Most elite athletes return to preinjury competitive activity after surgical treatment for medial malleolus stress fractures.

PURPOSE: To provide return-to-performance outcomes after surgical treatment for medial malleolus stress fractures in the elite athlete. Additionally, to describe an individualised surgical approach in the management of medial malleolus stress fractures. METHODS: Five athletes (six ankles) underwent surgical treatment for a medial malleolus stress fracture. The surgical technique was based on the extent of the fracture line in steps with first arthroscopic debridement of bony spurs, microfracturing of the fracture line and screw fixation. Return-to-performance data included time to return to sport-specific training, normal training, first competitive activity, performance and the return-to-performance rate. RESULTS: Patients returned to sport-specific training at a median of 10 weeks. They started normal training at 16 weeks postoperatively and returned to their first competitive activity after 19 weeks. All patients had bony spurs on the distal tibia which were arthroscopically debrided. One patient received arthroscopic debridement of bony spurs alone. Four patients received additional microfracturing of the fracture line and three patients received screw fixation. All patients achieved clinical and radiographic union on follow-up computed tomography scan at 3 months postsurgery. At latest follow-up, no refractures nor hardware complications, nor any other complications were observed. CONCLUSION: Arthroscopic debridement of bony spurs, debridement and microfracturing of the fracture line and screw fixation are all viable surgical tools in the management of medial malleolus stress fractures in elite athletes. The surgical approach containing these options should be tailored to the individual athlete based on the fracture line in the sagittal plane. While most athletes return to full competitive activity in 3-4 months, time to self-reported return to full performance is often much longer. LEVEL OF EVIDENCE: Level IV.

No difference between 5 and 6 weeks of non-weight bearing after osteochondral grafts for medial osteochondral defects of the talus with medial malleolar osteotomy.

PURPOSE: The present study aimed to compare the clinical outcomes and safety at a 1-year follow-up after 5 or 6 weeks of non-weight bearing after a Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for a medial osteochondral lesion of the talus (OLT). METHODS: A retrospective comparative case-control analysis of prospectively followed patients who underwent a TOPIC procedure with medial malleolus osteotomy was performed. Patients were matched in two groups with either 5 or 6 weeks of non-weight bearing. Clinical outcomes were evaluated using the Numeric Rating Scale (NRS) during walking, rest, running, and stairclimbing. Additionally, the Foot and Ankle Outcome Score (FAOS) and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were assessed. Moreover, radiology and complications were assessed. RESULTS: Eleven patients were included in the 5-week non-weight bearing group and 22 in the 6-week non-weight bearing group. No significant differences were found in any of the baseline variables. The NRS during walking in the 5-week group improved by 3.5 points and 4 points for the 6-week group (p = 0.58 at 1-year post-operatively). In addition, all other NRS scores, FAOS subscales and the AOFAS scores improved (all n.s. at 1 year follow-up). No significant differences in radiological (osteotomy union and cyst presence in the graft) were found. Moreover, no significant differences were found in terms of complications and reoperations. CONCLUSION: No statistical significant differences were found in terms of clinical, radiological and safety outcomes between 5 or 6 weeks of non-weight bearing following a TOPIC for a medial OLT. LEVEL OF EVIDENCE: Level III, Therapeutic.

The minimal important change is not a universal fixed value across diagnoses when using the FAOS and FAAM in patients undergoing elective foot and ankle surgery.

PURPOSE: This study aimed to calculate region and diagnosis-specific minimal important changes (MICs) of the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM) in patients requiring foot and ankle surgery and to assess their variability across different foot and ankle diagnoses. METHODS: The study used routinely collected data from patients undergoing elective foot and ankle surgery. Patients had been invited to complete the FAOS and FAAM preoperatively and at 3-6 months after surgery, along with two anchor questions encompassing change in pain and daily function. Patients were categorised according to region of pathology and subsequent diagnoses. MICs were calculated using predictive modelling (MICPRED) and receiver operating characteristic curve (MICROC) method and evaluated according to strict credibility criteria. RESULTS: Substantial variability of the MICs between forefoot and ankle/hindfoot region was observed, as well as among specific foot and ankle diagnoses, with MICPRED and MICROC values ranging from 7.8 to 25.5 points and 9.4 to 27.8, respectively. Despite differences between MICROC and MICPRED estimates, both calculation methods exhibited largely consistent patterns of variation across subgroups, with forefoot conditions systematically showing smaller MICs than ankle/hindfoot conditions. Most MICs demonstrated high credibility; however, the majority of the MICs for the FAOS symptoms subscale and forefoot conditions exhibited insufficient or low credibility. CONCLUSION: The MICs of the FAOS and FAAM vary across foot and ankle diagnoses in patients undergoing elective foot and ankle surgery and should not be used as a universal fixed value, but recognised as contextual parameters. This can help clinicians and researchers in more accurate interpretation of the FAOS and FAAM change scores. LEVEL OF EVIDENCE: Level IV.

