Accuracy and clinical role of digital templating for total knee arthroplasty performed on haemophilic knees.

INTRODUCTION: In total knee arthroplasty (TKA), choosing the correct implant size is important. There is lack of data on accuracy of templating on haemophilic knees. Our aim was to test the accuracy of 2D digital templating for TKA on haemophilic arthropathy (HA) of knee. MATERIALS AND METHODS: TKAs performed on HA between January 2011 and January 2022 were screened. Osteoarthritis (OA) group was created as control group by a one-to-one matching regarding type of implant used. Intra- and interobserver correlations were measured in HA, then correlation between templated and implanted sizes was investigated in four assessments (femur AP, femur lateral, tibia AP, tibia lateral), then compared with OA group. Fifty-eight knees in each group included. RESULTS: Regarding intraobserver correlation in HA, there was excellent correlation for femur AP [.93 (.73-.98)], femur lateral [.98 (.91-.99)], and tibia AP (1.0) templating. Regarding interobserver correlation in HA, excellent correlation was observed for femur lateral [.93 (.74-.98)] and tibia AP templating [.90 (.65-.97)]. Regarding correlation of templated and applied sizes in HA; tibia AP, tibia lateral and femur lateral templating showed good correlation [.81 (.70-.89), .86 (.77-.91), .79 (.67-.87) while femur AP templating showed moderate correlation [.67 (.50-.79)]. Comparing HA and OA, there was no difference in correlation levels regarding femur AP, femur lateral, tibia AP and tibia lateral templating (p = .056, p = .781, p = .761, p = .083, respectively). CONCLUSION: Although 2D digital templating shows comparable correlation in HA and OA, clinical applicability of templating on HA appears to be limited in its current state.

Long-term results and surgical strategy development for degenerative disease treatment in athletes: a retrospective single-center study.

PURPOSE: To analyze of the results of spine surgical treatment of athletes with lumbar degenerative disease and development of a surgical strategy based on the preoperative symptoms and radiological changes in the lumbar spine. METHODS: For 114 athletes with lumbar degenerative disease were included in the present study. Four independent groups were studied: (1) microsurgical/endoscopic discectomy (n = 35); (2) PRP therapy in facet joints (n = 41); (3) total disc replacement (n = 11); (4) lumbar interbody fusion (n = 27). We evaluated postoperative clinical outcomes and preoperative radiological results. The average postoperative follow-up was 5 (3;6), 3.5 (3;5), 3 (2;4) and 4 (3;5) years, respectively. The analysis included an assessment of clinical outcomes (initial clinical symptoms, chronic pain syndrome level according to the VAS, quality of life according to the SF-36 questionnaire, degree of tolerance to physical activity according to the subjective Borg Rating of Perceived Exertion Scale) and radiological data (Dynamic Slip, Dynamic Segmental Angle, degenerative changes in the facet joint according to the Fujiwara classification and disc according to the Pfirrmann classification; changes in the diffusion coefficient using diffusion-weighted MRI). RESULTS: The median and 25-75% quartiles timing of return to sports were 12.6 (10.2;14.1), 2.8 (2.4;3.7), 9 (6;12), and 14 (9;17) weeks, respectively. We examined the type of surgical treatment utilized, as well as the preoperative clinical symptoms, severity of degenerative changes in the intervertebral disc and facet joint, the timing of return to sports, the level of pain syndrome, the quality of life according to SF-36, and the degree of tolerance to physical activity. We then developed a surgical strategy based on individual preoperative neurological function and lumbar morphological changes. CONCLUSIONS: In this retrospective study, we report clinical results of four treatment options of lumbar spine degenerative disease in athletes. The use of developed patient selection criteria for the analyzed surgical techniques is aimed at minimizing return-to-play times.

Assessment of preoperative planning and intraoperative accuracy of the AIKNEE system for total knee arthroplasty.

