The Effect of Lower Limb Alignment on Tibiofemoral Joint Contact Biomechanics after Medial Meniscus Posterior Root Repair: A Finite-Element Analysis.

INTRODUCTION: The purpose of this study was to determine how variations in lower limb alignment affect tibiofemoral joint contact biomechanics in the setting of medial meniscus posterior root tear (MMPRT) and associated root repair. METHODS: A finite-element model of an intact knee joint was developed. Limb alignments ranging from 4° valgus to 8° varus were simulated under a 1,000 N compression load applied to the femoral head. For the intact, MMPRT, and root repair conditions, the peak contact pressure (PCP), total contact area, mean and maximum local contact pressure (LCP) elevation, and total area of LCP elevation of the medial tibiofemoral compartment were quantified. RESULTS: The PCP and total contact area of the medial compartment in the intact knee increased from 2.43 MPa and 361 mm 2 at 4° valgus to 9.09 MPa and 508 mm 2 at 8° of varus. Compared with the intact state, in the MMPRT condition, medial compartment PCP was greater and the total contact area smaller for all alignment conditions. Root repair roughly restored PCPs in the medial compartment; however, this ability was compromised in knees with increasing varus alignment. Specifically, elevations in PCP relative to the intact state increased with increasing varus, as did the total contact area with LCP elevation. After root repair, medial compartment PCP remained elevated above the intact state at all degrees tested, ranging from 0.05 MPa at 4° valgus to 0.27 MPa at 8° of varus, with overall PCP values increasing from 2.48 to 9.09 MPa. For varus alignment greater than 4°, root repair failed to reduce the total contact area with LCP elevation relative to the MMPRT state. DISCUSSION: Greater PCPs and areas of LCP elevation in varus knees may reduce the clinical effectiveness of root repair in delaying or preventing the development of tibiofemoral osteoarthritis.

Anatomic total shoulder arthroplasty with inlay glenoid component: A systematic review.

Background: A total shoulder arthroplasty (TSA) system utilizing an inlay glenoid component has been proposed as a means of reducing glenoid component loosening while still providing patients with desirable functional and clinical outcomes. The purpose of this study was to systematically review current outcomes literature on TSA using an inlay glenoid component. Methods: A literature search was conducted using PubMed/MEDLINE, Cochrane Database of Systematic Reviews, and Web of Science databases. Studies comparing pre- and postoperative functional and clinical outcomes were included. Results: Five studies with 148 shoulders (133 patients) were included. Patient-reported outcomes improved, including the American Shoulder and Elbow Surgeons score (mean change 34.1 to 80.6), Penn Shoulder Score (mean change 43.3 to 85.5), Single Assessment Numeric Evaluation score (mean change 34.1 to 80.6), and visual analog scale-pain (mean change 6.9 to 1.6). Range of motion improved for forward elevation (mean change 109.6 to 156.2) and external rotation (mean change 21.5 to 50.8). Glenoid component loosening occurred in one shoulder (0.68%). Two revision surgeries (1.35%) were performed. Discussion: The use of an inlay glenoid component is associated with improvements in postoperative pain, function, and satisfaction while minimizing rates of glenoid component loosening and the need for revision surgery over short-term follow-up. Level of evidence: systematic review, level IV.

Lower Extremity Surfing Injuries Seen at United States Emergency Departments From 2002 to 2022.

Background: Surfing is an increasingly popular sport with a high propensity for both traumatic and atraumatic injuries. Purpose: To analyze the trends, etiologies, and diagnoses of lower extremity orthopaedic-related surfing injuries presenting to United States (US) emergency departments (EDs) within a 21-year study period. Study Design: Descriptive epidemiology study. Methods: The National Electronic Injury Surveillance System database was queried for data on lower extremity surfing injuries presenting to US EDs from January 1 to December 31, 2022. Data collected included year, injury mechanism, injury location, diagnosis, and disposition. The raw data were used to calculate national estimates (NEs) based on each hospital's assigned statistical sample weight. Linear regressions were performed to analyze annual trends. Results: A total of 776 lower extremity surfing injuries were included (NE = 49,218 injuries). The mean age of the patients was 29.4 ± 13.6 years. The most common injured areas were the foot (NE = 17,411; 35.4%), lower leg (NE = 8673, 17.6%), and knee (NE = 8139; 16.5%). The most common mechanism of injury was impact with board (NE = 17,144; 34.8%), and the most common fracture locations were the lower leg (NE = 1195; 29.5%), ankle (NE = 1594; 24.5%), and foot (NE = 1495; 23.0%). There were statistically significant decreases in weighted estimates for lower extremity surfing injuries by 108 per year (P < .001), for lacerations by 76 per year (P < .001), and for sprains by 18 per year (P = .01). Impact-with-board injuries decreased by 59 injuries per year (P < .001) and constituted 63.5% of lacerations and 12.1% of fractures. Only 3.9% of patients were admitted for hospitalization. Conclusion: There was a decreasing trend in lower extremity surfing injuries presenting to US EDs during the 21-year study period.

