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The role of midcarpal arthroscopy in the diagnosis of disorders of the wrist
The Role of Midcarpal Arthroscopy in the Diagnosis of Disorders of the Wrist Eric P. Hofmeister, MD, Khiem D. Dao, MD, San Diego, CA, Keith A. Glowacki, MD, Richmond, VA, CDR Alexander Y. Shin, MD, San Diego, CA The findings of midcarpal versus radiocarpal arthroscopic examinations were compared in the diagnosis of a variety of wrist pathology in 89 patients. During 15 months 89 midcarpal arthroscopic examinations were performed in conjunction with radiocarpal arthroscopic examinations. Eighty-one wrists underwent arthroscopy for acute or chronic intracarpal instability. Eight wrists underwent arthroscopy for arthroscopy-assisted intra-articular distal radius fracture reduction. In the acute wrist instability group midcarpal arthroscopy added to the radiocarpal diagnosis in 21 of 26 (82%) of the wrists. In the chronic wrist instability group midcarpal arthroscopy added to the radiocarpal diagnosis in 46 of 55 (84%) of the wrists. In the distal radius group 5 of 8 wrists had additional pathology on the midcarpal arthroscopy examination, leading to additional surgical intervention. These results demonstrate that midcarpal arthroscopy added statistically significant information to the radiocarpal examination compared with wrist arthroscopy performed without a midcarpal examination. (J Hand Surg 2001;26A:407– 414. Copyright © 2001 by the American Society for Surgery of the Hand.) Key words: Wrist, arthroscopy, diagnosis, midcarpal, radiocarpal.
Arthroscopy of the wrist is currently a widely used modality in the diagnosis and treatment of a wide spectrum of wrist pathology. While arthroscopic techniques and indications continue to evolve, the basic essentials of a comprehensive wrist arthroscopic examination have been suggested but not formally established. Wrist arthroscopists agree that, at
From the Division of Hand and Microsurgery, Department of Orthopaedic Surgery, Naval Medical Center San Diego, San Diego, CA; and Advanced Orthopaedics, Richmond, VA. Received for publication May 19, 2000; accepted in revised form February 21, 2001. The views expressed in this article are those of the authors and do not reflect the official policy of position of the Department of the Navy, Department of Defense, or the United States Government. 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: Alexander Y. Shin, MD, c/o Clinical Investigation Department, Naval Medical Center San Diego, San Diego, CA 92134. Copyright © 2001 by the American Society for Surgery of the Hand 0363-5023/01/26A03-0004$35.00/0 doi:10.1053/jhsu.2001.24973
minimum, a radiocarpal arthroscopic examination is required.1–3 The controversy lies in whether a midcarpal examination is necessary. Earlier wrist arthroscopic studies did not detail or advocate evaluation of the midcarpal joint. Although recent literature implies that midcarpal inspections are requisite for a complete wrist arthroscopy,4 –13 no studies have quantified the additional information gained from subsequent midcarpal arthroscopy following radiocarpal arthroscopy. The purpose of this study is to determine the role of the midcarpal arthroscopy in the evaluation of the wrist and, specifically, to determine what if any additional information can be gained by midcarpal examination performed in combination with radiocarpal arthroscopy over radiocarpal arthroscopy alone.
Materials and Methods Between November 1997 and March 1999, 88 patients with 89 involved wrists underwent wrist arthroscopic examination for diagnostic or therapeuThe Journal of Hand Surgery 407
408 Hofmeister et al / Role of Midcarpal Arthroscopy
tic purposes at our institutions (Naval Medical Center San Diego and Advanced Orthopaedic Center). They were monitored in a prospectively accrued database. Patients were excluded if they had undergone a wrist arthrotomy or arthroscopy of the involved wrist. Sixty-eight men and 20 women with an average age of 32 years (range, 20 –58 years) were included. Eighty-one wrists were evaluated for carpal instability; 8 patients underwent arthroscopyassisted distal radius reduction and internal fixation. Thirty-four wrist conditions were classified as acute (ⱕ3 months) and 55 wrists conditions were classified as chronic (⬎3 months). The senior investigators (A.Y.S., K.A.G., K.D.D.) examined all patients. Radiographs of the affected wrists included posteroanterior, lateral, clenched fist, pronated, and supinated oblique views. Additional studies included 3-phase arthrography in patients with suspected carpal instability, tomography (trispiral or computerized) in patients with fractures or suspected arthrosis, or magnetic resonance imaging. Carpal instability included cases of dissociative, nondissociative, and carpal instability complex.14 Patients with chronic carpal instability who did not respond to nonsurgical treatment (casting, splinting, corticosteroid injections, and nonsteroidal anti-inflammatory medications) were suggested a surgical intervention that included arthroscopy. Patients with acute intra-articular distal radius fractures treated by arthroscopy-assisted reduction and percutaneous fixation were also included. All patients gave informed consent for wrist arthroscopy and the surgical procedure.
