Lecture 5-VCS 80630-Fall 2023-- Amputation and other salvage procedures.pdf

AMPUTATION AND OTHER SALVAGE PROCEDURES Dr. Sarah Malek VCS 80630- Small Animal Surgery Fall 2023 LEARNING OBJECTIVES • List types of and indications for fore and hind limb amputations • List complications and limitations of limb salvage procedures in dogs and cats • Outline indications and genera...

AMPUTATION AND OTHER SALVAGE PROCEDURES Dr. Sarah Malek VCS 80630- Small Animal Surgery Fall 2023 LEARNING OBJECTIVES • List types of and indications for fore and hind limb amputations • List complications and limitations of limb salvage procedures in dogs and cats • Outline indications and general principles of toe and tail amputation • Describe indications, side effects, techniques, welfare considerations and alternatives for decalw in cats • Describe the difference between arthrodesis and ankylosis • Outline types of arthrodesis and principles of arthrodesis • List the indications for joint replacement OUTLINE • Amputation • Arthrodesis • Limb sparing procedures • Joint replacement AMPUTATION Removal of an appendage or portion of an appendage Forelimb • Forequarter • Scapulohumeral • Mid-humeral Hind limb • Coxofemoral disarticulation • Mid-femoral • Limb removal with via acetabulectomy/hemipelvectomy Digit Tail AMPUTATION: INDICATIONS Trauma resulting in significant dysfunction • Irreparable damage to local structures • Financial limitations preventing repair Neoplasia Neurological deficits • Traumatic event or focal disease • Chronic repetitive trauma to limb Behavioral disorders • Common in tail Patient must be able to ambulate on remaining limbs PROGNOSIS FOR LIMB AMPUTEES Functional outcome depends on • Hind limb versus forelimb • • • • • • Weight distribution 60:40 (fore:hind) • Faster adaptability after hind limb amputation Function of remaining limbs Preoperative adaptation of patient Body condition score Body size Systemic health Long term survival • Dependent on reason for amputation AMPUTATION: FORELIMB Forequarter is gold standard- • Neoplastic bone lesions typically in proximal humerus Scapulohumeral level - • No added benefit • Aesthetically inferior • Potential for pressure sores over scapula Mid-humeral - • Dysfunctional stump • Prosthesis not applicable AMPUTATION: HIND LIMB Coxofemoral disarticulation versus mid-femur • Surgeon’s preference • Mid-femur may provide more groin protection • Location of neoplastic lesion Limb removal with acetabulectomy or hemipelvectomy • Reserved for proximal femur and acetabular tumors • Technically more challenging • Esthetically inferior PERIOPERATIVE CONSIDERATIONS Limb amputations are very painful procedures Nerve blocks • Epidural analgesia • Intraoperative lidocaine - bupivacaine Postoperative pain management • Systemic • Local • Infusion catheters • Sustained release local blocks • Liposome-encapsulated bupivacaine LIMB AMPUTATION: AFTER CARE AND COMPLICATIONS After care • Incision care • Pain management Potential complications • Mobility issues • Typically temporary • Wound complications • Dehiscence, infection, delayed healing Long term survival • Existing and developing comorbidities • Underlying cause of amputation AMPUTATION: DIGITS Anatomy: digits 1-5 • Each with 3 phalangeal bones except digit 1 • Associated sesamoid bones • 3rd and 4th are primary weight bearing • 2nd and 5th are secondary support • 1st vestigial/redundant (dewclaw) AMPUTATION: DIGITS Highest level possible in feet • Manus: metacarpophalangeal (MCP) • Pes: metatarsophalangeal (MTP) • Requires foot pad transfer Lower levels at interphalangeal joints AMPUTATION: DIGITS Single digit removal is well tolerated Digits 3 and 4 may cause more lameness • Fusion podoplasty of adjacent toes may help • Prevents discomfort due to toe splaying DEWCLAW AMPUTATION Be aware they may be breed standard! • Great Pyrenees (single forelimb and double hind limb declaws) Indications • Prevents trauma and ingrown nail Puppies • 3-5 days of age • Excision under local anesthesia • Silver nitrate stick for hemostasis Adults • Under general anesthesia • MCP/MTP disarticulation • Minor surgical procedure DIGIT AMPUTATION: AFTER CARE AND COMPLICATIONS After care • Incision care • Pain management Increased risk of complications • Digits 3 and 4 > 2 and 