Prediction of transfusion risk after total knee arthroplasty: use of a machine learning algorithm.

INTRODUCTION: Total knee arthroplasty (TKA) carries a significant hemorrhagic risk, with a non-negligible rate of postoperative transfusions. The blood-sparing strategy has evolved to reduce blood loss after TKA by identifying the patient's risk factors preoperatively. In practice, a blood count is often performed postoperatively but rarely altering the patient's subsequent management. This study aimed to identify the preoperative variables associated with hemorrhagic risk, enabling the creation of a machine-learning model predictive of transfusion risk after total knee arthroplasty and the need for a complete blood count. HYPOTHESIS: Based on preoperative data, a powerful machine learning predictive model can be constructed to estimate the risk of transfusion after total knee arthroplasty. MATERIAL AND METHODS: This retrospective single-centre study included 774 total knee arthroplasties (TKA) operated between January 2020 and March 2023. Twenty-five preoperative variables were integrated into the machine learning model and filtered by a recursive feature elimination algorithm. The most predictive variables were selected and used to construct a gradient-boosting machine algorithm to define the overall postoperative transfusion risk model. Two groups were formed of patients transfused and not transfused after TKA. Odds ratios were determined, and the area under the curve evaluated the model's performance. RESULTS: Of the 774 TKA surgery patients, 100 were transfused postoperatively (12.9%). The machine learning predictive model included five variables: age, body mass index, tranexamic acid administration, preoperative hemoglobin level, and platelet count. The overall performance was good with an area under the curve of 0.97 [95% CI 0.921 - 1], sensitivity of 94.4% [95% CI 91.2 - 97.6], and specificity of 85.4% [95% CI 80.6 - 90.2]. The tool developed to assess the risk of blood transfusion after TKA is available at https://arthrorisk.com. CONCLUSION: The risk of postoperative transfusion after total knee arthroplasty can be predicted by a model that identifies patients at low, moderate, or high risk based on five preoperative variables. This machine learning tool is available on a web platform that is accessible to all, easy to use, and has a high prediction performance. The model aims to limit the need for routine check-ups, depending on the risk presented by the patient. LEVEL OF EVIDENCE: II; diagnostic study.

Risk prediction of kalaemia disturbance and acute kidney injury after total knee arthroplasty: use of a machine learning algorithm.

INTRODUCTION: Total knee arthroplasty (TKA) is a procedure associated with risks of electrolyte and kidney function disorders, which are rare but can lead to serious complications if not correctly identified. A routine check-up is very often carried out to assess the seric ionogram and kidney function after TKA, that rarely requires clinical intervention in the event of a disturbance. The aim of this study was to identify perioperative variables that would lead to the creation of a machine learning model predicting the risk of kalaemia disorders and/or acute kidney injury after total knee arthroplasty. HYPOTHESIS: A predictive model could be constructed to estimate the risk of kalaemia disorders and/or acute kidney injury after total knee arthroplasty. MATERIAL AND METHODS: This single-centre retrospective study included 774 total knee arthroplasties (TKA) operated on between January 2020 and March 2023. Twenty-five preoperative variables were incorporated into the machine learning model and filtered by a first algorithm. The most predictive variables selected were used to construct a second algorithm to define the overall risk model for postoperative kalaemia and/or acute kidney injury (K+ A). Two groups were formed of K+ A and non-K+ A patients after TKA. A univariate analysis was performed and the performance of the machine learning model was assessed by the area under the curve representing the sensitivity of the model as a function of 1 - specificity. RESULTS: Of the 774 patients included who had undergone TKA surgery, 46 patients (5.9%) had a postoperative kalaemia disorder requiring correction and 13 patients (1.7%) had acute kidney injury, of whom 5 patients (0.6%) received vascular filling. Eight variables were included in the machine learning predictive model, including body mass index, age, presence of diabetes, operative time, lowest mean arterial pressure, Charlson score, smoking and preoperative glomerular filtration rate. Overall performance was good with an area under the curve of 0.979 [CI95% 0.938-1.02], sensitivity was 90.3% [CI95% 86.2-94.4] and specificity 89.7% [CI95% 85.5-93.8]. The tool developed to assess the risk of impaired kalaemia and/or acute kidney injury after TKA is available on https://arthrorisk.com. CONCLUSION: The risk of kalaemia disturbance and postoperative acute kidney injury after total knee arthroplasty could be predicted by a model that identifies low-risk and high-risk patients based on eight pre- and intraoperative variables. This machine learning tool is available on a web platform accessible for everyone, easy to use and has a high predictive performance. The aim of the model was to better identify and anticipate the complications of dyskalaemia and postoperative acute kidney injury in high-risk patients. Further prospective multicentre series are needed to assess the value of a systematic postoperative biochemical work-up in the absence of risk predicted by the model. LEVEL OF EVIDENCE: IV; retrospective study of case series.

