We retrospectively reviewed the experience of the two senior ones of us (D. L. F. and J. B. J.) at Kantonspital in Aarau, Switzerland, and at Massachusetts General Hospital in Boston, Massachusetts, with regard to corrective osteotomy for the treatment of malunited, volarly angulated fractures of the distal end of the radius in twenty-five consecutive patients from 1986 to 1995. All patients had been managed initially at other institutions and later were referred to us because of a residual deformity.
The indications for the osteotomy were pain or functional limitations rather than the degree of anatomical deformity. The preoperative functional problems included painful or limited supination of the forearm, loss of extension of the wrist due to volar displacement of the distal radial fragment, and loss of grip strength that adversely affected the patient's capacity to return to his or her preinjury occupation. The criteria for exclusion from the study included function that was acceptable to the individual despite deformity, an extensively scarred soft-tissue envelope about the wrist, advanced osteoarthrotic changes in the radiocarpal joint, advanced osteopenia, and signs and symptoms of reflex sympathetic dystrophy. Neither advanced age nor osteoarthrotic changes in the distal radioulnar joint were considered contraindications to the corrective osteotomy.
Fifteen patients were men and ten were women; the average age was forty-six years (range, twenty-one to eighty-four years) (Table I). The injuries leading to the malunion included an extra-articular, volarly displaced fracture of the distal end of the radius (a Smith fracture) in seventeen patients; a volarly displaced metaphyseal fracture of the distal end of the radius with an intra-articular extension in two patients; and an unstable, dorsally displaced, extra-articular Colles fracture that had displaced into a volar deformity while the limb was immobilized in a cast in six patients.
The initial treatment had consisted of closed reduction and immobilization in a cast for twenty-two patients. The remaining three patients had had operative intervention before referral: two had had closed reduction and external fixation, and one had had closed reduction, percutaneous placement of smooth Kirschner wires, and external fixation.
The patients were referred to us an average of eight months (range, five to twenty months) after the fracture. All twenty-five patients reported pain in the wrist. Pain in both the radiocarpal and the radioulnar joint was evaluated. Pain was assigned 1 point if it was severe (occurring during activities of daily living or during rest), 2 points if it was moderate (occurring during activities requiring forceful grip), and 3 points if it was mild (occurring only at the extremes of motion but not interfering with function); 4 points was assigned if there was no pain. Ten patients reported no pain; twelve, mild pain; and three, moderate pain in the radiocarpal joint. Two patients reported no pain; four, mild pain; eleven, moderate pain; and eight, severe pain in the distal radioulnar joint.
All twenty-five patients had limited motion of the wrist as measured with a standard goniometer. Extension averaged 25 degrees compared with 69 degrees for the contralateral wrist, and flexion averaged 53 degrees compared with 69 degrees for the contralateral wrist. Supination of the forearm averaged 41 degrees, 46 degrees less than that on the contralateral side, and pronation averaged 64 degrees, 20 degrees less than that on the contralateral side. In fourteen patients, supination of the forearm was 45 degrees or less.
The average preoperative grip strength, as measured with a Jamar dynamometer (Therapeutic Equipment, Clifton, New Jersey), was seventeen kilograms-force compared with forty kilograms-force in the uninjured hand. Standard anteroposterior and lateral radiographs were made preoperatively, and measurements were carried out with Castaing's7 modification of the method devised by Gartland and Werley17. Ulnar inclination was measured, in degrees, as the angle between a line drawn parallel to the distal articular surface and a line drawn perpendicular to the radial shaft. Ulnar variance, the relationship of the distal end of the radius to the ulnar head, was measured, in millimeters, by determining the distance between a line drawn perpendicular to the long axis of the radius and tangential to the lunate facet of the radial articular surface and the distal extent of the ulnar head19,28. Volar inclination was measured, in degrees, as the angle between a line drawn tangential to the distal radial articular surface in the sagittal plane and a line drawn parallel to the shaft of the radius. Ulnar inclination averaged 14 degrees (range, -15 degrees to 32 degrees); ulnar variance, five millimeters (range, -1 to fifteen millimeters); and volar inclination, 24 degrees (range, 15 to 40 degrees).
