Table 1. Summary of the design, sample set and outcome of previous experimental prophylactic augmentation studies aiming at strengthening the osteoporotic proximal femur, grouped according to the used materials.
| Study | Samples | Loading |
Augmentation |
Control group |
Strengthening |
||||
|---|---|---|---|---|---|---|---|---|---|
| N pairs | Mode and velocity (mm s−1) | Type (manufacturer) | Cement amount/implant size, mean±s.d. [range] | Location within the proximal femur | Fracture force (N), mean±s.d. [range] | Fracture energy (J), mean±s.d. [range] | Change in fracture load (%), mean±s.d. (DoM) [range] | Change in fracture energy (%), mean±s.d. (DoM) [range] | |
| First-generation femoroplasty studies | |||||||||
| Heini et al.34 | 10 | Stance (0.033) | PMMA (Palacos, Essex Chemie) | 34 ml [28 to 40 ml] | Neck and intertrochanter | 5764±1394 | 35 | 20±10 (21)* [8 to 40] | 42±32 (48)* [11 to 120] |
| 10 | Fall (2) | 38 ml [28 to 40 ml] | 2499±695 | 17 | 87±47 (82)* [24 to 178] | 249±152 (188)* [50 to 576] | |||
| de Bakker35 | 3 | Fall (100) | PMMA (Antibiotic Simplex, Howmedica International) | 50 ml | Neck and intertrochanter | 5257±2176 | 17±11 | 32±12 (24) [10 to 64] | 109±79 (84) [28 to 185] |
| Beckmann et al.36 | 9 | Fall (2) | Composite (Cortoss, Orthovita) | 40 ml | Neck and intertrochanter | 4430±1550 | 30±11 | 40±22 (43)* [11 to 86] | 211±167 (187)* [52 to 578] |
| Sutter et al.37 | 10 | Fall (100) | PMMA (Spineplex, Stryker) | [40 to 50 ml] | Head, neck, trochanter and subtrochanter | 2870±484 | 16±8 | (37)* | (154)* |
| Second-generation femoroplasty studies | |||||||||
| Zwicky38 | 6 | Fall (100) | PMMA (Vertecem, Synthes) | [9 to 10 ml] | Superior neck cortex (Figure 1a) | 2200±360 | 16.9±4.3 | (23)* | (−27)* |
| Sutter et al.40 | 9 | Fall (100) | PMMA (Spineplex, Stryker) | 15.2±1.5 ml | Neck | 1762 [1530 to 1994] | 10.2 [6.0 to 14.3] | (12) | (14) |
| 9 | 15.1±1.6 ml | Trochanter | 1912 [1470 to 2353] | 5.2 [3.6 to 6.8] | (3) | (129) | |||
| Beckmann et al.41 | 9 | Fall (2) | PMMA (Palamed, Heraeus Medical) | 12 ml [9 to 18 ml] | Single central | 3096±327 | 20.4±4.6 | (23)* | (160)* |
| 6 | Single centrodorsal | 2738±466 | 17.9±5.6 | (35)* | (164)* | ||||
| 6 | Double ventrodorsal | 2743±432 | 29.2±3.1 | (12)* | (−15) | ||||
| 7 | Double craniocaudal | 3696±601 | 44.2±10.4 | (−26)* | (−20) | ||||
| Fliri et al.42 | 5 | Fall (free fall) | PMMA (Vertecem, Synthes) | 11 ml [8 to 14 ml] | Sup and inf neck cortices, V-shaped | 3370±937 [2499 to 4726] | 10.0±5.8 [4.8 to 18.0] | −9±24 (−11) [−41 to 23] | 124±198 (102)* [17 to 477] |
| Springorum et al.43 | 10 | Fall (2) | PMMA (Palamed, Heraeus Medical) | [8 to 15 ml] | Single dorsal and caudal | 2763±1336 [879 to 5113] | 21.4±16.0 [5.1 to 55.0] | 45±33 (34)* [3 to 90] | 214±203 (118)* [1 to 636] |
| Basafa et al.44 | 8 | Fall (100) | PMMA (Spineplex, Stryker) | 9.5±1.7 ml | Subject-specific | 2576±1273 [1360 to 5410] | 9.2±5.2 [2.9 to 16.8] | 40±29 (30)* [−17 to 74] | 103±28 (94)* [47 to 139] |
