The effects of bone-substitute augmentation on treatment of osteoporotic intertrochanteric fractures

Abstract

Background: Osteoporotic intertrochanteric fractures often have postoperative complications despite a perfect reduction and an optimal fixation. We describe a simple technique using bone substitute augmentation and hypothesize that this method would prevent excessive sliding of the lag screw and potential subsequent complications.

Methods: Between January 2009 and July 2017, patients with osteoporotic intertrochanteric fractures who were treated with a dynamic hip screw (DHS) were enrolled in this retrospective cohort study. DHS group patients received conventional DHS treatment and BSA-DHS group patients received bone-substitute augmented DHS treatment. Factors such as demographics, Parker and Palmer mobility scores, health-related quality of life (HRQoL) scores (short-form Health Survey-12 Physical Component Summary [SF-12-PCS], and SF-12 Mental Component Summary [SF-12-MCS]), morbidities, mortality, and radiographic outcomes were compared.

Results: We enrolled 85 patients: DHS group = 37 and BSA-DHS group = 48. There was significant lag-screw sliding (mean: 9 mm and 3 mm, p < 0.001), varus collapse (mean: 7° and 3°, p < 0.001), and femoral shortening (mean: 10 mm and 3 mm, p < 0.001) in the DHS group compared to the BSA-DHS group. The ability to get around the house was significantly different between the DHS and BSA-DHS groups (p = 0.031) at 3 months. Postoperative scores were not significantly different after 6, 9 or 12 months, however. Scores for the ability to get out of the house and to go shopping and the SF-12-PCS were significantly worse in the DHS group at 3 and 6 months. Malunion and lag-screw cutout were also significantly worse in the DHS group (p = 0.037 and p = 0.033, respectively).

Conclusions: Bone-substitute augmentation appears effective to prevent typical postoperative complications experienced by the DHS group patients, and to improve functional outcomes. Additional prospective randomized large-scale cohort studies are necessary to confirm this conclusion.

Level of evidence: Therapeutic Level III.

Keywords: Bone substitute; Health-related quality of life (HRQoL); Intertrochanteric fracture; Osteoporosis.

Fig. 1

A 3-cc syringe was used to deliver the bone substitutes. The end with a nozzle that connects to a needle was removed with a knife; the end of a hollow barrel with a piston was preserved to carry the bone substitutes.

Fig. 2

Intraoperative fluoroscopy. (A) Adequately reducing fracture fragments, a guide wire was inserted. (B) The lag screw channel was reamed using a DHS reamer. A Kirschner wire (3.0 mm in diameter) was inserted above and parallel to the guide wire and lag screw hole; the guide wire was then removed. The bone substitutes were pushed using the plunger and then gentle hammer taps against the DHS impactor. (C) The guide wire reinserted, and then an assembled lag screw was inserted into the drilled hole.

Fig. 3

Mean hip pain scores. Differences of mean hip pain scores were found between the DHS and BSA-DHS groups at the postoperation periods of 3 and 6 months. (The error bars are for standard deviation).

Fig. 4

The score of the ability to get around the house (indoor walking) was significantly worse in DHS group at postoperation 3 months. (The error bars are for standard deviation).

Fig. 5

For the ability to get out of the house (outdoor walking), significant differences were noted at postoperation 3 and 6 months between the DHS and BSA-DHS groups. (The error bars are for standard deviation).

Fig. 6

Evaluation of the ability to walking during shopping. For patients without bone-substitute augmentation, the mean score of the ability to go shopping was significantly lower than the scores in BSA-DHS group at postoperation 3 and 6 months. (The error bars are for standard deviation).

Fig. 7

The scores of the SF-12 PCS were significantly better in BSA-DHS group at postoperation 3 months and 6 months. (The error bars are for standard deviation).

Fig. 8

SF-12 MCS scores were not significantly different between the groups during the study period. (The error bars are for standard deviation).

Fig. 9

(A) A 84-year-old man with an osteoporotic intertrochanteric fracture (AO/OTA type 31-A2.1). (B) The fracture was fixed with a bone substitute-augmented DHS (BSA-DHS). (C) Lag screw sliding (2 mm) and femoral shortening (2 mm) occurred 2 months postoperatively. (D) Uneventful union of the fracture was noted at 4 months after surgery.