Surgical Technique All patients underwent the same technique of wrist arthroscopy. Under general or regional anesthesia, the upper extremity was secured to a custom-made foundation (Custom Surgical Service, Byron, MN) with the Concept traction tower (Linvatec, Largo, FL). Finger traps were placed on the index and middle fingers and 15 lb of longitudinal traction was applied. Under tourniquet control, a 30°, 2.7-mm arthroscope (Linvatec) was used to evaluate the radiocarpal and midcarpal joints. Fluid inflow was through the arthroscope cannula via hand pump control. A standardized 2-mm tip probe (Linvatec) was used in the evaluation of instability. Because radiocarpal arthroscopy is often performed alone without radiocarpal arthroscopy, radiocarpal arthroscopy was performed first. The radiocarpal portals were established at the 3-4 (arthroscope por-
tal), 4-5 (probe/shaver portal), and 6 (outflow cannula) intervals. A systematic evaluation was performed of the distal radius and ulna articular surfaces; proximal surfaces of the scaphoid, lunate, and triquetrum; triangular fibrocartilage complex (TFCC); radiocarpal and ulnocarpal ligaments (radioscaphocapitate, long and short radiolunate, radioscapholunate, ulnotriquetrocapitate and ulnolunate ligaments); and the proximal (membranous) portions of the scapholunate and lunotriquetral interosseous ligaments (Fig. 1). The findings from the radiocarpal wrist arthroscopy were documented on a data collection sheet. A provisional diagnosis based on the findings of radiocarpal arthroscopy was formulated and recorded. The midcarpal arthroscopic portals (midcarpal ulnar and midcarpal radial) were established, with outflow through an 18-gauge needle placed in the triquetrohamate joint if needed. The following structures were systematically evaluated: distal articular surfaces of the scaphoid, lunate, and triquetrum; proximal surfaces of the trapezium, trapezoid, capitate, and hamate; and the scapholunate, lunotriquetral, and capitohamate joints (Fig. 2). Findings from the midcarpal arthroscopy were documented; a provisional diagnosis and treatment plan based on midcarpal arthroscopy alone was recorded. Chondromalacia was graded using a modification of the Outerbridge classification.15,16 Intrinsic ligament instability was graded by the Geissler classification (Table 1).17 TFCC tears were classified by Palmer’s description of TFCC lesions.18 When the findings seen on radiocarpal versus midcarpal arthroscopy were compared, only the structures that could be evaluated on both radiocarpal and midcarpal arthroscopy, either directly or indirectly, were compared. These structures included the stability of scapholunate and lunotriquetral interosseous ligaments. The additional findings obtained from midcarpal arthroscopy that could not be determined by radiocarpal arthroscopy were then determined.
Statistical Analysis Because radiocarpal arthroscopy is often performed alone, the assumption that findings of the radiocarpal examination were complete and accurate was made. Based on this assumption nonparametric statistical tests were used to determine if midcarpal arthroscopic examination altered or added to the radiocarpal examination in terms of diagnoses. Only structures that could be evaluated by both midcarpal and radiocarpal arthroscopy were compared (ie, stability of the scapholunate
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 409
Figure 1. The wrist of a 39-year-old man demonstrating (A) grade 1 laxity of the scapholunate ligament and (B) grade 2 laxity of the lunotriquetral ligament on radiocarpal arthroscopy. S, Scaphoid; L, lunate; T, triquetrum; SL, scapholunate ligament complex.
410 Hofmeister et al / Role of Midcarpal Arthroscopy
Figure 2. The midcarpal arthroscopy revealed (A) grade 3 laxity of the scapholunate ligament and (B) grade 3 laxity of the lunotriquetral ligament. (Figure continues)
and lunotriquetral joints). Patients with acute and chronic injuries were evaluated separately. Demographic characteristics (age, sex, injury type, handedness) of the acute and chronic injury groups were com-
pared using multiple linear regression analysis. Statistical significance was set at ␣ ⱕ 0.05. Statistical analysis was performed using SPSS for Windows (version 6.1; SPSS Inc, Prentice Hill, NJ).
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 411
Figure 2. (Contd) (C) The capitohamate joint shows grade 3 laxity; with easy entrance of the probe. S, Scaphoid; L, lunate; T, triquetrum; C, Capitate; H, hamate.