Outcomes of the Latarjet procedure in female patients: A case series and matched-pair analysis.

Background: The objective of this study was to retrospectively report on the outcomes of female patients undergoing the Latarjet procedure. Methods: Female patients undergoing the Latarjet procedure with minimum 1 year follow-up were identified and contacted to obtain Numeric Pain Rating Scale (NPRS), Subjective Shoulder Value (SSV), and return to sport (RTS) data. Eligible females were then matched 1:1 with a male counterpart based on laterality and age (± 3 years), and outcomes compared. Results: A total of 20 female patients with a mean follow-up of 73.8 months reported postoperative NPRS and SSV scores of 2.2 ± 2.3 and 69.3 ± 22.0, respectively. Of the nine athletes, 3 (33%) reported a successful RTS at a mean of 9 months. Four patients (20.0%) required reoperation at a mean of 27.1 months. The matched analysis demonstrated similar NPRS scores between male and female patients and a trend towards lower SSV scores and rates of RTS. Conclusion: At mid-term follow-up female patients reported pain levels similar to female-specific literature reports, but overall low subjective shoulder function and RTS. Compared to propensity-matched males, females reported similar levels of pain, lower shoulder function, and lower rates of RTS, however, differences did not reach statistical significance. Level of Evidence: IV, retrospective case series.

Clinical and radiographic outcomes of the modified McLaughlin procedure for locked posterior dislocation of the shoulder: a systematic review.

Background: Multiple treatment options for locked posterior dislocation of the shoulder (LPDS) have been described, including the modified McLaughlin procedure. The purpose of this review, therefore, was to perform a systematic review of the literature to synthesize the available data reporting on the clinical and radiographic outcomes of patients undergoing the modified McLaughlin procedure for the treatment of LPDS. Methods: A systematic review of the PubMed Central, MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library databases from inception through January 2023 was performed. Outcomes studies reporting on clinical and radiographic outcomes in patients undergoing the modified McLaughlin procedure for LPDS were included. Postoperative complications and episodes of recurrent instability were noted. Results: A total of 1322 studies were initially identified, of which 9 were deemed eligible for inclusion in our review. Among included studies, a total of 97 shoulders (96 patients) with a mean age of 37.7 years (range, 26-51) were identified. The most common mechanisms of injury included trauma, seizure, and electrocution. Reverse Hill-Sachs lesions ranged in size from 20% to 50% of the humeral head articular surface. At final follow-up, the weighted mean University of California at Los Angeles shoulder score, Constant-Murley Score, American Shoulder and Elbow Surgeons shoulder score, and visual analog scale for pain score were 29 (range, 27-31), 75 (range, 65-92), 92 (range, 83-98), and 1.9 (range, 1-2.4), respectively. Postoperative Constant-Murley Score and University of California at Los Angeles scores were highest in the one study reporting exclusively on treatment during the acute period. Weighted mean postoperative forward flexion, abduction, external rotation, and internal rotation were 154° (range, 102-176), 144° (range, 118-171), 64° (range, 44-84), and 47° (range, 42-56), respectively. Osteointegration of the lesser tuberosity was noted in all patients at the final follow-up. Postoperative complications occurred in one patient (1.0% of cohort); a screw migration successfully treated with operative removal. Recurrent instability was noted in two epileptic patients (2.1% of cohort). Conclusion: The literature surrounding the use of the modified McLaughlin procedure for LPDS remains sparse. This review demonstrates that this procedure is associated with favorable clinical and radiographic outcomes with overall low rates of complication and recurrent instability, especially when the time from injury to surgery is minimized. These findings illustrate that in patients presenting with LPDS and a reverse Hill-Sachs lesion between 20% and 50% of the humeral head articular surface, the modified McLaughlin procedure is a safe and effective treatment option.

Early Postoperative Complications and Associated Variables After Tibial Tubercle Osteotomy: A 15-Year Experience From a Single Academic Institution.

