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Arthrographic surface anatomy of the carpal triangular fibrocartilage complex
Arthrographic surface anatomy of the carpal triangular fibrocartilage complex In a review of 364 radiocarpal and 123 distal radio&tar joint arthrograms we identified 44 (12%) patients with contrast defects at either the proximal or distal surface of the carpal triangular librocartiiage complex (TFCC). Differences in their arthrographic characteristics distinguished two separategroups of patients; one with similar and another with dissimilar appearing TFCC surface contrast coikctions. Thirty-one of our 44 patients had similar appearing, isolated radial-sided collections at either the proximal or distal TFCC surfaces. Our arthrographic, demographic, and historical study of these patients suggests that the coikctions are not caused by traumatic partial TFCC tears but represent a normal anatomic variant, probably a synovial recess at the radial TFCC attachment. Arthrography and dissection of a limited number of cadaveric specimens confirmed this conclusion. The second group included the remaining 13 patients. This group had contrast collections at either the proximal or distal TFCC surface, which varied in location and appearance. This smaller group is more likely to represent those uncommon patients with partial TFCC defects caused by tears. (J HAND SURG 1988;13A:823-9.)
David C. Hardy, MD, William G. Totty, MD, Kenneth M. Carries, BS, Michael Kyriakos, MD, Paul G. Pin, MD, William R. Reinus, MD, Paul M. Weeks, MD, and Louis A. Gilula, MD, St. Louis, Mu.
D
efinition of normal anatomy and of common variations in the region of the carpal triangular fibrocartilage complex (TFCC) and distal radioulnar joint (DRUJ) is important inasmuch as these structures are increasingly investigated as a potential source of significant wrist disability. Arthrography is often included,in the analysis of patients with suspected carnal problems. Recent studies document increased diagnostic yield when separate injections are made into the various carpal compartments.’ Increased surgical interest in the DRUJ and TFCC mandate description of accurate arthrographic anatomy of this important area. From the Mallinckrodt Institute of Radiology, the Department of Anatomy and Neurobiology, the Department of Pathology, the Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO., and the Department of Radiology, St. Joseph’s Hospital, Kirkwood, MO. Received for publication March 11, 1988.
Jan.
12, 1988; accepted
in revised form
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: William G. Totty, MD, Mallinckrodt Institute of Radiology, 510 S. Kingshighway Blvd, St. Louis, MO 63110.
In a series of radiocarpal and DRUJ arthrograms, we discovered many patients with contrast collections at the proximal or distal TFCC surfaces that did not extend entirely through the substance of the structure.*~3 Previous illustrations of these findings describe them as “partial tears” of the TFCC, but no surgical or anatomic correlation is noted in the texts.4z5 We reviewed our series of radiocarpal and DRUJ arthrograms to ascertain the prevalence of these collections at the time of wrist arthrography and to correlate their presence -with the eventual clinical outcome. Radiocarpal and DRUJ arthrograms were also done on several cadaveric wrists to identify similar defects and to correlate their radiologic and histopathologic appearance . Materials
and methods
Our technique for evaluation of the radiocarpal joint and the DRUJ, including carpal instability series and arthrography, has been described previously.‘, 3.6 We did 364 radiocarpal arthrograms between March 1981 and September 1987. Of these, 123 had additional DRUJ injections. Three hundred two of these cases (83 with additional DRUJ injections) were done before June 1986 when no special films of the TFCC surface were THEJOURNALOFHANDSURGERY
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Fig. 1. Distal TFCC collections. A, Group I-A. Shallow, broad-based collection (arrow) closely paralleling the radial cortex. B, Group II-A. Poorly defined, small contrast collection (arrow) separated from the radius by a greater distance than example A.
exposed. During this period we retrospectively identified several patients with collections at either the proximal or distal TFCC surfaces (Figs. 1 and 2). After June 1986, we altered our technique to include multiple oblique projections of the TFCC surfaces to better evaluate the surface anatomy. A total of 62 additional radiocarpal studies were done during this 16-month period, including 40 DRUJ injections. Distal collections were noted when proximally oriented contrast interrupted the expected smooth, continuous concavity of the radiocarpal contrast at the TFCC surface (Fig. 1). Proximal TFCC surface collections were identified when the normal smooth, curvilinear convexity of the distal aspect of the DRUJ was interrupted by distally directed contrast (Fig. 2). The prevalence of this finding at the time of arthrography during the entire study period, as well as for those examined during the period of intensive study, was calculated. The location, size, and shape of the collections were studied in an attempt to identify separate groups of patients. Clinical and surgical followup of affected patients was obtained when possible. To further investigate these collections we did radiocarpal joint and DRUJ arthrograms on 14 cadaveric
wrist specimens from 13 patients. Seven specimens were frozen and seven were fixed in formalin. After arthrography, the specimens displaying partial TFCC contrast collections were dissected in an attempt to define the anatomic or pathologic basis for the finding. Histologic study of the positive frozen specimens was impossible because of tissue decomposition, but a formalin-fixed specimen with distal and proximal surface TFCC contrast collections was decalcified, embedded in paraffin, and studied by hematoxylin and eosin sections.