Total blood loss after hip hemiarthroplasty for femoral neck fracture: Anterior versus posterior approach.

INTRODUCTION: Femoral neck fractures constitute a public health problem due to significant associated morbidity and mortality amongst the ageing population. Perioperative blood loss can increase this morbidity. Blood loss, as well as the influence that the surgical approach exerts on it, remains poorly evaluated. We therefore conducted a retrospective comparative study in order to: (1) compare total blood loss depending on whether the patients were operated on using an anterior or posterior approach, (2) compare the transfusion rates, operating times and hospital stays between these two groups and, (3) analyze dislocation rates. HYPOTHESIS: Total blood loss is greater from an anterior approach following a hip hemiarthroplasty for femoral neck fracture, compared to the posterior approach. MATERIAL AND METHODS: This retrospective single-center comparative study included 137 patients operated on by hip hemiarthroplasty between December 2020 and June 2021, and seven patients were excluded. One hundred and thirty patients were analyzed: 69 (53.1%) had been operated on via the anterior Hueter approach (AA) and 61 (46.9%) via the posterior Moore approach (PA). The analysis of total blood loss was based on the OSTHEO formula to collect perioperative "hidden" blood loss. The risk of early dislocation (less than 6 months) was also analyzed. RESULTS: Total blood loss was similar between the two groups, AA: 1626±506mL versus PA: 1746±692mL (p=0.27). The transfusion rates were also similar between the two groups, AA: 23.2% versus PA: 31.1% (p=0.31) as well as the duration of hospitalization, AA: 8.5±3.2 versus PA: 8.2±3.3 days (p=0.54). The operating time was shorter in the PA group (Δ=10.3±14.1minutes [p<0.001]) with a greater risk of early dislocation when the patient was operated on by PA with AA: 9.8% versus PA: 1.4% (p=0.03). CONCLUSION: This study does not demonstrate any influence of the approach (anterior or posterior) on total blood loss. Transfusion rates and length of hospitalization were similar between the groups with a slightly shorter operating time but a greater risk of early dislocations after posterior hemiarthroplasty in a population at high anesthesia-related risk. LEVEL OF PROOF: III, comparative study of continuous series.

Minimally invasive sacroiliac joint fusion secondary to lumbosacral fusion: Clinical and functional results at 2years of follow-up.

INTRODUCTION: Degenerative sacroiliac (SI) joint syndrome is known to be more common after lumbosacral fusion. While this diagnosis is suspected based on various clinical criteria and diagnostic tests, it is confirmed with a diagnostic nerve block. If conservative treatment fails, SI joint fusion through a minimally invasive approach is a useful palliative approach for patients at a treatment crossroads. The aim of this study was to evaluate the clinical and functional results at 2years postoperative after minimally invasive SI joint fusion in patients with SI joint syndrome following lumbosacral fusion. MATERIALS AND METHODS: We carried out a single-center retrospective study of patients operated between June 2017 and October 2020. Included were patients who had a confirmed diagnosis of SI joint syndrome after lumbosacral fusion surgery, who underwent SI joint fusion and had at least 2years' follow-up. The primary outcome was the improvement in lumbar and radicular pain on a numerical rating scale (NRS). The secondary outcomes were the functional scores (Oswestry and SF-12) along with the level of patient satisfaction. Our study population consisted of 54 patients (41 women, 13 men) with a mean age of 59years (27-88). Thirty-one of these patients were operated on both sides (85 fusions in all). The patients had undergone a mean of 3 lumbar surgeries (1-7) before the SI fusion. RESULTS: The lumbar and radicular NRS were 8.4 (7-10) and 5.1 (2-10) preoperatively and 5.2 (0-8) and 3.0 (0-8) at 2years postoperatively, which was a reduction of 37% and 42% (p<0.001), respectively. The Oswestry score went from 69.4 (52-86) preoperatively to 45.6 (29-70) at 2years, which was a 33% improvement (p<0.001). Eighty-six percent of patients were satisfied or very satisfied with the surgery. DISCUSSION: After minimally invasive SI joint fusion, the patients in this study had clear clinical and functional improvements. Previous publications analyzing the results of SI joint fusion found even more improvement, but those patients were relatively heterogenous; in our study, only patients who had a history of lumbosacral fusion were included. CONCLUSION: Minimally invasive SI joint fusion helped patients who developed SI joint syndrome after lumbosacral fusion to improve clinically and functionally. LEVEL OF EVIDENCE: IV, retrospective study.

Is preoperative 3D planning reliable for predicting postoperative clinical differences in range of motion between two stem designs in reverse shoulder arthroplasty.

