Internally fixed femoral neck fractures. Early prediction of failure in 203 elderly patients with displaced fractures.

After internal fixation of a femoral neck fracture, 3 months is the critical time for planning rehabilitation of the patient. Most failures in the elderly occur within this time. In a series of 165 patients, we followed 127 women and 38 men with a median age of 81 (63-97) years from an examination at 3 months to reoperation or survival of the hip. 36 patients had radiographic signs of disturbed healing at the 3-month follow-up--change in fracture position by 10 mm, change in screw position by 5%, backing of the screws by 20 mm, or perforation of the femoral head by the screw. These signs had a high association with local complications and need for a later reoperation. High age and male sex increased this association. Signs of impaired healing made nonunion likely, but did not predict late segmental collapse of the femoral head. Patients with signs of disturbed healing and those closest to them should be informed about the value of early check-ups in case of pain and impaired function.

Biases in a randomized comparison of three types of screw fixation in displaced femoral neck fractures.

We studied fixation of displaced femoral neck fractures prospectively in a randomized multicenter study, comparing 2 Olmed screws, 2 Tronzo screws and 3 Ullevaal hip screws. The study population consisted of 482 women and 125 men, of whom 432 women and 100 men were older than 65 years of age. Their median age was 80 (54-97) years. Despite agreement on criteria, the rates of reoperations for pain and failure--salvage (prosthesis replacement) and other reoperations (removal of implant)--differed significantly between the 3 hospitals regardless of type of fixation. In total, the percentages of salvage operations were: Olmed screw 17/175, Tronzo 17/130 and Ullevaal screw 11/302 (n.s.); the percentages of other reoperations were 11, 6 and 13, respectively (n.s.). In the whole series, the 2-year rate of salvage operations was 14%. No differences between the implants were found in patients older than 65 years of age. We conclude that an agreed, common definition of a hard end-point (reoperation) does not ensure comparability of results, because of differences in clinical decision making.

Fixation of displaced femoral neck fractures with a sliding screw plate and a cancellous screw or two Olmed screws. A prospective, randomized study of 225 elderly patients with a 3-year follow-up.

BACKGROUND AND AIMS: To analyse the importance of fixation method in displaced femoral neck fractures and to identify factors predictive of failure of the fixation. MATERIAL AND METHODS: Two hundred and twenty-five patients were included in a prospective, randomised study and operated on for a displaced, subcapital fracture of the femoral neck with either a sliding screw plate and a parallel cancellous screw (SSP), or two Olmed screws. The median follow-up time was 39 (22-51) months, excluding reoperated and dead patients. RESULTS AND CONCLUSIONS: Operation and anaesthesia time was considerably longer for the SSP system. The risk of failure was significantly increased (odds ratio 6.6) for patients operated with SSP outside ordinary working time. Poor reduction was recognized as a risk factor of failure for both types of fixation (odds ratio 3.1). The rate of reoperation within 3 months was 18.5% in the SSP group and 9.4% in the Olmed screw group. The rates of nonunion were 6.2% and 8.5%, respectively. The rates of late segmental collapse, 18.0% and 19.5% of all united fractures, respectively, decreased with increasing age (odds ratio 0.88). Salvage operations (replacement with bipolar or total hip prosthesis) were made in 30.6% and 26.5% of the cases, and the total rates of reoperation were 37.0% and 29.1%, respectively. We conclude that both treatment methods result in an unacceptably high rate of failures and reoperations, and that alternative treatment, prosthesis replacement, should be considered in selected cases.

Primary and secondary Charnley-Hastings hemiarthroplasty in displaced femoral neck fractures and their sequelae.

298 women and 36 men, median age 80 (range 40-95) years with 340 femoral neck fractures were treated with Charnley-Hastings hemiarthroplasty and followed for 41 (range 12-86) months. 107 replacements were primary because of poor reduction and 233 were secondary, performed during 60 months after the injury because of disturbed fracture healing. The results of primary and secondary replacements regarding morbidity, mortality, prosthesis failure and survival were similar. The major postoperative complications were: early wound infection (10 cases, 2.9%), dislocation of the prosthesis (16 cases, 4.7%), fracture of femoral shaft (nine cases, 2.7%), and loosening of components with reoperation (six cases, 1.8%). In total 33 reoperations (9.7%) were performed. When failure of the prosthesis was defined as dislocation, fracture or removal of part or whole prosthesis, the three-year and six-year survival rates were 89 and 80%, respectively. Defining the failure as removal of prosthesis component(s) only, the success rates were 96 and 94%, respectively. We conclude that cemented bipolar prosthesis offers a good alternative for salvage of displaced or failed femoral neck fracture.

