620
Proc. roy. Soc. Med. Volume 70 September 1977
Section of Orthopadics President G C Lloyd Roberts Mch
Meeting I February 1977
The Elbow Joint Mr T M BucknilH (East Birmingham Hospital, Bordesley Green East, Birmingham B9 SST)
Anterior Dislocation of the Radial Head in Children
Established dislocation of the head of the radius is an uncommon but important feature of elbow and forearm injuries in children. Young children adapt so easily to forearm disability that despite retricted movements, subjective symptoms are often minimal. Parental concern over a child with a dislocated radial head may not be aroused until growth increases deformity and disability. Similarly, a forearm anomaly may remain unnoticed until a minor elbow injury draws attentionto a long established deformity, and with pain, swelling and an abnormal X-ray, the distinction between congenital and traumatic elbow lesions is easily confused. The susceptibility of the radial head to subluxation and less commonly to dislocation in young children is well recognized, but generally there has been a cautious and guarded approach to surgical correction of the displaced radial head. Orthop2dic literature has focused intermittent interest over the years in the isolated radial head dislocation but case numbers have been few, and impressions often inconclusive. Mostly these reports have described radial head dislocations presumed to be of congenital origin more from lack of any known trauma than from specific clinical features. The distortion of elbow anatomy associated with a congenital anomaly must certainly influence any attempt at reduction or reconstruction of an elbow and the distinction between congenital and traumatic lesions is of considerable importance. Several well recognized syndromes and skeletal anomalies in children include radial head dis-
Fig I Traumatic radial head dislocation of radial head in a child of 3 years showing para-articular ossification
Section of Orthopadics
location as one of their features. Almquist et al. (1969) reviewed congenital radial head problems and listed ten primary conditions in which radial head dislocation had been previously noted and added four further conditions. Generally, congenital head dislocations seen with multiple anomalies are typically posterior and bilateral. In their review of 18 children with congenital dislocations Almquist et al. (1969) reported only 4 isolated radial dislocations and these were all posterior. The classic description of features of the congenitally dislocated radial head was made by Mcfarland in 1936. He reported 11 cases of anterior radial dislocation and emphasized radiological features that he considered to be specific to congenital lesions. These referred mainly to an elliptical deformed radial head and a dysplastic capitellum. Concavity of the posterior border of the proximal ulna and para-articular ossification were additional features (Fig 1). Since Mcfarland's original description, further cases of isolated dislocations of the radial head have been reported at intervals.
621
White (1943) added cases and Magee (1947) described a bilateral case. Smith (1949) reviewed 5 cases and Caravias (1957) reviewed 3. In 1965 Schubert described a case of radial head dislocation in a neonate, which he was able to reduce and maintain adequately stable. Cockshutt & Omolulu (1958) reported a neonate with bilateral recurrent anterior dislocation of the radial heads, indicating marked radioulnar instability.
