Patient-specific Instrumentation Research Articles

Total Elbow Replacement in Swine: Surgical Technique and Initial Clinical Experience in a Kunekune Sow.

The aim of this study was to describe the development of a total elbow replacement (TER) technique in swine and report the outcome of TER in a Kunekune sow (61 kg) with severe elbow osteoarthritis. The technique was developed by operating on three pig cadavers (Yorkshire 40-50 kg). The TATE Elbow implant fit was confirmed with modeling to the patient's computed tomography imaging. Patient-specific instrumentation was printed for attempted use. Total elbow replacement was performed using a lateral approach, including lateral epicondylar osteotomy, careful retraction of the radial nerve, and preservation of the lateral collateral ligament. Postoperative care included controlled exercise and physical therapy. A lateral approach to the pig elbow for TATE TER was successfully developed. The bulk of the lateral head of the triceps muscle precluded use of the patient-specific instrumentation; the procedure was performed using standard instrumentation. Radiographic evidence up to 9 months postoperatively showed adequate implant alignment and satisfactory osteointegration of humeral and radioulnar components. There were not any postoperative complications and the patient's comfort was improved by 6 months and sustained at 18 months. A lateral approach for TATE TER in a pig with advanced elbow osteoarthritis proved feasible and effective. With the expansion of the TATE Elbow line, it is possible that a larger range of pigs could be treated. This report suggests that a lateral approach for TATE TER in dogs could represent a suitable alternative to the medial approach currently used.

Design Rational for Total Ankle Arthroplasty: An Update

The design of total ankle arthroplasty (TAA) systems is rapidly evolving as device companies try to keep pace with the expansion of surgical indications and a refinement of techniques for TAA. Even since the publication of the latest “update,” published in 2018, three new designs and three updates on preexisting third-generation implants came onto the market. Improvements in third-generation TAA systems include minimal bone resection, retaining ligamentous support, and anatomic balancing. Fourth-generation systems use 3D printing technology, improved talus and tibia designs based on CT scans of arthritic and normal ankles, and include patient-specific instrumentation. We will then explore the short-term and mid-term outcomes of the previously discussed six TAA systems—INBONE, INFINITY, INVISION (Stryker), Salto-Talaris (Smith and Nephew), Scandinavian Total Ankle Arthroplasty (Enovis), Trabecular Metal Total Ankle (Zimmer Biomet), and VANTAGE (Exactech). As more research pours in regarding mid- to long-term outcomes of these implants, it is important to assess the design rationale and summarize current outcome data for these implants.

“In My Experience…A New Age of X-ray-based Patient Specific Instrumentation”

The author writes about his experience with modern Patient Specific Instrumentation.

Advances in Minimally Invasive Joint Replacement Techniques: Redefining Precision and Recovery

Minimally invasive joint replacement (MIJR) techniques have revolutionized orthopedic surgery by significantly reducing recovery times, hospital stays, and complication rates compared to traditional methods. Enhanced by innovations like robotics, augmented reality (AR), and patient-specific instrumentation (PSI), MIJR offers greater surgical precision with less trauma to surrounding tissues. This article explores the latest advancements in MIJR, demonstrating its impact on clinical outcomes and highlighting future trends such as AI-driven surgical planning and biologic implants. MIJR has become the gold standard in joint replacement, providing patients with faster recovery and improved long-term results. Minimally invasive joint replacement (MIJR) techniques have revolutionized orthopedic surgery by significantly reducing recovery times, hospital stays, and complication rates compared to traditional methods. Enhanced by innovations like robotics, augmented reality (AR), and patient-specific instrumentation (PSI), MIJR offers greater surgical precision with less trauma to surrounding tissues. This article explores the latest advancements in MIJR, demonstrating its impact on clinical outcomes and highlighting future trends such as AI-driven surgical planning and biologic implants. MIJR has become the gold standard in joint replacement, providing patients with faster recovery and improved long-term results.

