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BACKGROUND: The purpose of this study was to characterize the prevalence of venous thromboembolism (VTE; including deep vein thrombosis [DVT] and pulmonary embolism [PE]) after sports medicine knee procedures by a single surgeon at an academic institution, identify factors associated with increased risk of VTE, and determine risk factor thresholds for beyond which VTE risk is elevated. HYPOTHESIS: We hypothesized that the prevalence of VTE after sports medicine knee procedures is low, but that increasing weight and body mass index (BMI) would be associated with elevated risk. STUDY DESIGN: Retrospective case-control study. LEVEL OF EVIDENCE: Level 3. METHODS: A retrospective case-control study analyzing sports medicine knee surgeries from 2017 to 2020 was conducted using current procedural terminology codes to identify cases. Optimal cutoff points for specific continuous patient characteristics were calculated to determine elevated risk of postoperative VTE. Overall VTE-free survival was assessed using Kaplan-Meier analysis and Cox proportional hazard regression models. RESULTS: Among the 724 eligible patients, there were 13 postoperative VTE events (1.79% prevalence; 12 DVTs, 1 DVT/PE). Increasing weight and BMI were significant risk factors for postoperative VTE (P = 0.03 and P = 0.04, respectively), with weight >94.7 kg and BMI >27.9 kg/m2 associated with elevated risk in male patients and weight >79.1 kg and BMI >28.1 kg/m2 associated with elevated risk for female patients. Cox regression demonstrated a significantly increased risk of postoperative VTE for male patients with BMI ≥27.9 kg/m2. CONCLUSION: Patients who undergo sports medicine knee surgery with increased weight and BMI are at an elevated risk of postoperative VTE. An individualized approach should be considered for chemoprophylaxis in patients with these risk factors. CLINICAL RELEVANCE: Consider chemoprophylaxis in patients with increased weight and BMI who undergo sports medicine knee surgery since they are at an elevated risk of postoperative VTE.
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Embolia Pulmonar , Tromboembolia Venosa , Trombosis de la Vena , Humanos , Masculino , Femenino , Tromboembolia Venosa/epidemiología , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control , Estudios Retrospectivos , Estudios de Casos y Controles , Índice de Masa Corporal , Trombosis de la Vena/epidemiología , Trombosis de la Vena/prevención & control , Embolia Pulmonar/epidemiología , Embolia Pulmonar/etiología , Factores de Riesgo , Aumento de Peso , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/tratamiento farmacológico , Anticoagulantes/uso terapéutico , IncidenciaRESUMEN
BACKGROUND: Bone marrow aspirate concentrate (BMAC) has emerged as a therapeutic option for symptomatic knee osteoarthritis (OA). PURPOSE: To systematically review the literature to evaluate the efficacy of isolated BMAC injection in the treatment of OA of the knee joint. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was performed by searching the PubMed, Embase, and Cochrane Library databases up to July 2020 to identify human studies that assessed the clinical outcomes of isolated BMAC injection for the treatment of knee OA. The electronic search strategy used was "bone marrow aspirate concentrate knee osteoarthritis." RESULTS: Eight studies met the inclusion criteria, including a total of 299 knees with a mean follow-up of 12.9 months (range, 6-30 months). Of all patient-reported outcomes assessed across studies, 34 of 36 (94.4%) demonstrated significant improvement from baseline to latest follow-up (P < .05). Five studies evaluating numerical pain scores (visual analog scale and Numeric Rating Scale) reported significant improvements in pain level at final follow-up (P < .01). However, 3 comparative studies evaluating BMAC in relation to other therapeutic injections failed to demonstrate the clinical superiority of BMAC. CONCLUSION: The BMAC injection is effective in improving pain and patient-reported outcomes in patients with knee OA at short- to midterm follow-up. Nevertheless, BMAC has not demonstrated clinical superiority in relation to other biologic therapies commonly used in the treatment of OA, including platelet-rich plasma and microfragmented adipose tissue, or in relation to placebo. The high cost of the BMAC injection in comparison with other biologic and nonoperative treatment modalities may limit its utility despite demonstrable clinical benefit.
