Patellar FractureMANAGEMENT

MUSCULOSKELETAL AND RHEUMATOLOGIC PRESENTATIONS · 12 SECTIONS

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641 items

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01Approach to the Critical Patient/attcp40

Immediate priorities

›Alarm features requiring immediate action

›Open fracture (2-7% of patellar fractures)

›Emergent irrigation and debridement

›Orthopedic surgery activation

›IV antibiotics within 1 hour of recognition

›Disrupted extensor mechanism

›Inability to perform straight leg raise

›Palpable gap in patellar tendon or quadriceps tendon

›Urgent orthopedic consultation required

›Neurovascular compromise

›Absent or diminished dorsalis pedis or posterior tibial pulse

›Peroneal nerve deficit: loss of dorsiflexion or first web space sensation

›Vascular surgery activation if arterial injury suspected

›High-energy mechanism evaluation

›Polytrauma screen

›Associated femur or tibial fractures

›Hip dislocation (dashboard mechanism)

›Pelvic ring injury

›If MVC or fall from height, activate trauma protocol

›Primary and secondary survey

›Whole-body CT trauma series if hemodynamically stable

Monitoring and targets

›Hemodynamic monitoring priorities

›Blood pressure

›SBP < 90 mmHg triggers hemorrhagic shock workup

›Isolated patellar fracture rarely causes hemodynamic instability

›Pain assessment

›NRS score at presentation and after analgesia

›Target NRS < 4 within 30 minutes

›Neurovascular checks

›Distal pulses, capillary refill, sensation, and motor function

›Reassess every 30 minutes until disposition decision

Immediate consults

›Consultation triggers

›Orthopedic surgery

›Any displaced fracture (articular step-off >2 mm or fragment separation >3 mm)

›Disrupted extensor mechanism

›Open fracture

›Comminuted fracture

›Vascular surgery

›Absent distal pulse or ankle-brachial index < 0.9

›Expanding hematoma or hard signs of vascular injury

02History/hx50

Mechanism of injury

›Injury mechanism characterization

›Direct blow

›Fall onto flexed knee

›Dashboard injury (MVC)

›Direct assault to anterior knee

›Indirect mechanism

›Sudden eccentric quadriceps contraction

›Stumbling or missing a step

›Forceful landing from jump

Symptom characterization

›Core symptoms

›Acute anterior knee pain at time of injury

›Immediate onset

›Delayed presentation suggests stress or pathologic fracture

›Swelling

›Rapid onset hemarthrosis typical

›Tense effusion within minutes to hours

›Functional impairment

›Inability to bear weight

›Inability to extend knee actively (critical finding)

›Sensation of pop or crack at injury

›Extensor mechanism integrity

›Straight leg raise ability is the critical historical question

›Inability to perform SLR indicates disrupted extensor mechanism

Risk factors

›Patient-specific risk factors

›Age and sex

›Median age 67 years, 64% female (Swedish Fracture Register data)

›Elderly postmenopausal women at highest risk

›Bone quality

›Osteoporosis or low bone mineral density

›Chronic steroid use

›Prior fragility fractures

›Comorbidities increasing complication risk

›Diabetes mellitus increases reoperation risk (OR 8.69)

›Cerebrovascular accident history increases infection risk (OR 6.18)

›Obesity increases extensor mechanism load

›Medication history

›Anticoagulant use increases hemarthrosis severity

›Bisphosphonate or steroid use

›Prior NSAID use for chronic pain

Prior history

›Relevant past history

›Prior knee injuries or surgeries

›Previous patellofemoral surgery

›Prior arthroscopy

›Total knee arthroplasty (periprosthetic fracture consideration)

›Prior patellar dislocation or subluxation

›Associated ligamentous laxity

›Trochlear dysplasia

›Prior DVT or PE

›Thrombophilia or hypercoagulable state

›Current anticoagulation

03Physical Exam/exam51

Inspection and palpation

›Anterior knee survey

›Swelling and deformity

›Tense hemarthrosis typical

›Visible deformity or patellar displacement in severe fractures

›Skin integrity

›Lacerations communicating with fracture indicate open fracture

›Abrasions over anterior knee

›Ecchymosis distribution

›Palpation findings

›Point tenderness over the patella

›Palpable gap between fracture fragments (high specificity)