BACKGROUND: The aim of this retrospective study was to evaluate the effectiveness and accuracy of the AIKNEE system in preoperative planning and intraoperative alignment for total knee arthroplasty (TKA). METHODS: A total of 64 patients were planned preoperatively by the AIKNEE system, including the measurement of mechanical femorotibial angle (mFTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) using three-dimensional reconstructed images. Intraoperatively, the actual prosthesis size and alignment were compared to the planned parameters. Postoperative outcomes, including pain levels, range of motion (ROM), and Knee Scoring System (KSS) scores, were assessed after surgery. Statistical analyses were performed to evaluate the correlation between alignment deviations and postoperative function. RESULTS: The AIKNEE system accurately predicted the prosthesis size in thirty-one of femoral cases (48%) and forty-seven of tibial cases (73%). Deviations of mFTA, LDFA, and MPTA from the target value were within 3° in 88%, 92%, and 95% of cases, respectively. A significant improvement was observed in postoperative pain, ROM, and KSS scores (p < 0.001). Correlation analysis revealed that greater deviations in mFTA and LDFA were associated with increased pain (p = 0.004, 0.047) and lower KSS scores (p = 0.027). CONCLUSION: The AIKNEE system demonstrated promising results in predicting prosthesis size and achieved alignment within the desired range in a majority of cases. Postoperative outcomes, including pain levels and functional improvement, were favorable.

Assessment of language lateralization in epilepsy patients using the super-selective Wada test.

BACKGROUND: The classical Wada test (cWada), performed by injecting a short-acting anesthetic through the intracarotid route, helps determine language dominance. In the cWada, adverse effects are observed in 10-30% of trials, hindering accurate assessments. In this study, we assessed the effectiveness of the super-selective Wada test (ssWada), a more selective approach for anesthetic infusion into the middle cerebral artery (MCA). METHODS: We retrospectively examined the data of 17 patients with epilepsy who underwent ssWada via anesthetic injection into one M1 segment of the MCA and at least one contralateral trial. RESULTS: The ssWada identified 12 patients with left language dominance, 3 with right language dominance, and 2 with bilateral language distribution. Nine trials on the language dominant side resulted in global aphasia for patients with left- or right language dominance. Of the 13 trials conducted on the non-dominant language side, 12 revealed intact language function and one resulted in confusion. Among these, the outcomes of global aphasia or no language impairment were confirmed in the contralateral trials. Among the 22 trials of unilateral M1 injections in patients with unilateral language dominance, 21 (95.5%) showed either global aphasia or no language impairment, indicating language dominance. CONCLUSIONS: The ssWada yields clear results, with a high rate of over 90% in determining the language dominant hemisphere with few side effects.

Preoperative joint line obliquity, a newly identified factor for overcorrection, can be incorporated into a novel preoperative planning method to optimise alignment in high tibial osteotomy.

PURPOSE: The aim of this study was to analyse the factors associated with additional postoperative alignment changes after accurate bony correction by selecting only patients with well-performed bony correction as planned and develop a method of incorporating significant factors into preoperative planning. METHODS: Among 104 consecutive patients who underwent medial open wedge high tibial osteotomy (MOWHTO) between October 2019 and July 2022, 61 with well-performed bony corrections were retrospectively reviewed. The major criterion for well-performed bony correction was a difference of <1° between the simulated medial proximal tibial angle (MPTA) and the actual postoperative MPTA as measured in three dimensions. Radiographic parameters, such as the joint line convergence angle (JLCA) and joint line obliquity (JLO), were measured preoperatively and postoperatively, utilising standing and supine whole lower extremity anteroposterior, valgus and varus stress radiographs. Multiple linear regression analysis identified the factors affecting alignment changes, and a prediction model was developed. A method for applying this prediction model to preoperative planning was proposed. RESULTS: Preoperative JLCA on standing (preJLCAstd ), preoperative JLCA on 0° valgus stress radiograph (vgJLCA0 ), and preoperative JLO (preJLO) were significantly correlated with JLCA change (∆JLCA) (p < 0.001, p < 0.001, p = 0.006). The prediction model was estimated as ∆JLCA = 0.493 × (vgJLCA0 ) - 0.727 × (preJLCAstd ) + 0.189 × (preJLO) - 1.587 in. (R = 0.815, modified R2 = 0.646, p < 0.001). The proposed method resulted in a reduced overcorrection rate (p = 0.003) and an improved proportion of acceptable alignments (p = 0.013). CONCLUSION: PreJLCAstd , vgJLCA0  and preJLO can be used to estimate ∆JLCA. PreJLO was recently identified as a significant factor associated with additional alignment changes. Utilising the proposed preoperative planning and a prediction model with these factors shows promise in calibrating postoperative alignment after MOWHTO. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Functional preoperative assessment of coronal knee laxity better predicts postoperative patient outcomes than intraoperative surgeon-defined laxity in total knee arthroplasty.

