INJURIES OF THE ARTICULAR DISC AT THE WRIST

Transcription

1 INJURIES OF THE ARTICULAR DISC AT THE WRIST H. M. COLEMAN, TORONTO, CANADA From the Toronto East General and Orthopaedic Hospital Injury to the fibrocartilaginous disc between the radius and ulna has long been considered a cause of disability after Colles s fracture. First suggested by Petit in 1726, the injury has received little written confirmation. More has appeared in publications in foreign languages that might occur (Gibson 1925; Guillermo 1947; Hoegenk and Reske 1956; Mayer 1935; Peycelon 1938; Rampo and Pietrogrande 1949; Taylor and Parsons 1938). Platt (1935), referring to detachment of the fibrocartilage from the lower end of the ulna in Colles s fractures, reported: I have no statistical data, for clinical proof of its existence is rarely forthcoming. than in English, chiefly individual case reports and speculation about the types of damage The disc is fairly taut in all positions of rotation of the forearm, so that any disruption of the inferior radio-ulnar joint must be accompanied by injury of this structure or avulsion of one of its bony attachments. It is strange that such tears are seldom mentioned in articles concerned with excision of the lower end of the ulna or repair for dislocation of the inferior radio-ulnar joint. The purpose of this paper is to report the findings in fourteen cases in which a torn disc was found at operation, and in eight others in which a damaged disc was suspected. In some of these eight cases further evidence was obtained from arthrographs of the wrist. In only five of the operation cases was there an associated fracture or dislocation. The remaining nine presented isolated tears of the disc produced by a specific mechanism of injury. TABLE I MECHANISM OF INJURY CAUSING TEAR OF THE ARTICULAR DISC OF THE WRIST Number of wrists Extreme extension and pronation 8 Extreme extension and supination I Colles s fracture... 4 Disruption of inferior radio-ulnar joint associated with fracture of I head of radius... Total MECHANISM OF INJURY If the fingers of one hand are grasped with the other hand and the wrist is forced into extreme extension and pronation, strain followed by pain will be felt in the region of the head of the ulna. The inferior radio-ulnar joint is the first fixed point in the chain of articulations where the violence of the force is expended on soft structures. This manoeuvre was applied forcibly to both wrists of a fresh cadaver and the joints were opened. Each articular disc was found to be detached from the radius (Fig. I). In eight of the operation cases the injury was caused by extreme extension and pronation of the wrist and in one by extreme extension with supination. A typical example was in a student nurse who was watching a game of 522 THE JOURNAL OF BONE AND JOINT SURGERY

2 INJURIES OF THE ARTICULAR DISC AT THE WRIST 523 football when the ball was kicked at her and she put out her hand to ward it off. The ball struck her outstretched fingers. driving her wrist into violent extension and pronation (Fig. 2). The mechanism of injury in the fourteen operation cases is shown in Table I. FIG. 1 Avulsion of the disc from the radius produced experimentally. The proximal surface of the wrist joint is seen and a probe has been inserted into the defect at the radial attachment of the disc. FIG. 2 A football striking this girl s outstretched fingers drove her wrist into extension and pronation, producing a surface tear of the articular disc. THE CLINICAL PICTURE These patients are seen by the orthopaedic surgeon because of persisting symptoms after a definite wrist injury. In the acute stage there has been swelling with severe pain, and in the absence of radiological evidence of fracture or dislocation a diagnosis of sprain has been made. Strapping or plaster immobilisation has been used for varying periods. The pain is well localised to the dorsum of the wrist over the inferior radio-ulnar joint and is aggravated by resisted pronation or supination, as in using a wrench or a screwdriver. In one instance (Case 4) the pain and tenderness were on the anterior surface of the wrist. Weakness of grip has been common, and a click, which is often painful, has been noticed in all cases. There has been no instance of a locked wrist as described by Michaelis (1940). Physical findings-tenderness localised to the dorsum of the inferior radio-ulnar joint is almost constantly present. The lower end of the ulna may be slightly more mobile than usual, and pushing it forwards and backwards is painful. The click can usually be demonstrated by the patient or produced by manipulation of the wrist. Wrist movements may be slightly restricted and the grip may be weaker than on the opposite side. Arthrographic findings-arthrographs ofthe wrist have been helpful in establishing the diagnosis when the disc is completely torn. Hypaque (sodium diatrizoate in 50 per cent aqueous solution) diluted with an equal amount of 1 per cent Novocain is used. The patient s hand is placed palm down and the needle is introduced into the wrist joint just distal and slightly dorsal to the tip of the ulnar styloid process. Under fluoroscopic control a few drops of the contrast medium are injected to make sure that the needle is in the joint. (Extra-articular injection confuses the interpretation of the films.) About five millilitres of fluid can be injected before the patient complains of tightness or pain. If the injection is watched under the screen the fluid may be seen flowing from the wrist joint into the inferior radio-ulnar joint and the site of a perforation may be determined. It must be borne in mind that there is often a foramen in the normal disc and that perforations may develop from degenerative changes (Fig. 10). Most anatomy books state that the disc is occasionally perforated. Liebolt (1938) studied VOL. 42 B, NO. 3, AUGUST 1960

