Plane Correction Research Articles

Method of measuring logistics packages volume based on structured light

To address the need for rapid acquisition of package volume in the logistics industry, a method for measuring the volume of logistics packages based on speckle structured light cameras is proposed. This method utilizes an Astra structured light camera to construct a virtual plane. The plane is obtained by fitting a point cloud on the workbench, and a plane correction algorithm is designed to achieve plane correction and obtain a reference plane. The measurement position of the package is determined through depth image processing. An algorithm for projecting the edge point cloud onto the reference plane is proposed, combined with the minimum bounding rectangle algorithm to measure the length and width of the package. The height of the package is measured using a method of precision error compensation. Through experimental verification and uncertainty analysis, this method enables rapid and stable measurement of the volume of regular logistics packages. Additionally, it is also applicable for measuring irregular logistics packages. According to the analysis based on the guide to the uncertainty in the measurement method, the expanded uncertainties of the measured length and width are 3.57 mm, and the expanded uncertainty of the measured height is 2.20 mm, meeting the requirements for parcel volume measurement. This method demonstrates a stable and reliable volume measurement effect, enabling efficient and accurate acquisition of package volume measurement results.

Initial Experience With VELYS Robot-Assisted Total Knee Replacement: Coronal Plane Accuracy and Effect of Robotic Training on Outcomes.

The use of robots for arthroplasty is gaining momentum inrecent times to provide accuracy in bony cuts and alignment. We aimed to study the efficacy of coronal plane correction with a new robotic system (VELYS™Robotic-Assisted Surgery) and also the effect of the learning curve of robot-assisted total knee arthroplasty (RATKA) on outcomes. We hypothesize that the benefits of RATKA are not limited to only surgeons having specific training in robotic knee replacement. A total of 101 RATKAs were performed between November 1, 2022, andDecember 1, 2022, by a surgeon and all the cases were included in this study. The first 50 consecutive knees were considered as 'Cohort I' and the next 51 consecutive knees as 'Cohort II'. The intraoperative robotic registration data and tourniquet time were recorded. On three months follow‑up, Oxford Knee Score and lower limb scannogram were recorded. All the 101 cases achieved the desired coronal plane alignment within 3 degrees from neutral. There was a significant difference in the tourniquet time between the two groups. There was no significant difference in the mean three months post-operative values of coronal and sagittal deformity correction, range of flexion, and Oxford Knee Score between the two groups. The VELYS™​​​​​​​robot-assisted system produces an accurate correction of coronal alignment. As the surgeon's experience increases with the system, there is a reduction in tourniquet time; however, the degree of deformity correction is comparable to that when he had no experience. Hence the benefits of RATKA are not limited to only surgeons having specific training in robotic-assisted knee replacement.

Alignment rod and gap measurement methods achieve comparable alignment correction in opening wedge high tibial osteotomy for varus osteoarthritic knees.

To compare clinical and radiological outcomes of medial opening wedge high tibial osteotomy (MOWHTO) using two different alignment methods: the alignment rod (AR) versus the gap measurement (GM) method. The primary outcome was to report the surgical accuracy of coronal plane corrections in each method. Patients who underwent MOWHTO with either AR or GM method between 2014 and 2022 at a single institution, with a minimum of 2 years of follow-up, were included. The opening gap was gradually spread with an AR under fluoroscopic control in the AR group, whereas the osteotomy site was opened to the value of the measured gap distance in addition to the thickness of the bone saw in the GM group. Radiological assessment of geometric characteristics included hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle and joint line convergence angle. Surgical accuracy, which is the deviation (Δ) between the intended and achieved correction, was compared between both methods. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Scores. A total of 110 patients (n = 110 knees) with a mean age of 54.1 ± 8.4 years were included in the study. Radiological parameters were significantly improved as reflected by HKA correction from 171.6° ± 2.0° to 181.1° ± 2.6° in the AR group and from 171.0° ± 2.3° to 181.1° ± 2.8° in the GM group at 2 years (Intergroup n.s). There was no significant intergroup difference for all radiological parameters and clinical outcomes. There was no intergroup difference in the surgical accuracy as evaluated by Δvalues and absolute Δvalues of both HKA and MPTA (n.s). Comparable correction accuracy was achieved in MOWHTO using either the AR or GM method. The GM method is simple and reliable in achieving the intended correction in MOWHTO. Ⅲ retrospective comparative study.

