TKA Complications

Topic updated on 04/26/14 7:55pm
  • Overall incidence 1% 
  • Risk factors
    • obesity
    • prior surgery
    • diabetes
    • inflammatory arthritis
  • Evaluation includes CRP, ESR, WBC, and knee aspiration
    • aspirate WBC count >1,100 with greater than 60% PML should raise suspicion 
  • Skin necrosis
    • exposed patellar tendon and tibia tubercle best treated with medial gastrocnemius flap 
    • exposed patella only can be treated with wet-to-dry dressings only
  • Incidence 1-2%
    • accounts for 10-20% of revisions
  • Types
    • axial instability (mediolateral)
    • flexion instability (anteroposterior)
  • Risk factors
    • ligament imbalance
    • poor alignment of components
    • implant design
    • bone loss
      • over resection of femur
      • femoral or tibial component loosening
    • collateral ligaments
      • laxity
      • underrelease
      • overrelease
      • traumatic disruption
    • connective tissue disorder
      • rheumatoid
      • Ehlers-Danlos
    • inaccurate bone resection
  • Axial instability
    • if flexion and extension symmetric
      • thicker tibial liner
    • if flexion and extension asymmetric
      • augmentation and component revision
  • Flexion instability 
    • occurs when flexion gap greater than extension gap
      • when femoral component is downsized or moved anterior
      • posterior dislocation in 0.15% of TKAs with posterior stabilization
      • can occur with PCL-retaining designs  
        • should be revised to posterior-stabilized TKAs
      • posterior-stabilized TKAs need to be revised if dislocation recurrent
Vascular Injury
  • Incidence is low
  • Document vascular exam pre and postoperatively
  • Risk factors
    • sharp dissection in posterior compartment of knee
    • posterior retractor placement
      • stay medial with retractor
      • popliteal artery 9mm posterior to posterior cortex when knee flexed to 90 degrees
  • Drop tourniquet
    • if arterial injury suspected
    • consider dropping after bone cuts
  • Popliteal artery injury can lead to
    • acute ischemia
    • compartment syndrome
    • potential amputation
Blood Loss & Anemia
  • Risk factors
    • closed suction drainage
      • closed suction drainage after total knee arthroplasty is associated with increased incidence of transfusion 
Nerve Palsy
  • Incidence 0.3%
  • Risk factors
    • increased risk for peroneal nerve palsy: 
      • preoperative valgus and/or flexion deformity  
        • incidence increases to 3-4% with valgus deformity
      • tourniquet time > 120 min
      • postoperative use of epidural analgesia
      • aberrant retractor placement
      • preoperative diagnosis of neuropathy (centrally or peripherally)
  • Treatment
    • if peroneal nerve injury suspected then leg should be placed in flexed position and compressive dressings should be removed
    • AFO recommended
    • consider late nerve decompression or muscle transfer if dorsiflexion does not return 
  • Critical to follow patients during early postoperative period 
  • Risk factors
    • preoperative stiffness 
      • most important factor (as a general rule ultimate motion is preoperative motion +/- 10°)
    • large body habitus
    • female 
    • extreme varus
    • young patients
    • limited intraoperative extension
    • poor patient compliance
    • low pain tolerance
    • technical factors
      • overstuffing patellofemoral joint
      • mismatched gaps
      • malposition of component
      • joint line elevation
      • excessive tightening of extensor mechanism during closure
    • postoperative issues
      • infection
      • delayed wound healing
      • periprosthetic fracture
      • complex regional pain syndrome
      • HO
  • New Postoperative Flexion contracture
    • usually due to hamstring spasm
      • caused by abnormal balance between quadriceps and hamstrings following surgery
      • usually will resolve in ~ 6 months
      • prevent with diligent flexion-extension exercises 1-3 months postop
    • another possible cause is tight closure of the anterior soft tissues
      • (new studies have shown soft tissue closure in knee flexion may prevent flexion contractures)
  • Treatment
    • manipulation under anesthesia 
      • indications
        •  flexion <90 degrees  after first 6 weeks postoperatively
          • over aggressive manipulation
            • fracture
            • extensor mechanism disruption
      • after >3 months postoperatively, manipulation associated with greater risk and lower benefit
    • scar excision, quadricepsplasty, possible revision of components
      • indications
        • persistent late stiffness
  • Prevention
    • CPM machines have not been shown to improve the long term range of motion or clinical outcomes  
Extensor Mechanism Rupture
  • Overview
    • patellar tendon rupture is a rare and devastating complication after TKA with an incidence reported ranging from 0.17% to 2.5%
    • Quadriceps tendon rupture extremely rare ~1%.
  • Treatment
    • reconstruction with an Achilles tendon/bone allograft 
Wound Complications
  • Risk factors
    • systemic factors
      • DM II
      • vascular disease
      • Rheumatoid arthritis
      • certain medication
      • tobacco
      • poor nutritional status
      • albumin <3.5g/dL
      • total lymphocyte count <1,500/uL
      • perioperative anemia
      • obesity
    • local factors
      • previous incision
        • skin bridges should be >5-6cm
        • avoid crossing previous skin incisions at an angle <60 degrees
      • knee deformity
      • skin adhesions
      • poor local blood supply
    • technique
      • large subcutaneous skin flaps
      • not preserving subcutaneous fat layer
    • postoperative
      • hematoma
      • flexion of knee >40 degrees for first 3-4 days
      • nasal oxygen should be used for first 1-2 days in at-risk patients
      • if wound drainage occurs for longer than 4 days then aggressive surgical management should be done
Metal Hypersensitivity
  • Overview
    • rare
    • nickel found in cobalt-chromium alloys is the most common offending agent. 
Heterotopic Ossification 
  • Less frequent than after THA
  • risk factors
    • periosteal stripping off anterior femur
      • formation of HO proximal to anterior flange of femoral component
      • leads to tethering of extensor mechanism/ quads
    • HO may indicate indolent infection
    • following arthrofibrosis
    • male gender
    • obesity
    • post traumatic deformity


