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THE RADIO-RADIAL EXTERNAL FIXATOR IN THE TREATMENT OF FRACTURES OF THE DISTAL RADIUS
THE RADIO-RADIAL EXTERNAL FIXATOR IN THE TREATMENT OF FRACTURES OF THE DISTAL RADIUS T. FISCHER, P. KOCH, C. SAAGER and G. N. KOHUT From the Department of Orthopaedic Surgery, HoÃpital Cantonal, Fribourg, Switzerland
The technique of radio-radial monobloc-fixation with the small AO external fixator device has been applied to 17 consecutive Colles' fractures. The fracture types were mainly A3 and C2, according to the AO classification. We found this technique to be easy and quick in application and stable in fixation. Direct, precise and atraumatic reduction can be achieved by using the distal pins as joy-sticks. Furthermore, disimpaction of the fracture to regain length is possible without bone grafting. Normal carpal mobility and load transfer is preserved during fracture healing and the injured hand can be used in daily life with certain restrictions. To prevent pin-track infections, early mobilization of the wrist should be avoided. We recommend this technique in the treatment of comminuted AO-type A3 fractures of the distal radius and in certain type C2 cases. Journal of Hand Surgery (British and European Volume, 1999) 24B: 5: 604±609
Loss of reduction and malunion are common problems in fractures of the distal radius (Jenkins,1989; Jupiter, 1991). Although the first description of an external fixator in the treatment of forearm fractures by OmbreÂdanne (1929) was of a radio-radial device, little attention has been paid to this technique until now. MeleÂndez et al. (1989), reporting 13 cases, found this technique to be stable and encouraged the patients to mobilize the wrist. The early functional result in their series was good but at the price of a very high incidence of pin-track infections in five patients out of 13. Kohut (1995) reported good results in two young patients and Bishay et al. (1994) reported exceptionally good results in 14 AO C2 and C3 fractures. Recently, Krishnan et al. (1998) presented good functional results in 22 patients with intraarticular fractures treated with this technique. In this paper we report our experience with this procedure.
PATIENTS AND METHODS In a retrospective analysis, we studied 17 closed, displaced and unstable fractures of the distal radius in 17 consecutive patients treated with a radio-radial external fixator with a minimal follow up of 12 months. Young patients with an open epiphysis were excluded. The age range was 14 to 83 years (mean, 46). Seven of the patients were between 14 and 19, the others over 46 years of age. Twelve were women and five men. One fracture resulted from high energy and 16 from low energy trauma. The fractures were classified according to the AO-classification. In 11 patients the fracture was AO type A3, but one C1 and four C2 fractures were also treated with the technique. Fifteen operations were done primarily. There were 16 closed reductions and one open. Five patients needed an additional local intervention: two had osteosynthesis of the ulnar styloid, two
Fig 1 Joy-stick manipulation allows direct, three-dimensional positioning of the articular plane by the distal pins. 604
RADIO-RADIAL EXTERNAL FIXATOR
had osteosynthesis of the distal ulna and one had release of the carpal tunnel.
METHOD Reduction and application of the small AO external fixator were done under brachial plexus or general anaesthesia in theatre under sterile conditions. Two 2.5 mm Schanz screws are inserted in the distal fragment through short skin incisions under X-ray control: one is
Fig 2 (a,b) Example of a fixator construction.
605
placed through Lister's tubercle and the other through the radial styloid. The pins are perpendicular to each other, parallel to the joint surface and placed in subchondral bone. Two other pins are inserted through two cortices in the distal radial diaphysis. In three cases with C2 fractures, this construction was completed by a third Schanz screw in the distal fragment and in two of them, an additional K-wire (1.2 mm) was used to stabilize the intraarticular fracture. In one case, a twopin construction was used, with one pin in the metaphysis and one in the diaphysis. To avoid lesions
606
of the superficial radial nerve, the subcutaneous tissue is divided carefully after skin incision and a tissue protector is used. The fracture is reduced by using the distal pins as joysticks (Fig 1), permitting easy and precise reduction of the articular fragment under X-ray control. The distal pins are connected to the proximal ones by carbon bars (Fig 2). An anterior splint is worn for 4 to 8 weeks to prevent pin-track infections. Gentle exercises of the wrist out of the plaster cast are permitted after 2 to 4 weeks. The
THE JOURNAL OF HAND SURGERY VOL. 24B No. 5 OCTOBER 1999
external fixator was removed at a mean of 6.5 weeks after surgery (range, 4±9 weeks). The mean period of clinical and radiological review was 29 months (range, 12±72 months). RESULTS Radiological outcome Radiographs were taken in two planes. Radial tilt, palmar tilt and radial length were measured on the post
Fig 3 Radial fracture in a 69-year-old woman with moderate osteoporosis. (a,b) Posteroanterior and lateral X-rays before closed reduction and four pin fixator construction of the radial fracture. (c,d) Before fixator removal at 6.5 weeks and (e,f ) review at 22 months.
