Lateral Rim Research Articles

Patients With Dysplasia Achieve Similar Outcomes and Survivorship to Nondysplastic Patients 10 Years After Hip Arthroscopy for Femoroacetabular Impingement

To determine the long-term outcomes of hip arthroscopy (HA) for femoroacetabular impingement (FAI) in the presence of concomitant lateral rim dysplasia compared with a matched control group. Patients undergoing HA between January 2009 and October 2013 with minimum 10-year follow-up were reviewed. The inclusion criteria consisted of patients undergoing HA for FAI with evidence of lateral rim dysplasia (lateral-center edge angle [LCEA] < 25°). Patients with lateral rim dysplasia were matched to patients with an LCEA greater than 30° based on sex, Tönnis grade, and age. Outcomes included survival (avoidance of total hip replacement [THR]), repeated HA, and patient-reported outcomes (PROs). Survivorship was assessed using a Kaplan-Meier curve and log rank test, whereas revision rates between groups were assessed using χ2 analysis. Between- and within-group analyses of PROs were conducted using the Mann-Whitney U test and Wilcoxon signed rank test, respectively. The proportion of cases achieving the patient acceptable symptom state was compared between groups using χ2 analysis. This study comprised 46 dysplasia cases and 90 control cases. There was no statistically significant difference between groups in baseline metrics apart from the LCEA (P < .001), Sharp angle (P < .001), and Tönnis angle (P < .001). By 10 years postoperatively, 9% of dysplasia cases and 4% of control cases underwent conversion to THR. There was no statistically significant difference between groups in survival or revision rates. Both groups reported improvements in PROs, and there was no difference between PRO scores at either time point. Excluding cases that underwent THR, 84% and 83% of dysplasia and control cases, respectively, achieved the patient acceptable symptom state. HA for symptomatic FAI is a successful treatment in cases in which dysplasia is present. Low complication rates, comparable outcomes to cases without lateral rim dysplasia, and a high survivorship rate of 91% at minimum 10-year follow-up are observed. Increasing Tönnis angle preoperatively may increase the risk of THR conversion. Level IV, retrospective cohort study.

A newly designed anatomical plate for the therapy of posterolateral tibial plateau fracture via a supra-fibular-head approach: a retrospective study.

The posterolateral tibial plateau fracture is a special type of intra-articular fracture, for which there is no simple, safe, and effective standardized procedure. In this paper, we evaluate the clinical efficacy and the advantages of the treatment of posterolateral tibial plateau fracture by using our designed proximal lateral tibial rim plate for the posterolateral condyle of the tibial plateau via the space above the fibula head. Thirty-eight patients with posterolateral tibial plateau fractures from June 2018 to June 2021 were retrospectively analyzed. CT scans were used to classify the degree of injury in the included patients. All of them were fixed with reduction using an approach above the fibula head combined with a homemade anatomical plate. The regular postoperative review was performed to instruct functional knee exercises. Postoperative complications were observed and follow-up visits were performed to assess the functional outcome. A total of 38 patients with posterolateral tibial plateau fractures, 13 males and 25 females were included in the study. All patients were followed up for 13-26months, with a mean of 15.3months. There were no postoperative complications such as numbness of the limb, knee joint instability, etc. X-ray review showed that the fractures were all healed, and the healing time was 10-16weeks, with an average of 12.1weeks; none of the internal fixation loosening and loss of articular surface occurred during the follow-up period. At the last follow-up, according to the HSS knee function score criteria, the scores were 79-98, with an average of 91.3. The HSS score presented excellent in 34 cases (89%) and good in 4 cases (11%). The Rasmussen score was graded as excellent in 29 cases (76%) and good in 9 cases (24%). In conclusion, The treatment of posterolateral tibial plateau fractures by an approach above the fibula head has the advantages of simplicity and safety, small trauma, and no risk of vascular and nerve injuries, and the anatomical proximal lateral tibial rim plate can play a direct and effective supporting role for the bone fragments of the posterolateral condyle, and the combination of both of them has obvious advantages in the treatment of posterolateral condylar fracture of the tibial plateau, and it is a method worth borrowing and popularizing.

