Quantification of Acetabular Coverage on 3-Dimensional Reconstructed Computed Tomography Scan Bone Models in Patients With Femoroacetabular Impingement Syndrome: A Descriptive Study

Background: Accurate assessment of osseous morphology is imperative in the evaluation of patients with femoroacetabular impingement syndrome (FAIS) and hip dysplasia. Through use of computed tomography (CT), 3-dimensional (3D) reconstructed hip models may provide a more precise measurement for overcoverage and undercoverage and aid in the interpretation of 2-dimensional radiographs obtained in the clinical setting. Purpose: To describe new measures of acetabular coverage based on 3D-reconstructed CT scan bone models. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Preoperative CT scans were acquired on the bilateral hips and pelvises of 30 patients before arthroscopic surgical intervention for FAIS. Custom software was used for semiautomated segmentation to generate 3D osseous models of the femur and acetabulum that were aligned to a standard coordinate system. This software calculated percentage of total acetabular coverage, which was defined as the surface area projected onto the superior aspect of the femoral head. The percentage of coverage was also quantified regionally in the anteromedial, anterolateral, posteromedial, and posterolateral quadrants of the femoral head. The acetabular clockface was established by defining 6 o’clock as the inferior aspect of the acetabular notch. Radial coverage was then calculated along the clockface from the 9-o’clock to 5-o’clock positions. Results: The study included 20 female and 10 male patients with a mean age of 33.6 ± 11.7 years and mean body mass index of 27.8 ± 6.3. The average percentage of total acetabular coverage for the sample was 57% ± 6%. Acetabular coverages by region were as follows: anteromedial, 78% ± 7%; anterolateral, 18% ± 7%, posterolateral, 33% ± 13%, and posteromedial, 99% ± 1%. The acetabular coverage ranged from 23% to 69% along the radial clockface from 9 to 5 o’clock. Conclusion: This study demonstrated new 3D measurements to characterize acetabular coverage in patients with FAIS and elucidated the distribution of acetabular coverage according to these measurements.

EP.TU.439Falciform ligament torsion – a rare cause of the acute abdomen

The falciform ligament attaches the liver to the anterior abdominal wall and diaphragm. Acute falciform ligament related pathology is rare. In this case report we present a case of acute fat necrosis related to the falciform ligament. A 53 year old women presented with acute upper abdominal pain localised to the right hypochondrium. He was tender to palpation in the same region with a positive Murphy’s sign. A provisional diagnosis of acute cholecystitis was made. Blood work revealed raised inflammatory markers but normal liver function tests. Abdominal ultrasound revealed no gallbladder pathology nor gallstones. Thus computed tomogram (CT) scan of the abdomen was performed, showing hyper-attenuation rim signal present within the inferior aspect of the falciform ligament consistent with local vascular occlusion. The patient was managed with intravenous antibiotics with liberal analgesia and went on to make a successful recovery. Only 10 cases have been reported in the literature related to falciform ligament necrosis. We present this unusual pathology encountered on our acute surgical take, to alert surgeons to this rare diagnosis and provide a review of the literature and provide detail of how such a pathology manifests on CT scan.

An atypical presentation of a multiloculated giant pseudocyst of pancreas

Giant pseudocysts of the pancreas are rare and difficult to manage. Pseudocysts are usually treated by cystogastrostomy but dependent drainage for giant pseudocysts may require alternative methods like cystojejunostomy. We report here a rare case of a multiloculated giant pseudocyst of pancreas which presented atypically with protrusion through the lesser omentum. The pseudocyst protruding through the lesser omentum filled the whole upper abdomen up to umbilical region and displaced the stomach inferiorly. The stomach which is usually displaced anteriorly by pseudocysts was unusually displaced and splayed on the inferior aspect of the pseudocyst. The anterior wall of the fundus and body of the stomach was adherent to the inferior aspect of the pseudocyst. The pseudocyst was managed by draining into the stomach in a different way by performing a cystogastrostomy to the anterior wall of the stomach. Giant pseudocysts are difficult to manage, and good imaging studies are helpful in selecting surgical options for dependent drainage. Cystogastrostomy on the anterior wall of the stomach is a feasible option to drain pseudocysts which are predominantly overlying and adherent to the anterior wall of the stomach.

