This report introduces a technique for treating >5 cm of bone loss from the distal part of the ulna due to tumor resection or trauma. The distal part of the forearm is stabilized by an advancement lengthening osteotomy of the ulna in combination with a ligamentoplasty with a portion of the flexor carpi ulnaris tendon. We present the cases of two patients in whom this technique was used to treat giant-cell tumor of the distal part of the ulna. The patients were informed that data concerning their cases would be submitted for publication, and they consented.
Two patients, an eighteen-year-old man (Case 1) and a forty-eight-year-old woman (Case 2), were referred to our institution with a symptomatic mass in the distal part of the right forearm. Radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) scans suggested the diagnosis of giant-cell tumor (Fig. 1). This diagnosis was confirmed by a surgical biopsy and histopathological study in each patient. Neither patient had evidence of metastatic giant-cell tumor.
The surgical technique used to treat these lesions was essentially the same for both patients. We performed an en bloc resection of the tumor, with the resection margin 3 cm proximal to the tumor as seen on the preoperative MRI. The gap after resection was 8 cm in one patient and 6 cm in the other patient. We performed longitudinal ulnar osteotomies of 8 cm and 6 cm, for lengthening of 6 cm and 4 cm, respectively, because a minimum overlapping length of 2 cm is needed for fixation. The reconstructed distal end of the ulna was stabilized with a ligamentoplasty in both cases.
With the patient under regional anesthesia and use of an upper-limb tourniquet, the patient was positioned supine. The surgical approach resected the biopsy scar on the ulnar side of the wrist, with the surgical incision extending from the base of the fifth metacarpal to the midpart of the ulnar shaft between the dorsal and palmar skin. The extensor retinaculum was incised between the fifth and sixth extensor compartments. A large en bloc excision of the tumor was performed by making a step-cut osteotomy 3 cm proximal to the tumor (Fig. 2).
The distal part of the ulna was reconstructed through a longitudinal osteotomy of the proximal part of the ulna with use of an oscillating saw (Fig. 3). The osteotomy length was adjusted to reach the ulnar notch on the radius, plus the amount needed for fixation. Fixation was achieved with 3.5-mm compression screws. Any spurs or uneven surfaces on the distal osteotomy site were removed with a saw. An anteroposterior drill hole was created, 2 cm proximal to the new distal end, to allow the passage of half of the flexor carpi ulnaris tendon, still attached distally, for the tenodesis1. The half-flexor carpi ulnaris was secured to itself with running sutures. We also fixed the pronator quadratus to the dorsal edge of the new distal aspect of the ulna using the same approach (Fig. 4).
Wound closure was performed over suction drainage. The arm was immobilized in an above-the-elbow cast in a neutral position for six weeks, with early finger mobilization. Following cast removal, each patient was encouraged to perform active movements of the wrist and forearm without a specific protocol. Both patients were allowed to return to full activities three months after surgery, when bone healing was present.
At the final follow-up appointments, both subjective evaluations (pain and satisfaction) and objective evaluations (mobility; force; Quick Disabilities of the Arm, Shoulder and Hand [QuickDASH] score; and radiographs) were performed for each patient.
At thirty-five months after surgery, Case 1 had a full range of wrist motion, no pain, and a grasp-strength deficit of 5% when compared with the contralateral side (Fig. 5). The QuickDASH score was 0. The immediate postoperative radiograph and the last follow-up radiograph (made thirty-five months after surgery) showed no change and good stability of the distal part of the ulna (Fig. 6).
At twenty-four months after surgery, Case 2 had an almost full range of wrist motion, with a 20° loss of pronation. She had an 8% reduction in grasp strength when compared with the contralateral side. The QuickDASH score was 8. Radiographs made at the last follow-up evaluation showed a healed osteotomy site with no resorption.
Both patients were very satisfied with the results and had no pain or instability of the distal radioulnar joint. Clinical maneuvers demonstrated no radioulnar convergence and no dorsovolar instability in either patient. They both returned to their previous level of activity.
Giant-cell tumors frequently occur in the distal part of the forearm, but only 1% of all giant-cell tumors occur in the distal part of the ulna2. Curettage or wide resection is considered for aggressive benign giant-cell tumors (grade 3 according to the classification system of Campanacci et al.3) that involve cortical breakthrough4. Wide resection of the distal part of the ulna can lead to radioulnar instability and also cause instability in the ulnar aspect of the carpus5.
In cases involving substantial distal ulnar resection, the question of whether the distal ulnar stump should be reconstructed and stabilized arises.
Some authors4,6 have stated that there is no need for reconstruction, even if the defect accounts for 50% of the initial ulnar length. Wolfe et al.6 found that patients who had undergone resection involving 25% to 50% of the ulnar length had a 14% decrease in wrist movement and a 25% decrease in strength compared with the contralateral side. Cooney et al.4 found no decrease in the range of motion but a 15% reduction in grasp strength.
Other authors5,7,8 have preferred to stabilize the distal stump by using a ligamentoplasty without osseous reconstruction. Several ligamentoplasties that involve different tendons, such as the palmaris longus tendon or the extensor carpi ulnaris tendon, have been described. Ligamentoplasties aim to limit ulnar stump instability, which can lead to poor functional results. However, all of the patients in the studies cited above5,7,8 had a loss in strength of as much as 50% when compared with the contralateral side.
Several techniques for ulnar reconstruction and stabilization, ranging from autografts to prosthetic replacement9-11, have been proposed. Structural grafts, such as tissue from the iliac crest or a vascular or avascular fibular graft, introduce the risk of more complications (nonunion and fracture) and donor-site morbidity. The use of allografts10 and prostheses9,11 has also been reported, with normal DASH scores and full wrist motion as results, but long-term follow-up is not yet available.
For the two active patients in our case report, the goal was to maintain wrist movement and achieve stability while limiting the number of surgical procedures. Reconstruction of the length of the ulna offers good anatomic conditions to allow a ligamentoplasty to be done. The combination of both techniques restores the length of the ulna and stabilizes the ulnar stump, which limits the tendency for subluxation and impingement of the reconstructed ulna on the radius.
We have adapted the principle of the lengthening osteotomy described by Watson and Brown12 for the treatment of distal ulnar instability after a Darrach procedure, with good results in terms of conserving movement and strength and with no sign of instability in their study. They achieved 2 to 3 cm of length, less than half the length achieved in our patients. Hove and Helland13 reported a similar technique but with a resection limit of 3 cm and the addition of an iliac bone graft. Our technique without bone-grafting allowed the reconstruction of a defect of 5 cm or more in the distal part of the ulna.
Both of our patients reported good subjective results and had QuickDASH scores equal to those in the general population. At their final follow-up appointments, the two patients had no instability and an almost full range of movement at the wrist.
Our technique, which may have a lower risk of infection, is simpler than reconstruction techniques that use an allograft or a prosthesis. The disadvantage of our technique is that later prosthetic replacement, if needed, will be more challenging as a result of the postoperative deformity of the medullary canal of the ulna.
In cases of wide en bloc resection of the distal part of the ulna, a combined lengthening osteotomy and ligamentoplasty appear to be useful for reconstructing the distal part of the forearm. This technique conserves the mobility and strength of the wrist and recreates a balance between the radius and the ulna. A larger series of cases is needed to confirm that the results of this technique are reliably reproducible.
Note: The authors thank Dr. Marc Andre Grave (Sherbrooke, CA) for help with the English language.