Results Wrist arthrograms The demographic features of our patient groups are detailed in Chart 1. Forty-four (12%) of 364 patients had collections at either the distal or proximal TFCC surface (Figs. 1 and 2). Of these 44 patients, 22 (50%) had collections at the distal TFCC surface that were discovered at radiocarpal arthrography (Fig. 1). The overall prevalence of this finding in our group of 364 patients was thus 6% (Chart 1; group I-A, group II-A). We found collections at the proximal TFCC surface in 27 of 123 patients who had DRUJ arthrography (Fig.
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Fig. 2. Proximal TFCC collections. A, Group I-B. Typical contrast collection (arrow) that parallels the radial cortex and is separated from the subchondral cortex by the cartilage thickness. B, Group II-B. Broad-based contrast collection (arrow) separated from the radius by more than the thickness of the distal radial cartilage and oriented differently from the subchondral cortex. 2). The prevalence of this finding in these 123 patients was 22% or 7% of our total patient population (Chart 1; group I-B, group II-B). Five of our 44 patients (11%) had collections at both the distal and the proximal TFCC surfaces. Half of the patients with partial TFCC collections were men. The patients ranged in age from 15 to 56 years, with an average age of 31 years. Analysis of the location, size, and shape of the collections at both the proximal and distal TFCC surfaces identified two distinct patient groups, one with similar and the other with dissimilar TFCC collections. Group I: Similar TFCC recesses. Thirty-one patients (group I) were distinguished by the presence of remarkably similar appearing collections that occurred either proximally, distally, or both proximally and distally at the radial TFCC attachment and exactly paralleled radial cortical bone. There were five patients with both proximal and distal TFCC collections. The collections were uniformly smooth and sharply defined without evidence of hazy “imbibition” of contrast material (Fig. 1, A and Fig. 2, A). The prevalence of this type of collection among all of our patients was 9% (3 1 of 364 patients, Chart 1). Two patients in this group
were lost to follow-up. Twenty-five (81%) of 3 1 were treated conservatively, and four were treated surgically as detailed below. Group I-A: Similar distal TFCC recesses. The collections at the distal TFCC surface in group I displayed a particularly consistent arthrographic appearance (Fig. 1, A). They were sharp in outline and precisely paralleled the closely adjacent radial cortical margin. The depth of the collection varied slightly; some were shallow and others were deep. The collections were at the dorsal lip of the radial sigmoid notch and were often only visible in radial deviation. Thus perhaps only one or two spot films might show the collection. The prevalence of this type of distal TFCC collection was 5% (20 of 364 patients, Chart 1). Only three (15%) had other abnormalities at wrist arthrography (lunotriquetral tears in all three cases). One case in this group was lost to clinical follow-up. Eighteen (95%) of 19 cases were treated conservatively. One patient had triscaphoid fusion (the TFCC was not examined at operation) . Group I-B: Similar proximal TFCC recesses. Similar proximal TFCC surface collections often led to the deepest portion of the radial sigmoid notch. As at the
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Chart
1. Subjects with partial TFCC contrast collections
distal TFCC, the collections were either broad or narrow, but always exactly paralleled the radial cortex. The collections were uniformly sharp and smooth in outline (Fig. 2, A). The prevalence of similar proximal TFCC recesses (group I-B) was 4% (16 of 364 patients) among all patients with wrist arthrograms but was 13% among those who had DRUJ arthrography (Chart 1). One patient in this group was lost to clinical follow-up. Twelve (80%) of the remaining 15 patients were treatei conservatively. Three patients - 19% (all with normal arthrograms except for the TFCC collection) were treated surgically. One patient had an operation for treatment of stenosing tenosynovitis and two had carpal fusions (the TFCC was not examined at operation in these cases). Group II: Dissimilar TFCC defects. Thirteen patients had contrast collections that varied in appearance (overall prevalence, 4%). Their wrist arthrograms were characterized by collections that were dissimilar and could be found anywhere along the TFCC surface. The collections were often jagged or oblique in their course and were usually hazy in appearance, consistent with contrast imbibition in a damaged articular surface (Fig. 1, B and Fig. 2, B). Five (38%) of these 13 patients showed six intra-
The Journal of HAND SURGERY
carpal ligamentous disruptions (scapholunate or lunotriquetral disruption in two patients each, one patient with both scapholunate and lunotriquetral ligamentous disruption). One was lost to clinical follow-up. Four of the remaining 12 patients in this group were treated conservatively. Eight (67%) patients were treated surgically, as detailed below. Group II-A: Dissimilar distal TFCC defects. Only two patients (one male and one female) in group II had collections at the distal TFCC surface (Chart 1). The collections in group II-A showed hazy, indistinct margins, and an oblique orientation. No spatial relationship with the radial TFCC attachment was apparent in these patients (Fig. 1, B). One collection was at the ulnar and one at the radial TFCC aspect. One patient was lost to clinical followup. The other had nonsurgical, conservative therapy. Group II-B: Dissimilar proximal TFCC defects. The dissimilar collections at the proximal TFCC surface (group II-B) were also diverse in appearance. They shared a hazy appearing margin along with an oblique or jagged course at the TFCC but showed marked variation in position with respect to the radial TFCC attachment (Fig. 2, B). Three collections were at the ulnar TFCC aspect, four at the radial aspect, and six in the middle of the TFCC articular surface. Two patients had collections at both the radial and ulnar aspect of the TFCC. Other arthrographic abnormalities were present in nearly half (45%) of this group. Three of the eleven patients were treated conservatively, and the other eight (73%) (including four of the five patients with associated arthrographic abnormalities) had operations. Two patients had direct operative evaluation of the TFCC. One patient had a diffusely frayed TFCC, and the second was found to have a detached ulnar TFCC insertion. Four patients had carpal fusions without operative examination of the TFCC. One patient had surgical decompression of the median nerve, and one had a tendon repair (the TFCC was not examined at operation in these two patients). TFCC collection prevalence during period of intensive study. Seventeen (27%) of 62 patients who had wrist arthrography during the period of intensive study of this finding between June 1986 and September 1987 had collections at the proximal or distal surface of the triangular fibrocartilage. Thus, nearly half (38%) of the 44 patients with TFCC contrast collections in our study were discovered during the 16 months when spot films were exposed specifically to identify such findings. All 17 of the collections discovered during this 16-month period were included in group I (similar TFCC recesses) making its prevalence during this period 27% (17 of 62
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Fig. 3. Cadaveric study. A, Arthrogram. Oblique radiograph of cadaver arthrogram with group I-A distal TFCC contrast collection. B, Histology, X 14 magnification. Hematoxylin and eosin preparation of the radial TFCC (T) attachment showing intact overlying synovium. A small recess (arrows) is seen along the distal surface that may correspond to the contrast collection seen in A. (rc, Radiocarpal joint; dru, distal radioulnar joint.)
