We aimed to quantify the relative contributions of the medial
femoral circumflex artery (MFCA) and lateral femoral circumflex
artery (LFCA) to the arterial supply of the head and neck of the
femur. We acquired ten cadaveric pelvises. In each of these, one hip
was randomly assigned as experimental and the other as a matched
control. The MFCA and LFCA were cannulated bilaterally. The hips
were designated LFCA-experimental or MFCA-experimental and underwent
quantitative MRI using a 2 mm slice thickness before and after injection
of MRI-contrast diluted 3:1 with saline (15 ml Gd-DTPA) into either
the LFCA or MFCA. The contralateral control hips had 15 ml of contrast
solution injected into the root of each artery. Next, the MFCA and
LFCA were injected with a mixture of polyurethane and barium sulfate
(33%) and their extra-and intra-arterial course identified by CT
imaging and dissection.Aims
Materials and Methods
This study investigates and defines the topographic
anatomy of the medial femoral circumflex artery (MFCA) terminal
branches supplying the femoral head (FH). Gross dissection of 14
fresh–frozen cadaveric hips was undertaken to determine the extra
and intracapsular course of the MFCA’s terminal branches. A constant
branch arising from the transverse MFCA (inferior retinacular artery;
IRA) penetrates the capsule at the level of the anteroinferior neck,
then courses obliquely within the fibrous prolongation of the capsule
wall (inferior retinacula of Weitbrecht), elevated from the neck,
to the posteroinferior femoral head–neck junction. This vessel has
a mean of five (three to nine) terminal branches, of which the majority
penetrate posteriorly. Branches from the ascending MFCA entered
the femoral capsular attachment posteriorly, running deep to the
synovium, through the neck, and terminating in two branches. The
deep MFCA penetrates the posterosuperior femoral capsular. Once
intracapsular, it divides into a mean of six (four to nine) terminal
branches running deep to the synovium, within the superior retinacula
of Weitbrecht of which 80% are posterior. Our study defines the
exact anatomical location of the vessels, arising from the MFCA
and supplying the FH. The IRA is in an elevated position from the
femoral neck and may be protected from injury during fracture of
the femoral neck. We present vascular ‘danger zones’ that may help
avoid iatrogenic vascular injury during surgical interventions about
the hip. Cite this article:
A surgical hip dislocation provides circumferential access to the femoral head and is essential in the treatment pediatric and adult hip disease. Iatrogenic injury to the femoral head blood supply during a surgical may result in the osteonecrosis of the femoral head. In order to reduce vessel injury and incidence of AVN, the Greater Trochanteric Osteotomy (GTO) was developed and popularized by Ganz. The downside of this approach is the increased morbidity associated with the GTO including non-union in 8% and painful hardware requiring removal in 20% of patients. (reference) Recent studies performed at our institution have mapped the extra-osseous course of the medial femoral circumflex artery and provide surgical guidelines for a vessel preserving posterolateral approach. In this cadaveric model using Gadolinium enhanced MRI, we investigate whether standardized alterations in the postero-lateral surgical approach may reliably preserve femoral head vascularity during a posterior surgical hip dislocation In 8 cadaveric specimens the senior author (ES) performed a surgical hip dislocation through the posterolateral approach with surgical modifications designed to protect the superior and inferior retinacular arteries. In every specimen the same surgical alterations were made using a ruler: the Quadratus Femoris myotomy occurred 2.5 cm off its trochanteric insertion, the piriformis tenotomy occurred at its insertion and extended obliquely leaving a 2 cm cuff of conjoin tendon (inferior gemellus), and the Obturator Externus (OE) was myotomized 2 cm off its trochanteric insertion. (Figure 1) For the capsulotomy, the incision started on the posterior femoral neck directly beneath the cut obturator externus tendon and extending posteriorly to the acetabulum. Superior and inferior extensions of the capsulotomy ran parallel to the acetabular rim creating a T-shaped capsulotomy. After the surgical dislocation was complete, the medial femoral circumflex artery (MFCA) was cannulated and Gadolinium-enhanced MRI performed in order to assess intra-osseous femoral head perfusion and compared to the gadolinium femoral head perfusion of the contra-lateral hip as a non-operative control. Gross-dissection after polyurethane latex injection in the cannulated MFCA was performed to validate MRI findings and to assess for vessel integrity after the surgical dislocation.Introduction:
Methods:
Precise knowledge of the Femoral Head (FH) arterial supply is critical to avoid FH avascular necrosis following open and arthroscopic intra-capsular surgical procedures about the hip. The Medial Femoral Circumflex Artery (MFCA) provides the primary FH vascular contribution. Distribution of vascular foramina at the Femoral Head-Neck Junction (FHNJ) has been reported previously using an imaginary clock face. However, no quantitative information exists on the precise Capsular Insertion (CI) and intra-capsular course of the MFCA Terminal Branches (TBs) supplying the FH. This study seeks to determine the precise anatomic location of the MFCA's TBs supplying the FH, in order to help avoid iatrogenic vascular damage during surgical intervention. In 14 fresh-frozen cadaveric hips (9 left and 5 right), we cannulated the MFCA and injected a polyurethane compound. Using a posterior approach, careful dissection of the MFCA allowed us to identify and document the extra- and intra-capsular course of the TBs penetrating the FHNJ and supplying the FH. An H-type capsulotomy provided joint access while preserving the intracapsular Retinaculum of Weitbrecht (RW), followed by circumferential capsulotomy at the acetabular margin exposing the FH. The dome of the FH was osteotomized 5 mm proximal to the Articular Border (AB) providing a flat surface for our 360° scale. Right-side equivalents were used for data processing.Introduction