3D Semi-Automated Analysis of Joint Sparing Charcot-Marie-Tooth Cavovarus Reconstruction Using Preoperative and Postoperative Weightbearing Computed Tomography

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Charcot-Marie-Tooth (CMT) disease is the most common cause of cavus foot. The complex deformities in cavovarus feet of CMT disease are difficult to evaluate. The bone axes of CMT may be difficult to calculate by conventional weightbearing computed tomography (WBCT). For this reason, 3D automated measurements have been used to assess complex anatomy. The aim of this study was to quantitatively assess deformity correction following joint sparing CMT cavovarus reconstruction surgery. This is the first study investigating preoperative and postoperative WBCT findings in CMT feet using semi-automated 3D measurements. Methods: The study was approved by our institutional review board and informed consent was obtained from all patients. Joint sparing CMT surgery was performed with multiple soft tissue releases and bony procedures. Among the 170 cases from May 2021 to May 2023, twenty-nine CMT patients who had both pre- and postoperative WBCTs were retrospectively analyzed. 3D measurements of WBCT were performed using semi-automated software (Bonelogic 2.1, Disior) to investigate changes in sagittal, axial, and coronal parameters. Pre- and postoperative data was compared using a Wilcoxon signed-ranks test and these data were also compared with normative data using a Welch's t-test. Correlation among these sagittal, axial, and coronal parameters were analyzed using Spearman’s rank correlation coefficient test. Results: The sagittal, axial, and coronal malalignment of the hindfoot, and the sagittal and axial malalignment of the forefoot was significantly improved after corrective surgery (P < .05). Sagittal Meary’s angle (from 14.8 degrees to 0.1 degrees), axial talonavicular angle (TNA, from 3.6 degrees to 19.2 degrees), and coronal hindfoot alignment (from 11.0 degrees to -11.1 degrees) showed significant changes postoperatively (P < .001). Hindfoot, forefoot sagittal and forefoot axial parameters reached comparable outcomes compared to normative value (P > .05). Regarding amount of correction, Spearman’s correlation demonstrated that axial Meary’s angle and TNA were most strongly related to improvement in sagittal Meary’s angle and coronal hindfoot alignment. Conclusion: Preoperative and postoperative WBCT measurements demonstrated that joint sparing CMT cavovarus reconstruction significantly improved sagittal, axial, and coronal deformities of CMT, and sagittal Meary’s angle was restored toward normative values. Apparent axial plane correction, the majority of which occurred at the talonavicular joint, had the strongest correlation with deformity correction in multiple planes. This suggests that soft tissue releases and correction of the talonavicular joint may be a key component of a CMT cavovarus foot correction. Figure. (A) CMT surgery with soft tissue releases and bony procedures, (B) Pre- and postoperative radiographic results, and gross photos of the operated right foot of a 17-year-old male patient.

Validation of the Lift-Off Screw Technique in Patients Undergoing Corrective Osteotomy for Malunited Distal Radius Fractures

The purpose of this study was to validate the clinical accuracy of the lift-off screw (LOS) technique for volar tilt correction (VTC) in patients undergoing corrective osteotomy for dorsally angulated distal radius fracture malunions. We conducted a retrospective review of 23 patients with dorsally angulated distal radius fracture malunions treated with corrective osteotomy using the LOS technique. The LOS equation Ls= [tan(Tc) ∗ Lp+ C]/[cos(⍬s)] and standardized intraoperative fluoroscopic images were used to determine and compare the calculated and clinical VTC and final volar tilt. Correlations between the LOS length and the clinical VTC were calculated, as well as between the desired VTC and the correction accuracy. Preoperative volar tilt ranged from-6° to-50° (mean=-22.9° ± 10.6°). The calculated VTC was 32.7° ± 9.4°, and the clinical VTC achieved was 25.8° ± 9.3°. The difference between the clinical and calculated correction was-6.9°, with an average postoperative clinical volar tilt of 2.8° ± 5.7°, compared with a calculated volar tilt of 9.7° ± 4.4°. There was a moderately strong positive correlation between LOS screw length and clinical VTC achieved, and a moderately weak negative correlation between the desired amount of correction and the accuracy of the correction. The LOS technique is a reproducible method to plan the amount of sagittal plane correction during corrective osteotomy surgery for dorsally angulated distal radius fracture malunions. We demonstrate that this technique underestimates the clinical correction achieved by an average of 7°, with larger deformities experiencing greater undercorrection. Undercorrection of volar tilt during corrective osteotomy should be anticipated by surgeons and considered in future implant and cutting guide designs. Therapeutic IV.

