Successful Management of Pelvic Fractures 건국대학교 수의과대학 외과학교실, 수의외과학박사 : 윤 헌 영 Yoonh@Missouri.Edu

Let's make it! Successful management of pelvic fractures 건국대학교 수의과대학 외과학교실, 수의외과학박사 : 윤 헌 영 [email protected]

Cause Trauma - automobile accidents Stress fx - the acetabulum of racing greyhounds by repetitive stresses produced by running

Concurrent Injury Chest Diaphragmatic hernia/ Hemothorax & Pneumothorax/ Traumatic myodarditis Abdomen Bladder rupture & Urethra transection (39% of pelvic fx)/ Intestine perforation or devas devascularization/ Liver, kidney, or spleen laceration/ Traumatic hernia Nerve Sciatic and pudendal nerve

Decision-making Process for Pelvic Injury Pelvic trauma

Physical examination Diagnosis Radiography

Treatment

Conservative treatment Surgical intervention

• Weight bearing fx (pubic & ischial fx) • Non-articular fx (Minimal displacement) • Long-standing fx (>2 weeks) • Financial constraints • Complication - Narrowing of the pelvic cannal with obstipation and lameness

Surgical Intervention

Sacro-iliac Acetabular Ilial Ischial Ilial fx Luxation fx acetabularfx tuberosityfx

Reconstruction Bone Pins plate plate & fixation wires Individual fracture Lag repair screw Composite fixation fixation Bone Lag plate screw Lag screw fixation fixation Lag screw fixation fixation

114 www.kaha.or.kr Golden Time Within 5 days after fx Difficulty of repair after 7 to 10 days Initial fibrosis at the fracture lines/ Contraction of the associated muscles

Sacroiliac Fracture-Luxation Traumatic separation of wing of ilium from sacrum without fx into either ilium or sacrum/ 93% associated with pelvic fx Surgical approach Open/ Closed Open Technique Positioning Lateral recumbence/ Sternal recumbence for bilateral approaches Approach Skin: Cranially (over cranial dorsal iliac spine), Caudally (near hip joint) Two periosteal incisions: Lateral edge of ilium (origin of middle gluteal muscle), medial edge of ilium (origin of sacrospinalis muscle) Two subperiosteal elevations: Lateral edge of ilium (caudally, caudal dorsal iliac spine, note: cranial gluteal vessels and nerve), medial edge of ilium (confined lateral to intermediate crests, note: dorsal nerve roots through dorsal sacral foramina) Drilling site Center of sacral body: Line from most dorsal point to most ventral point of sacral wing and 60% distance from dorsal along the line (caudal to notch: cranial sacral wing), or 2mm cranio-dorsal to crescent-shaped articular cartilage (C-shape) (note: spinal canal ventral limit : 45% distance from dorsal along the line) Ilium: Articular prominence palpation on medial side of ilium Stabilization Implants: Two screws (both in sacral body or one in sacral body and the other in sacral wing/ one screw (in sacral body)/ one screw and one IM pin (both in sacral body) (note: sacral body has approximately 1 cm2 screw penetration which should be at least 60% of sacrum width) Drilling and Screwing: Cortical screw in lag fashion 1) Thread hole in sacral body (tap or not?)/ 2) Measuring depth with depth gauge/ 3) Glide hole in ilial wing/ 4) Repeat 2), 2) + 4) = screw length (note: drilling under fluoroscopy, drilling at 90° cranial-caudal-dorsal-ventral) Reduction: Kern bone-holding forceps

www.kaha.or.kr 115 Closed Technique Positioning Lateral recumbence Reduction Manipulation of hemipelvis 1) IM pin (stab incsion) or AO reduction forceps (percutaneously) on tuber ischium/ 2) Traction of femur/ 3)Applying caudal-lateral traction, digital pressure caudally in small dogs/ 4) Assessment of cranial-caudal and dorsal-ventral reduction and slope of pelvis : superimposition of hemipelvis on lateral view Surgical Procedures (under fluoroscopic guidance) 1) Securing pin: Driving Kirschner wire from ilium to caudal sacral body percutaneously/ 2) Marker pin : Placing Kirshner wire on intended position for insertion of screw/ 3) 1 cm skin incision including marker pin hole/ 4) Placing tap sleeve over marker pin/ 5) Removing marker pin/ 6) Tunnel through gluteal muscle until ilium/ 7) Thread hole into ilium and sacrum/ 8) Glide hole into ilium (note: feel change in resistance on penetration of medial cortex of ilium)/ 9) Screw length : From skin to bot tom of sacral hole using Kirschner wire - from skin to ilium using depth gauge (note: screw length is 2-4 mm shorter than measured depth for lag fashion)/ 10) Tapping sacral hole/ 11) Inserting screw/ 12) Removing securing pin

Ilial Fracture Mostly oblique fracture running from cranioventral to dorsocaudal/ Mostly craniomedially displacement of caudal ilial section/ Be careful ! during reduction of fracture (sciatic nerve running along dorsomedial side of ilium from underside of sacrum to ischium)/ Ilial wing (concave) - cranial: thin (not good screw holding power) and caudal to attachment to sacral wing: thick (good screw holding power)/ Ilium exposure - "Gluteal roll-up" procedure from ventral to dorsal Positioning Lateral recumbence Approach Skin: Cranially (center of iliac crest), Caudally (greater trochanter) Muscle: 1) Incision of deep gluteal fascia on the same line as skin/ 2) Incision of intermu scular septum between tensor fasciae latae and middle gluteal muscles from ventral iliac spine to cranial biceps femoris/ 3) Incision of fascia along cranial border of biceps femori s (T-shaped fascial incision)/ 4) Retraction of middle gluteal muscle/ 5) incision or subpe riosteal elevation of origin of middle gluteal muscle, starting at caudal ventral iliac spine and continuing cranially and dorsally/ 6) Sharp dissection between middle gluteal and