PURPOSE: Intraoperative laxity assessments in total knee arthroplasty (TKA) are subjective, with few studies comparing against standardised preoperative and postoperative assessments. This study compares coronal knee laxity in TKA patients awake and anaesthetised, preprosthesis and postprosthesis implantation, evaluating relationships to patient-reported outcome measures. METHODS: A retrospective analysis of 49 TKA joints included preoperative and postoperative computed tomography scans, stress radiographs and knee injury and osteoarthritis outcome score (KOOS) questionnaire results preoperatively and 12 months postoperatively. The imaging was used to assess functional laxity (FL) in awake patients, whereas computer navigation measured intraoperative surgical laxity (SL) preimplantation and postimplantation, with patients anaesthetised. Varus and valgus stress states and their difference, joint laxity, were measured. RESULTS: SL was greater than FL in both preimplantation [8.1° (interquartile range, IQR 2.0°) and 3.8° (IQR 2.9°), respectively] and postimplantation [3.5° (IQR 2.3°) and 2.5° (IQR 2.7°), respectively]. Preimplantation, SL was more likely than FL to categorise knees as correctable to ±3° of the mechanical axis. Preoperative FL correlated with KOOS Symptoms (r = 0.33, p = .02) and quality of life (QOL) (r = 0.38, p = .01), whereas reducing medial laxity with TKA enhanced postoperative QOL outcomes (p = .02). CONCLUSIONS: Functional coronal knee laxity assessment of awake patients is generally lower than intraoperative surgical assessments of anaesthetised patients. Preoperative SL may result in overcorrection of coronal TKA alignment, whereas preoperative FL better predicts postoperative patient outcomes and reflects the patients' native and tolerable knee laxity. Preoperative FL assessment can be used to guide surgical planning. LEVEL OF EVIDENCE: Level II.

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.

Comparison of 3D computer-assisted planning with and without patient-specific instrumentation for severe bone defects in reverse total shoulder arthroplasty.

BACKGROUND: Preoperative planning is an integral aspect of managing complex deformity in reverse shoulder arthroplasty (RSA). The purpose of this study was to compare the success of patient-specific instrumentation (PSI) and 3D computer-assisted planning with standard instrumentation (non-PSI) in achieving planned corrections of the glenoid among patients undergoing RSA with severe bony deformity requiring glenoid bone grafts. METHODS: A retrospective case-control study was performed, including all patients that underwent RSA with combined bone grafting procedures (BIO-RSA or structural bone grafting) for severe glenoid deformity by a single study between June 2016 and July 2023. Patients were required to have preoperative and postoperative CT scans as well as preoperative 3D planning performed for inclusion. Patients were divided into two groups based on the use of 3D computer-assisted planning with or without PSI (PSI vs. non-PSI). The corrected inclination and version were measured by two separate reviewers on preoperative and postoperative 2D CT scans and compared to their corresponding preoperative planning goals utilizing bivariate analyses. RESULTS: We identified 45 patients that met our inclusion criteria (22 PSI and 23 non-PSI). Preoperative inclination (mean ± SD) (PSI 10.12° ± 15.86°, non-PSI 9.43° ± 10.64°; P = .864) and version (PSI -18.78° ± 18.3°, non-PSI -17.82° ± 11.49°; P = .835) measurements were similar between groups. No significant differences in the mean deviation (error) between the postoperative and planned inclination (PSI 5.49° ± 3.72; non-PSI 6.91° ± 5.05; P = .437) and version (PSI 8.37° ± 5.7; non-PSI 5.37° ± 4.43; P = .054) were found between groups. No difference in the rate of outliers (>10° error) was noted in inclination (P = .135) or version (P = .445) between groups. Greater planned version correction was correlated with greater error when PSI was utilized (PSI r = 0.519, P = .013; non-PSI r = 0.362, P = .089). CONCLUSION: Both PSI and 3D computer-assisted planning without PSI (non-PSI) appear to be useful techniques to achieve version and inclination correction among patients undergoing RSA with severe glenoid deformity required glenoid bone grafting with no clear superiority of one method over the other. Surgeons should be aware that when utilizing PSI, slightly greater error in achieving version goals may occur as version correction is increased.

3-dimensionally printed patient-specific glenoid drill guides vs. standard nonspecific instrumentation: a randomized controlled trial comparing the accuracy of glenoid component placement in anatomic total shoulder arthroplasty.

