Limb Anatomy and Surgical Approaches




© Springer-Verlag France 2015
Cyril Mauffrey and David J. Hak (eds.)Passport for the Orthopedic Boards and FRCS Examination10.1007/978-2-8178-0475-0_2


Lower Limb Anatomy and Surgical Approaches



Jason M. McKean1  , John Riehl2   and David Seligson3  


(1)
Department of Orthopaedics, Lincoln Medical Center, Bronx, USA

(2)
Department of Orthopaedics, Andrews Institute for Orthopaedics, Pensacola, USA

(3)
Department of Orthopaedics, University of Louisville Hospital, Louisville, KY, USA

 



 

Jason M. McKean (Corresponding author)

Email: jasonmckean@gmail.com


 

John Riehl

Email: jtriehl@hotmail.com


 

David Seligson

Email: seligson@louisville.edu



1 Pelvis






  • Approach to the anterior pelvic ring



    • Indications



      • Access to pubic symphysis and superior pubic ramus


    • Superficial dissection



      • Internervous plane



        • No internervous plane


        • Rectus abdominis muscles receive segmental innervation so they are not denervated


      • Incise through subcutaneous fat down to rectus sheath


      • Ligate superficial epigastric arteries and veins


      • Split the rectus muscles vertically along the midline raphe


    • Deep dissection



      • Develop the space of Retzius with blunt dissection


      • Subperiosteally dissect superior pubic ramus to reveal the symphysis and pubic crest


    • Dangers



      • Bladder



        • Mobilization of space of Retzius (anterior to bladder and posterior to pubic symphysis) may be dangerous if there are adhesions present


      • Corona mortis



        • Anastomosis between external iliac and obturator vessels


        • These vessels vary in size but are fairly consistently present


        • Ligate as they course over the lateral third of the superior pubic ramus


  • Anterior approach to sacroiliac (SI) joint



    • Indications



      • Access to anterior sacroiliac joint


    • Superficial dissection



      • Internervous plane



        • No internervous plane


      • Incision in line with iliac crest and continues anteromedially beyond anterior superior iliac spine


      • Incise through subcutaneous fat down to iliac crest


      • The deep fascia can be elevated off the crest with subperiosteal elevation along the inner table of the pelvis, or an osteotomy of the iliac crest can be performed for bony healing after closure


    • Deep dissection



      • Raise the iliacus muscle subperiosteally off the inner wall of the ilium heading medially until the sacroiliac joint is exposed



        • Hip flexion can aid in this dissection


    • Dangers



      • Lateral cutaneous nerve of the thigh



        • If osteotomy is used, then nerve may have to be sacrificed for exposure which will result in numbness of the lateral thigh


      • Sacral nerve roots



        • At risk where they emerge from the sacral foramina


        • Dissection should stop at approximately 1 cm from the anterior edge of the SI joint


        • Care must be taken with retractor positioning and positioning plates medially


2 Hip and Acetabulum






  • Anterior (Smith-Petersen) approach to the hip



    • Indications



      • Access to anterior hip joint


    • Superficial dissection



      • Internervous plane



        • Sartorius (femoral nerve) and tensor fasciae latae (superior gluteal nerve)


      • Identify the plane between the sartorius and the tensor fasciae latae 2–3 cm below the anterior superior iliac spine


      • Dissect through subcutaneous fat along the interval (alternatively can dissect through fascia of tensor fasciae latae to avoid lateral femoral cutaneous nerve)



        • Take care to preserve the lateral femoral cutaneous nerve of the thigh


        • The nerve runs over the fascia of the sartorius


      • Incise deep fascia on medial aspect of tensor fasciae latae


      • Retract the tensor fasciae latae posteriorly and inferiorly and the sartorius superiorly and medially



        • Release the tensor fasciae latae from its origin (lateral anterior iliac crest) as needed to gain exposure


      • Ligate or cauterize the large ascending branch of the lateral femoral circumflex artery that crosses inferior to the anterior superior iliac spine


    • Deep dissection



      • Internervous plane



        • Rectus femoris (femoral nerve) and gluteus medius (superior gluteal nerve)


      • The rectus femoris has two heads



        • One originates from anterior inferior iliac spine, and the other originates from the superior lip of the acetabulum/anterior capsule of hip joint


      • Detach the rectus femoris from its origins and retract medially to expose the hip capsule


      • The iliopsoas is found in the inferomedial aspect of the wound and inserts into the lesser trochanter of the femur



