SCIENTIFIC ARTICLE
Ulnar Impaction Syndrome: Incidence of Lunotriquetral Ligament Degeneration and Outcome of Ulnar-Shortening Osteotomy Katsuyuki Iwatsuki, MD, PhD, Masahiro Tatebe, MD, PhD, Michiro Yamamoto, MD, PhD, Takaaki Shinohara, MD, PhD, Ryogo Nakamura, MD, PhD, Hitoshi Hirata, MD, PhD
Purpose We hypothesized that most patients with ulnar impaction syndrome have degenerative changes of the proximal lunotriquetral (LT) membrane and that ulnar-shortening osteotomy is an effective procedure in these patients. Methods We retrospectively reviewed 50 wrists of 49 patients with idiopathic ulnar impaction syndrome who underwent an arthroscopic evaluation at the time of ulnar-shortening osteotomy, and subsequently at plate removal. Based on the Geissler classification, patients were divided into group A, normal, and group B, grades I to IV. The degree of degeneration of the proximal LT membrane at first-look arthroscopy was compared with that at second-look arthroscopy. Results After ulnar-shortening osteotomy, both groups improved significantly in wrist range of motion and grip strength. According to the Mayo wrist score, 29, 18, and 3 patients showed excellent, good, and fair results, respectively. Of the 50 wrists, 25 had degenerative changes (group B) in the proximal LT membrane at the time of first-look arthroscopy. Of the 25 wrists in group B, 11 wrists improved based on the Geissler grade, 9 wrists showed no changes, and 2 wrists became worse. Clinically, patients demonstrated improvement after ulnar-shortening osteotomy regardless of the degree of degenerative LT ligament changes. Conclusions Degenerative LT membrane changes that were seen in about half of our patients were mostly of a mild nature, and the clinical outcomes of ulnar-shortening osteotomy were acceptable. (J Hand Surg Am. 2014;39(6):1108e1113. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Lunotriquetral ligament, ulnar-shortening osteotomy, ulnar impaction syndrome, ulnocarpal abutment syndrome, ulnocarpal impaction syndrome.
From the Department of Hand Surgery, Nagoya University Graduate School of Medicine; the Hand Surgery Center, Chunichi Hospital, Nagoya; and the Department of Orthopaedic Surgery, Anjo Kosei Hospital, Anjo, Japan. Received for publication November 3, 2013; accepted in revised form March 7, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Katsuyuki Iwatsuki, MD, PhD, Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; e-mail: [email protected]. 0363-5023/14/3906-0011$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.03.006
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LNAR-SIDED WRIST PAIN, A
common occurrence, has various etiologies ranging from an acute traumatic injury to a chronic degenerative condition. Common causes of ulnar-sided wrist pain include triangular fibrocartilage complex (TFCC) injuries, lunotriquetral (LT) ligament injury, and ulnar impaction syndrome.1,2 Ulnar impaction syndrome is frequently associated with the ulna-plus presentation3,4; however, it can also occur in wrists with either ulnar negative or neutral variance.5 It occurs in the presence of chronic
LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
impaction between the TFCC, the ulnar head, and the ulnar-sided carpus.6 Idiopathic ulnar impaction syndrome occurs in patients who have congenital or dynamic positive ulnar variance with wrist pronation and a forceful grip with no history of fracture or premature physeal arrest.7 This condition leads to mechanical erosion and perforation of the TFCC and the LT ligament.8,9 Palmer8 classified TFCC injury into class 1 (traumatic injuries) and class 2 (degenerative injuries). Based on this classification, ulnocarpal impaction syndrome was categorized as a class 2 or chronic lesion by Palmer, who described degenerative LT ligament changes resulting from the chronic load placed on the TFCC (class 2D). The LT ligament is the composite structure that includes the palmar and dorsal ligaments and the proximal membrane.10 The exact incidence of degenerative LT ligament changes among patients with ulnar impaction syndrome is unclear. In addition, the treatment options for degenerative LT ligament changes with ulnar impaction syndrome are not well described. Ulnar-shortening osteotomy (USO), described by Milch,3 is a treatment option for ulnar impaction syndrome and is advantageous because it allows preservation of the distal ulnar cartilage surface while the ulnocarpal ligamentous complex is tightened.7,11,12 However, few studies have addressed the management of degenerative changes in the LT ligament.13 The purposes of this study were to determine the incidence of degenerative LT ligament changes associated with idiopathic ulnar impaction syndrome and to review the results of USO for the treatment of these ligament changes. We hypothesized that most patients with chronic ulnar impaction syndrome also have degenerative LT ligament changes.
We excluded trauma cases such as injuries resulting from distal radius fractures. A total of 68 patients were diagnosed with idiopathic ulnar abutment syndrome. Plate removal and arthroscopy, which were refused by 16 patients, were performed at the patient’s discretion. In Japan, most patients do not want foreign materials left inside their bodies for their entire lifetime. In Japan, with the universal health coverage system, the costs for plate removal and second-look arthroscopy are much lower than those in countries without universal health coverage. We think this partly explains the marked difference in patients’ attitudes toward the surgery. Three patients underwent USO and temporary pinning of the LT joint for LT joint instability; these patients were excluded from the second-look arthroscopy and clinical evaluation. This retrospective study included 49 Asian patients with idiopathic ulnar impaction syndrome (25 men and 24 women), with a total of 50 wrists (31 right and 19 left, and 1 bilateral), who underwent first- and second-look arthroscopies for confirmation of degenerative LT changes. The mean patient age was 35 years (range, 15e73 y). All patients were right handed. No external funding was received for this investigation. Operative technique and arthroscopic assessment We made a longitudinal skin incision along the distal third of the ulna. The gap between the extensor carpi ulnaris and flexor carpi ulnaris was opened to expose the ulna dorsally. A 5-hole, 3.5-mm dynamic compression plate or a 5-hole, limited contact dynamic compression plate (DePuy Synthes, Tokyo, Japan) was placed on the surface of the ulna, and the 2 most distal screw holes were drilled and fixed temporarily. A longitudinal superficial saw cut was made on the ulna as a rotational marker. We removed the screws and plate and performed 2 parallel transverse osteotomies using an oscillating saw with a thin blade, removing approximately 2 to 6 mm of bone to adjust the ulnar variance to the contralateral side. The osteotomy site was fixed without malrotation using the same 3.5-mm plate in alignment with the previous mark on the ulna. Postoperative immobilization for 3 weeks was achieved using an above-elbow cast. We performed a second-look arthroscopy at the time of plate removal. Plates were removed at a mean of 19 months (range, 8e44 mo) after the osteotomy. Evaluation of the scapholunate (SL) and LT joints was done through midcarpal and radiocarpal portals.3 The Geissler classification16 was confirmed by palpation with a probe through the ulnar midcarpal portal at the time of USO (first-look arthroscopy) and
MATERIALS AND METHODS Our institutional review board approved this retrospective study. We reviewed patients with a diagnosis of idiopathic ulnar impaction syndrome who had undergone arthroscopic evaluations at the time of the USO, and later at plate removal between 1996 and 2011. Diagnosis of ulnar impaction syndrome was confirmed by radiography and arthroscopy.14 Patients provided written informed consent for plate removal and a second-look arthroscopic evaluation. Before the USO, all patients had ulnar-sided wrist pain, tenderness just distal to the dorsal or palmar aspect of the ulnar head, and a positive ulnocarpal stress test.15 These patients were experiencing severe pain despite undergoing conservative treatment such as splinting. Previous USOs had been performed in 119 patients. J Hand Surg Am.
