Risk Of Iatrogenic Injury Research Articles

The Genitofemoral Nerve Is the Structure Closest to the Tendon Footprint and Is Most at Risk for Iatrogenic Injury During Proximal Adductor Longus Repair: A Cadaveric Anatomy Study

The Genitofemoral Nerve Is the Structure Closest to the Tendon Footprint and Is Most at Risk for Iatrogenic Injury During Proximal Adductor Longus Repair: A Cadaveric Anatomy Study

Assessing Risk of Iatrogenic Peroneal Nerve Injury in All-Inside Lateral Meniscal Repair Between Standard Vs. Arthroscopic MRI.

Various studies have examined the risk of peroneal nerve injury with use of standard magnetic resonance imaging (MRI) of the knee. However, the position of the knee during standard MRI is different from that during an actual arthroscopic lateral meniscal repair. The purpose of the present study was to evaluate and compare the risk of peroneal nerve injury during simulated all-inside lateral meniscal repairs on the basis of MRI scans made with the knee in both positions. With use of axial MRI scans made with the knee in the standard position (i.e., in 30° of flexion) and in the actual position used during arthroscopic lateral meniscal repair (i.e., in a figure-of-4 position), direct lines were drawn to simulate the passage of a straight all-inside meniscal repair device from the anteromedial and anterolateral portals to the medial and lateral borders of the popliteus tendon. The distance from the closest passage of each line to the peroneal nerve was measured. If a line touched or passed through the peroneal nerve, a risk of iatrogenic injury was noted and a new line was drawn from the same portal to the outer border of the peroneal nerve. The danger area was measured from the first line to the new line along the joint capsule. In 28 Thai patients, the shortest distances from each line to the peroneal nerve were significantly shorter on the MRI scans made with the knee in the standard position than on those made with the knee in the arthroscopic position (p < 0.05 for all). All danger areas on the MRI scans that were made with the knee in the arthroscopic position were included within the danger areas on the scans that were made with the knee in the standard position. Standard MRI scans of the knee can be used to determine the risk of peroneal nerve injury at the time of arthroscopic lateral meniscal repair, although the risks are slightly overestimated. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Open Bankart Repair with Subscapularis Split.

Anterior shoulder dislocations are a common injury, especially in the young, active, male population1. Soft-tissue treatment options for shoulder instability include arthroscopic or open Bankart repair, with open Bankart repair historically having lower rates of recurrence and reoperation, faster return to activity2-4, and a similar quality of life compared with arthroscopic repair5. More recent literature has suggested similar recurrence rates between arthroscopic and open procedures6. However, open Bankart repair may be indicated in cases of recurrent instability, especially if the patient participates in high-risk sports, because open repair can provide more capsular shift through the use of extra-capsular knots7. Performing a subscapularis split decreases the likelihood of subscapularis tendon avulsion following subscapularis tendon tenotomy and subsequent repair, as has been described in the literature8. Indications for open Bankart repair include failure of arthroscopic Bankart repair, multiple dislocations, with subcritical bone loss. This surgical technique is performed via the deltopectoral approach. The subscapularis tendon is exposed and "spared" by splitting the fibers with use of a longitudinal incision between the upper 2/3 and lower 1/3 of the subscapularis. We begin the split medially near the myotendinous junction. Because the subscapularis becomes increasingly difficult to separate from the capsule as it tracks laterally, a RAY-TEC sponge is utilized to bluntly dissect. A T-shaped laterally based capsulotomy is made to expose the glenohumeral joint. The vertical aspect is made first, followed by the horizontal aspect from lateral to medial, extending to the labrum. A Fukuda retractor is placed through the split to hold the humeral head laterally. The labrum is elevated, and the glenoid is prepared with rasp. Then labrum is repaired with knotted suture anchors until it is secure. One anchor is utilized for each "hour" of the clock face, with a minimum of 3 anchors. The anchors are placed on the articular margin of the glenoid. Sutures are passed from the anchor through the capsule and tied outside the capsule. The capsulotomy is then repaired with use of a suture. The suture is utilized to pull the inferior portion superiorly. The inferior portion is taken superiorly, and the superior leaflet is imbricated over the top. Finally, an examination is performed to ensure that the humeral head can be translated to but not over the anterior and posterior glenoid rims. No repair of the subscapularis tendon insertion is required. The incision is closed with deep dermal and subcuticular suture. Nonoperative treatment options include rotator cuff and periscapular strengthening or immobilization. Operative treatment options include open Bankart repair with subscapularis tenotomy and repair, arthroscopic Bankart repair, or bone block augmentation procedures. This procedure is different from the alternative treatments in that it is an open procedure, which allows for a more robust repair because the capsule can be shifted and doubled over, leading to the described decreased recurrence and reoperation rates. Open Bankart repair is better suited for large lesions that would be difficult to repair via arthroscopy. This procedure differs from other open Bankart techniques because the subscapularis is split rather than tenotomized, which removes the need to repair the tendon and decreases the rate of avulsion of the subscapularis tendon repair. Finally, this procedure is less invasive than the Latarjet procedure because it does not require osseous osteotomies and fixation. This procedure provides adequate capsular shift and visualization of the Bankart lesion without the increased risk of postoperative subscapularis tendon injury. If the subscapularis split alone does not provide adequate visualization, portions of the subscapularis tendon can be released from the lesser tuberosity.The location and origin of the upper and lower subscapular nerves can have variable courses, which could theoretically put them at risk for iatrogenic injury; however, studies have shown this subscapularis split technique to be safe from and prevent denervation of the muscle. GBL = glenoid bone lossEUA = examination under anesthesiaMRI = magnetic resonance imagingHSL = Hill-Sachs lesionAHCA = anterior humeral circumflex artery.