Results For the 34 wrist conditions classified as acute and 55 wrists conditions classified as chronic, no statistical differences existed with respect to age, gender, or extremity involved (p ⫽ .85). A comparison of the evaluation of stability of the
Table 1. Grading of Ligamentous Laxity Based on the Geissler Classification Grade 1: Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. No incongruency of carpal alignment in midcarpal space. Grade 2: Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. Incongruency or step-off of carpal space. There may be slight gap (less than width of probe) between carpal bones. Grade 3: Incongruency or step-off of carpal alignment as seen from both the radiocarpal and midcarpal space. Probe may be passed through gap between carpal bones. Grade 4: Incongruency or step-off of carpal alignment as seen from both the radiocarpal and midcarpal space. There is gross instability with manipulation. A 2.7-mm arthroscope may be passed through the gap between carpal bones. Data from Geissler et al.17
scapholunate and lunotriquetral joints as evaluated on the radiocarpal and midcarpal side was performed. For acute carpal instability cases, midcarpal arthroscopy confirmed the radiocarpal arthroscopy diagnosis in 5 of 26 (21%) wrists and added to the radiocarpal diagnosis in the remaining 21 of 26 (82%) cases. The difference between findings of midcarpal arthroscopy and radiocarpal arthroscopy in the evaluation of the stability of the scapholunate and lunotriquetral ligaments was statistically significant (p ⬍ .001). For scapholunate findings midcarpal arthroscopy confirmed the radiocarpal findings in 16 cases, showed a higher-grade lesion in 2 cases, and indicated the diagnosis in 8 cases. For lunotriquetral findings midcarpal arthroscopy confirmed the radiocarpal findings in 13 cases and indicated the diagnosis in 13 cases. Additional pathologic conditions seen on midcarpal arthroscopy are listed in Table 2. For chronic carpal instability midcarpal arthroscopy confirmed radiocarpal grading of the degree of instability of the scapholunate and lunotriquetral joints in 9 of 55 (16%) cases and added or increased the grade of instability in 46 of 55 (84%) cases. The difference between midcarpal and radiocarpal arthroscopy evaluation of the stability of the scapholunate and lunotriquetral joint was statistically significant
412 Hofmeister et al / Role of Midcarpal Arthroscopy
Table 2. Additional Information Gained From Midcarpal Arthroscopy: 26 Acute Carpal Instability Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Capitohamate instability23 Scapholunate instability Increase in severity
13 (50) 14 (54) 8 (31) 2 (8)
midcarpal arthroscopy. Furthermore, not one of the midcarpal arthroscopic diagnoses was overgraded.
Complications Only one complication of arthroscopy occurred: a partial laceration to the extensor digitorum communis to the small finger. A slight extension lag was noted and no subsequent treatment was rendered. No infections or nerve injuries related to arthroscopy were noted.
Discussion (p ⬍ .001). For scapholunate findings midcarpal arthroscopy confirmed the radiocarpal findings in 30 cases and made the diagnosis in 25 cases. For lunotriquetral findings midcarpal arthroscopy confirmed the radiocarpal findings in 23 cases and made the diagnosis in 32 cases. Additional findings seen by midcarpal arthroscopy are listed in Table 3. In the 8 distal radius fracture cases 3 scapholunate and lunotriquetral instabilities were identified on the radiocarpal examination and were confirmed and graded concordantly on the midcarpal arthroscopic examination. In the remaining 5 patients additional pathology was detected with the midcarpal arthroscopic examination, resulting in additional surgical treatment (Table 4). There were no patients in whom instability of the scapholunate or lunotriquetral was only seen on radiocarpal arthroscopy. Furthermore, no instability was graded worse on the radiocarpal arthroscopy. Of the 89 cases in this series 75 wrists underwent an arthrotomy exposure as part of the definitive wrist reconstruction (ligamentous repair/reconstruction or partial wrist arthrodesis). This provided an opportunity to confirm the arthroscopic findings. The arthrotomy findings confirmed all diagnoses noted on the
Table 3. Additional Information Gained From Midcarpal Arthroscopy: 55 Chronic Carpal Instability Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Capitohamate instability23 Scapholunate instability Midcarpal attenuation Increase in severity Midcarpal arthrosis
32 (58) 24 (44) 25 (45) 8 (15) 6 (11) 4 (7)
Wrist arthroscopy is an essential diagnostic and therapeutic modality in the treatment of carpal pathology. It is more accurate than noninvasive and minimally invasive diagnostic tests such as magnetic resonance imaging and 3-phase arthrography,1,19 and correlates highly with arthrotomy findings. Earlier studies detailing wrist arthroscopy failed to elaborate the role of a midcarpal examination; later studies are replete with discussions on midcarpal arthroscopic utilization.4 –13 Wrist arthroscopy is well recognized as an important adjunct for the diagnosis and treatment of wrist pathology; however, the role of midcarpal arthroscopy has not been adequately defined. In 1996, De Smet et al2 reported the results of a large group of patients who underwent wrist arthroscopy but they did not discern the role of midcarpal arthroscopy. In contrast, current textbooks of hand surgery have stated “no diagnostic arthroscopy is complete without evaluation of the midcarpal joint.”20 Past studies have tried to look at the utility of midcarpal arthroscopy. Fischer and Sennwald21,22 reported on 2 series of patients undergoing wrist arthroscopy. In both series 50% of carpal instability lesions could be identified on midcarpal arthroscopy. No conclusions regarding the role of midcarpal arthroscopy were made, however, nor was a compari-