Gasserian ganglion radiofrequency thermoablation in a patient with aneurysm of the anterior communicating artery

BackgroundGasserian ganglion radiofreqeucy thermoablation is a good treatment option for the management of pain in trigeminal neuralgia. We report a case in which the patient of trigeminal neuralgia combined with anterior cerebral artery aneurysm was treated successfully by gasserian ganglion thermoablation without any complication.CaseAn 85-year-old female presenting with electric shock like sensation in the gum and molar teeth was diagnosed as trigeminal neuralgia. Carbamazepine medication and trigeminal nerve blockade relieved her pain partially, but severe side effects of carbamazepine occurred. Magnetic resonance angiography of the brain showed saccular aneurysm in inferior aspect of the anterior communicating artery. Gasserian ganglion thermoablation under sedation anesthesia using nicardipine was performed carefully without any rupture of the cerebral aneurysm.ConclusionsGasserian ganglion thermoablation could be performed safely in a patient with cerebral aneurysm without any inadvertent event.

Microsurgical resection of a giant cervico-medullary ependymoma: 2D-dimensional video

Background: Ependymoma is a slowly growing benign neoplasm that constitutes 3–9% of all neuroepithelial spinal cord tumors.[3,4] They rarely involve the cervicomedullary junction where they both compress the distal brainstem and upper cervical cord. Due to the critical contiguous structures, gross total resection of these lesions may result in significant morbidity/mortality.[1,2] Utilizing intraoperative neuromonitoring can help limit the risks of removing these lesions. Not when considering the risk/complications of partial versus total resection, the surgeon should keep in mind that they are benign slow growing tumors with relatively good long-term survivals following partial removals. This surgical video shows the surgical strategy and management of a giant cervicomedullary ependymoma performed in a 23-year-old female. Case Description: A 23-year-old female presented with cervical pain and quadriparesis of 1-year’s duration. The MR with/without gadolinium showed a large intradural, intramedullary cervical spinal cord tumor that severely expanded the spinal cord. It contained a significant cystic component, extending from the lower brain stem to the inferior aspect of C7. The lesion was hyperintense on T1 and T2 sequences and demonstrated minimal contrast enhancement. Surgery warranted a posterior cranio-cervical midline approach consisting of a suboccipital craniectomy with laminotomy. The pathological diagnosis was consistent with an ependymoma (WHO I). Fifteen days postoperatively, the patient was discharged with a minimal residual quadriparesis that largely resolved within 6 postoperative months. Three months later, the MRI confirmed complete tumor removal of the lesion. Notably, longer-term follow-up is warranted before complete excision can be confirmed. If there is a recurrence, repeat resection versus stereotactic radiosurgery may be warranted. Conclusion: This video highlights a safe and effective surgical technique for the resection of a giant cervicomedullary ependymoma.

Elliptical heads result in increased glenohumeral translation along with micro-motion of the glenoid component during axial rotation in total shoulder arthroplasty

Introduction Elliptical-shaped humeral head prostheses have recently been proposed to reflect a more anatomic shoulder replacement. However, its subsequent effect on micro-motion of the glenoid component is still not understood. Materials and methods Six fresh-frozen, cadaveric shoulders (mean age: 62.7 ± 9.2 years) were used for the study. Each specimen underwent total shoulder arthroplasty using an anatomic stemless implant. At 15°, 30°, 45° and 60° of glenohumeral abduction, 50° of internal and external rotations in the axial plane were alternatingly applied to the humerus with both an elliptical and spherical humeral head design. Glenohumeral translation was assessed by means of a 3-dimensional digitizer. Micro-motion of the glenoid component was evaluated using four high-resolution differential variable reluctance transducer strain gauges, placed at the anterior, posterior, superior, and inferior aspect of the glenoid component. Results The elliptical head design showed significantly more micro-motion in total and at the superior aspect of glenoid component during external rotation at 15° (total: P = 0.004; superior: P = 0.004) and 30° (total: P = 0.045; superior: P = 0.033) of abduction when compared to the spherical design. However, during internal rotation, elliptical and spherical heads showed similar amounts of micro-motion at the glenoid component at all tested abduction angles. When looking at glenohumeral translation, elliptical and spherical heads showed similar anteroposterior and superoinferior translation as well as compound motion during external rotation at all tested abduction angles. During internal rotation, the elliptical design resulted in significantly more anteroposterior translation and compound motion at all abduction angles when compared to the spherical design (P < 0.05). Conclusion In the setting of total shoulder arthroplasty, the elliptical head design demonstrated greater glenohumeral translation and micro-motion at the glenoid component during axial rotation when compared to the spherical design, potentially increasing the risk for glenoid loosening in the long term. Level of evidence Controlled Laboratory Study

