Ulnar Lengthening Research Articles

WRIST DENERVATION PROCEDURES IN THE TREATMENT OF KIENBÖCK'S DISEASE

In almost all papers on wrist denervation, indications for denervation in Kienböck's disease has been mentioned without exact data. A detailed analysis of our clinical data on 61 patients proved the positive effect with respect to pain relief. In the 47 patients in which the denervation was combined with other procedures, such as radial shortening, ulnar lengthening, lunate excision, and replacement by silicone or tendon, pedicled pisiform transposition, and STT arthrodesis, a very high rate of patients (76%) had no complaints or pain only with heavy manual work. Of these treated patients, 88% were very or remarkably satisfied. About the same success rate was found in cases in which the denervation was applied as a single procedure. The extent of denervation was different; therefore, it can be concluded that partial or complete denervation has its value as an additional or single procedure in the treatment of Kienböck's disease, especially in the advanced stages (Decoulx's stages III and IV).

ULNAR LENGTHENING PROCEDURES

Ulnar lengthening redistributes axial compressive forces partially relieving those on the lunate, slowing or halting further progressive collapse. Long-term results are satisfactory, although restitution of the carpal anatomy is not obtained.

Preliminary experience with Ilizarov method in late reconstruction of radial hemimelia

We report the outcome of ulnar lengthening with the Ilizarov technique in five adults with radial hemimelia and previous wrist centralization. The indications for ulnar lengthening in these patients were either a functional deficit due to the short ulna or poor appearance that caused the patient significant unhappiness. All patients had a successful lengthening of the ulna, with a gain in length from 4 to 13 cm; however, the procedures were prolonged (7 to 25 months), and all patients experienced complications. At the time of follow-up examination no patient had residual pain or paresthesias. In four of five patients, although ulnar lengthening resulted in somewhat stiffer digits, it improved function of the extremity as a whole. When asked if they would repeat the lengthening, knowing what they know now, all five replied that they would. The technical difficulties encountered in these cases suggest a cautious approach to ulnar lengthening. This is a long, arduous, painful process that requires a psychologically robust patient. If the ulna is very short preoperatively, lengthening can enhance the volume of space accessible to the hand and in that way improve function.

Strain-gauge evaluation of lunate unloading procedures

A biomechanical study was undertaken to determine which procedure(s) most effectively relieve load from the lunate. Strain gauges were mounted on the lunates of 20 preserved cadaveric limbs. Three types of procedures were performed: scaphotrapeziotrapezoid arthrodesis, capitohamate arthrodesis, and ulnar lengthening. Load testing was performed both before and after the simulated fusions and ulnar lengthenings. Ulnar lengthening of 3 mm was the most effective method of lunate strain reduction. Capitohamate arthrodesis decreased compressive strain but increased shear strain. Scaphotrapeziotrapezoid fusion significantly increased both compressive and shear strain in the lunate. Of the three procedures that were tested, ulnar lengthening to create a neutral variance is the most reliable means of unloading the lunate.

Force transmission through the distal ulna: Effect of ulnar variance, lunate fossa angulation, and radial and palmar tilt of the distal radius

The relationship between the amount of force transmitted through the distal ulna and seven radiologically apparent anatomic parameters (ulnar variance, radial tilt, palmar tilt, lunate fossa angulation, carpal height, carpal ulnar distance, and ulnar head inclination) was examined in 58 fresh cadaver forearms. A positive, although very weak, relationship was found between the amount of force and the ulnar variance ( r = 0.44). This suggests that a clinically more positive ulnar variant wrist will not necessarily cause more force to be transmitted to the head of the ulna than a wrist with a more negative ulnar variance, primarily because the triangular fibrocartilage complex is thicker in arms with a more negative ulnar variance. Changes in ulnar variance of a forearm due to ulnar lengthening or radial shortening do, however, dramatically alter the force transmission. No other relationships were found between the ulnar force and the other radiologic parameters.