BACKGROUND: We aim to predict a clinical difference in the postoperative range of motion (RoM) between 2 reverse shoulder arthroplasty (RSA) stem designs (Inlay-155° and Onlay-145°) using preoperative planning software. We hypothesized that preoperative 3D planning could anticipate the differences in postoperative clinical RoM between 2 humeral stem designs and by keeping the same glenoid implant. METHODS: Thirty-seven patients (14 men and 23 women, 76 ± 7 years) underwent a BIO-RSA (bony increased offset-RSA) with the use of preoperative planning and an intraoperative 3-dimensional-printed patient-specific guide for glenoid component implantation between January 2014 and September 2019 with a minimum follow-up of 2 years. Two types of humeral implants were used: Inlay with a 155° inclination (Inlay-155°) and Onlay with a 145°inclination (Onlay-145°). Glenoid implants remained unchanged. The postoperative RSA angle (inclination of the area in which the glenoid component of the RSA is implanted) and the lateralization shoulder angle were measured to confirm the good positioning of the glenoid implant and the global lateralization on postoperative X-rays. A correlation between simulated and clinical RoM was studied. Simulated and last follow-up active forward flexion (AFE), abduction, and external rotation (ER) were compared between the 2 types of implants. RESULTS: No significant difference in RSA and lateralization shoulder angle was found between planned and postoperative radiological implants' position. Clinical RoM at the last follow-up was always significantly different from simulated preoperative RoM. A low-to-moderate but significant correlation existed for AFE, abduction, and ER (r = 0.45, r = 0.47, and r = 0.57, respectively; P < .01). AFE and abduction were systematically underestimated (126° ± 16° and 95° ± 13° simulated vs. 150° ± 24° and 114° ± 13° postoperatively; P < .001), whereas ER was systematically overestimated (50° ± 19° simulated vs. 36° ± 19° postoperatively; P < .001). Simulated abduction and ER highlighted a significant difference between Inlay-155° and Onlay-145° (12° ± 2°, P = .01, and 23° ± 3°, P < .001), and this was also retrieved clinically at the last follow-up (23° ± 2°, P = .02, and 22° ± 2°, P < .001). CONCLUSIONS: This study is the first to evaluate the clinical relevance of predicted RoM for RSA preoperative planning. Motion that involves the scapulothoracic joint (AFE and abduction) is underestimated, while ER is overestimated. However, preoperative planning provides clinically relevant RoM prediction with a significant correlation between both and brings reliable data when comparing 2 different types of humeral implants (Inlay-155° and Onlay-145°) for abduction and ER. Thus, RoM simulation is a valuable tool to optimize implant selection and choose RSA implants to reach the optimal RoM.

Acute compartment syndrome of the lower limbs: Fasciotomy or dermofasciotomy? A cadaver study of compartment pressures.

BACKGROUND: Acute compartment syndrome (ACS) of the lower limbs is a function-threatening event usually managed by extended dermofasciotomy. Closure of the skin may be delayed, creating a risk of complications when there is an underlying fracture. Early treatment at the pre-ACS stage might allow isolated fasciotomy with no skin incision. The primary objective of this study was to compare intracompartmental pressure (ICP) changes after fasciotomy and after dermofasciotomy. The secondary objectives were to evaluate potential associations linking the starting ICP to achievement of an ICP below the physiological cut-off of 10mm Hg and to determine whether the ICP changes after fasciotomy and dermofasciotomy varied across muscle compartments. HYPOTHESIS: Fasciotomy with no skin incision may not provide a sufficient ICP decrease, depending on the initial ICP value. MATERIAL AND METHODS: A previously validated model of cadaver ACS of the lower limbs was used. Saline was injected gradually to raise the ICP to>15mmHg (ICP15), >30mmHg (ICP30), and >50mmHg (ICP50). We studied 70 leg compartments (anterior, lateral, and superficial posterior) in 13 cadavers (mean age, 89.1±4.6years). ICP was monitored continuously. Percutaneous, minimally invasive fasciotomy consisting in one to three 1-cm incisions was performed in each compartment. ICP was measured before and after fasciotomy then after subsequent skin incision. The objective was to decrease the ICP below 10mmHg after fasciotomy or dermofasciotomy. RESULTS: Overall, mean ICP was 37.8±19.1mmHg after the injection of 184.0±133.01mL of saline. In the ICP15 group, the mean ICP of 16.1mmHg fell to 1.4mmHg after fasciotomy (ΔF=14.7) and 0.3mmHg after dermofasciotomy (ΔDF=1.1). Corresponding values in the ICP30 group were 33.9mmHg, 4.7mmHg (ΔF=29.2), and 1.2mmHg (ΔDF=3.5); and in the ICP50 group, 63.7mmHg, 17.0mmHg (ΔF=46.7), and 1.2mmHg (ΔDF=15.8). Thus, in the group with initial pressures >50mmHg, the ICP decrease was greater after both procedures, but fasciotomy alone nonetheless failed to achieve physiological values (<10mmHg). The pressure changes were not significantly associated with the compartment involved (anterior, lateral, or superficial posterior) (p<0.05). CONCLUSION: Under the conditions of this study, higher baseline ICPs were associated with larger ICP drops after fasciotomy and dermofasciotomy. Nevertheless, when the baseline ICP exceeded 50mmHg, fasciotomy alone failed to decrease the ICP below 10mmHg. Adding a skin incision achieved this goal. LEVEL OF EVIDENCE: IV, experimental study.

