Patella Fractures: Approach to Treatment

Damayea I. Hargett, MD; Brent R. Sanderson, DO; Milton T.M. Little, MD

Disclosures

J Am Acad Orthop Surg. 2021;29(6):244-253. 

In This Article

Management of Inferior Pole Patella Fractures (Including Partial Patellectomy)

Inferior pole patella fractures are complex injuries due to the degree of comminution that often limits standard fixation techniques. Heterogeneity of patients and patella fractures in the current literature limits definitive conclusions when comparing open reduction and internal fixation with partial patellectomy. Reconstructable inferior pole fractures may be addressed with plate fixation, suture fixation, and suture anchor fixation.

Matejčić et al[42] evaluated the basket plate in the treatment of comminuted fractures of the distal pole of the patella. It showed excellent functional outcomes in 81% of patients and good results in the other 18%. In addition, minifragment fixation can be used for fixation of inferior pole fractures that are reconstructable (Figure 4). The goal of fixation is to restore inferior pole alignment while avoiding patellar baja, which may result with inferior pole patellectomy.

Figure 4.

One-year postoperative (A) AP and (B) lateral radiographs of 62-year-old woman displaying a minifragment T-plate with a free cancellous screw fixation construct.

Suture fixation for management of inferior pole comminution uses nonabsorbable braided sutures passed through the patellar tendon in a Krakow fashion then passed through the inferior pole comminution.[43] These sutures can then be passed through intraosseous tunnels in the patella and tied over the superior pole of the patella (Figure 5). When comparing this technique to tension band wiring for inferior pole comminution, 7.6% of patients required reoperation in the suture fixation cohort compared with 30.6% of patients in the tension band wiring cohort. A similar technique using suture anchors was described by Kadar et al.[44] They were able to demonstrate similar results to partial patellectomy. Inferior pole fixation is critical to appropriately align the inferior pole because malunion can result in impingement and anterior knee pain. Current literature favors the use of nonabsorbable suture compared with metal fixation to decrease the risk of hardware complications; however, future research remains warranted.[43,44]

Figure 5.

(A) AP and (B) lateral radiographs of 65-year-old woman with inferior pole fracture. One-year postoperative (C) AP and (D) lateral radiographs demonstrating union of an all suture fixation construct for an inferior pole patella fracture.

Partial patellectomy should be considered for highly comminuted inferior pole patella fractures where anatomic reduction cannot be achieved through the above mentioned techniques. Whether poor bone quality or complexity of fragmentation preclude fixation, the goals of treatment shift to the retention of a stable portion of the patella to maintain a well-functioning extensor mechanism. Partial patellectomy alters the extensor mechanism by decreasing the lever arm about the knee joint, resulting in up to 33% of patients with abnormal patellar tilting and 42% of patients with patella baja.[45] Anterior reattachment of the patellar tendon to the patella remnant is recommended to minimize the patellofemoral contact stresses.[46] Satisfactory clinical results have been shown with maintenance of at least 60% of the patella, with a notable increase in resulting patellofemoral contact forces.[47] Partial patellectomy has dramatic effects on the patellofemoral mechanics, with up to 55% of patients developing osteoarthritic changes at the 2-year follow-up.[45,46]

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