TKA Complications

Death Patellar Clunk Syndrome
Periprosthetic Infection Patellofemoral Instability
Pulmonary emboli DVT
Patella fracture Instability
Component Loosening Popliteal artery injury
Tibial tray wear Quadriceps Tendon Rupture
Peroneal Nerve Palsy Patellar Tendon Rupture
Periprosthetic Femur Fracture Stiffness
Periprosthetic Tibial Fracture Fat Embolism
  MCL Rupture
Wound Complications / Skin slough Review References


  • 0.53% (SooHoo NF, JBJS 2006;88:480)
  • Risk Factors: comorbid medical conditions
  • Prevention: Preoperative medical clearance.

DVT / Pulmonary emboli

  • Incidence: PE=0.41% (SooHoo NF, JBJS 2006;88:480)
  • Without anticoagulation therapy, as many as 80% will show asymptomatic DVT by radiographic criteria; 8% asymptomatic PE; Fatal PE < 1%. (Simon SR, Ortho Basic Science, 2nd p310)
  • see DVT

Patella Fracture

  • Goldberg Classification: Type I=avulsion fx, generally involving the periphery of the patella but not the implant, cement, or quadriceps mechanism. Type II: cement-prosthesis interfaces disrupted or the quadriceps mechanism. Type III-A: involve the inferior pole of the patella with disruption of the patellar ligament. Type III-B: nondisplaced fractures of the inferior pole of the patella with an intact patellar ligament. Type IV: fracture-dislocations of the patella. (Goldberg VM, CORR 1988;236:115)
  • Treatment: Nondisplaced (<1cm) = cylinder cast 6-8 weeks. Transverse displased >1cm, or >30 degree extensor lag = ORIF. Displaced avulsion fractures of proximal or distal pole with an intact patellar component = repair with heavy nonabsorbable sutures passed through the quadriceps tendon or patellar tendon and secured to the patella through drill holes. Comminuted with stable prosthesis, regardless of the extent of fragment displacement = cylinder cast. Comminuted with prosthesis-patella disruption = patellectomy. (Lonner JH, JAAOS 1999;7:311).

Component Loosening

  • Patellar component: 1%. Symptoms vary from painless effusion to retropatellar pain, clicking, or instability. Treatment = revision of patellar component (mixed results, with high complication rates)
  • Tibial Component: Measured using The Knee Society scoring system. A/P view has 7 zones 1-4 along tibial cut from med to lateral. 5-7 along stem from med to lat. LAteral view has 1-5 zones from ant to post along stem. (Ewald FC, CORR 1989;248:13). Evaluate for radiolucent lines / migration / osteolysis.

Tibial Tray Wear

Peroneal Nerve Palsy

  • Incidence: 0.3% to 2%
  • Risk Factors: flexion contracture, valgus deformity, prior knee surgery(HTO)
  • Treatment: Removal of all constrictive dressings and repositioning of the knee in 20 to 30 degrees of flexion. Plantigrade anklefoot orthosis and stretching should start immediately to prevent equinus contracture. Consider EMG/NCV if no recovery is noted at 2 months. If there is no recovery of nerve function by 3 months, neurolysis may be indicated.

Periprosthetic Femoral Fracture

  • Incidence:
  • Risk Factors: Advanced osteoporosis, neurologic disorders, rheumatoid arthritis, chronic corticosteroid therapy.
  • Femoral Notching: Notching decreases femoral bending strength by 18% and torsional strength by 39.2% (Lesh ML, JBJS 2000;82:1096). But notching has not been shown to increase fracture risk or change clinical outcomes (Ritter MA, JBJS 2005;87:2411).
  • Treatment:
    -Type IA(nondisplaced, stable prosthesis, good bone stock) = conservative
    -Type IB(displaced, stable prosthesis, good bone stock) = ORIF locked plates or retrograde femoral nail
    -Type II (malpostioned or loose prosthesis, adequate bone stock) = revision arthroplasty
    -Type III (malpositioned or loose prosthesis, poor bone stock) = allograft prosthetic composite or modular hinged implant distal femoral replacement (Kim KI, CORR 2006;446:167).

Periprosthetic Tibial Fracture

Wound Complications / Skin Slough

  • Risk Factors: prior knee incisions, inflammatory arthritis, malnutrition, immunosuppressive drugs.
  • Prevention: Discontinue immunosuppressive drugs (methotrexate) preoperatively if possible, Nutritional supplementation for patients with a serum albumin level <3.5 g/dL and a total lymphocyte count <1,500/mm3.
  • Treatment: Dependent on wound conditions. Full-thickness skin necrosis = debridement and rotational gastrocnemius flap coverage. (Greenber B, Plast Reconstr Surg 1989;83;85)