›Step-off deformity

Extensor mechanism testing

›Functional integrity assessment

›Straight leg raise test

›Single most critical bedside test

›Inability to perform SLR indicates extensor mechanism disruption

›Partial extension lag with SLR suggests incomplete disruption

›Active knee extension range

›Inability to extend from 90 degrees flexion

›Extension lag quantification

Effusion and joint exam

›Joint effusion assessment

›Ballottement or fluid wave test

›Tense hemarthrosis typical with intra-articular fracture

›Fat globules on aspiration confirm lipohemarthrosis

›Range of motion

›Inability to flex to 90 degrees (Ottawa Knee Rule criterion)

›Document baseline ROM

›Patellofemoral tracking

›Patellar alta or baja on clinical exam

›Lateral patellar displacement suggests dislocation-related fracture

Neurovascular exam

›Distal neurovascular status

›Arterial pulses

›Dorsalis pedis pulse

›Posterior tibial pulse

›Capillary refill < 2 seconds

›Peroneal nerve function

›Active dorsiflexion strength

›Sensation at dorsal first web space

›Tibial nerve function

›Plantar flexion strength

›Plantar sensation

PITFALLS

›Examination pitfalls

›Missed open fracture

›Meticulous skin inspection required

›Even small lacerations near patella communicate until proven otherwise

›Partial extensor mechanism disruption

›Patient may perform weak SLR despite significant fracture

›Extension lag is the key finding

›Bipartite patella misidentified as fracture

›Superolateral location typical

›Smooth rounded cortical edges vs sharp fracture margins

04Differential Diagnosis/ddx49

Extensor mechanism injuries

›Quadriceps tendon rupture

›ICD-10: M66.352

›Suprapatellar gap on palpation

›Patella baja on lateral radiograph

›More common in patients older than 40 years

›Intact patella on radiograph distinguishes from patellar fracture

›Patellar tendon rupture

›ICD-10: M66.362

›Infrapatellar gap on palpation

›Patella alta on lateral radiograph

›More common in patients younger than 40 years

›Disrupted extensor mechanism identical to patellar fracture

Patellar pathology

›Patellar dislocation or subluxation

›ICD-10: S83.006A

›Lateral displacement of patella

›Positive apprehension test

›May have associated osteochondral fracture

›Medial patellar retinaculum tear

›Bipartite patella

›ICD-10: Q74.1

›Congenital accessory ossification center

›Superolateral location typical

›Smooth rounded cortical edges vs acute fracture margins

›Present bilaterally in approximately 50% of cases

Adjacent knee injuries

›Tibial plateau fracture

›ICD-10: S82.101A

›Joint line tenderness

›Valgus or varus stress pain

›Lateral plateau most commonly fractured (Schatzker classification)

›Osteochondral fracture

›ICD-10: S83.006A

›May be occult on plain radiographs

›Knee effusion with locking or catching

›MRI or CT required for diagnosis

›Prepatellar bursitis

›ICD-10: M70.40

›Anterior swelling localized to prepatellar bursa

›No bony tenderness on deep palpation

›Intact extensor mechanism and no fracture on imaging

Stress and pathologic fractures

›Patellar stress fracture

›ICD-10: M84.362A

›Insidious onset anterior knee pain

›Athletic population with repetitive loading

›Plain films may be negative early

›Pathologic fracture through tumor or metastasis

›ICD-10: M84.562A

›Low-energy mechanism disproportionate to fracture severity

›Prior malignancy history

›Lytic or blastic lesion on radiograph

05Laboratory Tests/lt35

Initial laboratory evaluation

›Routine labs for isolated closed patellar fracture

›Not routinely required

›Isolated closed non-displaced fracture in healthy young patient

›No surgical candidate workup needed

›Surgical candidate workup

›Complete blood count for baseline hemoglobin

›Basic metabolic panel including renal function

›Coagulation studies (PT, INR, aPTT) if anticoagulated or bleeding history

›Type and screen if significant blood loss anticipated

Thrombosis evaluation

›DVT risk assessment labs

›D-dimer

›Elevated D-dimer >0.5 mcg/mL is independent risk factor for preoperative DVT (OR 2.47)

