scholarly journals Fluoroscopically guided acetabular posterior column screw fixation via an anterior approach

2019 ◽  
Vol 31 (6) ◽  
pp. 503-512 ◽  
Author(s):  
Dietmar Krappinger ◽  
Peter Schwendinger ◽  
Richard A. Lindtner
Keyword(s):  
Ct Scan ◽  
Anterior Approach ◽  
Preoperative Planning ◽  
Screw Fixation ◽  
Posterior Column ◽  
Anterior Column ◽  
Starting Point ◽  
Fluoroscopic Control ◽  
The Mean ◽  
Transverse Fractures

Abstract Objective Safe posterior column screw fixation via an anterior approach under two-dimensional fluoroscopic control. Indications Anterior column with posterior hemitransverse fractures (ACPHF); transverse fractures; two-column fractures and T‑type fractures without relevant residual displacement of the posterior column after reduction of the anterior column and the quadrilateral plate. Contraindication Acetabular fractures requiring direct open reduction via a posterior approach; very narrow osseous corridor in preoperative planning; insufficient intraoperative fluoroscopic visualization of the anatomical landmarks. Surgical technique Preoperative planning of the starting point and screw trajectory using a standard pelvic CT scan and a multiplanar reconstruction tool. Intraoperative fluoroscopically controlled identification of the starting point using the anterior–posterior (ap) view. Advancing the guidewire under fluoroscopic control using the lateral–oblique view. Lag screw fixation of the posterior column with cannulated screws. Postoperative management Partial weight bearing as advised by the surgeon. Postoperative CT scan for the assessment of screw position and quality of reduction of the posterior column. Generally no implant removal. Results In a series of 100 pelvic CT scans, the mean posterior angle of the ideal posterior column screw trajectory was 28.0° (range 11.1–46.2°) to the coronal plane and the mean medial angle was 21.6° (range 8.0–35.0°) to the sagittal plane. The maximum screw length was 106.3 mm (range 82.1–135.0 mm). Twelve patients were included in this study: 10 ACPHF and 2 transverse fractures. The residual maximum displacement of the posterior column fracture component in the postoperative CT scan was 1.4 mm (0–4 mm). There was one intraarticular screw penetration and one perforation of the cortical bone in the transition zone between the posterior column and the sciatic tuber without neurological impairment.

A quantitative anatomic study of plate–screw fixation of the acetabular anterior column through an anterior approach

2009 ◽  
Vol 130 (2) ◽  
pp. 257-262 ◽  
Author(s):  
Wang Xian-quan ◽  
Cai Jin-fang ◽  
Cao Xue-cheng ◽  
Mu Wei-dong ◽  
Zhang Wei ◽  
...  
Keyword(s):  
Anterior Approach ◽  
Screw Fixation ◽  
Anterior Column ◽  
Anatomic Study

Anterior approach to the cervicothoracic junction: proposed indication for manubriotomy based on preoperative computed tomography findings

2011 ◽  
Vol 15 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Asdrubal Falavigna ◽  
Orlando Righesso ◽  
Alisson Roberto Teles
Keyword(s):  
Anterior Approach ◽  
Surgical Planning ◽  
Preoperative Planning ◽  
Preoperative Evaluation ◽  
Length Of Hospital Stay ◽  
Ct Scanning ◽  
Cervicothoracic Junction ◽  
Surgical Time ◽  
The Mean ◽  
Herniated Intervertebral Disc