RADIO-RADIAL EXTERNAL FIXATOR
607
Fig 3 (continued )
reduction X-ray and at the last follow-up. The mean radial tilt after reduction was 238 (range, 15±288) and 248 (range, 14±308) at the later review. The mean anterior tilt was 128 (range, 2±248) postoperatively and 128 (range, 4±268) at the later review. Radial length, with reference to the ulna, was between 73 to 5 mm (mean, 1 mm after reduction and 73 to 3 mm (mean, 0 mm) at late review. A typical example is shown in Figure 3. Clinical outcome At the late review, four patients complained of pain at the fracture area during changes in weather. One reported slight pain in the radiocarpal area when mountain climbing. All patients had regained their preinjury level of activities except for one who had limited action in the extensor pollicis longus (EPL). Complications There was one pin-track infection with loosening and two pin-track irritations that healed within a week by correct pin-care without any antibiotics. There was one
tenodesis of the EPL tendon with partial recovery. One reoperation was necessary after inadequate primary reduction. The same patient sustained a fracture at the site of the distal diaphyseal pin-hole in a ski accident 7 months after primary treatment. There was no cases of reflex sympathetic dystrophy (RSD) and, even in porotic bone, there was no aseptic pin loosening. One patient had a primary release of the carpal tunnel for a median nerve injury, with complete recovery by 6 weeks after operation. DISCUSSION The aim of treatment of fractures of the distal radius is the restoration of an anatomical position. Several authors have described a significant correlation of radiological and clinical results after treatment of Colles' fractures: Bickerstaff and Bell (1989) found dorsal displacement to be the main reason for morbidity after this injury. Cooney et al. (1980) reported incomplete restoration of radial length or secondary loss of reduction to be the main reasons for complications in Colles' fractures. Taleisnik and Watson (1984) described
608
Fig 3 (continued )
THE JOURNAL OF HAND SURGERY VOL. 24B No. 5 OCTOBER 1999
RADIO-RADIAL EXTERNAL FIXATOR
symptomatic midcarpal instability, caused by malunited fractures of the distal radius. They suggested that loss of the Palmar tilt of the distal articular surface of the radius positions the carpus in a dorsal collapse malalignment. Biomechanical studies by Short et al. (1987) have shown that the contact area between the carpus and the articular surface of the radius decreases in size and shifts dorsally when there is loss of anterior inclination of the distal radius. In addition, increase in the load on the ulnocarpal joint is correlated with the dorsal tilt. Jenkins (1989) coined the expression of ``chronic instability in Colles' fractures''. He found significant late secondary loss of position in 115 fractures treated conservatively until consolidation. The extent of collapse was determined solely by the initial deformity and was not related to either intraarticular involvement or the presence of radiographically visible comminution. He found a mean increase of 88 in dorsal angulation, a mean loss of 68 in radial angle and 3 mm of radial shortening. In our series, we found that there was good stabilization of Colles' fractures by the radio-radial external fixator. We observed a mean decrease of 18 in dorsal angulation, 18 loss of radial tilt and 1 mm of radial length. MeleÂndez et al. (1989) reported a high incidence of pin-track infections in a series of 13 patients who had mobilization under the supervision of a physiotherapist. Krishnan et al. (1998) documented better results with the same regimen but with the addition of a 1 week prophylactic course of oral antibiotic. In our series there was one case of pin-track infection, even though prophylactic antibiotics were not prescribed in all cases, and given as a single dose when used. We believe that additional immobilization of the wrist by an anterior splint is important to avoid this complication but mobilization out of the splint is permitted. The aim of this treatment is stable fixation and not full mobilization of the wrist in the healing period. Combalia and Suso (1994), Cronier et al. (1991) and Kaempffe et al. (1993) discuss the role of distraction of the carpus by radiometacarpal external fixation as a trigger for RSD. Kaempffe et al. (1993) found that scores for pain, function, wrist motion and grip strength decreased in proportion to the increase in the carpal height index by distraction. The outcome was adversely affected with increasing duration of distraction. Traumatic reduction of the fracture has been postulated to be another trigger for RSD in fractures of the distal radius. Treatment by the radio-radial device permits normal carpal mobility and load transfer during the period of stabilization. Carpal ligaments are not affected by this
