A finite element analysis of patellofemoral joint biomechanics: Exploring potential causes of postoperative anterior knee pain following unicompartmental knee arthroplasty.

Purpose: Anterior knee pain is a common complication following unicompartmental knee arthroplasty (UKA). This study aimed to elucidate the mechanism of anterior knee pain after UKA by examining the biomechanical characteristics of the patellofemoral joint. Methods: This study employs the finite element analysis method. A healthy model of the right lower limb was created using CT scans of an intact right lower limb from a healthy woman. Based on this model, a preoperative pathological model was generated by removing the meniscus and part of the articular cartilage. The UKA prosthesis was then applied to this model with five different bearing thicknesses: 5 mm, 7 mm, 10 mm, 11 mm, and 13 mm. To simulate various degrees of knee joint flexion, the femur was rotated relative to the knee joint's rotational axis, producing lower limb models at flexion angles of 0°, 30°, 60°, 90°, and 120°. We applied a constant force from the center of the femoral head to the center of the ankle joint to simulate lower limb loading during squatting. The simulations were conducted using Ansys 17.0. Results: Both overstuffing and understuffing increased the peak stress on the patellar cartilage, with overstuffing having a more pronounced effect. Compared to healthy and balanced models, overstuffed and understuffed models exhibited abnormal stress distribution and stress concentration in the patellar cartilage during knee flexion. Conclusion: Overstuffing and understuffing lead to residual varus or valgus deformities after UKA, causing mechanical abnormalities in the patellofemoral joint. These abnormalities, characterized by irregular stress distribution and excessive stress, result in cartilage damage, exacerbate wear in the patellofemoral joint and consequently lead to the occurrence of anterior knee pain.

Mitigating calcar fracture risk with automated impaction during total hip arthroplasty.

Background: Automated broaching has recently been introduced for total hip arthroplasty (THA), with the goal of improving surgical efficiency and reducing surgeon workload. While studies have suggested that this technique may improve femoral sizing and alignment, little has been published regarding its safety, particularly with regard to calcar fractures. The purpose of our study was to evaluate the risk of calcar fracture during automated broaching, and to determine if this risk can be mitigated. Methods: We queried our prospective institutional database and identified 1596 unilateral THAs performed by the senior author using automated impaction between 2019 and 2023. We identified the incidence of calcar fracture with automated impaction, and whether the fracture occurred during broaching or stem insertion. We additionally determined calcar fracture incidence within two consecutive subgroups of patients using different stem insertion techniques; subgroup (1): automated broaching with automated stem insertion for all patients; versus subgroup (2): automated broaching with automated stem insertion ONLY if a cushion of cancellous bone separated the broach from the calcar, otherwise the stem was placed manually. Continuous and categorical variables were analyzed with Student's t-test and Fisher's exact test, respectively. Results: Seventeen calcar fractures occurred intraoperatively (1.1 %). Only two fractures occurred during automated broaching (0.1 %), while fifteen occurred during final stem impaction (0.9 %) (p = 0.007). Four calcar fractures (1.4 %) occurred in subgroup 1, compared to two in subgroup 2 (0.6 %) (p = 0.28). Conclusions: Our study found a calcar fracture incidence of 1.1 % using automated impaction, consistent with historically reported rates of 0.4-3.7 %. We found that calcar fractures are more likely to occur during stem insertion than during femoral broaching. We recommend that if any part of the final broach is in direct contact with the calcar, the final stem should be impacted manually to minimize fracture risk.

Countermovement jump and vertical hop demonstrate braking/deceleration and performance alterations after ACL reconstruction with BMA, DBM, and suture tape augmentation.