Post-traumatic osteoarthrotic changes, seen on the preoperative radiographs, were graded according to the criteria of Knirk and Jupiter24. Mild changes represented slight narrowing of the joint space; moderate changes, marked narrowing and the presence of marginal osteophytes; and severe changes, complete loss of the joint space and the presence of marginal osteophytes and subchondral bone cysts. Seven patients had mild osteoarthrosis in the radiocarpal joint, and seven had mild and one had moderate osteoarthrosis in the distal radioulnar joint.
Operative Technique
Preoperative Planning
The goals of the opening-wedge osteotomy include anatomical restoration of the distal radial articular surface to establish a more normal distribution of load on the radiocarpal joint, improvement of the range of motion of the radiocarpal joint, and restoration of the anatomical relationship of the distal radioulnar joint29,32.
Anteroposterior and lateral radiographs of the contralateral wrist are used to determine the normal degrees of ulnar and volar inclination. The goals of the correction are to restore the articular alignment of the distal part of the radius to within 5 degrees of that on the contralateral side in the frontal and sagittal planes and to restore the articular congruity of the distal radioulnar joint.
The osteotomy is planned so that it will be transverse in the frontal plane and oblique in the sagittal plane. The osteotomy should be located as close to the apex of the deformity as possible, and the dorsal aspect of the periosteum should be preserved. With use of the measurements obtained from the radiographs of the contralateral wrist, the planning of the osteotomy is similar to that described previously for the treatment of a dorsal Colles-type deformity14,16, except that the current procedure is performed on the volar side of the radius. The correction of the ulnar inclination in the frontal plane will determine the trapezoidal shape of the interposed corticocancellous iliac-crest graft, with the larger dimension of the trapezoid being placed on the radial aspect of the osteotomy (Figs. 1-A, 1-B, 1-C, 1-D, 1-E, 1-F and 1-G). In the sagittal plane, the graft will form a triangular shape with its apex placed dorsally.
The distal radioulnar joint must also be considered in the preoperative plan. A negative ulnar variance of less than ten millimeters generally will be corrected with the radial osteotomy. A variance of ten millimeters or more may necessitate an alteration in the shape of the graft. In the latter instance, the distal radial fragment can be lengthened by sectioning the dorsal aspect of the periosteum and contouring the autogenous iliac-crest graft to a trapezoidal shape in the sagittal plane. Because this construct may be less stable than that in which the dorsal periosteal hinge remains intact, the limb must be immobilized in a below-the-elbow cast for six weeks. Radiographic changes of post-traumatic osteoarthrosis of the distal radioulnar joint or articular incongruence of the ulnar head may be judged sufficiently severe to necessitate an intraoperative arthrotomy of the distal radioulnar joint, with direct visualization of the articular surfaces. An ulnar shortening osteotomy is indicated if the normal ulnar variance cannot be restored with the distal radial osteotomy and interposition of corticocancellous iliac-crest graft14. An arthroplasty of the distal radioulnar joint is performed if there is residual articular incongruity of that joint despite a more normal alignment and length of the distal radial fragment4,5,13.
The pronation deformity of the distal radial fragment tends to be corrected when the flat surface of the plate used to secure the osteotomy site is applied to the volar aspect of the radius. If the deformity is associated with radial shortening and an ulnar variance of ten millimeters or more, a z-lengthening of the brachioradialis tendon may be necessary15.
Procedure
General endotracheal anesthesia is preferred because of the need for an autogenous corticocancellous iliac-crest graft. The patient is positioned supine, and the involved arm and the contralateral iliac crest are prepared and draped.
