We reviewed two groups of data (1 + 2) in different but equally retrospective ways:

1. From the traumatology unit, all cases of transverse process fractures in a 10 year period were collected and followed up.

2. From all hospital departments, all lumbar spine, abdomen and pelvis X-rays in a 20 year period were examined for osseous bridges. In available patient histories and in older X-rays, particular attention was paid to previous traumata and to conditions which could explain activated bone formation or disposition to bleeding.




In the first review, 39 cases of transverse process fractures are found among 28900 trauma admissions in a 10 year period. Only one transverse process fracture is found per 741 Trauma patients, so it is a relatively rare occurrence. In over 70% of the cases, L3 or L4 or both were involved.

Of the 39 cases, 33 are men and 6 are women, with an average age of 31 years. 20 of these patients had at least one follow-up X-ray more than 4 months after the initial examination. Though transverse process fractures appear in conventional X-rays, CT has been used in recent years. CT reveals that some of what could be considered benign lesions are actually complex spine fractures. Therefore CT helps to diminish the risk of overlooking potentially serious injuries of spine, pelvis and thorax and of soft tissues (retroperitoneum, pleurae, lungs).

Only 2 of the fracture cases developed an osseous bridge of transverse processes. Both patients had had violent trauma; one had additional fractures of the pelvis and femur, with peripheral nerve damage.

- 3 patients have tongue-like bone formations not leading to a cross union of transverse processes

- 5 patients have remarkable deformations without an osseous bridge; under those 3 with multiple bone fragments imitating "lumbar ribs" (Fig.1) (the link to the transverse process was not truly pseudarthrotic, because those bony parts were about 0,5 cm or more apart form the transverse processes);

- 2 cases with pseudarthrotic healing of the fractures.

- 10 cases healed with slight deformation of the transverse processes, including one hole-formation in a transverse process,

- 19 vertebral columns healed without deformity.

More than 5% of transverse process fractures developed an osseous bridge.


This incidence may be variable. As more attention is paid to fractured transverse processes, the more mildly damaged (or misdiagnosed) cases will enter the collective. Since the incidence of osseous bridge formation is probably higher after violent trauma than light trauma, the overall incidence will vary with the composition of the collective.



In 14 of the 16 cases, patients had a history of trauma 2-31 years previously which gave evidence of transverse process fractures. X-rays from the time of the accident were only found for 2 of the 16 patients.

The second review, form the entire hospital data, surprisingly reveals 16 osseous bridges of transverse processes, among approximately 52.000 patients in 20 years. This incidence is 0,031%, surprisingly high in comparison to the first review., we find 18 osseous bridges.

Combining search 1 and 2

14 are men, 4 are women, aged form 22 to 77 years .

- 10 patient histories reveal a violent trauma (in the average 12 yrs before), such as a motorbike accident or a fall from a height of more than 12 feet.

- In 7 cases there is direct trauma, though the accidents are less serious.

- One patient had no trauma-anamnesis.

- In no cases is there only indirect trauma such as heavy lifting or stress fracture.

- In no patients were the following conditions found: Diabetes, Psoriasis, pustulous skin lesions, Multiple exostosis, Morbus Bechterew, Hemorrhagic Diathesis.

Own cases:

Nr. age sex trauma y before segments side Pseudarth.
01 (Hi.Wi) 34y m + 2y L1-3 l -
02 (He.Wi.) 62y m + 10y L2-3 l +
03 (Re.Eu.) 47y m + 19y L3-4 l +
04 (Fi.Fr.) 58y m + 8y L3-4 r +
05 (Ef.Jo.) 38y m + 12y L4-ileum l -
06 (Fr.Ge.) 70y m + 30y L2-3 l -
07 (Un.Be.) 47y m + 15y L3-4 l -
08 (Ku.He.) 52y m + 25y L4-S1-ileum l +
09 (We.Ni.) 75y f + 16y L5-ileum l -
10 (Zu.Ma.) 76y f + 20y L5-ileum l -
11 (Sc.Si) 22y f + 2y L2-4 r -
12 (Ko.Er.) 77y m + 20y L3-ileum l +
13 (Ke.Ge.) 42y f - - D12-L1 r -
14 (Pi.Ac.) 46y m + 2y L2-3 r +
15 (Bl.Jo.) 48y m + 5y L3-4 l +
16 (St.Hu.) 44y m + 11y L2-3 l +
17 (Du.Ch.) 32y m + 7y L2-3 l +
18 (We.Dk.) 52y m + 16y L1-2 l -

Segment L2 was present in 6, L3 was in 11 of 18 cases. L4 was present in 7, L5 in 4, S1 in no of 18 cases. No bilateral observation was made. Pseudarthrotics was found in 8 of 18 patients. 16 of the 17 osseous bridges are considered to be traumatic origin. The origin of 1 osseous bridge is unclear.

59 Osseous bridges from the literature were compared with those of our own 18 patients. There is a remarkable conformity of segmental distribution, forms, size between the own observations and the literature.

literature Own patients
Number of patients 59 18
Female 8 4
Male 46 14
no information 5 0
Age (years) at time of observation; between 24-64 22-77
Pseudarthrosis + 43 10
Pseudarthrosis - 16 8
Bridges on both sides 4 0
Bridge on one side 55 18
Left side 31 14
Right side 26 4
More than two segments involved 15 (of 59 cases) 5 (of 18 cases)
Costa 12 2 1
L1 11 2
L2 27 6
L3 50 11
L4 48 7
L5 18 5
Os ileum 5 4