BACKGROUND: Traditional, commercially sourced patient-specific instrumentation (PSI) systems for shoulder arthroplasty improve glenoid component placement but can involve considerable cost and outsourcing delays. The purpose of this randomized controlled trial was to compare the accuracy of glenoid component positioning in anatomic total shoulder arthroplasty (aTSA) using an in-house, point-of-care, 3-dimensionally (3D) printed patient-specific glenoid drill guide vs. standard nonspecific instrumentation. METHODS: This single-center randomized controlled trial included 36 adult patients undergoing primary aTSA. Patients were blinded and randomized 1:1 to either the PSI or the standard aTSA guide groups. The primary endpoint was the accuracy of glenoid component placement (version and inclination), which was determined using a metal-suppression computed tomography scan taken between 6 weeks and 1 year postoperatively. Deviation from the preoperative 3D templating plan was calculated for each patient. Blinded postoperative computed tomography measurements were performed by a fellowship-trained shoulder surgeon and a musculoskeletal radiologist. RESULTS: Nineteen patients were randomized to the patient-specific glenoid drill guide group, and 17 patients were allocated to the standard instrumentation control group. There were no significant differences between the 2 groups for native version (P = .527) or inclination (P = .415). The version correction was similar between the 2 groups (P = .551), and the PSI group was significantly more accurate when correcting version than the control group (P = .042). The PSI group required a significantly greater inclination correction than the control group (P = .002); however, the 2 groups still had similar accuracy when correcting inclination (P = .851). For the PSI group, there was no correlation between the accuracy of component placement and native version, native inclination, or the Walch classification of glenoid wear (P > .05). For the control group, accuracy when correcting version was inversely correlated with native version (P = .033), but accuracy was not correlated with native inclination or the Walch classification of glenoid wear (P > .05). The intraclass correlation coefficient was 0.703 and 0.848 when measuring version and inclination accuracy, respectively. CONCLUSION: When compared with standard instrumentation, the use of in-house, 3D printed, patient-specific glenoid drill guides during aTSA led to more accurate glenoid component version correction and similarly accurate inclination correction. Additional research should examine the influence of proper component position and use of PSI on clinical outcomes.

Premorbid glenoid anatomy reconstruction from contralateral shoulder 3-dimensional measurements: a computed tomography scan analysis of 260 shoulders.

BACKGROUND: Total shoulder arthroplasty (TSA) aims to reconstruct the premorbid anatomy of a pathologic shoulder. A healthy contralateral shoulder could be useful as a template in planning TSA. The symmetry between the left and right shoulders in healthy patients remains to be proved. The purpose of this study was to compare the 3-dimensional anatomy of the glenoid between sides in a healthy population. METHODS: A multinational computed tomography scan database was retrospectively reviewed for all healthy bilateral shoulders in patients aged between 18 and 50 years. One hundred thirty pairs of healthy shoulder computed tomography scans were analyzed, and glenoid version, inclination, width, and height, as well as glenoid lateral offset and scapula lateral offset, were measured. All anatomic measures were computed with Blueprint, validated 3-dimensional planning software. The intraclass correlation coefficient was determined for each measure between left and right shoulders. The minimal detectable change (MDC) was calculated using the following formula: MDC=2×1.96×Standarderrorofmeasurement. RESULTS: The comparison between 130 pairs of healthy scapulae showed statistically significant differences in absolute values between right and left glenoid version (-5.3° vs. -4.6°, P < .01), inclination (8.4° vs. 9.3°, P < .01), and width (25.6 mm vs. 25.4 mm, P < .01), as well as scapula offset (105.8 mm vs. 106.2 mm, P < .01). Glenoid height was comparable between right and left shoulders (33.3 mm vs. 33.3 mm, P = .9). The differences between the means were always inferior to the MDC regarding glenoid version, inclination, height, and width, as well as scapula offset. Very strong intraclass correlation coefficients between the left and right shoulders were found for all evaluated paired measures. CONCLUSION: Healthy contralateral scapulae are highly reliable to predict inclination, height, width, and scapula offset and are reliable to predict version of a given scapula. Paired right and left scapulae were not statistically symmetrical regarding mean glenoid version, inclination, and width, as well as scapula offset. Nevertheless, the reported differences were not higher than the MDC for this cohort, confirming that healthy contralateral shoulders can be a useful template in TSA preoperative planning.

A scapular statistical shape model can reliably predict premorbid glenoid morphology in conditions of severe glenoid bone loss.