5 • Higher body weight • Hind > front toes Potential complications • Lameness (toe amputations) • Mobility issues in three legged patients • Wound complications • Dehiscence, infection, delayed healing ONYCHECTOMY Declawing • Distal interphalangeal (DIP) amputation • P2-P3 disarticulation ONYCHECTOMY Indications in dogs • Trauma • Neoplasia • Squamous cell carcinoma, melanoma, sarcomas • Infection • Onychomycosis, Staphylococcus spp., demodicosis • Rarely behavioral ONYCHECTOMY Indications in cats • Medical • Treatment of trauma, tumor, infection • Elective • Human benefit • Thwarting unwanted scratching behavior • Improvement of owner-pet relationship • Owners at risk from complications from cat scratches • Immunodeficiency, geriatric, diabetic • Cat benefit • Alternative to relinquishment, outdoor housing or euthanasia ELECTIVE ONYCHECTOMY IN CATS • Mostly in forelimb; may be done on all four limbs • Long term requirements • Claws as defense mechanism are lost • Cannot climb to avoid threats • Must remain indoors for the rest of their lives ELECTIVE ONYCHECTOMY IN CATS Under general anesthesia Tourniquet placement Local block Surgical techniques • Scalpel • CO2 laser • Guillotine Wound closure • Tissue glue or monofilament suture ONYCHECTOMY CONSIDERATIONS Intra and postoperative bleeding • Scalpel, guillotine> CO2 laser • Many require post op bandages for 24 hours Cost • CO2 laser > scalpel, guillotine Safety requirements for laser Postoperative pain • Less in CO2 laser Post op care • Paper litter critical • Monitoring for bleeding • Pain management ONYCHECTOMY COMPLICATIONS Short-term • Hemorrhage • Infection • Incisional granuloma • Lameness • Foot pad injury • Residual P3 bone • Radial neuropathies • Distal limb ischemia Long-term • Persistent lameness • Claw regrowth ~3-15% • Guillotine> scalpel> CO2 laser • Flexor tendon contracture ELECTIVE ONYCHECTOMY IN CATS Welfare concerns • Pain • Postoperative • Persistent lameness • Older> younger cats • Surgical complications • Behavior • Impairment of normal behavior • Development of problem behavior • Aggression • Biting • Inappropriate elimination • Older > younger cats ELECTIVE ONYCHECTOMY IN CATS “Sensitive topic” • Legislation varies depending on location • Examples: banned in California, Colorado, New York • Banfield, VCA and BluePearl clinics no longer offer it AVMA policy 2020 • Declawing as an elective procedure in cats is discouraged • Supportive of non-surgical alternatives and owner counseling • Respects veterinarian’s judgment AVMA literature review on welfare and implications of procedure • Available on Brightspace ELECTIVE ONYCHECTOMY IN CATS Alternatives options • Environmental modifications • Appropriate scratching posts • Pheromone sprays/plug-ins • Kitty-proofing inappropriate surfaces (sticky tape, tinfoil) • Behavioral training • Positive reinforcement training of kittens • Nail care • Frequent nail trims; every 1-2 weeks • Nail caps; replace every 4-6 weeks ELECTIVE ONYCHECTOMY IN CATS Alternative surgical procedure? • Deep digital flexor tenectomy • Less postoperative pain • Long term lameness similar • Inability to expose claw results in claw ingrowth • Requires regular nail trimming Not recommended by AVMA and CVMA as an alternative CAUDECTOMY: INDICATIONS Therapeutic • Trauma • Acute or repetitive • Musculoskeletal /neurological • Infection • Chronic wound • Neoplasia Working dogs • Controversial • Preventing injuries; not evidence based Cosmetic (tail docking) • Very controversial For more details go to AVMA.org • Banned in some countries CAUDECTOMY (TAIL AMPUTATION) Level of amputation • Tail base (complete) • At Cd2-Cd3 vertebrae • Chronic pyoderma • Avulsion tail injuries • Partial • Therapeutic • Leave 2-3 cm of healthy tissue • Cosmetic (controversial) • Breed standard charts • Owner preference CAUDECTOMY: AGE CONSIDERATIONS Puppies < 1 week old • Controversial • They feel pain! • Local anesthesia transection with scissors and closure Dogs and cats >1 week old • General anesthesia • Epidural anesthesia • Partial or complete amputation Unethical technique • Raise awareness • Rubber band technique • Tail sloughs off distal to band in a week POST OPERATIVE CARE FOR ALL AMPUTATIONS Owner education Elizabethan collar • Until incision(s) healed