TROPIC: Transfascial Oblique Posterior Interbody Correction: Technical Note

Adult spinal deformity is a common problem in today's aging adult population, particularly in the thoracolumbar spine. This can lead to severe pain and disability, leading to a poorer quality of life. Traditionally, open deformity correction has been the mainstay of treatment for these patients as it provides an excellent operative corridor; however, this comes with severe risk and high complication rates. There has been a trend toward more minimally invasive approaches to correct the deformity while preserving the muscle and soft tissue surrounding the bony spine across the fusion. We describe a minimally invasive surgical technique through a Wiltse approach without invading the paraspinal musculature to gain access to the bony spine to perform lumbar interbody fusions and osteotomies. A total of 3 patients were identified for this technical note who underwent the transfascial oblique posterior interbody correction procedure for adult spinal deformity. The patients had severe coronal and rotational imbalances. We were able to achieve adequate correction through an approach without disturbing the spinal musculature and soft tissues. This technique provides benefits of spinal rotational and coronal plane correction and restores lordosis with current advancements of today's technologies without the downsides of an open surgical approach.

A simple and free software-based inferior alveolar nerve protector surgical guide in bilateral sagittal split osteotomy

ObjectivesThis technical note introduces a novel concept of a alveolar inferior nerve protector guide during orthognathic surgery based on a free-software creation and printing. Technical NoteOrthognathic surgery using Virtual Surgical Planning software like Dolphin Imaging ® v 11.9 facilitated a bimaxillary procedure with mandible advancement and occlusal plane correction, later followed by 3D printing of splints. The process involved importing a composite skull with osteotomies into Blender ® software, where solids were added and edited to match Dolphin's osteotomies, ensuring bone contact without distortion. The guide creation was performed adhering to bilateral sagittal split osteotomy principles, maintaining precision, resulting in preserved inferior alveolar nerve and faster operation times compared to non-guided procedures, as demonstrated by postoperative CT scans. ConclusionsIntegrating advanced tools like Blender software into maxillofacial surgery represents a significant advancement. Despite challenges like the absence of specific manuals for this purpose in Blender, using such software offers innovative and cost-effective solutions. Developing user-friendly resources tailored to surgical applications such as a protector guide within Blender can enhance its usability and improve surgical outcomes and patient care, leading to groundbreaking advancements in maxillofacial surgery.

Three-dimensional deformity correction in adolescent idiopathic scoliosis patients: what are the benefits of hybrid apical sublaminar bands versus all-pedicle screws?

The amount of three-dimensional (3D) correction with apical sublaminar band (hybrid-SLB) technique has not been compared to all-pedicle screw instrumentation for adolescent idiopathic scoliosis (AIS) using detailed axial correction metrics or comparable rod types. Our purpose is to compare 3D improvement in AIS deformities following posterior spinal instrumentation and fusion (PSIF) with hybrid-SLB and segmental correction to all-pedicle screw correction. Patients ages 10-18 years with AIS who underwent PSIF between 2015 and 2022 and had preoperative and postoperative EOS imaging were included. Electronic medical records were reviewed for demographic, Lenke classification, operative technique, and 3D EOS data. Average changes in major and minor Cobb angle, axial rotation, thoracic kyphosis, and lumbar lordosis were compared. Ninety-five patients met inclusion criteria with 55 in the hybrid-SLB group (mean age 14.9 ± 1.9 years) and 40 in all-pedicle screw (mean age 14.7 ± 2.1 years). While all-pedicle screw demonstrated greater correction of major (45.7 ± 13.4 vs 37.9 ± 14.3 degrees; P = 0.008) and minor (28.7 ± 13.1 vs 17.8 ± 12.5 degrees; P = 0.001) Cobb angles, hybrid-SLB showed greater increase in T4-T12 kyphosis (13.3 ± 15.3 vs 5.6 ± 13.5 degrees; P = 0.01). Correction of T1-T12 kyphosis, axial rotation, and lumbar lordosis was similar between groups. 3D EOS analysis of AIS patients before and after PSIF revealed that all-pedicle screw constructs had greater overall coronal plane correction and hybrid-SLB had greater thoracic sagittal plane correction. Axial corrective abilities were similar. Hybrid-SLB may have advantages for correction of thoracic lordosis or hypokyphosis. Level of evidence: Level III, retrospective cohort study.