Statocyst Ultrastructure in the Norwegian Lobster (Nephrops norvegicus).

Statocyst anatomy and fine morphology in Norwegian lobster (Nephrops norvegicus) are studied for the first time using scanning and transmission electron microscopy. N. norvegicus exhibits sensory setae projecting from the statocyst inner cavity floor into a mass of sand granules (statoconia) embedded in a gelatinous substance. The setae are distributed in four areas: a curved field made up of an inner single row and an outer double row that run on a circle around the medial and lateral rim of the central depression, a small setal field in the posterior part, a large setal field, opposite to the small field, and a short row, running internally and lying parallel to the inner single row, next to the small setal field. A study of the fine morphology of the statocyst sensory setae shows that the structure of the setae in the different areas is similar, with a bulb (the proximal portion of the sensillum), a setal shaft, a tooth (the smooth portion of the bulb), a fulcrum (a transverse fold), and filamentous hairs. The hair cells are firmly implanted within the cuticular layer. Although the type of innervation of the statocyst was not determined in the present study, the close taxonomic position of the lobster to that of the crayfish and crab would suggest that the setae in N. norvegicus are pure mechanoreceptors rather than sensory cells.

Lateral rim variable angle locked plating versus tension band wiring of simple and complex patella fractures: a biomechanical study.

Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.

LATERAL RIM VARIABLE ANGLE LOCKED PLATING VERSUS TENSION BAND WIRING OF SIMPLE AND COMPLEX PATELLA FRACTURES: A BIOMECHANICAL STUDY

Treatment of both simple and complex patella fractures is a challenging clinical problem. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures.Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or a lateral rim variable angle locking plate.Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full knee extension. Interfragmentary movements were captured via motion tracking.For both fracture types, the longitudinal and shear articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p&lt;0.01.Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.

Keyhole concept applied to Endoscopic Transorbital Approach with and without Lateral Rim Osteotomy: Clinical Experience and Anatomical Reappraisal

Keyhole concept applied to Endoscopic Transorbital Approach with and without Lateral Rim Osteotomy: Clinical Experience and Anatomical Reappraisal

Osteology of the axial skeleton of Aucasaurus garridoi: phylogenetic and paleobiological inferences.

Aucasaurus garridoi is an abelisaurid theropod from the Anacleto Formation (lower Campanian, Upper Cretaceous) of Patagonia, Argentina. The holotype of Aucasaurus garridoi includes cranial material, axial elements, and almost complete fore- and hind limbs. Here we present a detailed description of the axial skeleton of this taxon, along with some paleobiological and phylogenetic inferences. The presacral elements are somewhat fragmentary, although these show features shared with other abelisaurids. The caudal series, to date the most complete among brachyrostran abelisaurids, shows several autapomorphic features including the presence of pneumatic recesses on the dorsal surface of the anterior caudal neural arches, a tubercle lateral to the prezygapophysis of mid caudal vertebrae, a marked protuberance on the lateral rim of the transverse process of the caudal vertebrae, and the presence of a small ligamentous scar near the anterior edge of the dorsal surface in the anteriormost caudal transverse process. The detailed study of the axial skeleton of Aucasaurus garridoi has also allowed us to identify characters that could be useful for future studies attempting to resolve the internal phylogenetic relationships of Abelisauridae. Computed tomography scans of some caudal vertebrae show pneumatic traits in neural arches and centra, and thus the first reported case for an abelisaurid taxon. Moreover, some osteological correlates of soft tissues present in Aucasaurus and other abelisaurids, especially derived brachyrostrans, underscore a previously proposed increase in axial rigidity within Abelisauridae.