| Raas et al.48 | 6 | Stance (2) | Traumacem (Synthes) | 13 ml [11 to 15 ml] | Sup and inf neck cortices, V-shaped | 6619 median [5278 to 10512] | 24 median [18 to 31] | (10 median) | (−1 median) |
| Other non-metallic materials and combinations | |||||||||
| de Bakker35 | 1 | Fall (100) | Carbon sleeve and PMMA (Antibiotic Simplex) | 12.7 mm diameter sleeve, 6 ml cement | Oblique in neck, greater trochanter | 2308 | 5.17 | −8 | 14 |
| 4 | Neck contouring composite | 19 mm diameter carbon sleevel, [9 to 15 ml] cement | Neck axis | 4120±2253 [1654 to 6996] | 12.7±7.6 [5.1 to 23.3] | 21±15 (18)* [8 to 42] | 71±44 (71)* [17 to 117] | ||
| Steenhoven et al.54 | 10 | Fall (2) | Silicon rubber (Polydimethylsiloxane, via Zym BV) | 35 ml [28 to 42 ml] | Head, neck and intertrochanter | 3097±1030 [1407 to 4710] | NA | −4±37 (−10) [−30 to 92] | NA |
| Szpalski et al.53 | 3 fresh 3 fixed | Fall (100) | Y-Strut: PEEK cylinders and PMMA (Cortoss, Stryker) | Two interconnected cylinders filled with 8 ml cement | Neck axis, intertrochanter and shaft | 3627±507 [3056 to 4515] | 19.3±5.5 [13 to 26] | 19±10 (18)* [7 to 34] | 38±38 (31)* [−19 to 81] |
| Hananouchi et al.57 | 7 plastic bones | Fall (100) | Bioactive screw (hydroxyapatite-containing) | Two screws | Neck axis | 2391±270 [1990 to 2704] | NA | (12)* | NA |
| Metal implants | |||||||||
| de Bakker35 | 1 | Fall (100) | Trochanteric gamma nail (Stryker) | NA | Blade: inferior neck cortex, nail: shaft axis | 5113 | 16.9 | 1 | 163 |
| Zwicky38 | 6 | Fall (100) | Dynamic hip screw (Synthes) | 7.3 mm diameter, 95 mm length, 3 ml cement augmentation | Inferior neck cortex (Figure 1b) | 3340±1490 | 22.6±14.1 | (−8) | (−6) |
| Springorum et al.43 | 10 | Fall (2) | Steel spiral (custom) | NA | Neck axis | 2459±1099 [1066 to 4395] | 35.0±20.7 [10.0 to 80.0] | 47±65 (32)* [13 to 224] | 94±131 (57)* [8 to 457] |
| Widmer et al (unpublished study) | 5 | Fall (free) | V-shape implant system (custom) | Two 5 mm diameter cannulated screws, lateral plate, 1 ml Traumacem V+ (Synthes) per screw | Sup and inf neck cortices, V-shaped (Figure 1d) | 2693±1080 | 5.0±2.0 | 27±29 (21) [−6 to 57] | 38±39 (30)* [−3 to 85] |
| Raas et al.48 | 6 | Stance (2) | PFNA blade (Synthes) | NA | Neck axis | 6958 median [5170 to 10224] | 31 median [21 to 42] | (−7 median)* | (−10 median) |
Abbreviation: NA, not available.
Strengthening is expressed with respect to the properties of the contralateral non-augmented bone. The mean and s.d. were computed by averaging the pair-wise strengthening of all samples, whereas difference of the means (DoM) was computed from the mean properties of the control and augmented groups within the given study. Stars (*) indicate significant differences compared with control (P<0.05). The median value is shown if the mean was not provided.