The Risk of Iatrogenic Posterior Neurovascular Injuries in Lateral Meniscal Repair Based on the Standard Arthroscopic Knee Position: A Magnetic Resonance Imaging Study.

Repair of the posterior horn of the lateral meniscus using an all-inside meniscal repair device involves the risk of iatrogenic posterior neurovascular injuries. Previous studies that have evaluated this risk were based on preoperative magnetic resonance imaging (MRI) with the knee in 30° of flexion and used landmarks that are impractical in the actual operative situation. To use an MRI model simulating actual knee arthroscopic conditions to (1) compare the potential risk of injuries related to the lateral border of the posterior lateral meniscus root (LMR) through the anterolateral versus anteromedial portal and (2) establish "safe" and "danger" zones to reduce the possibility of injuries to posterior neurovascular structures when performing lateral meniscal repair in relation to the lateral border of the posterior LMR. Descriptive laboratory study. Using 29 axial MRI scans of knees in the figure-of-4 position with joint fluid dilatation at the level of the lateral meniscus, direct lines were drawn to simulate a straight all-inside meniscal repair device deployed from the anterolateral and anteromedial portals to the lateral border of the posterior LMR, extending 14 mm beyond the joint capsule. If the line passed through or touched a posterior neurovascular structure, a risk of iatrogenic injuries was noted, and measurements were made to determine the safe zone in relation to the lateral border of the posterior LMR. Repairing the lateral meniscus through the anterolateral portal in relation to the lateral border of the posterior LMR resulted in a significantly greater risk of posterior neurovascular injuries compared with repairing through the anteromedial portal, with injury incidences of 68.97% and 10.35%, respectively (P = .001). The safe zones of lateral meniscal repair through the anterolateral and anteromedial portals were 4.15 ± 1.87 and 6.57 ± 0.98 mm, respectively, beyond the lateral border of the posterior LMR. The risk of posterior neurovascular injuries when repairing posterior lateral meniscal tissue was found to be significantly greater through the anterolateral portal compared with the anteromedial portal. Surgeons can use the safe zones as defined in this study to decrease the risk of iatrogenic posterior neurovascular injuries during arthroscopic lateral meniscal repair.