Ulnar Lengthening for Negative Ulnar Variance in Hereditary Multiple Osteochondromas

Ulnar Lengthening for Negative Ulnar Variance in Hereditary Multiple Osteochondromas

Effect on force transmission across the carpus in procedures used to treat Kienböck's disease

A simplified two-dimensional articulating force analysis (rigid body spring model) examined how different surgical procedures used for treating Kienböck's disease modify the force distribution across the carpus. A two-dimensional model of a carpus was loaded through the metacarpals by forces of up to 143 Newtons. The resulting intercarpal displacement and joint loadings were calculated for the intact wrist and for different simulated surgical procedures. The predicted total amount of force transmitted through the radio-lunate joint of the intact wrist averaged a 32% of the total radio-ulno-carpal joint load. Limited intercarpal fusions were found to reduce compressive loading at the radio-lunate joint by no more than 15% of the original load. Capitate shortening was successful in relieving radio-lunate forces, however, it dramatically overloaded the adjacent scapho-trapezial and triquetral-hamate joints. By contrast, a 4 mm lengthening of the ulna (or shortening of the radius) resulted in a 45% reduction of radio-lunate load with only moderate changes in force at the midcarpal and radio-scaphoid joints. On the basis of this study, radial shortening or ulnar lengthening significantly unload the lunate and are rationale procedures in the treatment of Kienböck's disease. Limitations regarding direct clinical application of this mathematical model are also discussed.

Pressures in the distal radioulnar joint: effect of surgical procedures used for Kienbock's disease.

Radial shortening and ulnar lengthening are two accepted surgical methods for treating Kienbock's disease. The effect of these procedures on the pressure within the distal radioulnar joint between the ulnar head and the sigmoid notch of the radius was experimentally evaluated in six fresh cadaver forearms. Radical shortening and ulnar lengthening led to increased pressure at the distal radioulnar articulation and caused shifting of the location of the center of pressure distally within the sigmoid notch. Radial displacement of the distal radial fragment at the time of radial shortening, however, decreased the peak pressures. Based on these experimental data, ulnar lengthening and radial shortening can be expected to alter the normal biomechanics of the distal radioulnar joint.

Ulnar impingement syndrome after Darrach procedure: Treatment by advancement lengthening osteotomy of the ulna

The Darrach procedure was the standard treatment for painful disorders of the radioulnar joint for several decades. However, recent articles have described unsatisfactory results after this procedure including dorso-palmar instability of the ulna, clicking upon rotation of the forearm, ulnar translocation of the carpus, and a painflul ulnar impingement syndrome. Management of these problems following an ulnar shortening procedure requires restoration of ulnar length to provide stability to the triangular fibrocartilage complex and ulnar sling mechanism. Also, recurrent impingement must be prevented. A technique of ulnar lengthening by advancement step osteotomy in conjunction with a “matched” resection of the advanced ulna is presented. Three case reports illustrate its use.

Operations for forearm deformity caused by multiple osteochondromas.

We reviewed 36 cases of forearm deformity caused by multiple osteochondromas in 30 patients and classified them into three types: Type I showed a combination of ulnar shortening and bowing of the radius secondary to osteochondromas of the distal ulna (22 forearms). Type II showed dislocation of the radial head, either with osteochondromas of the proximal radius (Type IIa, two forearms) or secondary to more distal involvement (Type IIb, five forearms). Type III had relative radial shortening due to osteochrondromas at the distal radius (seven forearms). Operations were performed on 16 forearms in 13 patients, with 92% of satisfactory results. For Type I deformity, excision of osteochondromas, immediate ulnar lengthening and corrective osteotomy of the radius are recommended. For Type IIa, excision of the radial head is necessary, and for Type IIb, we advise gradual lengthening of the ulna using an external fixator. Excision of osteochondromas alone gave good results in Type III deformity. Our classification gives a reliable indication of the prognosis and is a guide to the choice of surgical treatment.