116 www.kaha.or.kr sartorius which blend together/7) Ligation and cut of iliolumbar artery and vein/ 8) Incision or subperiosteal elevation of origin of deep gluteal muscle (Some surgeons sacrifice cranial gluteal vessels and nerve) Reduction (Most challenging procedure) Levering: Slip periosteal elevator between two fracture segments → bring caudal section laterally (note: sciatic nerve) Forceps sliding: One point of bone reduction forceps placed on caudo-dorsal part of cran ial segment, the other point placed on cranio-ventral part of caudal segment, fracture re fracture reduction, and second pointed reduction forceps placement Traction: Intact ischium (two Kern bone-holding forceps) - First (ilial wing), Second (ischium or cranial to acetabulum)/ fractured ischium (caudolateral traction of greater trochanter of femur with pointed bone reduction forceps) (note: manipulation of ischium helps both reduction and lateralization of caudal fracture fragment establishing normal width of pelvic canal) Stabilization Bone plate and screws: The most widely used, dynamic compression plate (DCP) or limited contact DCP (LC-DCP), ideally three screws on each side of fracture, and typically two, three or three and two screws enough on each side, and tightening screws (far-far-near-near for best compression, and contouring plate to match the curve of wing using normal opposite wing, and sometimes need to be twisted) (note: distributing stress and less contact area for less effect on vascularity) (note if two screws on cranial segment, penetration of one screw as far medially as possible) Lag screw fixation or pin and wire: Long oblique fracture/ impossible to approach surgical area of wing in heavily muscled dogs, starting from ventral to dorsal (at least two screws), perpendicular to fracture line/ not thick enough neck of wing (small and medium-sized dogs: pin and figure of eight wire) Combination of lag screws, pin, wire, and plate and screw: Comminuted ilial fractures Complication Screw loosening and breakage of bone plates

Acetabular Fracture Surgical repair requirement for all cases except comminuted fracture (note: comminuted fracture - reconstruction primarily, then femoral head and neck osteotomy next)/ Major weight bearing portion: cranial two thirds of acetabulum/ Articular fracture: Perfect anatomical alignment with rigid stabilization to promotebone healing without excessive callus formation, possibility of DJD (decreased range of motion, pain, and lameness)/ Classification: Cranial,

www.kaha.or.kr 117 central, caudal , and comminuted/ Factors increasing difficulty in surgery: Medial wall of acetabulum separates from rest of actabulum (After reduction, femoral head located in pelvic canal), limited surgical area/ Two primary goals of repair: Perfect anatomical alignment and rigid fixation for promoting primary bone healing without excessive callus formation. Positioning Lateral recumbence Approach Skin: Distally (middle of femur), Proximally (between greater trochanter and dorsal midline) Muscle: Incision of gluteal fascia along cranial border of biceps femoris/ Retraction of biceps femoris caudally/ visualization of sciatic nerve (isolation with Penrose rubber drain)/ dissection of origin of tensor fasciae latae muslce from superficial gluteal muscle/ tenotomizing near its insertion on third trochanter/ osteotomy with 45º beneath insertion of middle and deep gluteal muscles/ reflection of middle and deep gluteal muscles dorsomedially/ dissection of deep gluteal muscle from joint capsule using periosteal elevator Reduction Traction: Manipulation of caudal bone segment with Kern bone-holding forceps placed on ischium/ driving pin across fracture to maintain reduction of fracture Forceps sliding: Placement of one point of forceps on either side of fracture line, then closing forceps to compress the fracture line Stabilization Bone plate and screws: Carefully contour plate to avoid loss of reduction during tightening of the screws/ acetabular plate requiring less contouring Lag screw fixation: Long oblique fracture Combination of lag screws, pin, wire, plate and screw, and PMMA: Comminuted ilial fractures

Ilial Acetabular Fracture Marked displacement of hemielvis, resulting in severe narrowing of pelvic canal/ Ilial fracture repair first Positioning Lateral recumbence Approach Skin: Cranially (center of iliac crest), Caudally (distal to greater trochanter) Muscle: Same as acetabular fracture, elevation of middle and deep gluteal muslces from iliac shaft and cranial acetabular area Reduction Traction

118 www.kaha.or.kr Forceps sliding Stabilization Long bone plate and screws for both fracture repair at once: Pre-contouring plate Repair of ilial fracture and acetabular fractures separately

Ischial Tuberosity Fracture Positioning Lateral recumbence Approach Skin: Dorsal to ventral, Centered medial to lateral over obturator foramen Muscle: Incision of subcutaneous tissue along skin incision line to expose semimembranosus, semitendinosus, biceps femoris, and internal obturator muscles/ small incision of attachment of internal obturator muscle to dorsal part of ischium/ small incision of attachment of semimembranosus muscle to caudoventral part of ischium Reduction flexion of stifle and extension of hip to reduce muscle pull on avulsed bone Forceps sliding Stabilization Two lag screws from caudal to cranial: lateral screw (thick aspect of ischium, directed cranially up into ramus), medial screw (thin aspect of ischium) (note: alternatively IM pin for medial aspect)