Early morbidity and mortality after one-stage bilateral shoulder arthroplasty.

PURPOSE: One-stage bilateral shoulder arthroplasty has the advantage of requiring a single hospital stay and a single anaesthesia. The topic has been little reported, unlike one stage bilateral hip and knee arthroplasty, which have demonstrated their interest. The aim of the present study was to determine peri- and early post-operative morbidity and mortality after this procedure. The study hypothesis was that peri- and early post-operative morbidity and mortality in one stage bilateral shoulder arthroplasty is low in selected patients and that satisfaction is high. METHODS: A single-centre retrospective study assessed peri- and early post-operative morbidity and mortality in one stage bilateral shoulder arthroplasty. Twenty-one patients, aged < 80 years, with ASA score ≤ 3, were consecutively operated on between 1999 and 2020. Indications comprised primary osteoarthritis, aseptic osteonecrosis, inflammatory arthritis, massive rotator cuff tear, and dislocation fracture, involving both shoulders. RESULTS: There were no early deaths. The complication rate was 10% (4/21 cases). No prosthesis dislocation or sepsis was reported. Mean blood loss was 145 ± 40 cc, mean surgery time 164 ± 63 min, and mean hospital stay five ± four days. Only one patient required postoperative transfusion. Functional results at six months showed significantly improved range of motion and good patient satisfaction. CONCLUSIONS: One-stage bilateral shoulder arthroplasty was feasible in selected patients. Mortality was zero, and morbidity was low. Surgery time was reasonable and required no repositioning. Postoperative home help is indispensable for patient satisfaction during rehabilitation.

An Evaluation of the Reliability of Manual Landmark Identification on 3D Segmented Wrists.

BACKGROUND: Three-dimensional (3D) preoperative planning is increasingly used in orthopaedic surgery. Two-dimensional (2D) characterization of distal radial deformities remains inaccurate, and 3D planning requires a reliable reference frame at the wrist. We aim to evaluate the reliability of the determination of anatomical points placed manually on 3D models of the radius to determine which of those points allow reliable morphometric measurements. METHODS: Twenty-three radial scans were reconstructed in 3D. Five operators specialized in the upper limb manually positioned 8 anatomical points on each model. One of the operators repeated the operation 6 times. The anatomical points were based on previously published 3D models used for radial inclination and dorsopalmar tilt measurements. The repeatability and reproducibility of the measurements derived using this manual landmarking were calculated using different measurement methods based on the identified points. An error of ≤2° was considered clinically acceptable. RESULTS: This study of intraobserver and interobserver variability of the anatomic points allowed us to determine the least variable and most accurately defined points. The middle of the ulnar border of the radius, the radial styloid, and the midpoint of the ulnar incisura of the radius were the least variable. The palmar and dorsal ends of the ridge delineating the scaphoid and lunate facets were the most variable. Only 1 of the radial inclination measurement methods was clinically acceptable; the others had a repeatability and reproducibility limit of >2°, making those measurements clinically unacceptable. CONCLUSIONS: The use of isolated points seems insufficient for the development of a wrist reference frame, especially for the purpose of measuring dorsopalmar tilt. If one concurs that an error of 2° is unacceptable for all distal radial measurements, then clinicians should avoid using 3D landmarked points, due to their unreliability, except for radial inclination measured using the radial styloid and the midpoint of the ulnar edge of the radius. A characterization of the wrist using 3D shapes that fit the articular surface of the radius should be considered. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Restoration of preoperative tibial alignment improves functional results after medial unicompartmental knee arthroplasty.