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TABLE 1.
LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
Summary of Patient Data
Age, y
Group A
Group B
36 (15e63)
33 (15e73)
.85
15:13
10:12
.78
Sex, male:female
P Value
Length of ulnar shortening, mm
3.1 (2e6)
3.0 (2e4)
.12
Duration of symptoms, mo
11 (5e48)
20 (5e120)
.10
Preoperative flexion-extension (%)
89 (57e105)
81 (38e106)
.23
Preoperative grip strength (%)
85 (32e133)
72 (35e107)
.25
Postoperative flexion-extension (%) (1 y)
93 (62e109)
89 (50e106)
.94
Postoperative grip strength (%) (1 y)
96 (76e128)
100 (60e159)
.40
Postoperative flexion-extension (%) (final)
96 (88e122)
93 (77-127)
.75
Postoperative grip strength (%) (final)
98 (36e115)
95 (59e135)
.34
Data are shown as mean (range). In group A, LT findings were normal based on Geissler’s classification at first-look arthroscopy. In group B, LT findings were of Geissler grades I, II, III, and IV at first-look arthroscopy.
again at plate removal (second-look arthroscopy). Video imaging of each arthroscopy was recorded and later reviewed to evaluate the severity of degenerative LT ligament changes. The same surgeon performed the first and second arthroscopy assessments and the ulnar-shortening and plate removal. The arthroscopic video images were reviewed in a blinded fashion by one of the authors (K.I.) who did not perform the surgeries. The patients were divided into 2 groups based upon the Geissler classification of the LT findings: group A (normal) and group B (Geissler grades I, II, III, and IV). The primary outcome was assessed based on improvement of the Geissler grade.
obtained as follows: excellent, 90 to 100 points; good, 71 to 89 points; fair, 50 to 70 points; and poor, less than 50 points. Statistical methods We assessed normality of the distribution using the KolmogoroveSmirnov test; however, all data did not show normality. ManneWhitney test was used to assess differences between the groups and Wilcoxon signed-rank test was used to assess differences between preoperative and postoperative outcomes. Chisquare test was used to assess sex differences. P values less than .05 were considered statistically significant.
Radiological assessment A posteroanterior radiograph of the wrist was obtained with the shoulder in 90 abduction, the elbow in 90 flexion, the forearm in neutral rotation, and the wrist in neutral alignment, using the wrist support developed by Nakamura et al17 and Tatebe et al.18 Ulnar variance was measured to the nearest 0.5 mm using the method of perpendiculars.19 The SL angle was measured using lateral radiography for identification of volar intercalated segmental instability (VISI). An SL angle of less than 30 was judged to have static VISI deformity.
RESULTS Of 50 wrists, 25 were diagnosed with degenerative LT ligament changes at first-look arthroscopy and 25 had no degenerative LT ligament changes. Table 1 lists patient data. The average follow-up period was 39 months (range, 12e100 mo). There were no complications resulting from to the first and second wrist arthroscopic examinations and no incidences of osteotomy nonunion.21,22 The mean period for achieving union was 5 months (range, 3e11 mo). There were no marked preoperative differences between groups in terms of age, sex, or ulnar variance. None of the patients had a VISI deformity preoperatively or postoperatively. Table 2 shows the wrist scores at the final follow-up evaluation. During a clinical evaluation after the USO, patients demonstrated improvement regardless of the degree of degenerative LT ligament changes. Both groups significantly improved in range of motion and grip strength (Fig. 1). The SLs were classified as normal
Clinical evaluation The arc of motion and grip strength were recorded before surgery, at 1-year follow-up, and at final follow-up. The final wrist evaluation was made on the basis of the modified Mayo wrist score,20 which included an assessment of pain, functional status, wrist range of motion, and grip strength after the secondlook arthroscopy. The points assigned to each of the categories were accumulated, and a final rating was J Hand Surg Am.
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TABLE 2.
Mayo Wrist Score After Ulnar-Shortening Osteotomy
Mayo Wrist Score
Excellent
Good
Fair
Poor
Group A (N ¼ 28)
17
9
2
0
Group B (N ¼ 22)
12
9
1
0
5
6
0
0
Geissler’s classification Improved (N ¼ 11) No change (N ¼ 9)
6
3
0
0
Worse (N ¼ 2)
1
0
1
0
In group A, LT findings were normal based on Geissler’s classification at first-look arthroscopy. In group B, LT findings were of Geissler grades I, II, III, and IV at first-look arthroscopy.
FIGURE 1: A Change in wrist range of motion before (Pre) and after the operation. B Change in grip strength before and after the operation (*P < .05, **P < .01).