Digital tools in primary total knee arthroplasty-Prevalence in the German-speaking region

Digital tools are being increasingly used worldwide in primary knee arthroplasty. This study aimed to analyze the utilization density of digital tools, the preferred alignment strategies, and the obstacles and benefits of implementing these technologies in German-speaking countries. An online survey with 57questions about digital tools in primary knee arthroplasty and their usage was conducted among members of the Arthroplasty Working Group (AE). The survey included questions on navigation, robotics, patient-specific instruments, individualized implants, and augmented reality. The survey revealed that 18% of hospitals use navigation and 17% use robotic systems in primary total knee arthroplasty surgery. The main reasons for not implementing supportive technologies were high acquisition and ongoing costs, as well as longer surgical duration. Patient-specific instruments and individualized implants currently play aminor role. Patient-specific alignment strategies, such as kinematic (navigation: 35%; robotics: 44%) and functional alignment (navigation: 15%; robotics: 35%), are preferred in this context. With conventional instrumentation predominantly mechanical alignment was applied (79%). The results indicate arelatively high utilization density of digital tools, which are mainly used to perform personalized alignment strategies in primary knee arthroplasty in German-speaking countries. This was particularly evident in high-volume hospitals. Economic aspects were the main reasons for not using these technologies. Future developments should aim to simplify the systems and thus achieve improved cost efficiency.

Comparison of Implant Placement Accuracy Between Manual, Robot-Assisted, Computer-Navigated, Augmented Reality Navigated, Patient-Specific Instrumentation, and Accelerometer Navigated Total Hip Arthroplasty: A Systematic Review and Network Meta-Analysis.

Malpositioning of the acetabular cup during total hip arthroplasty (THA) can lead to complications. Robotic surgery and navigation techniques aim to address this issue, but there is limited evidence regarding which method can achieve better clinical outcomes. Therefore, this network meta-analysis (NMA) aimed to compare the efficacy of various navigation methods. This NMA of prospective randomized controlled trials compared robot-assisted systems (RAS), computer-assisted navigation systems (CAS), augmented reality-based portable navigation (AR), patient-specific instrumentation (PSI), portable accelerometer-based navigation (PN), and conventional methods (C) for THA procedures. We searched MEDLINE, EMBASE, Cochrane, Central Register of Controlled Trials, International Clinical Trials Platform Search Portal, and ClinicalTrials.gov. databases. The primary outcomes included revision surgery and postoperative clinical scores, and the secondary outcomes encompassed cup placement accuracy, acetabular cup placement outliers from the Lewinnek safe zone, surgical time, and complications. We used a Bayesian random-effects NMA, and confidence of evidence was assessed using confidence in NMA. We identified 45 studies including 2,122 patients. We did not find large differences in revision surgery, clinical outcome scores, cup inclination, or anteversion angle accuracy among the modalities. AR, CAS, and PSI exhibited a lower risk of outliers from safe zones than C. In addition, RAS and CAS had a longer surgical time than C. Robotic and navigation tools did not reduce the revision risk or enhance clinical outcomes. AR, CAS, PSI, and PN may decrease the risk of cup placement outliers in safe zones. However, the cup placement accuracy was equivalent, and the surgical time may be longer in RAS and CAS than in C. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Revolutionizing Shoulder Arthroplasty: The Transformative Impact of Extended Reality, Robotics, and Artificial Intelligence on Training, Planning, and Execution

Technological innovations in shoulder arthroplasty could play a major role in addressing problems of implant positioning, stability, and longevity and optimizing patient outcomes. This review discusses the role of extended reality, navigation, patient-specific instrumentation, robotics and artificial intelligence and their applications in training, preoperative planning and intraoperative execution. These nascent technologies have the potential to deliver extraordinary value to patients requiring shoulder arthroplasty but long-term prospective clinical data justifying their mainstream use is currently lacking.

[Translated article] Can 3D-printed patient-specific instruments improve local control and overall survival in pelvic sarcoma? A clinical validation study

Background and objectives 3D-printed patient-specific instruments (PSIs), also known as 3D guides, have been shown to improve accuracy in resection of pelvic tumors in cadaver studies and achieve better surgical margins in vivo. This study evaluates the clinical impact of 3D-printed guides on medium-term local and distant disease control, as well as disease-free and overall survival in patients.Material and methods A cohort study included 25 patients with primary pelvic or sacral sarcomas: 10 in the 3D group and 15 in the control group, with a median follow-up of 47 months. Demographic and clinical data, including tumor histology, stage, resection technique, associated reconstruction, adjuvant therapies, and complications, were evaluated. Surgical margins (free, marginal, and contaminated) and relapse-free and overall survival curves were analyzed.Results The 3D group achieved a higher rate of free margins (80% vs 66.7%, p = 0.345). Local recurrence (50% vs 60%, P=.244) and distant disease relapse (20% vs 47%, p = 0.132) rates were lower in the 3D group. At the end of the follow-up, the 3D group had a higher overall survival rate (60% vs 40%, p = 0.327). The complication rate was similar in both groups, with a deep infection rate of 40%.Conclusions The use of 3D guides in resecting primary pelvic tumors not only achieves a higher rate of free margins compared to conventional techniques but also shows a trend towards higher local, distant, and overall disease-free survival. Further studies with larger sample sizes and higher levels of evidence are necessary to validate these clinical trends.