PURPOSE: The alignment obtained after unicompartmental knee arthroplasty (UKA) influences the risk of failure. Kinematic alignment after UKA based on Cartier angle restauration is likely to improve clinical outcomes compared with mechanical alignment. The purpose of this study is to analyze the influence of implant alignment and native knee restoration after UKA using the conventional techniques on clinical outcomes. METHODS: This retrospective study included 144 medial UKA patients from 2015 to 2020. Radiographic measurements were performed pre- and postoperatively. Outliers were defined as follows: Δ Cartier > 3° (difference between the preoperative and postoperative Cartier angle); Δ MPTA (Medial Proximal Tibial angle) and postoperative TCA (Tibial Coronal component Angle) > 3° (difference between the positioning of the tibial implant and the preoperative proximal tibial deformity). The Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Society (IKS) Function and Knee score, the Forgotten Joint Score (FJS), and the Subjective Knee Value (SKV) were evaluated. A Student t test or a non-parametric Wilcoxon test was used for non-normal data to compare pre- and postoperative values for functional scores and angular measurements. The correlation of postoperative angles with functional outcomes was assessed by the Spearman's rank correlation coefficient. RESULTS: During the inclusion period, 214 patients underwent medial UKA, 71 patients were excluded, and 19 were lost to follow-up leaving 124 patients with 144 knees (20 bilateral UKA) included for analysis with a mean follow-up of 54.7 months ± 22.1 (24-95). The Δ Cartier was significantly correlated with IKS function (R2 = 0.06, p < 0.001) and FJS (R2 = 0.05, p < 0.01) scores. The Δ preoperative MPTA-TCA was significantly correlated (p < 0.001) with KOOS (R2 = 0.38), IKS Knee (R2 = 0.17), IKS function (R2 = 0.34), SKV (R2 = 0.08), and FJS (R2 = 0.37) scores. In subgroup analysis, non-outliers (< 3°) for Δ preoperative MPTA-TCA had better KOOS score (Δ = 23.5, p < 0.001) and IKS Function (Δ = 17.7, p < 0.001) compared to outliers (> 3°) patients. CONCLUSION: Functional results after medial UKA can be influenced by implant alignment in the coronal plane with slight clinical improvement when positioning the tibial implant close to the preoperative tibial deformity, rather than by restoring the Cartier angle. This series suggests the interest of a more personalized alignment strategy, but these results will have to be confirmed by other controlled studies. LEVEL OF EVIDENCE: IV, retrospective case series.

Normo-or slightly overcorrection show better results after medial closing wedge high tibial osteotomy.

PURPOSE: The objectives of this study were to evaluate functional results, revision-free survival, and the influence of postoperative alignment on outcomes after MCWHTO. METHODS: This retrospective study included 27 MCWHTO operated on from 2009 to 2021. Radiographic measurements were performed pre- and postoperatively. The HKA (Hip-Knee-Ankle angle), MPTA (Medial Proximal Tibial angle), LDFA (Lateral Distal Femoral Angle), JLO (Joint Line Obliquity), and JLCA (Joint Line Convergence Angle) were evaluated. The Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Society (IKS) Function and Knee Score, and the Subjective Knee Value (SKV) as well as revision-free survival were evaluated. Postoperative alignment and its influence on clinical outcomes were also analysed. RESULTS: The mean follow-up was 61.9 months ± 31.4 (13-124). The HKA, MPTA, and JLCA angles were decreased post-operatively (respectively, Δ = 5.9° ± 2.6, p < 0.001; Δ = 6.1° ± 3.2, p < 0.001 and Δ = 2.5° ± 1.9, p < 0.001). LDFA and JLO were unchanged, post-operatively (respectively, Δ = 0.1° ± 2.2, p = 0.93 and Δ = 1.2° ± 3.3, p = 0.23). Postoperative HKA correlated with knee IKS (R = - 0.15, p = 0.04) and function IKS (R = - 0.44, p = 0.03). Postoperative LDFA correlated with knee IKS(R = 0.8, p < 0.01). Patients with postoperative HKA ≤ 180° had better KOOS (Δ = 12.3, p = 0.04) and IKS function (Δ = 28.1, p < 0.01) than those with HKA > 180°. CONCLUSION: Functional results and revision-free survival after MCWHTO are satisfactory when the deformity is located in the proximal tibia. The joint line obliquity is not significantly altered with small tibial correction and, obtaining an overall neutral or slightly varus alignment under the conditions of this study allowed an improvement in the postoperative clinical scores. The literature is still inconclusive on the ideal alignment for valgus deformities and larger series are needed to draw definitive conclusions. LEVEL OF EVIDENCE: IV, case series.

The impact of confinement on orthopaedic and trauma surgical activity.

INTRODUCTION: On the 16th of March 2020, in the face of a health emergency declared in France, the government imposed containment measures whose impact on orthopaedic and trauma surgery remains to be demonstrated. The hypothesis of this study was that confinement reduced orthopaedic and trauma surgical activity. The main objective was to assess orthopaedic and trauma surgical activity during confinement and to compare it to the activity outside confinement. MATERIALS AND METHODS: This was a retrospective, monocentric, observational and comparative study of a continuous cohort of patients included during the confinement period of March 16th to May 11th, 2020. This cohort was retrospectively compared to a group of patients over the same non-confinement period in the previous year, from March 16th to May 11th, 2019. The primary outcome measured was the incidence rate of surgical activity in 2020 versus 2019 over an identical period. The secondary outcome was the analysis of the trauma identified. RESULTS: The number of patients operated on was significantly reduced during confinement: 194 patients were included in 2020, i.e. an incidence of 57 per 100,000 inhabitants against 772 patients included in 2019, i.e. an incidence of 227 per 100,000 inhabitants; p<0.001. Planned orthopaedic surgery decreased from an incidence rate of 147 in 2019 to 5 in 2020 per 100,000 inhabitants (p<0.001). Trauma surgery decreased from an incidence rate of 80 in 2019 to 50 in 2020 per 100,000 inhabitants (p: NS). We found a significant increase in patients over 65years of age during confinement, 70% compared to 61% in 2019; p=0.04. The rate of femoral neck fractures was significantly increased during confinement, 48.5% compared to 39.3% in 2019; p=0.03. Degenerative surgery was significantly reduced during confinement (p<0.001). DISCUSSION: This study shows that the surgical activity of orthopaedics and trauma was significantly reduced by confinement, with a difference in incidence of 170 per 100,000 inhabitants, thus confirming the hypothesis of the authors. This decrease is due to both the cessation of planned orthopaedics and the 40% decrease in the number of trauma patients. During confinement, the percentage of patients over the age of 65 with a fracture increased significantly. CONCLUSION: Confinement had a significant impact on orthopaedic and trauma surgical activity. LEVEL OF EVIDENCE: III; comparative and retrospective.