(35), grade I (4), grade II (8), grade III (3), and grade IV (0), based on the Geissler classification.16 Table 3 shows the LT changes in Geissler grade between the first- and second-look arthroscopic examinations. Improvements in Geissler grade had no significant relationship with clinical results.
had symptoms for twice as long as group A patients, as noted in Table 1. This finding is consistent with the theory that LT tears in ulnar impaction syndrome represent a more advanced stage of this process; however, the outcome of USO appeared to be adequate in both groups. We used midcarpal and radiocarpal portals to evaluate the dorsal and membranous component of LT ligament. Visualization of palmar LT ligament requires the use of a volar ulnar portal, and we did not employ that portal in this study. Instead, we judged the integrity of the ligament based on the Geissler classification.16 This study revealed that about 50% of the cases with idiopathic ulnar impaction syndrome had degenerative LT ligament changes, and that these lesions were generally mild, Geissler grade I or II tears. The
DISCUSSION Ulnar impaction syndrome is a degenerative condition of the ulnar side of the wrist. It is related to excessive load bearing across the ulnar carpus, the triangular fibrocartilage complex (TFCC), and the ulnar head.3 This condition has been reported to be the cause of LT ligament attenuation.8,9 In its advanced stage, the palmar and dorsal LT ligaments progressively stretch, leading to joint instability. Group B patients J Hand Surg Am.
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TABLE 3. Change in LT Stability, by Geissler Grade Between First- and Second-Look Arthroscopic Examinations Second Look First Look
Normal
Grade I
Grade II
Grade III
Grade IV
Normal (N ¼ 28)
24
0
4
0
0
Grade I (N ¼ 8)
4
4
0
0
0
Grade II (N ¼ 10)
3
0
5
1
1
Grade III (N ¼ 1)
0
1
0
0
0
Grade IV (N ¼ 3)
0
1
1
1
0
mechanism underlying degenerative changes in the LT ligament caused by ulnar impaction syndrome remains unknown; however, these results show that ulnar impaction syndrome seldom causes degenerative changes in the palmar and/or dorsal LT ligaments. The degenerative change is confined to the proximal membranous portion in most instances. This study showed that both groups were similar in age and ulnar variance. Therefore, a long ulna cannot be the exclusive cause of degenerative changes in the LT ligament. Reagan et al23 recognized disruption of the LT ligament as a specific carpal injury in 1984, which they described as a palmar and/or dorsal ligament injury. Treatment of LT ligament disruption remains controversial and has included joint arthrodesis, ligament repair, ligament reconstruction, and dorsal capsulodesis.13,24 Arthroscopic-assisted reduction and pinning has also been reported as 1 of the interventions for LT injuries.25 Although many studies have described acute LT ligament injuries, the treatment for degenerative changes in the LT ligament associated with ulnar impaction syndrome is still controversial. Moreover, a complete LT ligament tear is not sufficient to cause static VISI deformity.26 The current study reports degenerative changes in the LT ligament after USO with arthroscopic evaluation. In this study, 3 of 50 patients had severe instability, but the preoperative radiograph showed no VISI deformity, and good clinical results were achieved. Although USO is a treatment option for a TFCC tear, it can increase TFCC tension.27 The function of the TFCC is not yet fully understood. Some authors have reported that TFCC can prevent abnormal radioulnar translations of the carpus.28,29 The TFCC deep fibers and ulnocarpal ligaments have a common origin on the fovea and adhere to each other. The ulnocarpal ligaments, which consist of ulnolunate, ulnotriquetral, and ulnocapitate, have an important role in stabilizing the ulnocarpal joint.28e31 Therefore, USO increases J Hand Surg Am.
tension in not only the TFCC, but also the ulnocarpal ligaments. We graded LT joint stability based on the Geissler classification,16 which is the only arthroscopic system of intercarpal ligament injury classification and is widely used to assess LT and SL instability.32e35 Dohi et al32 reported a cadaveric study of the correlation between the Geissler classification and SL injury; however, the relationship between LT injury and the Geissler classification is still unknown. Half of our cases demonstrated improved Geissler grade after USO. Geissler grade improvement did not correlate with the clinical outcome. Fortunately, no arthroscopic complications occurred; however, the surgical morbidity cannot be ignored.22 Wrist arthroscopy for ulnar impaction syndrome is not necessary in the case of LT lesions; nevertheless, we believe that arthroscopy is useful for diagnosing and treating lesions in the articular cartilage and TFCC. We suggest that a future study should assess the reliability of arthroscopic analysis. Ulnar-shortening osteotomy has some disadvantages, including the use of a metal plate that often needs to be removed later and the potential complications of delayed union, nonunion, or stress fracture after plate removal.36,37 After sequential sets of radiographs confirmed healing of the osteotomy, we performed plate removal for most patients with a low risk for refracture.38 We encountered no cases of severe complications such as nonunion. A USO is a reasonable treatment for ulnar impaction with or without an LT tear. The current study had some limitations. First, the study was retrospective and had no control group. Degenerative LT ligament changes were detected only by arthroscopy. We could not examine the joint laxity in each case for a comparison with the contralateral side. In addition, a few weeks of splinting or casting could have made the LT ligament more stable, leading to the recovery of joint stability after the USO, and we r
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LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
do not know whether the Geissler stage would have improved with conservative treatment. Second, most LT lesions were mild; therefore, this theory may not be applicable to cases with severe LT lesions. Third, the small sample size may have limited the statistical power of the data. Fourth, we did not assess the changes in cartilage lesions around the LT joint after USO. Although the implications of these lesions in the context of symptoms have not been clarified, it would be interesting to know the extent of these changes as a result of USO. Fifth, we did not evaluate the relationship between the magnetic resonance imaging and arthroscopic findings. Our results suggest that USO is the first choice of treatment for ulnar impaction syndrome, irrespective of arthroscopic findings regarding LT ligament degeneration.
