Session IV - Geriatrics
*The Proximal Femoral Nail (PFN) versus the Medoff Plate in the Treatment of Unstable Trochanteric Fractures
Wilhelmina HG Ekström, MD1; Sune Larsson, PhD2; Björn Ragnarsson, MD2; Karl Akke E Alberts, MD1;
Purpose: Several implant designs have recently been developed to reduce the risk for mechanical complications during treatment of multi-fragmentary intertrochanteric and subtrochanteric fractures. For example, dynamic devices such as the dual sliding-plate implant take advantage of the principle of load-sharing between fracture fragments and the implant. Another implant design often utilized for fixation of such fractures is a short intramedullary nail in order to reduce the considerable bending moment that has to be neutralized by the implant during the course of fracture healing. Treatment of proximal femoral fractures with a dual-dynamic plate screw system or with a short intramedullary nail therefore takes advantage of different biomechanical principles that might be of importance not only for reducing the complication rate but also for improving clinical and functional outcome.
We compared functional outcome, rehabilitation, and complication rates of patients with multi-fragmentary trochanteric and subtrochanteric fractures who underwent fixation with either a short nail (Proximal Femoral Nail [PFN] with dynamization along the femoral neck) or the Medoff screw plate (dynamization along both the femoral neck and shaft).
Methods: In a prospective randomized study at two level I trauma centers, 211 elderly patients with an unstable trochanteric fracture (AO/OTA, A2.1-3) or a subtrochanteric fracture (AO/OTA, A3.1-3) were included. A total of 104 fractures were treated with the PFN and 107 with the Medoff plate. The mean age was 82 years in both groups, and 76% of the patients were female. The procedure was performed by 46 different surgeons. The patients were examined at 6 weeks, 4 months, and 12 months with radiography and assessment of functional performance, abductor muscle strength (CSD 400 dynamometer), living conditions, and pain at walking and at rest (Borg category scale and a visual analog scale score, 0-10, with 0=no pain and 10= worst possible pain).
Results: There was no significant difference between the groups in operating time (median 52 minutes in the PFN group and 59 minutes in the Medoff group). The patients in the PFN group had a smaller amount of perioperative blood loss compared with the Medoff group (median 200 ml and 350 ml, respectively, P <0.05000), but the median number of blood transfusions were two units in each group.
At 6 weeks, 163 patients, at 4 months, 146 patients, and, at 12 months, 120 patients could attend the follow-up examinations. The walking ability at 6 weeks was significantly better with less need for walking aids in the PFN group compared with the Medoff group (P = 0.004); 88% in the PFN group and 72% in the Medoff group were able to walk a 15-meter distance at 6 weeks. At 4 and 12 months, the walking ability continued to improve in both groups with no significant difference between the two groups. The ability to rise from a chair without arm support improved over time with no significant differences between the groups at any of the time points. At 6 weeks, 73% in the PFN group and 79% in the Medoff group were unable to rise from a chair without arm support, and the corresponding numbers at 12 months were 48% and 47%, respectively. There was no difference between the groups in the ability to climb one step, and the ability improved over time for both groups. Assessment of pain at walking showed a decrease from a median value of 3 at 6 weeks, 2 at 4 months, to 0 at 12 months for both groups. No difference was found between the groups. Median pain at rest was 0 for both groups during the study period. A total of 81% of the patients in the PFN group and 74% in the Medoff group were admitted from their own homes. At 12 months, 69% in the PFN group and 77% in the Medoff group had returned to their own homes. There were no differences in living conditions between the groups.
All fractures eventually united, but we had serious mechanical complications. The most serious complication was cut-out of the implant through the femoral head, which was found in five patients treated with the PFN and in two patients treated with the Medoff plate. Nine patients in the PFN group were reoperated on (one early fracture distal to the nail, one repositioning of a locking screw, one hematoma, one loss of position of the femoral neck screw with lateral sliding, and five cut-outs), and one patient in the Medoff group had a repeat operation and another patient in the Medoff group with a cut-out refused to undergo reoperation. Seven patients in the PFN group and six patients in the Medoff group had antibiotic treatment for a superficial infection during their hospital stay. Seven patients in the PFN group and five patients in the Medoff group had sustained one or two additional fractures during the study period.
Discussion: Walking ability was better in patients treated with the PFN in the early postoperative period. In the later rehabilitation period there was no difference in functional performance between patients treated with the two methods. During the first year after the fracture the patient's performance was hindered because of new fractures and other concomitant illnesses, which interfered with their rehabilitation and also with the possibility of living independently. Treatment with the PFN led to more serious complications, some of which necessitated a reoperation. The great number of different surgeons involved might have influenced the complication rate.
Conclusions: Patients fixed with PFN had faster rehabilitation during the first 6 weeks, which is important for this elderly group of patients who also have a high risk for concomitant illnesses. On the other hand, reoperations were more frequent in the PFN group, and it seemed that the PFN was less forgiving of errors related to surgical technique compared with use of the Medoff plate.
* If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options and e-consultant or employee.