609
construction, even when the fracture is distracted. The trauma of reduction is low because there is direct manipulation of the fragments by the pins. In our small series there was no RSD. A danger of this technique is overcorrection of the distal radius, particularly the anterior tilt, which occurred in one case. Projection of the fixator pins through the distal fragment is an important disadvantage of this technique (Fig 3). However the intraoperative reduction can easily be checked by X-ray control. The complication rate in our series was very low. Low grade osteomyelitis after chronic pin-track infection and tenodesis of the EPL in a 46-year-old women was the most severe problem. Correct pin-track care is essential to avoid pin-track infection. Weakening of the diaphyseal bone by pin holes is well known. There was one fracture at a pin site following a fall when skiing. References Bickerstaff DR, Bell MJ (1989). Carpal malalignment in Colles' fractures. Journal of Hand Surgery, 14B: 155±160. Bishay M, Aguilera X, Grant J, Dunkerley DR (1994). The results of external fixation of the radius in the treatment of comminuted intraarticular fractures of the distal end. Journal of Hand Surgery, 19B: 378±383. Combalia A, Suso S (1994). Reflex sympathetic dystrophy in severe fractures of the distal radius treated with distraction devices. Journal of Hand Surgery, 19A: 156±157. Cooney WP, Dobyns JH, Linscheid RL (1980). Complications of Colles' fractures. Journal of Bone and Joint Surgery, 62A: 613±619. Cronier P, Talha A, Toulemonde JL, Jaeger F, Guntz M (1991). ReÂsultats de la distraction par fixateur externe metacarporadial dans les fractures de l'extreÂmite distale du radius. Journal de Chirurgie, 128: 8±12. Jenkins NH (1989). The unstable Colles' fracture. Journal of Hand Surgery, 14B: 149±154. Jupiter JB (1991). Fractures of the distal end of the radius. Journal of Bone and Joint Surgery, 73A: 461±469. Kaempffe FA, Wheeler DR, Peimer CA, Hvisdak KS, Ceravolo J, Senal J (1993). Severe fractures of the distal radius: effect of amount and duration of external fixator distraction on outcome. Journal of Hand Surgery, 18A: 33±41. Kohut GN (1995). Extra-articular fractures of the distal radius in young adults. A technique of closed reduction and stabilization by mono-segmental, radio-radial external fixator. Annales de Chirurgie de la Main, 14: 14±19. Krishnan J, Chipchase LS, Slavotinek J (1998). Intraarticular fractures of the distal radius treated with metaphyseal external fixation. Journal of Hand Surgery, 23B: 396±399. MeleÂndez EM, Mehne DK, Posner MA (1989). Treatment of unstable Colles' fractures with a new radius mini-fixator. Journal of Hand Surgery, 14A: 807±811. OmbreÂdanne L (1929). L'osteÂosyntheÁse temporaire chez les enfants. Presse MeÂdicale, 52: 845±848. Short WH, Palmer AK, Werner FW, Murphy DJ (1987). A biomechanical study of distal radial fractures. Journal of Hand Surgery, 12A: 529±534. Taleisnik J, Watson HK (1984). Midcarpal instability caused by malunited fractures of the distal radius. Journal of Hand Surgery, 9A: 350±357. Received: 20 October 1998 Accepted after revision: 7 June 1999 T. Fischer MD, Department of Hand and Plastic Surgery, Kantonsspital Aarau, 5000 Aarau, Switzerland. E-mail: [email protected] # 1999 The British Society for Surgery of the Hand Article no. jhsb.1999.0256
The technique of radio-radial monobloc-fixation with the small AO external fixator device has been applied to 17 consecutive Colles' fractures. The fracture types were mainly A3 and C2, according to the AO classification. We found this technique to be easy and quick in application and stable in fixation. Direct, precise and atraumatic reduction can be achieved by using the distal pins as joy-sticks. Furthermore, disimpaction of the fracture to regain length is possible without bone grafting. Normal carpal mobility and load transfer is preserved during fracture healing and the injured hand can be used in daily life with certain restrictions. To prevent pin-track infections, early mobilization of the wrist should be avoided. We recommend this technique in the treatment of comminuted AO-type A3 fractures of the distal radius and in certain type C2 cases. Journal of Hand Surgery (British and European Volume, 1999) 24B: 5: 604±609