Clinical Material. In this review, 28 children with isolated unilateral radial head dislocation have been assessed. Many have shown features described by Mcfarland as typically congenital in origin but only 5 of these gave no history of trauma, and their deformities were indistinguishable from the others. The time lapse from injury to presentation varied from three months to eleven years with an average of three years. Often the injury had been previously diagnosed as a contusion or sprain and the arm supported in a sling until comfortable. Over one-third of those with a history of injury had undergone clinical and radiographic examination
Fig 2 Anterior radial head dislocation with ulnar bowing three years after injury
622
Proc. roy. Soc. Med. Volume 70 September 1977
at the time of injury, however, the lesion had escaped detection. Some months later, when the elbow remained deformed and movements restricted, the parents sought further advice. Average age at injury was 7j years. Accurate assessment of the original injuries in this review was not possible. However, 11 of the 28 showed angulation of the proximal ulna indicating malunion following a Monteggia lesion. Fig 2 shows anterior radial head dislocation with ulnar bowing. Consistently, the affected elbows showed some restriction of movements, most commonly in flexion and pronation. An increased carrying angle was noted in 12 of the elbows, with valgus instability in 11 of these. Varus angulation was noted in 6 elbows and Fig 3 Drawing showing a strip of tendon from the lateral corresponded to varus malunion of the proximal border of triceps used to reconstruct the annular ligament ulna shafts. Ectopic ossification was noted in 15 elbows but varied in its position and size. In one child, ectopic ossification almost completely surrounded the radial head, blocking rotation. by passing the tendon strip round the medial side Proximal migration of the radius was noted in 2 of the radial neck and back through a hole drilled children, both of whom showed restriction of wrist in the proximal ulna. The tendon is then sutured to itself. movement due to distal radioulnar subluxation. To take the strain off the triceps sling, the radial head is held in reduction by a longitudinal transSurgical Reconstruction At the Hospital for Sick Children, Great Ormond capitellar Kirschner wire with the elbow in 900 Street, eight children with unilateral radial head flexion. A longitudinal wire is preferred to obdislocation have been reviewed after late surgical liquely placed wires as the latter increase the risk of reduction of the radial head and reconstruction of ectopic ossification. the annular ligament. Of the 8 children, 4 had Where the ulna is deformed, a corrective osteunrecognized Monteggia lesions, one with varus otomy is necessary to allow adequate reduction of deformity of the proximal third of ulna indicating the radius. This was necessary in one case and the malunion, while 3 had isolated dislocations of the ulna was fixed with a plate (Fig 4). radial head. Surgery was indicated by increasing Postoperatively, the arm has been supported by deformity and limited movements. The ages of the a full arm plaster cast for four weeks after which children ranged from 3 to 8 years and the time the Kirschner wire has been removed. The elbows lapse from injury to operation was an average of have been mobilized routinely six weeks after eighteen months. surgery. The elbow was explored through a posterolateral incision as described by Boyd (1940) with the Results The results of surgical reduction of the radial head patient prone, the arm free and elbow flexed. After opening the elbow joint, the radius was and reconstruction of the annular ligament have found to be firmly adherent to the anterior joint given consistent improvement in elbow function. capsule. Mobilization was carried out by posterior Follow up averaged four years with a range from pressure on the radial head to divide adhesions. eighteen months to eighteen years. Range of flexLigamentous remnants and infolded capsule block- ion in particular has been increased, allowing the ing reduction required excision. Once adequate child to get hand to face where this was previously reduction of the radial head could be achieved, not possible. Improvement in rotation has not reconstruction of the annular ligament was under- been so consistent. taken. Of 8 patients, 2 had free tendon fixation and Correction gave full supination in 7 children but 6 had triceps sling reconstruction of the annular pronation has been full in only 4. Restricted ligament. postoperative pronation corresponded to preoperA strip of triceps tendon is mobilized from the ative limitation of rotation, and has not been lateral border of the main tendon and then by diminished by surgery. In spite of extensive soft tissue release, paraperiosteal stripping, mobilized distally on the lateral aspect of the ulna (Fig 3). This differs from articular ossification has not been a feature followthe technique described by Bell Tawse (1965), who ing surgery and over the long term the radial head used a central strip of triceps. A sling is constructed has continued normal development.
Section of Orthopadics
623
Fig 4 Postoperative radiograph of elbow of 6-year-old child after reduction of the radial head and reconstruction of the annular ligament. A transcapitellar Kirschner wire holds reduction and the ulnar osteotomy wasfixed using a plate
Discussion Established dislocation of the radial head in children may pass unnoticed for many months and later development of the elbow attracts little concern because children apparently have only minor disability. Parents are often advised that no treatment should be undertaken but that if problems occur later, they can be corrected by excision of the radial head at maturity. Review of these children
shows that while established radial dislocation may elicit minor subjective restrictions, mechanical derangements of the growing elbow develop with time, causing disability, and when deformity has been allowed to persist the results of radial head excision are not good. With time, the untreated radial head becomes more adherent to the capsule. Growth deformity impairs elbow movement and subsequent realignment becomes increasingly difficult. When traumatic dislocation is recognized early and the interval from injury is short, it is feasible to reduce the radius and repair the annular ligament with good results. Blount (1954) advised that after a delay of more than three months no attempt should be made to reduce the dislocation. This review indicates that the dislocated radial head requires reduction and adequate stabilization. Late exploration of the proximal radioulnar joint after injury often shows gross disruption of the annular ligament and direct repair is not practicable. In this situation an attempt has to be made to refashion the annular ligament using transplanted fascia or tendon. Watson-Jones (1955) advised that free tendon graft be taken from the palmaris longus or fascia lata, and used in reconstruction.