Validation of the shoulder range of motion software for measurement of shoulder ranges of motion in consultation: coupling a red/green/blue-depth video camera to artificial intelligence.

PURPOSE: Clinical evaluation of the shoulder range of motion (RoM) may vary significantly depending on the surgeon. We aim to validate an automatic shoulder RoM measurement system associating image acquisition by an RGB-D (red/green/blue-depth) video camera to an artificial intelligence (AI) algorithm. METHODS: Thirty healthy volunteers were included. A 3D RGB-D sensor that simultaneously generated a colour image and a depth map was used. Then, an open-access convolutional neural network algorithm that was programmed for shoulder recognition provided a 3D motion measure. Each volunteer adopted a randomized position successively. For each position, two observers made a visual (EyeREF) and goniometric measurement (GonioREF), blind to the automated software which was implemented by an orthopaedic surgeon. We evaluated the inter-tester intra-class correlation (ICC) between observers and the concordance correlation coefficient (CCC) between the three methods. RESULTS: For manual evaluations EyeREF and GonioREF, ICC remained constantly excellent for the widest motions in the vertical plane (i.e., abduction and flexion). It was very good for ER1 and IR2 and fairly good for adduction, extension, and ER2. Differences between the measurements' means of EyeREF and shoulder RoM was significant for all motions. Compared to GonioREF, shoulder RoM provided similar results for abduction, adduction, and flexion and EyeREF provided similar results for adduction, ER1, and ER2. The three methods showed an overall good to excellent CCC. The mean bias between the three methods remained under 10° and clinically acceptable. CONCLUSION: RGB-D/AI combination is reliable in measuring shoulder RoM in consultation, compared to classic goniometry and visual observation.

Modern and synchronized clinical anatomy teaching based on the BDIE method (board-digital dissection-imaging-evaluation).

PURPOSE: Anatomy has historically been taught via traditional medical school lectures and dissection. In many countries, practical or legal issues limit access to cadaveric dissection. New technologies are favored by students and could improve learning, complementing traditional teaching. METHODS: All students in second-year medicine at a single medical school were submitted to a novel anatomical course with digital tool exposure. We explored a new combined teaching method: a physical blackboard lesson synchronized with digital dissection, imaging and direct evaluation (BDIE). Synchronized dissection is broadcast live in the classroom and in partner medical schools. Following the course, students completed a short survey about their perception of this new anatomic clinical course. RESULTS: The survey included 183 students whom 178 completed the questionnaire, i.e., a 97% response rate. Ninety-nine percent of students thought this synchronized method useful to improve their understanding of anatomy and 90% stated it helped them retain this learning. CONCLUSION: This BDIE method, in conjunction with teaching guidelines and dissection, is highly appreciated by students who consider it helps them to acquire lasting knowledge.

CT-Guided Percutaneous Vertebroplasty for Vertebral Non-union Following Posterior Fixation: A Preliminary Retrospective Study.

PURPOSE: Traumatic thoracolumbar vertebral fractures are frequently treated with posterior fixation (PF) and vertebral augmentation. Sometimes, it is deemed too risky to offer vertebral augmentation under fluoroscopic guidance alone. Adjuvant CT/fluoroscopy-guided percutaneous vertebroplasty (PVP) could be offered in certain scenarios. The aim was to evaluate feasibility, safety and effectiveness of PVP in patients presenting with vertebral non-union (VNU) following PF performed without concomitant vertebral augmentation. MATERIALS AND METHODS: All patients treated in our institution with PVP between July 2015 and July 2020 were retrospectively reviewed. Patients treated with CT/fluoroscopy-guided PVP under local anesthesia for symptomatic VNU following PF were selected. Three criteria were established to assess cement distribution, considering vertebral filling of: (1) fracture cleft, (2) anterior two-thirds of the vertebral body, (3) from superior to inferior endplates. Numeric pain rating scale (NPRS) assessing grade of discomfort (0 = no pain; 10 = worst pain) and complications were evaluated before and 1 month after PVP. RESULTS: Ten patients were identified (mean age 53 ± 12y). Mean time between PF and PVP was 9.6 [2-35] months. Two patients required further cement injection with a second PVP. Eight patients had satisfactory vertebral filling according to the three criteria. Mean NPRS reduction was 2.7(-42%, p < 0.05). No significant complications occurred. CONCLUSIONS: Combined CT/fluoroscopy guidance seems a useful tool to perform PVP in VNU following PF, even in presence of orthopedic metalwork. Interventional radiologists may help in these scenarios, performing an adjuvant PVP under local anesthesia. In this small series, the procedure seems safe and effective and could be taken in consideration as alternative to revision surgery.

