Does the Kinematch® Prosthesis Impair Knee Flexion in Patients with Trochlear Dysplasia?


  • Ronald Grelsamer, MD
  • Paul Cavallaro, BS



Background: Patellofemoral replacements are used to treat isolated patellofemoral arthritis in carefully selected patients. The Kinematch® custom-designed implant is placed directly on subchondral bone, leading critics of the device to believe that this results in overstuffing and limitation of flexion in cases of trochlear dysplasia; the current study aims to evaluate this premise.

Methods: A retrospective analysis of a consecutive series of 24 patients (32 knees) was conducted.  Trochlear dysplasia was evaluated using pre-operative axial CT scans, and knees were categorized as having minimal or moderate/severe dysplasia (moderate = flat trochlea, severe = convex trochlea). The primary outcome was post-operative knee flexion.

Results: There was no statistical or clinical difference in post-operative knee flexion between the minimal (120°+12) and the moderate/severe dysplasia (117°+9) groups (p=.34).  

Conclusions: Use of the Kinematch® patient-specific custom trochlear component does not significantly limit flexion in cases of trochlear dysplasia, and although the surgeon has the ability to deepen the trochlea by way of the pre-operative model, this is not necessary. 

Keywords: Patellofemoral replacement; custom; flexion; trochlear dysplasia

Level of Evidence: III, Case-control study


Sisto DJ, Sarin VK: Custom patellofemoral arthroplasty of the knee.J Bone Joint Surg (Am) 2006; 88(7):1475-80.

Lonner JH. Patellofemoral arthroplasty. J Am Acad Orthop Sur. 2007;15(8):495-506.

Ackroyd CE, Newman JH, Evans R, Eldridge JDJ, Joslin CC. The Avon patellofemoral arthroplasty. J Bone Joint Surg, (Br). 2007;89-B(3):310-315.

Sisto DJ, Grelsamer RP, Sarin VK. Patient-Specific Patellofemoral Arthroplasty. In: Fokter SK ed. Recent Advances in Hip and Knee Arthroplasty. InTech, 2012: 302-314.

Argenson JA, Flecher X, Parratte S, Aubaniac JM. Patellofemoral arthroplasty: An update. Clin Orthop. 2005;440:50-53.

Grelsamer RP, Stein D: Patellofemoral Arthritis. Current Concepts Review. J Bone Joint Surg. 2006; 88A:1849-1860.

Nicol SG, Loveridge JM, Weale AE, Ackroyd CE, Newman JH. Arthritis progression after patellofemoral joint replacement. The Knee. 2006;13(4):290-295.

Dejour D, Saggin P. The sulcus deepening trochleoplasty: the Lyon’s procedure. Int Orthop. 2010; 34; 311-316

Lippacher S, Dejour D, Elsharkawi M, et al. Observer agreement on the Dejour trochlear dysplasia classification. Am J Sports Med. 2012;40(4):837-843.

Lustig S, Magnussen R, Dahm D, Parker D. Patellofemoral arthroplasty, where are we today?. Knee Surg Sports Traumatol Arthrosc. 2012; 20(7):1216-1226.

Lonner JH: Patellofemoral Arthroplasty. 2010; Orthopedics. 33(9):653.

Hendrix MRG, Ackroyd CE, Lonner JH. Revision patellofemoral arthroplasty: Three- to seven-year follow-up. J Arthroplasty. 2008;23(7):977-983.

Pierson JL, Ritter MA, Keating EM, Faris PM, Meding JB, Berend ME, Davis KE. The Effect of Stuffing the Patellofemoral Compartment on the Outcome of Total Knee Arthroplasty. J Bone Joint Surg Am. 2007; 89(10): 2195-2203.

Dejour H, Walch G, Nove-Josserand L, Guier C. Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc. 1994; 2(1): 19-26.




How to Cite

Grelsamer, MD, R., & Cavallaro, BS, P. (2014). Does the Kinematch® Prosthesis Impair Knee Flexion in Patients with Trochlear Dysplasia?. Reconstructive Review, 4(1).



Original Article