›Symptomatic VTE rate approximately 0.6% without prophylaxis for isolated patellar fracture

›Consider in high-risk patients: age >52, delayed surgery, polytrauma, open injuries

›Platelet count

›Baseline prior to anticoagulation initiation

›Heparin-induced thrombocytopenia risk monitoring

Infection markers

›Infection workup indications

›Open fracture or delayed presentation

›CBC with differential for leukocytosis

›ESR and CRP as baseline infection markers

›Blood cultures if febrile or septic

›Postoperative infection concern

›CRP rises by day 3, normalizes by 2-3 weeks in uncomplicated surgery

›ESR remains elevated for weeks postoperatively

Metabolic bone disease screening

›Fragility fracture workup

›Vitamin D 25-OH level

›Deficiency common in elderly patellar fracture patients

›Target repletion to >75 nmol/l for bone healing

›Calcium and phosphate

›Hypocalcemia assessment

›Alkaline phosphatase for Paget disease screening

›Consideration for DEXA scan referral

›Low-energy mechanism in elderly patient

›T-score < -2.5 indicates osteoporosis

06Diagnostic Tests/dt84

Scoring Systems

›Ottawa Knee Rule

›Indications for radiograph: any one criterion positive

›Age 55 years or older

›Isolated patellar tenderness (no other bone tenderness)

›Fibular head tenderness

›Inability to flex knee to 90 degrees

›Inability to bear weight for 4 steps immediately and in ED

›Performance characteristics

›Pooled sensitivity 98.5-100%

›Specificity 48.6%

›Meta-analysis confirms safety for ruling out fracture when all criteria negative

›ACEP Level B recommendation for use in adults

›Limitations

›Not validated under age 18 in original studies

›Not applicable if altered mental status or intoxication

›Not designed to exclude patellar sleeve fracture in pediatric patients

›AO/OTA Classification

›Fracture pattern categories

›Type A: extra-articular fracture

›Type B: partial articular fracture (vertical, marginal)

›Type C: complete articular fracture (transverse, comminuted)

›Clinical utility

›Guides surgical planning and implant selection

›CT changes both classification and treatment plan in comminuted patterns

›Used in Swedish Fracture Register (3194 fractures studied)

MRI

›MRI indications for patellar fracture

›Primary indications

›Occult fracture with normal plain films and persistent symptoms

›Osteochondral injury assessment not visible on radiograph

›Soft tissue and ligamentous injury evaluation

›Patellar sleeve fracture in pediatric patients (cartilaginous component)

›Findings

›Bone marrow edema pattern confirms fracture

›Articular cartilage continuity assessment

›Medial patellofemoral ligament tear in dislocation-related fracture

›Quadriceps or patellar tendon integrity

›Limitations

›Not first-line for acute patellar fracture

›Longer acquisition time limits use in acute ED setting

›Metal artifact from prior hardware

›CT indications and protocol

›Preoperative planning

›Comminuted fractures underestimated by plain radiographs

›Complex articular patterns requiring 3D reconstruction

›CT changes both classification and surgical plan in comminuted fractures

›Protocol

›CT knee with 1-2 mm slices

›Multiplanar reformats in coronal and sagittal planes

›3D volume rendering for surgical planning

›Findings assessed

›Articular step-off quantification (critical threshold >2 mm)

›Fragment number and size

›Fracture pattern: transverse 56%, vertical 26%, comminuted, marginal

›Associated tibial plateau or distal femur injury

›ACR Appropriateness Criteria

›CT knee recommended for acute trauma when radiograph indeterminate or comminuted pattern