15. Nakamura R, Horii E, Imaeda T, Nakao E, Kato H, Watanabe K. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg Br. 1997;22(6):719e723. 16. 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 Am. 1996;78(3): 357e365. 17. Nakamura R, Hori M, Imamura T, Horii E, Miura T. Method for measurement and evaluation of carpal bone angles. J Hand Surg Am. 1989;14(2 pt 2):412e416. 18. Tatebe M, Nakamura R, Horii E, Nakao E. Results of ulnar shortening osteotomy for ulnocarpal impaction syndrome in wrists with neutral or negative ulnar variance. J Hand Surg Br. 2005;30(2): 129e132. 19. Steyers CM, Blair WF. Measuring ulnar variance: a comparison of techniques. J Hand Surg Am. 1989;14(4):607e612. 20. Cooney WP, Bussey R, Dobyns JH, Linscheid RL. Difficult wrist fractures: perilunate fracture-dislocations of the wrist. Clin Orthop Relat Res. 1987;214:136e147. 21. Culp RW. Complications of wrist arthroscopy. Hand Clin. 1999;15(3):529e535, x. 22. Beredjiklian PK, Bozentka DJ, Leung YL, Monaghan BA. Complications of wrist arthroscopy. J Hand Surg Am. 2004;29(3):406e411. 23. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg Am. 1984;9(4):502e514. 24. Omokawa S, Fujitani R, Inada Y. Dorsal radiocarpal ligament capsulodesis for chronic dynamic lunotriquetral instability. J Hand Surg Am. 2009;34(2):237e243. 25. Weiss LE, Taras JS, Sweet S, Osterman AL. Lunotriquetral injuries in the athlete. Hand Clin. 2000;16(3):433e438. 26. Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability: diagnosis and treatment. J Am Acad Orthop Surg. 2000;8(3):170e179. 27. Tatebe M, Horii E, Nakao E, et al. Repair of the triangular fibrocartilage complex after ulnar-shortening osteotomy: second-look arthroscopy. J Hand Surg Am. 2007;32(4):445e449. 28. Weaver L, Tencer AF, Trumble TE. Tensions in the palmar ligaments of the wrist. I. The normal wrist. J Hand Surg Am. 1994;19(3):464e474. 29. Wiesner L, Rumelhart C, Pham E, Comtet JJ. Experimentally induced ulno-carpal instability: a study on 13 cadaver wrists. J Hand Surg Br. 1996;21(1):24e29. 30. Moritomo H, Murase T, Arimitsu S, Oka K, Yoshikawa H, Sugamoto K. Change in the length of the ulnocarpal ligaments during radiocarpal motion: possible impact on triangular fibrocartilage complex foveal tears. J Hand Surg Am. 2008;33(8):1278e1286. 31. Nishikawa S, Toh S. Anatomical study of the carpal attachment of the triangular fibrocartilage complex. J Bone Joint Surg Br. 2002;84(7): 1062e1065. 32. Dohi Y, Omokawa S, Ono H, et al. Arthroscopic gap distance can predict the degree of scapholunate ligament tears: a cadaver study. J Orthop Sci. 2012;17(1):64e69. 33. Slutsky DJ. Incidence of dorsal radiocarpal ligament tears in the presence of other intercarpal derangements. Arthroscopy. 2008;24(5): 526e533. 34. Rimington TR, Edwards SG, Lynch TS, Pehlivanova MB. Intercarpal ligamentous laxity in cadaveric wrists. J Bone Joint Surg Br. 2010;92(11):1600e1605. 35. Tan SW, Ng SW, Tan SH, Teoh LC. Arthroscopic debridement of intercarpal ligament and triangular fibrocartilage complex tears. Singapore Med J. 2012;53(3):188e191. 36. Boulas HJ, Milek MA. Ulnar shortening for tears of the triangular fibrocartilaginous complex. J Hand Surg Am. 1990;15(3):415e420. 37. Constantine KJ, Tomaino MM, Herndon JH, Sotereanos DG. Comparison of ulnar shortening osteotomy and the wafer resection procedure as treatment for ulnar impaction syndrome. J Hand Surg Am. 2000;25(1):55e60. 38. Pomerance J. Plate removal after ulnar-shortening osteotomy. J Hand Surg Am. 2005;30(5):949e953.
REFERENCES 1. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist—anatomy and function. J Hand Surg Am. 1981;6(2):153e162. 2. Shin AY, Weinstein LP, Berger RA, Bishop AT. Treatment of isolated injuries of the lunotriquetral ligament: a comparison of arthrodesis, ligament reconstruction and ligament repair. J Bone Joint Surg Br. 2001;83(7):1023e1028. 3. Milch H. Cuff resection of the ulna for malunited Colles’ fracture. J Bone Joint Surg. 1941;23:311e313. 4. Tatebe M, Nakamura R, Horii E, Nakao E, Inagaki H. Ulnocarpal impaction syndrome restricts even midcarpal range of motion. Hand Surg. 2005;10(1):23e27. 5. Tomaino MM. Ulnar impaction syndrome in the ulnar negative and neutral wrist: diagnosis and pathoanatomy. J Hand Surg Br. 1998;23(6): 754e757. 6. Bickel KD. Arthroscopic treatment of ulnar impaction syndrome. J Hand Surg Am. 2008;33(8):1420e1423. 7. Baek GH, Chung MS, Lee YH, Gong HS, Lee S, Kim HH. Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome. J Bone Joint Surg Am. 2005;87(12):2649e2654. 8. Palmer AK. Triangular fibrocartilage complex lesions: a classification. J Hand Surg Am. 1989;14(4):594e606. 9. Nishiwaki M, Nakamura T, Nagura T, Toyama Y, Ikegami H. Ulnarshortening effect on distal radioulnar joint pressure: a biomechanical study. J Hand Surg Am. 2008;33(2):198e205. 10. Sachar K. Ulnar-sided wrist pain: evaluation and treatment of triangular fibrocartilage complex tears, ulnocarpal impaction syndrome, and lunotriquetral ligament tears. J Hand Surg Am. 2008;33(9): 1669e1679. 11. Iwasaki N, Ishikawa J, Kato H, Minami M, Minami A. Factors affecting results of ulnar shortening for ulnar impaction syndrome. Clin Orthop Relat Res. 2007;465:215e219. 12. Moermans A, Degreef I, De Smet L. Ulnar shortening osteotomy for ulnar idiopathic impaction syndrome. Scand J Plast Reconstr Surg Hand Surg. 2007;41(6):310e314. 13. Mirza A, Mirza JB, Shin AY, Lorenzana DJ, Lee BK, Izzo B. Isolated lunotriquetral ligament tears treated with ulnar shortening osteotomy. J Hand Surg Am. 2013;38(8):1492e1497. 14. Nishizuka T, Tatebe M, Hirata H, Shinohara T, Yamamoto M, Iwatsuki K. Simple debridement has little useful value on the clinical course of recalcitrant ulnar wrist pain. Bone Joint J. 2013;95-B(12): 1687e1696.