A High Dynamic Range Ion Detector for Multireflection Time-of-Flight Analyzers.

Reflectron-based time-of-flight analyzers rely on subnanosecond detector time response to achieve acceptable resolving power for low-mid-mass, multiple-ion peaks. With the adoption of multireflection analyzers, order of magnitude longer folded ion paths relax restrictions on detector response time, allowing implementation of new technologies that greatly improve dynamic range, detector lifetime, and ion detection efficiency. A detection system is presented, integrated into a multireflection analyzer, that combines 10 keV postacceleration and focal plane correction with a unique BxE focusing, optically coupled detector, preamplification, and dual-channel digitization. Calibration and peak-handling methods are also described. The instrument demonstrated >1 × 104 dynamic range in a single shot, > 100k resolving power, and a relative immunity to detector aging.

Superior accuracy in knee double level osteotomy using a novel hybrid fixation technique compared to conventional double plating.

This study aimed to compare two different double-level knee osteotomy (DLO) fixation techniques. The primary outcome reported the radiological coronal plane correction and its accuracy. The secondary outcomes reported the correction outliers, the clinical outcomes, the 5-year postoperative satisfaction and the complications. A retrospective review of a single surgeon osteotomy database identified 52 cases of DLO between 2011 and 2019, of which 24 cases met the inclusion criteria. Patients were categorised into two groups: the nail-plate (NP) group fixed with a magnetic extendable intramedullary tibial nail and femoral conventional plate, and the double-plate (DP) group fixed with conventional plates (tibia and femur). Radiographic parameters were recorded, including the mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA) and weight-bearing line ratio (Mikulicz %). Surgical accuracy was calculated as the difference between the achieved and the planned correction. Outliers were defined as those with a greater than 10% difference from the planned correction. Simple knee value scores and visual analogue scale for pain were recorded preoperatively and postoperatively at 2 and 5 years. Five-year patient satisfaction was recorded. A total of 24 patients were included: the NP group (n = 12) and the DP group (n = 12). Significant coronal plane corrections were achieved in the NP group for the mean mFTA (preoperative 167.9° ± 3.4° to postoperative 182.1° ± 1.4°), the mean MPTA (preoperative 83.5° ± 2.9° to postoperative 91.3° ± 2.8°) and the mean mLDFA (preoperative 89.8° ± 3.4° to postoperative 85.9° ± 4.4°). Similarly, significant coronal plane corrections were achieved in the DP group for the mean mFTA (preoperative 168.6° ± 4.4° to postoperative 182.2° ± 2°), the mean MPTA (preoperative 84.2° ± 2° to postoperative 88.3° ± 4.1°) and the mean mLDFA (preoperative 90.7° ± 2.9° to postoperative 83.9° ± 1.7°) (all p < 0.05). The mean correction accuracy was higher for the NP versus DP group at 3.4 ± 3.4% versus 7.1 ± 3.9% (intergroup p < 0.05). There were no outliers in the NP group versus two outliers (overcorrected) (16.7%) in the DP group. Significant clinical improvement was reported in both groups at 2 and 5 years postoperatively (all p < 0.05). Superior correction accuracy and no outliers were achieved in hybrid fixation double-level knee osteotomy compared to the conventional double-plating technique. The magnetic extendable nail offers the advantage of fine-tuning the correction postoperatively and could be a potential research template for future designs of postoperative correction implants. Level III, retrospective cohort study.

Poster 369: Medial and Lateral Posterior Tibial Slope in the Skeletally Immature: A Cadaveric Study

