Norian SRS cement compared with conventional fixation in distal radial fractures. A randomized study

A prospective, randomized multicenter study was conducted to evaluate closed reduction and immobilization with and without Norian SRS (Skeletal Repair System) cement in the management of distal radial fractures. Norian SRS is a calcium-phosphate bone cement that is injectable, hardens in situ, and cures by a crystallization reaction to form dahllite, a carbonated apatite equivalent to bone mineral.

A total of 323 patients with a distal radial fracture were randomized to treatment with or without Norian SRS cement. Stratification factors included fracture type (intra-articular or extra-articular), hand dominance, bone density, and the surgeon's preferred conventional treatment (cast or external fixator). The subjects receiving Norian SRS underwent a closed reduction followed by injection of the cement percutaneously or through a limited open approach. Wrist motion, beginning two weeks postoperatively, was encouraged. Control subjects, who had not received a Norian SRS injection, underwent closed reduction and application of a cast or external fixator for six to eight weeks. Supplemental Kirschner wires were used in specific instances in both groups. Patients were followed clinically and radiographically at one, two, four, and between six and eight weeks and at three, six, and twelve months. Patients rated pain and the function of the hand with use of a visual analog scale. Quality of life was assessed with use of the Short Form-36 (SF-36) health status questionnaire. Complications were recorded.

Significant clinical differences were seen at six to eight weeks postoperatively, with better grip strength, wrist range of motion, digital motion, use of the hand, and social and emotional function, and less swelling in the patients treated with Norian SRS than in the control group (p < 0.05). By three months, these differences had normalized except for digital motion, which remained significantly better in the group treated with Norian SRS (p = 0.015). At one year, no clinical differences were detected. Radiographically, the average change in ulnar variance was greater in the patients treated with Norian SRS (+2.0 mm) than in the control group (+1.4 mm) (p < 0.02). No differences were seen in the total number of complications, including loss of reduction. The infection rate, however, was significantly higher (p < 0.001) in the control group (16.7%) than in the group treated with Norian SRS (2.5%) and the infections were always related to external fixator pins or Kirschner wires. Four patients with intra-articular extravasation of cement were identified; no sequelae were observed at twenty-four months. Cement was seen in extraosseous locations in 112 (70%) of the SRS-treated patients; loss of reduction was highest in this subgroup (37%). The extraosseous material had disappeared in eighty-three of the 112 patients by twelve months.

Our results indicate that fixation of a distal radial fracture with Norian SRS cement may allow for accelerated rehabilitation. A limited open approach and supplemental fixation with Kirschner wires are recommended. Additional or alternate fixation is necessary for complex articular fractures.