3 524 H. M. COLEMAN the articular discs of the wrists of eighty cadavers and found 306 per cent to be perforated. Grant (1947) found 50 per cent perforated. These perforations were in the central part of the disc and, as the specimens were from subjects past middle age, many might have been due to degenerative changes and were not normal features. The passage of fluid from the wrist into the inferior radio-ulnar joint cannot be regarded as entirely diagnostic of a tear, but the TABLE II TYPES OF DAMAGE TO THE ARTICULAR DISC Number of wrists Avulsion from radius.. 6 Surface tear Avulsion from ulna... I Transverse Fragmented Total site of the perforation, if determined, is very helpful. Irregularity and displacement of the disc have been shown (Figs. 3 and 4) as well as pocketing of fluid around the separated ulnar attachment (Fig. 5). A normal arthrograph is obtained when there are superficial or microscopic tears of the disc. CLINICAL MATERIAL Of twenty-two patients, aged fourteen to sixty, who had symptoms and signs suggestive of a torn articular disc, fourteen were operated upon and the pathology was demonstrated. Five types of tear were found (Table II). Detachment from the radius was most common (Figs. 7 and 10). The superficial or microscopic tears were on the proximal surface of the disc. This looked rough, but the damage was best shown microscopically (Fig. 12). Fibrillation of the articular cartilage of the head of the ulna was noted once in relation to a surface tear of ten months duration. In only one case of detachment from the ulna was the ulnar styloid process seen at operation to have come away with the fibrocartilage. A completely fragmented disc was found in one case in which disruption ofthe inferior radio-ulnar joint had occurred in association with a fracture of the head of the radius. The radial head had been removed and the radius had moved upwards (Fig. 4). The first disc removed was infiltrated and the surface studded with deposits ofcalcium. The degenerative changes present undoubtedly contributed to the surface tear produced by lifting a weight of 1 50 pounds. In two cases of malunion of fractures of the lower end of the radius a torn articular disc was found at operation for removal of the lower end of the ulna. The discs were left in place and the symptoms persisted. The disability in the remaining eight patients was not sufficient to warrant operation, although arthrographs in two (Figs. 3 and 5) were positive. DIFFERENTIAL DIAGNOSIS The accurately localised pain and tenderness associated with a click in the inferior radio-ulnar joint make the diagnosis relatively easy. A chronic or recurrent sprain of the wrist does not produce such localised symptoms or signs. Subluxation or dislocation of the lower end of the ulna is readily distinguished. A subluxating carpal bone giving rise to a THE JOURNAL OF BONE AND JOINT SURGERY

4 INJURIES OF THE ARTICULAR DISC AT THE WRIST 525 FIG. 3 Arthrograph showing a large gap between the radius and ulna with the disc retracted to the region of the ulnar styloid. This tear was associated with a comminuted Colles s fracture but the disability was not severe enough to warrant operation. 4 FIG. Figure 4-Arthrograph showing a disrupted inferior radio-ulnar joint from which a fragmented disc was removed. Note the upward displacement of the radius which was associated with a fracture of the head of the radius. The fluid has passed through the fragmented disc, which it outlines. Figure 5-Arthrograph showing passage of the fluid to the inferior radio-ulnar joint at the ulnar attachment of the disc. The clinical findings were typical but the disability was not severe enough to warrant operation. VOL. 42 B, NO. 3, AUGUST 1960

