Injury,
53
7, 53-56
External fixation of the pelvic girdle with a trapezoid compression frame P3r Skitis and Erkki 0. Karaharju Division of OrthorDaedic Surgerv and Traumatology, Surgical Hospital, Helsinki Summary
The compression obtained with external anchorage in the anterior and posterior part of the pelvic girdle has been studied with a measuring device in the sacroiliac joint and the symphysis of a specimen pelvis. Two models of external frames were tested, in both of which anchorage to the pelvic bone was brought about with 3 pins inserted in the iliac crests. The results were best with a trapezoid frame and bar exerting a compressive force on the pelvic girdle. When mounted with an inclination of 70” to the long axis of the body, the frame exerted considerable compression on the posterior part of the pelvic girdle. This mounting afforded good stability of the detached hemipelvis. The trapezoid compression frame is recommended as an alternative to conventional methods of treating unstable fractures and dislocations of the pelvic girdle.
FRACTURESof the pelvis arise from severe blunt impact on the pelvic girdle, most frequently in road-traffic accidents, free falls and crushing injuries in heavy industry. A considerable number of fractures involve both the anterior third of the pelvic girdle and the posterior, weight-bearing area. More than half the severe injuries to the pelvic girdle are associated with injuries elsewhere (Froman and Stein, 1967; Dunn and Morris, 1968; Slltis and Huittinen, 1972). In the treatment of pelvic fractures and dislocations, attention should be focused mainly on alignment of the posterior, weight-bearing area, because injuries to the sacro-iliac joint and adjacent parts of the sacrum and ilium are more apt to give rise to persistent disability than injury to the anterior third of the pelvis. The main object of treatment should therefore be accurate consolidation of all fractures in the weight-bearing area. To achieve this, nonoperative methods have hitherto been employed.
Current traction,
methods overhead
of treatment include skeletal pelvic slings or a combination
of these (Holdsworth, 1948 ; Dunn and Morris, 1968; Flynn, 1973). Maintenance of the fracture position is often difficult, treatment in traction and pelvic slings is cumbersome to the patient, and, consequently, there is a trend towards more active methods of treatment. Recently, the increasing use of external anchorage of fractures (Connes, 1973) has suggested the use of osteotaxis in pelvic fractures. The principle of external fixation of the pelvis is the assembling of a metallic frame, which is anchored to the pelvic girdle with pins inserted in the iliac crests. External fixation of pelvic fractures has been used by Carabalona et al. (1973) and Connes (1973). Since the technique of external fixation of the pelvic girdle is still unsettled and few reports are available regarding the stability achieved with external fixation, an experimental study was made. The results indicate that an unstable pelvic girdle may be sufficiently stabilized with external frames and that a considerable amount of compression may be conveyed to the pelvic girdle provided that the frame is properly assembled. METHODS The pelvic girdle of a 30-year-old maIe, suddenly deceased, was used for the measurements. All soft tissues were removed except for theligaments. The symphysis and the left sacro-iliac joint were transected, thus providing a test mode1 closely resembling a traumatic dislocation of the hemipelvis with injury to the symphysis and sacro-iliac joint. The two halves of the pelvic girdle were re-adapted with an external frame assembled with the Hoffmann instruments (Connes, 1973).
54
Different models of external fixation frames were constructed and subsequently tested. All mountings were anchored to the pelvic girdle with 3 pins inserted in the iliac crest. The aim was to achieve stability of the pelvic girdle by exerting compression on the pelvic joints. The compressive force exerted on the surfaces in the symphysis and the sacro-iliac joint through the external frame was measured with small mercuryfilled rubber balloons placed between the surfaces (Fig. 1). The balloons were connected to a horizontal cylinder containing an indicator piston. Stopcocks were inserted between the balloons and the cylinder, so that measurements could be made separately for the symphysis and the sacro-iliac joint. Compression of the pelvis squeezed mercury into the cylinder and caused movement of the piston; counterpressure was then exerted with a moveable vertical tube filled with mercury
Injury: the British Journal of Accident
and the external each experiment.
fixation
RESULTS Single compression
Surgery Vol. ~/NO. 1
re-assembled
between
bar
Sufficient stabilization of the pelvic girdle could not be achieved with a single compression bar. Redislocation of the hemipelvis occurred, and no measurable compression could be demonstrated in the symphysis or the sacro-iliac joint.