Loss of reduction and malunion are common problems in fractures of the distal radius (Jenkins,1989; Jupiter, 1991). Although the first description of an external fixator in the treatment of forearm fractures by OmbreÂdanne (1929) was of a radio-radial device, little attention has been paid to this technique until now. MeleÂndez et al. (1989), reporting 13 cases, found this technique to be stable and encouraged the patients to mobilize the wrist. The early functional result in their series was good but at the price of a very high incidence of pin-track infections in five patients out of 13. Kohut (1995) reported good results in two young patients and Bishay et al. (1994) reported exceptionally good results in 14 AO C2 and C3 fractures. Recently, Krishnan et al. (1998) presented good functional results in 22 patients with intraarticular fractures treated with this technique. In this paper we report our experience with this procedure.
PATIENTS AND METHODS In a retrospective analysis, we studied 17 closed, displaced and unstable fractures of the distal radius in 17 consecutive patients treated with a radio-radial external fixator with a minimal follow up of 12 months. Young patients with an open epiphysis were excluded. The age range was 14 to 83 years (mean, 46). Seven of the patients were between 14 and 19, the others over 46 years of age. Twelve were women and five men. One fracture resulted from high energy and 16 from low energy trauma. The fractures were classified according to the AO-classification. In 11 patients the fracture was AO type A3, but one C1 and four C2 fractures were also treated with the technique. Fifteen operations were done primarily. There were 16 closed reductions and one open. Five patients needed an additional local intervention: two had osteosynthesis of the ulnar styloid, two
Fig 1 Joy-stick manipulation allows direct, three-dimensional positioning of the articular plane by the distal pins. 604
RADIO-RADIAL EXTERNAL FIXATOR
had osteosynthesis of the distal ulna and one had release of the carpal tunnel.
METHOD Reduction and application of the small AO external fixator were done under brachial plexus or general anaesthesia in theatre under sterile conditions. Two 2.5 mm Schanz screws are inserted in the distal fragment through short skin incisions under X-ray control: one is
Fig 2 (a,b) Example of a fixator construction.
605
placed through Lister's tubercle and the other through the radial styloid. The pins are perpendicular to each other, parallel to the joint surface and placed in subchondral bone. Two other pins are inserted through two cortices in the distal radial diaphysis. In three cases with C2 fractures, this construction was completed by a third Schanz screw in the distal fragment and in two of them, an additional K-wire (1.2 mm) was used to stabilize the intraarticular fracture. In one case, a twopin construction was used, with one pin in the metaphysis and one in the diaphysis. To avoid lesions
606
of the superficial radial nerve, the subcutaneous tissue is divided carefully after skin incision and a tissue protector is used. The fracture is reduced by using the distal pins as joysticks (Fig 1), permitting easy and precise reduction of the articular fragment under X-ray control. The distal pins are connected to the proximal ones by carbon bars (Fig 2). An anterior splint is worn for 4 to 8 weeks to prevent pin-track infections. Gentle exercises of the wrist out of the plaster cast are permitted after 2 to 4 weeks. The
THE JOURNAL OF HAND SURGERY VOL. 24B No. 5 OCTOBER 1999
external fixator was removed at a mean of 6.5 weeks after surgery (range, 4±9 weeks). The mean period of clinical and radiological review was 29 months (range, 12±72 months). RESULTS Radiological outcome Radiographs were taken in two planes. Radial tilt, palmar tilt and radial length were measured on the post
Fig 3 Radial fracture in a 69-year-old woman with moderate osteoporosis. (a,b) Posteroanterior and lateral X-rays before closed reduction and four pin fixator construction of the radial fracture. (c,d) Before fixator removal at 6.5 weeks and (e,f ) review at 22 months.
