Comparison of two total knee prostheses on the incidence of patella clunk syndrome

Abstract

The patella clunk syndrome is not an uncommon complication, particularly after posterior-stabilized (PS) total knee arthroplasty. The present study was a consecutive unselected series comparing the incidence of the patella clunk syndrome amongst two comparable groups of elderly patients with knee arthritis implanted with the Insall-Burstein (IB II) total knee system and the newer NexGen Legacy total knee prosthesis. While 7.5% of patients in the PS IB II group developed patella clunk syndrome, none occurred in the NexGen group (P=0.05). We believe the difference is due mainly to a change in the design of the prosthesis, especially the more posterior intercondylar box and femoral cam of the NexGen femoral component.Résumé Le ressaut patellaire audible (clunk syndrome) n'est pas une complication rare en particulier après arthroplastie total du genou postéro -stabilisée (PS). La présente étude est celle d'une série consécutive de patients non sélectionnés comparant la fréquence de ce syndrome parmi deux groupes comparables de malades âgés avec arthrose du genou traités par prothèse de Insall-Bustein (IB II) ou par prothèse NexGen Legacy. Pendant que 7.5% de malades avaient un «clunk syndrome» dans le groupe IB II, aucun ne s'est produit dans le groupe NexGen (P=0.05). Nous croyons que la différence est principalement due à un changement dans le dessin de la prothèse, notamment un boitier intercondylien et une came fémorale plus postérieurs pour la prothèse Nexgen.

Patello-femoral clunk syndrome-current concepts

“…In either case, the altered patellofemoral kinematics may be in part responsible for the development of patellar clunk syndrome. 2 The effect of increased knee flexion achieved with the MIS approach, which resulted in an increase in patella clunk, Patellar crepitus and clunk syndrome have also been attributed to abnormal patellar tracking secondary to inadequate soft-tissue balance or tibial component malrotation and mal tracking of the patella. 12 In patients with/without pre-op PF pain, the incidence of postop PF pain, clunk and crepitus is lower in patients who underwent patelloplasty.…”

“…It is concluded that both the height and the width of the intercondylar box were design features leading to synovial entrapment. 2 The incidence of patellofemoral complications in patients with PS TKAs has long been attributed to patellar baja and anterior placement of the tibial tray. A lower Insall-Salvati ratio, lower patellar component height, lower position of the proximal pole of the patella, and anteriorization of the tibial tray were all associated with a higher incidence of patellar clunk syndrome.…”

“…Nevertheless, prevention is preferred. 2 The design of a total knee prosthesis has a strong bearing on the incidence of the patella clunk syndrome. 9 Femoral components with a deep trochlear groove and smooth transition of the intercondylar box appear to better accommodate any peripatellar fibrous nodule that may form after total knee arthroplasty.…”

“…1 Patella clunk syndrome is a syndrome of patellofemoral dysfunction, consisting of painful catching, grinding, or jumping of the patella on knee extension, and is a well-recognized complication after total knee arthroplasty. 2 Patellar clunk syndrome is characterized by the formation of a fibrous nodule at the articular side of junction of superior pole of patella and the quadriceps tendon. 3 They are primarily associated with implantation of posterior cruciate substituting designs.…”

“…1 The patella clunk syndrome irrespective of whether or not the patella was Resurfaced. 2 The patients with soft-tissue impingement under the patella into 3 groups: (I) patellar clunk syndrome, the isolated fibrous nodule located in the suprapatellar lesion without the other fibrous tissues causing the impingement (II) impinging hypertrophic synovitis, generalized hypertrophic synovitis with no fibrous nodule; and (III) the combination of types I and II, the suprapatellar fibrous nodule with generalized hypertrophic synovitis. 5 The Press Fit Condylar Cruciate sacrificing prosthesis is more likely to be associated with the patellar clunk syndrome.…”