Objectives: This study evaluated countermovement jump and Single Leg Jump measures to identify landing measures that best distinguish a novel Anterior Cruciate Ligament reconstruction technique using bone marrow aspirate, demineralized bone matrix, and suture tape augmentation patients from controls. The secondary objective assessed performance differences between operated and non-operated limbs post-reconstruction. The hypothesis was that novel Anterior Cruciate Ligament reconstruction patients at return to sport would not differ from controls during landing and that the operated limb's performance would not differ from the unoperated limb. Methods: The study included 31 patients with the novel reconstruction technique matched with controls in a 1:10 ratio based on age, sex, weight, and height. Both groups underwent screening and were compared during a Countermovement Jump. Using a Sparta Science Force Platform, each patient's unoperated and operated limbs were also compared for Single Leg Jump post-op (6.5 months). Results: Test patients showed no difference in center of pressure during landing of both jumps compared to controls (P=0.27) and the uninvolved limb (P=0.26). Test patients exhibited increased braking impulse relative to the uninvolved limb during Single Leg Jump (P<0.001). Deceleration upon landing of Countermovement Jump was also increased compared to controls (P<0.001). Test patients demonstrated slower concentric time during a Countermovement Jump compared to controls (P=0.03) and significantly slower compared to the uninjured leg (P<0.001). Countermovement Jump height was decreased compared to controls (P<0.001). Single-leg jump height was decreased in the injured limb compared to the uninjured limb (P<0.001). Conclusions: Test patients did not show significant differences in landing motion compared to controls or the uninvolved leg. However, power and performance alterations were evident at Return to Sport after reconstruction. Although these results are quite promising, they may be too preliminary to draw definitive conclusions. Double and single-legged assessments should be considered in return-to-sport decision-making.

Corneal stromal structure replicating humanized hydrogel patch for sutureless repair of deep anterior-corneal defect.

A critical shortage of donor corneas exists worldwide. Hydrogel patches with a biological architecture and functions that simulate those of native corneas have garnered considerable attention. This study introduces a stromal structure replicating corneal patch (SRCP) composed of a decellularized cornea-templated nanotubular skeleton, recombinant human collagen, and methacrylated gelatin, exhibiting a similar ultrastructure and transmittance (above 80 %) to natural cornea. The SRCP is superior to the conventional recombinant human collagen patch in terms of biomechanical properties and resistance to enzymatic degradation. Additionally, SRCP promotes corneal epithelial and stromal cell migration while preventing the trans-differentiation of stromal cells into myofibroblasts. When applied to an ocular surface (37 °C), SRCP releases methacrylated gelatin, which robustly binds SRCP to the corneal stroma after activation by 405 nm light. Compared to gelatin-based photocurable hydrogel, the SRCP better supports the restoration of normal corneal curvature and withstands deformation under an elevated intraocular pressure (100 mmHg). In an in vivo deep anterior-corneal defect model, SRCP facilitated epithelial healing and vision recovery within 2 weeks, maintained graft structural stability, and inhibited stromal scarring at 4 weeks post-operation. The ideal performance of the SRCP makes it a promising humanized corneal equivalent for sutureless clinical applications.

Clinical outcomes and significance of postoperative ultrasound biomicroscopy in patients with Boston type 1 keratoprosthesis

ABSTRACT Purpose: To determine the clinical outcomes in patients after type 1 Boston keratoprosthesis surgery and the significance of ultrasound biomicroscopy imaging for postoperative follow-up. Methods: This retrospective analysis included 20 eyes of 19 patients who underwent corneal transplantation with type 1 Boston keratoprosthesis between April 2014 and December 2021. Data on patient demographics, preoperative diagnosis, visual acuity, and postoperative clinical findings were analyzed. Results: Type 1 Boston keratoprosthesis implantation resulted in intermediate- and long-term positive outcomes. However, blindness and other serious complications such as glaucoma, retroprosthetic membrane formation, endophthalmitis, or retinal detachment also occurred. The use of ultrasound biomicroscopy imaging allowed for better evaluation of the back of the titanium plate, anterior segment structures, and the relationship of the prosthesis with surrounding tissues, which provided valuable postoperative information. Conclusion: Regular lifetime monitoring and treatment are necessary in patients who undergo Boston type 1 keratoprosthesis implantation for high-risk corneal transplantation. ultrasound biomicroscopy imaging can be a valuable imaging technique for the evaluation of patients with Boston type 1 keratoprosthesis, providing important information on anterior segment anatomy and potential complications. Further studies and consensus on postoperative follow-up protocols are required to optimize the management of patients with Boston type 1 keratoprosthesis.

Associations of ocular anterior segment structures with sex and age: the Yamagata study (Funagata).