Bell Tawse (1965) reported results of annular ligament reconstruction using a strip of triceps tendon. He described correction following malunited Monteggia lesions in 5 children, with good results. This review shows that a lateral strip of triceps tendon is most suitable for reconstruction of the annular ligament and reduction held with Kirschner wire fixation for a short period postoperatively. Adequate reduction can be difficult but may be facilitated by ulnar osteotomy. Radial osteotomy is to be avoided as adhesions to the radius are likely to severely restrict subsequent forearm rotation. Summary Problems of unilateral isolated radial head dislocation have been reviewed in 28 children. A significant number indicated failure of recognition of the dislocation after injury. Disability due to increasing deformity and instability was consistently noted and indicated surgical reduction. Late reduction required reconstruction of the annular ligament. A modified method of reconstruction using a strip of triceps tendon is described. Good results are recorded in a small number of children in whom this was carried out. REFERENCES Almquist E E, Gordon L H & Blue A I (1969) Journal of Bone and Joint Surgery 51A, 1118 BeDl Tawse A J S (1965) Journal of Bone and Joint Surgery 47B, 718 Blount N P (1954) Fractures in Children, 1st edn. Williams & Wilkins, Baltimore; p 57
624
Proc. roy. Soc. Med. Volume 70 September 1977
Boyd H B (1940) Surgery, Gynacology and Obstetrics 71, 86 Caravias D E (1957) Journal of Bone and Joint Surgery 39B, 86 Cockshutt W P & Omolulu A (1958) Journal of Bone and Joint Surgery 40B, 483 Mcfarland B (1936) British Journal of Surgery 24, 41 Magee R K (1947) Lancet i, 519 Schubert J J (1965) Journal of Bone and Joint Surgery 47B, 1019 Smith E E (1949) Ohio State Medical Journal 45, 1080 Watson-Jones R (1955) Fractures and Joint Injuries, 4th edn. Livingstone, Edinburgh & London; 2, 579 White J R A (1943) British Journal of Surgery 30, 377
Mr David Jones (Orthopawdic Department, (Norfolk & Norwich Hospital,
Norwich, Norfolk)1 Transcondylar Fractures of the Humerus in Children: Definition of an Acceptable Reduction Most surgeons treat displaced supracondylar fractures of the humerus in children by manipulative reduction followed by the application of a sling or plaster with the elbow as flexed as possible, steering a course between slipping of the fracture and neurovascular complications produced or aggravated by flexion. If the reduction slips, it is often a difficult decision whether to accept the position, remanipulate, or institute another method of treatment. Most series of fractures treated in sling or plaster alone show significant numbers of unsatisfactory results (Bromberger 1973, Mitchell & Adams 1961, Sandeg'ard 1943, Wade & Batdorf 1961). Also, from the limited literature available, late surgical correction of deformity is accompanied by a high complication rate (Rang 1974, Sweeney 1975). Adequate initial reduction is advised. However, there is not general agreement on what is and what is not adequate. Baumann (1929) and Sandeg'ard (1943) quantified varus and valgus angulation radiographically, and correlated this with subsequent clinical deformity. Dodge (1972) used similar measurements in treating a series of patients in Dunlop's traction. However, these and other authors (Dunlop 1939, Gruber & Hudson 1964, Madsen 1955) considered that displacement or anterior and posterior angulation of the distal fragment were also unacceptable, but they do not 1 Requests for reprints to: St Bartholomew's Hospital, London EC1.