Trapezoid
compression
frame
The frame mounted at an inclination of 120” to the long axis of the body afforded reasonable stability of the pelvic girdle when a small amount of force was applied to the transverse compression bar of the frame. The compression force recorded was slightly higher in the sacroiliac joint than in the symphysis. Any further
Fig. 1. Measuring device. Mercury-filled rubber balloons were placed in the symphysis and sacro-iliac joint (a). The balloons were connected to an indicator piston (b) in a horizontal cylinder. The pressure was measured by equilibrating the pressure in the balloons with a moveable vertical mercury-filled tube (c).
until the indicator mark on the piston returned to its initial position. The following external mounting frames were used: a single transverse compression bar connecting the iliac crests, tested with the connectors inclined to the long axis of the body at 120” and 70”; a trapezoid compression frame (Fig. 2), tested with the connector bars inclined to the long axis of the body at 120” and 70”. Three measurements were made with each frame model, the frame being completely removed
increase of force, however, dislocated the hemipelvis, after which the pelvic girdle was unstable and the compression recordings from the balloons fell to zero. The frame mounted at an inclination of 70” to the long axis of the body conferred good stability on the pelvic girdle. In this position the compression force exerted by the transverse bar was directed on to the sacro-iliac joints. A gradual increase of strain on the compression bar of the frame produced a gradual pressure increase in
SICtis and Karaharju
: Trapezoid
the sacro-iliac joints were slightly higher the symphysis (Fig. model did not occur, force was applied the frame.
Compression
Frame
and symphysis. The forces in the posterior joint than in 3). Dislocation of the test despite the fact that enough to bend the metal bars of
b
a Fig. 2. Trapezoid
compression frame. The frame consists of 2 connector bars fixed to the iliac crests with 3 pin and 2 transverse bars. a, The compression bar midway between the iliac crests and the top of the frame allows firm compression on the pelvic girdle. b, The inclination of the frame is 70 degrees to the long axis of the body.
If the compression bar of the frame was mounted midway between the iliac crest and the top of the frame, recordings on the compression indicator on the bar were close to the actual pressures measured in the sacro-iliac joint.
connected to the iliac crest with 3 pins. With this technique, 8 kg of compression was measured in the sacro-iliac joint and 11 kg in the symphysis.
DISCUSSION The present study shows that considerable stability of the pelvic girdle can be achieved by external fixation. The results indicate that compression has to be applied to the posterior part of the pelvis for maximum stability of the pelvic girdle. This is easily achieved if the inclination of the compression frame is adjusted in such a way that the frame is aligned with the sacro-iliac joint (Fig. 2b). Carabalona et al. (1973) reported the results of electromagnetic measurements of compression forces in the pelvic girdle in connection with the use of different external frames. The most stable mounting in their series was a quadrilateral frame applied to the ventral aspect of the pelvis and
20
10
!
Fig. 3. Compression obtained in the sacro-iliac joint and symphysis with a trapezoid compression frame.
56
Injury: the British Journal of Accident Surgery Vol. ~/NO. 1
Our experience with the trapezoid compression frame in clinical practice has been rewarding (Fig. 4): it is easy to assemble, provides a painfree and stable fracture area, and greatly facilitates nursing. REFERENCES
CARABALONA P., RABICHONG P., BONNEL F., PERRUCHONE. and PEGURETF. (1973) Apports du fixateur externe dans les dislocations du pubis et de l’articulation sacro-iliaque. Montpelier Chir. 29,61. CONNESH. (1973) Hoffmann’s Double Frame External Paris, Gead. Anchorage. DUNN W. and MORRIS H. D. (1968) Fractures and dislocations of the pelvis. J. Bone Joint Surg. 50A, 1639.
FLYNN M. (1973) Disruption of symphysis pubis while horse riding: a report of two cases. Znjury 4, 357.
FROMANC. and STEINA. (1967) Complicated crushing injuries of the pelvis. J. Bone Joint Surg. 49B, 24. HOLDSWORTHF. W. (1948) Dislocation and fracturedislocation of the pelvis. J. Bone Joint Surg. 30B, 46 I. SL.XTISP. and HUITTINENV-M. (1972) Double vertical fractures of the pelvis. Acta Chir. &and. 138, 799.
b
c
Fig. 4. a, A 54-year-old building labourer
sustained a double vertical fracture of the pelvic girdle in a traffic accident. The injury comprised separation of the left sacro-iliac joint and fractures of both pubic rami on the left side. The pelvis was unstable. b, Reduction of the fracture-dislocation was achieved under general anaesthesia and re-alignment was maintained with the trapezoid compression frame. Relief from pain was obtained, and weight-bearing on crutches was initiated 3 weeks later. The compression frame was removed 6 weeks after the accident. c, At follow-up 6 months later, radiographs revealed solid union of the fracture-dislocation. The pelvic girdle was stable. for reprints should be addressed to: Dr PPr Slltis, Division of Orthopaedic Surgery and Traumatology, Kasarmikatu 11-13, 00130 Helsinki 13, Finland.
