Comparison of Blunt Force (Mechanical), Piezoelectric, and Electric Instruments in Bony Vault Management.

The reshaping of the nasal pyramid has evolved significantly over the past 20 years. Mechanical instruments have been refined to minimize the bone trauma of osteotomies. However, these instruments can inadvertently cause radiated fractures and comminuted fractures, which compromise bone stability and can create surface defects. Electric and piezoelectric instruments (PEI) have been developed to address these issues. PEI instruments are selective unlike electric instruments. These instruments allow for precise rhinosculpture and osteotomies under direct visual control. The article reviews the advantages and disadvantages of each method by comparing them for the most frequently performed procedures on the nasal bone pyramid in rhinoplasty.

Comparison of the deformity reduction device (DRD) mini and the Slocum jig in the precision of torsional correction during distal femoral osteotomies in small to medium breed dogs.

Previous studies have compared the use of the Slocum- jig to the deformity reduction device (DRD) jig for the correction of distal femoral deformities of varying degrees in the frontal plane. The objective of the current study is to further investigate the use of the mini DRD jig in comparison to the Slocum jig for correction of varying degrees of torsional deformities of the distal femur. Femoral models (n = 60) were developed based on a CT scan of an approximately 16.5 kg normal canine femur. Models were created with a standard varus deformity of 15 degrees, and external torsional deformities of 15, 20, or 30 degrees. Using center of rotation of angulation (CORA) methodology, corrective osteotomies were planned and performed on each of the 3D printed models based on the group assigned. Modeling clay was applied the proximal femur to mimic visualization of a routine lateral surgical approach, while retaining the ability to palpate surgical landmarks. Post-correction anatomic lateral distal femoral angle (aLDFA) and femoral torsion angle (FTA) were measured and recorded. The mean post-correction FTA of groups using the DRD jig for correction were consistently closer to the ideal value compared to those using the Slocum jig, although these differences were not always statistically significant. Correction of external torsion between the DRD jig and the Slocum jig was significantly different in groups 1 and 2 (P = 0.026 and P = 0.046), but not in group 3. For the correction of varus deformity, no significant difference was found between the two jig types in any group. Results of this study suggest jig selection during distal femoral osteotomy for correction of torsional deformity may result in varying precision of post-correction alignment. Clinical significance of this variance remains unclear, and intra-operative visual assessment of alignment should be implemented to guide corrections.

Pin fixation is an effective method for fixation of bunion osteotomy with various procedures: a retrospective cohort study.

BACKGROUND: Various fixation devices are available for bunion osteotomy. In this study, we evaluated the radiographic outcomes, postoperative complications, and recurrence rate in a series of hallux valgus deformities treated with various osteotomy procedures using a pin for the fixation of the osteotomy. METHODS: Two-hundred forty-seven patients with hallux valgus deformity managed with a Simple, Effective, Rapid and Inexpensive (SERI) osteotomy, distal chevron osteotomy, or proximal crescentic osteotomy and K-wire fixation were included. The mean follow-up of the patients was 53.9 ± 8.9 months. Radiographic evaluations included the assessment of the Hallux valgus angle (HVA), intermetatarsal angle (IMA), and union. Clinical evaluations included the assessment of the range of motion, pain in the first metatarsophalangeal joint, and patient satisfaction. RESULTS: In the last visit, the mean improvement of HVA was 23.9 ± 9.1º (P < 0.001). The mean IMA improvement was 6.1 ± 6º (P < 0.001). The mean metatarsophalangeal flexion and extension were 33 ± 10.7º and 34.6 ± 9.2º, respectively. Postoperative complications included pin tract infection in eight (3.2%) patients, deep infection in five (2%) patients, and early pin complication in four (1.6%) patients. Recurrence was observed in five (2%) patients. Twenty-three (9.3%) patients had slight pain in the last follow-up. The mean surgical time was smaller in the SERI osteotomy (P < 0.001). The mean hospitalization period was longer in the proximal osteotomy group (P = 0.039). The mean metatarsophalangeal flexion and extension were significantly smaller in the distal chevron osteotomy (P = 0.046 and P = 0.037, respectively). 90% of patients were satisfied or very satisfied with the surgical outcomes. CONCLUSION: K-wire fixation is a safe and effective device for the fixation of bunion osteotomy, and this effectiveness is even higher with SERI and proximal crescentic osteotomy.