elaborate on this. Mann (1963), in a small series of 23 cases, showed that pure displacement of the distal fragment was compatible with a good result. He suggested that small amounts of angular deformity were also acceptable, but did not quantify this. It is well known that there is a good capacity for remoulding after displaced fractures. For instance, Attenborough (1953) presented 4 cases in which remoulding had occurred and in whom good function was obtained. However, 3 of the 4 cases had an obvious cubitus varus. There is general agreement that this deformity does not mould out with time (Flynn et al. 1974, King & Secor 1951). It is known that some fractures do unexpectedly well, and others unexpectedly badly with regard to subsequent deformity. The aim- of this study is to determine what is an acceptable reduction, and thus minimize unexpected results. Clinical material The notes and X-rays of 70 patients admitted for treatment of supracondylar fractures during a three-year period (197141,974) were examined; 15 were excluded as not being transcondylar fractures (Fig 1). The term transcondylar fracture is used here because it is not assumed that fractures occurring above or below this common site are subject to the conclusions drawn from the study. Of the remaining 55 children, 47 (85 %) attended for review. At injury they were aged between 18 months and 13 years (mean 7 years) with follow up taking place 6 months to 3 years (mean 15 months) later. The children were treated as shown in Table 1. Table I Method of treatment of transcondylar fractures (1971-1974)
Method of treatment Manipulation Plaster - no manipulation 7 Plaster - open reduction Operation - per cutaneous K wire I Dunlop's traction (prospective group)
No. of cases 25 8 6
In each case the initial notes and X-rays were studied, and the following radiographic measurements made: anterior or posterior angulation (Fig 2); anterior or posterior displacement; medial or lateral displacement; the Baumann angle (Fig 3). These measurements were repeated on all available X-rays taken during treatment, and compared with the clinical and radiographic result at the time of review.
The Baumann angle This was first described in 1929. It is the angle between a line drawn perpendicularly to the axis of the humerus and a line drawn along the lower
Proc. roy. Soc. Med. Volume 70 September 1977
Section of Orthopadics President G C Lloyd Roberts Mch
Meeting I February 1977
The Elbow Joint Mr T M BucknilH (East Birmingham Hospital, Bordesley Green East, Birmingham B9 SST)
Anterior Dislocation of the Radial Head in Children
Established dislocation of the head of the radius is an uncommon but important feature of elbow and forearm injuries in children. Young children adapt so easily to forearm disability that despite retricted movements, subjective symptoms are often minimal. Parental concern over a child with a dislocated radial head may not be aroused until growth increases deformity and disability. Similarly, a forearm anomaly may remain unnoticed until a minor elbow injury draws attentionto a long established deformity, and with pain, swelling and an abnormal X-ray, the distinction between congenital and traumatic elbow lesions is easily confused. The susceptibility of the radial head to subluxation and less commonly to dislocation in young children is well recognized, but generally there has been a cautious and guarded approach to surgical correction of the displaced radial head. Orthop2dic literature has focused intermittent interest over the years in the isolated radial head dislocation but case numbers have been few, and impressions often inconclusive. Mostly these reports have described radial head dislocations presumed to be of congenital origin more from lack of any known trauma than from specific clinical features. The distortion of elbow anatomy associated with a congenital anomaly must certainly influence any attempt at reduction or reconstruction of an elbow and the distinction between congenital and traumatic lesions is of considerable importance. Several well recognized syndromes and skeletal anomalies in children include radial head dis-
Fig I Traumatic radial head dislocation of radial head in a child of 3 years showing para-articular ossification
Section of Orthopadics
location as one of their features. Almquist et al. (1969) reviewed congenital radial head problems and listed ten primary conditions in which radial head dislocation had been previously noted and added four further conditions. Generally, congenital head dislocations seen with multiple anomalies are typically posterior and bilateral. In their review of 18 children with congenital dislocations Almquist et al. (1969) reported only 4 isolated radial dislocations and these were all posterior. The classic description of features of the congenitally dislocated radial head was made by Mcfarland in 1936. He reported 11 cases of anterior radial dislocation and emphasized radiological features that he considered to be specific to congenital lesions. These referred mainly to an elliptical deformed radial head and a dysplastic capitellum. Concavity of the posterior border of the proximal ulna and para-articular ossification were additional features (Fig 1). Since Mcfarland's original description, further cases of isolated dislocations of the radial head have been reported at intervals.