Comparison of the early postoperative outcomes of cementless and cemented medial unicompartmental knee arthroplasty.

Aims: The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques. Methods: We analyzed 10,862 cementless and 7,917 cemented UKA cases enrolled in the Dutch Arthroplasty Registry, operated between 2017 and 2021. Pre- to postoperative change in outcomes at six and 12 months' follow-up were compared using mixed model analyses. Kaplan-Meier and Cox regression models were applied to quantify differences in implant survival. Adjustments were made for patient-specific variables and annual hospital volume. Results: Change from baseline in the Oxford Knee Score (OKS) and activity-related pain was comparable between groups. Adjustment for covariates demonstrated a minimally greater decrease in rest-related pain in the cemented group (ß = -0.09 (95% confidence interval (CI) -0.16 to -0.01)). Cementless fixation was associated with a higher probability of achieving an excellent OKS outcome (> 41 points) (adjusted odds ratio 1.2 (95% CI 1.1 to 1.3)). The likelihood of one-year implant survival was greater for cemented implants (adjusted hazard ratio (HR) 1.35 (95% CI 1.01 to 1.71)), with higher revision rates for periprosthetic fractures of cementless implants. During two to three years' follow-up, the likelihood of implant survival was non-significantly greater for cementless UKA (adjusted HR 0.64 (95% CI 0.40 to 1.04)), primarily due to increased revision rates for tibial loosening of cemented implants. Conclusion: Cementless and cemented medial UKA led to comparable improvement in physical function and pain reduction during the initial postoperative year, albeit with a greater likelihood of achieving excellent OKS outcomes after cementless UKA. Anticipated differences in early physical function and pain should not be a decisive factor in the choice of fixation technique. However, surgeons should consider the differences in short- and long-term implant survival when deciding which implant to use.

Ten-Year Survival Rate of 82% in 262 Cases of Arthroscopic Bone Marrow Stimulation for Osteochondral Lesions of the Talus.

BACKGROUND: The long-term sustainability of arthroscopic bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLT) remains a matter of debate. The primary aim of the present study was to assess the 10-year survival free from revision in ankles that had undergone arthroscopic BMS for an OLT. The secondary aim was to evaluate the influence of baseline patient and lesion characteristics on survival. METHODS: Patients who underwent arthroscopic BMS for a symptomatic OLT and had a minimum follow-up of 10 years were included to assess procedure survival. The primary outcome, the 10-year cumulative survival rate, was analyzed by the Kaplan-Meier survival method. Secondary outcomes were the median time to revision and the effects of baseline factors (lesion size, primary or non-primary lesion type, preoperative cysts, and obesity as defined by a body mass index [BMI] of ≥30 kg/m2) on survival, analyzed with a Cox regression model and reported using hazard ratios (HRs). RESULTS: The 262 included patients had a mean follow-up of 15.3 ± 4.8 years. The 10-year cumulative survival rate of the arthroscopic BMS procedures was 82% (95% confidence interval [CI]: 77% to 87%). At 15 years of follow-up, the cumulative survival rate was 82% (95% CI: 76% to 86%). The median time to revision was 2.4 years (interquartile range: 1.3 to 5.1 years). Of the baseline factors, obesity (HR: 3.0 [95% CI: 1.44 to 6.43], p < 0.01) was associated with decreased survival. Lesion size (HR: 0.9 [95% CI: 0.5 to 1.8], p = 0.8), non-primary lesion type (HR: 1.8 [95% CI: 0.9 to 3.4], p = 0.1), and the presence of preoperative cysts (HR: 1.0 [95% CI: 0.6 to 1.9], p = 0.9) were not significantly associated with survival. CONCLUSIONS: At a minimum follow-up of 10 years, the survival rate of arthroscopic BMS for OLT was 82%. At 15 and 20 years of follow-up, survival appeared to remain stable. Obesity (BMI ≥ 30 kg/m2) was associated with a higher likelihood of revision surgery. This risk factor should be incorporated into the treatment algorithm for OLT when counseling patients regarding surgery. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The mind matters: Psychological factors influence subjective outcomes following unicompartmental knee arthroplasty-A prospective study.