PURPOSE: To investigate the associations of tomographic parameters in anterior segment optical coherence tomography (AS-OCT) with sex and age in a cohort study. STUDY DESIGN: A cohort design. MATERIALS AND METHODS: AS-OCT data from 391 Japanese participants aged ≥ 35 years were obtained using swept-source OCT. In the cornea, the keratometric power at the flat (Kf) and steep (Ks) meridians, maximum keratometric power (Kmax), keratometric cylinder, spherical power, regular astigmatism, asymmetry, higher-order irregularity (HOI) from the anterior and posterior surfaces, and the central and thinnest corneal thicknesses were evaluated. Also, anterior chamber depth (ACD), lens thickness, crystalline lens rise (CLR), and nasal and temporal angle opening distances at 500 µm from the scleral spur (AOD500) were assessed. Sex differences and age-related changes were analyzed. RESULTS: Women exhibited higher anterior Kf, Ks, and Kmax and lower posterior Kf, Ks, and Kmax than men. The ACD and nasal/temporal AOD500 were shorter in women than in men. The CLR was higher in women, whereas the lens thickness did not differ between the sexes, indicating a more anteriorly positioned lens in women. Age-related changes included increased anterior/posterior HOI, increased lens thickness and CLR resulting in decreased ACD and AOD500. CONCLUSION: This study reveals sex-related differences in corneal shape, anterior chamber conformation, and lens position, as well as age-related changes in tomographic parameters. ACD, CLR, nasal and temporal AOD500 showed significant sex differences in the 50-70 s, whereas lens thickness showed no difference.

Anterior extrapelvic approaches to the acetabulum.

Anterior approaches to the acetabulum can be distinguished into extrapelvic, intrapelvic and combined extrapelvic and intrapelvic approaches. Historically, the extrapelvic ilioinguinal approach was introduced in the French, English and German literature during the late 60s and became gradually the Gold-standard in treating anterior acetabular fractures. In the meantime, the intrapelvic approach, introduced by the Helsinki group, is favored by many surgeons with ongoing interest allowing direct antero-medial access to the true pelvis below the linea terminalis, to the quadrilateral plate and medial side of the posterior column. More recently, more supero-medial approaches, allowing access to the large and true pelvis have been developed, e.g. the Pararectus approach. The historical development, the value and approach-related results of the ilioinguinal approach are analyzed and discussed.

Revision ACL reconstruction, but not bilateral ACL reconstruction, is associated with clinically relevant inferior subjective knee function compared with primary ACL reconstruction: A comparative analysis of 6831 patients.

PURPOSE: To evaluate and compare the subjective knee function in patients undergoing revision and bilateral anterior cruciate ligament (ACL) reconstruction (ACLR) with those undergoing primary ACLR in a large cohort. METHODS: Patients without concomitant ligament injuries who underwent primary, revision or bilateral ACLR at the Capio Artro Clinic, Stockholm, Sweden, between 2005 and 2018 were identified. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2 and 5 years postoperatively from the Swedish National Knee Ligament Registry. Patients who underwent revision and bilateral ACLR were compared with those who underwent primary ACLR (control group) using Student's t test. RESULTS: A total of 6831 patients (6102 with primary ACLRs, 343 with revision ACLRs and 386 with bilateral ACLRs) were included. Preoperatively, there were significant but nonclinically relevant differences in favour of the revision ACLR group for KOOS Symptoms, Pain, Activities of Daily Living (ADL) and Sport/Rec subscale scores compared with the primary ACLR group. Postoperatively, except for the 1-year Symptoms and ADL subscales, the revision ACLR group reported significantly lower scores on all KOOS subscales than the primary ACLR group, with clinically relevant differences (>8-10 points) for the 1-, 2- and 5-year Sport/Rec and Quality of Life (QOL) subscales. The bilateral ACLR group reported significantly, but not clinically relevant, inferior scores on the 1-year Symptoms and QOL subscales and the 5-year Sport/Rec and QOL subscales compared with the primary ACLR group. CONCLUSIONS: Revision ACLR, but not bilateral ACLR, was associated with clinically relevant inferior subjective knee function compared with primary ACLR. It is important to counsel patients regarding their future subjective knee function after repeated ACLR. Compared to primary ACLR, inferior subjective results should be expected after revision ACLR, but not after bilateral ACLR. LEVEL OF EVIDENCE: Level III.

More is Less: Image Enhancement Technology Reduces Radiation Exposure During Anterior Lumber Interbody Fusion.