Arthroscopic Repair of the Bankart Lesion Using Dual-Row Labral Repair

Background: The most common technique described for bankart repair is the single-row labral repair. Recent interest has been the use of a dual-row, double pulley technique, first described by Zhang et al and popularized by Millett et al as the “bony Bankart bridge” technique. The aim of this study is to report a double-row all-suture labral fixation technique using knotless anchors. Technique: Step 1: glenohumeral debridement, and preparation of the glenoid labral and Bankart. The patient is first placed in the beach-chair position and surface landmarks are created. The standard posterior portal is first created and the glenohumeral joint is evaluated. Once the lesion is identified, the relevant working anterosuperior and anteroinferior portals are established using the outside-in technique. The synovitis is debrided to allow visualization and the labrum is liberated from the anterior glenoid. The Bankart lesion fragment is liberated, and partial fragments are osteotomized. With the anterolateral portal as the viewing portal, the anterior rim of the glenoid is now decorticated using a motorized shaver and rasp to create a bleeding bony surface. Step 2: the low rim anchor (5:30 o’clock). At the anterior-inferior aspect of the glenoid, the drill guide is positioned as low as possible (5:30 o’clock position for the right shoulder) and about 7 to 10 mm medial to the rim of the glenoid. The first 1.8 mm single-loaded suture anchor (Q-FIX All-Suture Anchor) is then inserted via the posterior portal. Step 3: the anterior-inferior-medial (AIM) anchor (4 o’clock). Step 4: the knotless high rim anchor (3 o’clock). Step 5: tying of sutures. The sutures from each anchor are tied in a mattress configuration, eventually creating a suture bridge over the labral repair Discussion/Conclusion: This dual row labral repair technique allows for maximum compression and contact between the fragment and the glenoid bed, allowing healing over a contact area rather than just the rim. The other added advantage is the use of curved tip anchors which allow negotiation of difficult corners, especially in the 5 to 6 o’clock position.

Lymphangioma of popliteal fossa masquerading as Baker’s cyst

Background Lymphatic malformations are the second most common vascular malformations after venous malformations. These slow-flow lesions occur most often in the paediatric population and seldom in the extremities. We report a case of lymphangioma at the popliteal fossa in an adult who underwent complete surgical resection. Case presentation A 30-year-old male presented to the department of orthopaedics with a swelling in the right calf region. Clinically, it was suspected to be a Baker’s cyst. Ultrasound showed a multiloculated anechoic cystic lesion in the inferior aspect of popliteal fossa along the intermuscular plane with multiple internal septations. Infected Baker’s cyst was considered, and MRI was suggested for further evaluation. On MRI, the lesion measured 7.2 × 4.6 × 5.8 cm, appeared as a low signal on T1 and high signal on STIR and T2, with multiple internal septations and was situated in the inferior aspect of the right popliteal fossa along the intermuscular plane between the lateral head of gastrocnemius and soleus muscles. No obvious synovial extension. A post-contrast study showed minimal peripheral and septal enhancement. Neither internal enhancing solid components nor significant internal derangement of the knee was observed. Diagnosis of lymphangioma was considered based on the imaging features and ruling out the common differentials for cystic lesions around the knee. Wide local excision was performed. Histopathological evaluation showed multiple irregularly dilated lymphatic channels lined by flatted epithelium. The lymphatic channels were seen to be surrounded by thick fibro collagenous cyst wall with scattered congested blood vessels, skeletal muscle fibre and chronic inflammatory cells. Conclusion Lymphangioma must be included in the differential diagnosis of any cystic lesion if the lesion appears multiseptated and/or infiltrative. At the popliteal fossa, it presents as a multiseptated cyst with no synovial continuity or internal derangement of the knee.