PURPOSE: This study aimed to investigate how psychological factors, including pain catastrophizing (PC), anxiety and depression affect preoperative and postoperative subjective outcomes in patients undergoing unicompartmental knee arthroplasty (UKA). METHODS: A prospective comparative study was performed among 150 patients undergoing medial or lateral UKA for isolated unicompartmental osteoarthritis. Patients were categorized based on their preoperative PC and Hospital Anxiety and Depression Scale, stratifying them into groups with PC, anxiety or depression, and those without these psychological factors. Patient-reported outcomes, including the Knee Injury and Osteoarthritis Outcome Score-Physical function Short form (KOOS-PS), 5-level EQ5D Visual Analogue Scale (EQ5D-VAS), Forgotten Joint Score (FJS) and Numeric Rating Scale for pain (NRS-pain) were compared between groups preoperatively and at 6-, 12-, and 24-month follow-up. RESULTS: At 24 months, PC patients had inferior outcomes in KOOS-PS (66.9 ± 16.5 vs. 77.6 ± 14.7, p = .008), EQ5D-VAS (63.5 ± 19.9 vs. 78.9 ± 20.1, p = .003) and FJS (73.7 ± 14.3 vs. 84.6 ± 13.8, p = .003). Anxiety was associated with inferior KOOS-PS (65.4 ± 15.2 vs. 78.2 ± 14.5, p = <.001), EQ5D-VAS (64.2 ± 23.2 vs. 79.3 ± 19.4, p = .002), FJS (75.7 ± 16.8 vs. 84.6 ± 13.4, p = .008) and NRS-pain (27.4 ± 24.6 vs. 13.7 ± 19.3, p = .023) at 24 months. Depression consistently resulted in inferior outcomes in KOOS-PS, EQ5D-VAS, FJS and NRS-pain across all follow-up assessments (p = <.05). Additionally, patients with anxiety and depression experienced longer length of hospital stay compared to those without these psychological factors (anxiety: 2.3 ± 2.3 vs. 0.8 ± 0.8 days, p = .006; depression: 2.3 ± 2.4 vs. 0.8 ± 0.8 days, p = .017). CONCLUSIONS: Preoperative PC, anxiety and depression are associated with inferior subjective outcomes both prior to and following UKA. Among these factors, depression seemed to exert the most substantial adverse impact on outcomes following UKA. Patients with anxiety and depression had an extended duration of hospitalization lasting over twice as long as patients without these psychological factors. It seems that inferior outcomes primarily stem from the suboptimal preoperative condition rather than an inherent inability to benefit from UKA. LEVEL OF EVIDENCE: Level II, prospective study.

Sex-specific analysis in patients undergoing Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for large osteochondral lesions of the talus.

PURPOSE: The purpose of the present study is to assess the gender-specific differences in the presentation and outcomes following Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) between male and female patients. METHODS: A prospective comparative analysis was performed comparing consecutive female and male patients having been treated by the press-fit TOPIC procedure. Clinical comparative assessment preoperatively and at 12 months of follow-up included determination of the Numeric Rating Scale (NRS) scores for pain during walking (primary outcome), at rest and during stair-climbing. The Foot and Ankle Outcome Score (FAOS) was also assessed. A computed tomography (CT) scan was performed for lesion size, morphology and localization determination preoperatively as well as 10-12 weeks postoperatively to assess the union of the osteotomy site and at 1 year postoperatively to assess consolidation of the graft as well as intra-graft cyst development. RESULTS: A total of 48 patients (30 women, 18 men) were eligible for inclusion. Both men and women demonstrated significant functional improvements postoperatively concerning the clinical outcomes with no significant differences between men and women (n.s.) except for a significantly greater improvement in postoperative FAOS pain scores in women. Men presented with OLTs significantly larger in both surface area (208 mm2 for males versus 155 mm2 for females, p < 0.05) as well as lesion volume (3.0 cm3 for males versus 1.8 cm3 for females, p < 0.05). At 1-year postoperatively, all patients showed graft consolidation. Cyst formation was present in 11 females (37% of the group) and 10 males (59% of the group), respectively (n.s.). CONCLUSION: Both males and females showed clinically relevant improvements in the clinical outcomes after undergoing the TOPIC procedure with significant differences in preoperative lesion size. The TOPIC procedure is a good treatment strategy for large OLTs in both men and women. LEVEL OF EVIDENCE: Level III, comparative prospective clinical cohort.