5 526 H. M. COLEMAN clicking, painful wrist must be kept in mind. Radiographic examination will rule out many of the causes of persistent pain in the wrist such as avascular necrosis, degenerative arthritis, calcium deposits, cysts and chronic infective processes. If the tear is associated with a Colles s fracture or dislocation of the head of the ulna it is difficult to determine how much of the disability is due to the torn disc. One patient who had a torn disc removed after a severely comminuted Colles s fracture has not been able to continue as a carpenter but is able to run a farm unassisted. Another man with a similar malunion of his radius and a torn disc (Fig. 3) is not disabled enough to warrant operation. TECHNIQUE OF OPERATION The inferior radio-ulnar joint is approached through a transverse skin incision on the ulnar side of the dorsum of the wrist at the level of the lower end of the radius. The skin and subcutaneous tissues are widely retracted and a longitudinal incision is made to the ulnar side of the common extensor tendons into the sheath of the extensor digiti minimi. Retraction of these tendons exposes the capsule of the inferior radio-ulnar joint which is dissected offthe disc to open thejoint. The dorsal surface ofthe disc is grasped and is dissected from its attachments to the radius. ulna and anterior capsule with a fine-bladed scalpel. Great care is necessary to avoid damaging the articular surfaces or tearing the disc. As with the cartilages of the knee, the pathology is often seen only when the disc is partly or completely removed. The joint capsule is easily closed and the edges of the fibrous tendon sheath are brought together. The wrist is protected for two weeks with a plaster slab before physiotherapy is begun. The operation is more difficult when an anterior incision is used, as was done once when an associated lesion of the ulnar nerve required exploration. CASE REPORTS Case 1-A man aged thirty-four was removing the steel plug from an oil drum with a special type of wrench held in his right hand. He reinforced his grip with the left hand, which grasped the ulnar border of the right (Fig. 6). The resistance gave way suddenly, producing extreme extension and pronation of his wrist. He felt a snap in the wrist, which was followed in a few hours by the appearance FIG. 6 Case 1-To remove a plug from an oil drum this man used his left hand to apply extra force. The plug gave way suddenly and an extension-pronation force was applied to the wrist, producing the lesion seen in Figure 7. FIG. 7 Case I-The excised disc, which had been avulsed from the radius. The irregular free edge is seen at the top of the specimen. (Metric scale). THE JOURNAL OF BONE AND JOINT SURGERY

6 INJURIES OF THE ARTICULAR DISC AT THE WRIST 527 of swelling on the dorsum. When seen two months later he complained of pain on rotation of the forearm and of a painful click in his wrist which he could reproduce. His grip was weak ; dorsiflexion and palmar flexion of the wrist were slightly restricted and the dorsal surface of the radio-ulnar joint was tender. Manipulation of the lower end of the ulna was painful. At operation the articular disc was found to be detached from the radius (Fig. 7). The patient returned to his original work of delivering oil drums and has excellent strength with full painless movement. Case 2-A man aged fifty-one was working on the end of a six-inch pipe weighing about 100 pounds when it rolled off the stand catching his thumb and pulling his wrist into extreme extension and supination (Fig. 8). After this his wrist was painful on use and he noticed a click. His grip with this FIG. 8 FIG. 10 Case 2-This man s thumb was caught in a heavy pipe which rolled, pulling his wrist into extreme extension and supination (Fig. 8). The arthrograph (Fig. 9) showed a communication between the wrist and the infertor radio-ulnar joint. The specimen (Fig. 10) shows that this finding cannot be accepted as diagnostic of a tear. The upper edge of the specimen was detached from the radius so as to leave the beak-like process free in the joint. The oval perforation is an example of the degenerative perforation reported to be present in 50 per cent of older patients. hand was weaker than that of the opposite side. There was tenderness over the inferior radio-ulnar joint, and rotation caused a click. An arthrograph (Fig. 9) revealed a communication between the wrist and the inferior radio-ulnar joint. Four months after injury the cartilage was removed. Its attachment to the radius had been torn (Fig. 10). Six weeks after operation he returned to pipe making and he now has full use of his hand without pain. Case 3-A man aged thirty-two was holding an eighty-pound pane of glass by its upper edge when it slipped out of his left hand. The pane fell to the floor with his right hand attempting to hold the weight. As the glass shattered on striking the floor the already extended wrist was driven into extreme extension (Fig. 1 1). Swelling and pain, with numbness of the fourth and fifth fingers, were followed by tenderness over the inferior radio-ulnar joint and by a painful click on pronation and supination. He also had hypoaesthesia over the ulnar nerve distribution in the hand. As the arthrograph showed no abnormality the wrist was treated by immobilisation and strapping for several months. Because of persistent symptoms and inability to work, the ulnar nerve and inferior radio-ulnar joint were explored through an anterior incision and the disc was removed. No lesion of the nerve was found but the disc was torn on its proximal surface (Fig. 12). Aching pains and weakness of grip persisted. necessitating lighter work for a year. When last seen two years after operation he had no complaints and had made a full recovery from the lesion of the ulnar nerve. VOL. 42 B, NO. 3, AUGUST 1960