Step-cut osteotomy for cubitus varus deformity with application of patient-specific instrument in children: a preliminary report.

PURPOSE: The step-cut osteotomy has been recognized as a valuable approach for addressing cubitus varus deformity, albeit one that necessitates technical proficiency. This study aims to evaluate the efficacy of the modified step-cut osteotomy technique in conjunction with patient-specific instruments by clinical and radiological assessment. METHODS: We conducted a retrospective review of patients who underwent modified step-cut osteotomy with the use of patient-specific instruments in conjunction with Kirschner wires fixation for the correction of cubitus varus deformity between April 2016 and April 2022. Follow-up was performed for a minimum of two years, during which pre-operative and post-operative clinical and radiological parameters were compared. RESULTS: Fifteen patients were enrolled in this study. The mean pre-operative humeral-elbow-wrist (HEW) of the affected side was -21.7° (ranging from -14° to -34°), while the normal side was 9.4° (ranging from 5° to 15°). The post-operation HEW of affected side was 9° (ranging from 4° to 16°). There was no significant difference between the normal side and affected side after operation (p = 0.74). Pre-operative range of motion in the affected side was 130°, while the post-operative range of motion was 132°. Fourteen patients (93.3%) were pleased with the overall appearance of their elbow. None lazy-S deformity was observed in these cases. There were no major complications. CONCLUSION: The modified step-cut osteotomy technique, utilizing patient-specific instrument in conjunction with Kirschner wires fixation was found to be a safe, reliable, and technically easy procedure for correcting cubitus varus deformity.

A meta-analysis comparing complications of anterior versus dorsal osteotomy and plating for distal radial malunions.

This systematic review and meta-analysis compare the incidences of complications, reoperations and hardware removal between anterior and dorsal plating after corrective osteotomy for dorsally angulated distal radial malunions. A total of 403 patients were included; 253 patients underwent anterior corrective osteotomy and 150 underwent dorsal corrective osteotomy. Mean follow-up was 30 months. Anterior plating was associated with fewer reoperations (9% vs. 28%), less hardware removal (3% vs. 18%) and comparable major complications (5% vs. 6%) compared to dorsal plating. The adjusted model showed a significant reduction (approximately 85%) in the odds of reoperation and hardware removal in the anterior group. There was no difference in major or minor complications between the groups. Surgeons should be fully aware of the increased risks when using dorsal plate fixation after corrective osteotomy for dorsally angulated distal radial malunions.

A new guide for enhancing dental implant placement: an in vitro assessment of accuracy.

This study aimed to design a new surgical guide for controlling the mesiodistal distance between implant osteotomies and adjacent teeth as well as the osteotomy depth in partially edentulous patients. The guide kit was designed with design software and milled with a CNC (computer numerical control) router. The guide consisted of 2 components-stoppers and crown guides-for determining the drilling depth and mesiodistal position, respectively. The stoppers were designed in 7.5-, 9.5-, and 11.5-mm lengths, and the crown guides were fabricated with outer diameters of 5.0, 6.0, 7.0, and 8.0 mm. The accuracy of the guide was assessed by preparing a total of 20 implant osteotomies in 4 partially edentulous models and comparing the dimensions of the actual osteotomies to the values that were predicted to occur with the use of the surgical guides. Osteotomies were prepared using the 7.5-mm stopper with either the 7.0- or 8.0-mm crown guide. Cone beam computed tomography (CBCT) was used to obtain images for analysis of osteotomy-tooth mesiodistal distances, which were predicted to be 3.0 or 5.5 mm, depending on position; interosteotomy mesiodistal distances, which were predicted to be 3.0 mm; and osteotomy depth, which was predicted to be 11.5 mm. A 1-sample t test was used to determine if there were significant differences between the predicted values and the measurements of the guided osteotomies on the CBCT images of the mandibular models, and an independent t test was conducted to compare the results of 3.0- and 5.5-mm osteotomy-tooth distances (α = 0.05). Differences between the predicted and actual values of the interosteotomy mesiodistal distance (P = 0.516) and osteotomy depth (P = 0.847) were not statistically significant. The actual osteotomy-tooth mesiodistal distances were significantly different from the predicted values of 3.0 (P = 0.000) and 5.5 mm (P = 0.001), with higher mean differences of 0.46 and 0.60 mm, respectively. The designed guide had a high accuracy in achieving optimal linear interosteotomy mesiodistal distances and osteotomy depths, and the obtained mean values were clinically acceptable.