patients). Eight (13%) of 62 patients had similar appearing distal TFCC collections (group I-A). Similar appearing proximal TFCC surface collections (group I-B) were present in nine of 40 patients (23%) who had DRUJ arthrography. None of these patients had collections at both the proximal and distal TFCC surface.
Cadaveric study In our group of 14 cadaveric specimens, all of which had injection of both the DRUJ and radiocarpal joint, there were three specimens with four TFCC surface collections (2 1%) . All of these collections showed similar arthrographic characteristics typical of our group I subjects. We did not identify any examples of group II collections among our cadaveric specimens. Three collections involved the distal (2 1%) and one the proximal TFCC surface (7%). Careful anatomic dissection of the positive specimens was done in an effort to correlate the arthrographic findings with the appropriate regional anatomy or with a pathologic abnormality. No evidence of a disruption in the TFCC substance, either partial or complete was identified on either the proximal or distal TFCC surface. Histologic examination of a single formalin-fixed specimen showed a small, synovium-covered recess on the distal TFCC surface correlating with the arthrographic abnormality at this site (Fig. 3). No evidence of inflammatory or fibrotic reaction was noted in the region of the recess. The proximal TFCC surface was normal.
Discussion Arthrographically demonstrable TFCC contrast collections (groups I and II combined) occurred in 44 (12%) of our total of 364 wrist arthrograms. During the period when we searched intensively for these collections the prevalence was 27%. The prevalence of group I collections was 9% overall but was 27% during the period of intensive study. The prevalence of group II collections, however, was much smaller (4%). None were discovered during the period of intensive study, confirming their infrequent occurrence. We believe that the prevalence found during the period of intensive study is the most accurate. We believe this to be so because we found that, in most cases, the finding was visible only on a limited number of films and that proper wrist positioning was essential to identification of the contrast collection. This was especially true in identifying the subgroup with similar distal TFCC collections (group I-A). Positioning the wrist in a slight obliquity from the frontal position with radial deviation seemed to be the best way to reproduce the finding in many cases. This sensitivity to projection and position may explain why these collections have only recently been described by arthrographers who were carefully searching for TFCC abnormalities.“4 Our belief that the finding is common is further reinforced by the 21% cadaveric prevalence we discovered. Croups I and II are distinguished not only by the differing arthrographic appearance of their TFCC col-
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Hardy et af.
lections but also by differences in several clinical parameters. Those who have similar TFCC recesses (group I) are slightly younger (age 31 versus 33), more commonly women (58% versus 31%), more often display ulnar minus variance (35% versus O%), and less commonly have other arthrographic abnormalities (16% versus 38%) when compared with group II patients with dissimilar TFCC defects. Most patients in group I (8 1%) were treated conservatively, and two thirds of those in group II had an operation. The two group II patients who had surgical evaluation of the region both were confirmed to have abnormalities of this important structure. We believe that these patients are those who have traumatic partial tears of the TFCC substance. For this reason we identify group II patients as those with dissimilar TFCC defects. We believe that patients in group I manifest an anatomic variation in the TFCC attachment and not a partial TFCC tear. Accordingly, we believe that these collections are best characterized as similar TFCC recesses. Histologic identification of a small recess at the distal TFCC surface without associated inflammatory or fibrotic changes correlates the arthrographic findings with the anatomy of the region. Although one might argue that the small collection at the distal TFCC surface on our histologic specimen might be an artifact after death, intact synovium overlying the TFCC recess suggests that this is not the case. We were unable to identify an anatomic or histologic correlate for group I-B collections. The fact that the proximal TFCC surface appeared normal on gross and histologic inspection suggests that this too is an anatomic variant, perhaps a recess. Because group I-B proximal contrast collections were more often broad and rounded in configuration they might be less obvious to gross anatomic or histologic inspection. Group I recesses can be differentiated from group II defects by several criteria: (1) The position of the recesses closely adjacent to the radial sigmoid notch is not present in most traumatic group II TFCC defects. It seems reasonable to assume that sporadic cases of true partial surface TFCC group II defects may occur adjacent to the radial cortex. Thus, differentiation of group II TFCC defects from group 1 recesses should be based on more than collection position; (2) group I recesses have smooth, sharply defined borders. Group II defects have indistinct margins, “imbibe” contrast, and thus have a hazy outline; (3) group II defects often have an oblique or jagged course different from the short, straight course parallel to the cortex of the radial sigmoid notch seen with group I recesses; (4) The group I recesses we describe are often a transient phenomenon, visible in only one projection, and with the wrist in only one of several positions. Pathologic group II