Hybrid closing-wedge DTO using PSI was selected for a patient wit severe deformity post-fracture malunion, which enable good alignment correction and patient satisfaction

BackgroundHigh tibial osteotomy (HTO) is an effective treatment option for deformity correction after fracture. However, performing precise corrective osteotomy for cases with a severe varus deformity and a significant posterior slope poses a significant challenge. Three-dimensional (3D) bone model construction and patient-specific instrumentation (PSI) created from preoperative Computed tomography (CT) may be useful tools in achieving successful outcome for such cases. The present technique describes a hybrid closing-wedge distal tuberosity tibial osteotomy (Hybrid CWDTO) using two PSIs.MethodsPreoperative planning was performed in 3D with reference to the contralateral normal lower extremity CT taken preoperatively, which was then mirrored for analysis. A full-scale bone model and two PSIs were constructed based on this plan to allow for complex correction. During surgery, osteotomy was performed using these sterilized PSIs as guides.ResultsRadiographic imaging showed that medial proximal tibial angle (MPTA) improved from 68 to 84 degrees and posterior tibial slope (PTS) improved from 19 to 6 degrees. The standing leg radiograph showed a mechanical varus alignment improvement from 12 to 3 degrees. The 2011 Knee Society Scoring system (2011 KSS) improved from 31 to 95 in objective knee indicators, from 10 to 24 in symptoms, from 14 to 40 in patient satisfaction and from 51 to 95 in activities.ConclusionHybrid CWDTO using PSIs is a useful surgical technique for alignment correction post-malunion while also achieving high patient satisfaction. This can assist surgeons in treating complex deformities that are otherwise difficult to treat.

Technology Update in Management of Multi-Ligament Knee Injuries.

Multi-ligament knee injuries present in various combinations of structures around the knee joint, with or without involvement of neurovascular structures, posing significant challenges to the treating physician and therapists. Accurate diagnosis with appropriate surgical intervention and comprehensive rehabilitation to restore function and stability is, therefore, paramount. This article looks at the recent advancements in technology that are aiding in the management of these injuries. An extensive search of literature was done in PubMed, SCOPUS, and Google Scholar on this topic and the necessary information was derived from the relevant articles for this review. The progress made in the field of diagnosis, surgical management, rehabilitation and patient education tools were explored. A wide variety of diagnostic tools exists that are providing a more accurate evaluation of multi-ligament knee injuries both pre-operatively and post operatively. Advances in technology and techniques have aided in transforming their surgical management to a more minimally invasive approach. Patient-specific instrumentation, computer navigation and robotic-assisted surgery are in various stages of development offering enhanced precision and accuracy during ligament reconstruction procedures along with developments in digital technology and artificial intelligence. Advancements in technology have transformed the management of multi-ligament knee injuries, offering new tools and techniques that enhance diagnostic accuracy, surgical precision, and rehabilitation effectiveness. Artificial intelligence and its utility have widened the horizons, while at the same time bringing in the need for regulations necessary to monitor and develop these technologies.

Patient-specific instrumentation improved clinical outcome and implant survival but is not superior compared to conventional total knee arthroplasty: Ten years follow-up of a multicenter double-blind randomized controlled trial.

Patient-specific instrumentation (PSI) is a commonly used technique designed to improve mechanical alignment in total knee arthroplasty (TKA) and was therefore believed to lead to better clinical outcome and implant survival rates compared with conventional instruments (CIs). To date, long-term results comparing these two techniques are not available. This study is a 10-year follow-up of a previous double-blind multicenter randomized controlled trial where PSI was compared with CI. Patients with osteoarthritis of the knee who were candidates for TKA were included. Exclusion criteria were metal near the knee-, ankle- or hip joint, patients with contra-indications for a magnetic resonance imaging (MRI) scan and patients who had previous knee surgery (except arthroscopic meniscectomy). Clinical outcomes were assessed using patient-reported outcome measures (PROMs), and the analysis was performed with a general linear mixed model for repeated measurements. Kaplan-Meier curves were used to compare revision rates. X-rays were obtained and examined by two individual reviewers for any signs of loosening of the components. At a mean follow-up of 10.1 (SD 0.1) years, 129 patients (loss to follow-up 23%) were analysed in this trial. No statistically significant difference between the two groups were found for any of the PROMs and revision rates were comparable, six in the PSI group and three in the CI group (p = 0.29). Two X-rays in the PSI group showed a radiolucent line of the femoral component. At 10-year follow-up, PSI does not lead to better clinical outcome or survival of the prosthesis compared with CI.