BACKGROUND: Knowledge of premorbid glenoid parameters at the time of shoulder arthroplasty, such as inclination, version, joint line position, height, and width, can assist with implant selection, implant positioning, metal augment sizing, and/or bone graft dimensions. The objective of this study was to validate a scapular statistical shape model (SSM) in predicting patient-specific glenoid morphology in scapulae with clinically relevant glenoid erosion patterns. METHODS: Computed tomography scans of 30 healthy scapulae were obtained and used as the control group. Each scapula was then virtually eroded to create 7 erosion patterns (Walch A1, A2, B2, B3, D, Favard E2, and E3). This resulted in 210 uniquely eroded glenoid models, forming the eroded glenoid group. A scapular SSM, created from a different database of 85 healthy scapulae, was then applied to each eroded scapula to predict the premorbid glenoid morphology. The premorbid glenoid inclination, version, height, width, radius of best-fit sphere, and glenoid joint line position were automatically calculated for each of the 210 eroded glenoids. The mean values for all outcome variables were compared across all erosion types between the healthy, eroded, and SSM-predicted groups using a 2-way repeated measures analysis of variance. RESULTS: The SSM was able to predict the mean premorbid glenoid parameters of the eroded glenoids with a mean absolute difference of 3° ± 2° for inclination, 3° ± 2° for version, 2 ± 1 mm for glenoid height, 2 ± 1 mm for glenoid width, 5 ± 4 mm for radius of best-fit sphere, and 1 ± 1 mm for glenoid joint line. The mean SSM-predicted values for inclination, version, height, width, and radius were not significantly different than the control group (P > .05). DISCUSSION: An SSM has been developed that can reliably predict premorbid glenoid morphology and glenoid indices in patients with common glenoid erosion patterns. This technology can serve as a useful template to visually represent the premorbid healthy glenoid in patients with severe glenoid bony erosions. Knowledge of the premorbid glenoid preoperatively can assist with implant selection, positioning, and sizing.

The impact of 3-dimensional humeral planning and standard transfer instrumentation on reconstruction of native humeral anatomy for anatomic total shoulder arthroplasty.

BACKGROUND: Preoperative 3-dimensional (3D) computed tomography (CT)-based planning for anatomic total shoulder arthroplasty (TSA) has grown in popularity in the past decade with the primary focus on the glenoid. Little research has evaluated if humeral planning has any effect on the surgical execution of the humeral cut or the positioning of the prosthesis. METHODS: Three surgeons performed a prospective study using 3D-printed humeri printed from CTs of existing patients, which were chosen to be -3, -1, 0, 1, and 3 standard deviations of all patients in a large database. A novel 3D printing process was used to 3D print not only the humerus but also all 4 rotator cuff tendons. For each surgical procedure, the printed humerus was mounted inside a silicone shoulder, with printed musculature and skin, and with tensions similar to human tissue requiring standard retraction and instruments to expose the humerus. Three phases of the study were designed. In phase 1, humeral neck cuts were performed on all specimens without any preoperative humeral planning; in phase 2, 3D planning was performed, and the cuts and implant selection were repeated; in phase 3, a neck-shaft angle (NSA) guide and digital calipers were used to measure humeral osteotomy thickness to aid in the desired humeral cut. All humeri were digitized. The difference between the prosthetic center of rotation (COR) and ideal COR was calculated. The percentage of patients with a varus NSA was calculated for each phase. The difference in planned and actual cut thickness was also compared. RESULTS: For both 3D change in COR and medial to lateral change in COR, use of preoperative planning alone and with standard transfer instrumentation resulted in a significantly more anatomic restoration of ideal COR. The deviations from planned cut thickness decreased with each phase: phase 1: 2.6 ± 1.9 mm, phase 2: 2.0 ± 1.3 mm, phase 3: 1.4 ± 0.9 mm (P = .041 for phase 3 vs. phase 1). For NSA, in phase 1, 7 of 15 (47%) cases were in varus; in phase 2, 5 of 15 (33%) were in varus; and in phase 3, 1 of 15 (7%) cases was in varus (P = .013 for phase 3 vs. phase 1). CONCLUSIONS: Use of preoperative 3D humeral planning for stemless anatomic TSA improved prosthetic humeral COR, whether performed with or without standard transfer instrumentation. The use of an NSA cut guide and calipers to measure cut thickness significantly reduced the percentage of varus humeral cuts and deviation from planned cut thickness.