Activity restriction Pain management • 7-10 days • Non-steroidal anti-inflammatory drugs Incision care • Bandage care if needed Recheck appointment • Incision check in 10-14 days ARTHRODESIS VERSUS ANKYLOSIS Arthrodesis • Surgically created bony fusion across a joint space Ankylosis • Abnormal loss of motion in a joint from disease, trauma, prolonged immobilization (cast/splint), or infection • Does not produce a bony union • Maintains painful, unstable status of the joint ARTHRODESIS: INDICATIONS 1. End-stage osteoarthritis (OA) • Sequelae of any type of arthritis 2. Non-reconstructable articular fractures 3. Irreparable soft tissue trauma to periarticular stabilizers • Calcaneal tendon injury • Carpal hyperextension injury • Traumatic luxations 4. Some neurologic deficits • Radial nerve (carpus) • Peroneal nerve (tarsus) PRINCIPLES OF ARTHRODESIS Goals • Restoration of joint stability • Resolution of pain Three requirements to achieve fusion 1. Complete removal of articular cartilage 2. Placement of cancellous bone graft 3. Rigid fixation of joint at a functional angle Types of arthrodesis • Partial (in multi-level joints) • Complete ARTHRODESIS: CANDIDATE JOINTS Forelimb • Shoulder • Elbow • Carpus • Pancarpal arthrodesis • Partial carpal arthrodesis Hind limb • Stifle • Tarsus • Pan tarsal arthrodesis • Partial tarsal arthrodesis Metabones and phalangeal joints ARTHRODESIS: AFTER CARE AND COMPLICATIONS After care • • • • Pain management Incision care +/- splint/bandage care Activity restriction Recheck radiographs ~4-6 weeks Complications • • • • Same as repaired fractures Incomplete fusion Failure of adjacent joints Potential need for implant removal LIMB SPARING SURGERY Goal • Sparing limb that otherwise requires amputation Indications • Patient not a candidate for amputation • Concurrent neurologic or orthopedic disease • Large-giant breeds • Previously amputated limb • Client refusal to amputate? Most commonly performed for distal radius osteosarcoma LIMB SPARING SURGERY CONSIDERATIONS High complication rates ~40-75% Poor long-term outcome in cancer patients Expensive Technical expertise of team critical Patient factors • Systemic health • Compliance Client factors • Compliance • Understanding of what is involved and prognosis • Finances LIMB SPARING SURGERY: DISTAL RADIUS Technique principles for distal radius • Removal of affected bone with adequate margins • Bridging of gap • Graft, implant, bone transport osteogenesis • Rigid stabilization with implants Complications • • • • Infection Implant related complications Local recurrence ~25% Distant metastatic disease LIMB SPARING SURGERY: OTHER APPROACHES May not require stabilization • Partial ostectomy of ulna with neoplasia Partial amputation and endoprosthesis • Technique • Amputation of affected portion of limb with margins • Implantation of custom-made, fitted endoprosthesis • Expensive • Not widely available • High complication rate at skin-implant interface • Stay tuned! JOINT REPLACEMENT Salvage procedure for joints • Replacement of part or entirety of a joint with prosthesis Candidate joints • Dogs • Hip • Stifle • Tarsus (very recent) • Elbow (high complication rates) • Cats • Hip JOINT REPLACEMENT Goals • Restoration of normal joint function • Resolution of joint pain Indications • End-stage OA • Irreparable articular fractures • Certain joint laxities • Hip dysplasia • Cranial cruciate rupture with advanced OA JOINT REPLACEMENT Contraindications • Neurological disorders • Infection • Lack of owner or patient compliance • Presence of malignancy Prognosis and complications • Excellent for hip; complication rates <20% • Good to excellent for stifle • Fair for elbow • Unknown for tarsus TAKE HOME MESSAGE • Amputation is a broad terminology and each level has unique indications • Patient’s ability to ambulate postoperatively is a critical factor in electing amputation as a treatment option • Elective onychectomy and cosmetic caudectomy procedures should be discouraged • Arthrodesis options are available for a variety of joints as a salvage procedure • Limb sparing surgery has high complication rates and requires careful decision making and client education • Joint replacement is a salvage procedure for joints that is available for a variety of joints in dogs and cats