621
White (1943) added cases and Magee (1947) described a bilateral case. Smith (1949) reviewed 5 cases and Caravias (1957) reviewed 3. In 1965 Schubert described a case of radial head dislocation in a neonate, which he was able to reduce and maintain adequately stable. Cockshutt & Omolulu (1958) reported a neonate with bilateral recurrent anterior dislocation of the radial heads, indicating marked radioulnar instability.
Clinical Material. In this review, 28 children with isolated unilateral radial head dislocation have been assessed. Many have shown features described by Mcfarland as typically congenital in origin but only 5 of these gave no history of trauma, and their deformities were indistinguishable from the others. The time lapse from injury to presentation varied from three months to eleven years with an average of three years. Often the injury had been previously diagnosed as a contusion or sprain and the arm supported in a sling until comfortable. Over one-third of those with a history of injury had undergone clinical and radiographic examination
Fig 2 Anterior radial head dislocation with ulnar bowing three years after injury
622
Proc. roy. Soc. Med. Volume 70 September 1977
at the time of injury, however, the lesion had escaped detection. Some months later, when the elbow remained deformed and movements restricted, the parents sought further advice. Average age at injury was 7j years. Accurate assessment of the original injuries in this review was not possible. However, 11 of the 28 showed angulation of the proximal ulna indicating malunion following a Monteggia lesion. Fig 2 shows anterior radial head dislocation with ulnar bowing. Consistently, the affected elbows showed some restriction of movements, most commonly in flexion and pronation. An increased carrying angle was noted in 12 of the elbows, with valgus instability in 11 of these. Varus angulation was noted in 6 elbows and Fig 3 Drawing showing a strip of tendon from the lateral corresponded to varus malunion of the proximal border of triceps used to reconstruct the annular ligament ulna shafts. Ectopic ossification was noted in 15 elbows but varied in its position and size. In one child, ectopic ossification almost completely surrounded the radial head, blocking rotation. by passing the tendon strip round the medial side Proximal migration of the radius was noted in 2 of the radial neck and back through a hole drilled children, both of whom showed restriction of wrist in the proximal ulna. The tendon is then sutured to itself. movement due to distal radioulnar subluxation. To take the strain off the triceps sling, the radial head is held in reduction by a longitudinal transSurgical Reconstruction At the Hospital for Sick Children, Great Ormond capitellar Kirschner wire with the elbow in 900 Street, eight children with unilateral radial head flexion. A longitudinal wire is preferred to obdislocation have been reviewed after late surgical liquely placed wires as the latter increase the risk of reduction of the radial head and reconstruction of ectopic ossification. the annular ligament. Of the 8 children, 4 had Where the ulna is deformed, a corrective osteunrecognized Monteggia lesions, one with varus otomy is necessary to allow adequate reduction of deformity of the proximal third of ulna indicating the radius. This was necessary in one case and the malunion, while 3 had isolated dislocations of the ulna was fixed with a plate (Fig 4). radial head. Surgery was indicated by increasing Postoperatively, the arm has been supported by deformity and limited movements. The ages of the a full arm plaster cast for four weeks after which children ranged from 3 to 8 years and the time the Kirschner wire has been removed. The elbows lapse from injury to operation was an average of have been mobilized routinely six weeks after eighteen months. surgery. The elbow was explored through a posterolateral incision as described by Boyd (1940) with the Results The results of surgical reduction of the radial head patient prone, the arm free and elbow flexed. After opening the elbow joint, the radius was and reconstruction of the annular ligament have found to be firmly adherent to the anterior joint given consistent improvement in elbow function. capsule. Mobilization was carried out by posterior Follow up averaged four years with a range from pressure on the radial head to divide adhesions. eighteen months to eighteen years. Range of flexLigamentous remnants and infolded capsule block- ion in particular has been increased, allowing the ing reduction required excision. Once adequate child to get hand to face where this was previously reduction of the radial head could be achieved, not possible. Improvement in rotation has not reconstruction of the annular ligament was under- been so consistent. taken. Of 8 patients, 2 had free tendon fixation and Correction gave full supination in 7 children but 6 had triceps sling reconstruction of the annular pronation has been full in only 4. Restricted ligament. postoperative pronation corresponded to preoperA strip of triceps tendon is mobilized from the ative limitation of rotation, and has not been lateral border of the main tendon and then by diminished by surgery. In spite of extensive soft tissue release, paraperiosteal stripping, mobilized distally on the lateral aspect of the ulna (Fig 3). This differs from articular ossification has not been a feature followthe technique described by Bell Tawse (1965), who ing surgery and over the long term the radial head used a central strip of triceps. A sling is constructed has continued normal development.