The Influence of Patient Characteristics and Social Determinants of Health on Postoperative Complications Following Achilles Tendon Rupture.

BACKGROUND: The influence of social determinants of health (SDH) on postoperative complications has been investigated in several studies, although correlation with Achilles tendon rupture (ATR) repair remains uninvestigated. SDH encompasses several factors, including insurance status and area-based measurements, including the Area Deprivation Index (ADI) and Social Vulnerability Index (SVI), which ranks neighborhoods by social disadvantage. This study investigated the correlation between patient demographics, SDH, and complications following ATR repair. METHODS: A retrospective cohort study was conducted on 521 patients who presented with acute ATR and met the inclusion criteria, including age ≥18 years, a minimum of 30-day follow-up, and repair within 28 days of rupture. We reviewed patient demographics, time to surgery (TTS), and postoperative complications, including venous thromboembolism (VTE), rerupture, surgical site infection (SSI), wound dehiscence, and sural nerve injury. SDH variables included race, smoking status, insurance status, level of education, ADI, and SVI. Univariate regression tested the correlation between complications and SDH indicators. Significant variables (P < .05) were included in a multivariate regression. RESULTS: Sixty-eight complications occurred in 59 patients (11.3%). Multivariate regression showed that a higher ADI, that is, socially deprived individuals, was associated with lower rates of VTE (OR = 0.41, P = .04). Higher body mass index (BMI) was associated with rerupture (OR = 8.73, P < .01). Male patients had lower rates of wound dehiscence (OR = 0.31, P = .03) and VTE (OR = 0.32, P = .02) compared with women. Longer TTS correlated with sural nerve injuries (OR = 2.23, P < .01) and shorter TTS with reruptures (OR = 0.02, P = .02). CONCLUSION: Some measures of SDH were associated with postoperative complications. Gender also may have an effect, with male sex associated with lower rates of wound dehiscence and VTE. BMI was associated with higher rates of reruptures and overall general complications. LEVEL OF EVIDENCE: Level IV, case series.

Wide-Awake Needle Arthroscopy of the Anterior Ankle: A Standardized Approach.

Over the years, possibilities in ankle arthroscopy have evolved from diagnostic inspection to complex interventional procedures. Further innovation may come from needle arthroscopy, which has improved substantially in image quality in recent years and can now be used for interventional procedures as well. We here present a standardized approach to wide-awake needle arthroscopy of the anterior ankle under local anesthesia. As new needle arthroscopic procedures of the ankle arise, this approach serves to help ensure safe, uniform, and beneficial adoption of this emergent technique.

Mid-term survival of the Optimys short stem: A prospective case series of 500 patients.