›Usually appropriate for preoperative planning

Ultrasound

›Ultrasound role in patellar fracture

›Extensor mechanism assessment

›Quadriceps tendon continuity

›Patellar tendon continuity

›Dynamic assessment of extensor mechanism during attempted SLR

›Effusion evaluation

›Hemarthrosis volume estimation

›Guide aspiration for diagnostic or therapeutic purposes

›Lipohemarthrosis (fat-fluid interface) confirms intra-articular fracture

›Limitations

›Cannot reliably characterize articular fracture extent

›Operator-dependent

›Plain radiography remains first-line imaging

Plain Radiography

›Radiograph protocol and interpretation

›Standard views

›AP knee radiograph

›Lateral knee radiograph (most informative view)

›Sunrise or Merchant (patellofemoral) view

›Lateral view findings

›Transverse fracture identification

›Fragment displacement measurement

›Patella alta (patellar tendon rupture) or baja (quadriceps tendon rupture)

›Lipohemarthrosis on cross-table lateral with horizontal beam confirms intra-articular fracture

›Measurement thresholds

›Articular step-off >2 mm: surgical threshold

›Fragment separation >3 mm: surgical threshold

›Patella alta ratio > 1.2 (Insall-Salvati) suggests patellar tendon disruption

07Disposition/dispo32

Discharge criteria

›Safe discharge parameters

›Non-displaced closed fracture

›Articular step-off <2 mm

›Fragment separation <3 mm

›Intact extensor mechanism (can perform SLR)

›Functional requirements for discharge

›Adequate pain control with oral analgesia

›Able to ambulate safely with crutches and knee immobilizer

›Reliable orthopedic follow-up within 5-7 days confirmed

›Patient understands non-weight-bearing or weight-bearing as tolerated restrictions

Admission criteria

›Indications for hospital admission

›Operative indications requiring inpatient management

›Open fracture requiring emergent irrigation and debridement

›Polytrauma with associated injuries

›Disrupted extensor mechanism requiring early surgical fixation

›Social and functional indications

›Inability to safely ambulate with crutches

›Inadequate home support or unsafe home environment

›High-energy mechanism requiring observation for associated injuries

›Significant comorbidities limiting outpatient management

Orthopedic referral triggers

›Urgent and non-urgent referral criteria

›Emergent orthopedic consultation (same encounter)

›Open fracture

›Neurovascular compromise

›Disrupted extensor mechanism

›Displaced fracture requiring operative fixation

›Urgent follow-up within 3-5 days

›Borderline displacement (2-3 mm)

›Repeat imaging to ensure no interval displacement

›Routine orthopedic follow-up within 5-7 days

›Non-displaced fracture managed conservatively

›Serial radiographs at 2, 4, and 6 weeks to monitor displacement

08Treatment/t82

Non-operative management

›Conservative management protocol

›Indications

›Non-displaced fracture with articular step-off <2 mm

›Intact extensor mechanism (able to perform SLR)

›Fragment separation <3 mm

›Accounts for approximately 67% of all patellar fractures

›Immobilization

›Knee immobilizer or hinged brace locked in full extension

›Duration 5-6 weeks

›Weight-bearing as tolerated with crutches

›Follow-up imaging protocol

›Repeat radiographs at 2 weeks to exclude interval displacement

›Repeat at 4 and 6 weeks to confirm consolidation

›ROM exercises initiated after fracture consolidation confirmed

Operative management

›Surgical indications

›Absolute indications

›Articular step-off >2 mm

›Fragment separation >3 mm

›Open fracture

›Disrupted extensor mechanism

›Surgical technique options

›Tension band wiring

›Most commonly used technique (24% of all cases in registry data)

›Converts tensile forces to compressive forces across fracture

›High rate of symptomatic hardware requiring removal (29.6%)

›Cannulated screw fixation

›Alternative for simple transverse fractures

›May be combined with tension band wiring

›Plate fixation

›Low-profile plates increasingly preferred

›Fewer symptomatic hardware complications than tension band wiring

›Partial or total patellectomy

›Reserved for severely comminuted fractures not amenable to reconstruction

›Associated with inferior long-term functional outcomes

›Open fracture protocol

›Emergent irrigation and debridement

›Antibiotic prophylaxis: cefazolin 2 g IV within 1 hour of recognition

›Tetanus prophylaxis

›Internal fixation at same setting when soft tissue permits

Analgesia protocol

›Multimodal analgesia

›First-line: topical NSAIDs

›Greatest net benefit for acute musculoskeletal injury

›Diclofenac gel 1% applied to anterior knee

›Minimal systemic absorption reduces GI and renal risk

›Oral NSAIDs

›Ibuprofen 400-600 mg orally every 6-8 hours

›Naproxen 500 mg orally every 12 hours

›OTA states no conclusive clinical evidence prohibiting NSAID use in fracture care