defects are visible on multiple spot films and are usually not as dependent on wrist position; (5) In most cases, patients with anatomic recesses have normal wrist ar thrograms, and those with traumatic defects often have other artbrographic abnormalities; and (6) Two thirds of patients with proximal TFCC recesses (group I-B) display negative ulnar variance. The prevalence of negative ulnar variance is not increased in association with other collections. In a previous study we found that the majority of our complete TFCC communications were radial sided. ’ Most of the complete TFCC communications in our collection were not intimately related to the radial cortex, as were the group I collections we ascribe to anatomic variation. Three complete TFCC communications in our file, however, have a course immediately adjacent to the radial cortex. This type of complete TFCC communication is uncommon, representing only 2% of our complete TFCC communications. These three complete TFCC communications at the radial TFCC attachment could be explained if the group I collections we believe are anatomic variants were, in fact, partial TFCC tears that later progress to completion. Alternatively, group I collections could represent a localized congenital TFCC recess or thinning predisposing some patients to traumatic TFCC disruption under stressful conditions. We are in favor of the second conclusion on the basis of the frequency of group I collections, on our anatomic analysis of patients with the finding, and on the clinical and historical factors that are cited above. Small collections of contrast partially projecting over the radial aspect of the TFCC may be discovered in approximately one in four patients who have carpal arthrography. Collections may be found at the proximal TFCC surface at DRUJ arthrography in one in four studies, while collections at the distal TFCC will be present in one in 10 patients undergoing radiocarpal arthrography. The collections, when typical in position and configuration, probably represent an anatomic recess at the radial TFCC attachment and do not necessarily represent a partial tear of the meniscal complex. Patients with dissimilar appearing TFCC defects are uncommon, occurring in about one in 20 patients examined by wrist arthrography. We believe that these defects are caused by traumatic partial TFCC tears. They are most commonly found in association with other arthrographic abnormalities and are most common at the proximal TFCC surface.
REFERENCES 1. Levinsohn EM, Palmer AK, Coren AB, Zinberg E. Wrist
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arthrography: the value of the three compartment injection technique. Skeletal Radio1 1987;16:539-44. 2. Reinus WR, Hardy DC, Totty WG, Gilula LA. Arthographic evaluation of the carpal triangular fibrocartilage complex. J HANDSURG 1987;12A:495-503.
3. Gilula LA, Hardy DC, Totty WG. Distal radioulnar joint arthrography. AJR 1988;150:864-6. 4. Goldman AB. Wrist arthrography. In: Goldman AB, ed.
Arthrographic surface anatomy of TFCC
Procedures in skeletal radiology. New York: Grune & Stratton, 1984:360-l. 5. Ficat RP, Philippe J. The wrist. In: Ficat RP, Philippe J, eds. Contrast arthrography of the synovial joints. New York: Masson Publishing, 1981:148. 6. Gilula LA, Destouet JM, Weeks PM, Young LV, Wray
RC. Roentgenographic diagnosis of the painful wrist. Clin Orthop 1984;187:52-64.
Anomalous muscles of the first dorsal compartment of the wrist _ Exertion-induced pain and swelling in the distal forearm and radial aspect of the wrist were seen in two patients. Exploration revealed an anomalous muscle belly extending into the iirst dorsal compartment in both cases-an anomaly that we believe has not been previously reported. Surgical release of the compartment resulted in complete relief of pain in both patients. (J HAND SURG 1988;13A:829-31.)
Mukund R. Patel, MD, and Shekhar S. Desai, MD, Brooklyn, N.Y.
T
wo patients seen initially with symptoms suggestive of de Quervain’s tenosynovitis are reported. On exploration the muscle belly of the extensor pollicis brevis in one patient and the muscle belly of abductor pollicis longus in the second patient were found to extend into the first dorsal compartment of the wrist. In both patients, the muscle bellies remained in the compartment on radial deviation of the wrist and extended further into the compartment on ulnar deviation of the wrist. To the best of our knowledge the extension of an anomalous muscle belly into the first dorsal compartment has not been previously reported. M
From the Division of Orthopedic Surgery, Maimonides Medical Center, Brooklyn, N.Y. Received for publication July 20, 1987; accepted in revised form Jan. 16, 1988. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: M. R. Patel, MD, 4901 Fort Hamilton Pkwy, Brooklyn, NY 11219.
Case reports Case 1. A 43-year-old right-handed female secretary was seen initially with complaints of gradually increasing pain and swelling over the dorsal and radial side of the right distal forearm of 1 years’ duration. The pain was typically aggravated by strenuous bowling and was relieved by rest. Physical examination showed that she had fullness of the radial side of the wrist extending into the dorsal distal forearm. The swelling was soft in consistency and had mediolateral mobility. Results of the Finkelstein test’ were negative on ulnar deviation of the wrist with or without thumb adduction. Surgical exploration through a longitudinal incision centered over the swelling revealed a hypertrophic muscle belly of abductor pollicis longus. The muscle belly extended into the first dorsal compartment under the extensor retinaculum. In neutral position of the wrist the muscle fibers were within the compartment and on ulnar deviation the muscle belly was found to squeeze into the rigid confines of the first dorsal compartment. The fibrous roof of the compartment was released until the muscle belly mass was free of any compression throughout its full excursion. On incising the roof the muscle belly was seen to bulge out of the dorsal compartment. The tendons of the abductor pollicis longus and the extensor pollicis brevis were found within the same tunnel. There was no visible evidence of tenosynovitis or an aberrant tendon.
