Malunion remains one of the most commonly observed complications of
a fracture of the distal
part1-3.
The deformity may be extra-articular, intra-articular, or a combination of the
two Mof the radius4.
While operative treatment of extra-articular malunions has been widely
studied3-8,
few reports describe the results of osteotomy for symptomatic intra-articular
deformity4,9,10,
even though articular incongruity is consistently identified as an important
predictor of an adverse functional
outcome11-14.
The relative reluctance to address intra-articular malunion may be due to
several factors, including limited surgical access, difficulty achieving
secure fixation of small articular fracture fragments, concern regarding the
ability to recreate the articular fracture without causing additional
articular damage, and concern about compromising the blood supply to the
osteotomized fragment, which can lead to osteonecrosis with resultant
collapse, failure to heal, and arthrosis.
Improvements in imaging, especially three-dimensional reconstructions of
computed tomography scans, as well as the availability of low-profile implants
for fixation of small articular fragments have helped to stimulate interest in
the surgical correction of intra-articular malunions of the distal part of the
radius. The purpose of this paper was to present the experience of surgeons
with intra-articular osteotomies for these injuries at four institutions, with
an emphasis on the indications, techniques, and outcomes.
Inclusion and Exclusion Criteria
A protocol for the retrospective review of medical records and
radiographs, and selective invitation to return for additional follow-up with
informed consent, was approved by our institutional review boards.
The criteria for inclusion in this study were (1) treatment with an
intra-articular osteotomy of the distal part of the radius during the
eight-year period between 1993 and 2001 at one of four institutions, (2)
skeletal maturity, and (3) treatment with the osteotomy three months or more
after the original injury. Patients who had been followed for less than two
years were excluded. Twenty-six patients satisfied the inclusion criteria, and
twenty-three had adequate follow-up. One patient had died, and two could not
be contacted. The remaining twenty-three patients were evaluated by the
treating surgeon at an average of thirty-eight months (range, twenty-four to
102 months) after the osteotomy. The study was approved by our human research
committee.
Patients
There were sixteen men and seven women with an average age of thirty-seven
years (range, eighteen to sixty-seven years) (see Appendix). Thirteen patients
had involvement of the right, dominant arm, and ten had involvement of the
left, nondominant arm. According to the classification system of
Fernandez15, the
original injury was a shearing-type fracture (type 2) in twelve patients, a
compression-type fracture (type 3) in ten patients, and a combined high-energy
fracture (type 5) in one patient. According to the Comprehensive
Classification of Fractures of Long
Bones16
system, there were two B1.1 fractures, one B1.2 fracture, one B1.3 fracture,
six B3.2 fractures, two B3.3 fractures, one C1.1 fracture, six C2.1 fractures,
one C2.3 fracture, one C3.1 fracture, and two C3.2 fractures.
The initial treatment of the radial fracture was manipulative reduction and
cast immobilization for fourteen patients and operative treatment for nine
patients. The operative methods included Kirschner wire fixation and cast
immobilization for seven patients, open reduction and plate-and-screw fixation
for one patient, and external fixation for one patient. The interval from the
initial injury to the intra-articular osteotomy averaged six months (range,
three to fourteen months). One patient presented with a chronic regional pain
syndrome, and one had severe arthritis of the distal radioulnar joint.
Prior to the operation, the patients had, on average, 37° (range,
5° to 70°) of wrist extension, 44° (range, 0° to 80°) of
wrist flexion, 64° (range, 10° to 90°) of forearm pronation,
57° (range, 5° to 90°) of forearm supination, 14° (range,
0° to 30°) of radial deviation, and 17° (range, 0° to 45°)
of ulnar deviation. Preoperative grip strength averaged 50% (range, 17% to
98%) of that on the contralateral side.
Indications for Osteotomy
The indications for the osteotomy included (1) articular incongruity in the
coronal plane with subluxation of the radiocarpal joint in fourteen patients
(ten with volar and four with dorsal subluxation) and (2) articular
incongruity of =2 mm (maximum step-off or gap), as measured on the
posteroanterior radiograph, in seventeen patients (eight of whom also had
radiocarpal subluxation). Six patients also had extra-articular deformity: two
had volar angulation, two had dorsal angulation, and two had shortening of the
radius.
All of the radiographic measurements of the deformity before the
osteotomies were made according to standard
descriptions17. The
average radiographic parameters included ulnar inclination of 23° (range,
5° to 36°), volar angulation of the distal radial articular surface on
the lateral radiograph of 3° (range, 40° of dorsal angulation to
31° of volar angulation), 3 mm of ulna-positive ulnar variance (range, 9
mm of ulna-positive to 2 mm of ulna-negative ulnar variance), and a maximum
intra-articular step-off or gap of 4 mm (range, 2 to 15 mm). There were
radiographic signs of arthrosis, all Grade 1 according to the system of Knirk
and Jupiter13,
prior to the osteotomy in six patients.