BACKGROUND CONTEXT: Fluoroscopy and radiation exposure occur during anterior lumbar interbody fusion (ALIF). Image enhancement technology is available that can potentially reduce radiation exposure. PURPOSE: The purpose of this study is to evaluate radiation exposure and fluoroscopy times comparing standard fluoroscopy (FL) with a low dose image enhancement platform (LD). STUDY DESIGN: Retrospective review of prospectively maintained database PATIENT SAMPLE: Consecutive patients undergoing ALIF with either standard fluoroscopy or low dose image enhancement technology OUTCOME MEASURES: Radiation dispersion and fluoroscopy times in ALIF patients with standard fluoroscopy and low dose image enhancement technology METHODS: A retrospective review of a prospective database on consecutive patients who have undergone ALIF, stratified into two groups: subjects with standard fluoroscopy (FL), and low dose fluoroscopy with image enhancement technology (LD). RESULTS: A total of 487 ALIF patients were included (FL: 372 vs LD: 115). LD patients were significantly older (66 vs 60 years), with more deformity cases (28% vs 12%), and less degenerative cases (71% vs 87%), all p<0.05; no differences in sex, BMI, or the number of levels operated on between groups. Fluoroscopy time (sec) was significantly higher in LD (51.4 vs 45.5), with a statistically significant reduction in radiation (mGy) compared to FL (23.3 vs 48.2), both p<0.05. Furthermore, the results showed that radiation dispersion is increasingly reduced as fluoroscopy time increases in LD compared to FL (12%, 56%, and 65% reduction in radiation dispersion for fluoroscopy time < 30 sec, between 30 to 60 sec, and > 60 sec, respectively). CONCLUSIONS: The use of low dose fluoroscopy with image enhancement technology significantly reduces the cumulative dose of radiation during ALIF compared to standard dose fluoroscopy. Also, radiation dispersion increasingly decreases as fluoroscopy time increases using low dose image enhancement technology. Low dose image enhancement technology improves the safety profile of ALIF for patients and operating room staff.

Spine surgical site infection outcome with preoperative application of a pre-saturated 10% povidone-iodine nasal decolonization product in a 32-bed surgical hospital.

BACKGROUND: To pursue an irreducible minimum overall surgical site infection (SSI) rate, a 32-bed surgical hospital employed an outside consultant and performed sterile processing and surgery internal audits: no obvious improvements were identified. A ten-year review determined 70% of SSI's were spine procedure patients. After a nasal decolonization product literature review an intervention was implemented. The purpose of this study was to assess if the intervention impacted spine SSI rates. METHODS: A 36-month implementation science study was conducted. The 18-month intervention was immediate preoperative application of a manufactured pre-saturated 10% povidone iodine nasal decolonization product in spine surgery patients, with monthly product application documentation surveillance feedback to the preoperative staff. Chi-square test was used to determine the difference in types of spine SSI surgery rates pre and post intervention. RESULTS: Overall spine SSI decreased 35.7% (p=0.04) with 58.7% reduction in superficial incisional SSI (p=0.02). The 16.1% decline in deep incisional SSI was not significant (p=0.29). CONCLUSION: Within this hospital, conducting 7,576 surgical spine procedures over 36-months, with the immediate preoperative application of a pre-saturated ten percent povidone-iodine nasal decolonization product, the only intervention in SSI prevention protocol, produced a statistically significant decrease in spine patient SSI rate percent.

Surgical Management and Rehabilitation of Ultra-Low Velocity Bilateral Multi-Ligament Knee Injury: A Case Report.

Bilateral low-velocity multi-ligament knee Injury (MLKI) is a rare injury increasing in prevalence along with obesity. Early surgical intervention is indicated to improve long-term outcomes. We describe the surgical and postoperative management of a bilateral MLKI. The patient underwent staged multi-ligament knee reconstruction 17 and 35 days after injury. Return to light-duty was achieved 4 weeks following each procedure and progression to exercise at 6 months. The patient is 2 year postoperative and returned to all activity without complaint. We describe successful surgical and rehabilitation management, which encourages early surgery and rehabilitation strategies to improve long-term outcomes.

Utility of doppler ultrasound in early-onset neonatal sepsis: A case-control study.