Poster 265: The Risk of Iatrogenic Posterior Neurovascular Injury in Lateral Meniscal Repair Based on Real Arthroscopic Position: An MRI Study

Objectives: Posterior horn of lateral meniscal repair using an all-inside meniscal repair device involves a risk of iatrogenic posterior neurovascular injury. Some studies have evaluating the injury risk in this area but most were based on preoperative MRIs and landmarks which are difficult to clearly see under actual arthroscopic surgery. To our knowledge, there have been no studies to date evaluating the risk of injury based on MRIs with the knee in the standard operational figure-of-4 position with joint dilatation in arthroscopic lateral meniscal repair related to the lateral border of the lateral meniscal root which is easy to identify during surgery. The objective of this study was to evaluate and compare the risk of posterior neurovascular injury and establish the safe and danger zones in repairing the lateral meniscus through the anterolateral and anteromedial portals in relation to the medial and lateral borders of the lateral meniscal root (LMR) using standard operational figure-of-4 position with joint dilatation MRIs. Methods: This study was descriptive laboratory study. Using 29 axial magnetic resonance imaging (MRI) studies of knees in the figure-of-4 position with joint fluid dilatation at the level of the lateral meniscus, direct lines were drawn to simulate a straight all-inside meniscal repair device deployed from the anteromedial and anterolateral portals to the medial and lateral borders of the LMR extending 14 mm beyond the joint capsule. If the line passed through or touched the posterior neurovascular structure, a risk of iatrogenic injury was noted, and measurements were made to determine the safe zones in relation to the medial or lateral border of the LMR. Results: Repairing the lateral meniscus through the anterolateral portal in relation to the lateral border of the LMR had a significantly greater risk of posterior neurovascular injury than repairing through the anteromedial portal, of which the incidences were 68.97% and 10.35%, respectively (p-value = 0.001). The “safe zones” of lateral meniscal repair in relation to the lateral border of the LMR through the anterolateral and anteromedial portals were 4.15 ± 1.87 mm and 6.57 ± 0.98 mm lateral to the lateral border of the LMR, respectively. Conclusions: Our study found a risk of iatrogenic posterior neurovascular injury when repairing the posterior lateral meniscus tissue through both the anterolateral and anteromedial portals in relation to both the lateral and medial borders of the LMR, with repairs through the anterolateral portal having greater risk than through the anteromedial portal. To reduce this risk, the surgeon can use the “safe zones” as described in this study to decrease the potential risk of iatrogenic posterior neurovascular injury during arthroscopic lateral meniscal repair. Clinical Relevance: Iatrogenic injury is always a concern in any surgery, and the results of this study can be a guide to reducing iatrogenic posterior neurovascular injury during posterior horn of lateral meniscal repair.

Absent celiac trunk and unusual arterial anatomy of the upper abdomen: into the deep.

The celiac trunk is the first major branch of the abdominal aorta. It originates from the ventral aspect of the aorta at the level of T12-L1 vertebrae and was originally described as an artery that branches into the common hepatic artery, left gastric artery, and splenic artery. Absence of the celiac trunk and origin of the three arteries separately from the aorta is a rare entity that is reported in 0.38% to 2.6% of cases. It is even more uncommon that this variation can be accompanied by other vascular variations of the upper abdomen as accessory arteries to the liver, stomach, and pancreas. These cases arise during embryogenesis due to decreased arterial degeneration combined with decreased arterial fusion, which results in the anatomical variations present in the current case. Complex arterial variations are both a risk for iatrogenic injury during surgical procedures and beneficial during endovascular supply as they may provide additional access for embolization and chemotherapy.

Fertility Preservation in Women with Endometriosis.

Several mechanisms have been implicated in the pathogenesis of endometriosis-related infertility. For patients considering surgery, the risk of iatrogenic injury is among the most important factors in the context of fertility preservation, along with age and individual reproductive goals. In the case of endometrioma excision, evidence overwhelmingly demonstrates the negative impact of surgery on ovarian reserve, with significant reductions in antimullerian hormone (up to 30% in unilateral versus up to 44% in bilateral endometriomas). The surgical endometriosis patient should be thoroughly counseled regarding fertility preservation and discussion should include tissue, embryo, and oocyte cryopreservation options. For the latter, data support cryopreservation of 10-15 oocytes in women ≤35 years and over 20 for those >35 years for a realistic chance to achieve one or more live births. When performing surgical interventions for endometriosis, reproductive surgeons should employ fertility-conserving surgical methods to reduce the likelihood of postoperative iatrogenic diminished ovarian reserve.

