Amputation of the dog's hind limb

The original article comes from:

Canine Pelvic Limb Amputation
James Howard, DVM, MS, DACVS, The Ohio State University
Kristen French-Kim, DVM, The Ohio State University
Stephen C. Jones, MVB, MS, DACVS-SA, The Ohio State University
Nina R. Kieves, DVM, DACVS-SA, DACVSMR, CCRT, The Ohio State University

Article
last updated: July 2021
Reading time: approx. 10 minutes
Peer Reviewed

discussion

Canine hindlimb amputations are palliative salvage procedures used for end-stage diseases, including complex fractures or chronic complications following previous osteosynthesis, appendicular neoplasms, extensive trauma, chronic non-healing wounds, or appendicular neuropathies (e.g., brachial plexus avulsion ). Some amputations are unavoidable due to the financial constraints of pet owners. However, surgeons should always exhaust all other treatment options before performing an amputation. At the same time, it is important to provide pet owners with comprehensive information about the risks, complications and prognosis for each clinical case.

Amputation at the level of the middle femur (midfemoral amputation) protects the male genitals and offers a good cosmetic result. However, the risk of increased muscle atrophy and pressure sores is greater here. Amputation due to dislocation of the hip joint (coxofemoral joint disarticulation), on the other hand, reduces the risk of later muscle atrophy and also produces an attractive cosmetic result. This procedure produces a predictable result, reduces the risk of pressure ulcer formation, and facilitates postoperative incision management and home care compared to the midfemoral technique.

A complete orthopedic and neurological examination is required before surgery. Dogs that undergo a hindlimb amputation compensate for this with an increased tarsal range of motion in the contralateral hindlimb as well as an increased range of motion in the cervicothoracic and thoracolumbar spine.^(1) It is important to explain to pet owners that although amputations usually have a good prognosis However, an increased body condition score (BCS) is associated with a lower quality of life rating.^(2) This Preoperative surgical procedure varies depending on the size of the patient, but the anatomical reference points to be identified remain identical (see step 1). Pet owners should be informed that large areas of fur will be removed before the operation and that it may take some time for the hair to grow back.

Preoperative antibiotics (e.g., cefazolin [22 mg/kg IV], ampicillin/sulbactam [30 mg/kg IV]) should be routinely administered at the time of induction and every 90 minutes during surgery. However, since standard amputations are considered clean surgical procedures, the postoperative continuation of antibiotics should be critically questioned in order to prevent the development of resistance. In most cases, unless there is obvious pyoderma around the incision area, antibiotics are not necessary postoperatively.

Preoperative epidural anesthesia, intraoperative perineural injections, liposomal encapsulated bupivacaine during wound closure, and/or insertion of a pain catheter into the superficial tissues should be considered. Perioperative analgesia is essential. In addition, intravenous and oral analgesics should be administered for around 10 to 14 days after the operation - depending on the patient's individual level of pain. Injectable opioids (e.g., morphine, methadone, fentanyl) can be administered immediately postoperatively and, after appropriate pain assessment, switched the following day to oral NSAIDs, which are used throughout convalescence.

Routine postoperative restriction of movement and consistent care of the surgical wound, including cold and heat application, are part of the standard protocol. NSAIDs, additional analgesics and anxiolytics are usually prescribed for home care.

Step-by-Step: Leg amputation in dogs

What you need

• Soft tissue surgery set, including Mayo scissors, Metzenbaum scissors, forceps, various clamps and optional curved hemostats (Right-Angle Forceps)
• Electrocautery
• ± Hatt spoon
• Monofilament suture material (size 4-0 to 0, depending on patient size)
• Polydioxanone suture material for vascular ligation, muscle adaptation and deep subcutaneous closure (size 4-0 to 2-0)
• Poliglecapron 25 for superficial subcutaneous closure (size 4-0 to 3-0)
• Non-absorbing, monofilament suture material (e.g. polybutester [4-0])
• Local anesthetic for perineural injections (do not exceed recommended doses)
  • Ropivacaine (0.5% or 0.75%): 1-3 mg/kg (dog), 1-2 mg/kg (cat)
  • Bupivacaine (0.25% or 0.5%): 1-2 mg/kg (dog), 1 mg/kg (cat)
• Syringes and cannulas for perineural injections (syringe volume depending on recommended dose; a 25 G cannula is recommended for perineural injections)
• 4x4 or 3x3 gauze and laparotomy sponges to stop bleeding