BACKGROUND: Early-onset sepsis is one of the leading causes of neonatal morbidity and mortality worldwide and timely diagnosis is, therefore, of paramount importance. As there is a lack of literature regarding early alteration of the cerebral blood flow (CBF) in neonatal sepsis, our study aimed to appraise changes in the CBF velocities and Doppler indices in neonates with early-onset neonatal sepsis (EONS) and to assess its diagnostic accuracy. METHODS: A total of 99 neonates were recruited in the study; 56 neonates with EONS, and the age-matched 43 neonates without any manifestations of sepsis. A Transcranial Doppler examination and cerebral hemodynamics were assessed in neonates during the first seventy-two hours of life. Doppler indices and CBFV were measured in the anterior cerebral artery (ACA), and middle cerebral artery (MCA), of either side. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. RESULTS: A significantly lower resistance in Resistivity (RI) and Pulsatility (PI) indices, a significant high end-diastolic velocity (EDV), and relatively higher peak systolic velocity (PSV) in both ACA and MCA have been documented within 72 hours of birth in neonates with EONS compared to the control group of neonates without sepsis. CONCLUSION: Our Study revealed that assessment of CBF at early hours of birth by Transcranial Doppler examination showed alteration in cerebral hemodynamics in neonates with EONS with an increase in the CBF and a decrease in the resistance. It can be adopted as a bedside, noninvasive tool with immediate diagnostic value.

MRI-based endplate bone quality score independently predicts cage subsidence after anterior cervical corpectomy fusion.

BACKGROUND: To reduce the amount of radiation that patients receive during surgery, surgeons can evaluate the quality of the bone prior to surgery using computed tomography (CT) or dual-energy X-ray absorptiometry. Recently, lumbar spine vertebral bone quality has been evaluated using an MRI-based scoring system. However, few studies have investigated the connection between cage subsidence in patients following cervical interbody fusion and site-specific MRI bone evaluation. It is unknown how cage subsidence following anterior cervical corpectomy decompression and fusion is related to MRI-based endplate bone quality assessment. PURPOSE: To create a similar MRI-based cervical spine scoring system (C-EBQ) and to investigate the predictive value of the MRI cervical endplate bone quality (C-EBQ) score for cage subsidence after ACCF. METHODS: The patients' demographic, surgical, and radiological data were collected. Cage subsidence was defined as fusion segment height loss ≥ 3 mm. Multivariate logistic regression models were developed to determine correlations between potential risk factors and subsidence, and simple linear regression analyses of statistically significant indicators were performed. RESULTS: Among the patients who underwent single-level ACCF, 72 met the requirements for inclusion. The C-VBQ scores also improved from 2.28 ± 0.12, indicating no subsidence, to 3.27 ± 0.35, which indicated subsidence, and the C-EBQ scores improved in both the nonsubsidence group (1.95 ± 0.80) and the subsidence group (2.38 ± 0.54). There was a statistically significant difference (p < 0.05) among the groups. Higher C-EBQ scores were strongly correlated with subsidence in the multivariate analysis (odds ratio [OR] = 17.249, 95% CI = 2.269 to 7.537, P < 0.001), and the C-VBQ score was the major independent predictor of subsidence following ACCF ([OR] = 4.752, 95% CI = 3.824 to 8.781, P < 0.05). The C-EBQ score outperformed the C-VBQ score (75.6%) in terms of predictive accuracy, with a ROC curve indicating an 89.4% score. CONCLUSIONS: After ACCF, cage subsidence was strongly correlated with higher C-EBQ scores on preoperative MRI. Assessing C-EBQ before ACCF may be a useful way to estimate the likelihood of postoperative subsidence.

Stress Analysis of Periodontal Tissue in en Masse Retraction With Integration of Maxillary Anterior Teeth: A Three-Dimensional Finite Element Method Study.

OBJECTIVE: To simulate the en masse traction technique with the integration (EMTI) of six maxillary anterior teeth using a finite element model (FEM) and explore various protocols for maxillary protrusion. The study aimed to investigate root displacement and stress distribution in the periodontal ligament (PDL) by varying the retraction position and direction of EMTI applied to the maxillary anterior teeth. No actual participants were involved. MATERIALS AND METHODS: The FEM model included six teeth (central and lateral incisors and canines) with a PDL thickness of 0.3 mm. The model encompassing the alveolar bone (ALB) and EMTI had 180,528 elements and 47,836 nodes. The EMTI integrated six anterior teeth via a 0.9-mm-diameter stainless steel lingual wire, equipped with three moment arms extending toward the root apex: one midline (central arm) and two distal to the canines (lateral arms). The position and direction of the traction force applied to the three moment arms of the EMTI were varied to assess crown and apex displacement, as well as PDL stress. RESULTS: Lingual tipping was consistent across all protocols, emphasizing controlled incisor tipping. The application of horizontal traction at 10 mm and traction at 7 mm from the central and lateral arms of the EMTI, respectively, demonstrated the most uniform stress distribution across the PDL of all six anterior teeth. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The FEM analysis results suggest that the new EMTI method, which retracts the maxillary anterior teeth as a unit, is effective for tooth movement and PDL stress distribution. The EMTI technique, with its specific traction protocols and emphasis on controlled tipping, appears to be a promising approach for addressing maxillary protrusions.