Patellar Clunk Syndrome

  • Painful catching sensation when the extensor mechanism travels over the trochlear notch as the knee extends from 45 degrees of flexion to 30 degreess from full extension.  Snapping, pain, crepitus, and sometimes secondary patellar instability from a fibrous nodule or proliferative synovium that forms at the insertion of the quadriceps tendon. (Hozack WJ, OCRR 1989;241:203)
  • Occurs almost exclusively with posteriorly stabilized implants.
  • Prevention: When a posteriorly stabilized knee prosthesis is used, the peripatellar synovium around the quadriceps tendon insertion should be excised.
  • Treatment: Arthroscopic debridement with excision of hypertrophic tissue. (Lucas TS, CORR 1999;367:226).  Recurrence is uncommon
  • Dajani KA, J Arthroplasty 2010 Jan;25:97-103

Patellofemoral Instability

  • Patellar maltracking manifests as: tilting, subluxation, or dislocation.
  • Incidence: from 0.5% to as high as 29%. (Lonner JH, JAAOS 1999;7:311).
  • Etiology: component design, extensor mechanism imbalance, asymmetric patellar resection, malrotation of the femoral or tibial component, or patellar malpositioning.
  • Prevention: Restore normal Q-angle; Place femoral component perpendicular to the mechanical axis, with enough external rotation to establish a rectangular flexion gap and facilitate patellar tracking; Femoral component should be appropriately sized in the A/P dimension to avoid overstuffing; recreat patellar thickness; tibial component should be centered with the medial third of the tibial tubercle; Perform lateral retinacular release in patella subluxates laterally during "NO Thumbs" ROM evaluation.
  • Component position can be assess with Axial CT views from the supracondylar distal femur to the proximal tibia below the tibial tubercle.
  • Treatment: Lateral release, correct any component malpositioning.


  • Incidence:
  • Generally occurs in flexion.
  • Etiology:excessive recession or delayed incompetence of the posterior cruciate ligament in cruciate-retaining prostheses, excessive resection of the posterior femoral condyles, asymmetry of the flexion space, incompetence of the medial collateral ligament, overzealous soft-tissue release.
  • Treatment: revision to correct underlying cause.

Popliteal Artery Injury

  • Incidence: 0.03% (Rand JA, J Arthroplasty 1987;2:89)
  • Risk Factors: preexisting arteriosclerotic disease, correction of extensive flexion contractures.
  • Prevention: gentle posterior retraction, ensure posterior capsule is not violated.
  • Treatment: Vascular surgery consultation, ligature of small branches, primary repair, or interpositional grafting.

Quadriceps Tendon Rupture

  • Incidence: 0.1% (Dobbs JBJS 2005;87A:37)
  • Treatment: Partial tears = nonoperative treatment. Complete tears = surgical repair. Complication rate with surgical repair is high.

Patellar Tendon Rupture

  • Incidence: 0.17% to 1.45% (Lonner JH, JAAOS 1999;7:311).
  • Etiology: Intraoperative tendon avulsion off the tibial tubercle due to excessive tension during exposure.
  • Risks: patellar baja, pre-operative flexion contracture.
  • Prevention: Consider quadriceps V-plasty, quadriceps snip, or tibial tubercle osteotomy in at risk cases or placing a pin into the distal patellar tendon insertion to prevent avulsing.
  • Treatment: If <30% primary repair of the medial capsuloretinacular sleevewith normal postoperative PT. Complete avulsions = repair with semitendinosis autograft augmentation (Cadambi A JBJS 1992;74A;974).


  • The best predictor of postoperative ROM is the preoperative ROM.
  • A patient with 90° of flexion and within 10° of full extension and no pain does not have a stiff knee. 
  • Post-operative stiffness usually subsides within 6-8wks.  ROM generally improves steadily during first 3 months after surgery, after which less rapid progress may be seen for an additional 9 months or more. 
  • Etiology:infection, CRPS, component malposition, mechanical malalignment, etc.
  • Treatment: Closed manipulation (27570 Manipulation of knee joint) is most successful within the first 3 months after total knee arthroplasty. Arthroscopic (29884 knee arthroscopy with lysis of adhesions) or modified open lysis of adhesions can be considered after 3 months. Revision arthroplasty is preferred for  stiffness from malpositioned or oversized components. Patients who initially achieve adequate range of motion (>90° of flexion) but subsequently develop stiffness more than 3 months after surgery should be assessed for intrinsic as well as extrinsic causes. (Kim JAAOS 2004;12:164-171). Pre-operative work-up should rule-out infection.
  • Revision TKA for stiffness without clearly identified cause has poor results. 

Fat Embolism

  • Associated with the use of intramedullary guide systems and bilateral TKA
  • Prevention: suction canal before placing intramedullary guide. Guides should be fluted and entrance hole should be larger then the intramedullary guide
  • see also Fat Embolism Syndrome

MCL Rupture

  • Consider semitendinosus autograft or Achilles allograft reconstruction (Peters CL, J Arthroplasty 2004;19:935).

TKA Complications Review References

  • Lonner JH, JAAOS 1999;7:311
  • Ayers DC, JBJS 1997;79A:287