Arthroscopic accessibility of the first metatarsophalangeal joint for osteochondral defects of the metatarsal head by two-portal technique - comparing joint distraction and plantarflexion

BackgroundSeveral techniques and approaches for first metatarsophalangeal (MTP1) joint arthroscopy have been reported, where joint accessibility plays a key role. This study aimed to evaluate differences in arthroscopic accessibility of the first metatarsal head (MTH1) comparing non-invasive distraction and maximum plantarflexion in a two-portal approach. MethodsForty fresh-frozen lower leg specimens were included and divided into a distraction group (D-group) and a plantarflexion group (PF-group). A two-portal technique (1.9 mm-30°-scope) was used for arthroscopy, maximum reach at the MTH1 was marked. Following arthroscopy, specimens were dissected and examined for iatrogenic injuries. The reached area at the chondral surface was pinned and accessibility calculated. ResultsAccessibility of the MTH1 was 58.03 % ± 13.64 (D-group) and 55.93 % ± 10.30 (PF-group, p = 0.51). The dorsomedial hallucal nerve was injured in one specimen (2.5 %). ConclusionMaximum plantarflexion showed no difference in arthroscopic MTP1 joint accessibility compared to non-invasive distraction in a two-portal approach. During dorsomedial portal placement, the dorsomedial hallucal nerve is at risk for iatrogenic injury.

Identifying safe corridors for anterior pelvic percutaneous instrumentation using computed tomography-based anatomical relationships

IntroductionPercutaneous anterior pelvic ring instrumentation is performed for retrograde screw fixation of ramus fractures, as well as for repair of pubic symphysis diastasis. The anatomic relationships of critical structures around the anterior pelvic ring, such as the spermatic cord and round ligament, have been described in only a few studies regarding the risk of iatrogenic injury during surgery. Our goal is to further describe these relationships, as well as provide radiographic information on safe corridors for percutaneous fixation. MethodsEighty (80) axial computed tomography scans of the abdomen, obtained for non traumatic diagnostic purposes and screened for prior abdominal trauma or procedures, were evaluated by 3 fellowship trained radiologists. Mid-symphyseal cuts were used to obtain several measurements relative to the spermatic cords (SC) or round ligaments (RL): inter-cord or inter-ligament distance, skin to cortex of symphysis distance (vertical), skin to cortex of symphysis distance (oblique), safe corridor distance (between SC/RL and femoral triangle), center safe angle (relative to bilateral ischia), maximal safe angle, and minimal safe angle. ResultsThere were 41 male and 39 female scans included in the final analysis. The average inter-cord distance was 50.2 mm, skin to cortex vertical distance of 43.0 mm, skin to cortex oblique distance of 83.5 mm, safe corridor distance 26.3 mm, center safe angle 19.3˚, maximal safe angle 32.3˚, and minimal safe angle 13.6˚. These were further broken down by range and gender in Table 1. Agreement between radiologists was high for these different measurements with the exception of the skin to cortex oblique distance in female patients and the maximal safe angle in female patients, due to absence of round ligament in a majority of the scans. The round ligament was only present at the mid-symphyseal level for our three reviewers in 37/39, 36/39, and 24/39 of female patient scans. ConclusionsWe have identified defined safe corridors for instrumentation of the anterior pelvic ring that can assist the surgeon in percutaneous application of fixation for fracture care.

Study on the application of preoperative three-dimensional CT angiography of perigastric arteries in laparoscopic radical gastrectomy