7 528 H. M. COLEMAN FIG. II FIG. 12 Case 3-Figure li-the mechanism of injury here illustrated shows a heavy pane of glass held in the right hand being shattered as it strikes the floor, driving the wrist into extreme extension. Figure 12-A photomicrograph of a section of the disc showing a superficial tear. The proximal irregular surface is in marked contrast to the smooth distal surface seen at the bottom of the specimen. I FIG. 13 FiG. 14 Case 4-Figure l3-arthrograph. Fluid has passed to the inferior radio-ulnar joint. This finding in a young individual may be regarded as diagnostic of a tear. The specimen (Fig. 14) shows the excised disc. A transverse tear runs from the undetached radial side (at the top). The tear is nearer the anterior edge of the disc, which may explain why pain and tenderness were on the anterior aspect of the radio-ulnar joint. Case 4-An Italian mechanic aged twenty-three was standing on a machine holding a pipe above his head when his left foot slipped and he suffered a severe extension strain of his right wrist. Persistent pain with weakness of grip followed so that he was unable to do his ordinary work. The pain was over the front of the wrist on the ulnar side and there was tenderness at that site. Supination of the forearm was limited by 20 degrees and the grip was much weaker than that of the left hand. A click was present on certain movements of the wrist. An arthrograph (Fig. I 3) showed that the fluid had passed into the inferior radio-ulnar joint from the wrist. At operation a transverse tear of the disc nearer its anterior side was found ( Fig. 14). The site of the tear could account for the pain and tenderness being on the front of the wrist. Eight months after operation the patient s only complaint was of low back pain. The wrist was symptomless when he was at his regular work. THE JOURNAL OF BONE AND JOINT SURGERY

8 INJURIES OF THE ARTICULAR DISC AT THE WRIST 529 SUMMARY AND CONCLUSIONS 1. A specific mechanism of injury can produce a tear of the articular disc of the wrist without any associated bony lesion. 2. Torn discs have been found associated with Colles s fractures and with dislocation of the inferior radio-ulnar joint. 3. The injury gives rise to clear-cut symptoms and definite physical signs. 4. Operation in fourteen cases has shown five types of tear of the disc. 5. Arthrographs of the wrist are helpful in establishing the diagnosis. 6. In isolated tears removal ofthe disc relieves the symptoms and does not prejudice function. 7. If there is other joint injury, removal of the disc cannot be expected to give as satisfactory a result. I wish to thank Mrs Louise Gordon for the sketches and Mr Maurice Delight for the radiographic reproductions and photographs. REFERENCES GIBSON, A. (1925): Uncomplicated Dislocation of the Inferior Radio-Ulnar Joint. Journal ofbone and Joint Surgery, 7, 180. GRANT, J. C. B. (1947): An Atlas of Anatomy. Second Edition, p.74. Baltimore: The Williams & Wilkins Company. GUILLERMO, J. (1938): Le fibro-cartilage de l articulation radio-cubitale inf#{233}rieure chez l adulte. Revue d Orthop#{233}die, 25, 125. HOEGEN, K., and RESKE, W. (1956): Ver#{228}nderungen an der dreieckigen Bandscheibe des distalen Radio-Ulnar- Gelenke (Em Beitrag zur Klinik und Pathologie). Zeitschrift f#{252}rorthop#{228}die, 87, 525. LIEBOLT, F. L. ( I 938) : Surgical Fusion of the Wrist Joint. Surgery, Gynecology and Obstetrics, 66, 1,008. LIPPMANN, R. K. (1937): Laxity of the Radio-Ulnar Joint following Colles Fracture. Archives of Surgeri, 35, 772. MAYER, J. H. (1939): Colles s Fracture. British Journal ofsurgeri, 27, 629. MICHAELIS, L. S., (1940): Locking Wrist. Lancet, ii, 229. PETIT, J. L. (1726): A Treatise on the Diseases of Bone. Quoted by Platt (1932). PEYCELON, R. (1938): A propos de la pathologie du fibro-cartilage de l articulation radio-cubitale inf#{233}rieure. Revue d Orthop#{233}die, 25, 551. PLATT, H. ( 1932) : Colles s Fracture. British Medical Journal, ii, 288. PLATT, H. (1935) : Colles Fracture. Surgery, Gynecology and Obstetrics, 60, 542. RAMPOLDI, A., and PIETROGRANDE, V. (1949): Lesioni traumatiche della articolazione radio-ulnare distale. Ortopedia Traumatologia dell Apparato Motore, 17, 311. TAYLOR, C. W., and PARSONS, C. L. (1938): The Role of the Discus Articularis in Colles Fracture. Journal of Bone and Joint Surgeri, 20, 149. VOL. 42 B, NO. 3, AUGUST 1960