Preoperative Joint Distraction Imaging and Planning Protocol for Total Knee Arthroplasty.

BACKGROUND: Current preoperative total knee arthroplasty (TKA) planning strategies are bone-referencing and do not consider the ligamentous profile of the knee. This study assessed the mean Hip-Knee-Ankle (HKA) angle of the planned Distracted Alignment (DA), an alignment output using a joint distraction radiology and planning protocol, which incorporates preoperative evaluation of ligament laxity. METHODS: A retrospective study of 144 knees undergoing TKA was performed. Each patient received a preoperative computer tomograph scan, a weight-bearing antero-posterior knee radiograph, and distracted knee radiographs in extension and flexion. The imaging was used to develop a preoperative DA plan aiming for medio-lateral and extension-flexion space balance. The mean DA, weight-bearing, and arithmetic HKA angles were compared to each other, and to the HKA of a healthy nonarthritic population. RESULTS: The mean weight-bearing, arithmetic, and planned DA HKA angles were 4.8° (interquartile range [IQR] 6.5°) varus, 0.4° (IQR 4.5°) varus, and 2.2° (IQR 4.0°) varus, respectively. This compares to a healthy adult HKA angle of 1.3° varus. The difference between the planned DA and arithmetic HKA angles was greater than 3° for 36% of the patients in the study population. CONCLUSIONS: The planned DA HKA angle was fundamentally different from the arithmetic HKA angle, but comparable to a healthy population. Considering both hard and soft tissue information of the knee, we believe the planned DA resulting from the joint distraction radiology protocol allows for optimized preoperative surgical planning in TKA. This protocol has been shown to be clinically viable.

Decreased Instability in High-Risk (Hip-Spine 2B) Patients After Modifications of Surgical Planning and Technique.

BACKGROUND: Patients undergoing primary total hip arthroplasty (THA) who have spinal deformity and a stiff spine are the highest-risk group for instability. Despite the increasing use of dual-mobility cups and large femoral heads, dislocation remains a major complication after THA. Preoperative planning becomes a critical aspect of ensuring precise component positioning within a safe zone. The purpose of this study was to investigate dislocation rates over a 9-year period. METHODS: A retrospective review of 4,731 THAs performed by 3 orthopaedic surgeons between January 2014 and March 2023 was performed. Spinopelvic measurements were conducted to determine the hip-spine classification group for each patient. Only patients classified as 2B (pelvic incidence-lumbar lordosis > 10° and Δsacral slope < 10°) were eligible. Both absolute and relative dislocation frequencies were then analyzed using time-series analysis techniques and Fisher's exact tests. RESULTS: A total of 281 hip-spine 2B patients undergoing primary THA were eligible for analysis (57% women; mean age, range: 66 years, 23 to 87; mean body mass index, range: 28, 16 to 45). The overall dislocation rate was 4.3%. Use of femoral head sizes ≥ 40 mm increased from 4% in 2014 to 2019 to 37% in 2020 to 2023 (P < .001), while the use of dual-mobility cups decreased from 100% in 2014 to 2019 to 37% in 2020 to 2023 (P < .001). Acetabular component planning was changed from the supine plane to the standing plane in February 2020. Those changes in surgical practice were notably correlated with a significant decrease in dislocation rates from 6.8% in 2014 to 2019 to 1.5% in 2020 to 2023 (P = .03). CONCLUSIONS: Our study demonstrates that the introduction of advanced preoperative THA planning to the standing plane, coupled with precise intraoperative technology for implant placement, can significantly reduce the risk of instability in high-risk THA patients. Notably, we observed a significant decrease in dislocation rates, which aligned with the shift in surgical practice. LEVEL OF EVIDENCE: IV.

The Reconstructive Metaverse - Collaboration in Real-Time Shared Mixed Reality Environments for Microsurgical Reconstruction.

Plastic surgeons routinely use 3D-models in their clinical practice, from 3D-photography and surface imaging to 3D-segmentations from radiological scans. However, these models continue to be viewed on flattened 2D screens that do not enable an intuitive understanding of 3D-relationships and cause challenges regarding collaboration with colleagues. The Metaverse has been proposed as a new age of applications building on modern Mixed Reality headset technology that allows remote collaboration on virtual 3D-models in a shared physical-virtual space in real-time. We demonstrate the first use of the Metaverse in the context of reconstructive surgery, focusing on preoperative planning discussions and trainee education. Using a HoloLens headset with the Microsoft Mesh application, we performed planning sessions for 4 DIEP-flaps in our reconstructive metaverse on virtual patient-models segmented from routine CT angiography. In these sessions, surgeons discuss perforator anatomy and perforator selection strategies whilst comprehensively assessing the respective models. We demonstrate the workflow for a one-on-one interaction between an attending surgeon and a trainee in a video featuring both viewpoints as seen through the headset. We believe the Metaverse will provide novel opportunities to use the 3D-models that are already created in everyday plastic surgery practice in a more collaborative, immersive, accessible, and educational manner.