BACKGROUND: In recent years, there has been an increase in the number of total hip arthroplasty procedures in the younger patient population. This active group has higher expectations of their prosthesis in comparison to the older population, and there is a greater physical demand for the prosthesis. Short femoral stems were introduced to retain proximal bone stock and joint biomechanics and became more common to implant in this specific population. Currently, the long-term survival and functional outcomes of various short stems are still being investigated in different clinics. AIM: To determine the 5-year survival of the Optimys hip stem. METHODS: This was a prospective multicenter cohort study of 500 patients conducted in two hospitals in the Netherlands. All patients received the Optimys short stem (Mathys Ltd, Bettlach, Switzerland). The primary outcome measure was survival of the hip stem, with revision as the endpoint. The secondary outcome measurements included patient-reported outcome measures (PROMs). Kaplan-Meier analysis was used to calculate the 5-year survival rate. Log-minus-log transformation was performed to calculate the 95% confidence interval (95%CI). Mixed model analyses were performed to assess the course of the PROMs during the 1st 2 years after surgery. Analyses were modeled separately for the 1st and 2nd years to calculate the yearly change in PROMs during both follow-up periods with accompanying 95%CIs. RESULTS: The mean age of the total 500 patients was 62.3 years (standard deviation: 10.6) and 202 were male (40%). At a median follow-up of 5.5 years (interquartile range: 4.5-6.7), 7 patients were deceased and 6 revisions were registered, for infection (n = 3), subsidence (n = 2) and malposition (n = 1). This resulted in an overall 5-year survival of 98.8% (95%CI: 97.3-99.5). If infection was left out as reason for revision, a stem survival of 99.4% (95%CI: 98.1-99.8) was seen. Baseline questionnaires were completed by 471 patients (94%), 317 patients (63%) completed the 1-year follow-up questionnaires and 233 patients (47%) completed the 2-year follow-up. Both outcome measures significantly improved across all domains in the 1st year after the operation (P < 0.03 for all domains). In the 2nd year after surgery, no significant changes were observed in any domain in comparison to the 1-year follow-up. CONCLUSION: The Optimys stem has a 5-year survival of 98.8%. Patient-reported outcome measures increased significantly in the 1st postoperative year with stabilization at the 2-year follow-up.

Fixation of Osteochondral Lesions of the Talus: Indications, Techniques, Outcomes, and Pearls from the Amsterdam Perspective.

The treatment of osteochondral lesions of the talus (OLT) remains a topic of debate as no superior treatment has yet been identified. The current consensus is that it is crucial to incorporate lesion and patient characteristics into the treatment algorithm. One such lesion type is the OLT with a fragment, which may benefit from in situ fixation. Fixation preserves the native hyaline cartilage and offers a direct stabilization of the fragment with high-quality subchondral bone repair. This current concepts review describes the evidence-based clinical work-up, indications, surgical techniques, outcomes, and clinical pearls for fixation techniques of OLT from the Amsterdam perspective.

Ankle Cartilage: Chondral and Osteochondral Lesions: A Further Dive into the Incidence, Terminology, and the Cartilage Cascade.

The current concepts thoroughly highlight the ankle cartilage cascade focusing on the different stages and the different etiologic factors that can introduce a patient into the cascade. Moreover, the authors will provide the reader with a comprehensive overview of the types of lesions that may present as symptomatic, asymptomatic, and dangerous for progression into osteoarthritis, and the authors supply the reader with considerations and directions for future clinical implications and scientific endeavors.

Machine Learning Did Not Outperform Conventional Competing Risk Modeling to Predict Revision Arthroplasty.