Object The purpose of this study was to present straightforward preoperative methods to define the need for manubriotomy in the anterior surgical approach to the cervicothoracic junction. Methods Preoperative MR imaging and CT scanning studies were performed in all patients. The CT images with sagittal reconstructions including the manubrium were done to apply the so-called surgeons' view line. This line is parallel to the inferior plateau of the superior healthy vertebrae or the vertebrae above the herniated intervertebral disc, and the decision concerning the need for manubriotomy depends on the correlation between this line and the manubrium. Results Preoperative planning of the need for manubriotomy was correct in all cases. Manubriotomy was never performed in C-7 corpectomy or C7–T1 discectomy cases; nevertheless, manubriotomy was needed in half of the cases when the T-1 corpectomy was the lowest level to be resected (8 cases), and in 4 cases the lowest level to be approached was T-2. The mean surgical time, bleeding volume, postoperative pain intensity, and length of hospital stay were less in the cervicotomy than in the manubriotomy group. Conclusions By using the surgeons' view line and its correlation with the manubrium, the need for manubriotomy can be predicted without compromising decompression and reconstruction. The statistical differences observed in the surgical variables between the manubriotomy and cervicotomy cases justified the use of preoperative evaluation of the need for manubriotomy as an aid to surgical planning and to give the patient and family realistic expectations about the surgery.

The Y-shaped trabecular bone structure in the odontoid process of the axis: a CT scan study in 54 healthy subjects and biomechanical considerations

2019 ◽  
Vol 30 (5) ◽  
pp. 585-592 ◽  
Author(s):  
Nicola Montemurro ◽  
Paolo Perrini ◽  
Vittoriano Mangini ◽  
Massimo Galli ◽  
Andrea Papini
Keyword(s):  
Ct Scan ◽  
Healthy Subjects ◽  
Bone Structure ◽  
Cone Beam Ct ◽  
Odontoid Process ◽  
Trabecular Structure ◽  
Anatomical Entity ◽  
Significant Difference ◽  
Axial Ct ◽  
The Mean

OBJECTIVEOdontoid process fractures are very common in both young and geriatric patients. The axial trabecular architecture of the dens appears to be crucial for physiological and biomechanical function of the C1–2 joint. The aim of this study is to demonstrate the presence of a Y-shaped trabecular structure of the dens on axial CT and to describe its anatomical and biomechanical implications.METHODSFifty-four C2 odontoid processes in healthy subjects were prospectively examined for the presence of a Y-shaped trabecular structure at the odontocentral synchondrosis level with a dental cone beam CT scan. Length, width, and axial area of the odontoid process were measured in all subjects. In addition, measurements of the one-third right anterior area of the Y-shaped structure were taken.RESULTSThe Y-shaped trabecular structure was found in 79.6% of cases. Length and width of the odontoid process were 13.5 ± 0.6 mm and 11.2 ± 0.9 mm, respectively. The mean area of the odontoid process at the odontocentral synchondrosis was 93.5 ± 4.3 mm2, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm2. The mean area of the odontoid process and its length and width were similar in men and women (p > 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm2) compared to people younger than 65 years (93.3 ± 4.4 mm2; p > 0.05).CONCLUSIONSThe authors identified a new anatomical entity, named the Y-shaped trabecular structure of the odontoid process, on axial CT scans. This structure appears to be the result of bone transformation induced by the elevated dynamic loading at the C1–2 level. The presence of the Y-shaped structure provides new insights into biomechanical responses of C2 under physiological loading and traumatic conditions.

Descriptive statistics

2017 ◽  
Author(s):  
Andrew Gelman ◽  
Deborah Nolan
Keyword(s):  
Descriptive Statistics ◽  
Metabolic Rates ◽  
World Record ◽  
Linear Combinations ◽  
Record Times ◽  
Starting Point ◽  
Statistics Course ◽  
Scatter Plots ◽  
Economic Indexes ◽  
The Mean

Descriptive statistics is the typical starting point for a statistics course, and it can be tricky to teach because the material is more difficult than it first appears. The activities in this chapter focus more on the topics of data displays and transformations, rather than the mean, median, and standard deviation, which are covered easily in a textbook and on homework assignments. Specific topics include: distributions and handedness scores; extrapolation of time series and world record times for the mile run; linear combinations and economic indexes; scatter plots and exam scores; and logarithmic transformations and metabolic rates.

