Total Knee Arthroplasty Without Reduction of the Patella for Genu Valgum With Permanent Dislocation of the Patella: A Case of Nail Patella Syndrome

A Crossed Screw Patellar Reconstruction Technique for the Treatment of the Severely Deficient Scaphoid Shaped Patella in Total Knee Arthroplasty

One of the contraindications to patella resurfacing in total knee arthroplasty is a thin and severely eroded 'deficient' patella. However, such patients often present with severe patellofemoral joint arthritis, patellar lateral subluxation, and patella maltracking, which can only be treated effectively with resurfacing. While various treatments have been proposed, options remain limited. Here we introduce a method of patella reconstruction using four 2.7-mm titanium cortical screws crossing each other into the inner shell of the patella. This provides a scaffold onto which bone cement and any standard polyethylene patellar component can be fixed. Postoperatively, the patient had no anterior knee pain, no patella maltracking, and no component loosening. Advantages of this technique include minimization of extensor disruption, low costs, easy accessibility, reproducibility, and improved mechanical strength.

"Knee-Ding" a Diagnosis: A Case of Nail Patella Syndrome

Nail Patella Syndrome (NPS) is a rare genetic disorder with pathognomonic signs including dystrophic fingernails, iliac horns, and limb abnormalities, which commonly include hypoplastic development of the patellae, causing patients to experience patellar instability. This resulting patellar instability increases susceptibility to recurrent subluxations or dislocations in NPS patients. Since these anatomical abnormalities are present at birth or in childhood, early recognition may prevent the need for surgical intervention if appropriate preventive measures are taken. This case report describes a 54-year-old woman with a history of NPS, diagnosed later in adulthood, with a prior patellectomy at age 18 secondary to an unspecified left knee injury that occurred at age 4. A combination of radiographic and clinical findings are presented, which support the diagnosis of NPS, including dystrophic nails, left knee x-ray consistent with prior patellectomy, and right knee x-ray showing inferolateral subluxation of a hypoplastic patella. Additional signs associated with NPS are also discussed, including mood disorders, Raynaud's, and a high hairline which may assist in early diagnosis. This case report emphasizes earlier identification of NPS by clinicians through recognition of signs and symptoms while also considering proactive measures to lessen recurrent subluxations or dislocations to preserve patellar integrity and reduce the need for surgical intervention.