BACKGROUND: Estimating the risk of revision after arthroplasty could inform patient and surgeon decision-making. However, there is a lack of well-performing prediction models assisting in this task, which may be due to current conventional modeling approaches such as traditional survivorship estimators (such as Kaplan-Meier) or competing risk estimators. Recent advances in machine learning survival analysis might improve decision support tools in this setting. Therefore, this study aimed to assess the performance of machine learning compared with that of conventional modeling to predict revision after arthroplasty. QUESTION/PURPOSE: Does machine learning perform better than traditional regression models for estimating the risk of revision for patients undergoing hip or knee arthroplasty? METHODS: Eleven datasets from published studies from the Dutch Arthroplasty Register reporting on factors associated with revision or survival after partial or total knee and hip arthroplasty between 2018 and 2022 were included in our study. The 11 datasets were observational registry studies, with a sample size ranging from 3038 to 218,214 procedures. We developed a set of time-to-event models for each dataset, leading to 11 comparisons. A set of predictors (factors associated with revision surgery) was identified based on the variables that were selected in the included studies. We assessed the predictive performance of two state-of-the-art statistical time-to-event models for 1-, 2-, and 3-year follow-up: a Fine and Gray model (which models the cumulative incidence of revision) and a cause-specific Cox model (which models the hazard of revision). These were compared with a machine-learning approach (a random survival forest model, which is a decision tree-based machine-learning algorithm for time-to-event analysis). Performance was assessed according to discriminative ability (time-dependent area under the receiver operating curve), calibration (slope and intercept), and overall prediction error (scaled Brier score). Discrimination, known as the area under the receiver operating characteristic curve, measures the model's ability to distinguish patients who achieved the outcomes from those who did not and ranges from 0.5 to 1.0, with 1.0 indicating the highest discrimination score and 0.50 the lowest. Calibration plots the predicted versus the observed probabilities; a perfect plot has an intercept of 0 and a slope of 1. The Brier score calculates a composite of discrimination and calibration, with 0 indicating perfect prediction and 1 the poorest. A scaled version of the Brier score, 1 - (model Brier score/null model Brier score), can be interpreted as the amount of overall prediction error. RESULTS: Using machine learning survivorship analysis, we found no differences between the competing risks estimator and traditional regression models for patients undergoing arthroplasty in terms of discriminative ability (patients who received a revision compared with those who did not). We found no consistent differences between the validated performance (time-dependent area under the receiver operating characteristic curve) of different modeling approaches because these values ranged between -0.04 and 0.03 across the 11 datasets (the time-dependent area under the receiver operating characteristic curve of the models across 11 datasets ranged between 0.52 to 0.68). In addition, the calibration metrics and scaled Brier scores produced comparable estimates, showing no advantage of machine learning over traditional regression models. CONCLUSION: Machine learning did not outperform traditional regression models. CLINICAL RELEVANCE: Neither machine learning modeling nor traditional regression methods were sufficiently accurate in order to offer prognostic information when predicting revision arthroplasty. The benefit of these modeling approaches may be limited in this context.

Progression of partial to complete ruptures of the Achilles tendon during rehabilitation: A study using a finite element model.

Substantial research on complete Achilles tendon ruptures is available, but guidance on partial ruptures is comparatively sparse. Conservative management is considered acceptable in partial tendon ruptures affecting less than 50% of the tendon's width, but supporting experimental evidence is currently lacking. Using a previously validated finite element model of the Achilles tendon, this study aimed to assess whether loading conditions simulating an early functional rehabilitation protocol could elicit progression to a complete rupture in partial ruptures of varying severity. In silico tendon rupture simulations were performed to locate the most likely rupture site for least, moderate, and extreme subtendon twist configurations. These three models were split at the corresponding rupture site and two sets of partial ruptures were created for each, starting from the medial and lateral sides, and ranging from 10% to 50% loss of continuity. Simulations were conducted with material parameters from healthy and tendinopathic tendons. Partial ruptures were considered to progress if the volume of elements showing a maximum principal strain above 10% exceeded 3 mm3 . To assess whether the tendinopathic tendons typical geometric characteristics could compensate for the inferior material properties found in tendinopathy, an additional model with increased cross-sectional area in the free tendon region was developed. Progression to complete ruptures occurred even with less than a 50% loss of continuity, regardless of subtendon twisting, and material parameters. The tendinopathic tendon model with increased cross-sectional area showed similar results. These findings suggest the current criteria for surgical treatment of partial ruptures should be reconsidered. Statement of clinical significance: The clinical significance and most appropriate treatment of partial ruptures of the Achilles tendon is unclear. Despite the widespread use of the "50% rule" in treatment decisions of partial tendon ruptures, experimental evidence supporting it is missing. The present study provides new data, from a validated aponeurotic and free Achilles tendon finite element model, showing that partial ruptures may progress to complete ruptures under loading conditions elicited from functional rehabilitation protocols, even for partial ruptures affecting less than 50% of the tendon's width. Under these novel findings, the current criteria for surgical treatment of partial ruptures should be reconsidered.

Minimal but potentially clinically relevant anteroinferior position of the humeral head following traumatic anterior shoulder dislocations: A 3D-CT analysis.