THEJOURNAL OF HANDSURGERY 829
David C. Hardy, MD, William G. Totty, MD, Kenneth M. Carries, BS, Michael Kyriakos, MD, Paul G. Pin, MD, William R. Reinus, MD, Paul M. Weeks, MD, and Louis A. Gilula, MD, St. Louis, Mu.
D
efinition of normal anatomy and of common variations in the region of the carpal triangular fibrocartilage complex (TFCC) and distal radioulnar joint (DRUJ) is important inasmuch as these structures are increasingly investigated as a potential source of significant wrist disability. Arthrography is often included,in the analysis of patients with suspected carnal problems. Recent studies document increased diagnostic yield when separate injections are made into the various carpal compartments.’ Increased surgical interest in the DRUJ and TFCC mandate description of accurate arthrographic anatomy of this important area. From the Mallinckrodt Institute of Radiology, the Department of Anatomy and Neurobiology, the Department of Pathology, the Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO., and the Department of Radiology, St. Joseph’s Hospital, Kirkwood, MO. Received for publication March 11, 1988.
Jan.
12, 1988; accepted
in revised form
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: William G. Totty, MD, Mallinckrodt Institute of Radiology, 510 S. Kingshighway Blvd, St. Louis, MO 63110.
In a series of radiocarpal and DRUJ arthrograms, we discovered many patients with contrast collections at the proximal or distal TFCC surfaces that did not extend entirely through the substance of the structure.*~3 Previous illustrations of these findings describe them as “partial tears” of the TFCC, but no surgical or anatomic correlation is noted in the texts.4z5 We reviewed our series of radiocarpal and DRUJ arthrograms to ascertain the prevalence of these collections at the time of wrist arthrography and to correlate their presence -with the eventual clinical outcome. Radiocarpal and DRUJ arthrograms were also done on several cadaveric wrists to identify similar defects and to correlate their radiologic and histopathologic appearance . Materials
and methods
Our technique for evaluation of the radiocarpal joint and the DRUJ, including carpal instability series and arthrography, has been described previously.‘, 3.6 We did 364 radiocarpal arthrograms between March 1981 and September 1987. Of these, 123 had additional DRUJ injections. Three hundred two of these cases (83 with additional DRUJ injections) were done before June 1986 when no special films of the TFCC surface were THEJOURNALOFHANDSURGERY
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Fig. 1. Distal TFCC collections. A, Group I-A. Shallow, broad-based collection (arrow) closely paralleling the radial cortex. B, Group II-A. Poorly defined, small contrast collection (arrow) separated from the radius by a greater distance than example A.
exposed. During this period we retrospectively identified several patients with collections at either the proximal or distal TFCC surfaces (Figs. 1 and 2). After June 1986, we altered our technique to include multiple oblique projections of the TFCC surfaces to better evaluate the surface anatomy. A total of 62 additional radiocarpal studies were done during this 16-month period, including 40 DRUJ injections. Distal collections were noted when proximally oriented contrast interrupted the expected smooth, continuous concavity of the radiocarpal contrast at the TFCC surface (Fig. 1). Proximal TFCC surface collections were identified when the normal smooth, curvilinear convexity of the distal aspect of the DRUJ was interrupted by distally directed contrast (Fig. 2). The prevalence of this finding at the time of arthrography during the entire study period, as well as for those examined during the period of intensive study, was calculated. The location, size, and shape of the collections were studied in an attempt to identify separate groups of patients. Clinical and surgical followup of affected patients was obtained when possible. To further investigate these collections we did radiocarpal joint and DRUJ arthrograms on 14 cadaveric
wrist specimens from 13 patients. Seven specimens were frozen and seven were fixed in formalin. After arthrography, the specimens displaying partial TFCC contrast collections were dissected in an attempt to define the anatomic or pathologic basis for the finding. Histologic study of the positive frozen specimens was impossible because of tissue decomposition, but a formalin-fixed specimen with distal and proximal surface TFCC contrast collections was decalcified, embedded in paraffin, and studied by hematoxylin and eosin sections.
Results Wrist arthrograms The demographic features of our patient groups are detailed in Chart 1. Forty-four (12%) of 364 patients had collections at either the distal or proximal TFCC surface (Figs. 1 and 2). Of these 44 patients, 22 (50%) had collections at the distal TFCC surface that were discovered at radiocarpal arthrography (Fig. 1). The overall prevalence of this finding in our group of 364 patients was thus 6% (Chart 1; group I-A, group II-A). We found collections at the proximal TFCC surface in 27 of 123 patients who had DRUJ arthrography (Fig.