Table 4. Additional Information Gained From Midcarpal Arthroscopy: 8 Intraarticular Distal Radius Fracture Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Scapholunate instability Capitohamate instability23 Increase in severity
5 (62) 5 (62) 1 (12) 1 (12)
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 413
son of findings seen on radiocarpal versus midcarpal arthroscopy performed. In the present study, when instability of the scapholunate or lunotriquetral ligament was seen on radiocarpal arthroscopy, it was always seen on midcarpal arthroscopy. The corollary was not true. Additionally, midcarpal evaluation of instability was equal or greater than the instability assessed at the radiocarpal arthroscopy. This study clearly documents the utility of the midcarpal arthroscopic examination. All instabilities of the scapholunate or lunotriquetral ligaments discovered during a radiocarpal examination were verified at the midcarpal examination. The converse was not true, however; the majority of instabilities were not seen on radiocarpal arthroscopy when compared with midcarpal arthroscopy. Moreover, the grading of the ligamentous instability was always equal to or greater on the midcarpal examination. Other advantages of the midcarpal examination include visualization of the scaphoid–trapezoid–trapezium joint, midcarpal extrinsic ligaments, the capitohamate joint,23 and the articular surfaces of the midcarpal bones. Capitohamate instability was recently reported.23 Since this report we have routinely included the evaluation of the stability of the capitohamate joint, and evaluate it similarly to the scapholunate and lunotriquetral ligaments. Arthroscopy performed at the time of treatment of intra-articular distal radius fractures substantially increases the recognition of ligament injury24 –26; in the present study midcarpal arthroscopy further increased this recognition. The surgical technique of midcarpal arthroscopy can be mastered quickly; evaluation of this joint adds little to the operative time. As documented in this series and others,6,27 the morbidity rate is also low. We performed radiocarpal arthroscopy before midcarpal arthroscopy. The findings of radiocarpal arthroscopy may have influenced the findings seen at midcarpal arthroscopy. Although this bias could have been eliminated by performing midcarpal arthroscopy first in half of the cases, the goal of the study was to prove that radiocarpal arthroscopy alone may have missed or undergraded many lesions, because it is often performed alone. We do not advocate that midcarpal arthroscopy be performed without radiocarpal arthroscopy. Additional limitations of this study include the exclusion of a normal subject group. The potential for surgeon bias exists; however, in the cases that underwent arthrotomy the diagnosis was in concordance with the midcarpal findings.
This study clearly demonstrates that midcarpal arthroscopy yields significant information in addition to that found during a radiocarpal examination. This additional information alters the diagnosis and potential subsequent treatment. We believe that a complete wrist arthroscopic examination must include a midcarpal examination in addition to a radiocarpal examination. Wrist arthroscopy performed without a midcarpal examination is an incomplete evaluation of the wrist.
References 1. Cooney WP. Evaluation of chronic wrist pain by arthrography, arthroscopy, and arthrotomy. J Hand Surg 1993; 18A:815– 822. 2. De Smet L, Dauwe D, Fortems Y, Zachee B, Fabry G. The value of wrist arthroscopy: an evaluation of 129 cases. J Hand Surg 1996;21B:210 –212. 3. Metz VM, Schimmerl SM, Gilula LA, Viegas SF, Saffar P. Wide scapholunate joint space in lunotriquetral coalition: a normal variant? Radiology 1993;188:557–559. 4. Bettinger PC, Cooney WP III, Berger RA. Arthroscopic anatomy of the wrist. Orthop Clinic North Am 1995;26:707–719. 5. Cooney WP. The future of arthroscopic surgery in the hand and wrist. Hand Clin 1995;11:97–99. 6. Geissler WB, Freeland AE, Weiss A-PC, et al: Techniques of wrist arthroscopy. J Bone Joint Surg 1999;81A:1184 –1197. 7. Savoie FH III, Grondel RJ. Arthroscopy for carpal instability. Orthop Clin North Am 1995;26:731–738. 8. Terrill RQ. Use of arthroscopy in the evaluation and treatment of chronic wrist pain. Hand Clin 1994;10:593– 603. 9. Toby EB, Poehling GG, Koman AL. Midcarpal arthroscopy. Surg Rounds Orthop 1989:23–27. 10. Viegas SF. Midcarpal arthroscopy: anatomy and portals. Hand Clin 1994;10:577–587. 11. Viegas SF. Midcarpal arthroscopy: anatomy and technique. Arthroscopy 1992;8:385–390. 12. Viegas SF. Arthroscopic assessment of carpal instabilities and ligament injuries. Instr Course Lect 1995;44:151–154. 13. Whipple TL. The role of arthroscopy in the treatment of scapholunate instability. Hand Clin 1995;11:37– 40. 14. Dobyns JH, Cooney WP. Classification of carpal instability. In: Cooney WB, Linscheid RL, Dobyns JH (eds). The wrist: diagnosis and operative treatment. St Louis, MO: Mosby, 1998:490 –500. 15. Outerbridge RE. The etiology of chondromalacia patellae. J Bone Joint Surg 1961;43B:752–757. 16. Outerbridge RE. Further studies on the etiology of chondromalacia patella. J Bone Joint Surg 1964;46B:179 –190. 17. Geissler WB, Freeland AE, Savoie FH, McIntyre LW, Whipple TL. Intracarpal soft-tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg 1996;78A:357–365. 18. Palmer AK. Triangular fibrocartilage complex lesions: a classification. J Hand Surg 1989;14A:594 – 606. 19. Roth JH. Haddad RG. Radiocarpal arthroscopy and arthrography in the diagnosis and of ulnar wrist pain. Arthroscopy 1986;2:234 –243.