To investigate the clinical value and significance of preoperative three-dimensional computerized tomography angiography (CTA) in laparoscopic radical gastrectomy for gastric cancer. The clinical data were analyzed retrospectively from 214 gastric cancer patients. We grouped according to whether to perform CTA, and we compared and analyzed the difference of the data between the two groups. The perigastric arteries were classified according to CTA images of patients in the CTA group. The celiac trunk was classified according to Adachi classification: Type I (118/125, 94.4%), Type II (3/125, 2.4%), Type III (0/125, 0%), Type IV (1/125, 0.8%), Type V (2/125, 1.6%), Type VI (1/125, 0.8%). Hepatic artery classification was performed according to Hiatt classification: Type I (102/125, 81.6%), Type II (9/125, 7.2%), Type III (6/125, 4.8%), Type IV (2/125, 1.6%), Type V (3/125, 2.4%), Type VI (0, 0%), Others (3/125, 2.4%). And this study combined vascular anatomy and surgical risk to establish a new splenic artery classification model. In comparison, the operation time, first exhaust time, and estimated blood loss in the CTA group were significantly lower than those in the non-CTA group. In addition, the blood loss in the CTA group combined with ICG (Indocyanine Green) labeled fluorescence laparoscopy was significantly less than that in the group without ICG labeled. Preoperative CTA could objectively evaluate patients' vascular route and variation and then help us avoid or decrease the risk of vascular injury and bleeding. When combined with ICG labeled fluorescence laparoscopy, it could further reduce the risk of iatrogenic injury during the operation and improve postoperative recovery.

Variations of Cystic Duct and Its Clinical Significance

Background: Cystic duct drains the bile from the gallbladder into the common bile duct. Gallstone disease is one of the most common problems affecting the digestive tract and may lead to many complications. To avoid the complications in these patients the gallbladder is removed surgically (Cholecystectomy). Ligation of cystic duct and cystic artery is a prerequisite procedure when cholecystectomy is done. Understanding about the normal anatomy &amp; the possible variations in biliary ductal system is important for the surgeons for doing cholecystectomy surgery successfully. Errors during gallbladder surgery commonly result from failure to appreciate the common variations in the anatomy of the biliary system. Aim of the study: To find out the incidence of variations in the length, course, and termination of cystic duct in cadavers. Materials and Methods: Present study was done in 50 adult cadavers in the Department of Anatomy, Government Tiruvannamalai medical college, Tamilnadu. Meticulous dissection was done in the hepatobiliary system of these cadavers. Observations: During the study variations in the length of cystic duct, course and different modes of insertion of cystic duct were observed. Conclusion: Knowledge of variations in the length of cystic duct and knowing about different modes of course &amp; insertion of cystic duct is necessary for surgeons while conducting cholecystectomy. The risk of iatrogenic injury is especially high in cases where the biliary anatomy is misidentified prior to surgery. KEY WORDS: Cystic duct, Gallbladder, Cholecystectomy.

“Million dollar nerve” magnetic resonance neurography: first normal and pathological findings

To evaluate prospectively the feasibility of magnetic resonance neurography (MRN) in identifying the anatomical characteristics of thenar muscular branch (TMB) of the median nerve, also known as the "million dollar nerve," in patients and controls. Thirteen patients affected by carpal tunnel syndrome (CTS) and four healthy controls had their hands scanned on a 3-T MR imaging scanner for TMB visualization. Median nerve anatomical variations were classified into four groups according to Poisel's classification system modified by Lanz. TMB signal intensity and diameter were assessed for the diagnosis of neuropathy. TMB was successfully identified in all patients and subjects by using MRN. The most suitable pulse sequences to identify and measure nerve diameter were 3D DW-PSIF and T2-FS-TSE. The axial oblique and sagittal oblique planes are complementary in demonstrating its entire course. TMB had mostly an extraligamentous course with radial side origin (93.8%, each). All patients experienced increased T2 signal intensity (p < 0.001) and thickened nerves. Mean TMB diameters were 1.27 ± 0.21 mm (range, 1.02-1.74 mm) and 0.87 ± 0.16 mm (0.73-1.08 mm) (p = 0.008) in the patient and control groups, respectively. MRN is a reliable imaging technique for identification and anatomical characterization of TMB in patients affected by CTS. This innovative imaging workup may therefore be included in the preoperative evaluation of patients scheduled for carpal tunnel release, especially in CTS with TMB involvement or even in isolated TMB neuropathy. • Magnetic resonance neurography allows precise visualization of the thenar muscular branch of the median nerve. • Thenar muscular branch anatomical variations can be correctly identified. • Preoperative scanning can contribute to reducing the risk of iatrogenic injuries during carpal tunnel release, especially in carpal tunnel syndrome with thenar muscular branch involvement or even in isolated thenar muscular branch neuropathy.