Clinical anatomy of the spina musculi recti lateralis: A frequently overlooked variation of the greater wing of the sphenoid

BackgroundThe spina musculi recti lateralis (SMRL) is often visible along the lateral rim of the superior orbital fissure (SOF). Aim of this study is to characterize SMRL morphology and topography relative to known bony landmarks. MethodsOrbits from 291 adult dry skulls and from 60 CT scans were analyzed to measure the distance between the SMRL and the SOF or the inferior orbital fissures (IOF) as well as its height, width and orientation. Processes other than SMRLs were also recorded. Fetal skulls were observed for comparison with adult samples. ResultsForty-one per cent of orbits on dry skulls and 43.3% by CT showed an SMRL. Additional 32.9% of orbits on dry skulls had processes with a different shape. On average, SMRL were orientated almost along the transverse plane and showed implant bases as wide as 141.9° or as narrow as 36.8°. SMRLs were close to the infero-posterior angle of the orbital plate of the sphenoid, 1.21 ± 0.84 mm in front of the SOF, 5.8 ± 1.9 mm above the IOF and 12 ± 2.3 mm from the anterior end of the SOF. They were 1.58 ± 0.64 mm high and did not show any age or sex-related prevalence. By CT, the SMRL appeared as the insertion site for the lateral rectus, tendinous ring and, sometimes, inferior rectus. ConclusionsThe SMRL is a process of the sphenoidal orbital plate rather than of the SOF. It is also a reliable landmark for the insertion of the tendinous ring and lateral rectus. Orbital surgeons should be aware of this common variant of the orbital apex.

Twenty Year review for Craniofacial Distraction in syndromic craniosynostosis

Introduction: Craniosynostosis are cranial deformities resulting from the early closure of one or more sutures. Concomitant facial changes usually result from the involvement of multiple sutures, which may lead to restriction of cranial growth and brain expansion, ocular compression, and breathing difficulties. The distraction osteogenesis (DO)for frontofacial or posterior advancement have increased the safety of the procedure. The aim of this study was a critical evaluation of the use of DO in the surgical treatment of syndromic craniosynostoses, based on the experience of a single craniofacial team.&#x0D; Methods: Retrospective review of third six patients operated from 2003 to 2022 by the same craniofacial team.&#x0D; Results: 19 boys and 17 girls were operated, all with rigid distractors. Twenty-nine of them underwent monobloc frontofacial advancement. In seven patient a Le-Fort III/subcranial advancement was performed. A posterior craniofacial advancement was performed in 5. In 11 a fronto-orbital advancement was done in the first year of life. The mean age was 6.0 years (range, 6 months to 13 years). All patients presented with some degree of exorbitism, upper airway obstruction and signs of intracranial hypertension. Cerebrospinal fluid leakage was the most frequent complication (9 cases), pterygomaxillary disjunction was revised in 8, lateral rim orbital fracture in 3 cases, and 3 complication related to the device.&#x0D; Conclusions: The evolution of surgical techniques allowed DO with rigid distractors to be an important tool for treating the craniofacial issues related to syndromic craniosynostoses. The multidisciplinary team's learning curve is critical to reducing complications associated with osteogenic distraction.

The anterior superior iliac spine is a reliable novel landmark for preemptive periacetabular analgesia in hip arthroscopy.

Appropriate post-operative (post-op) pain control has been shown to reduce length of stay and facilitate day case surgery. Periacetabular injection of bupivacaine is effective in pain reduction after hip arthroscopy. This study aims to evaluate the anterior superior iliac spine (ASIS) as an anatomical landmark to facilitate needle insertion prior to fluoroscopy. The meeting point derived from a vertical line one fingerbreadth distal to the ASIS and a longitudinal line from the greater trochanter (GT) was used as a landmark in 30 consecutive hip arthroscopy patients for periacetabular analgesia. The distance between the tip of the needle and the acetabular roof was measured via fluoroscopy. Needle location was corrected if needed, followed by periacetabular bupivacaine injection (at anterior, lateral and posterior joint aspects). Post-op pain was measured using the Visual Analog Scale (VAS) 4-6 h post-op and at discharge. The ASIS and GT were identified and used for periacetabular analgesia landmarks in all cases. Results revealed that 93.3% of needle entries fell within 10 mm of the lateral acetabular rim and only one case had fallen distal to it. The post-op mean VAS score was 1.03 (range 0-6, standard error - 0.30, median = 0). At hospital discharge, 90% (27/30 of patients) reported VAS score ≤ 5. Twenty-six of the 30 patients were discharged on the same day as the operation (remaining four patients stayed due to accommodation/traveling issues). The ASIS and GT can be used as an anatomical landmark for periacetabular analgesia in hip arthroscopy with reproducible needle location, significant analgesic effect and minimal radiation.