414 Hofmeister et al / Role of Midcarpal Arthroscopy 20. Ruch DS, Poeling GG. Wrist arthroscopy: ligament instability. In: Green DP, Hotchkiss RN, Pedersen WC, eds. Green’s operative hand surgery. 4th ed. New York: Churchill Livingstone, 1999:203–206. 21. Fischer VM, Sennwald G. Stellenwert der Arthroskopie in der Diagnostik der karpalen Instabilita¨t. Handchir Mikrochir Plast Chir 1993;25:39 – 41. 22. Fischer M, Sennwald G. Die Arthroskopie in der Diagnostik der karpalen Instabilita¨t. Helv Chir Acta 1992;59:693– 696. 23. Shin AY, Glowacki KA, Bishop AT. Dynamic axial carpal instability: a case report. J Hand Surg 1999;24A: 781–785.
24. Fischer M, Denzler C, Sennwald G. Begleitende karpale Bandla¨sionen bei frischen distalen Radiusfrakturen: arthroskopische Studieu¨ber 54 Fa¨lle. Swiss Surg 1996;2:269 –273. 25. Geissler WB, Freeland AE. Arthroscopically assisted reduction of intraarticular distal radius fractures. Clin Orthop 1996;327:135–146. 26. Richards RS, Bennett JD, Roth JH, Milne K Jr. Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radius fractures. J Hand Surg 1997;22A: 772–776. 27. Whipple TL. Precautions for arthroscopy of the wrist. Arthroscopy 1990;6:3– 4.
Arthroscopy of the wrist is currently a widely used modality in the diagnosis and treatment of a wide spectrum of wrist pathology. While arthroscopic techniques and indications continue to evolve, the basic essentials of a comprehensive wrist arthroscopic examination have been suggested but not formally established. Wrist arthroscopists agree that, at
From the Division of Hand and Microsurgery, Department of Orthopaedic Surgery, Naval Medical Center San Diego, San Diego, CA; and Advanced Orthopaedics, Richmond, VA. Received for publication May 19, 2000; accepted in revised form February 21, 2001. The views expressed in this article are those of the authors and do not reflect the official policy of position of the Department of the Navy, Department of Defense, or the United States Government. 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: Alexander Y. Shin, MD, c/o Clinical Investigation Department, Naval Medical Center San Diego, San Diego, CA 92134. Copyright © 2001 by the American Society for Surgery of the Hand 0363-5023/01/26A03-0004$35.00/0 doi:10.1053/jhsu.2001.24973
minimum, a radiocarpal arthroscopic examination is required.1–3 The controversy lies in whether a midcarpal examination is necessary. Earlier wrist arthroscopic studies did not detail or advocate evaluation of the midcarpal joint. Although recent literature implies that midcarpal inspections are requisite for a complete wrist arthroscopy,4 –13 no studies have quantified the additional information gained from subsequent midcarpal arthroscopy following radiocarpal arthroscopy. The purpose of this study is to determine the role of the midcarpal arthroscopy in the evaluation of the wrist and, specifically, to determine what if any additional information can be gained by midcarpal examination performed in combination with radiocarpal arthroscopy over radiocarpal arthroscopy alone.