Objectives: Increased knee posterior tibial slope (PTS) angle is risk factor for primary and secondary ACL injury. Adult biomechanical research indicates that decreasing the PTS may reduce ACL injuries, and osteotomy techniques have been developed to alter tibia slope to reduce risk of re-injury. Pediatric and adolescent athletes have the highest rates of primary and secondary ACL injury, and many in this age group may have abnormal PTS angle. The purpose of this study was to evaluate PTS in medial and lateral tibial plateaus in large database of CT scans, and to develop normative PTS data in this age group. Methods: IRB approval was waived, as the specimens were donated for research, no genetic information was collected, and there were no plans for family contact. 83 pediatric knee CT scans, ranging from ages 1 to 12, were analyzed using OsiriX imaging software. The PTS was evaluated at two distinct points on sagittal CT sections: (1) At the medial tibia plateau and 2) lateral tibial plateau, both aligned with the central part of on a coronal view of the medial femoral and lateral femoral condyles respectively condyle. Results: The average medial PTS angle was 6.56° ± 3.84° and 6.81° ± 3.62° for the lateral PTS. There was not a significant statistical difference between the medial and lateral PTS (P = 0.6632, determined using an independent-samples t-test and analysis of variance). When plotting the age versus PTS, we observed a positive correlation with the medial PTS (R2 = 0.0385) and a negative correlation with the lateral PTS (R2 = 0.0393). Conclusions: The data demonstrate variability in medial and lateral pediatric PTS and provides normative values for pediatric PTS values. For pediatric patients undergoing ACL surgeries, consideration of increased PTS values that are associated with higher rates of recurrent ACL injury may influence surgical treatment techniques. Correction of increased PTS to lower ACL injury risk is performed in adults with major corrective osteotomy surgery, but such procedures have not been performed in children due to osteotomy-induced damage to growth plates. Due to open growth plates, pediatric patients may be treated with minimally invasive guide growth procedures to lower PTS, with minimal complication risk. Guided growth procedures have a long history of successful alignment correction in the coronal plane. Future animal and clinic studies may also demonstrate the safety and effectiveness of guided growth sagittal plane correction as applied to increased PTS. PTS developmental anatomy and its relationship to ACL injury is crucial for surgical advancements, including the use of low risk guided growth interventions to reduce PTS and ACL injury in pediatric patients with high risk of recurrent injury.

The Longitudinal Effects of Posterior Spinal Fusion with Derotation on Axial Deformity in Adolescent Idiopathic Scoliosis.

Retrospective case series. To characterize the change in angle of trunk rotation (ATR), axial vertebral rotation (AVR), and body surface rotation (BSR) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with en-bloc derotation across multiple postoperative visits. Previous research has documented ATR, AVR, and BSR correction for AIS patients after surgery. However, there is a lack of evidence on the sustainability of this correction over time. This was a retrospective study from a single-center prospective surface topographic registry of patients with AIS, age 11-20 at time of surgery, who underwent PSF with en-bloc derotation. Patients with previous spine surgery were excluded. ATR was measured with a scoliometer, AVR through EOS radiographic imaging, and BSR via surface topographic scanning, Data collection occurred at: preoperative, six-week, three-month, six-month, one-year, and two-year postoperative visits. BSR and AVR were tracked at the preoperative apical vertebral level, and the level with maximum deformity, at each respective timepoint. Generalized estimating equations models were used for statistical analysis. Covariates included age, sex, and body mass index. 49 patients (73.4% female, mean age 14.6±2.2 years, mean preoperative coronal curve angle 57.9°±8.5, and 67% major thoracic) were evaluated. ATR correction was significantly improved at all postoperative timepoints and there was no significant loss of correction. AVR Max and AVR Apex were significantly improved at all timepoints but there was a significant loss of correction for AVR Apex between the six-week and one-year visit (P=0.032). BSR Max achieved significant improvement at the three-month visit. BSR Apex was significantly improved at the three-month and one-year visit. ATR and AVR demonstrated significant axial plane correction at two-years postoperative in patients undergoing PSF for AIS. BSR did not maintain significant improvement by the two-year visit.

Dual Joystick Technique for Reduction of Torsional Profile in Pediatric Supracondylar Humerus Fracture With Delayed Presentation.

Reduction of some modified Gartland type III and IV supracondylar humerus fractures can pose difficulties, especially if they present late to the hospital. Various techniques of reduction have been tried for reducing the supracondylar humerus fracture for sagittal and coronal plane correction. This retrospective study assesses the dual joystick technique's possible effectiveness in achieving an anatomical reduction of the supracondylar humerus fracture. Patients with modified Gartland's type III and IV supracondylar humerus fractures who underwent closed reduction and percutaneous pinning using the dual joystick technique at our trauma center between January 2020 and January 2022 were the subject of a retrospective review. Forty-six patients treated by the above technique who met the inclusion criteria were analyzed at the end of the final follow-up. The mean age of the children was 7.9+/- 2.25 years, with a male predominance at 32:14. The Right upper limb was more involved compared to the left side. The mean injury to hospital presentation was 2.67+/- 1.28 days, and the mean surgical duration was 24.57+/- 13.76 minutes. The average pin spread ratio at the fracture site was 35.17+/- 3.04%. Baumann angle at the final follow-up was 74.83+/- 2.56 degrees. The mean lateral rotation percentage was 2.8+/- 1.3%. 39 patients had excellent cosmetic outcomes, and 42 had excellent functional outcomes, whereas 7 and 4 patients had good cosmetic and functional outcomes, respectively, according to Flynn criteria. In modified Gartland type III and IV fractures with late presentation where reduction is challenging, this technique is shown to be convenient and easily reproducible and helps accomplish near anatomical reduction with reduced lateral rotation percentage and results in excellent to good outcomes.