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Ulnar Impaction Syndrome: Incidence of Lunotriquetral Ligament Degeneration and Outcome of Ulnar-Shortening Osteotomy Katsuyuki Iwatsuki, MD, PhD, Masahiro Tatebe, MD, PhD, Michiro Yamamoto, MD, PhD, Takaaki Shinohara, MD, PhD, Ryogo Nakamura, MD, PhD, Hitoshi Hirata, MD, PhD
Purpose We hypothesized that most patients with ulnar impaction syndrome have degenerative changes of the proximal lunotriquetral (LT) membrane and that ulnar-shortening osteotomy is an effective procedure in these patients. Methods We retrospectively reviewed 50 wrists of 49 patients with idiopathic ulnar impaction syndrome who underwent an arthroscopic evaluation at the time of ulnar-shortening osteotomy, and subsequently at plate removal. Based on the Geissler classification, patients were divided into group A, normal, and group B, grades I to IV. The degree of degeneration of the proximal LT membrane at first-look arthroscopy was compared with that at second-look arthroscopy. Results After ulnar-shortening osteotomy, both groups improved significantly in wrist range of motion and grip strength. According to the Mayo wrist score, 29, 18, and 3 patients showed excellent, good, and fair results, respectively. Of the 50 wrists, 25 had degenerative changes (group B) in the proximal LT membrane at the time of first-look arthroscopy. Of the 25 wrists in group B, 11 wrists improved based on the Geissler grade, 9 wrists showed no changes, and 2 wrists became worse. Clinically, patients demonstrated improvement after ulnar-shortening osteotomy regardless of the degree of degenerative LT ligament changes. Conclusions Degenerative LT membrane changes that were seen in about half of our patients were mostly of a mild nature, and the clinical outcomes of ulnar-shortening osteotomy were acceptable. (J Hand Surg Am. 2014;39(6):1108e1113. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Lunotriquetral ligament, ulnar-shortening osteotomy, ulnar impaction syndrome, ulnocarpal abutment syndrome, ulnocarpal impaction syndrome.
From the Department of Hand Surgery, Nagoya University Graduate School of Medicine; the Hand Surgery Center, Chunichi Hospital, Nagoya; and the Department of Orthopaedic Surgery, Anjo Kosei Hospital, Anjo, Japan. Received for publication November 3, 2013; accepted in revised form March 7, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Katsuyuki Iwatsuki, MD, PhD, Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; e-mail: [email protected]. 0363-5023/14/3906-0011$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.03.006
1108
r
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
U
LNAR-SIDED WRIST PAIN, A
common occurrence, has various etiologies ranging from an acute traumatic injury to a chronic degenerative condition. Common causes of ulnar-sided wrist pain include triangular fibrocartilage complex (TFCC) injuries, lunotriquetral (LT) ligament injury, and ulnar impaction syndrome.1,2 Ulnar impaction syndrome is frequently associated with the ulna-plus presentation3,4; however, it can also occur in wrists with either ulnar negative or neutral variance.5 It occurs in the presence of chronic
LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
impaction between the TFCC, the ulnar head, and the ulnar-sided carpus.6 Idiopathic ulnar impaction syndrome occurs in patients who have congenital or dynamic positive ulnar variance with wrist pronation and a forceful grip with no history of fracture or premature physeal arrest.7 This condition leads to mechanical erosion and perforation of the TFCC and the LT ligament.8,9 Palmer8 classified TFCC injury into class 1 (traumatic injuries) and class 2 (degenerative injuries). Based on this classification, ulnocarpal impaction syndrome was categorized as a class 2 or chronic lesion by Palmer, who described degenerative LT ligament changes resulting from the chronic load placed on the TFCC (class 2D). The LT ligament is the composite structure that includes the palmar and dorsal ligaments and the proximal membrane.10 The exact incidence of degenerative LT ligament changes among patients with ulnar impaction syndrome is unclear. In addition, the treatment options for degenerative LT ligament changes with ulnar impaction syndrome are not well described. Ulnar-shortening osteotomy (USO), described by Milch,3 is a treatment option for ulnar impaction syndrome and is advantageous because it allows preservation of the distal ulnar cartilage surface while the ulnocarpal ligamentous complex is tightened.7,11,12 However, few studies have addressed the management of degenerative changes in the LT ligament.13 The purposes of this study were to determine the incidence of degenerative LT ligament changes associated with idiopathic ulnar impaction syndrome and to review the results of USO for the treatment of these ligament changes. We hypothesized that most patients with chronic ulnar impaction syndrome also have degenerative LT ligament changes.
We excluded trauma cases such as injuries resulting from distal radius fractures. A total of 68 patients were diagnosed with idiopathic ulnar abutment syndrome. Plate removal and arthroscopy, which were refused by 16 patients, were performed at the patient’s discretion. In Japan, most patients do not want foreign materials left inside their bodies for their entire lifetime. In Japan, with the universal health coverage system, the costs for plate removal and second-look arthroscopy are much lower than those in countries without universal health coverage. We think this partly explains the marked difference in patients’ attitudes toward the surgery. Three patients underwent USO and temporary pinning of the LT joint for LT joint instability; these patients were excluded from the second-look arthroscopy and clinical evaluation. This retrospective study included 49 Asian patients with idiopathic ulnar impaction syndrome (25 men and 24 women), with a total of 50 wrists (31 right and 19 left, and 1 bilateral), who underwent first- and second-look arthroscopies for confirmation of degenerative LT changes. The mean patient age was 35 years (range, 15e73 y). All patients were right handed. No external funding was received for this investigation. Operative technique and arthroscopic assessment We made a longitudinal skin incision along the distal third of the ulna. The gap between the extensor carpi ulnaris and flexor carpi ulnaris was opened to expose the ulna dorsally. A 5-hole, 3.5-mm dynamic compression plate or a 5-hole, limited contact dynamic compression plate (DePuy Synthes, Tokyo, Japan) was placed on the surface of the ulna, and the 2 most distal screw holes were drilled and fixed temporarily. A longitudinal superficial saw cut was made on the ulna as a rotational marker. We removed the screws and plate and performed 2 parallel transverse osteotomies using an oscillating saw with a thin blade, removing approximately 2 to 6 mm of bone to adjust the ulnar variance to the contralateral side. The osteotomy site was fixed without malrotation using the same 3.5-mm plate in alignment with the previous mark on the ulna. Postoperative immobilization for 3 weeks was achieved using an above-elbow cast. We performed a second-look arthroscopy at the time of plate removal. Plates were removed at a mean of 19 months (range, 8e44 mo) after the osteotomy. Evaluation of the scapholunate (SL) and LT joints was done through midcarpal and radiocarpal portals.3 The Geissler classification16 was confirmed by palpation with a probe through the ulnar midcarpal portal at the time of USO (first-look arthroscopy) and
MATERIALS AND METHODS Our institutional review board approved this retrospective study. We reviewed patients with a diagnosis of idiopathic ulnar impaction syndrome who had undergone arthroscopic evaluations at the time of the USO, and later at plate removal between 1996 and 2011. Diagnosis of ulnar impaction syndrome was confirmed by radiography and arthroscopy.14 Patients provided written informed consent for plate removal and a second-look arthroscopic evaluation. Before the USO, all patients had ulnar-sided wrist pain, tenderness just distal to the dorsal or palmar aspect of the ulnar head, and a positive ulnocarpal stress test.15 These patients were experiencing severe pain despite undergoing conservative treatment such as splinting. Previous USOs had been performed in 119 patients. J Hand Surg Am.