Materials and Methods Between November 1997 and March 1999, 88 patients with 89 involved wrists underwent wrist arthroscopic examination for diagnostic or therapeuThe Journal of Hand Surgery 407
408 Hofmeister et al / Role of Midcarpal Arthroscopy
tic purposes at our institutions (Naval Medical Center San Diego and Advanced Orthopaedic Center). They were monitored in a prospectively accrued database. Patients were excluded if they had undergone a wrist arthrotomy or arthroscopy of the involved wrist. Sixty-eight men and 20 women with an average age of 32 years (range, 20 –58 years) were included. Eighty-one wrists were evaluated for carpal instability; 8 patients underwent arthroscopyassisted distal radius reduction and internal fixation. Thirty-four wrist conditions were classified as acute (ⱕ3 months) and 55 wrists conditions were classified as chronic (⬎3 months). The senior investigators (A.Y.S., K.A.G., K.D.D.) examined all patients. Radiographs of the affected wrists included posteroanterior, lateral, clenched fist, pronated, and supinated oblique views. Additional studies included 3-phase arthrography in patients with suspected carpal instability, tomography (trispiral or computerized) in patients with fractures or suspected arthrosis, or magnetic resonance imaging. Carpal instability included cases of dissociative, nondissociative, and carpal instability complex.14 Patients with chronic carpal instability who did not respond to nonsurgical treatment (casting, splinting, corticosteroid injections, and nonsteroidal anti-inflammatory medications) were suggested a surgical intervention that included arthroscopy. Patients with acute intra-articular distal radius fractures treated by arthroscopy-assisted reduction and percutaneous fixation were also included. All patients gave informed consent for wrist arthroscopy and the surgical procedure.
Surgical Technique All patients underwent the same technique of wrist arthroscopy. Under general or regional anesthesia, the upper extremity was secured to a custom-made foundation (Custom Surgical Service, Byron, MN) with the Concept traction tower (Linvatec, Largo, FL). Finger traps were placed on the index and middle fingers and 15 lb of longitudinal traction was applied. Under tourniquet control, a 30°, 2.7-mm arthroscope (Linvatec) was used to evaluate the radiocarpal and midcarpal joints. Fluid inflow was through the arthroscope cannula via hand pump control. A standardized 2-mm tip probe (Linvatec) was used in the evaluation of instability. Because radiocarpal arthroscopy is often performed alone without radiocarpal arthroscopy, radiocarpal arthroscopy was performed first. The radiocarpal portals were established at the 3-4 (arthroscope por-
tal), 4-5 (probe/shaver portal), and 6 (outflow cannula) intervals. A systematic evaluation was performed of the distal radius and ulna articular surfaces; proximal surfaces of the scaphoid, lunate, and triquetrum; triangular fibrocartilage complex (TFCC); radiocarpal and ulnocarpal ligaments (radioscaphocapitate, long and short radiolunate, radioscapholunate, ulnotriquetrocapitate and ulnolunate ligaments); and the proximal (membranous) portions of the scapholunate and lunotriquetral interosseous ligaments (Fig. 1). The findings from the radiocarpal wrist arthroscopy were documented on a data collection sheet. A provisional diagnosis based on the findings of radiocarpal arthroscopy was formulated and recorded. The midcarpal arthroscopic portals (midcarpal ulnar and midcarpal radial) were established, with outflow through an 18-gauge needle placed in the triquetrohamate joint if needed. The following structures were systematically evaluated: distal articular surfaces of the scaphoid, lunate, and triquetrum; proximal surfaces of the trapezium, trapezoid, capitate, and hamate; and the scapholunate, lunotriquetral, and capitohamate joints (Fig. 2). Findings from the midcarpal arthroscopy were documented; a provisional diagnosis and treatment plan based on midcarpal arthroscopy alone was recorded. Chondromalacia was graded using a modification of the Outerbridge classification.15,16 Intrinsic ligament instability was graded by the Geissler classification (Table 1).17 TFCC tears were classified by Palmer’s description of TFCC lesions.18 When the findings seen on radiocarpal versus midcarpal arthroscopy were compared, only the structures that could be evaluated on both radiocarpal and midcarpal arthroscopy, either directly or indirectly, were compared. These structures included the stability of scapholunate and lunotriquetral interosseous ligaments. The additional findings obtained from midcarpal arthroscopy that could not be determined by radiocarpal arthroscopy were then determined.
Statistical Analysis Because radiocarpal arthroscopy is often performed alone, the assumption that findings of the radiocarpal examination were complete and accurate was made. Based on this assumption nonparametric statistical tests were used to determine if midcarpal arthroscopic examination altered or added to the radiocarpal examination in terms of diagnoses. Only structures that could be evaluated by both midcarpal and radiocarpal arthroscopy were compared (ie, stability of the scapholunate
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 409
Figure 1. The wrist of a 39-year-old man demonstrating (A) grade 1 laxity of the scapholunate ligament and (B) grade 2 laxity of the lunotriquetral ligament on radiocarpal arthroscopy. S, Scaphoid; L, lunate; T, triquetrum; SL, scapholunate ligament complex.