Intra-rater and inter-rater reliability of robotic arthrometer DYNEELAX®.

Purpose: The purpose of our study was to test the intra-rater and inter-rater reliability of the DYNEELAX® arthrometer in healthy subjects. Since rotational laxity will be measured for the first time in humans, indications for normative values will also be presented. Methods: Knee anterior laxity and rotational laxity using a DYNEELAX® arthrometer were assessed in 73 subjects (39 females and 34 males). An intraclass correlation coefficient was calculated to evaluate the intra-rater and inter-rater reliability of the DYNEELAX®. Results: An intraclass correlation coefficient for intra-rater reliability ranges from 0.631 (95% confidence interval; [CI]: 0.47-0.75) to 0.699 (95% CI: 0.56-0.80) and from 0.916 (95% CI: 0.87-0.95) to 0.94 (95% CI: 0.91-0.96) for anterior knee laxity and rotational knee laxity, respectively. An intraclass correlation coefficient for inter-rater reliability ranges from 0.578 (95% CI: 0.40-0.71) to 0.646 (95% CI: 0.44-0.78) and from 0.822 (95% CI: 0.57-0.91) to 0.933 (95% CI: 0.89-0.96) for anterior knee laxity and rotational knee laxity, respectively. Conclusions: The DYNEELAX® arthrometer has good to excellent intra-rater and inter-rater reliability for rotational knee laxity and moderate intra-rater reliability for anterior knee laxity in healthy subjects. Future studies should investigate the clinical significance of anterior and rotational laxity measured with the DYNEELAX® arthrometer in patients with knee pathology, as both laxities are critical for assessing the integrity of the intra-articular structures of the knee in clinical practice. Level of evidence: Level IV.

Coil Embolization of a Ruptured Anterior Spinal Artery Aneurysm Associated with Spinal Cord Arteriovenous Malformation.

The present report describes a patient with spinal cord arteriovenous malformation (AVM) and an associated anterior spinal artery aneurysm presenting with subarachnoid hemorrhage. Diagnostic spinal angiography revealed an intramedullary AVM, located at the T10-T11 level, and a prenidal saccular aneurysm at the junction of the radiculomedullary artery and the anterior spinal axis, fed by the right T8 segmental artery. The patient underwent successful selective coil embolization of the aneurysm. Follow-up angiography 3 months postoperatively showed no recurrence of the aneurysm.

Distribution characteristics of stress on the vertebrae following different ranges of excision during Modified Anterior Cervical Discectomy and Fusion: A correlation study based on finite element analysis.

BACKGROUND: Modified Anterior Cervical Discectomy and Fusion with specific resection ranges is an effective surgical method for the treatment of focal ossification of the posterior longitudinal ligament (OPLL). Herein, we compare and analyse the static stress area distribution by performing different cuts on an original ideal finite element model. METHOD: A total of 96 groups of finite element models of the C4-C6 cervical spine with different vertebral segmentation ranges (width: 1-12 mm, height: 1-8 mm) were established. The same pressure direction and size were applied to observe the size and distribution area of stress following various ranges of excision of the C5 vertebral body. RESULTS: Different cutting areas had similar stress aggregation points. As the contact area decreased, the stress and the bearing above area increased. The correlation of stress area variation was highest between the 1-2 MPa and 6 MPa-Max regions (Rho = - 0.975). In the surface visualisation model fitting, the width and height were of different ratios in different stress regions. The model with the best fitting degree was the 1-2 MPa group, and the equation fitting (Rho = 0.966) was as follows: Area = 908.80 - 25.92 × Width + 2.71 × Height. CONCLUSION: Modified Anterior Cervical Discectomy and Fusion with different resection ranges exhibited different stress areas. In a specific resection range of the cervical spine (1-12 mm, 0-8 mm), area conversion occurred at a threshold of 4 MPa. Additionally, the stress was concentrated at the contact points between the vertebral body and the rigid fixator.