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Fig. 2. Proximal TFCC collections. A, Group I-B. Typical contrast collection (arrow) that parallels the radial cortex and is separated from the subchondral cortex by the cartilage thickness. B, Group II-B. Broad-based contrast collection (arrow) separated from the radius by more than the thickness of the distal radial cartilage and oriented differently from the subchondral cortex. 2). The prevalence of this finding in these 123 patients was 22% or 7% of our total patient population (Chart 1; group I-B, group II-B). Five of our 44 patients (11%) had collections at both the distal and the proximal TFCC surfaces. Half of the patients with partial TFCC collections were men. The patients ranged in age from 15 to 56 years, with an average age of 31 years. Analysis of the location, size, and shape of the collections at both the proximal and distal TFCC surfaces identified two distinct patient groups, one with similar and the other with dissimilar TFCC collections. Group I: Similar TFCC recesses. Thirty-one patients (group I) were distinguished by the presence of remarkably similar appearing collections that occurred either proximally, distally, or both proximally and distally at the radial TFCC attachment and exactly paralleled radial cortical bone. There were five patients with both proximal and distal TFCC collections. The collections were uniformly smooth and sharply defined without evidence of hazy “imbibition” of contrast material (Fig. 1, A and Fig. 2, A). The prevalence of this type of collection among all of our patients was 9% (3 1 of 364 patients, Chart 1). Two patients in this group
were lost to follow-up. Twenty-five (81%) of 3 1 were treated conservatively, and four were treated surgically as detailed below. Group I-A: Similar distal TFCC recesses. The collections at the distal TFCC surface in group I displayed a particularly consistent arthrographic appearance (Fig. 1, A). They were sharp in outline and precisely paralleled the closely adjacent radial cortical margin. The depth of the collection varied slightly; some were shallow and others were deep. The collections were at the dorsal lip of the radial sigmoid notch and were often only visible in radial deviation. Thus perhaps only one or two spot films might show the collection. The prevalence of this type of distal TFCC collection was 5% (20 of 364 patients, Chart 1). Only three (15%) had other abnormalities at wrist arthrography (lunotriquetral tears in all three cases). One case in this group was lost to clinical follow-up. Eighteen (95%) of 19 cases were treated conservatively. One patient had triscaphoid fusion (the TFCC was not examined at operation) . Group I-B: Similar proximal TFCC recesses. Similar proximal TFCC surface collections often led to the deepest portion of the radial sigmoid notch. As at the
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Chart
1. Subjects with partial TFCC contrast collections
distal TFCC, the collections were either broad or narrow, but always exactly paralleled the radial cortex. The collections were uniformly sharp and smooth in outline (Fig. 2, A). The prevalence of similar proximal TFCC recesses (group I-B) was 4% (16 of 364 patients) among all patients with wrist arthrograms but was 13% among those who had DRUJ arthrography (Chart 1). One patient in this group was lost to clinical follow-up. Twelve (80%) of the remaining 15 patients were treatei conservatively. Three patients - 19% (all with normal arthrograms except for the TFCC collection) were treated surgically. One patient had an operation for treatment of stenosing tenosynovitis and two had carpal fusions (the TFCC was not examined at operation in these cases). Group II: Dissimilar TFCC defects. Thirteen patients had contrast collections that varied in appearance (overall prevalence, 4%). Their wrist arthrograms were characterized by collections that were dissimilar and could be found anywhere along the TFCC surface. The collections were often jagged or oblique in their course and were usually hazy in appearance, consistent with contrast imbibition in a damaged articular surface (Fig. 1, B and Fig. 2, B). Five (38%) of these 13 patients showed six intra-
The Journal of HAND SURGERY
carpal ligamentous disruptions (scapholunate or lunotriquetral disruption in two patients each, one patient with both scapholunate and lunotriquetral ligamentous disruption). One was lost to clinical follow-up. Four of the remaining 12 patients in this group were treated conservatively. Eight (67%) patients were treated surgically, as detailed below. Group II-A: Dissimilar distal TFCC defects. Only two patients (one male and one female) in group II had collections at the distal TFCC surface (Chart 1). The collections in group II-A showed hazy, indistinct margins, and an oblique orientation. No spatial relationship with the radial TFCC attachment was apparent in these patients (Fig. 1, B). One collection was at the ulnar and one at the radial TFCC aspect. One patient was lost to clinical followup. The other had nonsurgical, conservative therapy. Group II-B: Dissimilar proximal TFCC defects. The dissimilar collections at the proximal TFCC surface (group II-B) were also diverse in appearance. They shared a hazy appearing margin along with an oblique or jagged course at the TFCC but showed marked variation in position with respect to the radial TFCC attachment (Fig. 2, B). Three collections were at the ulnar TFCC aspect, four at the radial aspect, and six in the middle of the TFCC articular surface. Two patients had collections at both the radial and ulnar aspect of the TFCC. Other arthrographic abnormalities were present in nearly half (45%) of this group. Three of the eleven patients were treated conservatively, and the other eight (73%) (including four of the five patients with associated arthrographic abnormalities) had operations. Two patients had direct operative evaluation of the TFCC. One patient had a diffusely frayed TFCC, and the second was found to have a detached ulnar TFCC insertion. Four patients had carpal fusions without operative examination of the TFCC. One patient had surgical decompression of the median nerve, and one had a tendon repair (the TFCC was not examined at operation in these two patients). TFCC collection prevalence during period of intensive study. Seventeen (27%) of 62 patients who had wrist arthrography during the period of intensive study of this finding between June 1986 and September 1987 had collections at the proximal or distal surface of the triangular fibrocartilage. Thus, nearly half (38%) of the 44 patients with TFCC contrast collections in our study were discovered during the 16 months when spot films were exposed specifically to identify such findings. All 17 of the collections discovered during this 16-month period were included in group I (similar TFCC recesses) making its prevalence during this period 27% (17 of 62
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Fig. 3. Cadaveric study. A, Arthrogram. Oblique radiograph of cadaver arthrogram with group I-A distal TFCC contrast collection. B, Histology, X 14 magnification. Hematoxylin and eosin preparation of the radial TFCC (T) attachment showing intact overlying synovium. A small recess (arrows) is seen along the distal surface that may correspond to the contrast collection seen in A. (rc, Radiocarpal joint; dru, distal radioulnar joint.)