Challenges in the Head and Neck Department in the Diagnosis and Surgical Treatment of Patients Presenting to a Single Tertiary Hospital of Somalia With Extreme War Injuries.

In this study, the authors aimed to share their experience with 46 patients who were wounded due to terrorism and war in Somalia. The authors also evaluated the etiological diversity of terror-related and war-related injuries. The study included 46 patients treated at the 150-bed Turkey-Somalia Tertiary Hospital between 2019 and 2021. The authors reviewed medical records including data regarding age, sex, trauma etiology, and type of fracture and trauma. For all patients, surgical technique and plate and screw applications were recorded. The authors also assessed complications and outcomes for the patients. The study included 5 women (10.9%) and 41 men (89.1%). The mean age was 30.36 years. It was found that 2 patients (4.35%) presented to the emergency department with stab injuries, 33 patients with blast injuries from improvised explosive devices (71.73%), and 11 patients with firearm injuries. There were 31 patients with maxillary and mandibular fractures, 17 of which had both maxillary and mandibular fractures. There were 14 patients with maxillary fracture alone, including 3 patients with tripod fracture and 7 patients with inferior and lateral rim fracture. There was a mandibular fracture in 17 patients, including 5 patients with parasymphysis fracture, 7 patients with ramus fracture, and 5 patients with multifocal comminuted fracture. It is a challenging process to treat terror-related injuries in our tertiary hospital in Somalia, where all resources are imported from foreign countries. In such settings, authorities should make protective equipment obligatory to prevent civil and military casualties. Trauma hospitals and experienced trauma surgeons should be available.

High Survivorship and Comparable Patient-Reported Outcomes at a Minimum 5 Years After Hip Arthroscopic Surgery in Patients With Femoroacetabular Impingement, With and Without Lateral Rim Dysplasia

Background: Femoroacetabular impingement (FAI) in patients with dysplasia presents a unique challenge to surgeons. Short-term outcomes are conflicting, while longer term follow-up data are only emerging. Purpose: To quantify midterm (minimum 5-year follow-up) outcomes after the arthroscopic correction of FAI in the presence of lateral rim dysplasia compared with a matched control group with FAI with normal acetabular coverage. Study Design: Cohort study; Level of evidence, 3. Methods: Prospective outcome data, collected in a consecutive series of patients undergoing arthroscopic FAI correction with lateral rim dysplasia (lateral center-edge angle [LCEA] of 13°-25°), were reviewed (N = 75 cases). An age- and sex-matched control group of 120 cases was also formed (LCEA >25°). Survivorship was defined as the avoidance of total hip replacement and assessed using a Kaplan-Meier curve with the log-rank test. Survival rates and patient-reported outcome measure (PROM) scores (modified Harris Hip Score [mHHS], University of California, Los Angeles [UCLA], 36-Item Short Form Health Survey [SF-36], and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] preoperatively and at 5 years postoperatively) were compared between the groups. The proportion of patients across groups achieving the minimal clinically important difference (MCID) was compared for each PROM. The dysplasia group was also analyzed independently to identify any factors that may indicate a less favorable outcome using regression analysis. The group was divided into 2 subgroups: borderline dysplasia (LCEA of 20°-25°) and severe dysplasia (LCEA <20°). Results: The survival rate in the dysplasia group was 97%. There was no statistical difference with respect to survival rates or any PROM scores (P > .05 for all) between the groups. There were similar rates of achieving the MCID between the groups for the mHHS, UCLA, and WOMAC. The FAI control group had a higher rate of achieving the MCID for the SF-36 (P = .012; effect size = 0.274 [small]). Subgroup analysis indicated a lower survival rate (78% vs 100%, respectively; P < .001) in female cases in the dysplasia group (n = 9) compared with male cases in the dysplasia group (n = 66). The UCLA score in female cases in the dysplasia group at 5 years was statistically lower compared with that in male cases in the dysplasia group (6 vs 10, respectively; P = .003; effect size = 0.378 [medium]), but no other outcome revealed any differences between the sexes. There were also no variables identified on regression analysis that accurately predicted a poorer outcome in the dysplasia group. When stratified by severity, there was no difference in survivorship or outcomes between those with severe dysplasia (LCEA <20°; n = 11) and those with borderline dysplasia (LCEA of 20°-25°; n = 64). Conclusion: An arthroscopic intervention was a successful treatment option for FAI in the presence of lateral rim dysplasia at midterm follow-up. Irrespective of the severity of dysplasia, patients can expect similar improvements to those in patients with normal femoral head coverage.