›Avoid in renal insufficiency, active GI bleeding, or significant cardiovascular disease

›Acetaminophen

›1 g orally every 6-8 hours

›Maximum 3-4 g per day

›Additive effect with NSAIDs

›Opioids

›No opioid achieves benefit greater than NSAIDs for acute musculoskeletal pain

›Opioids cause more harms than NSAIDs

›Short-course opioids only for severe pain refractory to multimodal therapy

›If required: oxycodone 5 mg orally every 4-6 hours as needed

DVT prophylaxis

›Venous thromboembolism prevention

›Risk stratification

›Symptomatic VTE rate approximately 0.6% without prophylaxis for isolated patellar fracture

›High-risk features: age >52, open injury, polytrauma, delayed surgery

›Elevated D-dimer >0.5 mcg/mL associated with preoperative DVT (OR 2.47)

›Prophylaxis options

›Low molecular weight heparin: enoxaparin 40 mg subcutaneous once daily

›Duration: while immobilized and non-weight-bearing

›Mechanical prophylaxis with compression stockings for all patients

›Contraindications

›Active bleeding or coagulopathy

›Severe thrombocytopenia (platelet count < 50)

Bone healing support

›Adjuncts to fracture healing

›Calcium supplementation

›Calcium carbonate 500-1000 mg orally twice daily with food

›Particularly in elderly and osteoporotic patients

›Vitamin D supplementation

›Cholecalciferol 800-2000 IU orally daily

›Target serum 25-OH vitamin D > 75 nmol/l

›Physical therapy referral

›After fracture consolidation (typically 6 weeks)

›Quadriceps strengthening program

›ROM restoration exercises

›Gait training

09Special Populations/sp70

Pregnancy

›Patellar fracture in pregnancy

›Mechanisms and incidence

›Falls are the most common injury mechanism in pregnancy

›Altered gait and balance in third trimester increases fall risk

›Center of gravity shift increases knee loading during falls

›Imaging considerations

›Plain radiography acceptable with abdominal shielding

›Radiation exposure to fetus from knee radiograph is negligible (<0.001 mGy)

›MRI preferred over CT for occult fracture in pregnancy

›CT knee with shielding acceptable if MRI not available

›Analgesia in pregnancy

›Acetaminophen 1 g every 6-8 hours is first-line and safe throughout pregnancy

›NSAIDs: avoid after 20 weeks gestation (risk of premature ductus arteriosus closure)

›Opioids: use sparingly with neonatal team awareness; risk of neonatal withdrawal

›Regional nerve block (femoral nerve block) preferred for procedural analgesia

›DVT prophylaxis

›Pregnancy is an independent DVT risk factor

›Low molecular weight heparin is safe in pregnancy; warfarin is contraindicated

›Compression stockings for all immobilized pregnant patients

›Surgical considerations

›Multidisciplinary team including obstetrics and anesthesia for operative cases

›Fetal monitoring perioperatively in viable pregnancy (>24 weeks)

›Left lateral tilt positioning to relieve aortocaval compression

Geriatric

›Patellar fracture in elderly patients

›Epidemiology

›Median age 67 years; 64% female in registry data

›Low-energy falls from standing height account for 70% of mechanisms

›Fragility fracture pattern; evaluate underlying bone quality

›Osteoporosis management

›DEXA scan referral for fragility fracture pattern

›Initiate or optimize calcium and vitamin D supplementation

›Consider bisphosphonate therapy after fracture healing

›Endocrinology or rheumatology referral for metabolic bone disease

›Analgesia considerations

›NSAID caution: higher risk of GI bleeding, renal impairment, cardiovascular events