Robotic-Assisted Patellofemoral Replacement—Correlation of Preoperative Planning with Intraoperative Implant Position and Early Clinical Experience: A Minimum 2-Year Follow-up

2020 ◽  
Author(s):  
Veenesh Selvaratnam ◽  
Andrew Cattell ◽  
Keith S. Eyres ◽  
Andrew D. Toms ◽  
Jonathan R. P. Phillips ◽  
...  
Keyword(s):  
Functional Outcome ◽  
Preoperative Planning ◽  
Trochlear Dysplasia ◽  
Oxford Knee Score ◽  
Implant Position ◽  
Robotic Assisted ◽  
Implant Positioning ◽  
Flexion Extension ◽  
The Mean

AbstractPatello-femoral arthroplasty (PFA) is successful in a selected group of patients and yields a good functional outcome. Robotic-assisted knee arthroplasty has been shown to provide better implant positioning and alignment. We aim to report our early outcomes and to compare Mako's (Robotic Arm Interactive Orthopaedic System [RIO]) preoperative implant planning position to our intraoperative PFA implant position. Data for this study was prospectively collected for 23 (two bilateral) patients who underwent robotic-assisted PFA between April 2017 and May 2018. All preoperative implant position planning and postoperative actual implant position were recorded. Presence of trochlear dysplasia and functional outcome scores were also collected. There were 17 (two bilateral) female and 6 male patients with a mean age of 66.5 (range: 41–89) years. The mean follow-up period was 30 (range: 24–37) months. Eighteen knees (72%) had evidence of trochlear dysplasia. The anterior trochlear line was on average, 7.71 (range: 3.3–11.3) degrees, internally rotated to the surgical transepicondylar axis and on average 2.9 (range: 0.2–6.5) degrees internally rotated to the posterior condylar line. The preoperative planning range was 4-degree internal to 4-degree external rotation, 4-degree varus to 6-degree valgus, and 7-degree flexion to 3-degree extension. The average difference between preoperative planning and intraoperative implant position was 0.43 degrees for rotation (r = 0.93), 0.99 degrees for varus/valgus (r = 0.29), 1.26 degrees for flexion/extension (r = 0.83), and 0.34 mm for proudness (r = 0.80). Six patients (24%) had a different size component from their preoperative plan (r = 0.98). The mean preoperative Oxford Knee Score (OKS) was 16 and the mean postoperative OKS was 42. No patient had implant-related revision surgery or any radiological evidence of implant loosening at final follow-up. Our early results of robotic PFA are promising. Preoperative Mako planning correlates closely with intraoperative implant positioning. Longer follow-up is needed to assess long-term patient outcomes and implant survivorship.

Distance of the Posterior Interosseous Nerve From the Bicipital (Radial) Tuberosity at Varying Positions of Forearm Rotation: A Magnetic Resonance Imaging Study With Clinical Implications

2021 ◽  
Vol 49 (5) ◽  
pp. 1152-1159
Author(s):  
Tyler A. Luthringer ◽  
David A. Bloom ◽  
David S. Klein ◽  
Samuel L. Baron ◽  
Erin F. Alaia ◽  
...  
Keyword(s):  
Anterior Approach ◽  
Single Incision ◽  
Biceps Tendon ◽  
Tendon Repair ◽  
Resonance Imaging ◽  
Forearm Rotation ◽  
Mri Scans ◽  
Biceps Tendon Repair ◽  
The Mean ◽  
Bicipital Tuberosity

