Internal fixation with headless compression screws and back buttress plate for treatment of old Hoffa fracture

To analyze the early clinical and radiographic outcomes of Hoffa fractures treated by a standard protocol of open reduction and internal fixation using headless compression screws combined with back buttress plate in a consecutive series of 8 Chinese patients.

Open reduction and internal fixation was performed on all patients. The fractures were anatomically reduced and held temporarily by K-wire. If the ends of fractures were atrophic, autologous bone graft from the ipsilateral iliac crest was packed between the ends. Then the fracture fragments were fixed with AO 6.5 mm headless compression cannulated screws. At least two screws were used to provide rotational stability. One pre-contoured reconstruction plate was placed on the nonarticular surface posteromedially or posterolaterally as back buttress plate.

All the patients were followed up for at least 12 months (range 12-25 months). All fractures achieved anatomical reduction and healed clinically and radiographically. At recent follow-up, the mean flexion degree was 120.6° (range 110°-135°) and the mean extension degree was 2.5° (range 0°-5°). The average visual analogue scale score was 1.6 points (range 0-3). Six patients were assessed as excellent and 2 as good according to the hospital for special surgery knee score system. There were no superficial or deep infections, or hardware breakages. No patient had giving way or locking of the knee, though some had intermittent pain and swelling after strenuous exercise. Injury mechanism had significant influence on the functional outcome (P=0.046).

Headless compression screws combined with back buttress plate and/or autologous bone grafting to treat old Hoffa fracture is one of effective measures. It would be conducive to not only fracture healing but also early exercise and functional recovery.