›Acetaminophen remains safe as first-line agent

›Opioid risk: confusion, falls, constipation, respiratory depression in elderly

›If opioids required, use lowest dose for shortest duration

›DVT risk

›Age >52 is independent DVT risk factor in patellar fracture

›Immobility compounds thrombosis risk

›Anticoagulation with attention to fall risk and bleeding risk balance

›Functional recovery expectations

›Pre-injury ambulatory status documented

›Physiotherapy and occupational therapy assessment early

›Social work evaluation for discharge planning

›Full functional recovery may take 3-6 months or longer

Pediatrics

›Patellar fracture in skeletally immature patients

›Unique fracture patterns

›Patellar sleeve fracture: cartilaginous avulsion from inferior pole

›Easily missed on plain radiograph due to large cartilaginous component

›MRI or ultrasound required to characterize full extent

›Bipartite patella: congenital variant, not a fracture; distinguish clinically

›Ottawa Knee Rule limitations in pediatrics

›Original rule validated in patients 18 years and older

›JAMA Pediatrics review: clinical decision rules less validated in children

›Lower threshold for imaging in skeletally immature patients

›ACR Appropriateness Criteria: radiographs usually appropriate for acute knee trauma in children

›Mechanism in pediatrics

›Direct blow or sports injury more common than fall in younger patients

›Indirect avulsion from quadriceps contraction in adolescents

›Growth plate involvement: Sinding-Larsen-Johansson and Osgood-Schlatter as differentials

›Analgesia in pediatrics

›Ibuprofen 10 mg/kg orally every 6-8 hours (maximum 600 mg per dose)

›Acetaminophen 15 mg/kg orally every 4-6 hours (maximum 1 g per dose)

›Multimodal approach to minimize opioid exposure

›Operative considerations

›Growth plate sparing techniques when possible

›Pediatric orthopedic surgery referral for all displaced or sleeve fractures

›Higher healing potential than adults; conservative management favored when appropriate

10Background/b62

Epidemiology

›Incidence and distribution

›Fracture frequency

›Patellar fractures account for approximately 1% of all skeletal fractures

›Bimodal age distribution: young males (high-energy) and elderly females (low-energy)

›Median age 67 years, 64% female in Swedish Fracture Register (3194 fractures)

›Mechanism distribution

›Low-energy falls from standing height: approximately 70%

›High-energy mechanisms (MVC, fall from height): approximately 30%

›Direct blow vs indirect quadriceps contraction mechanism

›Fracture pattern distribution

›Transverse fracture: most common, 56% of cases

›Vertical fracture: 26%

›Comminuted: 15-30% depending on series

›Marginal and osteochondral: less common

›Treatment distribution

›Non-operative management: approximately 67% of all patellar fractures

›Surgical management: approximately 33%

›Tension band wiring: most common surgical technique (24% of all cases)

Pathophysiology

›Anatomic and mechanical basis

›Patella anatomy and function

›Largest sesamoid bone in the body

›Increases mechanical advantage of quadriceps by 50% at 0-45 degrees knee flexion

›Patellofemoral joint transmits forces up to 3-4 times body weight during stair climbing

›Articular cartilage is the thickest in the human body (up to 6 mm)

›Fracture mechanisms

›Direct blow: creates stellate or comminuted pattern from point loading

›Indirect eccentric quadriceps contraction: creates transverse fracture pattern (most common)

›Dashboard injury: direct blow with associated posterior cruciate or hip injury

›Extensor mechanism anatomy

›Quadriceps tendon inserts on superior pole

›Patellar tendon inserts on inferior pole and tibial tuberosity

›Medial and lateral retinaculum provide supplementary extension (30% of force)

›Disruption of all three (patella + retinaculum) causes complete loss of extension

›Articular consequences

›Intra-articular fracture causes hemarthrosis and lipohemarthrosis

›Cartilage damage predisposes to patellofemoral osteoarthritis

›Residual articular step-off >2 mm correlates with inferior long-term outcomes

Therapeutic Considerations

›Evidence base for treatment decisions

›Cochrane systematic review (Sayum Filho 2021)

›Insufficient high-quality RCT evidence to support one surgical technique over another

›Conservative management appropriate for non-displaced fractures with intact extensor mechanism