Effect of Rim-Off Deep Lateral Orbital Decompression on Interpalpebral Fissure Shape.

The purpose of this study is to compare the palpebral fissure shape after rim-off deep lateral decompression with and without restoration of the lateral orbital rim. Retrospective cross-sectional quantitative analysis of the palpebral fissure images of 17 patients (25 eyes) who underwent rim-off deep lateral orbital decompression without repositioning of the rim (G1) and of 20 patients (34 eyes) operated with rim restoration. Quantification of palpebral fissure images included MRD 1 and MRD 2 , two lateral mid-pupil lid margin (MPD) distances, the width of the palpebral fissure, and the height and shape of the lateral canthus. Proptosis reduction did not differ significantly between G1 and G2. In both groups, decompression reduced the mean values of the MRD 1 and MRD 2 , the lateral height of the upper eyelid, and the height and angle of the lateral canthus. The palpebral fissure width and lateral height of the lateral lower eyelid were not affected. There was no significant difference between the mean changes of G1 and G2. Multivariate analysis showed that the lateral canthus decrease was correlated with changes in MRD 1 and MRD 2 . Small changes in palpebral fissure shape after deep lateral decompression are not dependent on the presence or absence of the lateral rim.

Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine

IntroductionIn spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities.Materials and methodsPosterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded.ResultsThoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5%) and 28 screws (1.6%), while the midline of the vertebral body was crossed in 8 screws (0.5%). Furthermore, 11 screws each (0.6%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1% of patients, whereas neurological deterioration occurred in 8.9% of cases with neurological follow-up.ConclusionsCombination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.

Orbital Aging: A Computed Tomography-Based Study of 240 Orbits.

Previous studies have attempted to explain age-related changes to the orbit in isolation, often producing conflicting results. The authors used highly accurate imaging software to analyze computed tomographic scans to characterize changes related to age objectively. In this case-control study, patients seen in an ear, nose, and throat clinic were screened for study entry. Male and female participants were divided into two age groups (20 to 30 years and 60 to 75 years). Primary outcomes included measurement of bony orbital dimensions, volume of soft tissues (muscle and fat volume), and anterior globe position. Three-dimensional reconstructions were created of each orbit allowing these measurements. The generalized estimating equation was used so that both orbits from each patient could be included without any bias. The final sample included 240 orbits from 120 patients. There were 30 patients in each age group. Among female participants, the bony orbital volume ( p < 0.05), fat volume ( p < 0.01), and central width ( p < 0.001) of the bony orbit increased with age. The anterior globe position was significantly greater in older female participants ( p < 0.01). For male participants, the fat volume ( p < 0.0001) and central height ( p < 0.03) increased with age; the lateral rim moved posteriorly with age ( p < 0.007). The anterior globe position was not different between the age groups in male participants ( p = 0.56). The female bony orbit expands with age and is associated with a more anterior position of the globe; the male bony orbital volume remains the same and the lateral rim moves posteriorly.

ACETABULAR DYSPLASIA AND DEVELOPMENT OF HIP OSTEOARTHRITIS WITHIN 10 YEARS; A NATIONWIDE PROSPECTIVE COHORT STUDY (CHECK)

Purpose: Attempts to relate acetabular dysplasia (AD) to the development of hip osteoarthritis (OA) have yielded conflicting results. Previous results from the Cohort Hip and Cohort Knee (CHECK) study showed an up to 6-fold increased risk of developing hip osteoarthritis within 5 years when AD was present at both the anterior and lateral rim. We now determined the relationship between anterior and lateral AD at baseline and the risk of developing radiographic hip OA within 10 years of follow-up, using data from the prospective CHECK cohort.