Intelligent electromagnetic navigation system for robot-assisted intraoral osteotomy in mandibular tumor resection: a model experiment.

Background: Mandibular tumor surgery necessitates precise osteotomies based on tumor boundaries; however, conventional osteotomies often lack accuracy in predicting osteotomy positions and planes, potentially leading to excessive resection of normal bone tissues or residual tumors, thus compromising postoperative quality of life and clinical outcomes. Robotic-assisted surgery (RAS) augmented with artificial intelligence (AI) offers precise localization capabilities, aiding surgeons in achieving accurate osteotomy positioning. This study aimed to evaluate the feasibility and accuracy of a robotic magnetic navigation system for positioning and osteotomy in an intraoral surgical trial of a mandibular tumor model. Methods: Patient computed tomography (CT) imaging data of mandibular chin and body tumors were utilized to create 3D printed models, serving as study subjects for mandibular tumor resection. Ten pairs of models were printed for the experimental and control groups. The experimental group (EG) underwent osteotomy using a robot-assisted surgical navigation system, performing osteotomy under robotic navigation following alignment based on preoperative design. The control group (CG) underwent traditional surgery, estimating osteotomy position empirically according to preoperative design. Postoperative CT scans were conducted on both models, and actual postoperative results were compared to preoperative design. Osteotomy accuracy was evaluated by positional and angular errors between preoperatively designed and actual osteotomy planes. Results: For ten randomly selected spots on the left and right sides, respectively, the EG group had mean distance errors of 0.338 mm and 0.941 mm. These values were obtained from the EG group. In the EG group, on the left side, the mean angular errors were 14.741 degrees, while on the right side, they were 13.021 degrees. For the 10 randomly selected spots on the left and right sides, respectively, the CG had mean distance errors of 1.776 mm and 2.320 mm. This is in contrast to the results obtained by the EG. It was determined that the left side had a mean angle error of 16.841 degrees, while the right side had an error of 18.416 degrees in the CG group. The above results indicated significantly lower point errors of bilateral osteotomy planes in the experimental group compared to the control group. Conclusion: This study demonstrates the feasibility of electromagnetic navigation robot-assisted intraoral osteotomy for mandibular tumors and suggests that this approach can enhance the precision of clinical surgery.

Robot-Assisted Augmented Reality (AR)-Guided Surgical Navigation for Periacetabular Osteotomy.

Periacetabular osteotomy (PAO) is an effective approach for the surgical treatment of developmental dysplasia of the hip (DDH). However, due to the complex anatomical structure around the hip joint and the limited field of view (FoV) during the surgery, it is challenging for surgeons to perform a PAO surgery. To solve this challenge, we propose a robot-assisted, augmented reality (AR)-guided surgical navigation system for PAO. The system mainly consists of a robot arm, an optical tracker, and a Microsoft HoloLens 2 headset, which is a state-of-the-art (SOTA) optical see-through (OST) head-mounted display (HMD). For AR guidance, we propose an optical marker-based AR registration method to estimate a transformation from the optical tracker coordinate system (COS) to the virtual space COS such that the virtual models can be superimposed on the corresponding physical counterparts. Furthermore, to guide the osteotomy, the developed system automatically aligns a bone saw with osteotomy planes planned in preoperative images. Then, it provides surgeons with not only virtual constraints to restrict movement of the bone saw but also AR guidance for visual feedback without sight diversion, leading to higher surgical accuracy and improved surgical safety. Comprehensive experiments were conducted to evaluate both the AR registration accuracy and osteotomy accuracy of the developed navigation system. The proposed AR registration method achieved an average mean absolute distance error (mADE) of 1.96 ± 0.43 mm. The robotic system achieved an average center translation error of 0.96 ± 0.23 mm, an average maximum distance of 1.31 ± 0.20 mm, and an average angular deviation of 3.77 ± 0.85°. Experimental results demonstrated both the AR registration accuracy and the osteotomy accuracy of the developed system.

