2. Case Reports2.1. Case Report 1Patient A is a 21-year-old right-handed man of Dutch origin, who presented at the outpatient clinic with pain in the left wrist and an abnormal position and function of both elbows and wrists. He complained about inability to rotate the left forearm with a squeaking sensation and pain around the wrist. There was no trauma in the past. Examination of the wrist revealed a dorsal and palmar flexion of 70 degrees. Radial and ulnar deviation measured respectively 20 and 10 degrees with pain radial over the SL region. The same pain appeared with the Watson scaphoid shift test and to a lesser extent during the midcarpal shift test. Proand supination were both 45 degrees. Examination of the contralateral wrist demonstrated the same range of motion without pain. Radiographic examination of both hands showed bilateral a synostosis of scaphoid and trapezium. It also showed an ulna-plus configuration of 4.4 mm and a SL gap of 5.5 mm on the left side and an ulna-plus configuration of 3.0 mm and a SL gap of 4.0 mm on the right side (Figures 1-4). A radiograph of the left elbow showed a congenital dislocation of the radial head and a radiograph of the right elbow showed a mild dysplastic joint (Figures 5 and 6). Because of diminishing complaints, conservative treatment consisting of a removable wrist cast was advised, which was only used by this patient for a few weeks.
2.2. Case Report 2Patient B (45-year-old) is the mother of Patient A. She presented at our outpatient clinic because of progressive pain in both wrists, mostly in the right wrist. Clinical examination showed pain with palpation at the location of the scaphoid, lunate and scaphoid-trapezium-trapezoid joint with a dorsal flexion of 70 degrees and palmar flexion of 15 degrees. Proand supination measured 30 respectively 80 degrees with a radial and ulnar deviation of both 10 degrees. X-rays and CT-scans of both hands showed bilateral a Madelung deformity with radiocarpal osteoarthritis. There was also a bilateral synostosis of the scaphoid and trapezium with a normal SL distance (Figures 7 and 8). In this patient, a wrist arthrodesis was performed at the right side at her special request.
2.3. Case Report 3Patient C, an 18-year old woman, presented at our clinic
because of a painful click due to slight posterolateral rotational instability of the right forearm after a humerusfracture. There were no complaints of the wrist. Because of the rotational impairment, wrist X-rays were also taken. These showed a proximal radio-ulnar synostosis (Figure 9) and a coalition between lunate and triquetrum (Figures 10 and 11). Patient was advised to remove the intramedullary humerusnail. Because the carpal synostosis was asymptomatic, an expectative policy was followed.
2.4. Case Report 4Patient D is a 38-year-old, otherwise healthy, woman with long lasting complaints of the left wrist, which in
crease during loading. There is also pain during driving and cycling. At clinical investigation there is pain over the thenar and the volar site of the distal forearm. Range of motion and stability are normal. Translation of the CMC 1 joint, pressure over the STT joint and the Watson test are painful without signs of instability. Midcarpal shift test is not painful. X-rays of the wrist show an irregular STT joint. An additional MRI shows a synostosis between capitate and trapezoid with slight bone marrow edema (Figure 12). A conservative policy was followed and patient was referred to a rehabilitation clinic.
2.5. Case Report 5Patient E, an 18-year-old boy, presented at the emergency department after a fall of his bike with pain on both wrists. The right wrist showed some pain on the ulnar side of the carpus without swelling or limited range of motion. The left wrist showed swelling and pain over the scaphoid and distal radius with a limited range of motion. X-ray of both wrists showed no fractures, but a bilateral synostosis of capitate and hamate (Figures 13 and 14). At follow-up the complaints had disappeared and an expectative policy was followed.
2.6. Case Report 6Patient F is a 41-year-old woman, who presented at our outpatient clinic because of pain in the right hand, most in the second, third and fourth finger. Clinical investigation showed no abnormalities. X-rays of the hand showed a coalition between hamate and capitate and a coalition between triquetrum and pisiform (Figures 15 and 16). An immobilising wrist splint was fitted.
3. DiscussionCongenital carpal coalition originate from lack of cavita-
tion at the site of the future joint space with subsequent chondrification and ossification during the 4th to 8th weeks of intrauterine life [1,3,4]. Almost every possible combination of congenital carpal synostosis has been reported [2-24]. The most common synostosis anomaly of the carpus is the lunate-triquetral coalition, followed by synostosis between the capitate and hamate [4,15,16]. For certain types of coalitions, there is a higher incidence amongst African people [1,3,19]. Synostoses can present as an isolated entity or can be part of a syndrome with multiple congenital anomalies, such as Steel syndrome, Muenke syndrome, congenital synspondylism, spondylocarpotarsal synostosis syndrome and arthrogryposis multiplex congenita [1]. Isolated synostoses tend to involve only two bones of the same carpal row. In contrast, syndromic carpal synostoses tend to involve more than two bones and cross the proximal and distal carpal rows [10, 22]. Synostosis of carpal bones can sometimes be hereditary and the trait is often transmitted as a Mandelian dominant factor, which is not sex linked [7].
Carpal synostosis normally does not interfere with the function of the wrist and is only rarely symptomatic [1]. However, some patients got pain and discomfort. After trauma, patients can complain about pain, a fracture through the synostosis, non-union after a fracture through the synostosis or a scaphoid luxation [13,18,24].
Minnaar de Villiers classified lunotriquetral coalitions into four radiological types (11, Table 1). This classification may be applicable to other carpal coalitions as well [21,22]. In Types 1 and 2 there can be some movement because of incomplete coalition, causing pain [14]. In Type 3, loss of movement between the fused carpal bones leads to a compensatory increase in motion at surrounding joints and can lead to stretching of the normal soft-tissue restraints, which can cause pain in stressful
Table 1. Classification of lunotriquetral coalitions according to Minnaar deVilliers [11].
conditions [10].
In the present report different congenital carpal coalitions are mentioned in patients without known syndromes: synostosis of scaphoid-trapezium, lunate-triquetrum, triquetrum-pisiform, capitate-trapezoid and capitatehamate. One patient however had bilateral elbow problems. Other coalitions including nearly every possible combination of bones are described in the literature. There are coalitions of trapezium-trapezoid [20], scaphoidtrapeziumtrapezoid [22], scaphoid-trapezium-trapezoid-capitate [8], scaphoid-lunate-triquetrum [10] and pisiform-hamate [21, 24]. A widened scapholunate joint space, as seen in Case 1, had earlier been described by Metz et al. [12]. Although, all these patients had a congenital lunotriquetral coalition. It is important in patients with a coalition that cross the carpal rows to check if associated abnormalities are present because these synostosis are often part of a syndrome.
Treatment can be either conservative or operative, which depends on symptoms of the patient and the radiological type (incomplete, partial of complete coalition) [17,21]. Conservative treatment consists of elevation, relative rest or immobilisation, anti-inflammatory medication, cast immobilization and elimination of activities that precipitate pain [9,10,14,17,23]. If operative treatment is needed, a (partial) arthrodesis can be performed [22]. In tarsal coalitions, (arthroscopic) resection of the barr with or without interposition of material has been described [25,26]. In the wrist however, this has, to our knowledge, never been described.