Fracture classification
According to the classification of Rommens & Hofmann, FFP type II with unilateral and/or bilateral fractures (type II a, type II b and type II c) was found in 250 of 292 (85.7 %), FFP type III c in 14 of 292 (4.8 %) and FFP type IV (type IV b and type IV c) in 28 of 292 (9.5 %) of the patients treated (Fig. 1).
Of the 292 patients treated, 91 (31.2%) had unilateral and 201 (68.8%) had bilateral FFS, totalling 493 FFS.
As an indication of the different ages of the FFS, the bilateral fractures usually showed varying degrees of oedema and in some cases laterally differentiated sclerosis in the area of the fracture zones on CT and MRI imaging (Fig. 2).
With a distribution of 208 out of 493 of the FFS, 42.4% were found to have a Denis type 1, 21 out of 493 or 4.2% had a Denis type 2, 0 out of 493 or 0% had a Denis type 3, 214 out of 493 or 43.3% had a Denis type 1 – 2, and 50 out of 493 or 10.1% had a Denis type 1 - 2 - 3 fracture zone (Fig. 3).
Pain and mobility development
Consecutively, 50 patients with a pain level ≤ 5 (Group 1) and 100 patients with a pain level > 5 (Group 2) were included. Patients with a pain level of ≤ 5 benefited from the conservative therapy measures, whereby pain levels > 5 significantly delayed the development of mobility (Fig. 4 a and Fig. 4 b).
Over the course of the study, 36 out of 150 (24%) patients were referred for interventional (10 out of 36) and osteosynthetic therapy (26 out of 36), due to increasing fracture extension, pain > 7 and pronounced immobility.
After sacroplasty, pain was reduced rapidly and significantly (p < 0.001), which quickly allowed a marked improvement in mobility, with no significant difference found between vertebro- (VSP), balloon (BSP), radiofrequency (RFS) and cement (CSP) sacroplasty (Fig. 5 a and Fig. 5 b).
A total of 119 patients underwent cement augmentation. Cement leakage was found in 4 out of 20 patients (20 %) after VSP (Group 3) and in 6 out of 49 patients (12.2 %) after CSP (Group 4). None of the leaks were symptomatic. For BSP (Group 5) and RFS (Group 6) with 25 patients each, leakage was ruled out.
The planned osteosyntheses of 59 patients with the following fracture morphology:
FFP type II = Group 7: 2 FFP type II a, 3 FFP type II b and 4 FFP type II c;
FFP type III = Group 8: 19 FFP type III c and
FFP type IV = Group 9: 26 FFP type IV b and 5 FFP type IV c
were carried out as planned.
Iliosacral screw fixation was performed 38 times (with additional cement augmentation in 32 of 38), transsacral screw fixation 8 times, a transsacral positioning rod 3 times, percutaneous plate osteosynthesis once, lumbopelvic stabilisation 8, and an internal fixator with additional transiliac screw fixation once.
In terms of pain reduction and mobilisation capacity, patients benefited from osteosynthesis, although more complex fracture types with lumbopelvic stabilisation performed required a longer period of recovery (Fig. 6 a and Fig. 6 b).
Material loosening occurred in 8 of 59 patients, but this did not require revision.
There were no deaths during the hospital stay.
In the assessment of self-reliance, patients achieved an average of 76 score points after conservative therapy, 83 score points after sacroplasty and 84 score points after osteosynthesis at the end of 24 months.
However, of the 292 patients treated, only 81 patients (27.7%) achieved the same physical fitness as before the fracture event.
Mortality
The mortality rate after 12 months was 21.7% for the conservative, 8.4% for the interventional and 13.6% for the surgical therapy group; the differences are significant. In patients in the conservative therapy group who were difficult to mobilise due to pain, the mortality rate increased to 24.3% (Tab. 2).
Tab.: 2
Mortality in comparison of the therapy options.
Therapy
(Group)
|
12-month mortality (%)
|
Conservative
(1 and 2)
|
21.7
(18.4 and 24.3)
|
Interventional
(3; 4; 5 and 6)
|
8.4
(9.1; 8.0; 8.1 and 8.2)
|
Osteosynthetic
(7; 8 and 9)
|
13.6
(11.1; 10.5 and 16.1)
|
Over a period of 12 months after the start of therapy, the deceased could be clearly recorded.