Ulnar Lengthening in the Treatment of Kienbock's Disease

Ulnar Lengthening in the Treatment of Kienbock's Disease

Ulnar Lengthening and Shortening

Alteration in length of the distal ulna may provide an attractive alternative to more destructive procedures commonly used for the treatment of mechanical and degenerative problems at the distal radioulnar joint. Ulnar recession has shown effectiveness in ulnolunate impingement, triangular fibrocartilage tears, and symptomatic ulnar plus variance. It has also been effective in chondromalacia of the ulnar head in the sigmoid notch and in unstable distal radioulnar joints where recession alters the bearing surface and tightens the ulnocarpal ligamentous complex. Ulnar lengthening has been efficacious in relieving the symptoms of Kienböck's disease by decompressing the involved portion of the lunate and distributing joint compressive force on the triquetrum and medial lunate articular surfaces. It may also be of value in some instances of NDCI associated with an ulnar minus variant.

Kienböck's Disease

Kienböck's disease is a progressive disruption of the lunate secondary to avascular necrosis, which may be due to the lunate's precarious blood supply, external compression forces, and fractures of its surfaces. The treatment options for Kienböck's disease are based on the stage of the disease, defined by Stahl, and include immobilization, radial shortening or ulnar lengthening, intracarpal fusion, and prosthetic replacement. The prognosis for functional recovery is better in stage I and II disease, which emphasizes the need for early diagnosis.

Kienböcks Disease

Kienböck's disease is an isolated disorder of the lunate resulting from vascular compromise to the bone. The symptoms include wrist pain, limited range of motion, and decreased grip strength. The diagnosis is made from characteristic changes seen in the lunate on radiograms of the wrist. The severity of the disease can be categorized by staging the degree of involvement. This is helpful in guiding the practitioner through the maze of treatment options. Initial treatment of Kienböck's disease is conservative and includes immobilization, analgesics, and/or anti-inflammatory medication. If symptoms are not relieved, then based on the degree of involvement, several surgical options exist that will provide a successful result. These include autogenous tendon replacement arthroplasty, revascularization, radial shortening, ulnar lengthening, limited intercarpal arthrodesis, and silicone replacement arthroplasty. Salvage procedures for Kienböck's disease include wrist denervation, wrist arthrodesis, and proximal-row carpectomy. Currently, we prefer immobilization for treatment of stage I Kienböck's disease. For stage II, a revascularization procedure may be attempted or ulnar lengthening/radial shortening done, particularly if there is significant negative ulnar variance. In stage III, replacement arthroplasty and/or limited intercarpal arthrodesis is our treatment of choice, and for stage IV, one of the salvage procedures is indicated.

A biomechanical comparison of the methods for treating Kienböck's disease

Reduction of lunate compression is thought to promote revascularization of the lunate in patients with Kienböck's disease. The decompressing abilities of ulnar lengthening, radial shortening, capitate-hamate fusion, and scaphoid-trapezium-trapezoid (STT) fusion were examined in axially loaded, whole arm specimens. Lunate strain was monitored by electronic strain gauges and found to be proportional to the axial load borne by the bone. The STT fusions and the procedures to alter relative radial and ulnar length were successful in relieving lunate loading throughout a functional range of wrist motion and forearm rotation, but the capitate-hamate fusion was ineffective. Only the STT fusion resulted in a significant decrease in wrist range of motion. Incremental ulnar lengthening and radial shortening revealed that approximately 2 mm of length change maximizes lunate decompression without greatly increasing the risk of disorders of the distal radioulnar joint and ulnocarpal impingement.