Clinical outcome after open-wedge high tibial osteotomy: comparison of double-triangle locking compression plate (DT-LCP) and T-shaped locking compression plate (T-LCP).

BACKGROUND: The objective of this study was to compare the clinical outcomes of two internal fixation methods for high tibial osteotomy (HTO): double-triangle locking compression plate (DT-LCP) and T-shaped locking compression plate (T-LCP). METHODS: 202 adult patients in our hospital between January 2018 and December 2021 were included and followed up for at least one year: group 1(DT-LCP, 98 patients) and group 2 (T-LCP, 104 patients). Detailed information on demographics, preoperative and postoperative follow-up, surgical procedures, and complications were collected. The information of the International Knee Documentation Committee Knee Evaluation Form (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were collected before surgery and at the last follow-up. RESULTS: A total of 202 patients were included in the per-protocol analysis. No significant difference was found in terms of demographic data between groups, except for age and BMI. Clinically relevant improvements in knee pain were reached up to last follow-up after the operation in both groups. The mean pain scores (KOOS, WOMAC) at the final follow-up were significantly higher among group 1 compared to group 2 (P = 0.040 and P = 0.023). Furthermore, the DT-LCP internal fixation exerted more excellent effects on other symptoms, function and quality of life than T-LCP internal fixation. CONCLUSIONS: Our study demonstrated that DT-LCP provided better clinical performance due to its implant irritant pain, compared with T-LCP. Thus, DT-LCP is a feasible alternative for the fixation of OW-HTO.

Improvement of absorbability, osteoconductivity, and strength of a ß-tricalcium phosphate spacer for opening wedge high tibial osteotomy: clinical evaluations with 106 patients.

BACKGROUND: An ideal synthetic spacer for medial opening wedge high tibial osteotomy (MOWHTO) has not yet been developed. The authors have developed a new ß-tricalcium phosphate (ß-TCP) spacer with 60% porosity (N-CP60) by modifying the micro- and macro-pore structures of a conventional ß-TCP spacer (CP60) that is widely used in clinical practice. The purpose of this study was to compare the absorbability, osteoconductivity, and in vivo strength of the N-CP60 spacer with those of the CP60 spacer, when used in MOWHTO. METHODS: First, the porosity, diameter distribution of macro- and micropores, and compressive strength of each ß-TCP block were examined using methodology of biomaterial science. Secondly, a clinical study was performed using a total of 106 patients (106 knees) with MOWHTO, who were followed up for 18 months after surgery. In these knees, the N-CP60 and CP-60 spacers were implanted into 49 tibias and 57 tibias, respectively. The absorbability and osteoconductivity were radiologically evaluated by measuring the area of the implanted spacer remaining unabsorbed and assessing with the Hemert's score, respectively. The incidence of cracking in the implanted spacers was determined using computed radiography. Statistical comparisons were made with non-parametric tests. The significance level was set at p = 0.05. RESULTS: The N-CP60 and CP60 blocks had almost the same porosity (mean, 61.0% and 58.7%, respectively). The diameter of macropores was significantly larger (p < 0.0001) in the N-CP60 block than in the CP60 block, while the diameter of micropores was significantly smaller (p = 0.019) in the N-CP60 block. The ultimate strength of the N-CP60 block (median, 36.8 MPa) was significantly greater (p < 0.01) than that of the CP60 block (31.6 MPa). As for the clinical evaluations, the absorption rate of the N-CP60 spacer at 18 months after implantation (mean, 48.0%) was significantly greater (p < 0.001) than that of the CP60 spacer (29.0%). The osteoconductivity of the N-CP60 spacer was slightly but significantly higher (p = 0.0408) than that of the CP60 spacer only in zone 1. The incidence of in vivo cracking of the posteriorly located N-CP60 spacer at one month (mean, 75.5%) was significantly lower (p = 0.0035) than that of the CP60 spacer (91.2%). CONCLUSIONS: The absorbability, osteoconductivity, and compressive strength of the new N-CP60 spacer were significantly improved by modifying the macro- and micro-pore structures, compared with the conventional CP60 spacer. The N-CP60 spacer is more clinically useful than the CP60 spacer. TRIAL REGISTRATION NUMBER: H29-0002.

Vertical Mouth Opening Requirements for CAD/CAM Fully Guided Implant Surgery: An Analysis of Different Implant Systems.