Clinical application of artificial intelligence-assisted three-dimensional planning in direct anterior approach hip arthroplasty.

PURPOSE: The objective of this study was to investigate the efficacy of an artificial intelligence-assisted 3D planning system (AIHIP) in total hip arthroplasty by direct anterior approach and assess the reliability of the AIHIP preoperative program in terms of both interobserver and intraobserver agreement. METHODS: A retrospective analysis was conducted on patients who underwent unilateral primary THA via direct anterior approach from June 2019 to March 2022. Participants were randomly assigned to receive either the AIHIP system (n = 220) or the 2D template (control group) (n = 220) for preoperative planning. The primary outcome aimed to evaluate the correspondence between the prosthesis selected intro-operation and the one planned preoperatively, as well as to calculate the intraclass correlation coefficient (ICC). Secondary outcomes included operation time, intraoperative blood loss, fluoroscopy times, Harris hip score (HHS), lower limb length difference (LLD), femoral offset (FO), and bilateral femoral offset difference. RESULTS: No significant differences were observed in gender, age, body mass index (BMI), aetiology, and American Society of Anesthesiologists (ASA) score between the two groups. Both planning methods exhibited good intraobserver agreement for component planning (ICC: 0.941-0.976). Interobserver agreement for component planning was comparable between the two methods (ICC: 0.882-0.929). In the AIHIP group, the accuracy of acetabular cup and femoral stem prosthetics planning significantly improved, with accuracies within the size range of ± 0 and ± 1 being 76.8% and 90.5% and 79.5% and 95.5%, respectively. All differences between two groups were statistically significant (p < 0.05). Patients receiving AIHIP preoperative planning experienced shorter operation times, reduced intraoperative blood loss, fewer fluoroscopy times, and lower leg length discrepancy (LLD) (p < 0.05). Moreover, they demonstrated a higher Harris hip score (HHS) at three days post-surgery (p < 0.05). However, no significant differences were found in femoral offset (FO), difference of bilateral femoral offsets, and HHS at 1 month after the operation. CONCLUSION: Utilizing AIHIP for preoperative planning of direct anterior approach THA can significantly enhance the accuracy of prosthetic sizing with good reliability, decrease operation time, reduce intraoperative blood loss, and more effectively restore the length of both lower limbs. This approach has greater clinical application value.

Accuracy of two-dimensional digital planning in uncemented primary hip arthroplasty: monocentric analysis of eight hundred implants.

PURPOSE: In the last decades, there has been a refinement in total hip arthroplasty, which allowed surgeons to achieve the highest performance and better patient outcomes. Preoperative planning in primary hip arthroplasty is an essential step that guides the surgeon in restoring the anatomy and biomechanics of the joint. This study aims to evaluate the accuracy of the 2D digital planning, considering cup sizing, stem sizing, and limb length discrepancy. Additionally, we conducted a multivariable analysis of demographic data and comorbidities to find factors influencing preoperative planning. METHODS: This retrospective study analyzed the planning accuracy in 800 consecutive uncemented primary total hip arthroplasty. We compared the preoperatively planned total hip arthroplasty with postoperative results regarding the planned component size, the implanted size, and the lower limb length restoration. Therefore, we investigated factors influencing planning accuracy: overweight and obesity, sex, age, past medical history, comorbidities, and implant design. All the surgeries were performed in the posterolateral approach by one expert surgeon who did the preoperative planning. The preoperative planning was determined to be (a) exact if the planned and the implanted components were the same size and (b) accurate if exact ± one size. The restoration of postoperative limb length discrepancy was classified into three groups: ± 3 mm, ± 5 mm, and ± 10 mm. This assessment was performed through a digital method 2D based on a standard hip X-ray. RESULTS: This court of 800 implants showed that planning was exact in 60% of the cups and 44% of the stems and was accurate in 94% of the cups and 80% of the stems. The postoperative limb length discrepancy was ± 3 mm in 91% and ± 5 mm in 97%. CONCLUSIONS: This study showed preoperative 2D digital planning great precision and reliability, and we demonstrated that it was accurate in 94% of the cups and 80% of the stems. Therefore, the preoperative limb length discrepancy analysis was essential to guarantee the recovery of the operated limb's correct length.