Section of Orthopadics
623
Fig 4 Postoperative radiograph of elbow of 6-year-old child after reduction of the radial head and reconstruction of the annular ligament. A transcapitellar Kirschner wire holds reduction and the ulnar osteotomy wasfixed using a plate
Discussion Established dislocation of the radial head in children may pass unnoticed for many months and later development of the elbow attracts little concern because children apparently have only minor disability. Parents are often advised that no treatment should be undertaken but that if problems occur later, they can be corrected by excision of the radial head at maturity. Review of these children
shows that while established radial dislocation may elicit minor subjective restrictions, mechanical derangements of the growing elbow develop with time, causing disability, and when deformity has been allowed to persist the results of radial head excision are not good. With time, the untreated radial head becomes more adherent to the capsule. Growth deformity impairs elbow movement and subsequent realignment becomes increasingly difficult. When traumatic dislocation is recognized early and the interval from injury is short, it is feasible to reduce the radius and repair the annular ligament with good results. Blount (1954) advised that after a delay of more than three months no attempt should be made to reduce the dislocation. This review indicates that the dislocated radial head requires reduction and adequate stabilization. Late exploration of the proximal radioulnar joint after injury often shows gross disruption of the annular ligament and direct repair is not practicable. In this situation an attempt has to be made to refashion the annular ligament using transplanted fascia or tendon. Watson-Jones (1955) advised that free tendon graft be taken from the palmaris longus or fascia lata, and used in reconstruction.
Bell Tawse (1965) reported results of annular ligament reconstruction using a strip of triceps tendon. He described correction following malunited Monteggia lesions in 5 children, with good results. This review shows that a lateral strip of triceps tendon is most suitable for reconstruction of the annular ligament and reduction held with Kirschner wire fixation for a short period postoperatively. Adequate reduction can be difficult but may be facilitated by ulnar osteotomy. Radial osteotomy is to be avoided as adhesions to the radius are likely to severely restrict subsequent forearm rotation. Summary Problems of unilateral isolated radial head dislocation have been reviewed in 28 children. A significant number indicated failure of recognition of the dislocation after injury. Disability due to increasing deformity and instability was consistently noted and indicated surgical reduction. Late reduction required reconstruction of the annular ligament. A modified method of reconstruction using a strip of triceps tendon is described. Good results are recorded in a small number of children in whom this was carried out. REFERENCES Almquist E E, Gordon L H & Blue A I (1969) Journal of Bone and Joint Surgery 51A, 1118 BeDl Tawse A J S (1965) Journal of Bone and Joint Surgery 47B, 718 Blount N P (1954) Fractures in Children, 1st edn. Williams & Wilkins, Baltimore; p 57
624
Proc. roy. Soc. Med. Volume 70 September 1977
Boyd H B (1940) Surgery, Gynacology and Obstetrics 71, 86 Caravias D E (1957) Journal of Bone and Joint Surgery 39B, 86 Cockshutt W P & Omolulu A (1958) Journal of Bone and Joint Surgery 40B, 483 Mcfarland B (1936) British Journal of Surgery 24, 41 Magee R K (1947) Lancet i, 519 Schubert J J (1965) Journal of Bone and Joint Surgery 47B, 1019 Smith E E (1949) Ohio State Medical Journal 45, 1080 Watson-Jones R (1955) Fractures and Joint Injuries, 4th edn. Livingstone, Edinburgh & London; 2, 579 White J R A (1943) British Journal of Surgery 30, 377