Background: Tibial tubercle osteotomy (TTO) is a well-established surgical treatment option for patients with patellofemoral disorders. Purpose: To determine the rate of early (≤90 day) postoperative complications after TTO and variables related to postoperative complications. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent TTO at a single academic institution within a 15-year period (2008-2022) were identified. All patients with a minimum 90-day follow-up were considered for study inclusion. Exclusion criteria were age younger than 14 years and revision surgery. Patient characteristics, surgical history, and concomitant procedures were identified, and risk factor analysis was performed to identify variables associated with early postoperative complications. Results: A total of 344 knees in 313 patients met eligibility criteria and were included in the final analysis. One intraoperative complication (0.3%), a premature closure of the incision before repair of the vastus medialis, was identified. There were 141 postoperative complications (138 surgical, 3 medical) in 118 patients for a complication rate of 34.3%. The most common complications were stiffness requiring a nonstandard-of-care intervention (16.3%), superficial wound infection/wound dehiscence (8.1%), and hemarthrosis/effusion requiring aspiration (5.8%). Patients experiencing postoperative complications were older (mean difference, 3.49 years; 95% CI, 1.26-5.73 years; P = .002), had a higher mean Charlson Comorbidity Index (mean difference, 0.26; 95% CI, 0.08-0.45; P = .006), and were more likely to be current smokers (P = .015) compared with patients with no complications. Inpatient surgery (defined as surgery in a hospital setting with at least 1 overnight stay) was associated with postoperative complications (odds ratio [OR], 2.29; 95% CI, 1.39-3.77; P = .001); this association remained significant generation of a multivariate model (OR, 2.07; 95% CI, 1.19-3.58; P = .010). Previous surgery on the ipsilateral knee (P < .001) and concomitant autologous chondrocyte implantation (P = .046) were also associated with postoperative complications. Conclusion: The study findings indicated a low intraoperative complication rate (0.3%) and a relatively high early postoperative (≤90 day) complication rate (34.3%) after TTO. Variables associated with postoperative complications included greater age, higher Charlson Comorbidity Index, surgery in an inpatient setting, previous surgery on the ipsilateral knee, and concomitant autologous chondrocyte implantation.

Decreasing Trend in Upper Extremity Surfing Injuries Presenting to United States Emergency Departments - A 20-Year Analysis.

Surfing is a globally popular recreational sport with limited epidemiologic data. Currently, there is a paucity of literature regarding injury profiles and mechanisms of orthopaedic-related injuries. This study analyzed trends, etiologies, and diagnoses of upper extremity orthopaedic-related surfing injuries presenting to United States (US) emergency departments. The National Electronic Injury Surveillance System database was accessed to query upper extremity surfing-related injuries presenting to US emergency departments from January 1, 2002 to December 31, 2021. Data were analyzed for year, body part, mechanism of injury, diagnosis, and disposition. National estimates were calculated based on the assigned statistical sample weight of each hospital. A total of 33 323 surfing-related injuries were included. The most common upper extremity body parts involved 15 169 shoulders (45.5%), 4220 fingers (12.7%), and 3753 hands (11.3%). The most common identifiable mechanisms of injuries were 7474 board-to-body (22.4%), 4188 impact with sand (12.6%), and 2639 impact with water (7.9%). Overuse constituted 7.2% of overall upper extremity injuries but 40% of strains. Only 2.2% of injuries required hospital admission. Between 2002 and 2021, there was a decreasing annual trend in upper extremity surfing-related injuries (P=.01). The decreasing trend in emergency department visits may be due to urgent care utilization and training for surfers and lifeguards to manage these injuries on-site, as the majority were minor given the small proportion requiring hospital admission. Chronic stress on rotator cuff and peri-scapular musculature while paddling in the prone position likely contributed to the large proportion of overuse injury.

Early Postoperative Complications and Associated Variables After High Tibial Osteotomy and Distal Femoral Osteotomy: A 15-Year Experience From a Single Academic Institution.