Operative Technique
The general operative tactic was to recreate the fracture lines with an
osteotome, resect bone until the articular portion of the fracture could be
accurately reduced, secure the fracture fragments with internal fixation, and
then apply bone graft to any remaining osseous defects. The operative approach
was dorsal in thirteen patients, volar in nine patients, and both dorsal and
volar in one patient. A volar exposure was used in the ten patients who had
volar subluxation of the carpus consequent to a malaligned volar articular
fragment. (A combined dorsal and volar exposure was used in one of those
patients.) Only a dorsal exposure was used in the remaining twelve
patients.
Through the volar approach, the volar radiocarpal ligaments were left
intact. When a patient had a malunited volar shearing fracture, the joint was
visualized through the fracture (Figs. 1-A
through 1-F). Through the dorsal exposure, the articular surface
was monitored through a dorsal capsulotomy and soft-tissue attachments were
maintained either with volar or radial soft tissues or with the radioulnar
joint capsule (Figs. 2-A through
2-H). The articular reduction was also carefully monitored with
image intensification (Fig.
2-H).
The osteotomy was secured with screws alone in seven patients, Kirschner
wires alone in two patients, and a plate and screws in fourteen patients (with
the addition of screws independent of the plate in four patients). The plates
included four dorsal pi-plates, three volar pi-plates, five 3.5-mm T-shaped
plates, and two 2.0-mm plates in two patients (all implants manufactured by
Synthes, Paoli, Pennsylvania). Autogenous bone graft was applied in seventeen
patients. It was obtained from the iliac crest in fourteen patients, the
proximal part of the ulna in two patients, and the radius in one patient. The
one patient with severe arthrosis of the distal radioulnar joint had
concomitant fusion of the distal radioulnar joint and intentional creation of
a distal ulnar pseudarthrosis (the Sauve-Kapandji procedure).
Postoperative Management
All patients had a light volar plaster splint incorporated in the
postoperative dressing until suture removal. A removable volar plastic splint
was then used to support the wrist until six weeks after the surgery.
Functional use of the arm for light tasks and mobilization of the digits and
forearm were encouraged immediately after the surgery. It was stressed that
the patients should avoid strenuous manual labor and sports activity for at
least three months postoperatively and until solid union of the fracture was
confirmed on radiographs.
Complications and Subsequent Operations
One patient with dorsal 2.0-mm plates had a rupture of the extensor
pollicis longus tendon, which was treated with a transfer of the extensor
indicis proprius. Three patients had additional surgery: one had a
Sauve-Kapandji procedure to address arthrosis of the distal radioulnar joint,
one had a radioscapholunate fusion and hemiresection arthroplasty of the
distal radioulnar joint to address arthrosis of the radiocarpal and distal
radioulnar joints, and one had an ulnar shortening osteotomy.
Implants were removed at a subsequent operation, at an average of seven
months (range, two to fifteen months) after the first operation in seven
patients. Dorsal implants were removed routinely in one center, whereas they
were removed only in the presence of tendon irritation in the others. None of
the volar implants were removed.
Evaluation
The final evaluation was performed by the treating surgeon with use of the
Fernandez point-score system for distal radial
osteotomy6, the
Gartland and Werley
system18, and a
modification of the Green and O'Brien rating
system19.
According to the Fernandez point-score
system6, patients
rate their pain as none, mild (with activities of daily living), or severe
(pain at rest). The grip strength was measured with a Jamar dynamometer (the
average of three attempts) and was recorded as a percentage of the strength of
the uninjured hand. According to the point-score system, a total score of 18,
19, or 20 points is excellent; 15, 16, or 17 points, good; 12, 13, or 14
points, fair; and =11 points, poor.
The system of Gartland and
Werley18 is a
demerit point system accounting for deformity, subjective evaluation, motion,
pain, arthritis, and nerve and hand complications. A score of 0, 1, or 2
points indicates an excellent result; 3 to 8 points, good; 9 to 20 points,
fair; and =21 points, poor.
The Mayo modification of the Green and O'Brien
system19 is very
strict and consistently produces lower categorical ratings. This system
evaluates pain, functional status, range of motion, and grip strength,
awarding a maximum of 25 points to each. To receive the highest score in each
category, the patient must essentially have a normal upper extremity (no pain,
100% motion, 100% grip strength, and a return to regular employment). The
categorical ratings are also strict, with 90 to 100 points indicating an
excellent result; 80 to 89 points, good; 65 to 79 points, fair; and <65
points, poor.
Radiographic signs of arthrosis were graded according to the system of
Knirk and
Jupiter13. Changes
in the range of motion and radiographic parameters between the preoperative
and final follow-up evaluations were assessed with use of a paired t test,
with a p value of <0.05 indicating significance.
The patients were evaluated at an average of thirty-eight months
(range, twenty-four to 102 months) after the injury. All of the osteotomy
sites had healed without evidence of osteonecrosis. The patient who had been
treated with a subsequent radioscapholunate arthrodesis and hemiresection
arthroplasty of the distal part of the ulna was considered to have had a
failure of the index operation and was excluded from the final analysis.
The final ranges of motion averaged 56° (range, 30° to 81°) of
wrist extension, 56° (range, 30° to 85°) of wrist flexion, 80°
(range, 30° to 90°) of pronation, 81° (range, 50° to 90°)
of supination, 22° (range, 5° to 40°) of radial deviation, and
33° (range, 15° to 55°) of ulnar deviation. Final grip strength
averaged 85% (range, 64% to 124%) of that of the contralateral hand. All of
these improvements were significant (p < 0.05).