Effect of orbital wall resection areas in the treatment of patients with endocrine orbitopathy

In patients treated by orbital wall decompression for endocrine orbitopathy (EO) there is limited evidence on the effect of orbital wall resections. Thus, the aim of this study was to evaluate the effect of one, two, and three-wall resections on orbital parameters to determine if any such correlations exist. Preoperative and postoperative data from all patients at a tertiary care centre who underwent decompression surgery from 2010 - 2020 were digitally analysed. The effect of the number and area of resected walls on orbital area, orbital volume, and Hertel value, and the effect of lateral rim advancement (LARA) were determined. A total of 131 orbital areas showed an increase from a mean (SD) preoperative area of 42.0 (4.6) cm2 to 47.3 (6.1) cm2 postoperatively (p<0.001). In total, the mean (SD) area of osseous wall removed in all patients was 6.2 (1.7) cm2 at the lateral orbit (n = 129), 6.7 (2.3) cm2 at the orbital floor (n = 123), and 5.8 (1.8) cm2 at the medial orbital wall (n =30). The mean (SD) orbital volume increased by 6.0 (3.0) cm3 after decompression. There was also a significant reduction in exophthalmos of 7.3 (3.2) mm (from 25.2 (3.9) to 17.9 (3.5), p<0.001). LARA was performed in 50 patients. Changes in volume and area, and reduction in exophthalmos were not significantly different with or without LARA. The postoperative effects of orbital wall resection are predictable and exhibit a relation with six units of change. Two-wall resection is the most common intervention.

Knee Avulsion Injuries: What can I Get From a CT?

Acute bone and soft-tissue injuries to the knee are commonly seen in emergency departments as well as in the outpatient clinic. Most commonly, these injuries result from a direct blow, a fall, or a twisting injury. Prompt and accurate diagnosis relies heavily on imaging and is mandatory to facilitate adequate management and prevent potential complications [1]. Radiographs are usually the initial imaging modality in the evaluation of the acutely injured knee but have a low yield. Computed Tomography (CT) may be performed as the next imaging study for the evaluation of suspected radiographically occult fractures. In patients with radiographic diagnosis of knee fracture, CT is frequently performed for further classification and characterization of the fracture severity and for prediction or diagnosis of associated meniscal and ligamentous injuries [12]. The knee has numerous tendinous, ligamentous, and meniscal attachments, which make it particularly vulnerable to avulsion injuries after trauma. These include avulsions of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), Segond (small bony avulsion of the anterolateral ligament at the lateral tibial rim that indicates a ACL tear) and reverse Segond (small medial tibial avulsion fracture that indicates a PCL tear) fractures, fibular head avulsion fracture, arcuate complex avulsion, fracture avulsions of the medial collateral ligament, iliotibial band avulsion, avulsions of the semimembranosus, and quadriceps tendons, and patellar sleeve fractures. In the setting of acute twisting trauma to the knee, CT scan has high sensitivity and specificity in detecting bony avulsion fractures and a high negative predictive value for excluding ligamentous injuries (e.g.: ACL avulsion fracture) [3] (Figure 1). Radiologists should recognize the pattern of these injuries and their underlying mechanism to understand the substantial damage that it frequently represents. This presentation will outline the imaging appearances of common knee avulsion fractures. Specific examples will be used to highlight clinical relevance and learning points.

Long-term Minimum 15-Year Follow-up After Lateral Discoid Meniscus Rim Preservation Surgery in Children and Adolescents.