Comparison of virtual reality and computed tomography in the preoperative planning of complex tibial plateau fractures.

INTRODUCTION: Preoperative planning is a critical step in the success of any complex surgery. The pur-pose of this study is to evaluate the advantage of VR glasses in surgical planning of complex tibial plateau fractures compared to CT planning. MATERIALS AND METHODS: Five orthopedic surgeons performed preoperative planning for 30 fractures using either conventional CT slices or VR visualization with a VR headset. Planning was performed in a randomized order with a 3-month interval between planning sessions. A standardized questionnaire assessed planned operative time, planning time, fracture classification and understanding, and surgeons' subjective confidence in surgical planning. RESULTS: The mean planned operative time of 156 (SD 47) minutes was significantly lower (p < 0.001) in the VR group than in the CT group (172 min; SD 44). The mean planning time in the VR group was 3.48 min (SD 2.4), 17% longer than in the CT group (2.98 min, SD 1.9; p = 0.027). Relevant parameters influencing planning time were surgeon experience (-0.61 min) and estimated complexity of fracture treatment (+ 0.65 min). CONCLUSION: The use of virtual reality for surgical planning of complex tibial plateau fractures resulted in significantly shorter planned operative time, while planning time was longer compared to CT planning. After VR planning, more surgeons felt (very) well prepared for surgery.

Intra- and inter-operator reliability of three-dimensional preoperative planning in total knee arthroplasty.

PURPOSE: To characterize the intra- and inter-operator reliability of a CT-based 3D preoperative planning software. MATERIALS AND METHODS: This study analyzed 30 CT scans of de-identified knees with osteoarthritis. For each scan, a case planner segmented the bones and pre-planned the TKA. Three orthopedic surgeons then reviewed each pre-planning three times at least one week apart, in a blinded manner. During the reviews, the surgeons modified the pre-plannings until they felt the plannings matched the objectives defined collegially at the beginning of the study. Reliability was assessed using the Intraclass Correlation Coefficient (ICC) and the Standard Error of Measurement (SEM). RESULTS: The intra- and inter-operator reliabilities for implant size selection were almost perfect (ICC between 0.97 and 0.99). Implants of same sizes were selected in 67.1-90.0% of cases. For implant placements, almost perfect intra- and inter-operator reliability was observed in all degrees-of-freedom (ICC between 0.81 and 1.00), except in flexion-extension for the femur (intra-operator ICC between: 0.76 and 0.99; inter-operator ICC of 0.61) and the tibia (intra-operator ICC between 0.12 and 1.00; inter-operator ICC of 0.03). All implant placements SEM were below 1.3 mm or 1.7°. CONCLUSIONS: This study showed high intra- and inter-operator reliability for implant size selection and, in most of the degrees-of-freedom, also for implant placements. Further research is needed to evaluate the benefit of developing more precise means of describing the objectives of the surgical planning as well as to evaluate the possibility and relevance of adding features in the planning software to assist the operators.

A Cost-Affordable Methodology of 3D Printing of Bone Fractures Using DICOM Files in Traumatology.

Three-dimensional (3D) printing has gained popularity across various domains but remains less integrated into medical surgery due to its complexity. Existing literature primarily discusses specific applications, with limited detailed guidance on the entire process. The methodological details of converting Computed Tomography (CT) images into 3D models are often found in amateur 3D printing forums rather than scientific literature. To address this gap, we present a comprehensive methodology for converting CT images of bone fractures into 3D-printed models. This involves transferring files in Digital Imaging and Communications in Medicine (DICOM) format to stereolithography format, processing the 3D model, and preparing it for printing. Our methodology outlines step-by-step guidelines, time estimates, and software recommendations, prioritizing free open-source tools. We also share our practical experience and outcomes, including the successful creation of 72 models for surgical planning, patient education, and teaching. Although there are challenges associated with utilizing 3D printing in surgery, such as the requirement for specialized expertise and equipment, the advantages in surgical planning, patient education, and improved outcomes are evident. Further studies are warranted to refine and standardize these methodologies for broader adoption in medical practice.