Six patients with nonunion of osteoporotic humeral shafts were treated prospectively at two tertiary referral centres from 2005 to 2007 using an intramedullary fibular strut graft and dynamic compression plate (DCP). Indication for osteosynthesis using the fibular strut and DCP in this study was a diaphyseal fracture of the humerus which had remained ununited for at least four months and was associated with severe osteoporosis and pencil-thin cortices. Patients with an excessively scarred, indurated soft-tissue envelope or with a poor blood supply were excluded and treated by a vascularised fibular transfer and hence excluded from the study. Because of the rarity and complexity of this specific problem it was not possible to include a control group.
Average age of the patients was 65.33 years (range, 54–84). There were four females and two males (Table ). Five patients had involvement of left humerus and only one on the right side. Three patients each had fractures of mid-shaft and junction of middle and proximal thirds. Five were closed fractures and one open fracture had eventual atrophic nonunion upon presentation. All patients had mild pain, tenderness and gross abnormal mobility at the nonunion site, and limitation of activities of daily living. All patients had stiffness of shoulder and elbow to varying degrees. Average delay at presentation from the time of injury was 13.33 months (range, 7–26 months). Preoperative DASH score averaged 84±5 (range, 77–97). Two patients each had diabetes mellitus and ischemic heart disease and three had hypertension. None of the patients were smokers. Five patients with closed fractures had nonunion following conservative treatment.
Patients with osteoporotic humerus nonunion included in the study
All patients underwent surgery under general anaesthesia after administration of prophylactic antibiotics. Mid-shaft fractures and fractures at the junction of middle and lower thirds were exposed through a posterior approach with care taken to identify and protect the radial nerves. Fractures at the junction of proximal and middle thirds were treated through an anterolateral approach. Fracture fragments were freshened off the devitalised bone and fibrous tissue up to the point of bleeding bone ends, and the medullary canal was opened using a drill. Both fragments were then reamed progressively using serial hand reamers up to the point of reaching the fairly healthy cortical bone.
The mid-shaft of fibula was then harvested under tourniquet control with care taken to identify and protect the superficial peroneal nerve. Fibular shaft of excess length was harvested so that it could be trimmed as necessary. Three sides of the fibula were trimmed so as to enable it to snugly telescope into the fracture fragments across the fracture site. If the thickness did not permit its use, it was conversely bevelled at two ends leaving behind the full thickness shaft in the middle which later would bridge the nonunion site or bone defect more effectively. The strut was pushed into one of the fracture fragments and the exact length of graft that needed trimming was assessed. Once the final shaping of the graft was done, the fracture was reduced with the intramedullary fibular graft spanning the fracture site.
Osteosynthesis across the fracture site was achieved using a dynamic compression plate and screws in compression mode. An additional Muller’s compression device was used at one end of the plate to achieve intraoperative compression at the fracture site in all patients. At least three screws on each side of the fracture with three or four cortical purchase for each of the screws were attempted. The remaining excess pieces of fibular graft were packed longitudinally bridging the fracture site. None of the patients had iliac crest bone grafting. Patients with elbow and shoulder stiffness underwent passive joint manipulation at the end of surgery. All patients were protected in an arm sling for a period of three weeks after the surgery. Elbow and shoulder mobilisation was initiated aggressively after three weeks. Lifting of weights using the operated limb was deferred for a period of three months or until osseointegration of the fibular ends or fracture healing.
At final follow-up, the patients were examined by an independent observer clinically and radiologically. Symptoms of pain, instability, or dysfunction were recorded, and the movement of adjacent joints was measured. Intra- and postoperative complications were documented. Radiographs of the humerus in two orthogonal planes were examined for the presence of bridging bony trabeculae, indicating union, as well as for evidence of loosening or breakage of the implants. Fractures were considered united if at least three of the cortices on radiographs showed evidence of bony trabeculae crossing the fracture site.