In unstable shoulders, excessive anteroinferior position of the humeral head relative to the glenoid can lead to a dislocation. Measuring humeral head position could therefore be valuable in quantifying shoulder laxity. The aim of this study was to measure (1) position of the humeral head relative to the glenoid and (2) joint space thickness during passive motion in unstable shoulders caused by traumatic anterior dislocations and in contralateral uninjured shoulders. A prospective cross-sectional CT-study was performed in patients with unilateral anterior shoulder instability. Patients underwent CT scanning of both injured and uninjured side in supine position (0° abduction and 0° external rotation) and in 60°, 90°, and 120° of abduction with 90° of external rotation without an external load. Subsequently, 3D virtual models were created of the humerus and the scapula to create a glenoid coordinate system to identify poster-anterior, inferior-superior, and lateral-medial position of the humeral head relative to the glenoid. Joint space thickness was defined as the average distance between the subchondral bone surfaces of the humeral head and glenoid. Fifteen consecutive patients were included. In supine position, the humeral head was positioned more anteriorly (p = 0.004), inferiorly (p = 0.019), and laterally (p = 0.021) in the injured compared to the uninjured shoulder. No differences were observed in any of the other positions. A joint-space thickness map, showing the bone-to-bone distances, identified the Hill-Sachs lesion footprint on the glenoid surface in external rotation and abduction, but no differences on average joint space thickness were observed in any position.

A Traumatic Impact Immediately Changes the Mechanical Properties of Articular Cartilage.

OBJECTIVE: To investigate whether and how a single traumatic impact changes the mechanical properties of talar articular cartilage. DESIGN: A marble was placed on the joint surface and a weight was dropped on both medial and lateral caprine talus to create a well-defined single focal impact. The mechanical properties of intact and impacted talar cartilage were measured with a micro-indenter. Elastic (storage) and viscous (loss) moduli were determined by oscillatory ramp and dynamic mechanical analysis protocols. RESULTS: We found significant differences between ankles and within the same ankle joint, with the medial talus having significantly higher storage- and loss moduli than the lateral talus. The storage- and loss moduli of intact articular cartilage increased with greater indentation depths. However, postimpact the storage- and loss moduli were significantly and consistently lower in all specimens indicating immediate posttraumatic damage. The deeper regions of talar cartilage were less affected by the impact than the more superficial regions. CONCLUSIONS: A single traumatic impact results in an immediate and significant decrease of storage- and loss moduli. Further research must focus on the development of non- or minimally invasive diagnostic tools to address the exact microdamage caused by the impact. We speculate that the traumatic impact damaged the collagen fibers that confine the water-binding proteoglycans and thereby decreasing the hydrostatic pressure of cartilage. As part of the treatment directly after a trauma, one could imagine a reduction or restriction of peak loads to prevent the progression of the cascade towards PTOA of the ankle joint.

Impaired hemodynamics of the patella in patients with patellofemoral pain: A case-control study.

Purpose: According to the homeostasis model, patellofemoral pain (PFP) arises as a consequence of disturbed homeostasis of anterior structures of the knee due to vascular insufficiency. Near-infrared spectroscopy (NIRS) allows to measure changes of concentrations (µmol/cm2) of (de)-oxygenated hemoglobine (HHb and O2Hb). The aim was to study differences in patellar hemodynamics between patients and healthy controls. Methods: Hemodynamics of patients (n = 30 [female = 20, age = 21.5, BMI = 22.9]) and controls (n = 30 (female = 18, age = 21.4, BMI = 22.4]) were evaluated for two activities ('Prolonged Sitting' and 'Stair Descent'). Blinding for health status was implemented. Results: During 'Prolonged Sitting', PFP patients exhibited smaller decreases in mean changes for HHb (PFP [M = -1.5 to -1.9], healthy controls [M = -2.0 to -2.3]) and O2Hb (PFP [M = -2.0 to -3.2], healthy controls [M = -3.4 to -4.1]). However, these differences were statistically non-significant (p = 0.14-0.82 and p = 0.056-0.18, respectively). Conversely, for 'Stair Descent', PFP patients showed statistically significant smaller decreases in mean changes for HHb (PFP [M = -1.9, SD = 1.8], healthy controls [M = -2.5, SD = 1.7], p = 0.043) and O2Hb (PFP [M = -3.2, SD = 3.2], healthy controls [M = -4.9, SD = 2.7], p = 0.004). Conclusions: The differences suggest potential impairment in patellar hemodynamics in PFP patients, providing support for the homeostasis model. Evidence-based treatment strategies targeting patellar hemodynamics should be further refined and subjected to evaluation in clinical trials. Level of Evidence: Level III.