RADIO-RADIAL EXTERNAL FIXATOR
607
Fig 3 (continued )
reduction X-ray and at the last follow-up. The mean radial tilt after reduction was 238 (range, 15±288) and 248 (range, 14±308) at the later review. The mean anterior tilt was 128 (range, 2±248) postoperatively and 128 (range, 4±268) at the later review. Radial length, with reference to the ulna, was between 73 to 5 mm (mean, 1 mm after reduction and 73 to 3 mm (mean, 0 mm) at late review. A typical example is shown in Figure 3. Clinical outcome At the late review, four patients complained of pain at the fracture area during changes in weather. One reported slight pain in the radiocarpal area when mountain climbing. All patients had regained their preinjury level of activities except for one who had limited action in the extensor pollicis longus (EPL). Complications There was one pin-track infection with loosening and two pin-track irritations that healed within a week by correct pin-care without any antibiotics. There was one
tenodesis of the EPL tendon with partial recovery. One reoperation was necessary after inadequate primary reduction. The same patient sustained a fracture at the site of the distal diaphyseal pin-hole in a ski accident 7 months after primary treatment. There was no cases of reflex sympathetic dystrophy (RSD) and, even in porotic bone, there was no aseptic pin loosening. One patient had a primary release of the carpal tunnel for a median nerve injury, with complete recovery by 6 weeks after operation. DISCUSSION The aim of treatment of fractures of the distal radius is the restoration of an anatomical position. Several authors have described a significant correlation of radiological and clinical results after treatment of Colles' fractures: Bickerstaff and Bell (1989) found dorsal displacement to be the main reason for morbidity after this injury. Cooney et al. (1980) reported incomplete restoration of radial length or secondary loss of reduction to be the main reasons for complications in Colles' fractures. Taleisnik and Watson (1984) described
608
Fig 3 (continued )
THE JOURNAL OF HAND SURGERY VOL. 24B No. 5 OCTOBER 1999
RADIO-RADIAL EXTERNAL FIXATOR
symptomatic midcarpal instability, caused by malunited fractures of the distal radius. They suggested that loss of the Palmar tilt of the distal articular surface of the radius positions the carpus in a dorsal collapse malalignment. Biomechanical studies by Short et al. (1987) have shown that the contact area between the carpus and the articular surface of the radius decreases in size and shifts dorsally when there is loss of anterior inclination of the distal radius. In addition, increase in the load on the ulnocarpal joint is correlated with the dorsal tilt. Jenkins (1989) coined the expression of ``chronic instability in Colles' fractures''. He found significant late secondary loss of position in 115 fractures treated conservatively until consolidation. The extent of collapse was determined solely by the initial deformity and was not related to either intraarticular involvement or the presence of radiographically visible comminution. He found a mean increase of 88 in dorsal angulation, a mean loss of 68 in radial angle and 3 mm of radial shortening. In our series, we found that there was good stabilization of Colles' fractures by the radio-radial external fixator. We observed a mean decrease of 18 in dorsal angulation, 18 loss of radial tilt and 1 mm of radial length. MeleÂndez et al. (1989) reported a high incidence of pin-track infections in a series of 13 patients who had mobilization under the supervision of a physiotherapist. Krishnan et al. (1998) documented better results with the same regimen but with the addition of a 1 week prophylactic course of oral antibiotic. In our series there was one case of pin-track infection, even though prophylactic antibiotics were not prescribed in all cases, and given as a single dose when used. We believe that additional immobilization of the wrist by an anterior splint is important to avoid this complication but mobilization out of the splint is permitted. The aim of this treatment is stable fixation