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TABLE 1.
LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
Summary of Patient Data
Age, y
Group A
Group B
36 (15e63)
33 (15e73)
.85
15:13
10:12
.78
Sex, male:female
P Value
Length of ulnar shortening, mm
3.1 (2e6)
3.0 (2e4)
.12
Duration of symptoms, mo
11 (5e48)
20 (5e120)
.10
Preoperative flexion-extension (%)
89 (57e105)
81 (38e106)
.23
Preoperative grip strength (%)
85 (32e133)
72 (35e107)
.25
Postoperative flexion-extension (%) (1 y)
93 (62e109)
89 (50e106)
.94
Postoperative grip strength (%) (1 y)
96 (76e128)
100 (60e159)
.40
Postoperative flexion-extension (%) (final)
96 (88e122)
93 (77-127)
.75
Postoperative grip strength (%) (final)
98 (36e115)
95 (59e135)
.34
Data are shown as mean (range). In group A, LT findings were normal based on Geissler’s classification at first-look arthroscopy. In group B, LT findings were of Geissler grades I, II, III, and IV at first-look arthroscopy.
again at plate removal (second-look arthroscopy). Video imaging of each arthroscopy was recorded and later reviewed to evaluate the severity of degenerative LT ligament changes. The same surgeon performed the first and second arthroscopy assessments and the ulnar-shortening and plate removal. The arthroscopic video images were reviewed in a blinded fashion by one of the authors (K.I.) who did not perform the surgeries. The patients were divided into 2 groups based upon the Geissler classification of the LT findings: group A (normal) and group B (Geissler grades I, II, III, and IV). The primary outcome was assessed based on improvement of the Geissler grade.
obtained as follows: excellent, 90 to 100 points; good, 71 to 89 points; fair, 50 to 70 points; and poor, less than 50 points. Statistical methods We assessed normality of the distribution using the KolmogoroveSmirnov test; however, all data did not show normality. ManneWhitney test was used to assess differences between the groups and Wilcoxon signed-rank test was used to assess differences between preoperative and postoperative outcomes. Chisquare test was used to assess sex differences. P values less than .05 were considered statistically significant.
Radiological assessment A posteroanterior radiograph of the wrist was obtained with the shoulder in 90 abduction, the elbow in 90 flexion, the forearm in neutral rotation, and the wrist in neutral alignment, using the wrist support developed by Nakamura et al17 and Tatebe et al.18 Ulnar variance was measured to the nearest 0.5 mm using the method of perpendiculars.19 The SL angle was measured using lateral radiography for identification of volar intercalated segmental instability (VISI). An SL angle of less than 30 was judged to have static VISI deformity.
RESULTS Of 50 wrists, 25 were diagnosed with degenerative LT ligament changes at first-look arthroscopy and 25 had no degenerative LT ligament changes. Table 1 lists patient data. The average follow-up period was 39 months (range, 12e100 mo). There were no complications resulting from to the first and second wrist arthroscopic examinations and no incidences of osteotomy nonunion.21,22 The mean period for achieving union was 5 months (range, 3e11 mo). There were no marked preoperative differences between groups in terms of age, sex, or ulnar variance. None of the patients had a VISI deformity preoperatively or postoperatively. Table 2 shows the wrist scores at the final follow-up evaluation. During a clinical evaluation after the USO, patients demonstrated improvement regardless of the degree of degenerative LT ligament changes. Both groups significantly improved in range of motion and grip strength (Fig. 1). The SLs were classified as normal
Clinical evaluation The arc of motion and grip strength were recorded before surgery, at 1-year follow-up, and at final follow-up. The final wrist evaluation was made on the basis of the modified Mayo wrist score,20 which included an assessment of pain, functional status, wrist range of motion, and grip strength after the secondlook arthroscopy. The points assigned to each of the categories were accumulated, and a final rating was J Hand Surg Am.
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TABLE 2.
Mayo Wrist Score After Ulnar-Shortening Osteotomy
Mayo Wrist Score
Excellent
Good
Fair
Poor
Group A (N ¼ 28)
17
9
2
0
Group B (N ¼ 22)
12
9
1
0
5
6
0
0
Geissler’s classification Improved (N ¼ 11) No change (N ¼ 9)
6
3
0
0
Worse (N ¼ 2)
1
0
1
0
In group A, LT findings were normal based on Geissler’s classification at first-look arthroscopy. In group B, LT findings were of Geissler grades I, II, III, and IV at first-look arthroscopy.
FIGURE 1: A Change in wrist range of motion before (Pre) and after the operation. B Change in grip strength before and after the operation (*P < .05, **P < .01).