Discoid meniscus is a congenital variant typically affecting the lateral meniscus of the knee. Historically, surgical intervention when symptomatic consisted of total meniscectomy; however, after degenerative changes were observed, current treatments now focus on rim preservation with arthroscopic saucerization and meniscal repair for instability, when indicated. The purpose of our study was to examine long-term patient-reported outcomes of lateral discoid meniscus (LDM) treated with meniscal-preserving techniques. Ninety-eight patients treated arthroscopically for LDM at a single institution at a minimum of 15 years ago were retrospectively identified and contacted by mailers and telephone to participate. Subjective functional outcomes and patient satisfaction data were collected using a questionnaire that included the validated International Knee Documentation Committee Subjective Knee Evaluation Form, Lysholm Score, Marx Activity Rating Scale, Tegner Activity Score, and Western Ontario and McMaster University Osteoarthritis Index Osteoarthritis Index. Patient and surgical characteristics and patient-reported outcomes were summarized by mean and SD, median and interquartile range (interquartile range), or frequency and percent, as appropriate. Of the 46 patients contacted (response rate of 46/98 eligible), 25 (54%) completed the questionnaires. The mean (±SD) age at initial surgery was 10.8 (±3.4) and 30.3 (±3.7) years at final follow-up. The mean (±SD) follow-up time from initial surgery was 19.5 (±2.8) years (range, 16 to 27). Patient-reported outcomes included: International Knee Documentation Committee 77.4±17.2, Lysholm 78.6±21, Western Ontario and McMaster University Osteoarthritis Index 7.6±11.3, Tegner Activity 7 (of 10), and Marx Activity Rating Scale 8 (of 10). Eleven (44%) cases underwent subsequent LDM-related surgery on the ipsilateral knee(s). There were no cases of total knee replacement. Overall, patient-reported outcomes were favorable at a minimum of 15-year follow-up after rim-preserving saucerization of LDM. While two thirds of patients were satisfied with their surgical outcomes, nearly half of patients underwent revision saucerization with or without meniscal repair. Subsequent long-term follow-up studies with objective outcome measures are important to further elucidate the natural history of LDM and understand how rim-preserving procedures may prevent the development of degenerative processes. Level IV-case series, prognostic study.

GROWTH OF THE PEDIATRIC KNEE MENISCUS: A CADAVERIC STUDY

Background:The menisci of the knee play a critical role in maintaining structural integrity, as well as in load bearing and shock absorption. In adolescent patients, meniscal tear is a very common sports injury, and is frequently associated with concomitant traumatic injuries including tibial eminence fracture or ACL tear. The incidence of pediatric meniscal tears is increasing, and anatomic studies to guide repair, saucerization and transplantation do not exist.Hypothesis/Purpose:This study’s purpose was to evaluate meniscus dimensions in the developing meniscus and provide anatomic parameters for repair, saucerization, resection, transplantation.Methods:From images of 29 dissected cadaveric knee specimens between 1 month and 132 months of age obtained on a copy stand (14 left knee, 15 right knee), we made direct length measurements from the inner to outer meniscus rim at 45 degree intervals (12, 1:30/10:30, 3:00/9:00, 4:30/7:30 o’clock, 6 o’clock) using Autodesk Fusion 360 software (Figure 1.1). We also measured width between the outer medial and lateral meniscus rims, as well as CT measurements of coronal and sagittal width of the tibial plateau using OsiriX DICOM software. Generalized linear models were used to evaluate the associations of meniscal length measurements with age, tibial width, and meniscal width measurements. All statistical analyses were completed with a two-sided level of significance of 0.05.Results:All radial length measurements were predicted to increase significantly with age (p < 0.01), as coronal tibial width increases (p < 0.05), and as lateral-medial meniscal width increases (p < 0.001) (Figure 1.2). Other than the lateral 3 o’clock measurement (p = 0.119), all radial measurements were predicted to increase significantly as sagittal tibial width increases (p < 0.05). The posterior zones of the medial meniscus (6:00, 4:30/7:30) were found to increase in radial length at a faster rate than the anterior zones. The anterior zones of the medial meniscus (12:00, 1:30/10:30) had the slowest rate of growth.Discussion/Conclusion:Meniscus radial length is related to age, tibial plateau width, and lateral-medial meniscus width. Radial dimensions from normal lateral menisci may allow the surgeon to obtain ideal size of resection, saucerization of discoid menisci. The growth of medial meniscus posterior zones is greater than the anterior zones. This may be attributed to increased posterior region load bearing which increases with ambulation in the developing child. Improved anatomic understanding may help surgeons plan for discoid resection/saucerization/repair, and also support appropriate selection of meniscus allograft for transplantation.Figure 1.1.Figure 1.2.