Assessing the Impact of Psychological Readiness on Performance and Symmetry in Functional Testing After ACL Reconstruction in Pediatric and Adolescent Patients.

Background: Readiness for return to sports involves both physical and psychological aspects of recovery; however, the relationship between psychological and physical variables after anterior cruciate ligament (ACL) reconstruction (ACLR) is poorly understood. Hypothesis: ACLR patients with a higher psychological readiness would demonstrate better functional testing results at 6 months. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Participants were evaluated at 6 months after ACLR with various patient-reported outcome metrics: Hospital for Special Surgery Pediatric Functional Activity Brief Scale, pediatric or adult International Knee Documentation Committee Questionnaire (IKDC), Patient-Reported Outcomes Measurement Information System (PROMIS) - Psychological Stress Experience and ACL - Return to Sport After Injury (ACL-RSI) scale. Functional testing included quadriceps, hamstrings, and gluteal strength testing; Y-balance test; single-leg single hop, crossover hop, and triple hop tests; and timed 6-m hop test. Pearson correlation coefficient and multivariable regression were used to determine associations between the limb symmetry index (LSI) on functional testing and patient-reported outcomes. Those with LSI deficits <20% (better performance) were compared with those with deficits >20% (worse performance). Results: A total of 229 participants (89 male, 140 female) with a median age of 17 years (range, 10.3-30.6 years) were enrolled. IKDC had a moderate negative correlation with PROMIS - Psychological Stress Experience (r = -0.39; 95% CI = -0.49, -0.27; P < .001) and a moderate positive correlation with ACL-RSI (r = 0.55; 95% CI = 0.46, 0.64; P < .001). A total of 151 patients completed functional testing. ACL-RSI demonstrated a positive correlation with single-hop LSI (r = 0.21; 95% CI = 0.05, 0.35; P = .01) and timed 6-m hop (r = 0.28; 95% CI, 0.42; P = .001). When adjusting for sex, age, and graft type, patients who had <20% deficit on the single-hop test scored 16.6 points higher on ACL-RSI (P = .001), and those with <20% deficit on crossover hop testing scored a mean 13.9 points higher on ACL-RSI (P = .04). Conclusion: Higher psychological readiness for return to sport was associated with better performance and greater symmetry on hop testing 6 months after ACLR, suggesting a potential link between physical and psychological recovery.

Clinical Manifestations and Outcomes of Ocular Graft Versus Host Disease following Allogeneic Stem Cell Transplantation.

Purpose: To evaluate clinical presentation of chronic ocular graft-versus-host disease (GVHD), laterality of presentation, and longitudinal changes in patients undergoing allogeneic stem cell transplantation. Methods: This is a retrospective longitudinal analysis of 60 eyes from 30 patients who had undergone hematopoietic stem cell transplantation. Demographic characteristics, clinical history, comorbidities, and other organ involvements were taken into account for analysis. We also undertook complete evaluation of the eyes, including cornea and anterior segment, posterior segment, Schirmer test, tear break-up time, ocular surface disease index, and intraocular pressure. Results: The mean age of the patients was 34.3 ± 11 years. The mean time for the diagnosis of ocular GVHD was 232.8 days (95% CI: 153.6, 311.9). The common findings at the first visit were bilateral blepharitis (n = 5, 17%), meibomitis (n = 4, 13%), and conjunctival congestion (n = 3, 10%). While bilateral cataract was present in one (3%) patient at the first visit, at 18 months, five (17%) patients had bilateral cataract and one (3%) patient had unilateral cataract. Grade 1 (n = 17), grade 2 (n = 9), and grade 3 (n = 4) superficial punctate epithelial erosions (SPEEs) were also observed at the first visit. However, SPEEs were seen in only 11 eyes at 18 months; all of these cases were grade 1 SPEEs. Long-term findings included cataract, telangiectasia, blepharospasm, conjunctival congestion, grade 1 SPEEs, corneal filaments, and tear film debris. Conclusion: Although the initial presentations were SPEEs, meibomitis, blepharitis, and conjunctival congestion, these inflammatory conditions were reduced over time with proper management. However, there was an increase in the proportion of patients with cataract. It is important to regularly monitor these patients in order to identify and manage the initial as well as the late ocular manifestations of chronic GVHD.