BACKGROUND: High tibial osteotomy (HTO) and distal femoral osteotomy (DFO) are well-recognized treatments to address varus and valgus malalignment, respectively, in the setting of symptomatic unicompartmental arthritis of the tibiofemoral joint. The existing literature is limited in its ability to characterize complications after HTO or DFO procedures. PURPOSE: The objective of this study was to determine the rate of early (≤90 days) postoperative complications and associated variables from the 15-year experience of a single academic institution. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients treated at a single academic institution between 2008 and 2022 who underwent HTO or DFO procedures were identified. All patients with minimum 90-day follow-up were considered for inclusion in the study. Exclusion criteria were inadequate follow-up, unavailable medical records, age <14 years, and revision osteotomy. Patient demographic characteristics, surgical history, and concomitant procedures were identified, and risk factor analysis was performed to identify variables associated with early postoperative complications. All intraoperative complications were recorded. RESULTS: A total of 243 knees in 232 patients met eligibility and were included in the final analysis. Three intraoperative complications (1.2%) involving fracture extension of the osteotomy occurred. There were 127 early postoperative complications (121 surgical, 6 medical) in 102 knees (68 with HTO and 34 with DFO). Medical complications included pulmonary embolus in 3 patients (1.2%), urinary tract infection in 2 patients (0.8%), and postoperative ileus requiring prolonged hospitalization in 1 patient (0.4%). The most common complications were stiffness requiring a non-standard of care intervention (17.7%), superficial wound infection or wound dehiscence (13.2%), and hemarthrosis or effusion requiring aspiration (6.6%). The rate of deep infection requiring irrigation and debridement was 4.1%. Variables associated with early postoperative complications included smoking (odds ratio [OR], 3.05; 95% CI, 1.34-6.94; P = .008), concomitant chondroplasty and/or loose body removal (OR, 2.55; 95% CI, 1.50-4.33; P = .001), and concomitant ligament reconstruction (OR, 3.97; 95% CI, 1.37-11.53; P = .011). CONCLUSION: These 15-year data revealed a low rate of intraoperative complications (1.2%) and a relatively high rate of early (≤90 days) postoperative complications (42.0%) after an HTO or DFO procedure. Surgeons should be aware of the increased postoperative complications associated with smoking, concomitant chondroplasty, and concomitant ligament reconstruction and should use this information to counsel patients regarding appropriate expectations in the postoperative period.

Trends in Patient-Reported Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Background: Despite the prevalence of patient-reported outcomes (PROs) to evaluate results after anterior cruciate ligament (ACL) reconstruction, there exists little standardization in how these metrics are reported, which can make wider comparisons difficult. Purpose: To systematically review the literature on ACL reconstruction and report on the variability and temporal trends in PRO utilization. Study Design: Systematic review. Methods: We queried the PubMed Central and MEDLINE databases from inception through August 2022 to identify clinical studies reporting ≥1 PRO after ACL reconstruction. Only studies with ≥50 patients and a mean 24-month follow-up were considered for inclusion. Year of publication, study design, PROs, and reporting of return to sport (RTS) were documented. Results: Across 510 studies, 72 unique PROs were identified, the most common of which were the International Knee Documentation Committee score (63.3%), Tegner Activity Scale (52.4%), Lysholm score (51.0%), and Knee injury and Osteoarthritis Outcome Score (35.7%). Of the identified PROs, 89% were utilized in <10% of studies. The most common study designs were retrospective (40.6%), prospective cohort (27.1%), and prospective randomized controlled trials (19.4%). Some consistency in PROs was observed among randomized controlled trials, with the most common PROs being the International Knee Documentation Committee score (71/99, 71.7%), Tegner Activity Scale (60/99, 60.6%), and Lysholm score (54/99, 54.5%). The mean number of PROs reported per study across all years was 2.89 (range, 1-8), with an increase from 2.1 (range, 1-4) in studies published before 2000 to 3.1 (range, 1-8) in those published after 2020. Only 105 studies (20.6%) discretely reported RTS rates, with more studies utilizing this metric after 2020 (55.1%) than before 2000 (15.0%). Conclusion: There exists marked heterogeneity and inconsistency regarding which validated PROs are used in studies related to ACL reconstruction. Significant variability was observed, with 89% of measures being reported in <10% of studies. RTS was discretely reported in only 20.6% of studies. Greater standardization of outcomes reporting is required to better promote objective comparisons, understand technique-specific outcomes, and facilitate value determination.

Outcomes of subacromial balloon spacer implantation for irreparable rotator cuff tears: a systematic review and meta-analysis.