Kienb??ck??s Disease

Further experience with ulnar lengthening in the treatment of 22 patients with Kienböck's disease confirms the efficacy of this procedure as observed in a previous series of 20 patients. In this procedure, the joint compressive force is removed from the trabeculae of the convex portion of the body of the lunate that is weakened by avascular necrosis. Subchondral fractures were present in at least 13 of the 22 patients. The technique of ulnar osteotomy, with interposition bone graft supported by a slotted bone plate applied prior to completion of the osteotomy, seems well established. Three patients were lost to follow-up and one required a secondary lunate excision for continuing pain. The remainder of the patients were well satisfied with the procedure.

Management of deformities of the forearm in multiple hereditary osteochondromas.

A patient with multiple hereditary osteochondromas may have any of several severe deformities of the forearm, the most common of which are ulnar deviation of the wrist associated with relative shortening of the ulna, bowing of either or both of the bones of the forearm, shortening of the forearm, and late dislocation of the radial head. The natural history of these deformities is progression, with variable weakness, functional impairment, and cosmetic deformity of the extremity. We describe the results, after a follow-up of at least two years, in eighteen patients who underwent major surgical procedures: excision of the osteochondromas (ten patients), ulnar lengthening with excision of the osteochondromas (three patients), and ulnar lengthening with radial hemiepiphyseal stapling (seven forearms of five patients). Early excision of the osteochondromas alone did not slow the progression of the deformity. Ulnar lengthening did, on occasion, correct the ulnar drift at the wrist, but the relative shortening of the ulna recurred. Distal radial hemiepiphyseal stapling should accompany ulnar lengthening if radiocarpal angulation or subluxation of the lunate occurs with ulnar shortening. Deformities of the forearm should be treated early and aggressively to prevent disability.

Kienböks Disease

Recent studies on the vascularity of the lunate and the kinematics of the wrist joint have better delineated the pathogenesis of Kienböck's disease. Although the precise cause has not been determined, a natural history of progressive elongation, collapse, and fragmentation has been well delineated. A classification based on the pathogenesis has helped categorize several recently conceived methods of treatment. When the diagnosis of Kienböck's disease is made early, before collapse of the lunate has occurred (stage I or II), ulnar lengthening, radial shortening, or capitate-hamate fusion appears to offer the best chances for revascularization. Presently, for patients with stage III Kienböck's disease, lunate silicone arthroplasty with or without intercarpal fusion appears to provide the best results. Proximal row carpectomy, total wrist arthroplasty, and wrist arthrodesis are reserved for patients with advanced, stage IV Kienböck's disease. Although many of these new techniques for treatment of Kienböck's disease have generated considerable enthusiasm, longer follow-up will be needed to determine whether the distortion of intercarpal relationships can be halted or reversed so that degenerative arthritis of the wrist joint can be prevented. Even if these procedures do not prove to be uniformly satisfactory, the recent application of treatment concepts based on a firmer scientific background has represented a significant step forward in the treatment of Kienböck's disease.

Ulnar lengthening in the treatment of Kienböckʼs disease.

Twenty patients with Kienböck's disease were treated with a modification of the Persson ulnar-lengthening procedure to remove compressive stress from the damaged lunate. After an average follow-up of thirty-seven months, relief of pain was satisfactory in eighteen patients who had returned to work (nine of whom had strenuous occupations), and two patients were dissatisfied because they had persistent pain and were not able to return to their previous occupations. Non-union at the site of the ulnar osteotomy occurred in three patients who were treated early in the series and was the result of inadequate internal fixation or insufficient duration of protective splinting. All three of the patients had satisfactory results after replating and bone-grafting. The procedure appears to help to maintain carpal height, prevent further collapse of the lunate, encourage consolidation of the fragmented lunate, and increase grip strength. Except for ulnar deviation, which the procedure may further diminish, the postoperative motions of the wrist were moderately improved.

Les différentes méthodes thérapeutiques

Among all treatments, whether surgical or not, one should remember immobilization in a cast often useful but not sufficient and ulnar lengthening or radius shortening both aiming at widening the lunate cavity and restoring a normal anatomy to the wrist. These are the only valuable methods in the long-term follow-up (30 years or more).