Aims: Our purpose was to determine if DHS fixed with hydroxyapatite (HA)-coated AO/ASIF screws improves fixation and clinical outcomes in osteoporotic trochanteric fracture patients. Methods: 120 osteoporotic patients with trochanteric fractures were randomized to receive 135° 4-hole DHS fixed with either standard lag and cortical stainless-steel AO/ASIF screws (Group A) or HA-coated lag and cortical stainless-steel AO/ASIF screws (Group B). Inclusion criteria were: female; age ≥65 years; AO type A1 or A2; and BMD lower than -2.5 T score. Results: Tip Apex Distance (TAD) was 22±4mm in Group A and 23±5mm in Group B (ns). In Group A there were 4 cut-out cases and none in Group B (p< 0.05, β=0.8). Post-op (ns) and 6 month (p=0.008) femoral neck-shaft angle was 134±5° and 129±7° (Group A) and 134±7° and 133±7° (Group B). At 6 months, Harris Hip Score was 63±22 (Group A) and 71±18 (Group B) (p=0.02). Conclusions: HA-coated AO/ASIF screws prevent fracture varization and lag screw cutout, thus improving clinical outcomes in osteoporotic trochanteric fracture patients.

Aims: We compared treatment with external fixation (EF) vs DHS in osteoporotic trochanteric fractures. Methods: 40 patients were randomized to receive either 135° 4-hole DHS (Group A) or an Orthofix trochanteric external fixator with 4 hydroxyapatite-coated Osteotite pins (Group B). Inclusion criteria were: female, age ≥65 years, AO fracture type A1-2 and BMD lower than -2.5T score. Fixators were removed at 3 months. Results: There were no differences in patient age, fracture type, BMD, ASA, hospital stay, or quality of reduction. Operative time was 64±6 minutes in Group A and 34±5 minutes in Group B (p< 0.005). Average number of blood transfusions was 2±0.1 in Group A, and none in Group B (p< 0.0001). Fracture varization at 6 months was 6±8° in Group A and 2±1° in Group B (p=0.002). Harris Hip Score was 62±20 in Group A and 63±17 in Group B (ns). In Group B, no pin-track infections occurred. Pin fixation was maintained over time, as shown by no differences between pin extraction and insertion torque. Conclusions: We consider EF a viable treatment option for this patient population. Operative time is short, postoperative complications are minimized, and fixation is improved.

We compared thirty-eight patients from three orthopaedic centres who had external fixation of the femur or the tibia. Patients were randomised to receive standard (tapered 5/6 millimeter) pins (Group A) or OsteoTite (hydroxyapatite coated tapered 5/6 mm) pins (Group B).

In Group A there were 18 patients who received 71 pins. Average age of the patients was 49±12 years. Three patients had external fixation in the femur and 15 in the tibia. External fixation was used in three types of treatment: fracture fixation (4), knee osteotomy (12), and bone-transport (2). Two different fixator frames were used: a unilateral fixator was mounted in 15 patients and a circular fixator in three patients. In Group B, 20 patients (average age: ± 48 years) received 86 pins. Four patients had external fixation in the femur and 16 in the tibia. External fixation was used in three types of treatments: fracture fixation in three patients, knee osteotomy in 13 patients, and bone-transport in four patients. Two different fixator frames were used: a unilateral fixator was mounted in 16 patients and a circular fixator in four patients.

No significant difference regarding sex, age, external fixation treatment type, external fixation frame, and length of treatment were observed between the two groups. Mean final pin insertion torque was 477 ± 214 Newton cm in Group A and 339 ± 184 in Group B (p< 0.01). Mean pin extraction torque was 205 ± 169 Newton cm in Group A and 532 ± 211 in Group B (p< 0.01). Pin extraction torque was significantly lower compared to the corresponding insertion torque in Group A (p< 0.01). Pin extraction torque was significantly higher compared to the corresponding insertion torque in Group B (p< 0.01). Pin tract infection rate was lower in Group B compared to Group A (p< 0.01).

This study shows that hydroxyapatite coating was clinically effective in the improvement of the bone pin interface strength of tapered pins. By using these pins, deterioration of the bone pin interface strength can be avoided and external fixation complications minimised.

We measured the insertion and extraction torque forces in a randomised study of 76 external fixation screws in 19 patients treated by hemicallotasis for osteoarthritis of the medial side of the knee. The patients were randomised to have either standard tapered screws (Orthofix 6/5 mm) or the same screws with hydroxyapatite (HA) coating. One patient had two standard and two HA-coated screws. All patients had an anterior external fixator (Orthofix T-garche), with two screws in the proximal tibial metaphysis parallel to and about 2 cm below the joint surface and two in the tibial diaphysis.

The mean torque forces for insertion of the standard screws were 260 Ncm for the proximal to medial screw, 208 for the proximal to lateral screw and 498 and 546 Ncm for the diaphyseal pins. The corresponding forces for the HA-coated pins were not significantly different. The torque forces for the extraction of the standard pins were 2 Ncm for the proximal pins, 277 and 249 Ncm for the distal pins and 482, 478, 585 and 620 Ncm, respectively (p < 0.005) for the HA-coated pins.

All 18 of the metaphyseal standard screws were loose at extraction (extraction force < 20 Ncm), but only one of the HA screws in the metaphysis was loose. In the diaphysis the standard screws lost about 40% of their fixation in contrast to the HA-coated screws which retained full fixation strength.