A volar operative exposure, between the tendon of the flexor carpi radialis and the radial artery, is obtained under pneumatic tourniquet control with use of the distal extent of the Henry approach21. The pronator quadratus muscle is elevated from the radial aspect of the distal end of the radius; the surrounding soft tissues are protected with small Hohmann retractors. A smooth 0.062 or 0.045-inch (0.157 or 0.114-centimeter) Kirschner wire is placed proximal to the site of the osteotomy, perpendicular to the long axis of the radius. The degree of planned correction in the sagittal plane is controlled by placing a 0.062-inch (0.157-centimeter) smooth Kirschner wire in the distal fragment in the predetermined angle of the deformity. These wires will help when the accuracy of the correction of the alignment is evaluated after the osteotomy. A small external-fixation frame, with one pin placed in the distal fragment and one pin placed in the radial diaphysis, is used to maintain the corrected alignment before placement of the bone graft, plate, and screws.
The osteotomy is created with a sagittal saw, preferably at the site of the original fracture. The osteotomy is wedged open with use of a small lamina-spreader clamp. If lengthening of ten millimeters or more is needed, a z-lengthening of the tendon of the brachioradialis and transection of the dorsal periosteal sleeve is performed. The autogenous corticocancellous iliac-crest graft is obtained and contoured, with its dimensions determined according to the preoperative plan (Fig. 1-C). The osteotomy and the intercalated bone graft are fixed with a 3.5-millimeter-angled T-shaped plate (Synthes, Paoli, Pennsylvania), which also facilitates correction of the pronation deformity of the distal fragment.
At the time of the osteotomy, five patients had a hemiresection arthroplasty of the distal radioulnar joint as described by Bowers4,5, and one of them (Case 10) also had open reduction and internal fixation of an ununited fracture of the ulnar styloid process.
Postoperative Regimen and Evaluation
Postoperatively, the wrist is supported by a volar plaster splint for two weeks unless lengthening of ten millimeters or more is needed, in which case a below-the-elbow cast is worn for six weeks. Exercises and activities of daily living are encouraged after the external support has been removed; however, activities against resistance and manual labor are not permitted until union has been confirmed radiographically, and it rarely is confirmed before eight weeks. The plate and screws are removed only if requested by the patient.
All patients were followed, throughout the course of treatment, by the two senior ones of us (D. L. F. and J. B. J.), who also performed the additional operative procedures. The most recent evaluation was based on subjective criteria, including pain in the radiocarpal or radioulnar joint, or both, as well as objective data, including the active range of motion of the wrist and forearm, grip strength as measured with a method similar to that used preoperatively, sensibility to light touch, and ability to engage in the preinjury occupation.
Preoperatively and postoperatively, we used the evaluation system previously reported for assessment of the functional results of corrective osteotomy of a dorsally displaced malunion of the distal end of the radius13,16,22. Pain at each of the two articulations was evaluated postoperatively with use of the same system that had been used before the operation. Flexion-extension of the radiocarpal joint of at least 130 degrees was assigned 4 points; 101 to 129 degrees, 3 points; 80 to 100 degrees, 2 points; and less than 80 degrees, 1 point. Rotation of the forearm ranging from 160 to 180 degrees was assigned 4 points; 140 to 159 degrees, 3 points; 120 to 139 degrees, 2 points; and less than 120 degrees, 1 point. Grip strength that was at least 80 per cent of that of the uninvolved hand was assigned 4 points; 65 to 79 per cent, 3 points; 40 to 64 per cent, 2 points; and less than 40 per cent, 1 point. A total score of 18, 19, or 20 points was considered very good; 15, 16, or 17 points, good; 12, 13, or 14 points, fair; and 11 points or less, poor. The overall preoperative score averaged 11 points (range, 7 to 15 points). Seventeen patients had a rating of poor; seven, fair; and one, good.
The sensory examination included testing for sensibility to light touch as well as assessment of two-point discrimination of the median, ulnar, and radial-nerve distributions. Work capacity was evaluated according to whether or not the patient was able to resume his or her preinjury occupation with or without restrictions.
