Gap Non-union Patella Fractures: Case Report and Review of the Literature.

Introduction: Gap non-union patella fractures are rare but can be particularly challenging for the orthopedic surgeon. We report a case of a 12 cm gap non-union patella fracture in a patient with osteoporosis and its surgical management, functional outcome, and implications on clinical practice.

Case Report: A 73-year-old fully independent female with a background of osteoporosis was referred to our outpatient knee clinic. She reported a fall from stairs following an initial soft-tissue injury to the left knee 6 months prior. She has had progressive decline in mobility since the injury and was restricted to a wheelchair when she was seen in clinic. On examination, she had significant wasting of the quadriceps on the left side. Her range of movement was from 40° extensor lag to 90° flexion actively. Passive movements of the knee were preserved. She was unable to straight leg raise. Plain radiographs revealed a 12 cm gap non-union of her left patella. The patient was managed operatively in a two-staged approach. The first stage involved application of ring fixator device to achieve gradual skeletal traction from 5 to 12 lbs over a period of 10 days. The second stage involved conventional tension band wiring.

Conclusion: At 1-year follow-up, the patient achieved full independent mobility. This case highlights the efficacy of a two-staged approach in the management of gap non-union patella fractures in patients with poor bone quality.