Methods
The debate regarding the importance of preserving the blood supply to the femoral head (FH) and neck during hip resurfacing arthroplasty (HRA) is ongoing. Several surgeons continue to advocate for the preservation of the blood supply to the resurfaced heads for both the current HRA techniques and more biologic approaches for FH resurfacing. Despite alternative blood-preserving approaches for HRA, many surgeons continue to use the posterior approach (PA) due to personal preference and comfort. It is commonly accepted that the PA inevitably damages the deep branch of the medial femoral circumflex artery (MFCA). This study seeks to evaluate and measure the anatomical course of the ascending and deep branch of the MFCA to better describe the area in danger during the posterior approach. In 20 fresh-frozen cadaveric hips, we cannulated the MFCA and injected a urethane compound. The Kocher-Langenbeck approach was used in all specimens. The deep branch of the MFCA was identified at the proximal border of the QF and measurements were taken. The QF was incised medially and elevated laterally, maintaining the relationship of the ascending branch and QF, and distances from the lesser trochanter were measured. The deep branch was dissected and followed to its capsular insertion to assess the course and relation to the obturatur externus (OE) tendon and the conjoint tendon (CT) of the short external rotators.Introduction
Methods
It has previously been suggested that among unstable
ankle fractures, the presence of a malleolar fracture is associated
with a worse outcome than a corresponding ligamentous injury. However,
previous studies have included heterogeneous groups of injury. The
purpose of this study was to determine whether any specific pattern of
bony and/or ligamentous injury among a series of supination-external
rotation type IV (SER IV) ankle fractures treated with anatomical
fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures
with a follow-up of one year. Pre-operative radiographs and MRIs
were undertaken to characterise precisely the pattern of injury.
Operative treatment included fixation of all malleolar fractures.
Post-operative CT was used to assess reduction. The primary and
secondary outcome measures were the Foot and Ankle Outcome Score
(FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four
possible SER IV fracture pattern groups with regard to the FAOS
or range of movement. In this population of strictly defined SER
IV ankle injuries, the presence of a malleolar fracture was not
associated with a significantly worse clinical outcome than its
ligamentous injury counterpart. Other factors inherent to the injury
and treatment may play a more important role in predicting outcome.
We have examined the accuracy of reduction and the functional outcomes in elderly patients with surgically treated acetabular fractures, based on assessment of plain radiographs and CT scans. There were 45 patients with such a fracture with a mean age of 67 years (59 to 82) at the time of surgery. All patients completed SF-36 questionnaires to determine the functional outcome at a mean follow-up of 72.4 months (24 to 188). All had radiographs and a CT scan within one week of surgery. The reduction was categorised as ‘anatomical’, ‘imperfect’, or ‘poor’. Radiographs classified 26 patients (58%) as anatomical,13 (29%) as imperfect and six (13%) as poor. The maximum displacement on CT showed none as anatomical, 23 (51%) as imperfect and 22 (49%) as poor, but this was not always at the weight-bearing dome. SF-36 scores showed functional outcomes comparable with those of the general elderly population, with no correlation with the radiological reduction. Perfect anatomical reduction is not necessary to attain a good functional outcome in acetabular fractures in the elderly.
The inferior gluteal artery is described in standard anatomy textbooks as contributing to the blood supply of the hip through an anastomosis with the medial femoral circumflex artery. The site(s) of the anastomosis has not been described previously. We undertook an injection study to define the anastomotic connections between these two arteries and to determine whether the inferior gluteal artery could supply the lateral epiphyseal arteries alone. From eight fresh-frozen cadaver pelvic specimens we were able to inject the vessels in 14 hips with latex moulding compound through either the medial femoral circumflex artery or the inferior gluteal artery. Injected vessels around the hip were then carefully exposed and documented photographically. In seven of the eight specimens a clear anastomosis was shown between the two arteries adjacent to the tendon of obturator externus. The terminal vessel arising from this anastomosis was noted to pass directly beneath the posterior capsule of the hip before ascending the superior aspect of the femoral neck and terminating in the lateral epiphyseal vessels. At no point was the terminal vessel found between the capsule and the conjoined tendon. The medial femoral circumflex artery receives a direct supply from the inferior gluteal artery immediately before passing beneath the capsule of the hip. Detailed knowledge of this anatomy may help to explain the development of avascular necrosis after hip trauma, as well as to allow additional safe surgical exposure of the femoral neck and head.