Background: The proximity of the posterior interosseous nerve (PIN) to the bicipital tuberosity is clinically important in the increasingly popular anterior single-incision technique for distal biceps tendon repair. Maximal forearm supination is recommended during tendon reinsertion from the anterior approach to ensure the maximum protective distance of the PIN from the bicipital tuberosity. Purpose: To compare the location of the PIN on magnetic resonance imaging (MRI) relative to bicortical drill pin instrumentation for suspensory button fixation via the anterior single-incision approach in varying positions of forearm rotation. Study Design: Descriptive laboratory study. Methods: Axial, non–fat suppressed, T1-weighted MRI scans of the elbow were obtained in positions of maximal supination, neutral, and maximal pronation in 13 skeletally mature individuals. Distances were measured from the PIN to (1) the simulated path of an entering guidewire (GWE-PIN) and (2) the cortical starting point of the guidewire on the bicipital tuberosity (CSP-PIN) achievable from the single-incision approach. To radiographically define the location of the nerve relative to constant landmarks, measurements were also made from the PIN to (3) the prominent-most point on the bicipital tuberosity (BTP-PIN) and (4) a perpendicular plane trajectory from the bicipital tuberosity exiting the opposing radial cortex (PPT-PIN). All measurements were subsequently compared between positions of pronation, neutral, and supination. In supination only, BTP-PIN and PPT-PIN measurements were made and compared at 3 sequential axial levels to evaluate the longitudinal course of the nerve relative to the bicipital tuberosity. Results: Of the 13 study participants, mean age was 38.77 years, and mean body mass index was 25.58. Five participants were female, and 5 left and 8 right elbow MRI scans were reviewed. The GWE-PIN was significantly greater in supination (mean ± SD, 16.01 ± 2.9 mm) compared with pronation (13.66 ± 2.5 mm) ( P < .005). The mean CSP-PIN was significantly greater in supination (16.20 ± 2.8 mm) compared with pronation (14.18 ± 2.4 mm) ( P < .013).The mean PPT-PIN was significantly greater in supination (9.00 ± 3.0 mm) compared with both pronation (1.96 ± 1.2 mm; P < .001) and neutral (4.73 ± 2.6 mm; P < .001). The mean BTP-PIN was 20.54 ± 3.0, 20.81 ± 2.7, and 20.35 ± 2.9 mm in pronation, neutral, and supination, respectively, which did not significantly differ between positions. In supination, the proximal, midportion, and distal measurements of BTP-PIN did not significantly differ. The proximal PPT-PIN distance (9.08 ± 2.9 mm) was significantly greater than midportion PPT-PIN (5.85 ± 2.4 mm; P < .001) and distal BTP-PIN (2.27 ± 1.8 mm; P < .001). Conclusion: This MRI study supports existing evidence that supination protects the PIN from the entering guidewire instrumentation during anterior, single-incision biceps tendon repair using cortical button fixation. The distances between the entering guidewire trajectory and PIN show that guidewire-inflicted injury to the nerve is unlikely during the anterior single-incision approach. Clinical Relevance: When a safe technique is used, PIN injuries during anterior repair are likely the result of aberrant retractor placement, and we recommend against the use of retractors deep to the radial neck. Guidewire placement as close as possible to the anatomic footprint of the biceps tendon is safe from the anterior approach. MRI evaluation confirms that ulnar and proximal guidewire trajectory is the safest technique when using single-incision bicortical suspensory button fixation.

scholarly journals Promising medium-term results of anterior approach with an anatomical short stem in primary hip arthroplasty

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fabrizio Rivera ◽  
Alessandro Bardelli ◽  
Andrea Giolitti
Keyword(s):  
Operating Room ◽  
Anterior Approach ◽  
Direct Anterior Approach ◽  
Short Stem ◽  
Medium Term ◽  
Operating Room Table ◽  
Sf 36 ◽  
Standard Operating ◽  
The Mean