Narrative review of vascular iatrogenic trauma and endovascular treatment

Iatrogenic injury is unfortunately a leading cause of morbidity and mortality for patients worldwide. The etiology of iatrogenic injury is broad, and can be seen with both diagnostic and therapeutic interventions. While steps can be taken to reduce the occurrence of iatrogenic injury, it is often not completely avoidable. Once iatrogenic injury has occurred, prompt recognition and appropriate management can help reduce further harm. The objective of this narrative review it to help reader better understand the risk factors associated with, and treatment options for a broad range of potential iatrogenic injuries by presenting a series of iatrogenic injury cases. This review also discusses rates, risk factors, as well as imaging and clinical signs of iatrogenic injury with an emphasis on endovascular and minimally invasive treatments. While iatrogenic vascular injury once required surgical intervention, now minimally invasive endovascular treatment is a potential option for certain patients. Further research is needed to help identify patients that are at the highest risk for iatrogenic injury, allowing patients and providers to reconsider or avoid interventions where the risk of iatrogenic injury may outweigh the benefit. Further research is also needed to better define outcomes for patients with iatrogenic vascular injury treated with minimally invasive endovascular techniques verses conservative management or surgical intervention.

The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study.

Cerebral stroke continues to be one of the leading causes of mortality and long-term morbidity; therefore, carotid endarterectomy (CEA) remains to be a popular treatment for both symptomatic and asymptomatic patients with carotid stenosis. Cranial nerve injuries remain one of the major contributor to the postoperative morbidities. Anatomical dissections were carried out on 44 sides of 22 cadaveric heads following the classical CEA procedure to investigate the variations of the local anatomy as a contributing factor to cranial nerve injuries. Concurrence of two variations was found to be important in hypoglossal nerve injury: the presence of a direct smaller vein in proximity of the carotid bifurcation, and the intersection of the hypoglossal nerve (HN) with this vein. Based on the sample investigated, this variation was observed significantly higher on the right side. Awareness of possible anatomical variations and early ligation of any small veins can significantly decrease iatrogenic injury risk.

The determination of safe zones for arthroscopic portal placement into the posterior knee by mapping the courses of neurovascular structures in relation to bony landmarks.

Minimally invasive surgery in the posterior knee is high risk for iatrogenic injury to popliteal neurovascularneurovasculature structures. This study aimed to use reliable landmarks to define safe zones for arthroscopic portal placement into the posterior knee. Distances were measured between bony landmarks and neurovascular structures within the popliteal fossa using 45 formalin-embalmed cadavers: small saphenous vein (SSV), medial (MCSN) and lateral (LCSN) cutaneous sural nerves, tibial nerve (TN), common fibular nerve (CFN), popliteal vein (PV) and artery (PA). The structures were measured in relation to medial (MEF) and lateral (LEF) femoral epicondyle, medial (MCT) and lateral (LCT) tibial condyle and the midpoint between the landmarks. The mean distance (mm) between MEF and structures was, male and female, respectively: SSV 37.6 + 12.5, 37.9 + 8.2; MCSN 39.2 + 14, 38.8 + 10.1; TN 39.4 + 10.2, 38.0 + 8.1; PV 38.4 + 12.9, 32.8 + 5.6; PA 38.4 + 12.1, 34.6 + 4.9. At midpoint and MCT all structures medialized between 5 and 28%. The mean distance between LEF and structures was, male and female, respectively: CFN 13.4 + 8.2, 8.4 + 9.1; LCSN 24.9 + 7.3, 18.4 + 10.4. At midpoint and LCT the CFN lateralized by 37-42% and the LCSN medialized by 8-9%. Results suggest posteromedial portal placement can be safely established < 20mm from the medial femoral epicondyle, tibial condyle or the midpoint between the two landmarks. Posterolateral portal placement is of higher risk, and entry point is 18mm from the lateral femoral epicondyle, tibial condyle or the midpoint between the two landmarks in males and 12mm in females. These landmarks will allow safe portal placement in 99% of cases.