›Hardware removal common complication of tension band wiring

›Surgical complication rates (Vesterager systematic review 2024)

›Symptomatic hardware requiring removal: 29.6%

›Fixation failure: 5.2%

›Infection: 3.1%

›Nonunion: 1.7%

›Infection risk increased by diabetes (OR 8.69) and cerebrovascular accident history (OR 6.18)

›Analgesia evidence base

›Topical NSAIDs have greatest net benefit for acute musculoskeletal injuries (Busse 2020 network meta-analysis)

›Oral NSAIDs (ibuprofen, naproxen) recommended as secondary agents

›OTA and ACS guidelines recommend NSAIDs as part of multimodal analgesia for fractures

›No conclusive evidence that NSAIDs impair fracture healing at standard doses

›DVT prophylaxis evidence

›KAF cohort study (Selby 2014): symptomatic VTE rate 0.6% without prophylaxis for isolated lower limb fracture

›Yang 2024 (PloS One): DVT prevalence higher with age >52, open fractures, delayed surgery

›Individual risk stratification recommended rather than universal pharmacologic prophylaxis

›Long-term outcomes

›Non-operative fractures typically heal in 6-8 weeks

›Full functional recovery may take 3-6 months

›Patellofemoral osteoarthritis is common long-term sequela

›Extension lag and knee stiffness may persist in complex fractures

11Patient Discharge Instructions/pdi31

copy discharge instructions

›Discharge instructions for patellar fracture

›Your diagnosis and treatment

›You have been diagnosed with a patellar (kneecap) fracture

›Your fracture is non-displaced and your knee cap is in proper alignment

›You will wear a knee immobilizer brace to protect the fracture while it heals

›You can bear weight on your leg as tolerated with crutches for support

›Medications

›Take ibuprofen or naproxen as prescribed with food to reduce pain and swelling

›Acetaminophen can be used alongside ibuprofen for additional pain control

›Ice the knee for 15-20 minutes several times per day during the first 48-72 hours

›Elevate the leg above the level of your heart to reduce swelling

›Activity restrictions

›Keep the knee brace on at all times except for bathing

›No sports, running, or high-impact activities until cleared by your orthopedic surgeon

›Use crutches as instructed; weight bearing as tolerated unless otherwise specified

›Do not remove or adjust the brace without guidance from your orthopedic surgeon

›Follow-up appointments

›Orthopedic surgery appointment within 5-7 days is required

›Bring your brace to the appointment for assessment

›Repeat X-rays will be taken at follow-up to confirm fracture alignment

›Return to emergency department immediately for

›Sudden inability to straighten the leg or worsening extension loss

›Increasing pain despite medications

›Numbness, tingling, or new weakness in the foot or toes

›Calf swelling, redness, warmth, or pain (signs of blood clot)

›Wound drainage, increasing redness, warmth, or fever above 38.3 C (101 F)

›Pale, cold, or blue foot (signs of arterial injury)

›Recovery expectations

›Fracture healing typically takes 6-8 weeks

›Full return to normal activities may take 3-6 months

›Physical therapy will be recommended after fracture healing is confirmed

12References/r55

Guidelines and key sources

›Primary evidence sources

›Sayum Filho J et al. Interventions for Treating Fractures of the Patella in Adults. Cochrane Database of Systematic Reviews. 2021.

›Systematic review; insufficient high-quality RCT evidence to prefer one surgical technique

›https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009651.pub3/full

›Kruse M et al. Epidemiology, Classification and Treatment of Patella Fractures. European Journal of Trauma and Emergency Surgery. 2022.

›Observational study of 3194 fractures from the Swedish Fracture Register

›https://pubmed.ncbi.nlm.nih.gov/35644894

›Steinmetz S et al. Practical Guidelines for the Treatment of Patellar Fractures in Adults. Swiss Medical Weekly. 2020.

›Practical clinical guidelines including extensor mechanism assessment

›https://pubmed.ncbi.nlm.nih.gov/31940427

›Melvin JS, Mehta S. Patellar Fractures in Adults. Journal of the American Academy of Orthopaedic Surgeons. 2011.