Implant/bone constructs in femoral neck osteotomy. An autopsy study.

Previous studies have suggested that three rather than two screws may give better results in the treatment of femoral neck fractures. In the present study, the strength of various screw/bone constructs in femoral neck osteotomy was analyzed. Transverse osteotomies on 65 cadaver femora were fixed with two or three screws of two types: one with a shank diameter of 6 mm and thread diameter of 8 mm, and a prototype screw with equal shank and thread diameter of 7 mm. The femoral heads were subjected to static and cyclic loads in the one-legged stance position. Single-energy quantitative computed tomography measurements were correlated to load. The two experimental models resulted in different patterns of failure of the bone/implant constructs, otherwise the results were similar. Three of the prototype screws gave the strongest construct, while two of the other screw type were stronger than three. The explanations for the diverging properties of the different bone/implant constructs may be that large threads destroy too much of the bone trabeculae, and that screw threads larger than the shank may destroy the drill canal and produce an unstable situation compared with screws with equal shank and thread diameter.

Prediction of fixation failure in femoral neck fractures. Comminution and avascularity studied in 40 patients.

We performed 99m-Tc diphosphonate scintimetries in 40-elderly patients who had undergone screw fixation for a recent subcapital femoral fracture and analyzed their preoperative radiographs. The data were subjected to a logistic regression analysis. Both comminution of the calcar femorale and reduced scintimetric uptake were predictive for failure of the osteosynthesis during the first year. Fracture comminution was more predictive for early failures during 3 months and scintimetry for the later failures.

Nonunion of tibial shaft fractures treated with locked intramedullary nailing without bone grafting.

Twenty-five nonunions of tibial fractures were treated with Grosse-Kempf slotted, locked nails in 20 men and 5 women 6 to 54 months after fracture. No bone grafts were performed in connection with nailing. For better alignment, opening of the nonunion site, fibular osteotomy/resection, or both were used. In one patient reoperation with nailing and bone grafting was necessary after the first nail broke. There were three postoperative infections (12%), two with persistent drainage. All nonunions healed. In one patient an external rotatory malalignment was corrected by a later osteotomy. In no case was the function of the ankle or foot impaired by the index operation. Static locking was not unfavorable for healing. We conclude that bone grafting is rarely needed and function is restored early after locked nailing of tibial nonunions.

Prediction of disturbed healing in femoral neck fracture. Radiographic analysis of 149 cases.

To determine factors predictive of early healing disturbances after fixation of femoral neck fracture, the radiographic and clinical data of 149 patients were subjected to a logistic regression analysis comparing them with the results 3 months postoperatively. As in previous studies, fracture reduction distinguished between fractures with or without healing disturbances. The following signs in the preoperative radiographs were predictive of unfavorable outcome: small head fragment, comminution of the calcar femorale, and varus angulation of the head. Fractures with negative predictive signs may be selected for primary arthroplasty.

Comparison of functional bracing and locked intramedullary nailing in the treatment of displaced tibial shaft fractures.

Thirty-five displaced tibial shaft fractures, treated with functional bracing were compared with 43 similar fractures, treated with locked intramedullary nailing. There were 22 excellent/good results in the brace group and 38 in the nail group. There was one infection in the brace group and three in the nailed group. There were five delayed unions and two nonunions in the brace group and one delayed union in the nail group. The functional results in the nailed group were better than the braced group but locked intramedullary nailing of tibial shaft fractures require special resources and training. Locked intramedullary nailing fullfils all the functional criteria for acceptable fracture care.

Implant holding power of the femoral head. A cadaver study of fracture screws.

The holding power against axial pull-out forces of eight different screws implanted in the femoral heads of cadavers was tested. The Olmed screw had the greatest resistance to pull-out forces followed by the recently designed Ullevaal screw with long threads, and the von Bahr screw. There were substantial differences in the holding power in the four sectors of the femoral head. The holding power was strongly correlated with the logarithm of the moment of inertia of the screw threads, which is a function of the area and number of the threads (r = 0.94, P = 0.0002).

Radiographic prediction of early failure in femoral neck fracture.

We studied the primary radiographs of 56 patients treated with osteosynthesis for a displaced femoral neck fracture. The radiographic findings were subjected to a multiple regression analysis together with the results 3 months postoperatively. A primary fracture displacement of more than 20 mm on the AP film and a defect of the calcar due to fracture comminution were associated with a failed osteosynthesis.