        • Retract medially


      • Adduct and externally rotate the hip to put the capsule on stretch


      • Incise the capsule to expose the hip joint


    • Dangers



      • Lateral cutaneous nerve of the thigh



        • Passes the sartorius muscle approximately 2.5 cm distal to the anterior superior iliac spine


        • Cutting the nerve can cause a painful neuroma


      • Femoral nerve



        • Courses directly anterior to the hip joint within the femoral triangle (superiorly, inguinal ligament; laterally, sartorius; medially, adductor magnus)


        • Nerve is medial to rectus and not in field


        • If anatomy becomes unclear, feel for the femoral pulse which is medial to the nerve and well medial to dissection plane


      • Ascending branch of lateral femoral circumflex artery



        • Ligate as it crosses operative field proximally between tensor fasciae latae and sartorius muscles


  • Anterolateral (Watson-Jones) approach to the hip



    • Indications



      • Access to anterolateral hip joint


    • Superficial dissection



      • Internervous plane



        • No true internervous plane


        • Gluteus medius and the tensor fasciae latae are both innervated by the superior gluteal nerve



          • Avoid extremely proximal dissection between these two muscles, and the nerve will remain intact


      • Incise subcutaneous fat until reaching deep fascia of the thigh over the greater trochanter


      • Incise the fascia lata and the bursa over the greater trochanter


      • Incise the fascia lata in line with its fibers heading toward the anterior superior iliac spine


      • Extend fascial incision distally to expose the vastus lateralis


      • Reflect the fascial flap anteriorly to better expose the interval between the tensor fasciae latae and the gluteus medius



        • Branches of the superior gluteal artery are found in this interval and must be ligated or cauterized


    • Deep dissection



      • The abductor mechanism needs to be retracted to gain better exposure of the hip joint



        • The greater trochanter can be osteotomized and reflected superiorly and repaired


        • The anterior one third of the tendinous insertion of the gluteus medius can be partially released from its insertion on the greater trochanter


      • Retract the gluteus medius and minimus laterally and superiorly


      • To put the capsule on stretch, fully externally rotate and adduct the hip


      • Elevate the vastus lateralis off the vastus lateralis ridge to expose the anterior aspect of the joint capsule


      • Bluntly clear the anterior aspect of the hip capsule and detach the reflected head of the rectus femoris off the anterior lip of the acetabulum



        • Partially flexing the hip will make this easier


      • Incise the capsule and the hip joint is exposed


    • Dangers



      • Femoral nerve



        • Courses directly anterior to the hip joint within the femoral triangle (superiorly, inguinal ligament; laterally, sartorius; medially, adductor magnus)


        • The most common problem is compression neuropraxia secondary to overzealous medial retracting


        • If anatomy becomes unclear, feel for the femoral pulse which is medial to the nerve and well medial to dissection plane


      • Femoral artery and vein



        • At risk with aberrant retractor placement


  • Lateral (Hardinge) approach to the hip



    • Indications



      • Access to anterior hip joint


    • Superficial dissection



      • Internervous plane



        • There is no internervous plane


      • Dissect through subcutaneous fat down to fascia over the greater trochanter of the proximal femur


      • Incise the deep fascia in line with the incision and retract the edges of the fascia to pull the tensor fasciae latae anteriorly and the gluteus maximus posteriorly


      • The gluteus medius and the vastus lateralis are now exposed, and both attach to the greater trochanter


    • Deep dissection



      • Split the fibers of the gluteus medius longitudinally starting at the middle third of the greater trochanter



        • Put a stay suture in the muscle fibers to prevent dissection of greater than 3 cm proximal to the greater trochanter so there is no denervation of the superior gluteal nerve


      • Split fibers of the vastus lateralis in the same line as the gluteus medius


      • Form an anterior flap consisting of the gluteus medius (with some underlying gluteus minimus) and the vastus lateralis


      • The proximal and distal muscle units will be connected by the tendinous region that is elevated off the greater trochanter


      • As this anterior flap is elevated and retracted medially to expose the hip capsule, the gluteus minimus insertion to the greater trochanter will need to be released


      • The capsule is now exposed and a capsulotomy can be performed


    • Dangers



      • Superior gluteal nerve



        • Courses between the gluteus medius and minimus 3–5 cm proximal to the greater trochanter


        • A stay suture can help prevent unintended proximal dissection and potential nerve injury


      • Femoral nerve



        • Courses directly anterior to the hip joint within the femoral triangle (superiorly, inguinal ligament; laterally, sartorius; medially, adductor magnus)


