Painful TKA ICD-9
Painful TKA Etiology / Epidemiology / Natural History
- Meta-analysis of 9,879 TKA; average of 4.1 years’ follow-up; 89.3% good or excellent result, 10.7% fair or poor; 3.8% underwent revision TKA. (Callahan CM, Drake BG, Heck DA, Dittus RS: Patient outcomes following tricompartmental total knee replacement: A meta-analysis. JAMA 1994;271: 1349–1357)
- Painful TKA can be related to pain, stiffness, and or instability as well as alternative etiologies (see differential diagnosis below)
Painful TKA Anatomy
Painful TKA Clinical Evaluation
- Evaluate for varus or valgus thrust
- Internally rotated tibial component leads to an externally rotated foot progression.
- Evaluate PCL-retaining TKAs for PCL insufficiency: posterior tibial sag, a positive posterior drawer test, and a positive 90° quadriceps active test. Treatment = arthroscopic excision. (Beight JL, . Clin Orthop 1994;299: 139)
Painful TKA Xray / Diagnositc Tests
- Review prior records, operative report, imaging.
- Knee AP weight bearing, lateral and sunrise views. Beam should be parallel to tibial baseplate. Femoral component: 4°-7° of valgus, anterior flange in contact with anterior cortex. Tibial component: perpendicular to long axis of the tibia on AP view and perpendicular or sloped < 10° on lateral view. Evaluate for periosteal reaction, scattered foci of osteolysis, bone resoprtion, implant wear, progressive radiolucencies, osteopenia,
- Loosening: change in position noted on sequential radiographs, a radiolucent line extending under the entire prosthesis, progressive widening of the cement-bone or bone-prosthesis interface, lucencies at the metal-cement interface, cement cracking or fragmentation. Incomplete, non-progressive radiolucencies are not considered pathologic
- Bone Scan: sensitivity = 33%, specificity = 86%, positive predictive value = 30%, negative predictive value = 88%. (Levitsky KA, J Arthroplasty. 1991;6:237)
- ESR (Westergen erthrocyte sedimentation rate): rises normally after total joint surgery. Returns to normal 6 weeks after surgery. Infection suggested if elevated 3 months after surgery.
- CRP (C-reactive protein): Rises normally after total joint surgery. Returns to normal @3weeks after surgery. Infection suggested if elevated 3 months after surgery.
- Interleukin-6 (IL-6): Rises normally after total joint surgery. Returns to normal within 48 hours after surgery. Elevated (>10 pg/mL [>10 ng/L]) in patients with periprosthetic infection.
- Aspiration of Joint fluid: send for aerobic culture anaerobic culture, sensitivities, Gram stain, acid-fast staining, CBC with differential. Leukocyte count > 1.7x109/L indicates infection.
- Leukocyte esterase reagent strips: Moderate or large WBC on strips indicates infection. Sensitivity=92.9%, specificity=88.8%. Blood or debris in synovial fluid renders the strips unreadable in 1/3 of cases. (Parvizi, J, AAHKS annual meeting 2011).
Painful TKA Classification / Treatment
- Instability: may be related to Quad weakness
- Pain: common causes: loosening and component failure, patellar dysfunction, limb deformity, infection. Less common causes: neuroma, CRPS, bursitis, referred pain.
- Pain in full extension: overstuffed extension space.
- Pain with full flexion: impingement between a posterior femoral osteophyte and the tibial component, or overstuffing of the flexion space.
- Pain with stairs: dysfunction of the extensor mechanism.
- Pain with activity: loosening and component failure.
- Patellar Clunk: audible popping as the knee moves from flexion to extension due to a nodule or mass just superior to the patellar tendon. Treatment = arthroscopic excision. (Beight JL, Clin Orthop 1994;299: 139)
- Loosening / Osteolysis: new onset of pain or effusion, effusion, crepitus, grinding of the knee, rarely, skin staining from metal fretting and debris. Treatment = revision
Painful TKA Associated Injuries / Differential Diagnosis
- Disk herniation
- Spinal stenosis
- Vascular claudication
- Psychosomatic illness
- Hip osteoarthritis
- Postphlebitic syndrome
- Diabetic neuropathic pain
- Superficial neuroma
- Pes Anserine bursitis
Painful TKA Complications
Painful TKA Follow-up Care
Painful TKA Review References