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Osteoartritis de la Rodilla , Médula Ósea , Trasplante de Médula Ósea , Humanos , Articulación de la Rodilla/cirugía , Osteoartritis de la Rodilla/terapia , Dolor , Resultado del TratamientoRESUMEN
BACKGROUND: In hip arthroscopic surgery, capsulotomy is performed to improve visualization and allow instrumentation of the joint. Traditionally, the defect has been left unrepaired; however, increasing evidence suggests that this may contribute to persistent pain and iatrogenic capsular instability. Nevertheless, the clinical benefit of performing routine capsular repair remains controversial. PURPOSE/HYPOTHESIS: We conducted a systematic review and meta-analysis to investigate the effects of routine capsular closure on patient-reported outcomes (PROs), hypothesizing that superior PROs would be observed with routine capsular closure. STUDY DESIGN: Meta-analysis and systematic review; Level of evidence, 4. METHODS: A systematic review and meta-analysis was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The terms "hip,""arthroscopy,""capsule,""capsular,""repair," and "closure" were used to query Ovid MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), CINAHL (Cumulative Index to Nursing and Allied Health Literature), SPORTDiscus, and PubMed. Articles with PROs stratified by capsular management were included. Multivariate mixed-effects metaregression models were implemented with study-level random-effects and fixed-effects moderators for capsular closure versus no repair and after controlling for surgical indication and preoperative PROs. The effect of repair on both the postoperative score and the change in scores was evaluated via the Harris Hip Score (HHS)/modified HHS (mHHS), Hip Outcome Score (HOS)-Activities of Daily Living (ADL), and HOS-Sport Specific Subscale (SSS), with a supplemental analysis of additional outcomes. RESULTS: Of 432 initial articles, 36 were eligible for analysis, with results for 5132 hip arthroscopic procedures. The capsule was repaired in 3427 arthroscopic procedures and unrepaired in 1705. Capsular repair was associated with significantly higher postoperative HHS/mHHS (2.011; SE, 0.743 [95% CI, 0.554-3.467]; P = .007), HOS-ADL (3.635; SE, 0.873 [95% CI, 1.923-5.346]; P < .001), and HOS-SSS (4.137; SE, 1.205 [95% CI, 1.775-6.499]; P < .001) scores as well as significantly superior improvement on the HHS/mHHS (2.571; SE, 0.878 [95% CI, 0.849-4.292]; P = .003), HOS-ADL (3.315; SE, 1.131 [95% CI, 1.099-5.531]; P = .003), and HOS-SSS (3.605; SE, 1.689 [95% CI, 0.295-6.915]; P = .033). CONCLUSION: This meta-analysis is the largest to date evaluating the effect of capsular closure on PROs and demonstrates significantly higher mean postoperative scores and significantly superior improvement with repair, while controlling for the effects of preoperative score and surgical indication. The true magnitude of the benefit of capsular repair may be clarified by large prospective randomized studies using PRO measures specifically targeted and validated for hip arthroscopic surgery/preservation.
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Artroscopía , Pinzamiento Femoroacetabular , Actividades Cotidianas , Artroscopía/métodos , Pinzamiento Femoroacetabular/cirugía , Estudios de Seguimiento , Articulación de la Cadera/cirugía , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
PURPOSE: To assess the relationship of acetabular version with the length of the anterior and posterior labrum and to introduce a developed metric, the labral index, as a means of controlling for femoral head size when measuring labral length. METHODS: One hundred forty-eight patients who underwent hip arthroscopies for femoroacetabular impingement from October 2017 to October 2019 by a single hip surgeon were retrospectively reviewed. Magnetic resonance imaging arthrogram was used to measure central acetabular version (at the center of the femoral head) and cranial acetabular version (at the midpoint between the acetabular roof and center of the femoral head), as well as labral length at the anterior, posterior, and superolateral locations (3, 9, and 12 o'clock, respectively). Labral index was calculated by dividing anterior, posterior, and superolateral labral lengths by the radius of the femoral head. Pearson correlation analysis was used to assess the association between the 2 continuous variables. A priori alpha of 0.05 was established as the cutoff for significance. RESULTS: Forty-three patients (26 female, 17 male) with an average age of 34.2 ± 11.6 years were included in analysis. Increased central anteversion was significantly associated with a larger anterior labral length and index (P = .023, r = 0.343 and .005, r = 0.415, respectively). Cranial anteversion weakly correlated with a significantly increased anterior labral index (P = .047, r = 0.304) but not with larger anterior labral length (P = .089, r = 0.262). No statistically significant association was present for central or cranial version with posterior or superolateral labral measurements. Lateral center edge angle did not correlate with labral size at any location. CONCLUSIONS: In patients undergoing hip arthroscopy for symptomatic femoroacetabular impingement, greater acetabular anteversion was significantly associated but weakly correlated with increased anterior labral length, whereas no association was found between posterior labral length and acetabular version. The labral index may be a useful metric to normalize labral length relative to the radius of the femoral head that warrants further investigation for its clinical utility in guiding labral reconstruction versus labral repair. LEVEL OF EVIDENCE: Level IV, diagnostic case series.
