Patients with nonunion of a fracture of the lateral humeral condyle
may later present with pain, instability, or progressive cubitus
valgus deformity with tardy ulnar nerve palsy
1
. The treatment of an established nonunion of the lateral humeral
condyle remains controversial. The main reasons that some authors
have not recommended operative intervention are the risks of decreasing
the range of motion of the elbow and of jeopardizing the vascularity
of the fragment
2-6
. Recently, however, some authors have reported satisfactory results
with operative treatment
7-11
. It is occasionally difficult to decide whether osteosynthesis should
be performed in an adult.
In the current study, we evaluated patients with long-standing established
nonunion of the lateral humeral condyle in order to clarify the
long-term clinical outcome of this condition and to identify factors
contributing to the results.
From 1985 to 1998, we evaluated thirty-seven elbows in thirty-six
patients with nonunion of the lateral humeral condyle at Hirosaki
University Hospital and affiliated hospitals. In order to focus
on the clinical status of patients with long-standing nonunion,
we excluded patients who were less than twenty years of age from
this study. This left nineteen elbows in eighteen patients. All
subjects gave informed consent prior to the study. The symptoms
at presentation were pain after sports or work in seven elbows,
apprehension due to subjective instability in seven, deformity in
two, and ulnar nerve dysfunction in sixteen. One of the patients
(Case 10) consulted our hospital about another, unrelated problem.
In interviews about the condition of the elbow, the patient revealed
that she had mild apprehension when using the elbow at work. Another
patient (Cases 9 and 19), with the bilateral nonunion, had no symptoms
in one elbow. Thus, the elbow nonunions in Cases 10 and 19 were
found by chance.
Fourteen patients were male and four were female. The average
age was 5.4 years (range, three to ten years) at the time of injury
and 42.5 years (range, twenty to seventy-eight years) when the patient
presented with symptoms of the nonunion. Initially, all but one
injury had been treated nonoperatively by a bone-setter. The remaining
fracture was treated with open reduction and osteosynthesis but
still resulted in a nonunion. One patient had a corrective osteotomy
of the humerus because of a valgus deformity and neurolysis of the
ulnar nerve at the age of twelve years. No other patient had additional
treatment prior to presentation to our hospital. The interval from
injury to presentation of the symptoms of the nonunion ranged from
sixteen to seventy-three years, with an average of thirty-seven
years. Clinical evaluation was performed with use of the functional
rating index of Broberg and Morrey
12
and clinical assessment of pain, apprehension, grip strength, range
of motion, deformity, and ability to perform activities of daily
living.
Radiographic Evaluation
Using standard anteroposterior and lateral radiographs, we evaluated
the shape of the articular surface of the trochlea, the radiocapitellar
joint, the ulnar aspect of the capitellum, and the coronoid process.
We were able to use the normal, contralateral side for comparison
in all patients except the one with the bilateral nonunion. We differentiated
between Milch Type-I and Milch Type-II injuries
13
on the basis of the size of the fragment and the location of the fracture
line.
The data in both groups of patients were analyzed with the Mann-Whitney
U test. The correlation coefficient was analyzed with the Spearman
rank correlation test. Differences were considered significant when
the p value was <0.05.
Table I
shows the clinical data for all patients. They were divided into
two distinct groups. Group-1 patients had a small fragment of the
lateral condyle as well as a rounded radial head and a concave capitellum
resulting from a Milch Type-I injury (
Fig. 1
). Group-2 patients had a large fragment of the lateral condyle and
an almost normal radiocapitellar relationship as a result of a Milch
Type-II injury (
Fig. 1
). All cases were clearly seen to fit into either Group 1 or Group
2. Nine elbows were categorized as Group 1 and ten, as Group 2.
Group 1 was composed of seven male and two female patients, and
the average age at presentation with the symptoms of the nonunion
was forty-seven years (range, twenty to seventy-eight years). The
interval from the injury to presentation with the nonunion ranged
from sixteen to seventy-three years, with an average of 41.2 years.
Eight of the nine patients had ulnar nerve dysfunction. Six patients
complained of elbow pain, and five reported apprehension due to
subjective instability.
Group 2 consisted of eight male and two female patients. The average
age at presentation with the symptoms of the nonunion was 38.9 years
(range, twenty-five to seventy-eight years). The interval from injury
to presentation ranged from nineteen to seventy-three years, with
an average of thirty-three years. One patient had pain after sports
and working, two had apprehension due to subjective instability,
and eight had ulnar nerve dysfunction. One patient with bilateral
nonunion of the lateral humeral condyle had no symptoms in the Group-2
elbow but came to our hospital because of pain in the contralateral
(Group-1) elbow.