3D Analysis of Joint-Sparing Charcot-Marie-Tooth Surgery Effect on Initial Standing Foot Alignment.

The complex deformities in cavovarus feet of Charcot-Marie-Tooth (CMT) disease are difficult to evaluate. The aim of this study was to quantify the initial standing alignment correction achieved after joint-sparing CMT cavovarus reconstruction using pre- and postoperative weightbearing computed tomography (WBCT). Twenty-nine CMT cavovarus reconstructions were retrospectively analyzed. Three-dimensional measurements were performed using semiautomated software (Bonelogic 2.1) to investigate changes in sagittal, axial, and coronal parameters. Pre- and postoperative data were compared, along with normative data. Correlation among the preoperative measurements and the amount of correction in sagittal, axial, and coronal parameters were analyzed. The sagittal, axial, and coronal malalignment of the hindfoot, and the sagittal and axial malalignment of the forefoot, was significantly improved after corrective surgery (P < .05). Sagittal Meary angle (from 14.8 to 0.1 degrees), axial talonavicular angle (TNA, from 3.6 to 19.2 degrees), and coronal hindfoot alignment (from 11.0 to -11.1 degrees) showed significant changes postoperatively (P < .001). Hindfoot, forefoot sagittal, and forefoot axial parameters reached comparable outcomes compared with normative value (P > .05). Regarding amount of correction, Spearman correlation demonstrated that axial Meary angle and TNA were most strongly related to improvement in sagittal Meary angle and coronal hindfoot alignment. Preoperative and postoperative WBCT measurements demonstrated that joint sparing CMT cavovarus reconstruction significantly improved sagittal, axial, and coronal deformities of CMT, and sagittal Meary angle was restored toward normative values. Apparent axial plane correction, the majority of which occurred at the talonavicular joint, had the strongest correlation with deformity correction in multiple planes. This suggests that soft tissue releases and correction of the talonavicular joint may be a key component of a cavovarus foot correction. Level IV, retrospective case series.

Oblique anterior column realignment with a mini-open posterior column osteotomy for minimally invasive adult spinal deformity correction: illustrative case.

Adult spinal deformity (ASD) occurs from progressive anterior column collapse due to disc space desiccation, compression fractures, and autofusion across disc spaces. Anterior column realignment (ACR) is increasingly recognized as a powerful tool to address ASD by progressively lengthening the anterior column through the release of the anterior longitudinal ligament during lateral interbody approaches. Here, we describe the application of minimally invasive ACR through an oblique antepsoas corridor for deformity correction in a patient with adult degenerative scoliosis and significant sagittal imbalance. A 65-year-old female with a prior history of L4-5 transforaminal lumbar interbody fusion and morbid obesity presented with refractory, severe low-back and lower-extremity pain. Preoperative radiographs showed significant sagittal imbalance. Computed tomography showed a healed L4-5 fusion and a vacuum disc at L3-4 and L5-S1, whereas magnetic resonance imaging was notable for central canal stenosis at L3-4. The patient was treated with a first-stage L5-S1 lateral anterior lumbar interbody fusion with oblique L2-4 ACR. The second-stage posterior approach consisted of a robot-guided minimally invasive T10-ilium posterior instrumented fusion with a mini-open L2-4 posterior column osteotomy (PCO). Postoperative radiographs showed the restoration of her sagittal balance. There were no complications. Oblique ACR is a powerful minimally invasive tool for sagittal plane correction. When combined with a mini-open PCO, substantial segmental lordosis can be achieved while eliminating the need for multilevel PCO or invasive three-column osteotomies.

