The Management of Patients with Painful Total Knee Replacement

Reviewed by Dr Emily Kong MBBS | Accredited Orthopaedic Registrar

  • The management of patients with painful total knee replacement
    • Although TKR is effective operation for OA, symptoms may persist post op
    • Management should have a multidisciplinary approach:
      • Diagnosis + Investigation
      • Pain Management
      • Support
    • Treatment and identify intrinsic and extrinsic causes of painful TKR early
    • Involve patient’s GP
    • Unrelieved acute severe pain can exacerbate pts pre-op tendency for anxiety, depression, hostility and pre-occupation with health
    • Early attempts to relieve pain may avoid development of chronic states

Management of Pain

  • Pain post TKR may increase or fail to improve:
    • Regular pre-op analgesia ceased
    • Physio input decreased
  • Encourage regular analgesia
  • Consider oral or topical options:
    • Sustained released orals
    • Transdermal patches

Management of Neuropathic Pain

  • Clinical Assessment:
    • Dysaesthesia
    • Allodynia
    • Pain assoc. with non-noxious stimuli
    • Hyperalgesia
    • Spontaneous pain
  • Treatment options
    • Capsaicin cream
    • 5% lignocaine plasters:
      • Trial for 2 weeks
    • Regular massage of scar
    • Tricyclic antidepressants:
      • Dual effect: relief from anxiety +/depression
    • Anticonvulsants:
      • Gabapentin, pregabalin

Management of Painful Neuroma

  • Trail conservative therapy 1st
  • Consider resection after 6 months
  • Positive response to local anaesthetic blocks crucial in identifying benefits from surgery
  • Selective denervation of nerve:
    • Satisfaction rate up to 86%
  • High incidence of post op hypersensitivity (40%):
    • Usually self limiting within 6wks

Management of CRPS

  • Prospective study prevalence:
    • 21% one month
    • 13% three months
    • 12.7% three months
  • Risk factors:
    • Pre-operative pain
    • Distress
  • Symptoms include:
    • Diffuse skin, joint and musc. pain
    • Sensory disturbances
    • Neuropathic pain
  • Signs and symptoms spread beyond the knee
    • Beware of pain at rest
    • Difficulty moving a mechanically sound TKR
    • Analgesics should be introduced early to allow pts to participate in rehab and desensitisation programs
    • Sympathetic blocks are generally not helpful:
      • Should be reserved for those with clinical symptoms of sympathetically-mediated pain
    • Success to Treatment is early Diagnosis and Management
    • Prognosis variable:
      • 50% develop chronic symptoms
    • When managed early, long term prognosis similar to uncomplicated TKR at 54mths

Infection

  • Goals of Treatment :
    • Eradication of infection
    • Alleviation of pain
    • Recovery of function
  • Variables:
    • Superficial or deep infection
    • Duration since surgery
    • Host factors
    • Soft tissue around knee
    • Organism
  • Treatment options:
    • ABx suppression
    • Arthroscopic or open debridement
    • One or Two-staged revision
    • Arthrodesis
    • Amputation

Instability

  • Unstable TKR causes pain due to abnormal stressors on knee and soft tissues
  • Ascertain nature of instability:
    • Quads weakness
    • Flexion contracture
    • PF maltracking
    • Pain
  • Early instability:
    • Uncorrected pre-op ligamentous imbalance
    • Improper intra-op ligamentous imbalancing
    • Flexion-extension mismatch
    • Iatrogenic collateral ligament damage
    • Pre-existing neuromuscular pathology
  • Late instability:
    • 2° to malalignment causing ligament stretching
    • Polyethylene wear
    • Loosening
    • Collapse
  • Management is difficult:
    • Weight loss
    • Correction of hip/foot/extra-articular deformities
    • Ligament reconstruction + constrained prosthesis
    • Revision to hinged prosthesis
    • Arthrodesis

