›If severe pain, parenteral opioid titration with monitoring
›If sedation required for reduction of dislocation, procedural sedation pathway
Immobilization and Splinting
›Immobilization choice
›Knee immobilizer in full extension
›Hinged knee brace locked in extension if available
›Immobilization principles
›Extension to approximate tendon ends
›Avoid flexion positioning
›Neurovascular recheck after immobilization
›Adjuncts
›Elevation
›Ice
›Compression wrap if tolerated and no vascular compromise
Reduction
›Reduction indications
›If concurrent patellar dislocation, reduction when safe
›If knee dislocation, emergent reduction with vascular precautions
›Analgesia and anesthesia options
›Non opioid analgesia
›Acetaminophen PO 1000 mg once
›Ibuprofen PO 400 mg once if no contraindication
›Naproxen PO 500 mg once if no contraindication
›Opioid titration
›Fentanyl IV 0.5 to 1 microgram per kg
›Repeat 0.25 to 0.5 microgram per kg every 5 minutes to effect
›Hydromorphone IV 0.2 to 0.5 mg
›Repeat 0.2 mg every 10 to 15 minutes to effect
›Regional anesthesia
›Femoral nerve block ultrasound guided
›Ropivacaine 0.5% 15 to 20 mL
›Maximum total ropivacaine 3 mg per kg
›Adductor canal block ultrasound guided
›Ropivacaine 0.5% 15 to 20 mL
›Sensory predominant option for anterior knee
›Procedural sedation if required
›Sedation setup
›Airway equipment at bedside
›Suction ready
›Continuous monitoring including capnography
›Ketamine IV
›Initial 1 mg per kg IV
›If inadequate, additional 0.5 mg per kg IV
›Repeat every 5 to 10 minutes to effect
›Propofol IV
›Initial 0.5 to 1 mg per kg IV
›If inadequate, 0.25 to 0.5 mg per kg IV boluses
›Repeat every 1 to 3 minutes to effect
›Post reduction requirements
›Neurovascular recheck
›Post reduction radiographs when dislocation reduced
›Immobilization in extension
Open fracture medications and timing
›Open injury antibiotics
›Cefazolin IV 2 g once
›If severe beta lactam allergy, clindamycin IV 900 mg once
›If gross contamination, add gentamicin IV 5 mg per kg once per local protocol
›Tetanus prophylaxis
›If unknown or incomplete immunization, tetanus toxoid vaccine
›If dirty wound and immunization incomplete or unknown, tetanus immune globulin per local protocol
›Wound care
›Sterile saline soaked dressing
›Avoid probing in ED
›Urgent orthopedics
DVT prophylaxis when relevant
›Risk assessment
›Lower limb immobilization
›Prior VTE
›Active malignancy
›Significant mobility limitation
›Prophylaxis decisions
›If high risk and prolonged immobilization anticipated, align with local protocol and orthopedics plan
›If imminent surgery planned, coordinate timing with orthopedics
09Special Populations/sp21
Pregnancy
›Pregnancy considerations
›Fall mechanism and fetal monitoring needs by gestational age
›Imaging shielding and justification
›Analgesia selection
›Medication safety
›Avoid NSAIDs in later pregnancy per obstetric guidance
›Opioid short course risk benefit discussion
Geriatric
›Older adult considerations
›Higher spontaneous or low energy rupture risk with systemic disease
›Higher fall risk and mobility support needs
›Delirium risk with opioids and sedatives
›Disposition bias
›Lower threshold for admission if unsafe ambulation
›Early physiotherapy and gait aid planning
Pediatrics
›Pediatric considerations
›Tibial tubercle avulsion fracture mimic
›Patellar sleeve fracture consideration
›Growth plate injury patterns
›Management differences
›Early pediatric orthopedics involvement
›Weight based analgesia dosing per local pathway
10Background/b28
Epidemiology
›Occurrence patterns
›Rare injury
›More common in physically active adults
›Male predominance reported in many series
›Risk context
›Systemic disease increases susceptibility
›Tendinopathy and prior surgery increase risk
Pathophysiology
›Mechanism
›Failure of patellar tendon as part of extensor mechanism
›Eccentric quadriceps contraction against flexing knee as common pathway
›Tear locations
›Inferior pole of patella
›Midsubstance
›Tibial tubercle insertion
›Functional consequence
›Loss of active knee extension
›Patella alta due to unopposed quadriceps tension
Therapeutic Considerations
›Treatment rationale
›Complete rupture typically requires operative repair for restoration of extensor mechanism
›Early repair generally associated with easier mobilization and less retraction
›Partial tear with intact extensor mechanism may be managed nonoperatively in selected cases
›Immobilization rationale
›Extension reduces gap and protects healing or limits pain
›Flexion increases tension and separation at rupture site
›Recommendation style framing
›Class I recommendation based on expert consensus for urgent orthopedic evaluation in suspected complete rupture
›Class IIa recommendation based on expert consensus for MRI when exam equivocal or partial tear suspected
›ACEP Level B recommendation for capnography as adjunct monitoring during ED procedural sedation
11Patient Discharge Instructions/pdi21
Copy discharge instructions
›Discharge packet
›Knee immobilizer locked in full extension at all times unless told otherwise
›Non weight bearing with crutches or walker unless told otherwise
›Elevation above heart level when resting
›Ice 15 to 20 minutes up to every 2 to 3 hours for 48 hours
›Keep brace dry and intact
›Pain plan
›Acetaminophen 1000 mg every 6 to 8 hours as needed
›Ibuprofen 400 mg every 6 to 8 hours as needed if safe for you
›Opioid only if prescribed and smallest amount needed
›Follow up timing
›Orthopedics within 24 to 48 hours if complete rupture suspected
›Orthopedics or sports medicine within 3 to 7 days if partial tear suspected
›Return to ED now
›New numbness or weakness in foot
›Foot becomes cold pale or blue
›Severe increasing pain not controlled with meds
›Rapidly increasing swelling
›New inability to move toes
›Fever or wound drainage
›Brace too tight or worsening tingling after brace placement
12References/r8
Clinical guidelines and evidence sources
›Core references
›ACEP Clinical Policy Procedural Sedation and Analgesia in the Emergency Department
›AAOS OrthoInfo patient and clinician education on extensor mechanism injuries
›Review articles on acute patellar tendon rupture management and outcomes
›Evidence statements
›Capnography adjunct monitoring during ED procedural sedation ACEP Level B recommendation
›Timely surgical repair for complete patellar tendon rupture commonly recommended in orthopedic consensus guidance
›MRI utility for partial tears and equivocal exams supported in orthopedic diagnostic pathways
Evidence & Review
Reviewed by SymptomDx Medical Team·Last reviewed
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