Medial Tibial Condylar Valgus Osteotomy improve clinical outcomes and effectively corrects significant Tibial varus deformities without compromising joint line obliquity or patellar heigh

BackgroundTibial condylar valgus osteotomy (TCVO), or Chiba osteotomy, is a recognized procedure for treating advanced knee osteoarthritis in middle-aged individuals. Although its effectiveness is established, limited literature exists on its outcomes for specific conditions such as post-traumatic deformities, Blount disease (BD), and Pagoda-like proximal tibia varus deformities. HypothesisWe hypothesized that TCVO could improve both clinical and radiographic outcomes in patients with severe varus deformities, correcting lower-limb variances while preserving joint line obliquity (JLO) and patellar height in substantial varus deformities. Patients and methodsThis study included 33 patients who underwent TCVO, with etiologies including post-traumatic (26 patients, 78.8%), Blount disease (4 patients, 12.1%), and Pagoda deformities (3 patients, 9.1%). The average age was 32.5 years (standard deviation = 12.8 years). Techniques for deformity correction varied, including Patient Specific Instrumentation (PSI) for 10 patients (30.3%) and locking plate fixation for 13 patients (39.4%). We assessed several radiological parameters such as hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), Caton-Deschamps index (CDI), and proximal posterior tibial angle (PPTA). Patient-reported outcomes, including the Knee injury and Osteoarthritis Outcome Score (KOOS) and simple knee value (SKV), were recorded both pre-operatively and two years post-operatively. ResultsStatistically significant improvements were observed in clinical scores and alignment changes two years post-operatively, including increases in HKA (from 166.1 to 178.4, p < .0001) and MPTA (from 72.4 to 85.1, p < .0001), and a decrease in JLO (from 9.8 to 3.2, p < .0001). No significant changes were noted in JLCA, PPTA, and CDI, with the patellar height remaining stable post-operatively. The achieved corrections closely matched the pre-operative plans. ConclusionTCVO offers significant improvements in radiological and clinical parameters for patients with substantial tibial varus deformities, effectively maintaining JLO and patellar height. Optimal outcomes from TCVO are dependent on careful patient selection and precise execution of surgical techniques. Level of evidenceIII.

New Technologies in the Treatment of Base of Thumb Osteoarthritis.

Symptomatic osteoarthritis (OA) of the first carpometacarpal (CMC) joint is prevalent and debilitating, commonly affecting the elderly and postmenopausal population. This review highlights the latest advancements in the treatment of thumb CMC OA, which historically includes a range of nonsurgical and surgical options without a consensus benchmark. We will focus on innovative and emerging technologies. Nonsurgical treatments typically comprise custom braces and corticosteroid injections. In addition, this review explores advanced approaches such as 3D printed braces, which have improved patient satisfaction, and novel intra-articular injectables such as autologous fat, optimized by ultrasonography to enhance treatment precision and outcomes. Although standard surgical treatments include trapeziectomy, with or without ligament reconstruction and tendon interposition, more recent implant arthroplasty designs show promising long-term survival. Newer interventions include patient-specific instrumentation for metacarpal osteotomies, selective joint denervation, and innovative suspensionplasty devices, all marked by their increased precision and personalized care. However, it is important to note that these novel technologies are not yet established as superior to standard treatments of thumb CMC OA.

Contemporary use of 3D printed jigs and guides for osteotomies around the knee: a systematic review