and not full mobilization of the wrist in the healing period. Combalia and Suso (1994), Cronier et al. (1991) and Kaempffe et al. (1993) discuss the role of distraction of the carpus by radiometacarpal external fixation as a trigger for RSD. Kaempffe et al. (1993) found that scores for pain, function, wrist motion and grip strength decreased in proportion to the increase in the carpal height index by distraction. The outcome was adversely affected with increasing duration of distraction. Traumatic reduction of the fracture has been postulated to be another trigger for RSD in fractures of the distal radius. Treatment by the radio-radial device permits normal carpal mobility and load transfer during the period of stabilization. Carpal ligaments are not affected by this
609
construction, even when the fracture is distracted. The trauma of reduction is low because there is direct manipulation of the fragments by the pins. In our small series there was no RSD. A danger of this technique is overcorrection of the distal radius, particularly the anterior tilt, which occurred in one case. Projection of the fixator pins through the distal fragment is an important disadvantage of this technique (Fig 3). However the intraoperative reduction can easily be checked by X-ray control. The complication rate in our series was very low. Low grade osteomyelitis after chronic pin-track infection and tenodesis of the EPL in a 46-year-old women was the most severe problem. Correct pin-track care is essential to avoid pin-track infection. Weakening of the diaphyseal bone by pin holes is well known. There was one fracture at a pin site following a fall when skiing. References Bickerstaff DR, Bell MJ (1989). Carpal malalignment in Colles' fractures. Journal of Hand Surgery, 14B: 155±160. Bishay M, Aguilera X, Grant J, Dunkerley DR (1994). The results of external fixation of the radius in the treatment of comminuted intraarticular fractures of the distal end. Journal of Hand Surgery, 19B: 378±383. Combalia A, Suso S (1994). Reflex sympathetic dystrophy in severe fractures of the distal radius treated with distraction devices. Journal of Hand Surgery, 19A: 156±157. Cooney WP, Dobyns JH, Linscheid RL (1980). Complications of Colles' fractures. Journal of Bone and Joint Surgery, 62A: 613±619. Cronier P, Talha A, Toulemonde JL, Jaeger F, Guntz M (1991). ReÂsultats de la distraction par fixateur externe metacarporadial dans les fractures de l'extreÂmite distale du radius. Journal de Chirurgie, 128: 8±12. Jenkins NH (1989). The unstable Colles' fracture. Journal of Hand Surgery, 14B: 149±154. Jupiter JB (1991). Fractures of the distal end of the radius. Journal of Bone and Joint Surgery, 73A: 461±469. Kaempffe FA, Wheeler DR, Peimer CA, Hvisdak KS, Ceravolo J, Senal J (1993). Severe fractures of the distal radius: effect of amount and duration of external fixator distraction on outcome. Journal of Hand Surgery, 18A: 33±41. Kohut GN (1995). Extra-articular fractures of the distal radius in young adults. A technique of closed reduction and stabilization by mono-segmental, radio-radial external fixator. Annales de Chirurgie de la Main, 14: 14±19. Krishnan J, Chipchase LS, Slavotinek J (1998). Intraarticular fractures of the distal radius treated with metaphyseal external fixation. Journal of Hand Surgery, 23B: 396±399. MeleÂndez EM, Mehne DK, Posner MA (1989). Treatment of unstable Colles' fractures with a new radius mini-fixator. Journal of Hand Surgery, 14A: 807±811. OmbreÂdanne L (1929). L'osteÂosyntheÁse temporaire chez les enfants. Presse MeÂdicale, 52: 845±848. Short WH, Palmer AK, Werner FW, Murphy DJ (1987). A biomechanical study of distal radial fractures. Journal of Hand Surgery, 12A: 529±534. Taleisnik J, Watson HK (1984). Midcarpal instability caused by malunited fractures of the distal radius. Journal of Hand Surgery, 9A: 350±357. Received: 20 October 1998 Accepted after revision: 7 June 1999 T. Fischer MD, Department of Hand and Plastic Surgery, Kantonsspital Aarau, 5000 Aarau, Switzerland. E-mail: [email protected] # 1999 The British Society for Surgery of the Hand Article no. jhsb.1999.0256