patients). Eight (13%) of 62 patients had similar appearing distal TFCC collections (group I-A). Similar appearing proximal TFCC surface collections (group I-B) were present in nine of 40 patients (23%) who had DRUJ arthrography. None of these patients had collections at both the proximal and distal TFCC surface.
Cadaveric study In our group of 14 cadaveric specimens, all of which had injection of both the DRUJ and radiocarpal joint, there were three specimens with four TFCC surface collections (2 1%) . All of these collections showed similar arthrographic characteristics typical of our group I subjects. We did not identify any examples of group II collections among our cadaveric specimens. Three collections involved the distal (2 1%) and one the proximal TFCC surface (7%). Careful anatomic dissection of the positive specimens was done in an effort to correlate the arthrographic findings with the appropriate regional anatomy or with a pathologic abnormality. No evidence of a disruption in the TFCC substance, either partial or complete was identified on either the proximal or distal TFCC surface. Histologic examination of a single formalin-fixed specimen showed a small, synovium-covered recess on the distal TFCC surface correlating with the arthrographic abnormality at this site (Fig. 3). No evidence of inflammatory or fibrotic reaction was noted in the region of the recess. The proximal TFCC surface was normal.
Discussion Arthrographically demonstrable TFCC contrast collections (groups I and II combined) occurred in 44 (12%) of our total of 364 wrist arthrograms. During the period when we searched intensively for these collections the prevalence was 27%. The prevalence of group I collections was 9% overall but was 27% during the period of intensive study. The prevalence of group II collections, however, was much smaller (4%). None were discovered during the period of intensive study, confirming their infrequent occurrence. We believe that the prevalence found during the period of intensive study is the most accurate. We believe this to be so because we found that, in most cases, the finding was visible only on a limited number of films and that proper wrist positioning was essential to identification of the contrast collection. This was especially true in identifying the subgroup with similar distal TFCC collections (group I-A). Positioning the wrist in a slight obliquity from the frontal position with radial deviation seemed to be the best way to reproduce the finding in many cases. This sensitivity to projection and position may explain why these collections have only recently been described by arthrographers who were carefully searching for TFCC abnormalities.“4 Our belief that the finding is common is further reinforced by the 21% cadaveric prevalence we discovered. Croups I and II are distinguished not only by the differing arthrographic appearance of their TFCC col-
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Hardy et af.
lections but also by differences in several clinical parameters. Those who have similar TFCC recesses (group I) are slightly younger (age 31 versus 33), more commonly women (58% versus 31%), more often display ulnar minus variance (35% versus O%), and less commonly have other arthrographic abnormalities (16% versus 38%) when compared with group II patients with dissimilar TFCC defects. Most patients in group I (8 1%) were treated conservatively, and two thirds of those in group II had an operation. The two group II patients who had surgical evaluation of the region both were confirmed to have abnormalities of this important structure. We believe that these patients are those who have traumatic partial tears of the TFCC substance. For this reason we identify group II patients as those with dissimilar TFCC defects. We believe that patients in group I manifest an anatomic variation in the TFCC attachment and not a partial TFCC tear. Accordingly, we believe that these collections are best characterized as similar TFCC recesses. Histologic identification of a small recess at the distal TFCC surface without associated inflammatory or fibrotic changes correlates the arthrographic findings with the anatomy of the region. Although one might argue that the small collection at the distal TFCC surface on our histologic specimen might be an artifact after death, intact synovium overlying the TFCC recess suggests that this is not the case. We were unable to identify an anatomic or histologic correlate for group I-B collections. The fact that the proximal TFCC surface appeared normal on gross and histologic inspection suggests that this too is an anatomic variant, perhaps a recess. Because group I-B proximal contrast collections were more often broad and rounded in configuration they might be less obvious to gross anatomic or histologic inspection. Group I recesses can be differentiated from group II defects by several criteria: (1) The position of the recesses closely adjacent to the radial sigmoid notch is not present in most traumatic group II TFCC defects. It seems reasonable to assume that sporadic cases of true partial surface TFCC group II defects may occur adjacent to the radial cortex. Thus, differentiation of group II TFCC defects from group 1 recesses should be based on more than collection position; (2) group I recesses have smooth, sharply defined borders. Group II defects have indistinct margins, “imbibe” contrast, and thus have a hazy outline; (3) group II defects often have an oblique or jagged course different from the short, straight course parallel to the cortex of the radial sigmoid notch seen with group I recesses; (4) The group I recesses we describe are often a transient phenomenon, visible in only one projection, and with the wrist in only one of several positions. Pathologic group II