Extensor Mechanism Problems

  • Common cause of pain and dissatisfaction post-op:
    • PF maltracking + instability
    • Extensor mechanism disruption
    • Patellar clunk syndrome
    • Peri-patellar adhesions
    • Polyethylene wear
    • Osteonecrosis
  • PF instability:
    • Incidence of sublux/disloc.
      • previously 10-35%
    • Newer prosthetic designs <1%
    • Can be 2° to:
      • Malrotation of implant
      • Overstuffing PFJ
      • Tissue imbalance
      • Asymmetrical resection of patella
    • Management
      • Conservative Management not usually helpful:
      • VMO strengthening
      • Bracing
      • Mainstay of Treatment is surgical
      • Malrotation of components:
        • Difficult to address without revision of one or both components
        • If components correct, lateral retinacular release may improve PF tracking, but can cause complications:
          • Wound healing
          • AVN of patella or Fracture
          • Post-op pain + swelling
          • Slower rehab
  • Rupture of patellar tendon:
    • Uncommon: incidence 0.12%
    • Partial avulsion can be reattached primarily
    • Reinforcement with autograft or synthetic graft
    • Extensor lag +/restricted ROM may persist
  • Quadriceps tendon rupture:
    • Uncommon: incidence 1.1%
    • Risk factors:
      • Quads turn down
      • Over-resection of patella +/patellar tendon damage
      • Extensive lateral release
      • Requires direct repair
  • Periprosthetic Fracture of Patella
    • Incidence 1-2%
    • Predisposing factors:
      • Lateral release
      • Excessive resection of bone
      • Single peg fInvestigationation
      • Patella maltracking
      • Malposition of implant
    • Management depends on:
      • Location
      • Pattern of Fracture
      • Extensor mechanism integrity
      • Stability of implant
      • Quality of bone
    • Conservative Management:
      • No extensor mechanism disruption
      • No loosening of component
      • No major malalignment
    • Surgical Management:
      • Disruption of extensor mechanism
      • Dislocation of patella
      • Unstable implants
    • Ortiguera and Berry Classification + Treatment :
      • Type I: Stable implant, intact ext mech.
        • Conservative Treatment
      • Type II: Intact implant + ruptured ext mech.
        • Ext mech. repair + partial patellectomy or ORIF
      • Type IIIa: Loose patella, good bone
        • Revision component or resection arthroplasty
      • Type IIIb: Loose patella, poor bone
        • Removal of implant + patelloplasty/total patellectomy

Stiffness

  • Incidence not well described:
    • 3% to 60%
  • Common presenting complaint
  • Can lead to pain and functional limitation
  • Difficult to define:
    • Need to clarify what pt is happy or unhappy about
  • Contributing factors:
    • Poor pre-op ROM
    • Previous knee surgery
    • Infection
    • Technical errors: over stuffing, imbalancing, malrotation, elevation of joint line
    • CRPS
    • Severe post-op pain preventing rehab
  • Treatment options:
    • Intense physio
    • MUA
    • Arthroscopic or open arthrolysis
    • Revision
  • MUA:
    • Risks: Fracture, rupture PT, wound breakdown, haemarthrosis
    • Rehab post manipulation critical to success
    • Analgesia
    • Timing:
      • 2 weeks Vs 6 weeks
      • Delaying factors: haematoma, medical Cx
  • Arthroscopic release:
    • May be beneficial at 3-6mths post op in well-balanced knee
    • Very stiff knee may break instruments
    • May be able to assess contributing factors to stiffness

Impingement

  • Popliteus Tendon:
    • Difficult to diagnose
    • Treatment arthroscopic release
  • Fabellar:
    • Consider in pts with discrete posterolateral pain and large fabella
    • Pain often activity-related
    • Impinges on femoral or tibial component
    • Treatment excision

