Periprosthetic patellar fractures.

Periprosthetic patellar fractures represent a spectrum of injuries to a patient with a total knee arthroplasty. They range in severity from an inconsequential injury, which does not compromise function, to a severely debilitating injury that may require advanced reconstructive measures. This article will outline the epidemiology and risk factors associated with periprosthetic patellar fractures. Treatment options as they relate to injury mechanism, fracture severity, patellar component stability, and remaining bone stock will also be discussed. Finally, a review of the current literature regarding the results of treatment will be presented.

Periprosthetic distal femur fractures treated by retrograde intramedullary nails with a 10-degree distal bend achieve significantly better post-operative radiographic alignment when compared to conventional retrograde nails.

INTRODUCTION: Periprosthetic distal femur fractures (PPDFFs) are a common complication after total knee arthroplasty (TKA). In the setting of well-fixed TKA components, treatment options include retrograde intramedullary nailing (rIMN) or lateral locked plating. Treatment with rIMN has historically been associated with potential for extension deformity when using conventional nails. We hypothesized that the PPDFFs treated with an intramedullary nail with a specifically designed 10-degree distal bend for periprosthetic fractures would result in improved post-operative sagittal alignment compared to conventional intramedullary nails. MATERIALS AND METHODS: The study was conducted at a level-1 trauma center over a 12-year period (2010 - 2022). Patients over the age of 18 who sustained a PPDFF treated with rIMN were identified. The primary outcomes of the study were post-operative coronal and sagittal alignment determined by reviewing post-operative radiographs. RESULTS: A total of 50 patients were included. Twenty-three patients were treated with a rIMN with a 10° distal bend. Twenty-seven patients were treated with a rIMN with distal bend of 5° The mean aPDFA for the 10° distal bend group was 81.7° compared to 92.8° in the 5° distal bend group (p<0.001). There were 3/23 (13%) significant sagittal plane deformities the 10° distal bend group compared to 11/27 (41%) in the 5° distal bend group (p = 0.03). There was one patient with a post-operative extension deformity in the 10° distal bend group compared to 11 patients in the 5° distal bend group (p = 0.02). CONCLUSION: Retrograde intramedullary nailing of PPDFF with a 10° distal bend results in significantly better alignment in the sagittal plane when compared to a conventional 5° nail. The use of a 5° nail resulted in an extension deformity significantly more frequently. We therefore recommend the utilization of a rIMN with a 10° distal bend when treating PPDFFs. SUMMARY: Periprosthetic distal femur fractures are a common complication following total knee arthroplasty. While several studies report on the use of retrograde intramedullary nails in the treatment of periprosthetic distal femur fractures, there are limited reports of the use of a novel retrograde intramedullary nail with a 10° distal bend in the treatment of these injuries. Herein we present a radiographic study comparing coronal and sagittal postoperative alignment following treatment with retrograde intramedullary nails with a 10° distal bend versus conventional retrograde nails with a 5° distal bend.

Manipulation Under Anesthesia: A Safe and Effective Treatment for Posttraumatic Arthrofibrosis of the Knee.

OBJECTIVES: This study investigates the results of closed manipulations performed under anesthesia (MUA) to evaluate whether it is an effective means to treat posttraumatic knee arthrofibrosis. DESIGN: Retrospective review. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Twenty-two patients with a mean age of 40 underwent closed MUA for posttraumatic knee arthrofibrosis. Injuries included fractures of the femur, tibia, and patella as well as ligamentous injuries and traumatic arthrotomies. The mean time from treatment to manipulation was 90 days. Mean follow-up after manipulation was 7 months. INTERVENTION: Closed knee MUA. OUTCOME MEASUREMENTS: Improvement of knee range of motion (ROM) arc was the primary outcome. Patient demographics were correlated with manipulation success using a 2-sample t test. A delay in manipulation of 90 days or greater was also evaluated in this fashion with regard to its role in predicting the benefit of MUA. RESULTS: The mean premanipulation ROM arc was 59 ± 25 degrees. The mean intraoperative arc of motion, achieved at the time of the manipulation was 123 ± 14 degrees. No complications occurred during the MUA procedure. At the most recent follow-up, the mean ROM arc was 110 ± 19 degrees. Tobacco use, associated injuries, elevated body mass index, open fracture, and advanced age did not impact manipulation efficacy. Additionally, manipulations performed 90 days or more after surgical treatment provided a benefit equaling those performed more acutely (P = 0.12). DISCUSSION: MUA is a safe and effective method to increase knee ROM in the setting of posttraumatic arthrofibrosis. Improvement in ROM was noted in all patients. A 90-day window between fracture fixation and manipulation did not impact ROM at final follow-up and may prevent fracture displacement during the MUA. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.