410 Hofmeister et al / Role of Midcarpal Arthroscopy
Figure 2. The midcarpal arthroscopy revealed (A) grade 3 laxity of the scapholunate ligament and (B) grade 3 laxity of the lunotriquetral ligament. (Figure continues)
and lunotriquetral joints). Patients with acute and chronic injuries were evaluated separately. Demographic characteristics (age, sex, injury type, handedness) of the acute and chronic injury groups were com-
pared using multiple linear regression analysis. Statistical significance was set at ␣ ⱕ 0.05. Statistical analysis was performed using SPSS for Windows (version 6.1; SPSS Inc, Prentice Hill, NJ).
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 411
Figure 2. (Contd) (C) The capitohamate joint shows grade 3 laxity; with easy entrance of the probe. S, Scaphoid; L, lunate; T, triquetrum; C, Capitate; H, hamate.
Results For the 34 wrist conditions classified as acute and 55 wrists conditions classified as chronic, no statistical differences existed with respect to age, gender, or extremity involved (p ⫽ .85). A comparison of the evaluation of stability of the
Table 1. Grading of Ligamentous Laxity Based on the Geissler Classification Grade 1: Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. No incongruency of carpal alignment in midcarpal space. Grade 2: Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. Incongruency or step-off of carpal space. There may be slight gap (less than width of probe) between carpal bones. Grade 3: Incongruency or step-off of carpal alignment as seen from both the radiocarpal and midcarpal space. Probe may be passed through gap between carpal bones. Grade 4: Incongruency or step-off of carpal alignment as seen from both the radiocarpal and midcarpal space. There is gross instability with manipulation. A 2.7-mm arthroscope may be passed through the gap between carpal bones. Data from Geissler et al.17
scapholunate and lunotriquetral joints as evaluated on the radiocarpal and midcarpal side was performed. For acute carpal instability cases, midcarpal arthroscopy confirmed the radiocarpal arthroscopy diagnosis in 5 of 26 (21%) wrists and added to the radiocarpal diagnosis in the remaining 21 of 26 (82%) cases. The difference between findings of midcarpal arthroscopy and radiocarpal arthroscopy in the evaluation of the stability of the scapholunate and lunotriquetral ligaments was statistically significant (p ⬍ .001). For scapholunate findings midcarpal arthroscopy confirmed the radiocarpal findings in 16 cases, showed a higher-grade lesion in 2 cases, and indicated the diagnosis in 8 cases. For lunotriquetral findings midcarpal arthroscopy confirmed the radiocarpal findings in 13 cases and indicated the diagnosis in 13 cases. Additional pathologic conditions seen on midcarpal arthroscopy are listed in Table 2. For chronic carpal instability midcarpal arthroscopy confirmed radiocarpal grading of the degree of instability of the scapholunate and lunotriquetral joints in 9 of 55 (16%) cases and added or increased the grade of instability in 46 of 55 (84%) cases. The difference between midcarpal and radiocarpal arthroscopy evaluation of the stability of the scapholunate and lunotriquetral joint was statistically significant
412 Hofmeister et al / Role of Midcarpal Arthroscopy
Table 2. Additional Information Gained From Midcarpal Arthroscopy: 26 Acute Carpal Instability Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Capitohamate instability23 Scapholunate instability Increase in severity
13 (50) 14 (54) 8 (31) 2 (8)
midcarpal arthroscopy. Furthermore, not one of the midcarpal arthroscopic diagnoses was overgraded.
Complications Only one complication of arthroscopy occurred: a partial laceration to the extensor digitorum communis to the small finger. A slight extension lag was noted and no subsequent treatment was rendered. No infections or nerve injuries related to arthroscopy were noted.