        • At risk for inappropriately placed retractors


      • Femoral artery and vein



        • At risk with aberrant retractor placement


      • Transverse branch of the lateral femoral circumflex artery



        • Must be cauterized during approach to allow mobilization of vastus lateralis


  • Ilioinguinal approach to the acetabulum



    • Indications



      • Access to anterior column of acetabulum


    • Superficial dissection



      • Internervous plane



        • There is no internervous plane


      • Dissect down to aponeurosis of external oblique muscle along the iliac crest


      • The lateral cutaneous nerve of the thigh will be exposed in the lateral aspect of this dissection, and often it needs to be transected


      • Incise the aponeurosis of the external oblique from the superficial inguinal ring to the anterior superior iliac spine



        • This exposes the spermatic cord in the male and the round ligament in the female


        • Tag these structures when identified


      • Divide the anterior rectus sheath medially to expose the underlying rectus abdominis muscle


      • Dissect the iliacus muscle off the iliac fossa exposing the anterior iliosacral joint and pelvic brim


    • Deep dissection



      • Release the rectus abdominis muscle off the insertion of the pubic symphysis, leaving a cuff for later repair


      • Bluntly open the space of Retzius between the bladder and pubic symphysis


      • Divide the internal oblique muscle and the transverse abdominis muscles both medially and laterally to the deep inguinal ring



        • Together these two muscles form the posterior wall of the inguinal canal


        • Ligate the inferior epigastric vessels that arise near the deep inguinal ring


      • The extraperitoneal fat is now exposed and should be bluntly swept superiorly to reveal the femoral vessels, the femoral nerve, and the tendon of the iliopsoas



        • The iliopectineal fascia separates the iliopsoas and femoral nerve from the femoral artery and vein


      • Identify the anterior aspect of the femoral vessels and the lymphatics in the midportion of the incision


      • Place one sling around the femoral sheath and another around the iliopsoas with the femoral nerve lying superficial to it


      • This creates three “windows”



        • Lateral window: lateral aspect of wound to iliopsoas (iliopectineal fascia)



          • Provides access to the iliac wing, the quadrilateral plate, and anterior sacroiliac joint


        • Middle window: between the external iliac vessels and the iliopsoas (iliopectineal fascia)



          • Provides access to the pelvic brim, the quadrilateral plate, and the lateral aspect of the superior pubic ramus


        • Medial window: medial aspect of wound to external iliac vessels



          • Provides direct access to pubic rami


    • Dangers



      • Femoral nerve



        • Courses beneath the inguinal canal on the iliopsoas



          • Stretching the nerve with aggressive retraction can lead to postoperative quadriceps weakening


      • Lateral cutaneous nerve of the thigh



        • Often need to be sacrificed


      • Femoral artery and vein



        • These should be kept together in the femoral sheath as opposed to dissecting them out separately


      • Inferior epigastric vessels



        • Should be ligated to provide access to deeper structures


      • Spermatic cord



        • The vas deferens and the testicular artery are found within the cord


        • Avoid overtightening around the cord during closure to prevent ischemic damage to testicle


  • Modified Stoppa approach to the acetabulum



    • Indications



      • Access to



        • Quadrilateral plate


        • Superior pubic ramus


        • Ilium


        • Medial aspect of posterior column


        • Sciatic buttress


        • Anterior sacroiliac joint


    • Superficial dissection



      • Internervous plane



        • There is no internervous plane


      • Dissect through subcutaneous fascia down to rectus fascia and incise vertically in midline


      • Incise transversalis fascia superior to pubic symphysis


      • Bluntly open the space of Retzius and pack with sponges to protect the bladder


    • Deep dissection



      • Using subperiosteal elevation, expose the superior pubic ramus, posterior surface of the ramus, pelvic brim, and internal iliac fossa



        • Protect the external iliac vessels during this dissection


      • The corona mortis (anastomosis between the external iliac vessels and the obturator vessels) will be encountered as the artery and vein course over the superior pubic ramus toward the obturator foramen



        • Ligate these vessels to gain exposure along the pelvic brim and quadrilateral surface


      • Detach the iliopectineal fascia over the anterior column to gain additional exposure along the pelvic brim


      • Continue dissection toward anterior sacroiliac joint to expose entire pelvic brim


      • Expose the quadrilateral surface and posterior column while protecting the obturator neurovascular bundle


    • Dangers

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Sep 18, 2016 | Posted by in ORTHOPEDIC | Comments Off on Limb Anatomy and Surgical Approaches

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