PURPOSE: To determine the vertical space required for implant osteotomy preparation when utilizing a CAD/CAM fully guided surgical template. MATERIALS AND METHODS: A total of 14 surgical osteotomy drills (individual and sequential drills) were collected and measured individually using a digital caliper, as well as the total length when the drills were positioned in a surgical handpiece. The height of the surgical guide sleeves and the offset of 14 implant systems in the market were also collected. RESULTS: The vertical dimension of the drills included in this study ranged from 28.2 to 46.3 mm. When these drills were inserted into the handpiece, the total length ranged from 30.0 to 49.5 mm. The height of the surgical guide sleeve and the offset required for the guide had a range of 3.2 to 7.0 mm and 5.0 to 13.5 mm, respectively. This dimension resulted in the total vertical space required for CAD/CAM fully guided surgical templates for each implant system, which ranged from 30.0 to 58.5 mm. CONCLUSIONS: Limited mouth opening can pose challenges and limitations in both guided and nonguided dental implant surgery. It can affect the accessibility of surgical implant placement and may result in increased patient discomfort, surgical implant positioning errors, and postoperative complications. Clinicians should determine the patient's mouth opening capabilities during the treatment planning phase prior to deciding on the appropriate implant system to be used and the implant placement technique.

Use of piezoelectric instrumentation in craniofacial surgery.

PURPOSE OF REVIEW: The use of piezoelectric instrumentation is increasingly recognized as an alternative to traditional bone-cutting techniques across a wide array of surgeries. Here, we provide an overview of the technique, including device principles, benefits, and drawbacks. We also review its use in craniofacial surgery. RECENT FINDINGS: Piezoelectric surgery is a minimally invasive bone-cutting system with lower risk of damage to surrounding soft tissue structures. Indications for its use are rapidly expanding across multiple fields, including craniofacial surgery. To date, piezosurgical techniques have been most widely adopted and studied in the contexts of rhinoplasty, orthognathic surgery, and cranioplasty in craniosynostosis. Piezosurgery can facilitate more precise and consistent osteotomies while decreasing morbidities associated with traditional osteotomy techniques. Primary limitations include cost and concerns regarding increased operative times secondary to operator learning curves and decreased cutting efficiency. SUMMARY: Piezoelectric surgery represents an alternative to traditional bone-cutting modalities to improve precision, consistency, and safety of osteotomies. Further research is needed to better understand the efficacy of the technique as well as potential for additional applications.

An Extended Trochanteric Osteotomy Is Necessary for the Removal of Broken Modular Metaphyseal Engaging Femoral Stems.

BACKGROUND: Modular metaphyseal engaging (MME) femoral components in total hip arthroplasty (THA) allow optimized femoral length, offset, and anteversion and are useful in patients with unusual proximal femoral anatomy. Fretting, corrosion, and stem fractures above the modular sleeve are complications associated with these implants. The purpose of this study was to identify failure mechanisms of retrieved MME femoral components at our institution, identify all broken stem cases, and evaluate how often an extended trochanteric osteotomy (ETO) was required for removal. METHODS: All consecutively retrieved MME femoral components from September 2002 to May 2023 were reviewed. Patient demographics, procedure information, component specifications, indications for removal, and requirements for further revision surgery were reviewed. Descriptive statistics were calculated for variables of interest. RESULTS: There were 131 retrieved MME components. The mean age at surgery was 59 years (range, 28 to 75), 49% were women, mean body mass index was 29.4 (range, 20.7 to 33.3), and mean American Society of Anesthesiologists score was 2.4 ± 0.5. There were 102 (78%) stems of 1 design (stem A), and 29 (22%) stems of a different design (stem B). Of 131 components, 10 (7.6%) failed secondary to stem fracture proximal to the modular sleeve. Four of 102 (4%) of stem A and 6 of 29 (21% of stem B) fractured. All broken stems required additional intervention for removal during revision THA, using an ETO (N = 9) or cortical window (N = 1) in which an intraoperative proximal femoral fracture occurred. CONCLUSIONS: Broken MME stems present a challenge for orthopaedic surgeons during revision THA. When a stem fracture occurs above the ingrown sleeve, the distal splines may have osseous interdigitation into the clothespin. Thus, when revising a broken MME stem, an ETO should be performed, and the segment should be long enough to allow distal access.