The final radiographic parameters averaged 23° (range, 15° to
36°) of ulnar inclination, 6° of volar angulation (range, 14° of
volar angulation to 10° of dorsal angulation) of the distal radial
articular surface on the lateral radiograph, neutral ulnar variance (range, 6
mm of ulna-negative to 4 mm of ulna-positive ulnar variance), and 0.4 mm
(range, 0 to 3 mm) of articular incongruity, with six patients having
incongruity of =1 mm. The improvements in ulnar inclination (as seen on the
posteroanterior radiograph) and radial inclination (as seen on the lateral
radiograph) were not significant (p > 0.05), whereas the improvements in
ulnar variance and articular incongruity were significant (p < 0.05).
Ten patients had radiographic signs of radiocarpal arthrosis, which was
rated as type 2 in two of them and type 1 in eight according to the system of
Knirk and
Jupiter13.
The average score according to the Fernandez
system6 was 16
points (range, 12 to 20 points), with six excellent, thirteen good, and three
fair results. According to the system of Gartland and
Werley18, the
average demerit score was 5 points (range, 2 to 15 points), with seven
excellent, twelve good, and three fair results. According to the modification
of the system of Green and
O'Brien19, the
average score was 76 points (range, 50 to 95 points), with two excellent,
eight good, and eleven fair results and one poor result. The patient who had a
subsequent radioscapholunate fusion was considered to have a poor result
according to all of the rating systems.
The data reported here demonstrate that intra-articular osteotomy of
the distal part of the radius can be safe and effective. No patient had
evidence of nonunion or osteonecrosis. In our series, in which we used strict
selection criteria, only two patients required a salvage operation after the
index procedure: one needed it because of radiocarpal arthritis, and one,
because of distal radioulnar arthritis. The fact that almost 60% of the
results were fair or poor according to the modified Green and O'Brien rating
scale19 reflects
the strictness of that system and indicates that osteotomy for malunited
articular fractures of the distal part of the radius rarely restores normal or
nearly normal wrist function. However, the paucity of fair or poor results
according to the
Fernandez6 and
Gartland and
Werley18 rating
systems emphasizes that useful wrist function can be restored with this
reconstructive procedure.
The demonstration by Knirk and
Jupiter13 of a
strong influence of intra-articular malunion on the radiographic and
functional outcomes of fractures of the distal part of the radius has been
corroborated by other
investigators11,12,14.
Acute realignment of the joint surface to within 2 mm of normal is associated
with relatively good results. It can be argued that intra-articular
incongruity is much more likely than extra-articular malunion to compromise
wrist function.
It is not our intention to encourage surgeons to operate or reoperate on
all fractures of the distal part of the radius, including those with even
slight residual articular incongruity. Given the risks of operative
intervention, we used relatively strict indications for surgery. The articular
malunion was associated with subluxation of the radiocarpal joint in fourteen
(61%) of the twenty-three patients and with extra-articular malunion in six
(26%). We operated on symptomatic articular malunions and on malunions with a
high likelihood of rapid degeneration of the articular surface. Patients with
a slight articular malunion in a relatively nonarticular area (for example,
between the scaphoid and lunate facets of the distal part of the radius) would
probably not benefit from an osteotomy. Contraindications include established,
advanced arthrosis; low-demand and infirm patients; and patients who are older
than seventy years of age with few symptoms and adequate wrist function.
The relatively short average interval of six months between the injury and
the osteotomy demonstrates that the earlier that the osteotomy is performed,
the easier it is to accomplish and that, when radiographic predictors of
arthrosis and diminished wrist function are identified, there is no point in
delaying the
osteotomy4. This is
particularly true for an intra-articular osteotomy, as advanced arthrosis will
develop within the first year following many severe articular malunions,
making osteotomy unfeasible and salvage procedures
necessary1.
The results of corrective osteotomy for treatment of intra-articular
malunion of the distal part of the radius compare favorably with those
reported after osteotomies for extra-articular
malunion3-8,20.
The procedure seems to be useful for improving and prolonging the wrist
function of healthy, active patients. However, it cannot restore a normal
wrist, some patients will require salvage because of arthrosis of the
radiocarpal or distal radioulnar joint, and some patients will have
implant-related complications such as tendon irritation and tendon
rupture.
A table presenting the clinical and radiographic details for all patients
is available with the electronic versions of this article, on our web site at
(go to
the article citation and click on "Supplementary Material") and on
our quarterly CD-ROM (call our subscription department, at 781-449-9780, to
order the CD-ROM). ?
In support of their research or preparation of this manuscript, one or more
of the authors received grants or outside funding from the AO Foundation. None
of the authors received payments or other benefits or a commitment or
agreement to provide such benefits from a commercial entity. No commercial
entity paid or directed, or agreed to pay or direct, any benefits to any
research fund, foundation, educational institution, or other charitable or
nonprofit organization with which the authors are affiliated or
associated.