Step 1

Shave the fur from the level of the navel, dorsally 2 to 5 cm beyond the dorsal midline, ventrally 5 cm beyond the ventral midline, in the entire groin and abdominal area, and circularly around the affected hind limb up to the hock. Also remove fur from the perineal area and the base of the tail. If there is soft stool or diarrhea, an anal pursestring suture can be placed. Wrap the distal part of the limb (below the ankle) in a sterile manner and place the patient in a lateral position with the hind limb to be operated on top. The limb is then covered in a sterile manner in the operating area.

step 2

Mark the planned incision lines so that sufficient skin is available for later wound closure. The lateral incision (dashed line) begins at the level of the cranial flank fold and runs in a gentle curve distally to about half of the femur before ending at the caudal flank fold near the ischial tuberosity ) ends. The medial incision (continuous line) is mirrored, but slightly more proximal.

step 3

Perform medial dissection by abducting the limb. Use curved hemostats (Right-Angle Forceps) to open the subcutaneous tissue (subcutaneous tissue) and the underlying deep thigh fascia (fascia femoris) through sharp and blunt dissection. Palpate the medial area of ​​the thigh to locate the short, tight muscle band of the pectineus muscle. This palpable point points the way to the femoral triangle (Trigonum femorale).

Author's Note
The femoral triangle carries the femoral artery, femoral vein (Figure A; solid arrow), and the saphenous branch of the femoral nerve to the hind limb. When dissecting the vessels, blunt dissection should be performed using curved clamps in the longitudinal direction of the vessels (Figure B) to avoid accidental vessel rupture or injury.

The boundaries of the femoral triangle are:

• Cranial : Caudal part of the sartorius muscle
• Caudal : M. pectineus (easily palpable to find the triangle; Figure A, dashed arrow)
• Lateral : M. vastus medialis, M. pectineus and M. iliopsoas
• Medial : External sheet of the abdominal muscles (M. obliquus externus abdominis)

Step 4

Dissect out the femoral artery, femoral vein (Figure A), and the saphenous branch of the femoral nerve. Each vessel is ligated three times. Place a transfixation and a circular ligature on the side of the vessel remaining toward the patient and then another circular ligature on the side that will be removed with the severed limb to prevent backbleeding. Divide the vessel between the transfixing suture, which remains on the patient, and the circular suture, which prevents backbleeding (Figure B).

To perform a local nerve block, insert the cannula into the perineural sheath and inject a small amount of ropivacaine or bupivacaine. A small “bubble” forms. Wait 3 minutes and then cut the nerve distal to the injection site.

Author's Note
Larger arteries and veins are always treated with a transfixing and two circular ligatures, especially in medium to large dogs. In smaller dogs and cats, arteries and veins can be ligated using three circular ligatures. Two ligatures always remain on the patient's side; one ligature goes with the amputated limb to prevent bleeding back.

Step 5

Work your way cranially and caudally to the two bellies of the sartorius muscle (cranial and caudal; solid arrows), the pectineus muscle (dashed arrow; can be divided at the origin, in the muscle belly or at the insertion), the M. adductor (Ad) and the M. gracilis (Gr) in the middle of the femur. Once the medial circumflex femoris artery and medial circumflex femoris vein or their deep branches* are encountered, ligate them as described in step 4. (The semimembranosus [Sm] muscle is marked for orientation.)

Palpate the lesser trochanter of the femur and cut the iliopsoas (Ili) muscle either in the muscle belly or at its insertion.

Author's Note
Only the extrinsic muscles of the hind limb (i.e., those that connect the limb to the pelvis) need to be severed. Over-dissection of the quadriceps femoris muscles can prolong operative time and increase the risk of complications.

The femoral nerve passes through the iliopsoas muscle before leaving it and entering the rectus femoris and vastus medialis muscles. The femoral nerve can be blocked with ropivacaine or bupivacaine and then severed.

*The vascular bundle lies caudal to the femoral artery and vein, medial to the pectineus muscle and lateral to the iliopsoas muscle (Ili).

Step 6

Palpate the medial joint capsule (dashed arrow) and incise sharply along the border of the acetabulum. Once the joint capsule is opened, sever the femoral capitis ossis ligament using a scalpel, Mayo scissors, or Hatt spoon. (The iliopsoas [Ili] muscle is marked with the solid arrow for orientation.)

Author's note
The limb should be moved passively (range of motion) to accurately identify the hip joint and specifically open the joint capsule.