Flow-Through Arterialized Posterior Interosseous Nerve Grafts for Digital Neurovascular Bundle Defects: Anatomical Study.

BACKGROUND: Digital neurovascular bundle defects are often encountered during crush or avulsion injuries and require complex reconstruction. Use of an arterialized nerve graft (neurovascular graft) serving both as an interpositional arterial conduit and as a nerve graft could be a reconstructive option in these cases. In this anatomical study, the authors aimed to describe a neurovascular graft of the posterior interosseous nerve and a branch of the anterior interosseous artery for neurovascular bundle reconstruction of the fingers. METHODS: Eighteen forearms were injected with red latex in order to collect the anatomical characteristics of the posterior interosseous nerve and the artery running near it. RESULTS: In all cases, the posterior interosseous nerve was followed by a branch of the anterior interosseous artery: the distal dorsal branch of the anterior interosseous nerve. The origin of this artery was proximal to the radiocarpal joint, at an average of 56.5 ± 11.1 mm. The proximal and distal diameters of the branch of the anterior interosseous artery were 1.6 ± 0.2 and 1.1 ± 0.2 mm, respectively. The proximal and distal diameters of the posterior interosseous nerve were 1.2 ± 0.3 mm and 1.1 ± 0.3 mm, respectively. CONCLUSIONS: These results show that a potential free neurovascular graft using the posterior interosseous nerve as nerve graft and the anterior interosseous artery as an arterial bypass to reconstruct both the nerve and arterial tree of the finger could be a useful approach. The authors speculate that this graft could be used to reconstruct the neurovascular bundle of amputated or devascularized digits.

Percutaneous Cement Discoplasty for Degenerative Low Back Pain with Vacuum Phenomenon: A Multicentric Study with a Minimum of 2 Years of Follow-Up.

BACKGROUND: To report clinical results after percutaneous cement discoplasty (PCD) in a multicentric case series with a minimum of 2 years of follow-up. METHODS: Between December 2014 and January 2019, 180 patients with low back pain and advanced degeneration were treated with percutaneous discoplasty in 2 centers. The inclusion criteria were as follows: patients 65 years or older, with mechanical low back pain with or without spinal stenosis, who did not respond to conservative management. Patients were divided into 3 groups: group 1: patients without previous spine surgeries who underwent PCD, group 2: patients with previous spine surgeries who underwent PCD, and group 3: patients with/without previous surgery who underwent PCD plus decompression surgery. Clinical and radiological analyses were performed as well as complication and readmission rates. RESULTS: A total of 156 patients (74% female; mean age, 75.8 ± 5.7 years; mean body mass index, 29.9 ± 5.2) were included in our study. Overall preoperative visual analog score (VAS) and Oswestry Disability Index (ODI) were 7.8 ± 0.9 and 68.1 ± 9.6, respectively. At 2 years of follow-up, mean VAS improvement was 3.56 (95% confidence interval: 3.92-3.20; P < 0.0001) and mean ODI improvement was 17.18 (95% confidence interval: 19.52-14.85; P < 0.0001), showing a significant and sustained improvement in both scores. In addition, 84% of patients reached both VAS and ODI minimum important clinical difference at the final follow-up. Finally, 5.7% of patients suffered major complications 30 days postoperatively. CONCLUSIONS: PCD showed significant improvement of VAS and ODI scores at 2 years of follow-up with relatively low rate of complications.

Pyrocarbon unipolar radial head prosthesis: clinical and radiologic outcomes at long-term follow-up.