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Qbank (17 Questions)

(OBQ12.207) A 56-year-old male undergoes an uncomplicated revision total knee arthroplasty. Post-operatively, he is noted to have a foot drop that has persisted despite conservative management. At two months, the patient undergoes external neurolysis with no improvement in function. At 18 months follow-up, he demonstrates passive ankle dorsiflexion 10 degrees past neutral, complete absence of active dorsiflexion, and 5/5 inversion strength. Which of the following is the most appropriate treatment at this time? Topic Review Topic

1. Ankle-foot orthosis (AFO) and physical therapy
2. Repeat neurolysis with possible nerve repair
3. Peroneus tertius transfer
4. Peroneus tertius transfer with achilles tendon lengthening
5. Posterior tibial tendon transfer to dorsum of foot

(OBQ11.126) A patient undergoes the procedure depicted in Figures A and B with standard components (non-gender specific). Which of the following outcomes most appropriately describes the difference in females compared to males for this procedure? Topic Review Topic
FIGURES: A   B        

1. Greater implant survivorship
2. Decreased WOMAC scores
3. Increased rate of extensor mechanism rupture
4. Increased postoperative pain
5. Increased component osteoloysis

(OBQ11.250) A 64-year-old male underwent the procedure shown in Figures A and B 7 weeks ago. He complains of difficulty with going down stairs. He reports no pain and denies constitutional symptoms. On examination the incision is well healed and no effusion is present. He is able to perform a straight leg raise with 5/5 strength. He lacks 2 degrees of terminal extension and has 80 degrees of active flexion. The knee is stable to varus and valgus stress testing at extension and mid flexion. His C-reactive protein and erythrocyte sedimentation rate are normal. What is the next most appropriate step in management? Topic Review Topic
FIGURES: A   B        

1. Manipulation under anesthesia
2. Cortisone injection followed by physical therapy for quadriceps strengthening
3. Aspiration to evaluate for septic arthritis
4. Revise femoral component by downsizing A-P diameter
5. Revise tibial component and add 5 degrees of posterior tibial slope

(OBQ10.62) A 65-year-old male undergoes a primary total knee arthroplasty. His preoperative radiographs are seen in figures A and B. Postoperative examination reveals an inability to dorsiflex his ankle or extend his toes. Sensation is decreased along the dorsum of his foot as well as between the 1st and 2nd toes. All of the following are risk factors for this complication following total knee arthroplasty EXCEPT? Topic Review Topic
FIGURES: A   B        

1. Aberrant retractor placement
2. Postoperative epidural analgesia
3. Correction of a 20 degree preoperative valgus deformity
4. Excessive medial release
5. Preoperative diagnosis of neuropathy

(OBQ10.109) Which of the following statements regarding the use of continuous passive motion (CPM) devices following total knee arthroplasty is true? Topic Review Topic

1. The use of CPM decreases the incidence of knee flexion contracture at 6 months following surgery.
2. The use of CPM has been associated with a decreased incidence of secondary surgery for knee manipulation.
3. The use of CPM has not demonstrated any difference in clinical outcomes at one year following surgery.
4. The use of CPM has been associated with increasing analgesic pain requirements in the first 3 days following surgery.
5. The use of CPM decreases knee flexion at one year following surgery.