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The significance of graft diameter in anterior cruciate ligament reconstruction (ACLR) with soft tissue grafts is well established, with a minimum graft diameter of 8.0 mm associated with lower rates of revision surgery. Consistently achieving grafts that meet or exceed the ideal diameter of 8.0 mm is still a concern with traditional tibial screw fixation, even with quadrupled hamstring autografts. The authors hypothesized that following a simple intraoperative algorithm selectively incorporating the gracilis tendon in an 8-stranded construct for all-inside ACLR with suspensory fixation on both ends of the graft would consistently achieve graft diameters of 8.0 mm or larger by allowing more of the graft material to contribute to increased diameter instead of increased length for screw fixation, with no allograft tissue required. A total of 113 eligible cases were identified, including 70 male patients and 43 female patients (mean±SD age, 25.92±6.47 years; range, 14-49 years). All 113 grafts (100%) were at least 8.0 mm in diameter. There were 8 grafts that were 8.0 mm. Overall mean±SD graft diameter was 9.32±0.71 mm (median, 9.5 mm; range, 8.0-11.0 mm). There were no cases in which allograft tissue was needed to increase graft size. An analysis of 113 cases of all-inside hamstring autograft ACLR with dual suspensory fixation showed that a graft diameter of at least 8.0 mm was achieved in every case, without the use of allograft tissue. These results suggest that this technique for ACLR is reliable in producing grafts that meet or exceed the recommended minimum diameter of 8.0 mm. [Orthopedics. 2021;44(4):e539-e545.].
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Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Adulto , Lesiones del Ligamento Cruzado Anterior/diagnóstico por imagen , Lesiones del Ligamento Cruzado Anterior/cirugía , Autoinjertos , Femenino , Humanos , Masculino , Tendones , Tibia/cirugía , Trasplante Autólogo , Adulto JovenRESUMEN
BACKGROUND: Multiligamentous knee injuries (MLKIs) are rare, and heterogeneous in presentation and treatment options. Consequently, optimal postoperative rehabilitation of MLKI remains unclear. OBJECTIVE: To summarize the latest evidence for postoperative rehabilitation protocols following multiligamentous knee reconstruction (MLKR). PATIENTS AND METHODS: A multidatabase search was conducted with the aid of a health sciences librarian. Blinded reviewers conducted multiple screenings of studies evaluating postoperative rehabilitation protocols following MLKR. All included studies were then graded based on level of evidence, and data concerning patient demographics and rehabilitation protocols were extracted. RESULTS: MLKR rehabilitation protocols differ widely in terms of weightbearing, bracing, initiation, and types of physical therapy, yet several established protocols were referenced frequently throughout the literature. Such protocols resulted in good outcomes, with patients returning to running in 6 to 12 months and returning to sport in 8 to 12 months. CONCLUSION: The rare nature of MLKI hinders the ability to create a standardized rehabilitation protocol. However, early postoperative physical therapy and range of motion consistently lead to improved outcomes. Randomized studies are needed to determine optimal postoperative rehabilitation following MLKR.