Patellar Clunk Syndrome

  • Incidence up to 3.5%
  • Three main groups:
    • Isolated fibrous nodule located in suprapatellar region
    • Impinging hypertrophic synovitis, generalised hypertrophic synovitis with no fibrous nodule
    • Combination of the above
  • Excellent results with arthroscopic resection

Recurrent Haemarthrosis

  • In absence of bleeding disorder, is due to impingement of proliferative synovium
  • Often treated conservatively
  • Surgical Treatment successful:
    • Arthroscopic or open synovectomy
    • Surgical embolisation

Role of Arthroscopy in Painful TKR

  • Good for Treatment of:
    • Soft tissue impingement
    • Arthrofibrosis
    • Loose body
    • Acute infection
  • Recommend 24-48hrs prophylactic ABx
  • Care not to scratch implants wear debris

Unexplained Pain

  • Incidence at 1 year up to 18.2%
  • Series of 622 pts:
    • 4% unexplained pain
    • 55.5% improvement without intervention
  • Revision results in these pts unpredictable

Other potential causes of a painful TKR and how to avoid them

  • Incision site:(1)
    • Avoid skin incisions too far medially: causes large lateral skin flaps and potential increased rate of wound complication
    • Placement of the skin incision slightly lateral to the midline can assist in eversion of the patellar, especially in obese pts
    • Layered wound closure without tension to minimize risk of wound necrosis
  • Tourniquet:(3)
    • May not influence the satisfaction post operatively based on a pt questionnaire
    • Pain scores not significantly different between tourniquet Vs no tourniquet
  • Haemostasis before closure:(1)
    • Meticulous wound haemostasis is required to avoid a post operative haematoma
    • Pain may be increased from pressure caused by a large haematoma
  • Cement Vs Uncemented:(2, 4)
    • Start up pain occurs with initial wt bearing and improves after a few steps: following cemented arthroplasty – lasts 4-6wks, cementless – 3-4mths because micromotion is present until ingrowth occurs
    • Localised tenderness/pain of tibial component may occur due to incomplete cementation
    • Pain from loosening of a cemented femoral component may be due to inaccurate bony cuts, poor cement technique and deficient bone
    • Avoid cementing onto sclerotic bone
    • Defects in cement mantle can act as channels for passage of polyethylene debris into bone-cement mantle allows for osteolysis
    • Pain associated with loosening of cementless TKRs may be due to incomplete porous coating, screw holes and incomplete bony ingrowth
  • Patient-related risk factors:(1)
    • Long term steroid use can delay/impair wound healing
    • Obesity: difficulty with exposure, excessive retraction of wound, larger incision, thick layer of adipose tissue therefore skin less adherent to vascular supply increasing chances of necrosis
    • Malnutrition
    • Smoking
    • Diabetes
    • Peripheral vascular disease can cause delayed wound healing: hypovolaemia intra-op can reduce oxygen delivery to operative site

Take home message

  • Difficult problem – multifactorial
  • Needs multidisciplinary approach
  • Identify and treat cause promptly – delay may lead to chronicity
  • If no cause can be found despite extensive Investigation, revision surgery should be performed with caution:
    • Low success rate
    • More than 50% may improve with conservative Treatment alone

References

  1. D. Ayers, D. Dennis, N. Johanson, V. Pellegrini, Jr Instructional Course Lectures, The American Academy of Orthopaedic Surgeons – Common Complications of Total Knee Arthroplasty J Bone Joint Surg Am 1997;79:278-311
  2. M. Gonzalez, A. Mekhail The Failed Total Knee Arthroplasty: Evaluation and Etiology J Am Acad Orthop Surg 2004;12:436-446
  3. P.Baker, J. van der Meulen, J. Lewsey, P. Gregg The role of pain and function in determining patient satisfaction after total knee replacement J Bone Joint Surg Br 2007;89-B:893-900
  4. V. Mandalia, K. Eyres, P. Schranz, A. Toms Evaluation of patients with a painful total knee replacement J Bone Joint Surg Br 2008;90-B:265-71