Ex vivo study of vagal branches at risk for iatrogenic injury during laryngoplasty in horses.

To localize vagal branches within the surgical field of laryngoplasty and identify potentially hazardous surgical steps. Observational cadaveric study. Five equine head-neck specimens and four entire equine cadavers. Dissection of the pharyngeal region from a surgical perspective. Neuronal structures were considered at risk if touched or if the distance to instruments was less than 5 mm. The branches of the pharyngeal plexus (PP) supplying the cricopharyngeal muscle (PPcr), the thyropharyngeal muscle (PPth), and the esophagus (PPes) were identified in the surgical field in nine of nine, five of nine, and one of nine specimens, respectively. The internal branch of the cranial laryngeal nerve (ibCLN) was identified within the carotid sheath in six of nine specimens. The external branch of the cranial laryngeal nerve (ebCLN) was identified close to the septum of the caudal constrictors in nine of nine specimens. The blade of the tissue retractor compressed the ibCLN in six of six, the ebCLN in four of six, the PPcr in six of six, the PPth in two of three, and the PPes in two of two specimens in which the respective nerves were identified after further dissection. Surgical exploration of the dorsolateral aspect of the pharynx and the incision of the septum of the caudal constrictors harmed the ebCLN in nine of nine, PPcr in seven of nine, and PPth in four of eight specimens. Several vagal branches were located in the surgical field and must be considered at risk because of their location. Use of the tissue retractor, dissection over the pharynx, and dissection of the septum of the caudal constrictors involve a risk to damage vagal branches.

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Because of plate development, it is now possible to perform tibial plateau leveling osteotomy (TPLO) in small-breed dogs with cranial cruciate ligament rupture. Compared with conventional treatment, faster walking and better function are reported post-TPLO. However, TPLO can be more difficult in toy-breed dogs than large-breed dogs. Because of the smaller bones, it is difficult to manipulate the bone fragments during surgery, and small movements of bones can cause major differences in limb alignment. In TPLO, a jig is conventionally recommended to increase the accuracy of alignment; however, installation of the jig can be difficult in small-breed dogs, and it may cause problems such as iatrogenic fracture. The present study thus aimed to evaluate the accuracy of TPLO without a jig in toy-breed dogs. Paired stifles (n=22) obtained from 11 toy-breed dogs cadavers (body weight range, 2.0-7.4 kg) were randomly assigned to a jig or non-jig group. Radiographic images were obtained preoperative and postoperative TPLO. Tibias were dissected from the hindlimb and measured for evaluation of accuracy. The following postoperative parameters were compared: tibial plateau angle, mechanical medial proximal tibial angle, osteotomy location, tibia crest thickness, gap between segments, and orientation line angles. There were no significant differences between the two groups, demonstrating that jig usage does not affect precision of TPLO in toy-breed dogs. Therefore, it is better not to use a jig in toy-breed dogs with relatively small bones, considering the risk of iatrogenic injury, cost and operation time

Dual-incision minimally invasive fasciotomy of the anterior and peroneal compartments for chronic exertional compartment syndrome of the lower leg

To evaluate the risk of iatrogenic injury when using a dual-incision minimally invasive technique to decompress the anterior and peroneal compartments of the lower leg. Forty lower extremities from 20 adult cadavers, embalmed with Thiel’s method, were subject to fasciotomy of the anterior and peroneal compartment using a dual-incision minimally invasive fasciotomy. The first incision was made 12 cm proximal to the lateral malleolus to identify and protect the superficial peroneal nerve (SPN). The second incision was made at the mid-point of the Fibula (half-way between the fibular head and the lateral malleolus). Release of the anterior and peroneal compartments was successful in all specimens. Two nerve injuries of the superficial peroneal nerve were reported. More precisely, in these cases the medial dorsal cutaneous nerve got injured during the fascial opening of the extensor compartment. Two incision minimally invasive fasciotomy to decompress the anterior and peroneal compartments of the lower leg appears to be safe with regard to the results of this study.

Deep gluteal space anatomy and its relationship with deep gluteal pain syndromes.