Step 7

Adduct the limb to expose the lateral muscle attachments. Sever the tensor fasciae latae (TFL) at the distal portion and the associated fascia lata (FL) at the level of the middle of the femur. Also in this dissection plane, the biceps femoris (BF) and caudal crural abductor (CCA) muscles are divided near the middle of the femur. The sciatic nerve should be blocked with a local anesthetic before it is transected, as neuropathic pain can cause unnecessary stress to the animal postoperatively.

Author's note
The biceps femoris muscle arises from the ventrocaudal portion of the sacrotuberous ligament and from the sciatic tuberosity. The proximal part of the severed muscle belly can be folded dorsally, which allows dissection and separation of the muscles. semitendinosus (St) and semimembranosus (Sm) facilitated.

Step 8

While the dorsal folding of the biceps femoris muscle exposes the region around the greater trochanter and tertius on the femur (which improves the view of the gluteus superficialis, medius, profundus and the deeper piriformis muscle), you separate each of the mentioned muscles closely their insertion site.

Fold the superficial gluteus and piriformis muscles dorsally and carefully dissect the underlying fascia to expose the caudal gluteal artery, caudal gluteal vein, and sciatic nerve (already severed), which are close together. Ligate the gluteal caudal artery and vein separately using three ligatures.

Step 9

At the caudal edge of the hip joint, locate the Mm. gemelli (Ge); their muscle bellies are divided by the tendon of the obturator internus (IO) muscle. Separate the mm. gemelli in the muscle belly and the tendon of the obturator internus muscle.

Split the muscle bellies of the muscles. gemelli dorsally and ventrally to expose the underlying obturator externus muscle, which you then also cut in the muscle belly. At the same time, only the rectus femoris muscle, the only part of the quadriceps muscles in contact with the pelvis, is separated.

At the dorsal part of the acetabulum, incise the remaining part of the joint capsule (curved arrow) including the small articularis coxae muscle. Ligate the branch of the lateral circumflex femoral artery.

On the caudal portion of the limb, isolate the abductor cruris caudalis muscle (the scissors are below the muscle in the picture), and separate it in the middle of the muscle belly.

Step 10

Identify the iliopsoas muscle by its close proximity to the main trunk of the femoral nerve. If the saphenous branch of the femoral nerve has not yet been divided, now separate the main trunk of the femoral nerve. To release the cranial and ventromedial portions of the limb, abduct the limb, separate any remaining iliopsoas muscle attachments, and ligate any remaining branches of the A./V. circumflexa femoris medialis.

Caudal to the iliopsoas muscle, isolate the muscles. adductor longus and quadratus femoris and separate both in the middle of the muscle belly.

Complete the ventral incision on the joint capsule. Use monopolar electrocautery to control bleeding.

Gently abduct the limb to expose the femoral head. Sever any remnants of the ligamentum capitis ossis femoris to perform complete dislocation in the hip joint (coxofemoral disarticulation). Remove the limb from the body.

Author's Note
Smaller branches of the medial circumflex femoral artery run in close proximity to the ventral joint capsule.

Step 11

Before closing the wound, examine the surgical area for possible bleeding and plan measures against dead space. Flush the surgical field with warm saline to minimize the risk of postoperative infection.

Step 12

Start with deep muscle closure. Bring the muscle bellies together so that the acetabulum and the transection sites of the A., V. and nerves are covered. Use a running or interrupted suture technique (arrows) with absorbable suture material (size 3-0 to 0 depending on patient size).

Step 13

Close the subcutaneous layer in the usual manner. If desired, a pain soaker catheter can be placed in the superficial tissues for postoperative administration of local analgesics - but not directly into the incision area. Triangular excess skin (so-called “dog ears”) often develops at the edge of the wound. If there is excessive excess skin, this skin can be removed and closed routinely. Minor dog ears can be corrected using various geometric techniques, including placing an apical skin suture, removing the excess skin in a fusiform extension of the incision, or a triangular excision at the incision.

Author's note
During the entire wound closure, care must always be taken to ensure that there is enough skin for a tension-free closure. Excess skin should be removed to minimize dead spaces.

Step 14

Carry out the skin or intradermal closure - either using a continuous or interrupted technique (suture strength 4-0 to 3-0, depending on the patient size).

Author's Note
Staples are not recommended due to potential pain and increased inflammatory response, but may be considered for longer incisions in large dogs.

If you have any further questions, please feel free to contact our chief surgeon Susanne Arndt .