Background. With improved accessibility of imaging and additive manufacturing, custom targeting guides and jigs are now widely accepted across many areas of orthopaedics. During orthopedic surgery, patient-specific guides assist in the accurate drilling and cutting of bone in conjunction with meticulous pre-operative planning. Given their increased uptake, it is important to define the lessons learned from recent clinical experience, and to document the reported benefits when using this technology intra-operatively. The aim of this review is to evaluate the potential benefits of patient-specific guides for osteotomies about the knee, and to clarify what evidence currently exists to support their use. Methods. A systematic review of PubMed, Embase, and Web of Science was performed for studies investigating the use of intra-operative patient-specific guides for realignment osteotomies about the knee. Randomised controlled trials, non-randomised studies, observational studies, case series, and case reports, as well as in vitro studies, were included. Screening was conducted with the Covidence software, and risk of bias was assessed with the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool. Results. A total of 38 studies satisfied the inclusion criteria: 21 of these included patient-specific instrumentation (PSI) for high tibial osteotomy, 6 with distal femoral osteotomy, 4 — for combined tibial/femoral rotational corrective osteotomies, 4 — in double-level osteotomies, and 6 — for intra-articular osteotomies. The main outcomes reported were accuracy of surgical correction, typically with reference to pre-operative plans, and execution accuracy based on radiographic measurements. Other common outcomes were operative time, intra-operative fluoroscopy, and operative costs. Many studies were observational in nature, with no control groups available for suitable comparison. Conclusions. For corrective osteotomies about the knee, the literature suggests PSI has very strong potential to improve accuracy in achieving pre-operative targets. This was reported for both opening and closing wedge osteotomies of the femur, and for high tibial osteotomy. Some contradictory results have been reported for high tibial osteotomy, based on limited evidence from small studies that in many instances lacked controls for comparative analysis. Additional controlled trials are necessary to confirm the benefits of PSI for osteotomies about the knee, considering it has not yet been conclusively validated. The literature currently available indicates PSI can improve the accuracy of corrective osteotomies about the knee.

Computer modeling and validation testing for glenoid component rotation and optimal glenoid screw angles for reverse shoulder arthroplasty in an Asian population.

Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature. Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests. Average GRA was - 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3mm and 45.5mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01). Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA.

Efficiency assessment of intelligent patient-specific instrumentation in total knee arthroplasty: a prospective randomized controlled trial

BackgroundIn total knee arthroplasty (TKA), the practical use of patient-specific instrumentation (PSI) has been reported previously with both advantage and disadvantage. The application of artificial intelligent (AI) forces overwhelmingly development of medical industries, while the impact of AI on PSI efficiency remains unknown. Thus, this study aimed to assess the efficiency of Intelligent-PSI (i-PSI) in TKA, compared with the conventional instrumentation-TKA (CI).Methods102 late-stage OA patients who met inclusive criteria were recruited in this prospective randomized controlled trial and separated into two groups (i-PSI vs. CI). In both groups, an AI preoperative planning engine was applied for surgery decision making. In CI group, conventional instrumentation was applied for bony resection, while resection of i-PSI group was completed with i-PSI. A convolutional neural network was applied to automatically process computer tomography images and thus produced i-PSI. With the help of three-dimension printing, the workflow of production was largely simplified. AI-driven preoperative planning guided resection and alignment decisions. Resection measurement, perioperative radiography and perioperative clinical outcomes were analyzed to verify efficiency of i-PSI.ResultsIn resection outcomes, smaller deviation of lateral and medial distal femoral resection were found in i-PSI group than CI group (P = 0.032 and 0.035), while no difference was found in other resection planes. In radiography outcomes, postoperative coronal alignments of i-PSI group, including postoperative Hip–knee–ankle axis (HKA) (P = 0.025), postoperative HKA outliners (P = 0.042), Femoral coronal alignment (FCA) (P = 0.019) and Joint line convergence angle (JLCA) (P = 0.043) showed closer to neutral position than CI group. Moreover, Femoral sagittal alignment (FSA) of i-PSI group showed closer to neutral position than CI group(P = 0.005). No difference was found in other alignments. In clinical outcomes, i-PSI group seemed to cost more surgical time than CI group (P = 0.027), while others showed no differences between the two groups.ConclusionIntelligent Patient-specific Instrumentation in TKA achieved simplified production flow than conventional PSI, while also showed more accurate resection, improved synthesis position and limb alignment than conventional instrumentation. Above all, this study proved that i-PSI being an applicable and promising tool in TKA.

Does patient-specific instrument or robot improve imaging and functional outcomes in unicompartmental knee arthroplasty? A bayesian analysis.