Frontal Plane Correction of Hallux Valgus Deformity With a Minimally Invasive Third Generation Tecnique: Short-Term Radiographic Outcomes of a Prospective Case Series

A number of minimally invasive osteotomies have been described for the repair of hallux abducto valgus (HAV) deformities. However, there are no known published studies that evaluate the effects of minimally invasive surgery techniques on the reduction of frontal plane rotation in patients with HAV. The purpose of this study was to assess correction in the transverse and frontal planes in patients undergoing surgical repair of HAV deformity utilizing a modified percutaneous technique. One hundred and five feet in 105 patients with HAV deformity were treated with a third generation minimally invasive technique using a first metatarsal osteotomy that allowed for frontal plane correction in conjunction with an Akin osteotomy. The minimum follow-up time was 12 months. Preoperative and postoperative anteroposterior weightbearing x-ray images were assessed and four measurements were evaluated: hallux abductus angle (HAA), intermetatarsal angle (IMA), tibial sesamoid position and frontal plane rotation of the first metatarsal. There were statistically significant differences for each of the assessments between the preoperative and postoperative radiographs (p < .001). There was a mean reduction in the HAA of 23.5° ± 9.6°, in the IMA, 7.0° ± 3.5°, in the tibial sesamoid position, 2.6 ± 1.3, and an improvement in the assessment of first metatarsal pronation (1.4 ± 0.9). The overall complication rate was 18.1%, with 5.7% of the feet requiring reoperation. The minimally invasive procedure employed by the authors demonstrated suitable outcomes in reducing deformity in both the transverse and frontal planes.

Comparison of the clinical and radiological outcomes of Puddu and TomoFix plates for medial opening-wedge high tibial osteotomy: A two-year follow-up of a randomized controlled trial

PurposeOpening-wedge high tibial osteotomy (OWHTO) requires fixation devices for stabilization of the osteotomy gap. The two most commonly used fixation devices are the Puddu and the TomoFix plates. Based on its design, each implant generates a characteristic stability profile. The aim of this randomized controlled trial (RCT) was to investigate the short-term clinical and radiological outcomes of OWHTO using the Puddu and TomoFix plating systems. We hypothesized that the TomoFix plate would achieve superior clinical and radiographic results compared to the Puddu plate. MethodsA total of 60 patients were randomly allocated to undergo OWHTO either using the Puddu plate or the TomoFix plate if conservative treatment failed with symptomatic medial compartment knee osteoarthritis (OA) stage I or II according to Ahlbäck classification, and varus malalignment. All patients underwent clinical and radiological assessment preoperatively, and at 3, 6, 12, and 24months postoperatively. Radiological measurement of the hip-knee-ankle (HKA) angle, and posterior tibial slope (PTS) was performed. Functional assessment was carried out using the Hospital for Special Surgery Knee-Rating Scale (HSS) and the Western Ontario McMaster Universities (WOMAC) Osteoarthritis Index. Patients were also evaluated for intraoperative and postoperative complications throughout the follow-up period. ResultsThe mean angular correction was 9.6±4°, and 10.5±4.8° in the Puddu and TomoFix groups, respectively (p=0.488). The mean PTS change was significantly higher in the Puddu group (3.4±1.1°) compared to the TomoFix group (0.8±0.7°) (p<0.001). There was a statistically significant improvement in the mean HSS and WOMAC in both groups until one year postoperatively. Neither HSS nor WOMAC showed a statistically significant difference between the Puddu and TomoFix groups at any time during the first two postoperative years. The overall complication rate was not significantly different between the Puddu and TomoFix groups. However, the TomoFix group demonstrated higher incidence of symptomatic hardware (23% vs. 3.3%) and removal of metalwork (17% vs. 0%) than the Puddu group (p=0.023 and 0.020, respectively). ConclusionThis RCT suggests that the implant choice for OWHTO has no significant impact on functional outcomes during the first 2years postoperatively. While the Puddu plate was associated with an unintentional increase in the PTS during the surgery, both implants allowed coronal and sagittal plane corrections to be preserved postoperatively. The overall complication rates were similar, but the TomoFix required more material to be removed because it is more cumbersome. However, these results need to be confirmed on a larger scale. Level of evidenceII; randomized controlled trial.

The Predictors of Incidental Durotomy in Patients Undergoing Pedicle Subtraction Osteotomy for the Correction of Adult Spinal Deformity.

