title: Total knee arthroplasty using trochlear groove as guide for position of femoral component in severe knee osteoarthritis.
abstract: BACKGROUND
  Apart from transepicondylar axis, the native femoral sulcus was also reported to be used as a guide for the femoral component position in total knee arthroplasty (TKA). However, it was not shown in patients with severe knee osteoarthritis. This study was conducted to compare the position of trochlear groove in patients with and without osteoarthritis, and to assess whether trochlear groove could be used as a guide for position of femoral component in TKA for severe knee osteoarthritis.
  
  
  METHODS
  Total 50 severe knee osteoarthritis patients (Kellgren Lawrence grade 3 or 4) who underwent TKA were included. Meanwhile, 50 patients who underwent arthroscopic surgery without osteoarthritis were included as control. The distance from trochlear groove to the midpoint of a virtual anterior condyle osteotomy line (parallel to the posterior condyle line) (a-b) was recorded by radiological and surgical measurements. Midpoint of transepicondylar axis and trochlear groove were used as guide for placing prosthesis model in TKA, respectively. No-thumb test was performed to assess the patellar tracking. The position of femoral component was finally performed using trochlear groove as guide in TKA.
  
  
  RESULTS
  Value of "a-b" was significantly different between osteoarthritic and control knees (P = 0.008). During the placement of prosthesis model, similar patellar tracking was detected between using midpoint of transepicondylar axis and trochlear groove as guide (P > 0.05). After placing femoral component using trochlear groove as guide, most patients obtained good patellofemoral congruence with pneumatic tourniquet inflated (n = 43) or deflated (n = 5), and good patellofemoral congruence was also obtained by lateral patellar retinaculum release in two patients.
  
  
  CONCLUSIONS
  Despite the shifting of trochlear groove caused by severe knee osteoarthritis, trochlear groove can be used as a guide for position of femoral component, with equivalent patellar tracking compared with transepicondylar axis.
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Gangyong
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China. dr.xiajun@139.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Xia
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Siqun
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Feiyan
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Fudan University, 12th Wulumuqi Middle Road, Shanghai, 200040, China.
authors.forename: Jingsheng
authors.initials: J
authors.lastname: Shi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D015331:Cohort Studies; D005260:Female; D005269:Femur / Q000033:anatomy & histology* / Q000601:surgery; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D010027:Osteotomy; D010329:Patella / Q000033:anatomy & histology; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Knee osteoarthritis; Patellar tracking; Prosthesis; Total knee arthroplasty; Trochlear groove