A Case of an Ectopic Parathyroid Adenoma With a Concomitant 99mTc-sestamibi-avid Papillary Thyroid Carcinoma

Background: The evaluation and management of parathyroid adenomas have improved over the years. Localization of parathyroid adenomas in patients with primary hyperparathyroidism was simplified with the use of 99mTc-sestamibi scintigraphy. In the advent of minimally invasive parathyroid surgery, use of radionuclide probes reduced the need for neck exploration and intraoperative frozen section leading to fewer complications, shorter operative time and hospitalization and rapid postoperative recovery. However, limitations of these techniques should be taken into consideration in certain cases. Clinical Case: A 60 year-old female diagnosed with primary hyperparathyroidism presented with recurrent nephrolithiasis and osteoporosis. Initial laboratory evaluation showed elevated serum calcium and intact PTH (1.54 mmol/L and 146 pg/mL, respectively). 99mTc-sestamibi scintigraphy showed a sestamibi-avid focus in the inferior aspect of the right lobe suggestive of a parathyroid adenoma or hyperplasia. Pre-operative neck ultrasound showed non-specific thyroid parenchymal changes and nodules on both lobes with benign sonographic features. She underwent radionuclide-guided focused right parathyroidectomy. The identified enlarged right inferior parathyroid gland registered a highest reading of 70 cps on radionuclide probe. Post-operatively, repeat intact PTH level was still elevated (171.2 pg/mL). There was an interval non-demonstration of the sestamibi-avid focus in the inferior aspect of the right thyroid lobe with an increased sestamibi uptake in the left thyroid lobe compared to the previous parathyroid scan. Histopathologic examination showed a normocellular parathyroid gland and a multifocal papillary thyroid carcinoma. She underwent total thyroidectomy with central neck dissection and 4 parathyroid gland exploration with intraoperative parathyroid hormone assay. However, serial PTH monitoring after left inferior parathyroidectomy and after bilateral partial superior parathyroidectomy still showed elevated levels. Histopathologic examination showed mildly enlarged, normocellular parathyroid gland. The bilateral carotid sheath, retropharyngeal region and superior mediastinum were explored but no ectopic parathyroid tissues were seen. Post-operatively, calcium and PTH were still elevated (1.48 mmol/L and 200.5 pg/mL, respectively). Conclusion: This case highlights the predicaments in the management of parathyroid adenomas, recognizing the possibility of false-positive sestamibi scans due to malignant thyroid nodules and the possibility of the two diseases occurring concurrently, albeit rare.

A226 INCIDENTAL FINDING OF A LARGE GASTRIC VARIX ASSOCIATED WITH NEONATAL UMBILICAL VEIN CANALIZATION

Results A 41-year old Asian male, who immigrated to Canada many years ago, and who had previously been successfully treated for Helicobacter pylori infection underwent gastroscopy for investigation of dyspepsia. His gastroscopy was normal except for a large subepithelial abnormality that was noted close to the gastroesophageal junction. Routine gastric biopsies from the antrum and body were normal. Subsequent endoscopic ultrasound revealed flow through the anechoic tortuous lesion and confirmed it was a very large isolated gastric varix type 1. Abdominal CT scan revealed chronic occlusion of the portal vein, splenic vein, and the portal confluence with extensive collateralization in the upper abdomen. There was complete cavernous transformation of the portal vein. Of the numerous varices in the upper abdomen, a very large varix drained into the left renal vein and indented into the posterior wall of the fundus of the stomach which accounted for the endoscopic finding. Multiple mesenteric veins were identified that connected to varices adjacent to the inferior aspect of the pancreas and duodenum. Notably, there was no evidence of cirrhosis or chronic pancreatitis. Liver enzymes, albumin, and INR were normal. Further collateral history revealed that he was hospitalized as a neonate for pneumonia with catheterization of the umbilical vein, which is known to be associated with thrombosis of the portal vein. Conclusions Detection of congenital absence of the portal vein (CAPV) is recognized more often due to advances in diagnostic imaging. Radiologically, the absence of the portal vein in CAPV is distinguished from portal vein thrombosis by the lack of venous collaterals or sequalae of portal hypertension, such as ascites or splenomegaly. A more gradual thrombosis of the portal vein may permit collaterals to develop without acute changes and is not equivalent to portal vein aplasia or agenesis as intrahepatic bile ducts are normal. The gold standard for diagnosis of CAPV is histologic absence of the portal vein in the liver on catheter angiography. CAPV is associated with abnormal embryologic development of the portal vein and frequently presents with complications of portal hypertension or portosystemic encephalopathy or the sequalae of venous shunts, hepatic or cardiac abnormalities found on imaging. Our case is an incidentally discovered absence of the portal venous system due to chronic thrombosis with extensive collateralization and an enlarged gastric varix protruding into the proximal stomach. It is well documented that canalization of the umbilical vein in infancy is associated with portal vein thrombosis, with incidences up to 68%. This case highlights the importance of eliciting a childhood hospitalization history in cases of non-cirrhotic portal hypertension. Funding Agencies None