BACKGROUND: The management of irreparable rotator cuff tears remains a topic of considerable debate among orthopedic surgeons. Currently, there is little consensus regarding the gold-standard treatment; however, an emerging option involves the use of a biodegradable subacromial spacer. The purpose of this study, therefore, was to systematically review and synthesize the current literature reporting on the clinical outcomes following implantation of a subacromial balloon spacer (SABS) for the treatment of patients with irreparable rotator cuff tears. METHODS: A systematic review of the PubMed Central, MEDLINE, Embase, Scopus, and Cochrane Library databases from inception through December 2022 was performed. Clinical outcome studies reporting on functional and clinical outcomes, as well as postoperative complications, were included. RESULTS: A total of 127 studies were initially identified, of which 28 were deemed eligible for inclusion in our review. Of these studies, 17 reported adequate preoperative and postoperative data (mean and a measure of variance) and thus were included in the meta-analysis. Among the included studies, a total of 894 shoulders (886 patients) were included; the mean age was 67.4 years (range, 61.7-76.2 years). The average follow-up period was 30.4 months (range, 12-56 months). All postoperative patient-reported outcomes improved significantly from baseline, including the Constant score (mean difference, 33.53; P < .001), American Shoulder and Elbow Surgeons score (mean difference, 40.38; P < .001), Oxford Shoulder Score (mean difference, 12.05; P = .004), and visual analog scale pain score or Numeric Pain Rating Scale score (mean difference, -3.79; P < .001). Forward elevation (mean difference, 24°; P < .001), abduction (mean difference, 52°; P = .02), and external rotation (mean difference, 15°; P < .001) improved. Device-related complications occurred at a rate of 3.6%, the most common of which were balloon migration (1.0%) and synovitis (0.6%). Ultimately, 5% of patients required salvage reverse shoulder arthroplasty. CONCLUSION: Short-term outcomes suggest that SABS implantation can be a safe and effective treatment and appears to be associated with early improvements in postoperative pain and function. Clinical heterogeneity, use of concomitant procedures, and variations in patient selection limit our ability to conclusively interpret the available evidence. We do not yet know the potential therapeutic value of SABS implantation relative to other currently accepted treatment strategies, the length of symptomatic improvement that can be expected, or the long-term implications of SABS use on the outcomes of further salvage procedures.

Inconsistencies in reporting risk factors for ulnar collateral ligament reconstruction failure: a systematic review.

BACKGROUND: When return to sport (RTS) at a competitive level is desired, treatment of injury to the ulnar collateral ligament (UCL) frequently involves surgical reconstruction. Although RTS rates between 66% and 98% have been reported, there remains a paucity of comparative clinical studies, with far fewer reporting statistically significant risk factors for reconstruction failure. The goal of this study was to perform a systematic review of the literature to demonstrate the variety and inconsistency with which risk factors associated with reconstruction failure are reported. MATERIALS AND METHODS: A systematic review of the PubMed Central and MEDLINE databases was performed to identify clinical outcome studies reporting ≥1 statistically significant risk factor associated with failure of UCL reconstruction. Failure was defined as (1) reinjury, recurrent instability, or need for revision surgery; (2) failure show improvement in postoperative patient-reported outcomes (PROs); or (3) failure to RTS at the preinjury level (RSL). RESULTS: A total of 349 unique studies were initially identified, of which 12 were deemed eligible for inclusion in our study. Of these 12 studies, 4 defined outcomes based on recurrent instability, reinjury, or revision surgery; 2 defined outcomes based on PROs; and 6 defined outcomes based on RSL. In the group with instability, reinjury, or revision failure, 11 significant risk factors were identified across all studies: age, height, body mass index, professional experience, injury to the nondominant arm, history of competitive throwing, mechanism of injury, history of a psychiatric diagnosis, presence of preoperative instability or stiffness, postoperative workload, and time to RTS. In the PRO failure group, 12 risk factors were identified across all studies: age, status as a military cadet, injury to the nondominant arm, graft type, baseball position, current injury to the ipsilateral arm, current level of competition attributed to reconstruction surgery, shoulder surgery after reconstruction, no competitive throwing history, non-throwing mechanism of injury, history of a psychiatric diagnosis, and preoperative instability or stiffness. In the RSL failure group, 4 risk factors were identified across all studies: age, ulnar neuritis, level of professional play, and amount of time spent at the professional level. CONCLUSIONS: Age, level of professional play prior to surgery, postoperative workload, and time at the professional level are the most commonly reported risk factors associated with UCL reconstruction failure. There remains a paucity of data associating risk factors with patient-specific outcomes and marked levels of inconsistency and conflict among the studies that report such data.

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis.