Radiographs that had been made in the early postoperative period as well as those that had been made at the latest follow-up evaluation were used to assess osseous union, ulnar inclination, ulnar variance, volar inclination, and osteoarthrotic changes in the radiocarpal and distal radioulnar joints.
Student unpaired t tests were used to evaluate the extent of improvement in the range of motion, grip strength, and overall score between the preoperative and latest postoperative evaluations. A p value of less than 0.05 was considered significant.
The patients were followed for an average of sixty-one months (range, eighteen to 114 months) after the osteotomy (Table II). Eleven patients had an additional operative procedure before the latest follow-up evaluation. These procedures included removal of the plate and screws only in seven patients and removal of the hardware as well as a Bowers procedure and ulnar shortening, a Darrach resection, and a carpal tunnel release in one patient each. In the eleventh patient (Case 9), the osteotomy failed to heal, necessitating insertion of an additional graft of autogenous bone from the iliac crest as well as a new plate and screws; revision of a previous hemiresection arthroplasty of the distal radioulnar joint was done at the same time. The eleven secondary procedures were performed an average of eighteen months (range, twelve to twenty-eight months) after the osteotomy. Union of the fracture was documented in the other twenty-four patients an average of eight weeks (range, six to ten weeks) postoperatively.
At the latest follow-up examination, thirteen patients were pain-free. Of the remaining twelve patients, two continued to note mild pain in the radiocarpal joint, eight had mild pain in the distal radioulnar joint, and two had severe pain in that joint. Twenty patients rated their working capacity to be equal to that before the fracture, and five noted some residual disturbance in the overall function of the wrist that necessitated modification of their occupation.
The average supination of the forearm improved from 41 degrees (range, 0 to 90 degrees) preoperatively to 69 degrees (range, 20 to 90 degrees) postoperatively (p < 0.05). Only three patients had supination of the forearm that was 40 degrees or less. The average pronation of the forearm was 75 degrees (range, 40 to 90 degrees) postoperatively, representing an 11-degree improvement compared with the preoperative average of 64 degrees (range, 0 to 90 degrees) (p < 0.05).
The average extension of the wrist improved from 25 degrees (range, 0 to 60 degrees) preoperatively to 55 degrees (range, 20 to 75 degrees) postoperatively (p < 0.05). The average flexion of the wrist was 55 degrees (range, 30 to 80 degrees) postoperatively, representing an improvement of only 2 degrees compared with the preoperative value of 53 degrees (range, 20 to 90 degrees).
The average grip strength also improved, from a force of seventeen kilograms (range, one to thirty kilograms) preoperatively to a force of thirty kilograms (range, five to forty-eight kilograms) postoperatively and compared with an average force of thirty-nine kilograms (range, eleven to sixty kilograms) on the contralateral side (p < 0.05). Sensory examination revealed that sensibility to light touch and two-point discrimination were equal to those for the contralateral hand in all patients, including the one (Case 15) who had had a median-nerve release in the carpal tunnel.
The most recent radiographs revealed union at the site of the osteotomy in all twenty-five patients. In the patient (Case 9) who had had secondary bone-grafting and revision of the plate, the fracture united eight weeks after the reoperation.
The average ulnar inclination was 22 degrees (range, 10 to 25 degrees) compared with 14 degrees (range, -15 to 32 degrees) preoperatively. Volar inclination improved to an average of 5 degrees (range, 0 to 11 degrees) compared with the preoperative value of 24 degrees (range, 15 to 40 degrees). Ulnar variance averaged zero millimeters (range, -2 to five millimeters) compared with the preoperative value of five millimeters (range, -1 to 15 degrees).
Six patients had mild and one patient had moderate post-traumatic osteoarthrotic changes in the radiocarpal joint. Five patients had mild and one patient had moderate changes in the distal radioulnar joint. Of the seven patients who had radiographic evidence of post-traumatic osteoarthrosis in the radiocarpal joint, two had pain compared with three of the six patients who had similar radiographic changes in the radioulnar joint.