(35), grade I (4), grade II (8), grade III (3), and grade IV (0), based on the Geissler classification.16 Table 3 shows the LT changes in Geissler grade between the first- and second-look arthroscopic examinations. Improvements in Geissler grade had no significant relationship with clinical results.
had symptoms for twice as long as group A patients, as noted in Table 1. This finding is consistent with the theory that LT tears in ulnar impaction syndrome represent a more advanced stage of this process; however, the outcome of USO appeared to be adequate in both groups. We used midcarpal and radiocarpal portals to evaluate the dorsal and membranous component of LT ligament. Visualization of palmar LT ligament requires the use of a volar ulnar portal, and we did not employ that portal in this study. Instead, we judged the integrity of the ligament based on the Geissler classification.16 This study revealed that about 50% of the cases with idiopathic ulnar impaction syndrome had degenerative LT ligament changes, and that these lesions were generally mild, Geissler grade I or II tears. The
DISCUSSION Ulnar impaction syndrome is a degenerative condition of the ulnar side of the wrist. It is related to excessive load bearing across the ulnar carpus, the triangular fibrocartilage complex (TFCC), and the ulnar head.3 This condition has been reported to be the cause of LT ligament attenuation.8,9 In its advanced stage, the palmar and dorsal LT ligaments progressively stretch, leading to joint instability. Group B patients J Hand Surg Am.
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TABLE 3. Change in LT Stability, by Geissler Grade Between First- and Second-Look Arthroscopic Examinations Second Look First Look
Normal
Grade I
Grade II
Grade III
Grade IV
Normal (N ¼ 28)
24
0
4
0
0
Grade I (N ¼ 8)
4
4
0
0
0
Grade II (N ¼ 10)
3
0
5
1
1
Grade III (N ¼ 1)
0
1
0
0
0
Grade IV (N ¼ 3)
0
1
1
1
0
mechanism underlying degenerative changes in the LT ligament caused by ulnar impaction syndrome remains unknown; however, these results show that ulnar impaction syndrome seldom causes degenerative changes in the palmar and/or dorsal LT ligaments. The degenerative change is confined to the proximal membranous portion in most instances. This study showed that both groups were similar in age and ulnar variance. Therefore, a long ulna cannot be the exclusive cause of degenerative changes in the LT ligament. Reagan et al23 recognized disruption of the LT ligament as a specific carpal injury in 1984, which they described as a palmar and/or dorsal ligament injury. Treatment of LT ligament disruption remains controversial and has included joint arthrodesis, ligament repair, ligament reconstruction, and dorsal capsulodesis.13,24 Arthroscopic-assisted reduction and pinning has also been reported as 1 of the interventions for LT injuries.25 Although many studies have described acute LT ligament injuries, the treatment for degenerative changes in the LT ligament associated with ulnar impaction syndrome is still controversial. Moreover, a complete LT ligament tear is not sufficient to cause static VISI deformity.26 The current study reports degenerative changes in the LT ligament after USO with arthroscopic evaluation. In this study, 3 of 50 patients had severe instability, but the preoperative radiograph showed no VISI deformity, and good clinical results were achieved. Although USO is a treatment option for a TFCC tear, it can increase TFCC tension.27 The function of the TFCC is not yet fully understood. Some authors have reported that TFCC can prevent abnormal radioulnar translations of the carpus.28,29 The TFCC deep fibers and ulnocarpal ligaments have a common origin on the fovea and adhere to each other. The ulnocarpal ligaments, which consist of ulnolunate, ulnotriquetral, and ulnocapitate, have an important role in stabilizing the ulnocarpal joint.28e31 Therefore, USO increases J Hand Surg Am.
tension in not only the TFCC, but also the ulnocarpal ligaments. We graded LT joint stability based on the Geissler classification,16 which is the only arthroscopic system of intercarpal ligament injury classification and is widely used to assess LT and SL instability.32e35 Dohi et al32 reported a cadaveric study of the correlation between the Geissler classification and SL injury; however, the relationship between LT injury and the Geissler classification is still unknown. Half of our cases demonstrated improved Geissler grade after USO. Geissler grade improvement did not correlate with the clinical outcome. Fortunately, no arthroscopic complications occurred; however, the surgical morbidity cannot be ignored.22 Wrist arthroscopy for ulnar impaction syndrome is not necessary in the case of LT lesions; nevertheless, we believe that arthroscopy is useful for diagnosing and treating lesions in the articular cartilage and TFCC. We suggest that a future study should assess the reliability of arthroscopic analysis. Ulnar-shortening osteotomy has some disadvantages, including the use of a metal plate that often needs to be removed later and the potential complications of delayed union, nonunion, or stress fracture after plate removal.36,37 After sequential sets of radiographs confirmed healing of the osteotomy, we performed plate removal for most patients with a low risk for refracture.38 We encountered no cases of severe complications such as nonunion. A USO is a reasonable treatment for ulnar impaction with or without an LT tear. The current study had some limitations. First, the study was retrospective and had no control group. Degenerative LT ligament changes were detected only by arthroscopy. We could not examine the joint laxity in each case for a comparison with the contralateral side. In addition, a few weeks of splinting or casting could have made the LT ligament more stable, leading to the recovery of joint stability after the USO, and we r
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LIGAMENT CHANGE OF ULNAR-SHORTENING OSTEOTOMY
do not know whether the Geissler stage would have improved with conservative treatment. Second, most LT lesions were mild; therefore, this theory may not be applicable to cases with severe LT lesions. Third, the small sample size may have limited the statistical power of the data. Fourth, we did not assess the changes in cartilage lesions around the LT joint after USO. Although the implications of these lesions in the context of symptoms have not been clarified, it would be interesting to know the extent of these changes as a result of USO. Fifth, we did not evaluate the relationship between the magnetic resonance imaging and arthroscopic findings. Our results suggest that USO is the first choice of treatment for ulnar impaction syndrome, irrespective of arthroscopic findings regarding LT ligament degeneration.