CONTEXT: The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players. OBJECTIVE: To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries. DATA SOURCES: A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases. STUDY SELECTION: Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length. STUDY DESIGN: The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR. RESULTS: The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up. CONCLUSION: Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Biomechanical comparison of Tibial-sided supplemental fixation techniques in Bone-Patellar Tendon-Bone anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to compare the biomechanical properties of a commercially available suture anchor and a screw post for supplemental tibial fixation of a bone-patellar tendon-bone (BTB) graft at time zero. We hypothesized that supplemental fixation using a suture anchor would demonstrate similar biomechanical performance in comparison with a screw post. METHODS: Sixteen fresh frozen, healthy human cadaveric knees underwent BTB autograft harvest, placement, and primary tibial-sided interference screw fixation using a standardized technique performed by a single surgeon. Specimens were randomly assigned to one of two tibial-sided supplemental fixation groups (suture anchor or screw post), yielding eight specimens in each group. Each specimen was affixed to a custom loading apparatus, with the tibial tunnel aligned in a vertical position that allowed for parallel "worst-case scenario" loading and eliminated loading variation due to tibial tunnel angle. Grafts were pretensioned to 30 N and biomechanical performance was compared with respect to cyclical loading between 50-250 N for 500 cycles at 0.5 Hz and pull-to-failure loading at 60 mm/min. RESULTS: The suture anchor and screw post supplemental constructs demonstrated similar performance with respect to all biomechanical parameters assessed, including yield strength (294.0 N [IQR 267.2-304.2 N] versus 332.1 N [IQR 313.8-350.4 N]; P = 0.079) and ultimate strength (330.1 N [IQR 306.9-418.7 N] versus 374.7 N [IQR 362.0-387.3 N]; P = 0.3798). However, of the eight original specimens in each group, one suture anchor specimen (12.5%) and six metallic screw post specimens (75%) failed during cyclical testing and were unable to undergo displacement and load to failure testing. CONCLUSION: This study provides preliminary evidence that supplemental tibial-sided fixation of a BTB ACL graft with a suture anchor has similar loading characteristics or load-to-failure strength when compared to supplemental fixation with a screw post construct. STUDY DESIGN: Laboratory Controlled Study. LEVEL OF EVIDENCE: Basic Science Study.

Modeling Controlled Cortical Impact Injury in 3D Brain-Like Tissue Cultures.

Traumatic brain injury (TBI) survivors suffer long term from mental illness, neurodegeneration, and neuroinflammation. Studies of 3D tissue models have provided new insights into the pathobiology of many brain diseases. Here, a 3D in vitro contusion model is developed consisting of mouse cortical neurons grown on a silk scaffold embedded in collagen and used outcomes from an in vivo model for benchmarking. Molecular, cellular, and network events are characterized in response to controlled cortical impact (CCI). In this model, CCI induces degradation of neural network structure and function and release of glutamate, which are associated with the expression of programmed necrosis marker phosphorylated Mixed Lineage Kinase Domain Like Pseudokinase (pMLKL). Neurodegeneration is observed first in the directly impacted area and it subsequently spreads over time in 3D space. CCI reduces phosphorylated protein kinase B (pAKT) and Glycogen synthase kinase 3 beta (GSK3ß) in neurons in vitro and in vivo, but discordant responses are observed in phosphprylated ribosomal S6 kinase (pS6) and phosphorylated Tau (pTau) expression. In summary, the 3D brain-like culture system mimicked many aspects of in vivo responses to CCI, providing evidence that the model can be used to study the molecular, cellular, and functional sequelae of TBI, opening up new possibilities for discovery of therapeutics.

Engineering advanced neural tissue constructs to mitigate acute cerebral inflammation after brain transplantation in rats.

Stroke, traumatic brain injuries, and other similar conditions often lead to significant loss of functional brain tissue and associated disruption of neuronal signaling. A common strategy for replacing lost neurons is the injection of dissociated neural stem cells or differentiated neurons. However, this method is unlikely to be suitable for replacing large brain cavities, and the resulting distribution of neurons may lack the necessary architecture to support appropriate brain function. Engineered neural tissues may be a viable alternative. Cell death is a prominent concern in neuronal grafting studies, a problem that could be magnified with the transplantation of engineered neural tissues. Here, we examined the effect of one contributor to cell death, acute cerebral inflammation, on neuronal survival after the transplantation of bioengineered constructs based on silk scaffolds. We found evidence of a high degree of inflammation and poor neuronal survival after introducing engineered constructs into the motor cortex of rats. Integrating a corticosteroid (methylprednisolone) into the constructs resulted in significantly improved neuron survival during the acute phase of inflammation. The improved construct survival was associated with decreased markers of inflammation and an anti-inflammatory state of the immune system due to the steroid treatment.