Increasing interest has been seen in understanding the anatomy and biomechanics involved in the Deep Gluteal Syndrome, therefore the main objective of our paper was to define the anatomy of the deep gluteal space concerning the important osseous, muscular and neurological structures. 12 cadaveric models (24 hemipelvises) were used. We proceeded with classical anatomic dissection and evaluated numerous osseous, musculotendinous and neurologic structures and their relationships. We also determined the femoral anteversion and neck-shaft angles. We found that 15.4% of lower limbs examined presented variations in the sciatic nerve (SN) emergence, and this was significantly longer in men. The distance from the SN to the trochanteric region was also significantly lower in males.The average ischiofemoral distance (IFD) was 2.5 ± 1.3 cm, at the same time that the structures comprised in that space showed superior areas, such as the quadratus femoris (QF) with 5.0 ± 1.1 cm and the SN with 1.4 ± 0.3 cm widths.Besides that, we also evaluated the distance from the SN to the lesser trochanter (LT) and the ischial tuberosity (IT), in the ischiofemoral space, reaching average values of 1.1 ± 0.7 cm and 1.5 ± 0.6 cm respectively.Regarding the relationship between the proximal hamstring insertion, we verified that the LT was at an average distance of 1.6 ± 1.1 cm, that the SN was only 0.2 ± 0.3 cm lateral to it, and the PN is just 2.6 ± 1.2 cm proximal to it. Our study confirmed the extreme variation in the SN origin that can contribute to the Piriformis syndrome. The IFD obtained in our study showed that this distance was small for the structures contained in this space.The proximal hamstring insertion showed a significantly more extended footprint in males, which puts the pudendal nerve (PN) at higher risk of iatrogenic injury.

The Accessory Medial Portal for Anterior Cruciate Ligament Reconstruction: A Safe Zone to Avoid Neurovascular Complications.

Background:The accessory medial portal (AMP) used for anatomic anterior cruciate ligament reconstruction (ACLR) is gaining popularity. This portal is routinely created at 60° of knee flexion, placing the infrapatellar branch of the saphenous nerve (IBSN) and, less commonly, the descending and superior medial genicular arteries at risk.Purpose/Hypothesis:The purpose of this study was to identify a safe zone for AMP placement in ACLR to minimize the risk of injury to the IBSN. We hypothesized that increased knee flexion angles would decrease the risk to neurovascular structures when creating an AMP.Study Design:Descriptive laboratory study.Methods:A total of 20 cadaveric (10 matched pairs) knees were used for dissection to identify the IBSN and other neurovascular structures. A 30° arthroscope was used to make the central medial portal and AMP at 3 knee flexion angles (60°, 90°, and 110°). Distances were measured from the AMP to branches of the IBSN. Safety of AMP placement was analyzed by assessing the frequency at which spinal needles pierced a neurovascular structure or violated a safe zone.Results:The superior IBSN was significantly closer to the AMP than inferior IBSN. The AMP was significantly farther from the superior IBSN at 110° (8.56 ± 5.28 mm) compared with 60° (5.63 ± 5.00 mm; P = .015) and 90° (6.69 ± 5.03 mm; P = .006). A triangular safe zone was identified at 110° of knee flexion. No neurovascular structures were pierced, and the IBSN was not present in the safe zone. At 90°, the IBSN was not pierced; however, the IBSN did violate the safe zone at 90° of knee flexion.Conclusion:The superior IBSN is at risk for iatrogenic injury with an AMP placed at 60° of knee flexion. The nerve moved distally with knee flexion. While no neurovascular structures were compromised at 90° of knee flexion, the nerve was found to course through the safe zone. A safe zone at 110° of knee flexion decreases the risk of neurovascular injury and makes the AMP safe for ACLR.Clinical Relevance:The AMP at 60° of knee flexion for ACLR poses risk to the IBSN. The IBSN did violate the safe zone at 90° of flexion. We recommend creating an AMP with increased knee flexion to 110° to decrease the risk of iatrogenic injury. When establishing an AMP, one should aim for the center of the defined safe zone, given that the spinal needle used in this study has a smaller diameter than a stab incision.