(OBQ10.147) A 65-year-old woman complains of worsening left knee pain 7 months following total knee arthroplasty. She reports good pain relief for the initial 5 months following surgery. Physical exam is notable for a stable knee with range of motion from 0-115 degrees. Radiographs are provided in Figures A and B. Which of the following is the most appropriate next step in management? Topic Review Topic
FIGURES: A   B        

1. Nuclear bone scan
2. One stage revision total knee arthroplasty
3. Knee MRI
5. Physical therapy with focus on range of motion and quadriceps strengthening

(OBQ10.201) A posterior cruciate retaining total knee arthroplasty is contraindicated in all of the following patients EXCEPT? Topic Review Topic

1. 52-year-old female with severe rheumatoid arthritis of the knee
2. 73-year-old male with post-traumatic arthritis of the knee and prior patellectomy
3. 67-year-old male with degenerative arthritis and 10 degree valgus deformity of the knee
4. 55-year-old male with post-traumatic arthritis of the knee 20 years after bicruciate ligament ruptures
5. 63-year-old female with a chronic history of steroid treatment of systemic lupus erythematosus and an arthritic knee

(OBQ10.270) A 55-year-old patient is scheduled for total knee arthroplasty. A radiograph is provided in Figure A. Each of the following are risk factors for heterotopic ossification EXCEPT? Topic Review Topic
FIGURES: A          

1. Valgus knee deformity
2. Male gender
3. Obesity
4. History of trauma
5. Presence of preoperative osteophytes (hypertrophic arthrosis)

(OBQ09.230) A 66-year-old female presents with knee instability going down stairs 18 months after a posterior cruciate retaining total knee arthroplasty. She reports having recurrent effusions. Radiographs are shown in Figure A. What is the most likely cause for her instability? Topic Review Topic
FIGURES: A          

1. Intraoperative rupture of the patellar tendon
2. Alteration of the joint line
3. Posterior cruciate insuffiency
4. Anterior cruciate insufficiency
5. Catastrophic component loosening

(OBQ07.222) A 65-year-old female has severe knee arthritis with a significant flexion contracture and valgus deformity. In the recovery room following her total knee replacement, she is unable to dorsiflex her ankle. Management should include? Topic Review Topic

1. Application of an AFO to prevent an equinus contracture
2. Unwrap any compressive dressings and flex the knee
3. Immediate EMG
4. Open exploration of the peroneal nerve
5. Reassurance

(OBQ06.198) A 54-year-old woman is at physical therapy 3 months after a total knee arthroplasty when she feels a pop and develops increased pain in her knee. She continues therapy for another 3 months but reports weakness and frequent buckling. On exam, she has full passive extension but a 60 degree extensor lag. A lateral radiograph is shown in Figure A. What is the treatment of choice? Topic Review Topic
FIGURES: A          

1. Reconstruction with a bone-tendon allograft
2. Repair augmented with hamstring autograft
3. Continued therapy and strengthening
4. Arthrodesis
5. Treatment with orthotics for support

(OBQ05.142) A 65-year old healthy male has just undergone primary total knee arthroplasty. Which of the following is associated with use of a closed suction drain in this procedure? Topic Review Topic

1. Increased incidence of wound dehiscence
2. Increased incidence of transfusion
3. Decreased incidence of infection
4. Decreased incidence of hematoma formation requiring return to OR
5. Decreased pain scores on post-op days 1 and 2

(OBQ05.153) All of the following are risk factors for post-operative total knee arthroplasty periprosthetic supracondylar femur fractures EXCEPT: Topic Review Topic

1. Rheumatoid arthritis
2. Parkinson's disease
3. Chronic steroid therapy
4. Revision knee arthroplasty
5. Male gender

(OBQ04.82) What preoperative knee deformity puts a patient at most risk for a postoperative peroneal nerve palsy after total knee arthroplasty? Topic Review Topic

1. Valgus deformity only
2. Valgus and flexion contracture
3. Varus and flexion contracture
4. Varus deformity only
5. Flexion contracture only

(OBQ04.103) A 62-year-old female underwent a primary total knee arthroplasty of the left knee 10 days ago. She presents to clinic with skin necrosis of the midline incision. There is no deep infection present upon aspiration of the knee joint. She undergoes superficial irrigation and debridement and is left with exposed patellar tendon as shown in Figure A. What is the most appropriate next step in management? Topic Review Topic
FIGURES: A          

1. Split thickness skin grafting
2. Twice daily wet-to-dry dressing changes with Dakin's solution until healing by secondary intention
3. Latissimus dorsi free flap transfer
4. Vacuum-assisted closure device until healing by secondary intention
5. Medial gastrocnemius muscle flap transfer and skin grafting



MacDonald SJ, Bourne RB, Rorabeck CH, McCalden RW, Kramer J, Vaz M
Clin. Orthop. Relat. Res.. 2000 Nov;(380):30-5. PMID: 11064970 (Link to Pubmed)
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