From technical to understandable: Artificial Intelligence Large Language Models improve the readability of knee radiology reports.

PURPOSE: The purpose of this study was to evaluate the effectiveness of an Artificial Intelligence-Large Language Model (AI-LLM) at improving the readability of knee radiology reports. METHODS: Reports of 100 knee X-rays, 100 knee computed tomography (CT) scans and 100 knee magnetic resonance imaging (MRI) scans were retrieved. The following prompt command was inserted into the AI-LLM: 'Explain this radiology report to a patient in layman's terms in the second person:[Report Text]'. The Flesch-Kincaid reading level (FKRL) score, Flesch reading ease (FRE) score and report length were calculated for the original radiology report and the AI-LLM generated report. Any 'hallucination' or inaccurate text produced by the AI-LLM-generated report was documented. RESULTS: Statistically significant improvements in mean FKRL scores in the AI-LLM generated X-ray report (12.7 ± 1.0-7.2 ± 0.6), CT report (13.4 ± 1.0-7.5 ± 0.5) and MRI report (13.5 ± 0.9-7.5 ± 0.6) were observed. Statistically significant improvements in mean FRE scores in the AI-LLM generated X-ray report (39.5 ± 7.5-76.8 ± 5.1), CT report (27.3 ± 5.9-73.1 ± 5.6) and MRI report (26.8 ± 6.4-73.4 ± 5.0) were observed. Superior FKRL scores and FRE scores were observed in the AI-LLM-generated X-ray report compared to the AI-LLM-generated CT report and MRI report, p < 0.001. The hallucination rates in the AI-LLM generated X-ray report, CT report and MRI report were 2%, 5% and 5%, respectively. CONCLUSIONS: This study highlights the promising use of AI-LLMs as an innovative, patient-centred strategy to improve the readability of knee radiology reports. The clinical relevance of this study is that an AI-LLM-generated knee radiology report may enhance patients' understanding of their imaging reports, potentially reducing the responder burden placed on the ordering physicians. However, due to the 'hallucinations' produced by the AI-LLM-generated report, the ordering physician must always engage in a collaborative discussion with the patient regarding both reports and the corresponding images. LEVEL OF EVIDENCE: Level IV.

Rotational Malalignment After Intramedullary Nailing of Tibial Shaft Fractures Is Predictable.

OBJECTIVES: Intramedullary nailing is the treatment of choice for most tibial shaft fractures (TSF). However, an iatrogenic pitfall may be rotational malalignment. The aim of this retrospective analysis was to determine predictors of rotational malalignment following intramedullary nailing of TSF. DESIGN: Retrospective study. SETTING: Single level 1 trauma center. PATIENT SELECTION CRITERIA: Patients who had a unilateral intramedullary nailing for TSF with a low-dose bilateral postoperative CT to assess rotational malalignment. OUTCOME MEASURES AND COMPARISONS: Bivariable analysis followed by multivariable analysis was then undertaken to assess for any independent predictors, such as fracture type/sight, surgeon experience, and side of fracture, predictive of rotational malalignment. RESULTS: In total, 154 patients (71% male, median age 37 years) were included in this study. Thirty-nine percent of variability in postoperative rotational malalignment could be explained using a model including (increased) tibial torsion of the noninjured side (mean [38.9 degrees ± 9.02 degrees] considered normal tibial torsion), side of tibial fracture, and spiral-type tibial fracture (R2 = 0.39, P ≤ 0.001, F = 31.40). In this model, there was a negative linear association between degrees of torsion on the noninjured side and rotational malalignment (-0.45, P < 0.001)-as baseline torsion increased from mean by 1 degree, malrotation in the opposite direction of 0.54 degrees seen. Positive linear associations between right-sided TSF and rotational malalignment (8.59 P < 0.001) as well as spiral fractures and rotational malalignment (5.03, P < 0.01) were seen. CONCLUSIONS: This study demonstrates that baseline reduced (internal) tibial torsion of the noninjured limb, spiral fractures, and right-sided TSF are predictive of postoperative external rotational malalignment. Conversely, increased baseline (external) tibial torsion of the noninjured limb and left-sided TSF are predictive of postoperative internal rotational malalignment. Surgeons may use this regression model preoperatively to predict what sort of postoperative rotational difference their patient may be prone to. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.