›Comprehensive review of classification and management

›https://pubmed.ncbi.nlm.nih.gov/21464213

›Hargett DI et al. Patella Fractures: Approach to Treatment. Journal of the American Academy of Orthopaedic Surgeons. 2021.

›Current approach including multimodal analgesia and operative techniques

›https://pubmed.ncbi.nlm.nih.gov/33405488

Imaging and diagnostic guidelines

›Imaging evidence and decision rules

›Taljanovic MS et al. ACR Appropriateness Criteria Acute Trauma to the Knee. Journal of the American College of Radiology. 2020.

›Guidance on appropriate imaging modality selection for acute knee trauma

›https://linkinghub.elsevier.com/retrieve/pii/S1546-1440(20)30129-0

›Sims JI et al. Diagnostic Accuracy of the Ottawa Knee Rule in Adult Acute Knee Injuries. European Radiology. 2020.

›Systematic review and meta-analysis; sensitivity 98.5%, specificity 48.6%

›https://pubmed.ncbi.nlm.nih.gov/32222797

›Bachmann LM et al. The Accuracy of the Ottawa Knee Rule to Rule Out Knee Fractures. Annals of Internal Medicine. 2004.

›Original systematic review confirming Ottawa Knee Rule performance

›https://pubmed.ncbi.nlm.nih.gov/14734335

›Dreizin D et al. CT of Periarticular Adult Knee Fractures: Classification and Management Implications. Radiographics. 2024.

›CT role in fracture classification and surgical planning

›https://pubmed.ncbi.nlm.nih.gov/39146203

Complications and outcomes

›Surgical outcomes and DVT evidence

›Vesterager JD et al. Complications Following Surgical Treatment of Patella Fractures. European Journal of Trauma and Emergency Surgery. 2024.

›Systematic review; hardware removal 29.6%, fixation failure 5.2%, infection 3.1%

›https://pubmed.ncbi.nlm.nih.gov/38980395

›Kadar A et al. Predictors for Nonunion, Reoperation and Infection After Surgical Fixation of Patellar Fracture. Journal of Orthopaedic Science. 2015.

›Diabetes OR 8.69 for reoperation; CVA history OR 6.18 for infection

›https://pubmed.ncbi.nlm.nih.gov/25308213

›Selby R et al. Symptomatic Venous Thromboembolism Uncommon Without Thromboprophylaxis After Isolated Lower-Limb Fracture. Journal of Bone and Joint Surgery. 2014.

›KAF cohort; symptomatic VTE rate 0.6% without prophylaxis

›https://pubmed.ncbi.nlm.nih.gov/24875035

›Yang S et al. Deep Vein Thrombosis in Patients With Patellar Fractures. PloS One. 2024.

›DVT incidence and risk factors including elevated D-dimer (OR 2.47)

›https://pubmed.ncbi.nlm.nih.gov/39982917

Analgesia guidelines

›Pain management evidence

›Busse JW et al. Management of Acute Pain From Non-Low Back Musculoskeletal Injuries. Annals of Internal Medicine. 2020.

›Network meta-analysis; topical NSAIDs have greatest net benefit

›https://pubmed.ncbi.nlm.nih.gov/32805127

›Hsu JR et al. Clinical Practice Guidelines for Pain Management in Acute Musculoskeletal Injury. Journal of Orthopaedic Trauma. 2019.

›OTA guidelines recommending multimodal analgesia

›https://pubmed.ncbi.nlm.nih.gov/30681429

›Bernard A et al. Best Practices Guidelines for Acute Pain Management in Trauma Patients. American College of Surgeons. 2020.

›ACS guidelines supporting NSAIDs in fracture care

›https://www.facs.org/media/exob3dwk/acute_pain_guidelines.pdf

›MacDonald J et al. Acute Knee Injuries in Children and Adolescents: A Review. JAMA Pediatrics. 2021.

›Pediatric acute knee injury management including decision rule limitations

›https://jamanetwork.com/journals/jamapediatrics/fullarticle/10.1001/jamapediatrics.2020.6130

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Comprehensive Clinical Review

Structured, evidence-informed, long-form analysis for deeper understanding.

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.