Abstract Background In the last decade, the increase in the use of the direct anterior approach to the hip has contributed to the diffusion of the use of short stems in orthopedic surgery. The aim of the study is to verify the medium-term clinical and radiographic results of a cementless anatomic short stem in the anterior approach to the hip. We also want to verify whether the use of the standard operating room table or the leg positioner can affect the incidence of pre- and postoperative complications. Materials and methods All total hip arthroplasty patients with a 1-year minimum follow-up who were operated using the MiniMAX stem between January 2010 and December 2019 were included in this study. Clinical evaluation included the Harris Hip Score (HHS), Western Ontario and McMaster Universities Hip Outcome Assessment (WOMAC) Score, and Short Form-36 (SF-36) questionnaires. Bone resorption and remodeling, radiolucency, osteolysis, and cortical hypertrophy were analyzed in the postoperative radiograph and were related to the final follow-up radiographic results. Complications due to the use of the standard operating room table or the leg positioner were evaluated. Results A total of 227 patients (238 hips) were included in the study. Average age at time of surgery was 62 years (range 38–77 years). Mean follow-up time was 67.7 months (range 12–120 months). Kaplan–Meier survivorship analysis after 10 years revealed 98.2% survival rate with revision for loosening as endpoint. The mean preoperative and postoperative HHS were 38.35 and 94.2, respectively. The mean preoperative and postoperative WOMAC Scores were 82.4 and 16.8, respectively. SF-36 physical and mental scores averaged 36.8 and 42.4, respectively, before surgery and 72.4 and 76.2, respectively, at final follow-up. The radiographic change around the stem showed bone hypertrophy in 55 cases (23%) at zone 3. In total, 183 surgeries were performed via the direct anterior approach (DAA) on a standard operating room table, and 44 surgeries were performed on the AMIS mobile leg positioner. Comparison between the two patient groups did not reveal significant differences. Conclusion In conclusion, a short, anatomic, cementless femoral stem provided stable metaphyseal fixation in younger patients. Our clinical and radiographic results support the use of this short stem in the direct anterior approach. Level of evidence IV.

Transverse Lag Screw Fixation in Midline Mandibulotomy

2000 ◽  
Vol 109 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Joseph M. Serletti ◽  
John U. Coniglio ◽  
Salvatore J. Pacella ◽  
John D. Norante
Keyword(s):  
Reliable Method ◽  
Screw Fixation ◽  
Postoperative Radiotherapy ◽  
Major Complication ◽  
Recurrent Tumor ◽  
Minor Complication ◽  
Anterior Cortex ◽  
Lag Screw ◽  
The Mean

Vertical midline mandibulotomy has provided a relatively simple and efficient means of obtaining access to intraoral tumors that are too large or too posterior to be removed transorally. Midline mandibulotomy has had the advantage of nerve and muscle preservation and places the osteotomy outside the typical field of radiotherapy, in contrast to lateral and paramedian osteotomies. Plate and screw fixation has been the usual means of osteosynthesis for these mandibulotomies; however, plate contouring over the symphyseal surface has been a time-consuming process. Unless the plate was contoured exactly, mandibular malalignment and malocclusion in dentulous patients has occurred. Use of parallel transverse lag screws has become a popular method of osteosynthesis for parasymphyseal fractures, and we have extended their use for mandibulotomy fixation. This paper reports our clinical experience with transverse lag screw fixation of midline mandibulotomies in 9 patients from 1994 to 1997. There were 7 men and 2 women with a mean age of 56 (range 35 to 71 years). The pathological diagnosis in all patients was squamous cell carcinoma; 8 cases were primary, and 1 patient presented with recurrent tumor. No tumors involved the mandibular periosteum. One patient had had previous radiotherapy, and 3 patients underwent postoperative radiotherapy. The mean follow-up has been 17 months (range 9 to 27). There was 1 minor complication and 1 major complication related to our technique. The major complication was a delayed nonunion of the mandibulotomy. This occurred because the 2 parallel screws were placed too close to one another, and this placement resulted in a delayed sagittal fracture of the anterior cortex and subsequent nonunion. Transverse lag screw fixation has not affected occlusion in our dentulous patients. Speech and diet were normal in the majority of our patients. Transverse lag screw fixation of the midline mandibulotomy has been a relatively safe, rapid, and reliable method for tumor access and postextirpation mandibular stabilization and has significant advantages over other current methods of mandibulotomy and fixation.

Sign in / Sign up

Export Citation Format

Share Document