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Traumatismos de la Rodilla/rehabilitación , Traumatismos de la Rodilla/cirugía , Ligamentos Articulares/lesiones , Ligamentos Articulares/cirugía , Terapia Combinada , Humanos , Cuidados Posoperatorios , Rango del Movimiento Articular , Recuperación de la FunciónRESUMEN
BACKGROUND: Repair of torn pectoralis major tendons is generally considered superior to nonoperative management, but there is a paucity of comparative data to demonstrate ideal repair timing and fixation methods. PURPOSE/HYPOTHESIS: The purpose was to compare the outcomes between acute and chronic repair and among the various methods of fixation (transosseous tunnels, cortical buttons, suture anchors, screws with washers, and direct repair). It was hypothesized that acute repair would have superior outcomes and there would be similar outcomes among the various methods of fixation. STUDY DESIGN: Meta-analysis. METHODS: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review of the literature was completed through MEDLINE, SPORTDiscus, CINAHL, Cochrane, Embase, and Web of Science databases. English-language studies were included with a minimum of 6 months' mean follow-up and 5 cases per study. MINORS (Methodological Index for Nonrandomized Studies) was utilized to assess the quality of the existing literature. Analysis of mechanisms of injury and meta-analysis of pooled outcomes were completed. Pooled effect sizes were calculated from random effects models. Continuous variables were assessed via mixed model analysis, with the individual study designated as a random effect and the desired treatment for comparison as a fixed effect. Bivariate frequency data were transformed through Freeman-Tukey log-linear transformation for variance stabilization and then assessed through a mixed model with a study-level random effect and subsequently back-transformed. Significance was set at P < .05. RESULTS: Twenty articles with 384 injuries met the inclusion criteria for comparison. All patients were male, with 61.9% of injuries occurring during weight training, at a mean age of 31.53 years, and with a mean follow-up of 30.12 months. Included studies scored a mean (SD) 15.53 ± 4.26 (range, 7.0-23.3) by MINORS criteria. Acute repair was significantly superior to chronic repair, with a relative improvement of functional outcome by 0.85 (P = .004) and satisfaction with cosmesis by 20.50% (P = .003). There was a trend toward acute repair having a higher proportion of patients who were pain-free (34.47%, P = .064). There were no significant differences among the methods of fixation for repair. CONCLUSION: Acute repair of pectoralis major tendon tears resulted in significantly superior functional outcomes and cosmesis satisfaction with a trend toward a higher proportion of patients who were pain-free. There were no significant differences among the methods of fixation for repair.
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Músculos Pectorales/lesiones , Músculos Pectorales/cirugía , Anclas para Sutura , Tendones , Adulto , Humanos , Resultado del Tratamiento , Extremidad SuperiorRESUMEN
BACKGROUND: The incidence of pectoralis major tendon tears is increasing, and repair is generally considered; however, a paucity of comparative data are available to demonstrate the superiority of operative treatment. PURPOSE/HYPOTHESIS: The purpose of this study is to compare the outcomes of operative and nonoperative treatment of pectoralis major tendon tears. We hypothesized that repair would result in superior outcomes compared with nonoperative treatment. METHODS: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review of the literature was completed by use of MEDLINE, SPORTDiscus, CINAHL, Cochrane, EMBASE, and Web of Science databases. We included English-language studies that had a minimum of 6 months of average follow-up and 5 cases per study. The MINORS (Methodological Index for Non-Randomized Studies) was used to assess the quality of the existing literature. Meta-analysis of pooled mechanisms of injury and outcomes was completed. Pooled effect sizes were calculated from random-effects models. Continuous variables were assessed by use of mixed-model analysis, with the individual study designated as a random effect and the desired treatment for comparison as a fixed effect. Bivariate frequency data were transformed via the Freeman-Tukey log-linear transformation for variance stabilization and then assessed through use of a mixed model with a study level random effect and subsequently back-transformed. Significance was set at P < .05. RESULTS: A total of 23 articles with 664 injuries met the inclusion criteria for comparison. All patients were male, with an average age of 31.48 years; 63.2% of injuries occurred during weight training, and the average follow-up was 37.02 months. Included studies had moderately high methodological quality. Operative treatment was significantly superior to nonoperative treatment, with relative improvements of functional outcome by 23.33% (0.70 improvement by Bak criteria which is scored 1-4; P = .027), full isometric strength 77.07% (P < .001), isokinetic strength 28.86% (P < .001) compared with the uninjured arm, cosmesis satisfaction 13.79% (P = .037), and resting deformity 98.85% (P < .001). The overall complication rate for operative treatment was 14.21%, including a 3.08% rate of rerupture. CONCLUSION: Pectoralis major tendon repair resulted in significantly superior outcomes compared with nonoperative treatment, with an associated 14.21% complication rate. Statistically significant improvements were noted in functional outcome, isokinetic strength, isometric strength, cosmesis, and resting deformity.
