow-up after arthroscopic debridement. Improvements in PROMs were superior in patients with less severe knee OA (KL I-II) in comparison to KL III in most studies. Conversion to arthroplasty ranged from 7.6% to 50% in KL III patients compared with 0% to 4.5% in KL I-II patients after arthroscopic debridement. Two of the 3 studies with at least a 4-year clinical follow-up reported that clinical improvements diminished with time (improvements no longer significant in total Western Ontario and McMaster Universities Osteoarthritis Index score). The lone randomized controlled trial was the only investigation that did not find a benefit of arthroscopic debridement over quality nonoperative care. MINORS scores ranged from 6 to 10 (mean, 8.0) for the 5 nonrandomized studies without controls. CONCLUSIONS: Arthroscopic debridement for the management of mild to moderate knee OA is effective at short-term follow-up in patients who have exhausted conservative care. There is limited evidence demonstrating the durability of improvement following arthroscopic debridement after 2 years. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Bone Marrow Aspirate Concentrate Harvest Techniques for the Sports Medicine Surgeon.

The use of bone marrow aspirate concentrate (BMAC) as a surgical augment to enhance biologic healing has been gaining popularity in a variety of sports medicine procedures. Due to its reliable availability from multiple sites, including the proximal tibia, proximal humerus, and anterior superior iliac spine, BMAC can be harvested at a location selected to be adjacent to the primary procedure. This Technical Note aims to highlight 3 different harvest sites for BMAC, allowing orthopaedic sports medicine surgeons to localize their harvest site based on the proximity of the planned procedure and ultimately increase efficiency.

Orthopaedic Musculoskeletal Biologics Research Impacts Patient Care: The Second Annual Arthroscopy Orthobiologics Virtual Special Issue.

The field of orthobiologics is rapidly evolving, offering clinicians a shift in treatment from symptom relief to the potential for disease modification and tissue repair. These agents, derived from autologous tissues, components of blood, and growth factors, are used as surgical adjuncts or as standalone treatments. Their clinical applications are expanding to encompass a variety of conditions, supported by a growing base of research efforts. Arthroscopy and its companion publications are committed to evidence-based research with a robust history of publications that enhance clinical decision-making and impact patient care. This curated collection of articles highlights the year's most compelling advancements in orthopaedic musculoskeletal biologics research.