Background: Pedicle subtraction osteotomy (PSO) is a powerful tool for sagittal plane correction in patients with rigid adult spinal deformity (ASD); however, it is associated with high intraoperative blood loss and the increased risk of durotomy. The objective of the present study was to identify intraoperative techniques and baseline patient factors capable of predicting intraoperative durotomy. Methods: A tri-institutional database was retrospectively queried for all patients who underwent PSO for ASD. Data on baseline comorbidities, surgical history, surgeon characteristics and intraoperative maneuvers were gathered. PSO aggressiveness was defined as conventional (Schwab 3 PSO) or an extended PSO (Schwab type 4). The primary outcome of the study was the occurrence of durotomy intraoperatively. Univariable analyses were performed with Mann-Whitney U tests, Chi-squared analyses, and Fisher's exact tests. Statistical significance was defined by p < 0.05. Results: One hundred and sixteen patients were identified (mean age 61.9 ± 12.6 yr; 44.8% male), of whom 51 (44.0%) experienced intraoperative durotomy. There were no significant differences in baseline comorbidities between those who did and did not experience durotomy, with the exception that baseline weight and body mass index were higher in patients who did not suffer durotomy. Prior surgery (OR 2.73; 95% CI [1.13, 6.58]; p = 0.03) and, more specifically, prior decompression at the PSO level (OR 4.23; 95% CI [1.92, 9.34]; p < 0.001) was predictive of durotomy. A comparison of surgeon training showed no statistically significant difference in durotomy rate between fellowship and non-fellowship trained surgeons, or between orthopedic surgeons and neurosurgeons. The PSO level, PSO aggressiveness, the presence of stenosis at the PSO level, nor the surgical instrument used predicted the odds of durotomy occurrence. Those experiencing durotomy had similar hospitalization durations, rates of reoperation and rates of nonroutine discharge. Conclusions: In this large multisite series, a history of prior decompression at the PSO level was associated with a four-fold increase in intraoperative durotomy risk. Notably the use of extended (versus) standard PSO, surgical technique, nor baseline patient characteristics predicted durotomy. Durotomies occurred in 44% of patients and may prolong operative times. Additional prospective investigations are merited.

High Tibial Osteotomy in Knee Reconstruction and Joint Preservation.

High tibial osteotomy is a dynamic operation, used as an effective procedure in both joint preservation and knee stability. Applications and indications are expanding, with good results in the treatment of malalignment associated with arthrosis, knee instability, meniscus deficiency or transplants, and/or cartilage restoration. Appropriate patient selection and preoperative planning are critical to achieving good outcomes after surgery. Coronal and sagittal plane corrections made through the proximal tibia can effectively alter joint mechanics creating a more favorable environment for cartilage, meniscus, and ligamentous structures about the knee. Advancing techniques and technologies have allowed for more precise planning and execution of osteotomies.

Maintaining Posterior Tibial Slope and Patellar Height During Medial Opening Wedge High Tibial Osteotomy

Background: Increased posterior tibial slope (PTS) and decreased patellar height (PH) after medial opening wedge high tibial osteotomy (MOWHTO) have been repeatedly reported in the literature. However, this has been disputed in more recent biomechanical studies. Hypothesis: No change in PTS or PH would result after MOWHTO with the freehand technique, regardless of the degree of the coronal plane correction. Study Design: Case series. Methods: A total of 62 patients who underwent MOWHTO between 2018 and 2020 were included. Surgery was performed using a dedicated step-by-step protocol to reduce the risk of unintentional slope changes. All patients were evaluated preoperatively and at a 2-year follow-up with the Knee injury and Osteoarthritis Outcome Score and the University of California, Los Angeles physical activity scale. Pre- and postoperative radiographic lower limb alignment parameters—including hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle, proximal posterior tibial angle (PPTA), joint line convergence angle, and joint line obliquity—were measured on full-length lower limb radiographs. PH measurements assessed on lateral and anteroposterior knee radiographs included the Caton-Deschamps, Insall-Salvati, and Schröter indices. Results: A significant change was observed in the coronal plane alignment, with an increase in the MPTA from 84.38° to 90.39° ( P &lt; .001) and a consequent increase in the HKA from 172.19° to 180.15° ( P &lt; .001). No significant changes were observed in the PTS, as evidenced by a postoperative PPTA of 80.6° versus a preoperative value of 80.4° ( P = .2). No significant changes were detected in the mean PH on all 3 indices used—pre- versus postoperative Caton-Deschamps, Insall-Salvati, and Schröter indices measured 0.95 versus 0.93 ( P = .2), 1.03 versus 1.03 ( P = .5), and 1.56 versus 1.54 ( P = .3), respectively. Conclusion: In this study, MOWHTO did not result in significant changes in the PTS or PH when accurate preoperative planning and precise intraoperative freehand technique were adopted..