Requests
Surgical Hospital,
53
7, 53-56
External fixation of the pelvic girdle with a trapezoid compression frame P3r Skitis and Erkki 0. Karaharju Division of OrthorDaedic Surgerv and Traumatology, Surgical Hospital, Helsinki Summary
The compression obtained with external anchorage in the anterior and posterior part of the pelvic girdle has been studied with a measuring device in the sacroiliac joint and the symphysis of a specimen pelvis. Two models of external frames were tested, in both of which anchorage to the pelvic bone was brought about with 3 pins inserted in the iliac crests. The results were best with a trapezoid frame and bar exerting a compressive force on the pelvic girdle. When mounted with an inclination of 70” to the long axis of the body, the frame exerted considerable compression on the posterior part of the pelvic girdle. This mounting afforded good stability of the detached hemipelvis. The trapezoid compression frame is recommended as an alternative to conventional methods of treating unstable fractures and dislocations of the pelvic girdle.
FRACTURESof the pelvis arise from severe blunt impact on the pelvic girdle, most frequently in road-traffic accidents, free falls and crushing injuries in heavy industry. A considerable number of fractures involve both the anterior third of the pelvic girdle and the posterior, weight-bearing area. More than half the severe injuries to the pelvic girdle are associated with injuries elsewhere (Froman and Stein, 1967; Dunn and Morris, 1968; Slltis and Huittinen, 1972). In the treatment of pelvic fractures and dislocations, attention should be focused mainly on alignment of the posterior, weight-bearing area, because injuries to the sacro-iliac joint and adjacent parts of the sacrum and ilium are more apt to give rise to persistent disability than injury to the anterior third of the pelvis. The main object of treatment should therefore be accurate consolidation of all fractures in the weight-bearing area. To achieve this, nonoperative methods have hitherto been employed.
Current traction,
methods overhead
of treatment include skeletal pelvic slings or a combination
of these (Holdsworth, 1948 ; Dunn and Morris, 1968; Flynn, 1973). Maintenance of the fracture position is often difficult, treatment in traction and pelvic slings is cumbersome to the patient, and, consequently, there is a trend towards more active methods of treatment. Recently, the increasing use of external anchorage of fractures (Connes, 1973) has suggested the use of osteotaxis in pelvic fractures. The principle of external fixation of the pelvis is the assembling of a metallic frame, which is anchored to the pelvic girdle with pins inserted in the iliac crests. External fixation of pelvic fractures has been used by Carabalona et al. (1973) and Connes (1973). Since the technique of external fixation of the pelvic girdle is still unsettled and few reports are available regarding the stability achieved with external fixation, an experimental study was made. The results indicate that an unstable pelvic girdle may be sufficiently stabilized with external frames and that a considerable amount of compression may be conveyed to the pelvic girdle provided that the frame is properly assembled. METHODS The pelvic girdle of a 30-year-old maIe, suddenly deceased, was used for the measurements. All soft tissues were removed except for theligaments. The symphysis and the left sacro-iliac joint were transected, thus providing a test mode1 closely resembling a traumatic dislocation of the hemipelvis with injury to the symphysis and sacro-iliac joint. The two halves of the pelvic girdle were re-adapted with an external frame assembled with the Hoffmann instruments (Connes, 1973).
54
Different models of external fixation frames were constructed and subsequently tested. All mountings were anchored to the pelvic girdle with 3 pins inserted in the iliac crest. The aim was to achieve stability of the pelvic girdle by exerting compression on the pelvic joints. The compressive force exerted on the surfaces in the symphysis and the sacro-iliac joint through the external frame was measured with small mercuryfilled rubber balloons placed between the surfaces (Fig. 1). The balloons were connected to a horizontal cylinder containing an indicator piston. Stopcocks were inserted between the balloons and the cylinder, so that measurements could be made separately for the symphysis and the sacro-iliac joint. Compression of the pelvis squeezed mercury into the cylinder and caused movement of the piston; counterpressure was then exerted with a moveable vertical tube filled with mercury
Injury: the British Journal of Accident
and the external each experiment.
fixation
RESULTS Single compression
Surgery Vol. ~/NO. 1
re-assembled
between
bar
Sufficient stabilization of the pelvic girdle could not be achieved with a single compression bar. Redislocation of the hemipelvis occurred, and no measurable compression could be demonstrated in the symphysis or the sacro-iliac joint.