15. Nakamura R, Horii E, Imaeda T, Nakao E, Kato H, Watanabe K. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg Br. 1997;22(6):719e723. 16. 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 Am. 1996;78(3): 357e365. 17. Nakamura R, Hori M, Imamura T, Horii E, Miura T. Method for measurement and evaluation of carpal bone angles. J Hand Surg Am. 1989;14(2 pt 2):412e416. 18. Tatebe M, Nakamura R, Horii E, Nakao E. Results of ulnar shortening osteotomy for ulnocarpal impaction syndrome in wrists with neutral or negative ulnar variance. J Hand Surg Br. 2005;30(2): 129e132. 19. Steyers CM, Blair WF. Measuring ulnar variance: a comparison of techniques. J Hand Surg Am. 1989;14(4):607e612. 20. Cooney WP, Bussey R, Dobyns JH, Linscheid RL. Difficult wrist fractures: perilunate fracture-dislocations of the wrist. Clin Orthop Relat Res. 1987;214:136e147. 21. Culp RW. Complications of wrist arthroscopy. Hand Clin. 1999;15(3):529e535, x. 22. Beredjiklian PK, Bozentka DJ, Leung YL, Monaghan BA. Complications of wrist arthroscopy. J Hand Surg Am. 2004;29(3):406e411. 23. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg Am. 1984;9(4):502e514. 24. Omokawa S, Fujitani R, Inada Y. Dorsal radiocarpal ligament capsulodesis for chronic dynamic lunotriquetral instability. J Hand Surg Am. 2009;34(2):237e243. 25. Weiss LE, Taras JS, Sweet S, Osterman AL. Lunotriquetral injuries in the athlete. Hand Clin. 2000;16(3):433e438. 26. Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability: diagnosis and treatment. J Am Acad Orthop Surg. 2000;8(3):170e179. 27. Tatebe M, Horii E, Nakao E, et al. Repair of the triangular fibrocartilage complex after ulnar-shortening osteotomy: second-look arthroscopy. J Hand Surg Am. 2007;32(4):445e449. 28. Weaver L, Tencer AF, Trumble TE. Tensions in the palmar ligaments of the wrist. I. The normal wrist. J Hand Surg Am. 1994;19(3):464e474. 29. Wiesner L, Rumelhart C, Pham E, Comtet JJ. Experimentally induced ulno-carpal instability: a study on 13 cadaver wrists. J Hand Surg Br. 1996;21(1):24e29. 30. Moritomo H, Murase T, Arimitsu S, Oka K, Yoshikawa H, Sugamoto K. Change in the length of the ulnocarpal ligaments during radiocarpal motion: possible impact on triangular fibrocartilage complex foveal tears. J Hand Surg Am. 2008;33(8):1278e1286. 31. Nishikawa S, Toh S. Anatomical study of the carpal attachment of the triangular fibrocartilage complex. J Bone Joint Surg Br. 2002;84(7): 1062e1065. 32. Dohi Y, Omokawa S, Ono H, et al. Arthroscopic gap distance can predict the degree of scapholunate ligament tears: a cadaver study. J Orthop Sci. 2012;17(1):64e69. 33. Slutsky DJ. Incidence of dorsal radiocarpal ligament tears in the presence of other intercarpal derangements. Arthroscopy. 2008;24(5): 526e533. 34. Rimington TR, Edwards SG, Lynch TS, Pehlivanova MB. Intercarpal ligamentous laxity in cadaveric wrists. J Bone Joint Surg Br. 2010;92(11):1600e1605. 35. Tan SW, Ng SW, Tan SH, Teoh LC. Arthroscopic debridement of intercarpal ligament and triangular fibrocartilage complex tears. Singapore Med J. 2012;53(3):188e191. 36. Boulas HJ, Milek MA. Ulnar shortening for tears of the triangular fibrocartilaginous complex. J Hand Surg Am. 1990;15(3):415e420. 37. Constantine KJ, Tomaino MM, Herndon JH, Sotereanos DG. Comparison of ulnar shortening osteotomy and the wafer resection procedure as treatment for ulnar impaction syndrome. J Hand Surg Am. 2000;25(1):55e60. 38. Pomerance J. Plate removal after ulnar-shortening osteotomy. J Hand Surg Am. 2005;30(5):949e953.
REFERENCES 1. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist—anatomy and function. J Hand Surg Am. 1981;6(2):153e162. 2. Shin AY, Weinstein LP, Berger RA, Bishop AT. Treatment of isolated injuries of the lunotriquetral ligament: a comparison of arthrodesis, ligament reconstruction and ligament repair. J Bone Joint Surg Br. 2001;83(7):1023e1028. 3. Milch H. Cuff resection of the ulna for malunited Colles’ fracture. J Bone Joint Surg. 1941;23:311e313. 4. Tatebe M, Nakamura R, Horii E, Nakao E, Inagaki H. Ulnocarpal impaction syndrome restricts even midcarpal range of motion. Hand Surg. 2005;10(1):23e27. 5. Tomaino MM. Ulnar impaction syndrome in the ulnar negative and neutral wrist: diagnosis and pathoanatomy. J Hand Surg Br. 1998;23(6): 754e757. 6. Bickel KD. Arthroscopic treatment of ulnar impaction syndrome. J Hand Surg Am. 2008;33(8):1420e1423. 7. Baek GH, Chung MS, Lee YH, Gong HS, Lee S, Kim HH. Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome. J Bone Joint Surg Am. 2005;87(12):2649e2654. 8. Palmer AK. Triangular fibrocartilage complex lesions: a classification. J Hand Surg Am. 1989;14(4):594e606. 9. Nishiwaki M, Nakamura T, Nagura T, Toyama Y, Ikegami H. Ulnarshortening effect on distal radioulnar joint pressure: a biomechanical study. J Hand Surg Am. 2008;33(2):198e205. 10. Sachar K. Ulnar-sided wrist pain: evaluation and treatment of triangular fibrocartilage complex tears, ulnocarpal impaction syndrome, and lunotriquetral ligament tears. J Hand Surg Am. 2008;33(9): 1669e1679. 11. Iwasaki N, Ishikawa J, Kato H, Minami M, Minami A. Factors affecting results of ulnar shortening for ulnar impaction syndrome. Clin Orthop Relat Res. 2007;465:215e219. 12. Moermans A, Degreef I, De Smet L. Ulnar shortening osteotomy for ulnar idiopathic impaction syndrome. Scand J Plast Reconstr Surg Hand Surg. 2007;41(6):310e314. 13. Mirza A, Mirza JB, Shin AY, Lorenzana DJ, Lee BK, Izzo B. Isolated lunotriquetral ligament tears treated with ulnar shortening osteotomy. J Hand Surg Am. 2013;38(8):1492e1497. 14. Nishizuka T, Tatebe M, Hirata H, Shinohara T, Yamamoto M, Iwatsuki K. Simple debridement has little useful value on the clinical course of recalcitrant ulnar wrist pain. Bone Joint J. 2013;95-B(12): 1687e1696.
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