This study conducted a Bayesian network meta-analysis (NMA) to compare the imaging and functional outcomes of patient-specific instrument-assisted unicompartmental knee arthroplasty (P-UKA), robot-assisted unicompartmental knee arthroplasty (R-UKA), and conventional unicompartmental knee arthroplasty (C-UKA). A comprehensive search was performed on five electronic databases and major orthopedic journals as of September 24, 2023. We included randomized controlled studies featuring at least two interventions of P-UKA, R-UKA, or C-UKA. Primary outcomes encompassed the deviation angle of hip-knee-ankle angle, as well as the coronal and sagittal plane alignment of femoral and tibial components. Secondary outcomes included patient-reported outcome measures (PROM), surgery time, revision rate, and complication rate. Bayesian framework was employed for risk ratio (RR) or mean deviation (MD) analysis, and treatment hierarchy was established based on rank probabilities. This NMA included 871 knees from 12 selected studies. In sagittal plane, R-UKA exhibited a significantly reduced deviation angle of femoral component compared to P-UKA (MD: 4.16, 95% CI: 0.21, 8.07), and of tibial component in comparison to C-UKA (MD: -2.45, 95% CI: -4.20, -0.68). Notably, the surgery time was significantly longer in R-UKA than in C-UKA (MD: 15.98, 95% CI: 3.11, 28.88). However, no significant differences were observed in other outcomes. Compared with P-UKA or C-UKA, R-UKA significantly improves the femoral and tibial component alignment in the sagittal plane, although this does not translate into discernible differences in functional outcomes. Comprehensive considerations of economic and learning costs are imperative for the judicious selection of the appropriate procedure.

Management of Extra-Articular and Intra-Articular Distal Radius Malunion.

This article presents a comprehensive overview of managing extra-articular and intra-articular distal radius malunions (DRM), discussing the pathoanatomy, clinical, and radiologic evaluation, conservative treatment, and surgical strategies. Corrective osteotomy remains the primary surgical intervention for symptomatic DRM. Surgical planning should consider factors such as timing, approach, correction technique, implant, graft, and associated injuries. The correction of extra-articular malunion necessitates brachioradialis tenotomy, circumferential periosteum release, and intrafocal elevation with grafting to facilitate distal radius realignment following osteotomy. Computer-assisted planning with 3D-printed patient-specific instrumentation (PSI) could help execute extra-articular osteotomy with high precision. As for the management of intra-articular malunion, it may require wrist arthrotomy, arthroscopy, or PSI assistance for precise articular osteotomy and reduction of the joint surface. This review highlights the importance of early intervention, thorough preoperative planning, and appropriate surgical techniques to optimize outcomes and minimize complications. Future research should focus on large-scale randomized controlled trials to compare different surgical methods, particularly for intra-articular DRM.

Implantation of Reverse Shoulder Endoprothesis Using Navigation.

The implantation of a reverse shoulder arthroplasty (RSA) is a proven method for pain relief and improvement in shoulder function. Results vary, depending on the patient's age, the severity of the disease, and the experience of the surgeon. Indications for RSA are diverse, ranging from rotator cuff arthropathy to fractures. Recent studies show improved survival rates and reduced complications after primary implantation. Preoperative planning using 3D-CT or MRI is considered to be the gold standard. Patient-specific instruments (PSI) have been introduced, but are associated with costs and waiting times. Navigation with augmented reality (AR) provides a more efficient alternative. The intraoperative transfer of the plan to the patient is carried out via AR glasses, allowing real-time information without having to divert the surgeon's attention from the surgical site. This optimises the workflow and potentially yields more precise implantation results. In summary, the combination of 3D planning, navigation, and AR offers a promising method for precise and efficient RSA-implantations. Nevertheless, long-term results and functional scores are not yet available.

Patient-specific guides for consistently achieving R0 bone margins after resection of primary malignant bone tumors of the pelvis

AimsPrimary malignant bone tumor of the pelvis is an uncommon lesion, the resection of which via freehand osteotomy is subject to inaccuracy due to its three-dimensional anatomy. Patient-Specific Guides (PSG), also called Patient-Specific Instruments (PSI) are essential to ensure surgical planning and resection adequacy. Our aim was to assess their use and effectiveness.MethodsA monocentric retrospective study was conducted on 42 adult patients who underwent PSG-based resection of a primary malignant bone tumor of the pelvis. The primary outcome was the proportion of R0 bone margins. The secondary outcomes were the proportion of overall R0 margins, considering soft-tissue resection, the cumulative incidence of local recurrence, and the time of production for the guides. A comparison to a previous series at our institution was performed regarding histological margins.ResultsUsing PSGs, 100% R0 safe bone margin was achieved, and 88% overall R0 margin due to soft-tissue resection being contaminated, while the comparison to the previous series showed only 80% of R0 safe bone margin. The cumulative incidences of local recurrence were 10% (95% CI: 4–20%) at one year, 15% (95% CI: 6–27%) at two years, and 19% (95% CI: 8–33%) at five years. The median overall duration of the fabrication process of the guide was 35 days (Q1–Q3: 26–47) from the first contact to the surgery date.ConclusionsPatient-Specific Guides can provide a reproducible safe bony margin.