defects are visible on multiple spot films and are usually not as dependent on wrist position; (5) In most cases, patients with anatomic recesses have normal wrist ar thrograms, and those with traumatic defects often have other artbrographic abnormalities; and (6) Two thirds of patients with proximal TFCC recesses (group I-B) display negative ulnar variance. The prevalence of negative ulnar variance is not increased in association with other collections. In a previous study we found that the majority of our complete TFCC communications were radial sided. ’ Most of the complete TFCC communications in our collection were not intimately related to the radial cortex, as were the group I collections we ascribe to anatomic variation. Three complete TFCC communications in our file, however, have a course immediately adjacent to the radial cortex. This type of complete TFCC communication is uncommon, representing only 2% of our complete TFCC communications. These three complete TFCC communications at the radial TFCC attachment could be explained if the group I collections we believe are anatomic variants were, in fact, partial TFCC tears that later progress to completion. Alternatively, group I collections could represent a localized congenital TFCC recess or thinning predisposing some patients to traumatic TFCC disruption under stressful conditions. We are in favor of the second conclusion on the basis of the frequency of group I collections, on our anatomic analysis of patients with the finding, and on the clinical and historical factors that are cited above. Small collections of contrast partially projecting over the radial aspect of the TFCC may be discovered in approximately one in four patients who have carpal arthrography. Collections may be found at the proximal TFCC surface at DRUJ arthrography in one in four studies, while collections at the distal TFCC will be present in one in 10 patients undergoing radiocarpal arthrography. The collections, when typical in position and configuration, probably represent an anatomic recess at the radial TFCC attachment and do not necessarily represent a partial tear of the meniscal complex. Patients with dissimilar appearing TFCC defects are uncommon, occurring in about one in 20 patients examined by wrist arthrography. We believe that these defects are caused by traumatic partial TFCC tears. They are most commonly found in association with other arthrographic abnormalities and are most common at the proximal TFCC surface.
REFERENCES 1. Levinsohn EM, Palmer AK, Coren AB, Zinberg E. Wrist
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arthrography: the value of the three compartment injection technique. Skeletal Radio1 1987;16:539-44. 2. Reinus WR, Hardy DC, Totty WG, Gilula LA. Arthographic evaluation of the carpal triangular fibrocartilage complex. J HANDSURG 1987;12A:495-503.
3. Gilula LA, Hardy DC, Totty WG. Distal radioulnar joint arthrography. AJR 1988;150:864-6. 4. Goldman AB. Wrist arthrography. In: Goldman AB, ed.
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Procedures in skeletal radiology. New York: Grune & Stratton, 1984:360-l. 5. Ficat RP, Philippe J. The wrist. In: Ficat RP, Philippe J, eds. Contrast arthrography of the synovial joints. New York: Masson Publishing, 1981:148. 6. Gilula LA, Destouet JM, Weeks PM, Young LV, Wray
RC. Roentgenographic diagnosis of the painful wrist. Clin Orthop 1984;187:52-64.
Anomalous muscles of the first dorsal compartment of the wrist _ Exertion-induced pain and swelling in the distal forearm and radial aspect of the wrist were seen in two patients. Exploration revealed an anomalous muscle belly extending into the iirst dorsal compartment in both cases-an anomaly that we believe has not been previously reported. Surgical release of the compartment resulted in complete relief of pain in both patients. (J HAND SURG 1988;13A:829-31.)
Mukund R. Patel, MD, and Shekhar S. Desai, MD, Brooklyn, N.Y.
T
wo patients seen initially with symptoms suggestive of de Quervain’s tenosynovitis are reported. On exploration the muscle belly of the extensor pollicis brevis in one patient and the muscle belly of abductor pollicis longus in the second patient were found to extend into the first dorsal compartment of the wrist. In both patients, the muscle bellies remained in the compartment on radial deviation of the wrist and extended further into the compartment on ulnar deviation of the wrist. To the best of our knowledge the extension of an anomalous muscle belly into the first dorsal compartment has not been previously reported. M
From the Division of Orthopedic Surgery, Maimonides Medical Center, Brooklyn, N.Y. Received for publication July 20, 1987; accepted in revised form Jan. 16, 1988. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: M. R. Patel, MD, 4901 Fort Hamilton Pkwy, Brooklyn, NY 11219.
Case reports Case 1. A 43-year-old right-handed female secretary was seen initially with complaints of gradually increasing pain and swelling over the dorsal and radial side of the right distal forearm of 1 years’ duration. The pain was typically aggravated by strenuous bowling and was relieved by rest. Physical examination showed that she had fullness of the radial side of the wrist extending into the dorsal distal forearm. The swelling was soft in consistency and had mediolateral mobility. Results of the Finkelstein test’ were negative on ulnar deviation of the wrist with or without thumb adduction. Surgical exploration through a longitudinal incision centered over the swelling revealed a hypertrophic muscle belly of abductor pollicis longus. The muscle belly extended into the first dorsal compartment under the extensor retinaculum. In neutral position of the wrist the muscle fibers were within the compartment and on ulnar deviation the muscle belly was found to squeeze into the rigid confines of the first dorsal compartment. The fibrous roof of the compartment was released until the muscle belly mass was free of any compression throughout its full excursion. On incising the roof the muscle belly was seen to bulge out of the dorsal compartment. The tendons of the abductor pollicis longus and the extensor pollicis brevis were found within the same tunnel. There was no visible evidence of tenosynovitis or an aberrant tendon.
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