BACKGROUND: Several studies have already reported good short-term results with a pyrocarbon unipolar radial head prosthesis (Pyc-uRHP). The aim was to evaluate the evolution from mid- to long-term clinical and radiographic outcomes of a Pyc-uRHP. METHODS: This was a retrospective, single-center study. We followed up all the patients who underwent Pyc-uRHP surgery in our original study at 2 years of follow-up (52 patients), reaching a minimum of 7 years of clinical and radiologic follow-up. This study included 26 patients who underwent a clinical examination assessing mobility, the Mayo Elbow Performance Score, and the visual analog scale score and radiologic evaluation with anteroposterior and profile radiographs at a mean follow-up of 110 months (range, 78-162 months). The radiologic study analyzed signs of proximal osteolysis, stem loosening, capitellar wear, and humeroulnar osteoarthritis. RESULTS: No patients required revision. Eight patients required reoperation: coronoid screw removal in 1 and arthrolysis for stiffness in 7. The mean time to reoperation was 11 months. The mean Mayo Elbow Performance Score at last follow-up was 96 ± 9 (of 100), with a pain score of 42 ± 7 (of 45), mobility score of 19 ± 2 (of 20), stability score of 10 (of 10), and function score of 25 (of 25). Comparison with clinical data from the mid-term delay did not reveal any significant difference. All patients presented with proximal osteolysis around the neck but without progression. No stem loosening was noted. The rates of humeroulnar osteoarthritis (12% at mid-term vs. 80% at last follow-up, P < .0001) and capitellar lesions (34% at mid-term vs. 80% at last follow-up, P = .001) increased significantly. CONCLUSION: We have shown that a Pyc-uRHP at 9 years' follow-up provided stable and satisfactory clinical results. Osteolysis of the radial neck was always present but it did not evolve, and no stem loosening was noted. Finally, we have shown a clear worsening of radiologic humeroulnar osteoarthritis and capitellar lesions that remained asymptomatic.

Patient-Specific Three-Dimensional-printed Instrumentation for Radius Lengthening Osteotomy by a Volar Approach in Epiphysiodesis Sequelae: A Case Report.

INTRODUCTION: Patient-specific guides are used in the correction of malunion sequelae in adult distal radius fractures. They allow a tridimensional correction of radial glenoid orientation. However, lengthening is small in those indications. Distal radius epiphysiodesis correction is much rarer and patient-specific guide after three-dimensional (3D) planning has never been reported for this indication in the literature. CASE REPORT: We report the case of a 16-year-old teenager with a chronic painful wrist and an ulnar positive variance after a post-traumatic epiphysiodesis sequela of the radius. The radius was 11mm shorter than the ulna. An anatomic reconstruction was decided with a lengthening of the radius. Pre-operative planning and patient-specific guide allowed to control an important radial lengthening, to limit the morbidity of the iliac crest bone graft harvesting, to shape the graft precisely, and to maintain a correct radial glenoid orientation despite the important soft tissue tension. Clinical and radiological results at 6 months showed a complete disappearance of pain, optimal objective and subjective functional scores, and an improvement in the distal ulnar variance (7mm). The teenager went back to sport without limitation or pain. CONCLUSION: 3Dplanning and intraoperative patient-specific guides in radial epiphysiodesis sequelae allow achieving 3D accurate measures of the graft and of the deformation, guiding the position and the orientation of the distal metaphysis cut of the radius, and limiting the morbidity of the iliac graft harvesting. In that case, it allowed restoring the full function of the wrist without remaining pain.

Sacroiliac joint syndrome after lumbosacral fusion.

INTRODUCTION: One-third of low back pain cases are due to the sacroiliac (SI) joint. The incidence increases after lumbosacral fusion. A positive Fortin Finger Test points to the SI joint being the origin of the pain; however, clinical examination and imaging are not specific and minimally contributory. The gold standard is a test injection of local anesthetic. More than 70% reduction in pain after this injection confirms the SI joint is the cause of the pain. The aim of this study was to evaluate the decrease in pain on a Numerical Rating Scale (NRS) after intra-articular injection into the SI joint. We hypothesised that intra-articular SI injection will significantly reduce SI pain after lumbosacral fusion. METHODS: All patients with pain (NRS>7/10) suspected of being caused by SI joint syndrome 1 year after lumbosacral fusion with positive Fortin test were included. Patients with lumbar or hip pathologies or inflammatory disease of the SI joint were excluded. Each patient underwent a 2D-guided injection of local anesthetic into the SI joint. If this failed, a second 2D-guided injection was done; if this also failed, a third 3D-guided injection was done. Reduction of pain on the NRS by>70% in the first 2 days after the injection confirmed the diagnosis. Whether the injection was intra-articular or not, it was recorded. Ninety-four patients with a mean age of 57 years were included, of which 70% were women. RESULTS: Of the 94 patients, 85 had less pain (90%) after one of the three injections. The mean NRS was 8.6/10 (7-10) before the injection and 1.7/10 after the injection (0-3) (p=0.0001). Of the 146 2D-guided injections, 41% were effective and 61% were intra-articular. Of the 34 3D-guided injections, 73% were effective and 100% were intra-articular. DISCUSSION: This study found a significant decrease in SI joint-related pain after intra-articular injection into the SI joint in patients who still had pain after lumbosacral fusion. If this injection is non-contributive when CT-guided under local anesthesia, it can be repeated under general anesthesia with 3D O-arm guidance. This diagnostic strategy allowed us to confirm that pain originates in the SI joint after lumbosacral fusion in 9 of 10 patients. CONCLUSION: If the first two CT-guided SI joint injections fail, 3D surgical navigation is an alternative means of doing the injection that helps to significantly reduce SI joint-related pain after lumbosacral fusion. LEVEL OF EVIDENCE: IV, retrospective study.