Mr David Jones (Orthopawdic Department, (Norfolk & Norwich Hospital,
Norwich, Norfolk)1 Transcondylar Fractures of the Humerus in Children: Definition of an Acceptable Reduction Most surgeons treat displaced supracondylar fractures of the humerus in children by manipulative reduction followed by the application of a sling or plaster with the elbow as flexed as possible, steering a course between slipping of the fracture and neurovascular complications produced or aggravated by flexion. If the reduction slips, it is often a difficult decision whether to accept the position, remanipulate, or institute another method of treatment. Most series of fractures treated in sling or plaster alone show significant numbers of unsatisfactory results (Bromberger 1973, Mitchell & Adams 1961, Sandeg'ard 1943, Wade & Batdorf 1961). Also, from the limited literature available, late surgical correction of deformity is accompanied by a high complication rate (Rang 1974, Sweeney 1975). Adequate initial reduction is advised. However, there is not general agreement on what is and what is not adequate. Baumann (1929) and Sandeg'ard (1943) quantified varus and valgus angulation radiographically, and correlated this with subsequent clinical deformity. Dodge (1972) used similar measurements in treating a series of patients in Dunlop's traction. However, these and other authors (Dunlop 1939, Gruber & Hudson 1964, Madsen 1955) considered that displacement or anterior and posterior angulation of the distal fragment were also unacceptable, but they do not 1 Requests for reprints to: St Bartholomew's Hospital, London EC1.
elaborate on this. Mann (1963), in a small series of 23 cases, showed that pure displacement of the distal fragment was compatible with a good result. He suggested that small amounts of angular deformity were also acceptable, but did not quantify this. It is well known that there is a good capacity for remoulding after displaced fractures. For instance, Attenborough (1953) presented 4 cases in which remoulding had occurred and in whom good function was obtained. However, 3 of the 4 cases had an obvious cubitus varus. There is general agreement that this deformity does not mould out with time (Flynn et al. 1974, King & Secor 1951). It is known that some fractures do unexpectedly well, and others unexpectedly badly with regard to subsequent deformity. The aim- of this study is to determine what is an acceptable reduction, and thus minimize unexpected results. Clinical material The notes and X-rays of 70 patients admitted for treatment of supracondylar fractures during a three-year period (197141,974) were examined; 15 were excluded as not being transcondylar fractures (Fig 1). The term transcondylar fracture is used here because it is not assumed that fractures occurring above or below this common site are subject to the conclusions drawn from the study. Of the remaining 55 children, 47 (85 %) attended for review. At injury they were aged between 18 months and 13 years (mean 7 years) with follow up taking place 6 months to 3 years (mean 15 months) later. The children were treated as shown in Table 1. Table I Method of treatment of transcondylar fractures (1971-1974)
Method of treatment Manipulation Plaster - no manipulation 7 Plaster - open reduction Operation - per cutaneous K wire I Dunlop's traction (prospective group)
No. of cases 25 8 6
In each case the initial notes and X-rays were studied, and the following radiographic measurements made: anterior or posterior angulation (Fig 2); anterior or posterior displacement; medial or lateral displacement; the Baumann angle (Fig 3). These measurements were repeated on all available X-rays taken during treatment, and compared with the clinical and radiographic result at the time of review.
The Baumann angle This was first described in 1929. It is the angle between a line drawn perpendicularly to the axis of the humerus and a line drawn along the lower
