Anterior Hook Plating of Patella Fractures: A Biomechanical Analysis and Clinical Series.

OBJECTIVES: To compare anterior hook plating with established fixation constructs biomechanically and report outcomes and complications in a cohort of patella fractures treated with the technique. DESIGN: Laboratory-based biomechanical study and clinical multicenter retrospective cohort study. SETTING: 2 US Level 1 trauma centers. PATIENTS/PARTICIPANTS: 51 patients (28 M and 23 F) with 30 simple transverse and 21 comminuted patella fractures. Thirty-six cadaveric patellae were used for the biomechanical study. INTERVENTION: Biomechanical-dorsal plating was compared with cerclage wiring and modified tension band cable fixation in a comminuted patella fracture model in 36 cadaveric patellae. Constructs were tested at 0° and 45 degrees of flexion. Clinical-we reviewed a consecutive series of patella fractures in 2 centers for outcome and complications. MAIN OUTCOME MEASUREMENTS: Biomechanical-construct stiffness. Clinical-reduction, union, complications, and range of motion. RESULTS: Stiffness was greatest in dorsal plating at both 0° and 45 degrees. Dorsal plating (976 N, 1643 N) > modified tension band (317 N, 297 N) > cerclage (89.8 N, 150.3 N) at 0 and 45 degrees, respectively. 51 patients with patella fractures had them fixed with dorsal 2.7-mm mini fragment plates including a distal to proximal lag screw through the plate from the nose of the patella. 9 cases were small distal fragments not easily managed with screws and cables. All patients were followed up to union. There were 2 infections (1 superficial and 1 deep with nonunion), and 5 had implant removal (9.8%). CONCLUSIONS: Dorsal plating is biomechanically and clinically superior to modified tension band and cerclage techniques in comminuted patella fractures. This method allows for fixation of small distal pole fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

What is the Real Rate of Radial Nerve Injury After Humeral Nonunion Surgery?

OBJECTIVES: To determine the radial nerve palsy (RNP) rate and predictors of injury after humeral nonunion repair in a large multicenter sample. DESIGN: Consecutive retrospective cohort review. SETTING: Eighteen academic orthopedic trauma centers. PATIENTS/PARTICIPANTS: Three hundred seventy-nine adult patients who underwent humeral shaft nonunion repair. Exclusion criteria were pathologic fracture and complete motor RNP before nonunion surgery. INTERVENTION: Humeral shaft nonunion repair and assessment of postoperative radial nerve function. MAIN OUTCOME: Measurements: Demographics, nonunion characteristics, preoperative and postoperative radial nerve function and recovery. RESULTS: Twenty-six (6.9%) of 379 patients (151 M, 228 F, ages 18-93 years) had worse radial nerve function after nonunion repair. This did not differ by surgical approach. Only location in the middle third of the humerus correlated with RNP (P = 0.02). A total of 15.8% of patients with iatrogenic nerve injury followed for a minimum of 12 months did not resolve. For those who recovered, resolution averaged 5.4 months. On average, partial/complete palsies resolved at 2.6 and 6.5 months, respectively. Sixty-one percent (20/33) of patients who presented with nerve injury before their nonunion surgery resolved. CONCLUSION: In a large series of patients treated operatively for humeral shaft nonunion, the RNP rate was 6.9%. Among patients with postoperative iatrogenic RNP, the rate of persistent RNP was 15.8%. This finding is more generalizable than previous reports. Midshaft fractures were associated with palsy, while surgical approach was not. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.