Range of Motion
Radiographic Findings
In Group 1, the fragment of the lateral condyle was typically small
and displaced laterally, with the radiocapitellar joint space proximal
to the level of the ulnohumeral joint. The radial head was round,
and the radial notch of the ulna and the remaining small capitellar
fragment had become concave to match the shape of the round radial
head. On the anteroposterior radiograph, the articular surface of
the trochlea had a tendency to become flattened sooner following
injury. This flattening was also more pronounced than that seen
in Group 2. Lateral and proximal displacement of the ulna was also noted,
and it tended to increase as the patient grew older.
In Group 2, the width of the lateral condyle fragment typically was
larger than that in Group 1, and the radial head seemed to have
hypertrophied in comparison with the contralateral, normal head.
However, the shape of the radiocapitellar joint remained almost
normal. The radiocapitellar joint space was almost at the level
of, or was distal to, the ulnohumeral joint. On the anteroposterior
radiograph, the articular surface of the trochlea remained nearly
anatomic in shape in younger patients, but it had a tendency to
become more flattened in patients with a longer interval since the
injury. The ulnar aspect of the capitellar fragment and the coronoid
process often were noted to form a false joint space.
Carrying Angle
Clinical Status
Group-1 patients more frequently reported pain and/or apprehension
than did Group-2 patients. Apprehension consisted of a subjective
sense of instability in a valgus direction and often occurred while
the patient leaned on the hand with the elbow extended or while
he or she carried a heavy object. The mechanism of this instability
was thought to be an unstable nonunion site associated with the
valgus deformity of the elbow. Also, the normal osseous stability
of the ulnohumeral joint had been lost in this condition. A significantly
longer interval from the injury to the development of pain was also
observed in Group 1 (p = 0.0249).
The average functional rating index of Broberg and Morrey was
76 points (range, 27 to 95 points) in Group 1 and 93 points (range,
79 to 100 points) in Group 2. The difference was significant (p
= 0.03). There was a significant decrease in the score with an increased
time from the injury (r = -0.475, p = 0.0409).
Illustrative Case Report
Moorhead5 reported on a nonunion of the lateral humeral condyle,
seen seventeen years after injury, that he did not treat because
of the absence of pain and an acceptable range of motion. Smith
6
reported on an eighty-five-year-old woman, an experienced French
horn player, who had a long-standing nonunion and ulnar nerve palsy
as the only symptom. These case reports suggested that some patients
with untreated long-standing nonunion may have only minimal symptoms
or disabilities. There are, however, only a few long-term follow-up
reports on patients with untreated nonunion5,6,14.
In the current study, we divided patients who presented with
a long-standing nonunion of a fracture of the lateral humeral condyle
into two groups that appeared to correlate with the two commonly
seen types of fracture of the lateral condyle. It appears that a
Milch Type-I fracture develops into the type of nonunion seen in
our Group 1. Milch classified a Type-I fracture as one involving
either the lateral aspect of the capitellum laterally or the medial
lip of the trochlea medially. In this type of fracture, the normal
radiocapitellar relationship is lost because of separation of a
portion of the capitellum, which tends to migrate laterally. Milch
Type-II fractures involve either the entire capitellum and the lateral
aspect of the trochlea laterally or the entire trochlea medially.
In this type of fracture, the normal radiocapitellar relationship
is maintained. Therefore, despite their relatively greater initial
instability, Milch Type-II fractures may not result in as much deformity of
the radial head and capitellum, even if nonunion occurs.
We found tardy ulnar nerve palsy to be the major symptom in both
groups. We noted this dysfunction even in patients with a normal
or less-than-normal carrying angle. This may be due to the abnormal
sliding of the ulnar nerve caused by excessive mobility at the nonunion
site or alteration of the normal arc of elbow motion. Tardy ulnar
nerve palsy may not appear until several years after the initial
injury.
In Group 2, pain was rare and the range of motion of the elbow
was not severely limited. In Group 1, pain was more frequent and
the range of motion was more severely limited. In both groups, the
range of motion tended to become more limited with time.
In conclusion, because Group-1 nonunions consistently lead to
pain, instability, loss of function, and tardy ulnar nerve palsy,
they should be treated as soon as possible after injury, preferably
before skeletal maturity.
Note: The authors thank Dr. Jack F. Rocco (Chairman, Orthopaedic
Surgery, Misawa Air Base) for his suggestions and advice during
this investigation.