The Femoral Nerve and Its Relationship to the Lateral Circumflex Femoral Artery

Soft Tissue Lengthening for Flexion Dislocation of Patella

PURPOSE OF REVIEW

Obligatory dislocation of the patella (also known as habitual dislocation) is a rare subset of patellofemoral instability in which the patella dislocates every time the knee is flexed. The problem arises due to contracture of the quadriceps muscles. Soft tissue lengthening procedures such as quadriceps tendon lengthening are the mainstay of treatment, in contrast to medial patellofemoral reconstruction (MPFL-R) for the more common recurrent lateral patellar dislocation. The current review explores the existing literature surrounding the pathophysiology and treatment strategies for this unique cause of knee instability.

RECENT FINDINGS

Flexion dislocation of the knee often presents in children when they begin to walk. It is also termed obligatory or habitual because the patella dislocates laterally with each flexion and extension cycle of the knee. In contrast to other forms of patellar dislocation, the displacement is painless in obligatory dislocation. Likewise, the underlying biomechanical cause of this issue is related to contracture of tissues lateral to the patella rather than disruption of medial soft tissues as seen in recurrent/traumatic dislocation or subluxation of the patella. A number of procedures have been described for management of obligatory dislocation of the patella, with the general consensus that a combination of procedures including release/lengthening of the proximal lateral soft tissues as a critical component for a successful outcome. Soft tissue release/lengthening has been performed for over 50 years to treat obligatory dislocation of the patella. This procedure must be used in combination with other proximal and distal reconstructive with careful intraoperative assessment of knee flexion and patellar tracking for satisfactory outcomes. Further research using standardized outcome measures is needed to identify the optimal step-wise approach in treatment of obligatory patellar dislocation.

Postoperative Femoral Nerve Palsy and Meralgia Paresthetica after Gynecologic Oncologic Surgery

Femoral nerve palsy and meralgia paresthetica following gynecologic cancer surgery are rare, but severe and long lasting. Here, we aimed to study their incidence, severity, possible risk factors and its time to remission. Between January 2008 and December 2017 976 gynecologic cancer patients were identified in our institutional database receiving surgery. Complete patient charts were reviewed retrospectively. Possible risk factors were analyzed by Fisher’s exact test. 441 (45.18%) out 976 were treated for Ovarian cancer. In total 23 patients were identified with a postoperative neurological leg disorder. A femoral nerve palsy was present in 15 patients (1.5%) and a meralgia paresthetica in 8 patients (0.82%). Three patients showed both disorders. Duration of surgery (p = 0.0000), positioning during surgery (p = 0.0040), femoral artery catheter (p = 0.0051), prior chemotherapy (p = 0.0007), nicotine abuse (p = 0.00456) and prior polyneuropathy (p = 0.0181) showed a significant association with a postoperative femoral nerve palsy. Nicotine abuse (p = 0.0335) and prior chemotherapy (p = 0.0151) were significant for the development of a meralgia paresthetica. Long lasting surgery, patient positioning and femoral arterial catheter placement are risk factors for a postoperative femoral nerve palsy in gynecologic cancer surgery. Polyneuropathy, nicotine abuse, and prior chemotherapy are predisposing risk factors for a femoral nerve palsy and a meralgia paresthetica. A resolution of symptoms is the rule for both disorders within different time schedules.

A Vascular Obstacle in Ultrasound-Guided Hip Joint Injection

Background:

We evaluated the risk of lateral circumflex femoral artery (LCFA) injury during ultrasound-guided intra-articular hip injections.

Methods:

This study was divided into three parts. (1) Four ultrasound-guided hip injections were performed on human cadavers. With needles in place, tissues were dissected to expose the LCFA. (2) Ultrasound-trained rheumatologists marked a planned needle trajectory from skin to hip joint on live human ultrasound images during an Observed Structured Clinical Examination (OSCE). Doppler was subsequently activated to locate the LCFA, and the distance between trajectory and arterial signal was recorded. (3) Rheumatologists certified in musculoskeletal ultrasound were surveyed about joint injection vascular complications.

Results:

(1) In one of the four cadaveric dissections, the needle made direct contact with the LCFA. (2) Of 27 OSCE participants, only two activated Doppler before marking simulated hip injection trajectories. Trajectories passed through LCFA Doppler signal in six (22%) cases. Mean minimal distance from trajectory to arterial signal was 4 mm (range, 0–11 mm). (3) Of 62 survey respondents, 24% stated that they did not use Doppler routinely. While none reported bleeding injuries with their patients, 16% knew of a hip injection-related vascular complication performed by another provider.

Conclusion:

There is a risk of LCFA injury during ultrasound-guided hip joint injection. Routine use of Doppler should be considered in standard hip injection protocols.