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INTRODUCTION: Hip arthroscopy is a commonly performed procedure that carries a notable risk of nerve injury secondary to port placement and the use of axial traction. Sensory neurapraxia of the pudendal nerve and the lateral femoral cutaneous nerve is most common; however, sexual dysfunction and sciatic nerve injury has also been reported. Reported incidence of nerve injury ranges between 1.4% and 5% in the literature, but much of these data are based on unsolicited patient concerns. This study aimed to determine the true rate of nerve injury among this patient population through administration of a validated survey at multiple time points. METHODS: A prospective study of all patients undergoing hip arthroscopy requiring traction by a single surgeon at our institution was performed. These cases were the first 100 hip arthroscopies performed in practice by the surgeon. Before surgery, all patients were asked about the presence of neuropathic symptoms including sexual dysfunction through administration of a validated questionnaire. The same questionnaire was then administered at several time points postoperatively: on the day of surgery, on postoperative day 2, at the first follow-up visit, and if symptoms persisted, then at each follow-up appointment until resolution of the symptoms. Overall incidence of nerve injury was then calculated. Subgroup analyses were performed to investigate whether traction time, sex, body mass index (BMI), or technically demanding surgical skills affected the incidence. RESULTS: This study included a total of 100 patients with an average age of 29 (13 to 62) years and an average BMI of 25. Nerve injury was seen in 13 patients with an incidence of 13%. Specific nerves injured included the pudendal (9), lateral femoral cutaneous (2), sciatic (1), and superficial peroneal nerves (1). Subgroup analysis did not demonstrate a notable association between the risk of nerve injury and increased traction time, sex, or increased BMI. The technically demanding surgical skills was associated with a notable decrease in the traction time, but no notable difference in the risk of nerve injury was observed. Most nerve injuries resolved within 2 weeks (8 of 13), and all cases of nerve injury resolved within 9 months. DISCUSSION AND CONCLUSIONS: The incidence of nerve injury after hip arthroscopy may be markedly higher than previously reported; however, resolution seems to occur as previously found in the literature. Patients should be educated regarding the risk of nerve injury during this procedure. LEVEL OF EVIDENCE: Level IV.
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Artroscopía/efectos adversos , Articulación de la Cadera/cirugía , Traumatismos de los Nervios Periféricos/etiología , Adolescente , Adulto , Artroscopía/métodos , Índice de Masa Corporal , Competencia Clínica , Femenino , Nervio Femoral/lesiones , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Traumatismos de los Nervios Periféricos/epidemiología , Nervio Peroneo/lesiones , Complicaciones Posoperatorias , Nervio Pudendo/lesiones , Nervio Ciático/lesiones , Factores Sexuales , Factores de Tiempo , Adulto JovenRESUMEN
CASE: A 36-year-old woman sustained a medial tibial plateau fracture involving a tibial tunnel that had been used 4 years prior for an anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BPTB) allograft in the same knee. At 26 months following open reduction and internal fixation of the tibial plateau fracture (6 years following the index ACL reconstruction), the patient returned to full activity. CONCLUSION: To our knowledge, this is the first report of a tibial plateau fracture following ACL reconstruction with a BPTB allograft, which adds to the paucity of literature discussing tibial plateau fractures following ACL reconstruction and discusses the potential predisposing factors to fracture such as ACL graft selection and surgical technique.