The overall functional result was rated as very good in ten patients, good in eight, fair in three, and poor in four. All four patients (Cases 3, 6, 16, and 24) who had a poor rating had residual pain in the distal radioulnar joint as well as limitation of the range of motion of the wrist and forearm. The overall postoperative score averaged 16 points (range, 11 to 20 points) compared with the preoperative average of 11 points (range, 7 to 15 points) (p < 0.01)
The need for operative procedures designed specifically for patients who have a symptomatic, malunited fracture of the distal end of the radius has long been recognized. The distal ulnar resection is attributed to Darrach8, who described it in 1913, but in fact it was mentioned as early as 1791 by Desault9. Operative correction through the radial deformity was described by Ghormley and Mroz20 in 1932 and has since become a well accepted reconstructive procedure for deformity following a dorsally displaced Colles-type fracture. In light of the relative rarity of volarly displaced fractures of the distal end of the radius compared with their dorsal counterparts33,34, it is not surprising that the information in the literature is sparse with regard to the indications and operative technique for corrective osteotomy of volar deformity13-15.
The indications for the operative treatment of the patients in the current series included pain as well as limitation of the mobility of the wrist and forearm. These symptoms can be readily explained by the consistent pattern of deformity that occurs in association with a volarly displaced fracture. The relationship between the accuracy of the anatomical repositioning after a fracture of the distal end of the radius and the quality of the functional result has been well documented25. An alteration in the relationship of the carpus to its supporting articulation at the end of the radius adversely affects the transmission of load. This is manifested by a decrease in grip strength as well as in motion of the radiocarpal joint, which, in a patient who has a volarly displaced fracture, decreases extension of the wrist23. Furthermore, the loss of ulnar inclination combined with the volar displacement of the distal radial fragment places the hand and wrist in a radial and palmarly directed position, substantially reducing the mechanical advantage of the extrinsic flexor tendons as they pass through the carpal tunnel, which also contributes to a decrease in grip strength15. The resultant improvement in grip strength after realignment of the deformity in our patients was due in large part to the salutary effect on the kinesiology of the wrist and its return to a more anatomical position at the end of the radius.
Displacement of the distal fragment also distorts the anatomical relationship of the distal radioulnar joint in the sagittal, frontal, and horizontal axes. Shortening of the radius in relation to the distal end of the ulna, as well as relocation of the distal end of the ulna so that it is dorsal to the radius, results in tightening of the triangular fibrocartilage complex, which limits rotation of the forearm1,4,18,32. The loss of congruence between the sigmoid notch and the ulnar head similarly impedes the rotation of the forearm. Distortion of the articular cartilage within the distal radioulnar joint also leads to a painful arc of motion, which was prevalent in our patients.
The decision to perform a reconstructive procedure on the distal radioulnar joint simultaneously with the corrective osteotomy of the distal end of the radius depends on a number of factors. These factors include radiographic as well as intraoperative findings of injury within the joint; failure to gain a congruent joint after completion of the osteotomy, which is more likely when the preoperative ulnar variance is ten millimeters or more; and residual loss of passive rotation of the forearm intraoperatively after stable fixation of the osteotomy site. One of us (D. L. F.) previously reported the results of combining a corrective osteotomy for the treatment of malunion of the distal end of the radius with a hemiresection arthroplasty of the distal radioulnar joint in fifteen patients13. Although most of those patients had had a dorsally displaced fracture, the favorable results in the current series support the performance of these procedures simultaneously when indicated.
It is also noteworthy that residual problems involving the distal radioulnar joint proved to be an important factor contributing to two of the four poor overall outcomes. At the time of the latest follow-up evaluation, sixteen of the twenty-five patients noted some residual discomfort in the distal radioulnar joint.
Even in this selected group of patients who were deemed good candidates for osteotomy, residual problems, particularly those involving the distal radioulnar joint, were common. Although this study was retrospective and the indications for the osteotomy were not based on fixed radiographic criteria, the results suggest that every effort should be made to obtain and maintain an anatomical reduction in the treatment of a volarly displaced fracture of the distal end of the radius.