Discussion (p ⬍ .001). For scapholunate findings midcarpal arthroscopy confirmed the radiocarpal findings in 30 cases and made the diagnosis in 25 cases. For lunotriquetral findings midcarpal arthroscopy confirmed the radiocarpal findings in 23 cases and made the diagnosis in 32 cases. Additional findings seen by midcarpal arthroscopy are listed in Table 3. In the 8 distal radius fracture cases 3 scapholunate and lunotriquetral instabilities were identified on the radiocarpal examination and were confirmed and graded concordantly on the midcarpal arthroscopic examination. In the remaining 5 patients additional pathology was detected with the midcarpal arthroscopic examination, resulting in additional surgical treatment (Table 4). There were no patients in whom instability of the scapholunate or lunotriquetral was only seen on radiocarpal arthroscopy. Furthermore, no instability was graded worse on the radiocarpal arthroscopy. Of the 89 cases in this series 75 wrists underwent an arthrotomy exposure as part of the definitive wrist reconstruction (ligamentous repair/reconstruction or partial wrist arthrodesis). This provided an opportunity to confirm the arthroscopic findings. The arthrotomy findings confirmed all diagnoses noted on the
Table 3. Additional Information Gained From Midcarpal Arthroscopy: 55 Chronic Carpal Instability Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Capitohamate instability23 Scapholunate instability Midcarpal attenuation Increase in severity Midcarpal arthrosis
32 (58) 24 (44) 25 (45) 8 (15) 6 (11) 4 (7)
Wrist arthroscopy is an essential diagnostic and therapeutic modality in the treatment of carpal pathology. It is more accurate than noninvasive and minimally invasive diagnostic tests such as magnetic resonance imaging and 3-phase arthrography,1,19 and correlates highly with arthrotomy findings. Earlier studies detailing wrist arthroscopy failed to elaborate the role of a midcarpal examination; later studies are replete with discussions on midcarpal arthroscopic utilization.4 –13 Wrist arthroscopy is well recognized as an important adjunct for the diagnosis and treatment of wrist pathology; however, the role of midcarpal arthroscopy has not been adequately defined. In 1996, De Smet et al2 reported the results of a large group of patients who underwent wrist arthroscopy but they did not discern the role of midcarpal arthroscopy. In contrast, current textbooks of hand surgery have stated “no diagnostic arthroscopy is complete without evaluation of the midcarpal joint.”20 Past studies have tried to look at the utility of midcarpal arthroscopy. Fischer and Sennwald21,22 reported on 2 series of patients undergoing wrist arthroscopy. In both series 50% of carpal instability lesions could be identified on midcarpal arthroscopy. No conclusions regarding the role of midcarpal arthroscopy were made, however, nor was a compari-
Table 4. Additional Information Gained From Midcarpal Arthroscopy: 8 Intraarticular Distal Radius Fracture Cases Additional Diagnosis From Midcarpal Arthroscopy
No. of Patients (%)
Lunotriquetral instability Scapholunate instability Capitohamate instability23 Increase in severity
5 (62) 5 (62) 1 (12) 1 (12)
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 413
son of findings seen on radiocarpal versus midcarpal arthroscopy performed. In the present study, when instability of the scapholunate or lunotriquetral ligament was seen on radiocarpal arthroscopy, it was always seen on midcarpal arthroscopy. The corollary was not true. Additionally, midcarpal evaluation of instability was equal or greater than the instability assessed at the radiocarpal arthroscopy. This study clearly documents the utility of the midcarpal arthroscopic examination. All instabilities of the scapholunate or lunotriquetral ligaments discovered during a radiocarpal examination were verified at the midcarpal examination. The converse was not true, however; the majority of instabilities were not seen on radiocarpal arthroscopy when compared with midcarpal arthroscopy. Moreover, the grading of the ligamentous instability was always equal to or greater on the midcarpal examination. Other advantages of the midcarpal examination include visualization of the scaphoid–trapezoid–trapezium joint, midcarpal extrinsic ligaments, the capitohamate joint,23 and the articular surfaces of the midcarpal bones. Capitohamate instability was recently reported.23 Since this report we have routinely included the evaluation of the stability of the capitohamate joint, and evaluate it similarly to the scapholunate and lunotriquetral ligaments. Arthroscopy performed at the time of treatment of intra-articular distal radius fractures substantially increases the recognition of ligament injury24 –26; in the present study midcarpal arthroscopy further increased this recognition. The surgical technique of midcarpal arthroscopy can be mastered quickly; evaluation of this joint adds little to the operative time. As documented in this series and others,6,27 the morbidity rate is also low. We performed radiocarpal arthroscopy before midcarpal arthroscopy. The findings of radiocarpal arthroscopy may have influenced the findings seen at midcarpal arthroscopy. Although this bias could have been eliminated by performing midcarpal arthroscopy first in half of the cases, the goal of the study was to prove that radiocarpal arthroscopy alone may have missed or undergraded many lesions, because it is often performed alone. We do not advocate that midcarpal arthroscopy be performed without radiocarpal arthroscopy. Additional limitations of this study include the exclusion of a normal subject group. The potential for surgeon bias exists; however, in the cases that underwent arthrotomy the diagnosis was in concordance with the midcarpal findings.
This study clearly demonstrates that midcarpal arthroscopy yields significant information in addition to that found during a radiocarpal examination. This additional information alters the diagnosis and potential subsequent treatment. We believe that a complete wrist arthroscopic examination must include a midcarpal examination in addition to a radiocarpal examination. Wrist arthroscopy performed without a midcarpal examination is an incomplete evaluation of the wrist.
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