Trapezoid
compression
frame
The frame mounted at an inclination of 120” to the long axis of the body afforded reasonable stability of the pelvic girdle when a small amount of force was applied to the transverse compression bar of the frame. The compression force recorded was slightly higher in the sacroiliac joint than in the symphysis. Any further
Fig. 1. Measuring device. Mercury-filled rubber balloons were placed in the symphysis and sacro-iliac joint (a). The balloons were connected to an indicator piston (b) in a horizontal cylinder. The pressure was measured by equilibrating the pressure in the balloons with a moveable vertical mercury-filled tube (c).
until the indicator mark on the piston returned to its initial position. The following external mounting frames were used: a single transverse compression bar connecting the iliac crests, tested with the connectors inclined to the long axis of the body at 120” and 70”; a trapezoid compression frame (Fig. 2), tested with the connector bars inclined to the long axis of the body at 120” and 70”. Three measurements were made with each frame model, the frame being completely removed
increase of force, however, dislocated the hemipelvis, after which the pelvic girdle was unstable and the compression recordings from the balloons fell to zero. The frame mounted at an inclination of 70” to the long axis of the body conferred good stability on the pelvic girdle. In this position the compression force exerted by the transverse bar was directed on to the sacro-iliac joints. A gradual increase of strain on the compression bar of the frame produced a gradual pressure increase in
SICtis and Karaharju
: Trapezoid
the sacro-iliac joints were slightly higher the symphysis (Fig. model did not occur, force was applied the frame.
Compression
Frame
and symphysis. The forces in the posterior joint than in 3). Dislocation of the test despite the fact that enough to bend the metal bars of
b
a Fig. 2. Trapezoid
compression frame. The frame consists of 2 connector bars fixed to the iliac crests with 3 pin and 2 transverse bars. a, The compression bar midway between the iliac crests and the top of the frame allows firm compression on the pelvic girdle. b, The inclination of the frame is 70 degrees to the long axis of the body.
If the compression bar of the frame was mounted midway between the iliac crest and the top of the frame, recordings on the compression indicator on the bar were close to the actual pressures measured in the sacro-iliac joint.
connected to the iliac crest with 3 pins. With this technique, 8 kg of compression was measured in the sacro-iliac joint and 11 kg in the symphysis.
DISCUSSION The present study shows that considerable stability of the pelvic girdle can be achieved by external fixation. The results indicate that compression has to be applied to the posterior part of the pelvis for maximum stability of the pelvic girdle. This is easily achieved if the inclination of the compression frame is adjusted in such a way that the frame is aligned with the sacro-iliac joint (Fig. 2b). Carabalona et al. (1973) reported the results of electromagnetic measurements of compression forces in the pelvic girdle in connection with the use of different external frames. The most stable mounting in their series was a quadrilateral frame applied to the ventral aspect of the pelvis and
20
10
!
Fig. 3. Compression obtained in the sacro-iliac joint and symphysis with a trapezoid compression frame.
56
Injury: the British Journal of Accident Surgery Vol. ~/NO. 1
Our experience with the trapezoid compression frame in clinical practice has been rewarding (Fig. 4): it is easy to assemble, provides a painfree and stable fracture area, and greatly facilitates nursing. REFERENCES
CARABALONA P., RABICHONG P., BONNEL F., PERRUCHONE. and PEGURETF. (1973) Apports du fixateur externe dans les dislocations du pubis et de l’articulation sacro-iliaque. Montpelier Chir. 29,61. CONNESH. (1973) Hoffmann’s Double Frame External Paris, Gead. Anchorage. DUNN W. and MORRIS H. D. (1968) Fractures and dislocations of the pelvis. J. Bone Joint Surg. 50A, 1639.
FLYNN M. (1973) Disruption of symphysis pubis while horse riding: a report of two cases. Znjury 4, 357.
FROMANC. and STEINA. (1967) Complicated crushing injuries of the pelvis. J. Bone Joint Surg. 49B, 24. HOLDSWORTHF. W. (1948) Dislocation and fracturedislocation of the pelvis. J. Bone Joint Surg. 30B, 46 I. SL.XTISP. and HUITTINENV-M. (1972) Double vertical fractures of the pelvis. Acta Chir. &and. 138, 799.
b
c
Fig. 4. a, A 54-year-old building labourer
sustained a double vertical fracture of the pelvic girdle in a traffic accident. The injury comprised separation of the left sacro-iliac joint and fractures of both pubic rami on the left side. The pelvis was unstable. b, Reduction of the fracture-dislocation was achieved under general anaesthesia and re-alignment was maintained with the trapezoid compression frame. Relief from pain was obtained, and weight-bearing on crutches was initiated 3 weeks later. The compression frame was removed 6 weeks after the accident. c, At follow-up 6 months later, radiographs revealed solid union of the fracture-dislocation. The pelvic girdle was stable. for reprints should be addressed to: Dr PPr Slltis, Division of Orthopaedic Surgery and Traumatology, Kasarmikatu 11-13, 00130 Helsinki 13, Finland.
Requests
Surgical Hospital,