The average percentages differed significantly between Groups 1 and 2 at p < 0.05. No significant difference was found between Groups 3 to 6 and Groups 7 to 9 at p > 0.83.
The conservatively treated patients showed a significant difference compared to the interventionally treated patients at p < 0.001 and compared to the osteosynthetic treated patients at p < 0.05, with an effect size of 0.87 and 0.74, respectively.
Legend:
Group 1: Conservative therapy at a pain level ≤ 5
Group 2: Conservative therapy at a pain level > 5
Group 3: Cement augmentation by VSP
Group 4: Cement augmentation by BSP
Group 5: Cement augmentation by RFS
Group 6: Cement augmentation by CSP
Group 7: Osteosynthesis of FFP type II
Group 8: Osteosynthesis of FFP type III
Group 9: Osteosynthesis of FFP type IV
Patient satisfaction
Subjective satisfaction with the therapies was best after sacroplasty at 12 and 24 months, followed by osteosynthesis and conservative measures (Tab. 3).
Tab.: 3
Patient satisfaction, for which the pain development from Fig. 4a, Fig. 5a and Fig. 6a as well as the mobility development from Fig. 4b, Fig. 5b and Fig. 6b were taken into account. Post-therapeutic, persistent pain > 5, as in Groups 2 and 9, blocks rapid mobilisation and leads to moderate to poor satisfaction.
Group
|
Pain reduction
|
Development of mobility and self-reliance
|
Subjective satisfaction
|
1
|
slow, acceptable
|
moderate
|
moderate
|
2
|
slow, inacceptable
|
moderate to poor
|
poor
|
3
|
rapid, good
|
marked
|
good
|
4
|
rapid, good
|
marked
|
good
|
5
|
rapid, good
|
marked
|
good
|
6
|
rapid, good
|
marked
|
good
|
7
|
rapid, good
|
marked
|
good
|
8
|
rapid, good
|
marked
|
good
|
9
|
delayed, acceptable
|
moderate
|
moderate
|
Legend:
Group 1: Conservative therapy at a pain level ≤ 5
Group 2: Conservative therapy at a pain level > 5
Group 3: Cement augmentation by VSP
Group 4: Cement augmentation by BSP
Group 5: Cement augmentation by RFS
Group 6: Cement augmentation by CSP
Group 7: Osteosynthesis of FFP type II
Group 8: Osteosynthesis of FFP type III
Group 9: Osteosynthesis of FFP type IV
Vitamin D and BMD
All patients had a pronounced vitamin D deficiency and manifest osteoporosis.
Vitamin D
The vitamin D level was significantly (p < 0.001) lower than 30 nmol/l ≙ 12 ng/ml in all patients. Vitamin D levels were 8 - 28 (Ø 14.1) nmol/l ≙ 3.2 - 11.2 (Ø 5.6) ng/ml in unilateral fractures and 0 - 18 (Ø 7.2) nmol/l ≙ 0 - 7.2 (Ø 2.9) ng/ml in bilateral, more complex fractures (Fig. 7), the difference in mean vitamin D levels being significant (p < 0.05).
BMD
The BMD was 12-74 (Ø 44.3) mg/ml in the patients with a unilateral fracture and 2 - 54 (Ø 31.3) mg/ml in the patients with a bilateral fracture (Fig. 7), the difference in mean BMC values being significant (p < 0.05).
Disease profile
In 128 of 292 (43.8 %) patients in total, at least one previous sintering fracture was found in the thoracic and lumbar spine. Other osteoporosis-associated fractures such as distal radius, proximal humerus, femoral neck, rib and sternal fractures were found in 142 of the 292 (48.6 %) patients. Hypocalcaemia was found in 35 % and secondary hyperparathyroidism in 48 % of all patients. Additional lung disease was found in 23.6%, cardiovascular disease in 45.2%, hypertension in 77.1%, renal insufficiency in 34.2%, diabetes mellitus type II in 72.8%, PAOD in 70.3% and obesity in 60.2% of all patients. A varying degree of nicotine consumption was reported by 48.3 % of all patients.