Piezoelectric device use in sinus osteotomy for equines is feasible but may extend time to accomplish frontonasal bone flap.

OBJECTIVE: Sinus osteotomy is currently performed in equine surgery with conventional surgical methods, such as trephines and oscillating bone saw, leading to subsequent trauma to the bone during cutting. Piezoelectric devices are now used in maxillofacial surgery in humans as a standard tool as it is less traumatic than the oscillating bone saw and shortens the healing period. The aim of this study was to show that the piezoelectric device can be used for equine sinus surgery, compare its use with the oscillating bone saw, and describe the outcome of cases involving osteotomy performed with a piezoelectric surgical device. ANIMALS: 10 horse specimens for cadaveric study and 11 client-owned equines for clinical evaluation. METHODS: Each cadaveric head underwent a frontonasal bone flap on a randomly assigned side with the piezotome and the oscillating bone saw on the opposite side. Surgical time was recorded for every procedure, and gross examination was performed. A Welch t test was used to compare the surgical time between piezoelectric and oscillating saw use. For the clinical study, animals presented for sinonasal surgery at the hospital from March through October 2023 were included. RESULTS: Osteotomy was possible with the piezotome in all animals. Surgical time was significantly increased when using the piezotome in comparison with the oscillating saw (P < .05). All clinical patients were treated adequately for the sinonasal disorder they were presented for using the piezotome instead of the oscillating saw. No adverse effects nor long-term complications related to its use have been noted, and preservation of the surrounding soft tissues was evident. CLINICAL RELEVANCE: The use of a piezoelectric device in equine surgery is feasible. However, the cadaveric study showed an increased surgical time to perform a frontonasal bone flap.

Evaluation of the resection plane three-dimensional positional accuracy using a resection guide directional guidance slot; a randomized clinical trial.

AIM: The study was performed to compare the mandibular resection guide with a directional guidance slot with the conventional guide regarding three-dimensional positional accuracy. MATERIALS AND METHODS: Twenty-six patients with lateral segmental mandibular defects were selected, and randomly allocated into two groups. All defects were managed with preoperative virtual surgical planning. Resection in the test group was conducted using a resection guide with a directional guidance slot, while a conventional resection guide design was utilized in the control group. The linear and angular deviation of the osteotomy planes was analyzed for both groups, along with the accuracy of the insertion of the reconstruction bone block in the resected defect. Data were documented, absolute deviation was calculated, statistical analysis was performed and significance was set at the 5% level. RESULTS: The cases conducted with a directional guidance templet reported a statistically significant difference when compared to the conventional edge-cutting guide regarding the linear and angular spatial osteotomy plane position (P < 0.001). The defect span analysis reported excellent levels of agreement in both groups (ICC = 1.00, ICC = 0.995), however, the difference between the groups was statistically significant (P < 0.001). CONCLUSION: The study demonstrated the enhanced positional accuracy of the resection plane and reconstruction block placement when a directional slot is incorporated in the computer-generated resection guide.

Inferior alveolar nerve injury resulting from different implant rotary instruments: An ex vivo comparative study in human cadaveric mandibles.

The present study aimed to evaluate the degree of nerve injury on inferior alveolar nerve (IAN) by different implant drills resulting from direct canal intrusion into inferior alveolar canal (IAC). A cadaveric study involving 7 human mandibles was performed to evaluate mechanical injury of canal enclosed IAN resulting from different drills. In group 1, osteotomies were created using different drills with 1 mm of intracanal intrusion, simulating accidental drill intrusion into canal. In group 2, drilling was stopped when the tip has breached into IAC, limited by tactile feedback of operator. The depth and width of nerve defects were assessed using optical coherence tomography. A significant difference in defect depth was found (p < 0.001) in group 1. A sinus lift reamer inflicted the least damage (0.068 ± 0.022 mm). It was also found that the mean defect depth was significantly different when a twist drill was used (p = 0.016). Sinus lift reamer can be used safely for osteotomy preparation in mandible when bone height is limited or when radiographic visualization of canal is poor. Bone corticalization around IAC does not provide adequate protection for IAN in the event of accidental intracanal intrusion.

Hinge screw or no hinge stabilization provides decreased stability compared to hinge plate in a biomechanical evaluation of distal femoral derotational osteotomies.