Deep and superficial circumflex iliac arteries and their relationship to the ultrasound-guided femoral nerve block procedure: A cadaver study

The in-plane lateral to medial approach is a standard technique for ultrasound-guided femoral nerve block (USG-FNB). The first bifurcation of the femoral artery, which consists of the deep artery of the thigh (DAT) or occasionally the lateral circumflex femoral artery (LCFA), is regarded as the distal border for this procedure. We sometimes detect arteries along the estimated needle trajectory for USG-FNB. The superficial (SCIA) and deep (DCIA) circumflex iliac arteries run laterally parallel to the inguinal ligament from the femoral or external iliac artery. The relationship between the SCIA and DCIA and other anatomical structures related to USG-FNB around the femoral triangle region was studied by gross anatomical examination of 100 formalin-fixed adult cadavers. At least one SCIA and one DCIA were identified around each femoral triangle; 81.8% of SCIA and 58% of DCIA originated from the femoral artery. All DCIA coursed between the fascia lata and fascia iliaca and 80% of SCIA penetrated the fascia lata. In 94% of femoral triangles, at least one arterial branch heading towards the lateral part of the thigh originated from the femoral artery from the level of the inguinal ligament to the first bifurcation of the femoral artery. The presence of SCIA and DCIA should be considered during USG-FNB using the in-plane lateral to medial approach to avoid inadvertently injuring them, as they are occasionally located along the presumed needle trajectory superficial to the fascia iliaca. Clin. Anat. 30:413-420, 2017. © 2017 Wiley Periodicals, Inc.

Regional anesthesia for pediatric knee surgery: a review of the indications, procedures, outcomes, safety, and challenges

The indications for surgery on the knee in children and adolescents share some similarity to adult practice in that there are an increasing number of sports-related injuries requiring surgical repair. In addition, there are some unique age-related conditions or congenital abnormalities that may present as indications for orthopedic intervention at the level of the knee. The efficacy and safety of peripheral nerve blocks (PNBs) for postoperative analgesia following orthopedic surgery has been well established in adults. Recent studies have also demonstrated earlier functional recovery after surgery in patients who received PNBs. In children, PNB is gaining popularity, and increasing data are emerging to demonstrate the feasibility, efficacy, and safety in this population. In this paper, we will review some of the most common indications for surgery involving the knee in children and the anatomy of knee, associated dermatomal and osteotomal innervation, and the PNBs most commonly used to produce analgesia at the level of the knee. We will review the evidence in support of regional anesthesia in children in terms of both the quality conferred to the immediate postoperative care and the role of continuous PNBs in maintaining effective analgesia following discharge. Also we will discuss some of the subtle challenges in utilizing regional anesthesia in the pediatric patient including the use of general anesthesia when performing regional anesthesia and the issue of monitoring for compartment syndrome. Finally, we will offer some thoughts about areas of practice that are in need of further investigation.

Anatomical variations of the profunda femoris artery and its branches-a cadaveric study in South Indian population

The variations of the profunda and its branches are numerous, and, to a considerable extent, largely associated with one another. In occlusion of the Superficial femoral artery, the profunda femoris artery forms an effective collateral bed between the ileo-femoral segment and the popliteal artery and its branches. This study based on dissections performed on 40 properly embalmed human cadaver specimens. The position, source and the point of origin of the profunda and its circumflex branches were studied and compared with earlier literature. We found that profunda femoris was originated from the posterolateral surface of the common femoral artery with a mean distance of 3.56 cms from the midinguinal point. An absence of profunda femoris was noted in one (5 %) case. Medial circumflex femoral artery (in 40 % on right side and 60 % on left side) originated from the profunda femoris; whereas in 50 % on right and 35 % on left side, it begins from the femoral artery. On the otherhand, the lateral circumflex femoral in 80 % on right and 70 % on left sides sprungs from profunda femoris with 20 % and 25 % from common femoral arteries of right and left limb specimens respectively. Knowledge of variations in profunda femoris and its branches helps surgeons during preoperative clinical evaluation for surgical and interventional revascularization of the ileo-femoral and femoro-popliteal segments, in open canulation of femoral artery for cardiopulmonary bypasss, in radiological interventions for A-V malformations, and in salvage operations for traumatic limb ischemia.

Recognition of an incidental abscess and a hematoma during ultrasound-guided femoral nerve block

Ultrasound guidance for femoral nerve blockade allows visualization of normal and abnormal anatomy. Two cases of femoral nerve blockade under ultrasound guidance are presented where a major perineural pathologic lesion was incidentally revealed. These pathologic lesions, an abscess and a hematoma, resulted in significant adaptations in clinical care and have not been reported previously. We review and discuss incidental pathologic lesions that can be found in the femoral region. Identification of these 2 pathologic lesions facilitated our perioperative management strategies in two separate cases.

Ultrasound guidance for pediatric peripheral nerve blockade

There is an increasing trend in the use of peripheral nerve blockade for postoperative analgesia in children, and the use of ultrasound guidance to perform peripheral nerve blocks is gaining popularity. A thorough knowledge of anatomy will help in performing the appropriate block, and will also aid in better use and understanding of ultrasound guidance. In this article, we briefly review the use of ultrasound guidance to perform common upper and lower extremity and truncal blocks.