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Reconstrucción del Ligamento Cruzado Anterior , Ligamento Rotuliano/trasplante , Tibia , Adulto , Reconstrucción del Ligamento Cruzado Anterior/efectos adversos , Reconstrucción del Ligamento Cruzado Anterior/métodos , Femenino , Humanos , Tibia/lesiones , Tibia/cirugía , Tibia/trasplante , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/etiología , Trasplante AutólogoRESUMEN
BACKGROUND: No meta-analysis has compared outcomes of operative and nonoperative proximal hamstring avulsion treatment. PURPOSE: To compare outcomes of operative and nonoperative proximal hamstring avulsion treatment, including acute, chronic, partial, and complete repairs. STUDY DESIGN: Meta-analysis. METHODS: PubMed, CINAHL, SPORTdiscus, Cochrane Library, EMBASE, and Web of Science were searched up to July 2016. Three authors screened the studies and performed quality assessment using criteria from the Methodologic Index for Nonrandomized Studies. A best evidence synthesis was subsequently used. RESULTS: Twenty-four studies (795 proximal hamstring avulsions) were included. Twenty-two studies included proximal hamstring avulsion repairs; 1 study had proximal hamstring avulsion repairs and a control group of nonoperatively treated proximal hamstring avulsions; and 1 study had solely nonoperatively treated proximal hamstring avulsions. The majority of studies were of low methodological quality. Overall, repairs had significantly higher patient satisfaction (90.81% vs 52.94%), hamstring strength (85.01% vs 63.95%), Lower Extremity Functional Scale scores (72.77 vs 69.53), and single-legged hop test results (119.1 vs 56.62 cm) (all P < .001); complications occurred in 23.17% of cases. Compared with chronic repairs, acute avulsion repairs had greater patient satisfaction (95.48% vs 83.79%), less pain (1.07 vs 3.71), and greater strength (85.2% vs 82.8%), as well as better scores for the Lower Extremity Functional Scale (75.64 vs 71.5), UCLA activity scale (University of California, Los Angeles; 8.57 vs 8.10), and Single Assessment Numeric Evaluation (93.36 vs 86.50) (all P < .001). Compared with partial avulsion repairs, complete avulsion repairs had higher patient satisfaction (89.64% vs 81.35%, P < .001), less pain (1.87 vs 4.60, P < .001), and higher return to sport or preinjury activity level, but this was insignificant (81.43% vs 73.83%, P = .082). Partial avulsion repairs had better hamstring strength (86.04% vs 83.71%, P < .001) and endurance (107.13% vs 100.17%, P < .001). Complete repairs had significantly higher complication rates (29.38% vs 11.27%, P = .001). CONCLUSION: Proximal hamstring avulsion repair resulted in superior outcomes as compared with nonoperative treatment, although the complication rate was 23.17%. The nonoperative group was quite small, making a true comparison difficult. Acute repairs have better outcomes than do chronic repairs. Complete avulsion repairs had higher patient satisfaction, less pain, and a higher complication rate than partial avulsion repairs, although partial avulsion repairs had better hamstring strength and endurance. Studies of high methodological quality are lacking in terms of investigating the outcomes of proximal hamstring avulsion repairs.
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Músculos Isquiosurales/lesiones , Traumatismos en Atletas/fisiopatología , Traumatismos en Atletas/cirugía , Traumatismos en Atletas/terapia , Músculos Isquiosurales/fisiología , Músculos Isquiosurales/cirugía , Humanos , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Satisfacción del Paciente , Recuperación de la Función , Proyectos de Investigación/normas , Rotura/cirugía , Resultado del TratamientoRESUMEN
Wear debris-induced osteolysis is a major cause of orthopedic implant aseptic loosening, and various cell types, including macrophages, monocytes, osteoblasts, and osteoclasts, are involved. We recently showed that mesenchymal stem/osteoprogenitor cells (MSCs) are another target, and that endocytosis of titanium (Ti) particles causes reduced MSC proliferation and osteogenic differentiation. Here we investigated the mechanistic aspects of the endocytosis-mediated responses of MSCs to Ti particulates. Dose-dependent effects were observed on cell viability, with doses >300 Ti particles/cell resulting in drastic cell death. To maintain cell viability and analyze particle-induced effects, doses <300 particles/cell were used. Increased production of interleukin-8 (IL-8), but not IL-6, was observed in treated MSCs, while levels of TGF-ß, IL-1ß, and TNF-α were undetectable in treated or control cells, suggesting MSCs as a likely major producer of IL-8 in the periprosthetic zone. Disruptions in cytoskeletal and adherens junction organization were also observed in Ti particles-treated MSCs. However, neither IL-8 and IL-6 treatment nor conditioned medium from Ti particle-treated MSCs failed to affect MSC osteogenic differentiation. Among other Ti particle-induced cytokines, only GM-CSF appeared to mimic the effects of reduced cell viability and osteogenesis. Taken together, these results strongly suggest that MSCs play both responder and initiator roles in mediating the osteolytic effects of the presence of wear debris particles in periprosthetic zones.