PURPOSE: Derotational distal femoral osteotomy (DFO) is the causal treatment for patients with femoral torsional deformity. The fixation is achieved by a unilateral angle-stable plate. Delayed- or non-unions are one of the main risks of the procedure. An additional contralateral fixation may benefit the outcome. Therefore, we hypothesize that primary stability in DFO can be improved by an additional fixation with a hinge screw or an internal plate. METHODS: Derotational DFO was performed in 15 knees and fixed either with an angle-stable plate only (group 'None'), with an additional lateral screw (group 'Screw') or with an additional lateral plate (group 'Plate'). Biomechanical evaluation was carried out under axial loading of 150 N (partial weight bearing) and 800 N (full weight bearing), followed by internal and external rotation. After linear axial loading in step 1, a cyclic torsional load of 5 Nm was applied under constant axial load in step 2. In step 3, the specimens were unloaded. Micromovements between the distal and proximal parts of the osteotomy were recorded at each step for all specimens. RESULTS: In step 1, the extent of micromovements was highest in group 'None' and lowest in group 'Plate' without being significantly different. In step 2, group 'Plate' showed significantly higher stability, reflected by less rotation and lower micromovements. Increasing the axial load from 150 to 800 N at step 2 resulted in increased stability in all groups but only reached significance in group 'None'. CONCLUSION: An additional contralateral plate significantly increased stability in derotational DFO compared to the unilateral angle-stable plate only. Contrary, a contralateral hinge screw did not provide improved stability. STUDY DESIGN: Experimental study. LEVEL OF EVIDENCE: IV.

Trephination-based autonomous robotic surgery for dental implant placement: A proof of concept.

OBJECTIVES: To present a novel drilling protocol of trephine osteotomy technique for autologous bone grafting with simultaneous implant placement using an autonomous robotic system. METHODS: The novel protocol consists of 1) preoperative procedures: marker fabrication and fixation, data acquisition, and preoperative planning; 2) intraoperative procedures: registration and calibration, and osteotomy and implant placement performed by an autonomous dental implant robot; 3) postoperative procedures: CBCT acquisition and accuracy assessment. RESULT: The protocol was an effective method for implant osteotomy, with no reported intraoperative complications. The implant surgery was successfully completed, and autogenous bone was obtained. Meanwhile, the accuracy of implant placement was clinically acceptable, with minor deviations. CONCLUSIONS: Trephination-based robotic surgery can be successfully implemented in implant osteotomy, which might replace freehand implant surgery and conventional drilling protocol. However, further clinical studies are necessary. CLINICAL SIGNIFICANCE: The main finding of this case is a potential alternative for preserving autogenous bone during implant surgery.

A rare complication of tension band fixation of olecranon osteotomy: Distal migration of K-wire.

Tension band wiring (TBW) is one of the most commonly used fixation techniques to fix olecranon osteotomies. Hardware prominence has been the most commonly reported complication of TBW. However, distal migration of Kirschner (K)-wire after TBW fixation for olecranon osteotomy has not been reported. In this case report, we presented distal migration of K-wire detected nine months after initial surgery in a 46-year-old male patient. The patient was operated on for an intraarticular distal humerus fracture using an olecranon osteotomy. The osteotomy was fixed with TBW fixation. The patient missed routine follow-ups and presented to the outpatient clinic with a complaint of skin irritation at the elbow nine months after the surgery. On radiological examination, distal migration of one K-wire was detected. The K-wire was surgically removed without any complication. Physicians should be aware of possible complications of TBW and remove fixation after fracture union to avoid unexpected complications.

Minimally invasive hallux valgus surgery using 3D printed patient specific instrumentation.

In this technical report study, we describe technique for performing the osteotomy and screw passage in minimally invasive fourth-generation hallux valgus surgery with transverse and akin extra-articular metaphyseal osteotomy (META) using a 3D-printed patient-specific surgical instrumentation guide. In an effort to minimize the learning curve and address the variability associated with technical corrections and screw placement, we have initiated the creation of personalized patient-specific instrumentation guides using 3D printing. Our hypothesis is that this approach will enhance safety, precision, decrease surgical time, and reduce exposure to radiation. Level of Evidence: Level V, expert opinion.