[Unreamed locking intramedullary nailing of humeral fractures--basic evaluation of a patient group].

PURPOSE OF THE STUDY: The aim of the work is to provide an overview of the existing experience in Synthes unreamed humeral nail (UHN).

MATERIAL: Between August 1996 and February 2000 we treated by means of UHN a group of 37 patients (12 men and 25 women), average age 55 years (range, 18-87 years) with a fracture of humeral shaft. According to AO classification in 10 patients it was a case of a fracture of proximal humerus involving the shaft (11B-3) and in 27 cases a fracture of the shaft (12 A, B, C). The whole group was operated on by 11 surgeons.

METHOD: In 26 cases we used the antegrade method and in 11 cases the retrograde one, in dependence on the type and location of the fracture. The assessment was performed in the form of a prospective study. The follow-up including radiograph checks was carried out at the intervals of 6 weeks, 3, 6, 9 and 12 months after the operation or at another 6 weeks or 3 months after the extraction of the nail, if any. In addition we invited the whole group, i.e. 37 patients for the final control examination which all of them attended. This examination was performed by the first author of the work. The average follow-up was 38 months (range, 12-55 months).

RESULTS: The average duration of the surgery in the whole group was 80 minutes, the average duration of x-ray exposure was 3.1 minutes. Peroperative complications occurred in total 42 times in 23 patients. Seven cases required a supplementary incision, i.e. open reduction of the fracture; insufficient nail placement (not into the proper depth) in the humeral head and its prominence into joint line evaluated on the post-operative radiograph) in antegrade nailing occurred 6 times. Problems with locking were encountered 15 times in 10 patients. Comminution of the fragments peroperatively during the insertion of the nail occurred 3 times, peroperative injury of the radial nerve was recorded in total 4 times, always in the antegrade method of the insertion during distal locking from the lateral side. A postoperative complication occurred 16 times in 12 patients, 6 times the radiograph showed penetration of the end of the nail into the shoulder and 6 times the locking screws loosened. No infect was recorded. The mentioned complications required in total 10 revision surgeries in 6 patients (5 of them were treated by the antegrade method). The fracture healed in a good anatomical position in 33 cases. In 4 cases there occurred non-union which was 3 times treated with a plate re-fixation and cancellous bone grafting of which twice successfully. In 2 cases the healing required another revision surgery. A good subjective as well as objective result was achieved almost in 90% of patients. A risk factor from the viewpoint of the limitation of the range of motion in the shoulder proved to be the fracture of 11B3 type and also the antegrade method of nailing, in case of the elbow the retrograde method of nailing. However, the greatest risk was posed by the necessity of a longer post-operative immobilisation of the limb in the case of a not quite stable internal fixation.

DISCUSSION: A relatively high number of complications in our group results from strict criteria we have set. However, also literary data present a relatively high number of variously serious complications. Our results as well as the average duration of the surgery is comparable with other authors.

CONCLUSION: The main indication of UHN are comminuted or multi-level fractures of humerus in the central three fifths of its length. If possible we prefer the retrograde method of nailing, in the antegrade method we recommend distal locking from the anterior aspect of the arm. Transverse or short oblique fractures can be successfully treated by a simpler Hackethal technique. Long spiral fractures are ideally treated conservatively or by plate fixation.