Summary of leg amputation in dogs

Canine Leg Amputation: A surgical procedure for dogs with serious hind limb disorders. It offers a palliative solution for fractures, neoplasms, neuropathies and more. for 40 seconds

Leg amputation in dogs is a frequently discussed procedure. A dog's leg amputation is often necessary if there are serious injuries. When a dog has a leg amputation, the affected leg is surgically removed. A dog's leg amputation allows the animal to adapt to life on three legs despite limitations.

Veterinarians emphasize that canine leg amputation is a palliative procedure, but canine leg amputation is often recommended due to cancer or trauma. Before a dog's leg is amputated, possible complications must be considered. Special care is important after a dog has had a leg amputated. Recovery from a canine leg amputation involves pain management, rehabilitation exercises, and close observation.

Although a dog leg amputation often goes well, a dog leg amputation can be emotionally stressful for pet owners. The long-term chances of success after a leg amputation in dogs are still high. A canine leg amputation allows many dogs to continue to lead an active life. For financial reasons, a dog's leg amputation may be necessary.

In any case, amputation of a dog's leg should only be considered as a last resort. After a comprehensive examination, amputation of the dog's leg is sometimes considered due to infections. A leg amputation in dogs also requires careful aftercare. Despite a dog having a leg amputated, many animals remain mobile.

Amputation of a dog's leg is not always the only option, but it is often the most sensible one. The course of a leg amputation in dogs can vary from person to person. A dog's leg amputation requires precise cost planning. Ultimately, a dog's leg amputation can significantly improve the animal's life.

References & further reading

1. 
   Hogy SM, Worley DR, Jarvis SL, Hill AE, Reiser RF 2nd, Haussler KK. Kinematic and kinetic analysis of dogs during trotting after amputation of a pelvic limb. At J Vet Res . 2013;74(9):1164-1171.
2. Dickerson VM, Coleman KD, Ogawa M, et al. Outcomes of dogs undergoing limb amputation, owner satisfaction with limb amputation procedures, and owner perceptions regarding postsurgical adaptation: 64 cases (2005–2012). J Am Vet Med Assoc . 2015;247(7):786-792.
3. Hermanson JW, de Lahunta A, Evans HE. Miller and Evans' Anatomy of the Dog . 5th ed. Elsevier; 2020.
4. Johnston SA, Tobias KM, eds. Veterinary Surgery: Small Animals . 2nd ed. Elsevier; 2018.

About the authors

James Howard, DVM, MS, DACVS
The Ohio State University
James Howard, DVM, MS, DACVS, is an assistant professor of soft tissue surgery at The Ohio State University, where he also completed his DVM degree and surgical residency. He also completed a rotation in internal medicine and surgery at the University of Tennessee. His research interests include hepatobiliary and gastrointestinal surgery and endocrinopathies. Currently, Dr. Howard with minimally invasive diagnostic procedures, pharmacokinetic and pharmacodynamic questions as well as methods for hepatobiliary sample collection.

Kristen French-Kim, DVM
The Ohio State University
Kristen French-Kim, DVM, received her DVM degree in May 2021 from The Ohio State University. She has a research background in immunology, vaccine research and anatomical pathology and is pursuing a career in small animal surgery.

Stephen C. Jones, MVB, MS, DACVS-SA
The Ohio State University
Stephen Jones, MVB, MS, DACVS-SA, is an assistant professor of small animal orthopedics at The Ohio State University. Dr. Jones studied veterinary medicine at University College Dublin in Ireland. He then completed both a surgical rotation and specialty internship at the Hollywood Animal Hospital in Hollywood, Florida, as well as a combined residency in small animal surgery and a Master of Science at the University of Florida. Dr. Jones has authored and published numerous scholarly articles, book chapters, and abstracts and lectures worldwide. His special interests include minimally invasive fracture care, medical and surgical treatment of joint diseases, arthroscopy, and surgical management of limb deformities.

Nina R. Kieves, DVM, DACVS-SA, DACVSMR, CCRT
The Ohio State University Nina
R. Kieves, DVM, DACVS-SA, DACVSMR, CCRT, is an associate professor of small animal orthopedics and director of sports medicine and rehabilitation services at Ohio State University. She received her DVM degree from the University of Minnesota, completed a residency in small animal surgery at Iowa State University and a fellowship in sports medicine at Colorado State University. Dr. Kieves' research focuses on sports medicine and rehabilitation as well as surgical therapy using minimally invasive techniques.